JP2014040874A - Lubrication structure of shaft member - Google Patents

Abstract

[PROBLEMS] To supply oil from an outer peripheral side of a shaft member to an inner hollow portion, and to easily install an oil seal disposed on the outer side in the axial direction of a bearing and to prevent oil from leaking outside from the oil seal. A lubrication structure for a shaft member that enables lubrication of the inner hollow portion of the shaft member.
SOLUTION: At least one annular oil seal 40 is inserted in the inner peripheral surface of a bearing opening 1e of a case 1 that rotatably supports a shaft member 9 via a bearing 7L, on the axially outer side from the bearing. A case-side oil passage y that is fitted and supplied with oil is drilled in the bearing opening so as to have an oil passage opening 1x on the inner peripheral surface between the bearing and the annular oil seal, and is hollow inside the shaft member. In the lubricating structure of the shaft member in which the shaft member-side oil hole 12x for supplying oil from the outer peripheral side to the portion is formed in the shaft member, the shaft is provided on the inner side in the axial direction of the annular oil seal and on the outer side in the axial direction from the oil passage opening An annular labyrinth seal 41 was provided through the member.
[Selection] Figure 17

Description

  The present invention relates to a lubricating structure for introducing lubricating oil into an inner hollow portion of a shaft member that is rotatably supported.

In the case where the cylindrical shaft member is rotatably supported by the bearing portion of the case via the bearing, the end of the shaft member is covered with a case-side lid, and the inside of the shaft member is passed through the oil passage in the lid. Generally, lubricating oil (hereinafter simply referred to as “oil”) is introduced into the hollow portion.
However, when it is difficult to form an oil passage by attaching various mechanisms to both ends of the shaft member, there are those that adopt a lubricating oil passage structure from the outer peripheral side near the bearing to the inner hollow portion of the intermediate portion of the shaft member. For example, it is shown in the following Patent Document 1.

Patent Document 1 is an invention related to a lubrication structure for a multi-stage transmission previously filed by the present applicant. The multi-stage transmission disclosed in Patent Document 1 is a gear that is integral with a main gear shaft and a counter gear shaft. A gear that is rotatably supported by a shaft is always meshed, and a gear that effectively acts on the counter gear shaft is selected by an engagement switching mechanism in the counter gear shaft to perform speed change.
The counter gear shaft with an engagement switching mechanism inside is provided with an output sprocket at one end and a shift mechanism for shifting at the other end, so that oil is supplied from the shaft end to the engagement switching mechanism in the inner hollow portion. Since it cannot be introduced, oil is introduced from the outer peripheral side of the counter gear shaft as the shaft member.

In what is disclosed in Patent Document 1, a double-structure oil seal is provided on the outer side in the axial direction of the bearing of the shaft member, and in the middle of the double oil seal, the shaft member communicates with the inner hollow portion from the outer peripheral side. A supply hole is formed.
On the other hand, a case-side oil passage for supplying oil is formed in the bearing opening of the case that supports the bearing, and opens in the middle of the double oil seal.
According to such a structure, the oil supply path from the outer peripheral side of the intermediate part of the shaft member to the inner hollow part can be set.
However, in such a structure, oil pressure is applied between the double oil seals. For example, if the elastic lip of the oil seal is turned over when the oil seal is installed, the oil may leak, Had the task of requiring attention.

JP 2012-77795 A (FIGS. 3, 5, and 15 to 20)

  In view of the above prior art, the present invention supplies oil from the outer peripheral side in the vicinity of the bearing in the middle part of the shaft member to the inner hollow part, and an oil seal disposed on the axially outer side of the bearing may be attached. It is an object of the present invention to provide a lubricating structure for a shaft member that has an oil passage structure that is easy and prevents oil from leaking from the oil seal to the outside and enables lubrication of the inner hollow portion of the shaft member.

  In order to solve the above-mentioned problem, the invention according to claim 1 is characterized in that at least an axially outer side of the bearing is provided on an inner peripheral surface of a bearing opening of a case that rotatably supports a shaft member via a bearing. One annular oil seal is inserted through the shaft member, and the case-side oil passage for supplying oil has an oil passage opening on the inner peripheral surface between the bearing and the annular oil seal. In a lubricating structure of a shaft member, in which a shaft member-side oil hole that is drilled in a bearing opening and supplies oil from the outer peripheral side to the inner hollow portion of the shaft member is formed in a coaxial member, the axial direction of the annular oil seal The shaft member lubrication structure is characterized in that an annular labyrinth seal is provided by inserting the shaft member inside and outside the oil passage opening in the axial direction.

  According to a second aspect of the present invention, in the lubricating structure for a shaft member according to the first aspect, a seal portion is provided between the inner race and the outer race of the bearing, and a gap between the seal portion and the annular labyrinth seal is provided. However, it is characterized in that it forms an oil flow path portion that connects the case side oil passage and the shaft member side oil hole.

  According to a third aspect of the present invention, in the lubricating structure for a shaft member according to the second aspect, the bearing opening of the case opens between the annular oil seal and the annular labyrinth seal, An oil relief passage leading to is provided.

  According to a fourth aspect of the present invention, in the lubricating structure for a shaft member according to the third aspect, the annular labyrinth seal is provided with radially extending radial ribs on the outer surface in the axial direction. .

  According to a fifth aspect of the present invention, in the lubricating structure for a shaft member according to any one of the second to fourth aspects, the annular labyrinth seal has a plurality of annular ribs directed radially inward at an inner peripheral edge thereof. It is characterized by having.

  According to a sixth aspect of the present invention, in the lubricating structure for a shaft member according to any one of the second to fifth aspects, the shaft member includes the inner hollow portion and a shaft member side oil hole. And a cylindrical collar member that is externally fitted to the coaxial main body and on which the annular oil seal and the annular labyrinth seal are sheathed, and the cylindrical collar member has an inner end in the axial direction of the inner race of the bearing. A radially inner circumferential portion extending from the notched groove to the shaft-side oil hole is provided with a radial notched groove at the axially inner end while being in contact with the axially outer end surface Is provided.

  According to the lubricating structure of the shaft member of the first aspect of the present invention, the oil in the inner peripheral surface of the bearing opening that flows from the case-side oil passage to the shaft-member-side oil hole is axially separated by the annular labyrinth seal and the annular oil seal. In addition, it is possible to eliminate the structure in which the oil pressure is applied between the double oil seals and the oil pressure is applied. Therefore, the oil can be supplied to the inner hollow portion of the shaft member by flowing the oil into the shaft member side oil hole while preventing the oil from leaking to the outer side in the axial direction of the annular oil seal.

  According to the invention of claim 2, in addition to the effect of the invention of claim 1, it is possible to prevent oil leakage from the oil flow path portion to the bearing side, and to guide the oil more reliably to the shaft member side oil hole. .

  According to the invention of claim 3, in addition to the effect of the invention of claim 2, even if there is oil leaking outward from the annular labyrinth seal, the leaked oil is sealed by the annular oil seal outside in the axial direction, It can be returned to the case from the escape passage.

  According to the invention of claim 4, in addition to the effect of the invention of claim 3, when the annular oil seal is press-fitted into the bearing opening of the case, the radial direction is provided between the annular oil seal and the annular labyrinth seal by the radial ribs. It is possible to press-fit while ensuring a clearance between the annular oil seal and improve the mounting performance of the annular oil seal, and an oil relief space can be formed between the annular oil seal and the annular labyrinth seal. The flow of is improved.

  According to the invention of claim 5, in addition to the effect of the invention of any one of claims 2 to 4, an annular labyrinth seal can be configured and provided with a simple structure.

  According to the invention of claim 6, in addition to the effect of the invention of any one of claims 2 to 5, when the annular oil seal and the annular labyrinth seal are externally mounted on the cylindrical collar member of the shaft member, An oil passage from the oil passage portion to the shaft member side oil hole can be formed with a simple shape.

1 is a right side view of a partially omitted internal combustion engine in which a multi-stage transmission using a lubricating structure for a shaft member according to an embodiment of the present invention is incorporated. FIG. 2 is a cross-sectional development view of the multi-stage transmission of the internal combustion engine, taken along the line II-II in FIG. 1. It is sectional drawing (sectional drawing by the III-III arrow in FIG. 5, FIG. 6) which shows a counter gear shaft and the structure around it. FIG. 8 is another cross-sectional view (a cross-sectional view taken along arrows IV-IV in FIGS. 5 and 6) showing the counter gear shaft and the structure around it. It is sectional drawing by the VV arrow in FIG. 3, FIG. It is sectional drawing by the VI-VI arrow view in FIG. 3, FIG. It is a disassembled perspective view of a shift rod and a lost motion mechanism. It is a disassembled perspective view of the state which assembled | attached the lost motion mechanism with the shift rod, and a cam rod. It is a disassembled perspective view of a part of a counter gear shaft, a pin member, and a spring. FIG. 10 is a left side view of the counter gear shaft as viewed in the direction of arrow X in FIG. 9. It is a disassembled perspective view of a rocking claw member, a spindle pin, a pin member, and a spring. It is a perspective view which shows the state which assembled | attached a part of speed-change drive mechanism and the engagement means to the counter gear shaft. FIG. 13 is a perspective view showing a state in which one bearing collar member is packaged on the counter gear shaft in the state shown in FIG. 12. It is explanatory drawing which shows 1 state of the process to shift up. It is a top view of a lower engine case. It is the left side view. FIG. 17 is an enlarged cross-sectional view of the vicinity of the bearing on the left side of the counter gear shaft, as viewed in the direction of arrows XVII-XVII in FIG. 16. It is a decomposition | disassembly expanded sectional view of the bearing vicinity of the left side of the counter gear shaft. It is a disassembled expanded sectional view of an annular oil seal, an annular labyrinth seal, and a cylindrical collar member. It is sectional drawing to which the principal part of FIG. 17 which shows the lubricating structure of a counter gear shaft was expanded.

Hereinafter, an embodiment according to the present invention will be described with reference to FIGS.
The multi-stage transmission 10 according to the present embodiment is configured to be incorporated in an internal combustion engine E mounted on a motorcycle (not shown).
FIG. 1 is a right side view of the internal combustion engine E shown in a state of being mounted on a motorcycle (not shown), and FIG. 2 is a cross-sectional development view of the multi-stage transmission 10 (II-II arrow in FIG. 1). As shown in FIGS. 1 and 2, the multi-stage transmission 10 is provided in an engine case 1 that is shared with the internal combustion engine E.

