JP2017223200A - Power transmission device and stator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power transmission device which can unfailingly inhibit wear of a pinion mechanism and a ring gear, and to provide a stator.SOLUTION: A driving pinion mechanism 110 includes: a pinion inner 111 which is provided so as to slide on an idle shaft 102 and so as not to rotate relative to the idle shaft 102; a pinion outer 112 which can move relative to the pinion inner 111 along an axial direction of the idle shaft 102 and engage with a ring gear 23; a pinion spring 117 which is provided between the idle shaft 102 and the pinion inner 111 and provides a biasing force to the pinion inner 111 to bias the pinion inner 111 to the ring gear 23 side; an outer flange part 123 which restricts movement of the pinion outer 112 in an opposite direction of the ring gear 23 relative to the pinion inner 111; and a wave washer 121 provided between the outer flange part 123 and the pinion outer 112.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a power transmission device and a starter.

For example, in a starter used for starting an engine of an automobile, a motor unit that generates a rotational force when energized is connected to a rotating shaft of the motor unit via a speed reduction mechanism, and rotates by receiving the rotating force of the rotating shaft. Output shaft (drive shaft), a pinion gear (pinion mechanism) that is externally fitted so as not to be movable relative to the output shaft and is slidable in the axial direction, and energizes and shuts off the motor unit, and the pinion gear on the ring gear side There is an electromagnetic switch (electromagnetic device) that pushes out the main structure.
In this type of starter, when the engine is started, a pinion gear is pushed out to the ring gear side by an electromagnetic switch, and meshed with the pinion gear and the engine ring gear. Then, the engine is started by transmitting the rotational force of the output shaft to the ring gear via the pinion gear.

By the way, when the pinion gear is pushed out to the ring gear side, the phase of the ring gear and the phase of the pinion gear may not match and may collide. When such a collision is repeated, the ring gear and the pinion gear may be worn. For this reason, the technique which provides a pinion spring between a drive shaft and a pinion gear is disclosed.
The pinion spring accumulates compressive stress in the axial direction according to the sliding movement of the pinion gear with respect to the drive shaft. For this reason, the impact at the time of meshing of a drive shaft and a pinion gear is relieved, and it becomes possible to suppress wear of a ring gear or a pinion gear.

JP 2009-138656 A

  By the way, in recent years, in order to improve the quietness of the vehicle and improve the fuel efficiency, an increasing number of vehicles have a so-called idle stop function that temporarily turns off the engine when the vehicle is temporarily stopped. In a vehicle having an idle stop function, the collision frequency between the ring gear and the pinion gear increases. For this reason, it is necessary to further alleviate the impact at the time of meshing between the drive shaft and the pinion gear and to suppress wear of the ring gear and the pinion gear.

  Accordingly, the present invention has been made in view of the above-described circumstances, and provides a power transmission device and a starter that can reliably suppress wear of a pinion mechanism and a ring gear.

  In order to solve the above-described problems, a power transmission device according to the present invention includes a power generation unit, a shaft that rotates around the central axis under the force of the power generation unit, and a rotation that receives rotation of the shaft. A pinion mechanism, wherein the pinion mechanism is slidable on the shaft and is non-rotatable relative to the shaft; and the shaft of the shaft with respect to the first pinion part. A second pinion portion movable along the axial direction and meshable with an external gear; and provided between the shaft and the first pinion portion, and a biasing force to the first pinion portion toward the external gear side An elastic member that biases the first pinion part and the second pinion part, and the second pinion part moves in the direction opposite to the external gear with respect to the first pinion part. Rule And a damper portion that is provided between the restriction portion and any one of the first pinion portion and the second pinion portion to relieve an impact at the time of collision between the other and the restriction portion, It is provided with.

  By comprising in this way, the impact at the time of meshing | engagement with an external gear and a 2nd pinion part can be absorbed by an elastic member, after absorbing by a damper part. That is, the impact at the time of meshing with the external gear and the second pinion portion can be reduced by the two members of the damper portion and the elastic member. For this reason, wear of the pinion mechanism can be reliably suppressed.

  In the power transmission device according to the present invention, the first pinion part is a cylindrical pinion inner fitted on the shaft, and the second pinion part is a pinion outer fitted on the pinion inner. The pinion inner is provided on the side opposite to the external gear, the restricting portion is provided, and the damper portion is provided between the restricting portion and the axial end of the pinion outer. Features.

  By constituting in this way, while being able to simplify the composition of the 1st pinion part and the 2nd pinion part, the shock at the time of the 1st pinion part and the 2nd pinion part colliding can be absorbed reliably by the damper part. . For this reason, wear of the pinion mechanism can be reliably suppressed.

  In the power transmission device according to the present invention, the elastic member is a coil spring, and the damper portion is a wave washer.

  By comprising in this way, the structure of an elastic member or a damper part can be simplified. Further, since the space for arranging the elastic member and the damper portion can be saved as much as possible, the pinion mechanism can be reduced in size.

  The power transmission device according to the present invention includes a transmission gear provided on the shaft so as to be slidable, extends in a direction parallel to the shaft, is rotatable about a central axis, and is interlocked with the sliding movement of the transmission gear. An idle shaft that is slidably movable in the central axis direction, and an idle gear that is provided on one axial end side of the idle shaft and meshes with the transmission gear, and the other axial end side of the idle shaft Further, the pinion mechanism is provided, and the idle shaft functions as the shaft.

  By comprising in this way, a pinion mechanism can be arrange | positioned in the position shifted | deviated from the shaft. For this reason, the freedom degree of the layout of a power transmission device can be raised. Further, since the so-called biaxial power transmission device provided with the idle shaft has a large inertia applied to the idle shaft, the above-described pinion mechanism can be preferably used.

  In the starter according to the present invention, the external gear is a ring gear connected to an engine, and the ring gear is driven by the pinion mechanism of the power transmission device described above.

  By comprising in this way, the starter which can suppress reliably wear of a pinion mechanism and a ring gear can be provided.

  According to the present invention, the impact at the time of engagement between the external gear and the second pinion portion can be absorbed by the elastic member after being absorbed by the damper portion. That is, the impact at the time of meshing with the external gear and the second pinion portion can be reduced by the two members of the damper portion and the elastic member. For this reason, wear of the pinion mechanism can be reliably suppressed.

It is sectional drawing of the starter in embodiment of this invention. It is an expanded sectional view of the idle gear unit in the embodiment of the present invention. It is explanatory drawing which shows operation | movement of the drive pinion mechanism in embodiment of this invention, Comprising: (a)-(c) shows the behavior in the middle of operation | movement of a drive pinion mechanism.

  Next, embodiments of the present invention will be described with reference to the drawings.

(Starter)
FIG. 1 is a cross-sectional view of the starter 1.
As shown in the figure, the starter 1 is for generating a rotational force necessary for starting an engine (not shown). The starter 1 includes a motor unit 3, a drive shaft 4 connected to one of the motor units 3 (left side in FIG. 1), a clutch mechanism 