In the description of the present specification and the claims, the directions such as front, rear, left, right, up and down are the directions of the vehicle (motorcycle) in the state shown in FIG. 1 in which the internal combustion engine according to this embodiment is attached to a motorcycle (not shown). In FIG. 1, the right side in the figure is the front side of the vehicle, the upper side in the figure is the upper side of the vehicle, the other side in the figure is the left side of the vehicle, and the front side in the figure is the right side of the vehicle.
Hereinafter, in the drawings, arrow FR indicates the front of the vehicle, LH indicates the left side of the vehicle, RH indicates the right side of the vehicle, and UP indicates the upper side of the vehicle.

As shown in FIG. 1 which is a right side view of the engine case 1, the engine case 1 is formed by combining the upper engine case 1U and the lower engine case 1L which are divided vertically with a crankshaft 6 directed in the horizontal direction as a boundary. The engine case 1 is integrally formed with a transmission chamber 2, and the main gear shaft 11 and the counter gear shaft 12 of the multi-stage transmission 10 are parallel to each other in the horizontal direction in the transmission chamber 2. It is pivotally supported.
The upper engine case 1U and the lower engine case 1L are united by supporting the crankshaft 6 and the counter gear shaft 12 at the same height as the crankshaft 6 at a high position in the transmission chamber 2 so as to sandwich from above and below. .

  As shown in FIG. 2, a transmission chamber 2 is formed in the rear half of the combined engine case 1, and the engine case 1 supports the left side portions of the main gear shaft 11 and the counter gear shaft 12 in the transmission chamber 2. A large opening is formed on the right side, and the bearing cover member 8 covers the opening of the transmission chamber, and the bearing cover member 8 forming a part of the engine case covers the right side portions of the main gear shaft 11 and the counter gear shaft 12. Pivot.

The main gear shaft 11 is rotatably supported on the side wall of the lower engine case 1L and the bearing lid member 8 via bearings 3L and 3R, and passes through the right bearing 3R and protrudes from the transmission chamber 2 to the right end portion. A multi-plate friction clutch 5 is provided.
On the left side of the friction clutch 5, a primary driven gear 4 to which the rotation of the crankshaft 6 is transmitted is rotatably supported by the main gear shaft 11.
The rotation of the crankshaft 6 (see FIG. 1) of the internal combustion engine E is transmitted from the primary driven gear 4 to the main gear shaft 11 via the engaged friction clutch 5.

As shown in FIG. 2, the main gear shaft 11 has a hollow cylindrical shape, and the hollow is composed of a long large-diameter hole portion 11a having a relatively large inner diameter and a small-diameter hole portion 11b having a slightly reduced diameter on the right side. The long push rod 15l is inserted into the large-diameter hole 11a, the short push rod 15s is slidably inserted into the small-diameter hole 11b, and the right end 15lr of the long push rod 15l is inserted into the small-diameter hole 11b. The three balls 16 are sandwiched between the left end of the short push rod 15s.
The ball 16 has an outer diameter in which three small diameter holes 11b enter the same position in the axial direction, and the right end portion 15lr of the long push rod 15l and the left end portion of the short push rod 15s have an annular shape on the opposite end surfaces. A shallow annular groove is formed on each of the three balls 16 so that the three balls 16 can be stably held.

The left end portion of the long push rod 15l passes through the lower engine case 1L to the left and is fitted to the piston 17p of the clutch hydraulic actuator 17.
On the other hand, the right end portion of the short push rod 15s protrudes rightward from the main gear shaft 11 and abuts against the central portion of the pressure plate 5p of the friction clutch 5.

Therefore, when the clutch hydraulic actuator 17 is actuated and the piston 17p pushes the long push rod 15l to the right, the short push rod 15s is pushed through the ball 16, and the pressure plate 5p is made elastic by the clutch spring 5s. Accordingly, the friction clutch 5 engaged with the elastic force of the clutch spring 5s can be disengaged by moving to the right.
The three balls 16 serve as thrust bearings and do not transmit the rotation of the short push rod 15s to the long push rod 15l.

  The counter gear shaft 12 is formed in a hollow cylindrical shape having an inner hollow portion 12i, and the left side portion thereof is pivotally supported via a bearing 7L sandwiched between both side walls of the upper engine case 1R and the lower engine case 1L. The right end is pivotally supported by the bearing lid member 8 via the bearing 7R.

The main gear shaft 11 includes a drive transmission gear m group between the left and right bearings 3 </ b> L and 3 </ b> R so as to be rotatable integrally with the main gear shaft 11.
A first drive speed change gear m1 is formed integrally with the main gear shaft 11 along the right bearing 3R, and a spline formed between the first drive speed change gear m1 of the main gear shaft 11 and the left bearing 3L is shifted from right to left. The second, third, fourth, fifth, and sixth drive transmission gears m2, m3, m4, m5, and m6, whose diameters are sequentially increased, are spline-fitted.

On the other hand, on the counter gear shaft 12, a group of driven transmission gears n is rotatably supported via an annular bearing collar member 13 between the left and right bearings 7L and 7R (see FIGS. 3 and 4). .
In the counter gear shaft 12, as shown in FIGS. 3 and 4, the right end bearing collar member 13 is provided through a collar member 14R interposed on the left side of the right bearing 7R and the right side of the left bearing 7L. Between the leftmost bearing collar member 13 packaged through the mounted collar member 14L, five bearing collar members 13 are packaged at equal intervals, and a total of seven bearing collar members 13 are adjacent to each other. 13, 1st, 2nd, 3rd, 4th, 5th, 6th driven transmission gears n1, n2, n3, n4, n5, n6 with the diameter decreasing sequentially from right to left so as to straddle between 13 and 13 Is rotatably supported.

  The first, second, third, fourth, fifth, and sixth drive transmission gears m1, m2, m3, m4, m5, and m6 that rotate integrally with the main gear shaft 11 are rotatable about the counter gear shaft 12. The first, second, third, fourth, fifth, and sixth driven transmission gears n1, n2, n3, n4, n5, and n6 are always meshed with each other.

The meshing of the first drive transmission gear m1 and the first driven transmission gear n1 constitutes the first speed with the largest reduction ratio, and the meshing of the sixth drive transmission gear m6 and the sixth driven transmission gear n6 has the smallest reduction ratio. Sixth speed is configured, and during that period, the reduction gear ratio is gradually decreased to form second speed, third speed, fourth speed, and fifth speed.
The counter gear shaft 12 has odd-numbered gears (first, third, and fifth driven transmission gears n1, n3, and n5) with odd-numbered gears and even-numbered gears (second, fourth, and fourth) with even-numbered gears. 6 driven transmission gears n2, n4, n6) are alternately arranged.

  A counter gear shaft 12 having a coaxial cylindrical hollow cylindrical inner hollow portion 12i is incorporated so that engagement means 20 which can be engaged with each driven transmission gear n is described later, and engagement means 20 is described later. A total of eight cam rods C (Cao, Cao, Cae, Cae, Cbo, Cbo, Cbe, Cbe), each of which is one component of each type, is the inner circumference of the inner hollow portion 12i of the counter gear shaft 12. It is fitted in a cam guide groove 12g, which will be described later, formed on the surface, and is provided so as to be movable in the axial direction.

  A shift rod 51, which is one component of the speed change drive mechanism 50 that drives the cam rod C to change the speed, is inserted into the hollow center shaft of the counter gear shaft 12, and the shift rod 51 moves in the axial direction as a lost motion mechanism. The cam rod C is moved in the axial direction in conjunction with each other via 52 and 53.

A mechanism for moving the shift rod 51 in the axial direction is provided in the bearing lid member 8.
The movement of the shift rod 51 in the axial direction links the cam rod C in the axial direction via the lost motion mechanisms 52 and 53, and the movement of the cam rod C is engaged with each driven transmission gear by the engaging means 20 incorporated in the counter gear shaft 12. Shifting is performed by selectively engaging n with the counter gear shaft 12.

The engaging means 20 provided on the counter gear shaft 12 and selectively engaging the counter gear shaft 12 and each driven transmission gear n will be described below.
As shown in FIG. 7, the shift rod 51 of the speed change drive mechanism 50 has a cylindrical bar shape, and outer peripheral recesses 51 a and 51 b formed by reducing the diameter in two left and right axial directions have a predetermined length. Is formed.
The right end of the shift rod 51 is a male screw end portion 51bb formed with a male screw, and a hexagonal nut portion 51c is formed in front of the male screw end portion 51bb.

The lost motion mechanisms 52 and 53 are assembled corresponding to the left and right outer peripheral recesses 51a and 51b of the shift rod 51, respectively.
The left and right lost motion mechanisms 52 and 53 have the same structure and are arranged so as to be bilaterally symmetrical.

  The left lost motion mechanism 52 has a spring holder 52h into which the shift rod 51 is slidably inserted and is configured by connecting the long holder 52hl and the short holder 52hs, and the inner peripheral surface corresponds to the outer peripheral recess 51a of the shift rod 51. An inner peripheral recess 52ha is formed.

  When the shift rod 51 is passed through the spring holder 52h and the spring holder 52h is positioned in the outer peripheral recess 51a, the inner peripheral recess 52ha of the spring holder 52h and the outer peripheral recess 51a of the shift rod 51 constitute a common space. To do.

A pair of left and right cotters 52c and 52c, which are spring receivers, are fitted to face each other so as to straddle both spaces of the inner peripheral recess 52ha of the spring holder 52h and the outer peripheral recess 51a of the shift rod 51, and shift between the both cotters 52c and 52c A compression coil spring 52s wound around the rod 51 is interposed to urge both the cotters 52c and 52c in a separating direction.
The cotter 52c has a hollow disk shape in which the inner diameter of the inner peripheral recess 52ha of the spring holder 52h is the outer diameter and the outer diameter of the outer peripheral recess 51a of the shift rod 51 is the inner diameter, and is divided in half for assembly. Yes.

The right lost motion mechanism 53 (spring holder 53h, long holder 53hl, short holder 53hs, inner peripheral recess 53ha, cotter 53c, compression coil spring 53s) has the same structure and is disposed in the outer peripheral recess 51b of the shift rod 51. The
Therefore, when the shift rod 51 moves in the axial direction, the spring holders 52h, 53h move in the axial direction via the compression coil springs 52s, 53s of the left and right lost motion mechanisms 52, 53.

  As shown in FIG. 8, there are eight cam rods C (Cao, Cao, Cao, Cao, C) on the outer peripheral surfaces of the spring holders 52h, 53h of the lost motion mechanisms 52, 53 attached to the left and right outer peripheral recesses 51a, 51b of the shift rod 51. Cae, Cae, Cbo, Cbo, Cbe, and Cbe) are at the radiation positions and come into contact with each other.

The cam rod C is a prismatic rod-like member having a rectangular cross section and extending in the axial direction. The outer peripheral side opposite to the inner peripheral side contacting the spring holders 52h, 53h forms a cam surface, and the cam surface Grooves v are formed at the required three locations, and a pair of locking claws p that locks either one of the spring holders 52h and 53h from the left and right protrude from the inner peripheral side surface.
Since the cam rod C is a rectangular prismatic member having a simple cross section and a generally simple outer shape, the cam rod C can be easily manufactured.

  Cam grooves v1, v3, and v5 have odd-numbered cam rods Cao and Cbo formed at three positions corresponding to odd-numbered gears (first, third, and fifth driven gears n1, n3, and n5). There are two types of rotation (rotation direction in which force is applied from the driven transmission gear n to the counter gear shaft 12 during acceleration) and reverse rotation (rotation direction in which force is applied from the driven transmission gear n to the counter gear shaft 12 during deceleration). One forward rotation odd-stage cam rod Cao has an engaging claw p that engages with the right spring holder 53h on the inner peripheral side, and the other reverse rotation odd-stage cam rod Cbo has a left spring holder 52h on the inner peripheral side. It has the latching claw p latched to.

  Similarly, cam grooves v2, v4, v6 are even-numbered cam rods Cae formed at three positions corresponding to even-numbered gears (second, fourth, sixth driven transmission gears n2, n4, n6). , Cbe are of two types, one for forward rotation and one for reverse rotation. One forward rotation even-numbered cam rod Cae has a locking claw p that locks the left spring holder 52h on the inner peripheral side surface, The reverse rotation even-stage cam rod Cbe has a locking claw p that locks to the right spring holder 53h on the inner peripheral side surface.

  Accordingly, when the shift rod 51 is moved in the axial direction, the positive rotation odd-numbered cam rod Cao and the reverse-rotation even-numbered cam rod Cbe are interlocked with the spring holder 53h via the compression coil spring 53s of the lost motion mechanism 53 on the right side. Then, the reverse rotation odd stage cam rod Cbo and the forward rotation even stage cam rod Cae are interlocked in the axial direction together with the spring holder 52h via the coil spring 52s of the left lost motion mechanism 52.

  As shown in FIG. 8, a cylindrical shift rod operating element 55 is attached to the right end portion on the right side of the nut portion 51c of the shift rod 51 via a ball bearing 56 fitted inside.

  Two ball bearings 56 are connected in the axial direction. The ball bearing 56 is inserted into the right end portion on the right side of the nut portion 51c of the shift rod 51 and is engaged with the nut portion 51c by a nut 57 screwed into the male screw end portion 51bb. It is sandwiched and fastened.

Therefore, the shift rod operator 55 holds the right end portion of the shift rod 51 rotatably.
A pin hole 55h pierced in the diametrical direction is formed in a cylindrical portion extending to the right side from the nut 57 to which the shift rod operating element 55 is screwed, and the shift pin 58 passes through the pin hole 55h.

  The shift pin 58 passes through the shift rod operating element 55 and protrudes only to one side (see FIG. 2). As shown in FIG. 8, the protruding end portion is a shift guide groove G of the shift drum 67 described later. A cylindrical engaging portion 58a that slidably engages with the small rod portion 58c passing through the shift rod operating element 55, and a sliding portion 58b having a rectangular parallelepiped shape is formed between the engaging portion 58a. ing.

As shown in FIGS. 1 and 2, the bearing lid member 8 that supports the right end portions of the main gear shaft 11 and the counter gear shaft 12 via bearings 3R and 7R is provided coaxially with the counter gear shaft 12 on the right side. A cylindrical guide portion 8g is formed so as to protrude.
The cylindrical guide portion 8g includes a circular hole 8gh through which the shift rod operating element 55 slides, and a lower portion thereof is cut obliquely downward to form a guide long hole 8gl that is elongated in the axial direction.

A support shaft 65 is implanted obliquely below the cylindrical guide portion 8g of the bearing lid member 8, and a cylindrical shift drum 67 is rotatably supported on the support shaft 65 via a bearing 66.
The shift rod operating element 55 is inserted into the circular hole 8gh of the cylindrical guide part 8g, and at the same time, the sliding part 58b having a rectangular parallelepiped shape of the shift pin 58 passing through the shift rod operating element 55 is inserted into the guide long hole of the cylindrical guide part 8g. 8g is slidably inserted, and the engaging portion 58a at the end of the shift pin 58 is slidably engaged with the shift guide groove G of the shift drum 67.
The power of a speed change actuator (not shown) such as a speed change motor (or the operating force of manual shift operation) is transmitted to a gear 67g formed on the side edge of the shift drum 67 to sequentially shift the shift drum 67. Rotate to position.

  The shift rod moving mechanism (shift drum 67, shift pin 58, shift rod operating element 55) that moves the shift rod 51 in the axial direction via the shift pin 58 by the rotation of the shift drum 67 is a friction at the right end of the main gear shaft 11. It is compactly arranged between the clutch 5 and the driven transmission gear n on the counter gear shaft 12 (see FIG. 2).

The shift guide groove G of the shift drum 67 is formed so as to form a spiral over two or more rounds on the outer peripheral surface of the drum, and each speed change from the first speed to the sixth speed at every predetermined rotation angle (for example, 150 degrees) therebetween. The step positions are formed in order.
There is a neutral N position before the first gear.

  The rotation of the shift drum 67 is guided by the shift pin 58 having the engagement portion 58a engaged with the shift guide groove G in the guide long hole 8gl of the cylindrical guide portion 8g of the bearing cover member 8, and is translated in the axial direction. The shift rod 51 is moved in the axial direction via the shift rod operator 55, and the movement of the shift rod 51 is caused by the eight cam rods Cao, Cao, Cae, Cae of the engagement means 20 via the lost motion mechanisms 52, 53. , Cbo, Cbo, Cbe, Cbe are linked.

The shift rod 51 to which the lost motion mechanisms 52 and 53 are assembled is inserted into the inner hollow portion 12i of the counter gear shaft 12 and disposed on the central shaft.
The hollow cylindrical counter gear shaft 12 has an inner diameter substantially equal to the outer diameter of the spring holders 52h and 53h of the lost motion mechanisms 52 and 53, and the spring holders 52h and 53h attached to the shift rod 51 are slidably inserted. To do.

Then, eight cam guide grooves 12g having a rectangular cross section are formed extending in the axial direction at eight radial positions on the inner peripheral surface of the inner hollow portion 12i of the counter gear shaft 12 (FIG. 10). reference).
The eight cam rods Cao, Cao, Cae, Cae, Cbo, Cbo, Cbe, and Cbe are slidably fitted into the corresponding cam guide grooves 12g in the arrangement shown in FIG.
The same type of cam rod C is disposed at a symmetrical position with respect to the central axis.
The cam guide groove 12g, which serves as a detent for the cam member C with respect to the counter gear shaft 12, has a simple U-shaped cross section and can be easily machined.

  The cam guide groove 12g has a depth equal to the radial width of the cam rod C. Therefore, the cam surface which is the outer peripheral side surface of the cam rod C is in sliding contact with the bottom surface of the cam guide groove 12g, and the inner peripheral side surface is substantially the same as the hollow inner peripheral surface. A locking claw p which forms a surface and comes into contact with the outer peripheral surface of the spring holders 52h and 53h and protrudes from the inner peripheral side surface grips either of the spring holders 52h and 53h from both sides.

As shown in FIG. 9, the counter gear shaft 12 having a hollow cylindrical shape has an outer diameter reduced on both the left and right sides of the central cylindrical portion 12 a on which the driven transmission gear n is supported via a bearing collar member 13. A left cylindrical portion 12b and a right cylindrical portion 12c are formed.
A bearing 7R is fitted to the right cylindrical portion 12c of the counter gear shaft 12 via a washer 14R (see FIGS. 3 and 4).

  As shown in FIGS. 9 and 18, the left cylindrical portion 12b of the counter gear shaft 12 has a shaft end portion protruding outward (left side) from the journal portion 12j to which the inner race 7Li of the bearing 7L is fitted. A male screw 12e formed at the outer end, a spline groove 12s formed inside the male screw 12e, and an outer peripheral groove 12f formed in the circumferential direction at the boundary between the male screw 12e of the spline groove 12s.

And, between the journal portion 12j and the spline groove 12s, an oil introduction hole ("shaft member side oil hole" of the present invention) 12x communicating the outer peripheral side of the counter gear shaft 12 and the inner hollow portion 12i is provided in the circumferential direction. Multiple perforations.
The left end opening of the inner hollow portion 12i of the counter gear shaft 12 is closed by a plug member 39.
The assembly structure of the output sprocket 32 to be spline fitted into the spline groove 12s and the lubrication structure using the oil introduction hole 12x will be described later.

The inside hollow portion 12i of the counter gear shaft 12 has a small inner diameter surface in which the cam guide groove 12g is formed equal to the outer diameter of the spring holders 52h and 53h, and inner diameters on both axial sides of the same small diameter inner peripheral surface. A large-diameter inner peripheral surface that forms substantially the same peripheral surface as the bottom surface of the cam guide groove 12g is formed (see FIGS. 3 and 4).
About half of the shift rod operating element 55 is inserted inside the enlarged inner diameter part on the right side.

  Thus, the shift rod 51, the lost motion mechanisms 52 and 53, and the eight cam rods Cao, Cao, Cae, Cae, Cbo, Cbo, Cbe, Cbe, and Cbe are incorporated into the inner hollow portion 12i of the counter gear shaft 12. When all of these rotate together and the shift rod 51 moves in the axial direction, the reverse rotation odd stage cam rod Cbo and the forward rotation even stage cam rod Cae are moved via the coil spring 52s of the left lost motion mechanism 52. Linked in the axial direction, the positive rotation odd-numbered cam rod Cao and the reverse rotation even-numbered cam rod Cbe linked in the axial direction via the coil spring 53s of the right lost motion mechanism 53.

  The central cylindrical portion 12a on which the driven transmission gear n is pivotally supported through the bearing collar member 13 of the counter gear shaft 12 has a large outer diameter and is configured to be thick as shown in FIG. Narrow circumferential groove 12cv that goes around in the circumferential direction on the outer circumference of the first, second, third, fourth, fifth, and sixth driven transmission gears n1, n2, n3, n4, n5, n6 In addition, six axial grooves 12av are formed at equal intervals in the axial direction, and four axial grooves 12av oriented in the axial direction are formed at equal intervals in the circumferential direction.

  Further, on the outer peripheral portion of the central cylindrical portion 12a of the counter gear shaft 12, four portions defined by four axial grooves 12av are adjacent to each other in the circumferential direction. A long rectangular recess 12p that is extended equally between the grooves 12av and 12av in the left and right direction, and a short length in which the groove width of the circumferential groove 12cv is equally expanded in the left and right directions in a part between the adjacent axial grooves 12av and 12av. Rectangular recesses 12q are alternately formed in the axial direction.

Spring receiving portions 12d and 12d, which are long oval in the axial direction and slightly recessed over the circumferential groove 12cv, are formed at two locations apart in the circumferential direction on the bottom surface of the long rectangular recess 12p.
Further, a pin hole 12h is formed in the radial direction up to the cam guide groove 12g on the circumferential groove 12cv at a thick portion between the short rectangular recess 12q and the axial groove 12av.

That is, the pin hole 12h is drilled in the radial direction of the cam guide groove 12g engraved at eight locations in the circumferential direction from the inner peripheral surface of the inner hollow portion 12i of the counter gear shaft 12.
Four pin holes 12h are formed on each circumferential groove 12cv.

The spring receiving portion 12d is provided with a compression spring 22 wound in an elliptical shape with its end fitted.
A pin member 23 is slidably inserted into the pin hole 12h.
The cam guide groove 12g communicating with the pin hole 12h is smaller than the outer diameter width of the pin member 23.
Therefore, the pin member 23 that advances and retreats through the pin hole 12h does not fall into the cam guide groove 12g, so that the engagement means 20 can be easily assembled to the counter gear shaft 12.
However, although the pin hole 12h does not reach the inner peripheral end of the cam guide groove 12g, the pin hole is overlapped with the cam guide groove 12g until the pin member 23 can reach the bottom of the cam groove v of the cam rod C.

Since the cam rod C is slidably fitted in the cam guide groove 12g, the pin member 23 fitted in the pin hole 12h comes into contact with the cam surface of the corresponding cam rod C at the center end, and the cam rod C moves. When the cam groove v corresponds to the pin hole 12h, the pin member 23 falls into the cam groove v, and when the slidable contact surface other than the cam groove v corresponds, the pin member rides on the slidable contact surface and moves forward and backward by the movement of the cam rod C.
The advancement and retraction of the pin member 23 in the pin hole 12h causes the distal end portion of the pin member 23 to protrude outward from the bottom surface of the circumferential groove 12cv.

The swinging claw member R is formed in the circumferential groove 12cv that communicates between the long rectangular recess 12p and the short rectangular recess 12q formed on the outer peripheral portion of the central cylindrical portion 12a of the counter gear shaft 12 having the above-described structure. Is embedded, and a support pin 26 is embedded in the axial groove 12av to pivotally support the swing claw member R.
FIG. 12 shows a state where all the swinging claw members R are assembled in this way.

  In the exploded perspective view of FIG. 11, the circumferential grooves 12cv, the long rectangular recesses 12p, and the short rectangular recesses 12q corresponding to the odd-stage gears (first, third, and fifth driven transmission gears n1, n3, and n5) are embedded. Four swinging claw members R, and circumferential grooves 12cv and long rectangular recesses 12p corresponding to even-numbered even-numbered gears (second, fourth, sixth driven transmission gears n2, n4, n6), The four swinging claw members R embedded in the short rectangular recess 12q are illustrated in a posture maintaining the relative angular positional relationship with each other, and in addition, a support pin that pivotally supports each swinging claw member R. 26 and a compression spring 22 and a pin member 23 acting on each swing claw member R are shown.

  The swinging claw members R are all of the same shape, have a substantially arc shape when viewed in the axial direction, and the outer peripheral portion of the through hole through which the support shaft pin 26 penetrates in the center lacks the bearing recess Rd. A wide rectangular engagement claw Rp is formed on one side of the bearing recess Rd so as to be swingably fitted to the long rectangular recess 12p. A pin hole is formed on the other side. A narrow pin receiving portion Rr that slidably fits in the circumferential groove 12cv formed with 12h extends, and an end of the pin receiving portion Rr reaches a short rectangular recess 12q to form a wide end Rq that is widened. Yes.

In the swing claw member R, the pin receiving portion Rr is fitted in the circumferential groove 12cv in which the pin hole 12h is formed, and one engaging claw portion Rp is fitted in the long rectangular recess 12p and the bearing recess Rd is formed. The other wide end Rq is fitted in the short rectangular recess 12q, matching the axial groove 12av.
Then, the support pin 26 is fitted into the matched bearing recess Rd and the axial groove 12av.

  The swinging claw member R is formed symmetrically with respect to the circumferential groove 12cv to be fitted, and one wide rectangular engagement claw Rp is heavier than the other pin receiving part Rr and the wide end Rq, When the pin 26 is pivotally supported and rotates together with the counter gear shaft 12, the swinging claw member R swings so that the engaging claw Rp acts as a weight against the centrifugal force and protrudes in the centrifugal direction.

The swinging claw member R is formed such that the pin receiving portion Rr is narrower than the engaging claw Rp side on the opposite side with respect to the swinging center.
Further, since the pin receiving portion Rr only needs to have a width sufficient to receive the pin member 23, the swinging claw member R can be formed in a small size, and the other engaging claw portion Rp can be swung by the centrifugal force. The movement can be facilitated.

  Since the swinging claw members R adjacent to each other in the circumferential direction are assembled to the counter gear shaft 12 in a symmetrical attitude, the engaging claw portions Rp and Rp facing each other with a predetermined interval are common long rectangular recesses 12p. The other wide end Rq adjacent to each other is fitted into a common short rectangular recess 12q.

  A compression spring 22 supported at one end by a spring receiving portion 12d of the counter gear shaft 12 is interposed inside the engaging claw portion Rp of the swing claw member R, and is inserted into the pin hole 12h inside the pin receiving portion Rr. The pin member 23 is interposed between the cam rod C and the pin member 23.

  In this way, the swinging claw member R is pivotally supported by the support shaft pin 26 and embedded in the long rectangular recess 12p, the short rectangular recess 12q, and the circumferential groove 12cv of the counter gear shaft 12. The engaging claw portion Rp is urged outward by the compression spring 22, and the other pin receiving portion Rr is pressed by the advancement and retraction of the pin member 23, so that the oscillating claw member resists the urging force of the compression spring 22. R swings.

When the pin member 23 advances in the centrifugal direction and swings the swinging claw member R, the swinging claw member R has the engagement claw portion Rp submerged in the long rectangular recess 12p and the central cylinder of the counter gear shaft 12 There is nothing that protrudes outward from the outer peripheral surface of the portion 12a.
When the pin member 23 is retracted, the engaging claw Rp biased by the compression spring 22 protrudes outward from the outer peripheral surface of the central cylindrical portion 12a of the counter gear shaft 12, and can be engaged with the driven transmission gear n. To do.

  Four swinging claw members R corresponding to odd-numbered gears (first, third, and fifth driven transmission gears n1, n3, and n5) and even-numbered gears (second, fourth, and sixth driven gears) The four swinging claw members R corresponding to the transmission gears n2, n4, and n6) are in a relative angular position relationship that is rotated 90 degrees around the axis.

  The four swinging claw members R corresponding to the odd-numbered gears (first, third, and fifth driven transmission gears n1, n3, and n5) are brought into contact with each other in the forward rotation direction of the gears, and each of the odd-numbered driven gears n1. , N3, n5 and the counter gear shaft 12 are engaged with each other so as to rotate in synchronization with each other, and the odd-numbered driven gears n1, n3 are in contact with each other in the reverse rotation direction of the gear. , N5 and counter gear shaft 12 are provided with a pair of counter-rotating odd-numbered engaging members Rbo that are engaged so as to rotate in synchronization with each other at symmetrical positions.

  Similarly, the four swinging claw members R corresponding to the even-numbered gears (second, fourth, and sixth driven transmission gears n2, n4, and n6) are brought into contact with each other in the forward rotation direction of the gears, and each even-numbered gear is driven. A forward rotation even-numbered-stage swing claw member Rae engaged so that the transmission gears n2, n4, n6 and the counter gear shaft 12 rotate in synchronization with each other, and the even-numbered driven gears in contact with each other in the reverse rotation direction of the gear. A pair of counter-rotating even-numbered engaging members Rbe that are engaged so that n2, n4, and n6 and the counter gear shaft 12 rotate synchronously are provided in pairs at symmetrical positions.

The forward rotation odd-stage swinging claw member Rao is swung by the pin member 23 that moves forward and backward by the movement of the forward-rotation odd-stage cam rod Cao, and the reverse-rotation odd-stage engagement member Rbo is moved by the reverse-rotation odd-stage cam rod Cbo. It swings by the pin member 23 that advances and retreats by
Similarly, the forward rotating even-stage swinging claw member Rae is swung by the pin member 23 that moves forward and backward by the movement of the forward-rotating even-numbered cam rod Cae, and the reverse-rotating even-numbered engaging member Rbe is the reverse-rotating even-numbered cam rod. The pin member 23 is moved back and forth by the movement of Cbe to swing.

  When the engaging means 20 is incorporated in the counter gear shaft 12, as shown in FIG. 13, first, the right end bearing collar member 13 is externally mounted on the outer peripheral end of the central cylindrical portion 12a, and the inner shaft of the bearing collar member 13 is installed. The right end engaging means 20 is incorporated so as to fit one end of the support pin 26 into the direction groove 12av, and the next bearing collar member 13 is covered so as to cover the other end of the support pin 26, and the driven transmission gear After incorporating n, assembling the next-stage engaging means 20 in the same manner as in the previous stage is sequentially repeated, and finally, the leftmost bearing collar member 13 is packaged and the process ends.

As shown in FIG. 13, the bearing collar member 13 is packaged in an axial position other than the long rectangular recess 12p and the short rectangular recess 12q of the central cylindrical portion 12a, and is continuously embedded in a line in the axial groove 12av. The support pin 26 and the swinging claw member R are prevented from falling off.
Since the support pin 26 embedded in the axial groove 12av of the central cylindrical portion 12a of the counter gear shaft 12 is embedded at a depth in contact with the outer peripheral surface of the central cylindrical portion 12a, when the bearing collar member 13 is sheathed. It is fixed without play.

Seven bearing collar members 13 are mounted on the counter gear shaft 12 at equal intervals, and the driven transmission gear n is rotatably supported so as to straddle between the adjacent bearing collar members 13 and 13.
Each driven transmission gear n has a notch formed in the left and right inner periphery (the left and right periphery of the inner peripheral surface), and a thin annular protrusion 30 is formed between the left and right notches. The left and right bearing collar members 13 and 13 are slidably engaged with the notches so as to be sandwiched (see FIGS. 3 and 4).

On the protrusion 30 on the inner peripheral surface of each driven transmission gear n, six engagement convex portions 31 are formed at equal intervals in the circumferential direction (see FIGS. 5 and 6).
The engaging convex portion 31 has a thin arc shape when viewed from the side (the axial direction shown in FIGS. 5 and 6), and both end surfaces in the circumferential direction engage with the engaging claw portion Rp of the swing claw member R. An engagement surface is formed.

  The forward rotation odd-numbered swinging claw member Rao (forward rotation even-numbered swinging claw member Rae) and the reverse rotation odd-numbered step engagement member Rbo (reverse rotation even-numbered step engagement member Rbe) Rp and Rp are extended, and the positive rotation odd-numbered swinging claw member Rao (positive rotation even-numbered swinging claw member Rae) is an engagement convex portion in the positive rotation direction of the driven transmission gear n (and the counter gear shaft 12). The reverse rotation odd-numbered engagement member Rbo (reverse rotation even-numbered engagement member Rbe) contacts and engages the engagement convex portion 31 in the reverse rotation direction of the driven transmission gear n. To do.

  It should be noted that the forward rotation odd-numbered swinging claw member Rao (forward rotation even-numbered swinging claw member Rae) is not engaged in the reverse rotation direction of the driven transmission gear n even if the engagement claw portion Rp protrudes to the outside. In addition, the reverse rotation odd-numbered engagement member Rbo (reverse rotation even-numbered engagement member Rbe) is not engaged in the forward rotation direction of the driven transmission gear n even if the engagement claw Rp protrudes outward.

Thus, with the six driven transmission gears n assembled to the counter gear shaft 12, the counter gear shaft 12 is rotatably supported on the side wall of the engine case 1 and the bearing lid member 8 via the left and right bearings 7L and 7R. As a result, the six driven transmission gears n and the seven bearing collar members 13 are alternately combined and sandwiched from the left and right to perform axial positioning.
The bearing collar member 13 supports the axial force of each driven transmission gear n and can receive axial positioning and thrust force.

  When the cam rod C is in the neutral position, all the driven transmission gears n have the pin members 23 protruding from the movement positions of the cam rods C of the corresponding engaging means 20 so that the pin receiving portions Rr of the swinging claw member R are moved from the inside. In the disengaged state in which the push-up engagement claw Rp is retracted inward, it rotates freely with respect to the counter gear shaft 12.

  On the other hand, the pin member 23 enters the cam groove v by the movement position of the engagement means 20 other than the neutral position of the cam rod C, the swing claw member R swings, and the engagement claw portion Rp protrudes outward. Then, the engagement convex portion 31 of the corresponding driven transmission gear n comes into contact with the engagement claw portion Rp, and the rotation of the driven transmission gear n is transmitted to the counter gear shaft 12, or the counter gear shaft 12 Is transmitted to the driven transmission gear n.

  In the shift drive mechanism 50, the shift drum 67 is rotated by a predetermined amount by driving a shift actuator or by a manual shift operation, and the shift rod 51 is rotated via a shift pin 58 fitted in the shift guide groove G. Is moved by a predetermined amount in the axial direction, and the eight cam rods Cao, Cao, Cae, Cae, Cbo, Cbo, Cbe, Cbe of the engaging means 20 are interlocked via the lost motion mechanisms 52, 53.

  As the cam rod C moves in the axial direction, the pin member 23 slidably in contact with the cam surface of the cam rod C moves into and out of the cam groove v to move forward and backward, swinging the swinging claw member R, and driven gear The shift is performed by releasing the engagement with n and changing the driven transmission gear n that engages with the counter gear shaft 12 by engaging with another driven transmission gear n.

  The power of the internal combustion engine is transmitted to the main gear shaft 11 via the friction clutch 5, and the first, second, third, fourth, fifth and sixth drive transmission gears m1, m2, m3, m4, m5 , M6 are integrally rotated, and the first, second, third, fourth, fifth, and sixth driven transmission gears n1, n2, n3, n4, n5, and n6, which are always meshed with them, are respectively connected. It is rotating at the rotation speed.

  3 to 6 show the first speed state. In FIG. 5, the first driven transmission gear n1 rotates in the direction of the arrow, and in FIG. 6, the second driven transmission gear n2 rotates in the direction of the arrow. The second driven transmission gear n2 rotates at a higher speed than the first driven transmission gear n1.

  Only the pin member 23 of the engaging means 20 corresponding to the first driven transmission gear n1 is in the cam groove v1 of the positive rotation odd-numbered cam rod Cao (see FIG. 3). The odd-numbered swinging claw member Rao protrudes outward from the engaging claw Rp, and the engaging convex portion 31 of the rotating first driven transmission gear n1 becomes the engaging claw Rp of the positive rotation odd-numbered swinging claw member Rao. When engaged (see FIG. 5), the counter gear shaft 12 is rotated together with the first driven transmission gear n1 at the same rotational speed as the first driven transmission gear n1.

In this first speed state, in the second driven transmission gear n2, the pin member 23 of the corresponding engagement means 20 protrudes from the cam groove v2 of the even-numbered cam rods Cae and Cbe (see FIG. 4), and the engagement means Since the 20 even-numbered swinging claw members Rae and Rbe have retracted the engaging claw Rp inside, they are idle.
The other third, fourth, fifth, and sixth driven transmission gears n3, n4, n5, and n6 are similarly idle (see FIGS. 3 and 4).

  Here, when there is a manual operation of the shift select lever to shift to the second speed and the shift drum 67 rotates and the shift rod 51 starts to move rightward in the axial direction, the coil springs 52s of the lost motion mechanisms 52 and 53 are moved. , 53s try to move the eight cam rods Cao, Cao, Cae, Cae, Cbo, Cbo, Cbe, Cbe to the right in the axial direction.

Hereinafter, one state in the process of shifting up from the first speed state to the second speed state in which the reduction ratio is one step smaller at the time of acceleration by driving the internal combustion engine will be described with reference to FIG.
14A is a cross-sectional view in which the gears and the like in FIG. 3 in the state are omitted, FIG. 14B is a cross-sectional view in which the gears and the like in FIG. 4 in the state are omitted, and FIG. FIGS. 14A and 14B are cross-sectional views taken along the line c-c (cross-sectional view of the first driven transmission gear n1), and FIG. 14D is a cross-sectional view of FIG. 14A and FIG. It is -d arrow sectional drawing (sectional drawing of the 2nd driven transmission gear n2).

  As shown in FIG. 14 (d), the pin member 23 enters the cam groove v2 by the movement of the positive rotation even-numbered cam rod Cae, so that the positive rotation even-numbered swing pawl member corresponding to the second driven transmission gear n2 is obtained. Rae is swung by the urging force of the compression spring 22 and the centrifugal force of the engaging claw Rp to project the engaging claw Rp outward, and can be engaged with the second driven transmission gear n2. The first driven transmission gear n1 The engaging convex portion 31 of the second driven transmission gear n2 that rotates at a higher speed than the counter gear shaft 12 that rotates with the counter gear shaft 12 catches up with the engaging claw portion Rp that protrudes to the outside of the forward rotation even-numbered swing claw member Rae.

FIG. 14 shows a state immediately before the engagement convex portion 31 of the second driven transmission gear n2 catches up with the engagement claw portion Rp protruding outward of the forward rotation even-stage swing claw member Rae. In FIG. 14 (d), the engagement convex portion 31 of the first driven transmission gear n1 is engaged with the positive rotation odd-numbered swinging claw member Rao at the same time as shown in FIG. 14 (d). Immediately before the mating convex portion 31 catches up with the engaging claw portion Rp projecting outside the forward rotation even-stage swinging claw member Rae.
In FIG. 14 (c), lattice hatching is applied to the swinging claw member R and the engaging projection 31 which are effectively transmitting power.

  From the state shown in FIG. 14, when the engagement convex portion 31 of the second driven transmission gear n2 catches up with the engagement claw portion Rp projecting outside the forward rotation even-stage swing claw member Rae, the second rotation speed is increased. The counter gear shaft 12 starts to rotate at the same rotational speed as that of the second driven transmission gear n2 by the two driven transmission gears n2, and the engagement convex portion 31 of the first driven transmission gear n1 engages with the positive rotation odd-numbered stage swing claw member Rao. The pawl portion Rp is released, and the actual upshift from the first speed to the second speed is executed.

  When the engagement claw Rp of the positive rotation odd-numbered swinging claw member Rao is separated from the engagement convex portion 31 of the first driven transmission gear n1, the frictional resistance for fixing the positive rotation odd-numbered swinging claw member Rao is eliminated. The positive rotation odd-numbered cam rod Cao urged by the coil spring 53s of the lost motion mechanism 53 moves backward and the pin member 23 that has entered the cam groove v1 comes out and swings in the positive rotation odd-numbered step. The claw member Rao is swung and the engagement claw portion Rp is retracted inward.

  As described above, when shifting up from the first-speed acceleration state to the second-speed state in which the reduction ratio is one step smaller, the engagement convex portion 31 of the first driven transmission gear n1 is moved in the positive rotation odd-numbered swing claw member Rao. The engaging convex portion of the second driven transmission gear n2 that rotates at a higher speed while the counter gear shaft 12 rotates at the same speed as the first driven transmission gear n1 by contacting and engaging with the engaging claw Rp. Since the counter 31 catches up with the engagement claw Rp of the forward rotation even-numbered swing claw member Rae and rotates the counter gear shaft 12 at a higher speed together with the second driven transmission gear n2, the first driven transmission gear is shifted. Since the engaging claw Rp of the positive rotation odd-numbered swinging claw member Rao is separated from the engaging convex portion 31 of n1 naturally and the engagement is smoothly released, a force is not required for releasing the engagement smoothly. Operates and can perform smooth upshifts.

  Similarly, each shift-up from 2nd to 3rd, 3rd to 4th, 4th to 5th, and 5th to 6th is performed with the driven transmission gear n engaged with the swinging claw member R. Since the driven transmission gear n with a reduction ratio of one step is engaged with the swinging claw member R and shifted up, no force is required to release the engagement and the clutch is not required for shifting. In addition, there is no loss in the switching time at the time of upshifting, there is no loss of driving force, and the shift shock is small, so that smooth upshifting can be performed.

  Similarly, in the downshift, the driven claw member R is engaged with the driven transmission gear n whose gear ratio is one step larger while the driven transmission gear n is engaged with the swing claw member R, and the downshift is performed. Therefore, no force is required for disengagement, it operates smoothly and does not require a clutch for shifting, there is no loss in switching time at the time of downshifting, there is no loss of driving force, and the shift shock is small Smooth downshifting can be done.

The counter gear shaft 12 accommodates shift rods 51, eight cam rods C, lost motion mechanisms 52, 53 and the like in the inner hollow portion 12i, and it is necessary to supply lubricating oil to these sliding members. As shown in FIG. 2, since the output sprocket 32 is provided at the left end portion of the counter gear shaft 12 and part of the speed change drive mechanism 50 is provided at the right end portion, oil cannot be introduced from both ends.
Therefore, the counter gear shaft 12 of the present embodiment employs a lubrication structure in which an oil introduction hole 12x leading from the outer peripheral side to the inner hollow portion 12i is formed on the left side of the shaft support portion by the left bearing 7L, and oil is introduced from the outer peripheral side. doing.

Hereinafter, a lubricating structure for supplying oil to the inner hollow portion 12i of the counter gear shaft 12 will be described with reference to FIGS.
As shown in the top view and the left side view of the lower engine case 1L in FIGS. 15 and 16, the outer race 7Lo of the bearing 7L is provided in the bearing opening 1e that fits and supports the bearing 7L of the lower engine case 1L. A bearing support portion 1eb to be supported and a seal support portion 1es outside the bearing support portion 1eb in the axial direction are provided.
Inner peripheral grooves 1bv and 1sv are formed on the outer sides in the axial direction of the inner peripheral surfaces of the bearing support portion 1eb and the seal support portion 1es.
Further, an inner peripheral protrusion 1sp is formed at the inner end in the axial direction of the inner peripheral surface of the seal support portion 1es (see FIG. 18).

  The upper engine case 1R is also provided with a bearing opening 1e that fits and supports the bearing 7L, a bearing support 1eb that supports the outer race 7Lo of the bearing 7L, and an axially outer seal support of the bearing support 1eb. 1 es is provided, and inner circumferential grooves 1 bv, 1 sv, and inner circumferential ridge 1 sp are also formed.

  15 and 16, a main oil passage Y is formed in the lower engine case 1L, and a branch oil passage branched from the main oil passage Y ("case side oil passage" of the present invention) y Extends into the bearing opening 1e, and an oil passage opening 1x is formed on the inner circumferential surface of the bearing support 1eb of the bearing opening 1e on the axially outer side of the outer race 7Lo of the bearing 7L (FIG. 17, FIG. 18).

  On the other hand, the counter gear shaft 12 is in a state where the bearing 7L is fitted to the journal portion 12j with the washer 14L sandwiched between the journal portion 12j and the central cylindrical portion 12a having the maximum outer diameter (see FIG. 17). When the outer race 7Lo is positioned and fitted to the bearing support portion 1eb by the retaining ring 45 fitted in the inner circumferential groove 1ev, as shown in FIG. 18, the inner circumferential surface of the bearing opening 1e and the counter gear shaft An annular space 47 is formed between the outer peripheral surface of 12 and an oil passage opening 1x of the branch oil passage y of the lower engine case 1L and an oil introduction hole 12x of the counter gear shaft 12 open into the annular space 47. .

As shown in FIGS. 17 and 18, a cylindrical collar member 33 is formed on the outer peripheral surface of the counter gear shaft 12 (the “shaft body” of the present invention) corresponding to the seal support portion 1 es of the bearing opening 1 e. A shaft member 9 that is externally fitted is formed.
The cylindrical collar member 33 has the axially inner end portion 33a abutting against the inner race 7Li of the bearing 7L, and the annular notch 33c of the axially outer end portion 33b is engaged with the disc spring 34. The output sprocket 32 is pressed against the sprocket groove 12s of the counter gear shaft 12 and spline-fitted.

  A pair of half cotters 35 and 35 are fitted to the outer peripheral groove 12f of the counter gear shaft 12 so as to be pressed from the left side on the counter gear shaft 12 with respect to the output sprocket 32 spline-fitted in the sprocket groove 12s. An annular retainer 36 is externally fitted to a pair of half cotters 35, 35 that form an annular shape.

The annular retainer 36 is composed of an outer peripheral surface and an outer peripheral wall facing the outer peripheral surface and outer surface of the half cotters 35 and 35 that are combined in an annular shape, and the outer periphery of the annular retainer 36 comes into contact with the outer surface of the half cotters 35 and 35. The wall covers the outer peripheral surfaces of the half cotters 35 and 35 and holds the half cotters 35 and 35.
Then, a bag-like nut member 37 is screwed into the outermost male screw 12e of the counter gear shaft 12, and the annular retainer 36 is sandwiched between the half cotter 35 and fixed.

The output sprocket 32 that is spline-fitted to the counter gear shaft 12 in this way is in contact with the annular retainer 36 and is restricted from moving in the axial direction, and between the cylindrical collar member 33 that is in contact with the inner race 7Li of the bearing 7L. It is elastically pressed against the half cotter 35 by a disc spring 34 interposed therebetween.
Accordingly, the force component acting in the axial direction acting on the output sprocket 32 when the chain 38 (see FIG. 2) is wound is absorbed by the disc spring 34, and the output sprocket 32 is always positioned within the required axial range to be stable. Power transmission is possible.
The counter gear shaft 12 is an output shaft. A chain 38 is wound around an output sprocket 32 fitted with a spline, and power is transmitted to the rear wheel side through the chain 38, so that a motorcycle (not shown) travels.

On the inner peripheral surface of the seal support portion 1es of the bearing opening 1e, it is positioned on the outer side in the axial direction by a retaining ring 46 fitted in the inner peripheral groove 1sv between the outer peripheral side of the cylindrical collar member 33, An annular oil seal 40 is fitted through the cylindrical collar member 33.
As shown in FIG. 19, the annular oil seal 40 has a large-diameter outer annular seal portion piece 40a in which a rubber member is baked on an annular metal piece bent into an L-shaped cross section between a cylindrical portion and an inner flange portion, The rubber member of the outer annular seal piece 40a is formed with an annular elastic lip portion 40b with the inner peripheral edge portion of the inner flange portion extending slightly inward in the axial direction toward the central axis, and a cylindrical collar member 33 is formed. It is pressed against the outer peripheral side. A ring spring 40c is externally fitted near the tip of the annular elastic lip 40b.

Further, the inner peripheral surface of the seal support portion 1es of the bearing opening 1e is adjacent to the inner side in the axial direction of the annular oil seal 40 and between the outer peripheral side of the cylindrical collar member 33 by the inner peripheral protrusion 1sp. The annular labyrinth seal 41 is fitted into the cylindrical collar member 33, which is positioned toward the inner side in the direction.
As shown in FIG. 19, the annular labyrinth seal 41 has an outer peripheral edge 41 a that is press-contacted to the inner peripheral surface of the seal support portion 1 es and the inner peripheral ridge 1 sp. The two ribs 41b are provided. There may be three or more annular ribs 41b.

The inner diameter dsl of the annular rib 41b is set to a tolerance larger than the outer diameter d1 of the cylindrical collar member 33 so as to have a slight gap with the cylindrical collar member 33.
Therefore, the labyrinth seal is configured with a simple structure in which a plurality of annular ribs 41b are provided on the inner peripheral edge of a simple annular member.
Further, as shown in FIG. 19, the annular labyrinth seal 41 is provided with radially extending radial ribs 41d on the axially outer side surface 41c of the outer peripheral edge portion 41a, between which a partial arcuate recess 41e and It has become.

The cylindrical collar member 33 is provided with a taper surface 33t on the outer peripheral side at the axially inner end portion 33a, and is provided with a plurality of, for example, four, radial cutout grooves 33x dispersed in the circumferential direction. Yes.
In addition, as shown in FIG. 17, the inner periphery from the axial inner end 33 a to the oil introduction hole 12 x of the counter gear shaft 12 with the cylindrical collar member 33 fitted to the counter gear shaft 12. The surface is expanded in diameter to form an expanded inner peripheral portion 33xi.

On the other hand, the bearing 7L is a one-side sealed bearing, and a bearing seal portion (the “sealing portion” of the present invention) 7Ls is provided on the left side in the axial direction between the inner race 7Li and the outer race 7Lo.
Since the oil passage opening 1x of the branch oil passage y is located between the bearing 7L and the annular oil seal 40 and the annular labyrinth seal 41, the gap 1ex between the bearing seal portion 7Ls and the annular labyrinth seal 41 is cylindrical. The collar member 33 communicates with the oil introduction hole 12x of the counter gear shaft 12 through a notch groove 33x in the radial direction and an enlarged inner peripheral portion 33xi.

Therefore, a gap 1ex between the bearing seal portion 7Ls and the annular labyrinth seal 41 is formed between the inner peripheral surface of the bearing opening 1e and the counter gear shaft 12 and the cylindrical collar member 33 forming the shaft member 9, so that the branch oil passage An oil passage portion connecting the oil passage opening 1x of y and the oil introduction hole 12x is formed.
Even if the cylindrical collar member 33 is fitted over the oil introduction hole 1x of the counter gear shaft 12, the oil channel portion has the simple structure of the notch groove 33x and the enlarged inner peripheral portion 33xi. To the oil introduction hole 12x.

Therefore, the oil in the inner peripheral surface of the bearing opening 1e flowing from the oil passage opening 1x of the branch oil passage y to the oil introduction hole 12x passes through the gap 1ex between the bearing seal portion 7Ls and the annular labyrinth seal 41, and is further cylindrical. Since the oil flows into the oil introduction hole 12x of the counter gear shaft 12 via the radial cutout groove 33x and the enlarged diameter inner peripheral portion 33xi, the oil is more reliably prevented from leaking to the bearing 7L side. In addition to being supplied to the oil introduction hole 12x, the oil is double-sealed by the annular labyrinth seal 41 and the annular oil seal 40 with respect to the outside in the axial direction, and oil leakage to the outside in the axial direction is effective. To be prevented.
Also, as described in the prior art, oil pressure is applied between the oil seals by using the oil flow path portion between the double oil seals mounted on the counter gear shaft 12, and the outer oil seal is moved outward in the axial direction. Oil leakage can be avoided.

Further, as shown in FIG. 17, between the annular labyrinth seal 41 and the annular oil seal 40, the oil drilled in the bearing opening 1e is formed on the inner peripheral surface of the seal support portion 1es of the bearing opening 1e. One end of the escape passage 1z is provided so as to open, and the other end of the oil release passage 1z is opened in the engine case 1.
Therefore, even if oil leaks axially outward from the annular labyrinth seal 41, hydraulic pressure is not substantially applied to the annular oil seal 40, so that leakage to the outside of the annular oil seal 40 can be prevented.

  Even if the annular labyrinth seal 41 and the annular oil seal 40 are close to each other, the oil relief space is provided by the partial arcuate recess 41e between the radial ribs 41d on the axially outer side surface 41c of the outer peripheral edge 41a of the annular labyrinth seal 41. 41f is formed, and one end side of the oil relief passage 1z is opened without any trouble by the oil relief space 41f, and the leaked oil can be recirculated into the engine case 1.

The maximum outer diameter of the annular oil seal 40 is the outer diameter formed by the outer peripheral surface of the rubber member of the cylindrical portion of the outer annular seal piece 40a, which is somewhat larger than the inner diameter of the seal support portion 1es of the bearing opening 1e, but changes elastically. To do.
The minimum inner diameter when the external force of the annular oil seal 40 is not applied is the inner diameter ds formed by the annular elastic lip 40b (see FIG. 19). Note that the inner diameter of the oil seal 40 changes elastically.
The maximum outer diameter of the annular labyrinth seal 41 is somewhat larger than the inner diameter of the seal support portion 1es of the bearing opening 1e, but changes elastically.

On the other hand, the cylindrical collar member 33 into which the inner peripheral surface of the oil seal 40 is fitted has an outer diameter d1 and is larger than the inner diameter ds of the inner elastic lip 42i as shown in FIG. The tip of the inner end 33a is tapered to form a tapered surface 33t, and the outer diameter d2 of the tip edge of the tapered surface 33t is smaller than the inner diameter ds of the inner elastic lip 42i.
Further, the outer diameter d1 of the cylindrical collar member 33 is smaller than the inner diameter dsl of the annular labyrinth seal 41 as described above.
That is, d2 <ds <d1, d1 <dsl.

As shown in FIG. 20, an annular oil seal 40 is inserted together with an annular labyrinth seal 41 into the seal support portion 1es of the bearing opening 1e of the engine case 1, and is fitted into a predetermined position on the inner peripheral surface of the seal support portion 1es. When positioned by the retaining ring 46 fitted in the inner circumferential groove 1sv, the outer peripheral edge portion 41a of the annular labyrinth seal 41 comes into pressure contact with the inner circumferential protrusion 1ep.
Thus, the cylindrical collar member 33 is inserted between the inner peripheral surface of the oil seal 40 and the annular labyrinth seal 41 fitted in the bearing opening 1 e and the outer peripheral surface of the counter gear shaft 12.

Since the cylindrical collar member 33 is fitted into the annular oil seal 40 from the axially inner end 33a side (tapered surface 33t side) of the outer diameter d2 smaller than the annular oil seal inner diameter ds, the tip of the axially inner end portion 33a is inserted. First, the taper surface 33t comes into contact with the annular elastic lip portion 40b to expand its diameter, and the annular elastic lip portion 40b is elastically pressed against the outer peripheral surface of the cylindrical collar member 33.
Next, the inclined tapered surface 33t at the tip of the axially inner end portion 33e is easily inserted into the annular labyrinth seal 41 having an inner diameter dsl larger than the outer diameter d1 of the cylindrical collar member 33.

  As described above, when the annular oil seal 40 is press-fitted into the seal support portion 1es of the bearing opening 1e of the fuselage case 1, the radial ribs 41d provide an axial clearance between the annular oil seal 40 and the annular labyrinth seal 41. The oil relief space 41f can be formed between the annular oil seal 40 and the annular labyrinth seal 41 while improving the attachment property of the annular oil seal 41.

As described above, when the cylindrical collar member 33 is fitted in contact with the inner race 7Li of the bearing 7L, the counter gear shaft 12 and the cylindrical collar member 33 are integrated into the annular oil seal 40 as the integral shaft member 9. An oil flow path portion provided with a double seal of the annular labyrinth seal 41 and pivotally supported by the body case 1 and formed by a gap 1ex between the bearing seal portion 7Ls and the annular labyrinth seal 41 from the oil passage opening 1x of the branch oil passage y. Further, the oil passage extending to the oil introduction hole 12x of the counter gear shaft 12 through the notch groove 33x in the radial direction of the cylindrical collar member 33 and the enlarged diameter inner peripheral portion 33xi is formed in a simple cylindrical shape The collar member 33 is formed.
In this way, the lubricating structure of this embodiment that supplies the inner hollow portion 12i of the counter gear shaft 12 is configured.

  That is, in the lubricating structure of the present embodiment, as indicated by an arrow in FIG. 20, the oil that has branched into the branch oil passage y branched from the main oil passage Y of the lower engine case 1L is the bearing support portion of the bearing opening 1e. The oil passage opening 1x opened on the inner peripheral surface of 1eb flows into the oil passage portion formed by the gap 1ex between the bearing seal portion 7Ls and the annular labyrinth seal 41, and the radial cutout groove 33x of the cylindrical collar member 33 The oil is introduced into the oil introduction hole 12x of the counter gear shaft 12 through the enlarged diameter inner peripheral portion 33xi and supplied to the inner hollow portion 12i of the counter gear shaft 12 through the oil introduction hole 12x.

Here, a lubricating structure in the counter gear shaft 12 of the multi-stage transmission 10 of the present embodiment will be described.
As shown in the left side view of the counter gear shaft 12 in FIG. 10, the radial inner surface of the counter gear shaft 12 has four radial positions where the eight cam guide grooves 12g are arranged every other two. An axial oil supply groove 12y is cut in parallel to the cam guide groove 12g (see FIG. 5 and FIG. 6).

Each of the axial oil supply grooves 12y communicates with a radial oil supply hole 12z that is drilled in the radial direction at an axial position where the required pin member 23 exists, and the radial oil supply hole 12z is connected to the axial oil supply groove 12y and the swinging claw member. It communicates with the circumferential groove 12cv in which R is fitted.
In addition, each axial direction oil supply groove | channel 12y does not connect to the radial direction oil supply hole 12z drilled by the adjacent axial direction position among the axial direction positions in which the pin member 23 is located, but the radial direction of every other axial position It communicates with the oil supply hole 12z.

  That is, of the four axial oil supply grooves 12y, one opposing two axial oil supply grooves 12y correspond to odd-numbered gears (first, third, and fifth driven transmission gears n1, n3, and n5). It communicates with the radial oil supply hole 12z that opens in the circumferential groove 12cv in which the pin member 23 is located (see FIG. 11), and the other two opposing axial oil supply grooves 12y are even gears (second and fourth gears). , Communicated with the radial oil supply hole 12z opened in the circumferential groove 12cv in which the pin member 23 corresponding to the sixth driven transmission gear n2, n4, n6) is located (see FIG. 12).

  The oil introduced into the hollow end portion of the counter gear shaft 12 through the oil introduction hole 12x is guided in the axial direction along the inner peripheral surface of the counter gear shaft 12 by the axial oil supply groove 12y. Even with a small oil supply actuator with a small oil path resistance, the entire engagement switching mechanism (engagement means 20 such as rocking claw member R, pin member 23, compression spring 22, and cam rod C) is smoothly lubricated and sufficiently lubricated. can do.

  Four axial oil supply grooves 12y are formed, and each axial oil supply groove 12y does not communicate with the radial oil supply holes 12z drilled at the adjacent axial position among the axial positions where the pin member 23 is located. Oil supplied from one end of the axial oil supply groove 12y can be passed to the other end without much lowering the oil pressure, and can be supplied substantially evenly to the engagement switching mechanisms arranged in the axial direction.

Hereinafter, the characteristics of the lubricating structure of the shaft member of this embodiment will be described collectively.
That is, one annular oil seal 40 is provided on the inner peripheral surface of the bearing opening 1e of the engine case 1 that rotatably supports the counter gear shaft 12 forming the shaft member 9 via the bearing 7L, and on the outer side in the axial direction from the bearing 7L. Is inserted through the shaft member 9, and the branch oil passage y on the engine case 1 side for supplying lubricating oil has an oil passage opening 1x on the inner peripheral surface between the bearing 7L and the annular oil seal 40. In the lubricating structure of the shaft member, which is formed in the bearing opening 1e so as to have an oil introduction hole 12x for supplying oil from the outer peripheral side to the inner hollow portion 12i of the shaft member 9, An annular labyrinth seal 41 is provided by inserting the shaft member 9 inside the seal 40 in the axial direction and outside the oil passage opening 1x in the axial direction.

  Therefore, the oil in the inner peripheral surface of the bearing opening 1e flowing from the branch oil passage y on the engine case 1 side to the oil introduction hole 12x is hardly leaked to the outside in the axial direction by the annular labyrinth seal 41 and the annular oil seal 40. The structure between the double oil seals as described above can be an oil flow path portion and not a structure in which hydraulic pressure is applied. Accordingly, the oil can be supplied to the inner hollow portion 12 i of the shaft member 9 by flowing the oil into the oil introduction hole 12 x while preventing the oil from leaking to the outer side in the axial direction of the annular oil seal 40.

A bearing seal portion 7Ls is provided between the inner race 7Li and the outer race 7Lo of the bearing 7L, and a gap 1ex between the bearing seal portion 7Ls and the annular labyrinth seal 41 is connected to the branch oil passage y and the oil on the engine case 1 side. An oil passage portion connecting the introduction hole 12x is formed.
Therefore, it is possible to prevent oil from leaking from the gap 1ex forming the oil flow path portion to the bearing 7L, and to more reliably guide the oil to the oil introduction hole 12x.

In addition, an oil relief passage 1 z communicating with the engine case 1 is provided between the annular oil seal 40 and the annular labyrinth seal 41 in the bearing opening 1 e of the engine case 1.
Therefore, even if there is oil leaking outward from the annular labyrinth seal 41, the leaked oil can be sealed by the annular oil seal 40 on the outer side in the axial direction and returned to the engine case 1 from the oil escape passage 1z.

The annular labyrinth seal 41 is provided with radial ribs 41d extending radially on the axially outer side surface 41c.
Therefore, when the annular oil seal 10 is press-fitted into the bearing opening 1 e of the engine case 1, the annular oil seal 40 can be press-fitted between the annular oil seal 40 and the annular labyrinth seal 41 while securing an axial clearance by the radial rib 41 d. The oil relief space 41f can be formed between the annular oil seal 40 and the annular labyrinth seal 41 while improving the attachment of the annular oil seal 40, and the oil flow to the oil relief passage 1z is good. Become.

Further, the annular labyrinth seal 41 has a plurality of annular ribs 41b facing inward in the radial direction at the inner peripheral edge thereof.
Therefore, the annular labyrinth seal 41 can be configured and provided with a simple structure.

The shaft member 9 is externally fitted to the counter gear shaft 12 serving as a shaft body including the inner hollow portion 12i and the oil introduction hole 12x, and the counter gear shaft 12, and the annular oil seal 40 and the annular labyrinth seal 41 are externally provided. And a cylindrical collar member 33. The cylindrical collar member 33 has an axially inner end 33a abutting against an axially outer end surface of the inner race 7Li of the bearing 7L, and an axially inner end 33a. A notch groove 33x in the radial direction is provided, and an enlarged inner peripheral portion 33xi from the notch groove 33x to the oil introduction hole 12x is provided.
Therefore, even when the annular oil seal 40 and the annular labyrinth seal 41 are mounted on the cylindrical collar member 33 of the shaft member 9, the gap between the bearing seal portion 7 </ b> Ls and the annular labyrinth seal 41 that form an oil flow path is simple. An oil passage connecting 1ex and the oil introduction hole 12x can be formed.

In the present embodiment as described above, the main gear shaft 11 and the counter gear shaft 12 which are rotatably mounted in the engine case 1 via the respective pairs of bearings 3L, 3R and 7L, 7R Each of the plurality of drive transmission gears m1 to m6 and the driven transmission gears n1 to n6 is pivotally supported in a constantly meshed state for each shift stage, and one of the drive transmission gears m1 to m6 is fixed to the main gear shaft 11 and the other driven gear An engagement switching mechanism for switching the engagement of the gear shaft 12 and each of the gears n1 to n6 for each gear between the transmission gears n1 to n6 and the counter gear shaft 12 is provided, and the engagement switching mechanism is driven by the transmission drive mechanism. A multi-stage transmission 10 that performs gear shifting,
The engagement switching mechanism is supported by an engagement projection 31 provided with engagement surfaces in the circumferential direction at a plurality of circumferential positions on the inner circumferential surface of each of the gears n1 to n6, and the counter gear shaft 12 and is pivotally supported. A swinging claw member R whose one end that moves engages and disengages with the engagement surface of the engagement convex portion 31, and a pin member 23 that contacts the other swinging end of the swinging claw member R from the inside in the radial direction The swinging claw member R is inserted into the cam guide groove 12g cut in the axial direction on the inner peripheral surface of the hollow portion of the counter gear shaft 12 so as to move in the axial direction and slide in contact with the pin member 23. A plurality of cam rods C that operate,
In the multi-stage transmission 10 in which the speed change drive mechanism includes a shift rod 51 that is inserted into the hollow central shaft of the counter gear shaft 12 inside the cam rod C and moves the cam rod C by moving in the axial direction.
On the inner peripheral surface of the bearing opening 1e of the engine case 1 that rotatably supports the counter gear shaft 12 that forms the shaft member 9 via the bearing 7L, one annular oil seal 40 is provided on the outer side in the axial direction from the bearing 7L. The branch oil passage y on the side of the engine case 1 that is inserted through the member 9 and supplies lubricating oil has an oil passage opening 1x on the inner peripheral surface between the bearing 7L and the annular oil seal 40. The shaft member 9 has an oil introduction hole 12x formed in the shaft opening 9 through which the oil introduction hole 12x is formed in the bearing opening 1e and supplies oil from the outer peripheral side to the inner hollow portion 12i of the shaft member 9. A multi-stage transmission 10 using a lubricating structure of a shaft member in which an axial labyrinth seal 41 is provided by inserting a shaft member 9 inside the seal 40 in the axial direction and outside the oil passage opening 1x is shown. ing.

According to the multi-stage transmission 10 shown in the present embodiment, the main gear shaft 11 and the counter gear shaft which are parallel to each other and are rotatably mounted in the engine case 1 via a pair of bearings 3L, 3R and 7L, 7R. 12, the plurality of drive transmission gears m1 to m6 and the driven transmission gears n1 to n6 are pivotally supported in a constantly meshed state at each shift stage, and the engagement switching mechanism is driven by the shift drive mechanism to perform a shift. In machine 10,
The oil in the inner peripheral surface of the bearing opening 1e that flows from the branch oil passage y on the engine case 1 side to the oil introduction hole 12x is prevented from leaking axially outward by the annular labyrinth seal 41 and the annular oil seal 40. The structure between the double oil seals becomes an oil flow path portion and the hydraulic pressure is not applied. Accordingly, the oil can be supplied to the inner hollow portion 12i of the shaft member 9 by flowing the oil into the oil introduction hole 12x while preventing the oil from leaking to the outer side in the axial direction of the annular oil seal 40, and the inner hollow portion 12i. The internal speed change drive mechanism and the engagement switching mechanism can be lubricated.

  In the multi-stage transmission 10 described above, the bearing seal portion 7Ls is provided between the inner race 7Li and the outer race 7Lo of the bearing 7L, and the clearance 1ex between the bearing seal portion 7Ls and the annular labyrinth seal 41 is an engine case. The oil flow path connecting the branch oil path y on the 1 side and the oil introduction hole 12x is formed, so oil leakage from the gap 1ex forming the oil flow path to the bearing 7L is prevented, and the oil is introduced more reliably. Oil can be directed to the holes 12x.

As mentioned above, although the lubricating structure of the shaft member which concerns on one Embodiment of this invention was demonstrated, of course, this invention includes the different aspect from the said embodiment within the range of the summary of each claim.
For example, the lubricating structure of the shaft member of the present invention is limited to the shaft member used in the multi-stage transmission incorporated in the internal combustion engine mounted on the motorcycle according to the embodiment as long as the shaft member has the configuration of claim 1. Not.

  E ... internal combustion engine, m1 to m6 ... first to sixth drive transmission gears, n1 to n6 ... first to sixth driven transmission gears, y ... branch oil passage ("case side oil passage" of the present invention), 1 ... Engine case, 1U ... Upper engine case, 1L ... Lower engine case, 1e ... Bearing opening, 1eb ... Bearing support, 1es ... Seal support, 1sp ... Inner peripheral ridge, 1ex ... Gap, 1x ... Oil passage opening DESCRIPTION OF SYMBOLS 1z ... Oil relief passage, 7L ... (left) bearing, 7Li ... Inner race, 7Lo ... Outer race, 7Ls ... Bearing seal part ("seal part" of this invention), 9 ... Shaft member, 10 ... Multi-stage transmission, 11 ... main gear shaft, 12 ... counter gear shaft, 12i ... inner hollow portion, 12x ... oil introduction hole ("shaft member side oil hole" of the present invention), 33 ... cylindrical collar member, 33a ... inner end portion in the axial direction, 33b: axially outer end portion, 33c: annular notch, 33t: tapered surface, 33 ... notch groove, 33xi ... expanded inner circumference, 40 ... annular oil seal, 41 ... annular labyrinth seal, 41a ... outer peripheral edge, 41b ... annular rib, 41c ... axial outer surface, 41d ... radial rib, 41e ... Partial arcuate recess, 41f ... oil relief space, 46 ... stop ring (of oil seal 40), 47 ... annular space

Claims (6)

On the inner peripheral surface of the bearing opening (1e) of the case (1) that rotatably supports the shaft member (9) via the bearing (7L), at least one annular member is provided on the outer side in the axial direction from the bearing (7L). An oil seal (40) is inserted through the shaft member (9),
The bearing opening (1e) is arranged such that a case-side oil passage (y) for supplying oil has an oil passage opening (1x) on the inner peripheral surface between the bearing (7L) and the annular oil seal (40). )
In the lubricating structure of the shaft member, the shaft member side oil hole (12x) for supplying oil from the outer peripheral side to the inner hollow portion (12i) of the shaft member (9) is formed in the coaxial member (9).
An annular labyrinth seal (41) is provided by inserting the shaft member (9) inside the annular oil seal (40) in the axial direction and outside the oil passage opening (1x) in the axial direction. A lubricating structure of the shaft member.   A seal portion (7Ls) is provided between the inner race (7Li) and the outer race (7Lo) of the bearing (7L), and a gap (1ex) between the seal portion (7Ls) and the annular labyrinth seal (41) is provided. 2. The shaft member lubricating structure according to claim 1, further comprising an oil passage portion connecting the case side oil passage (y) and the shaft member side oil hole (12 x). 3.   The bearing opening (1e) of the case (1) opens between the annular oil seal (40) and the annular labyrinth seal (41), and the oil relief passage (1z) communicates with the case (1). The shaft member lubricating structure according to claim 2, further comprising:   The lubricating structure for a shaft member according to claim 3, wherein the annular labyrinth seal (41) is provided with radially extending radial ribs (41d) on an axially outer surface (41c) thereof.   5. The annular labyrinth seal (41) according to any one of claims 2 to 4, wherein the annular labyrinth seal (41) has a plurality of radially-inward-facing annular ribs (41 b) at its inner peripheral edge. The lubricating structure of the shaft member as described.   The shaft member (9) is externally fitted to a shaft main body (12) having the inner hollow portion (12i) and a shaft member side oil hole (12x), and a coaxial main body (12), and the annular oil seal (40) And a cylindrical collar member (33) on which the annular labyrinth seal (41) is sheathed. The cylindrical collar member (33) has an inner end (33a) in the axial direction at the inner end of the bearing (7L). Abutting on the outer end surface in the axial direction of the race (7Li), the inner end portion (33a) in the axial direction is provided with a radial notch groove (33x), and the notch groove (33x) The shaft member lubricating structure according to any one of claims 2 to 5, further comprising an enlarged inner peripheral portion (33xi) extending to the shaft member side oil hole (12x).

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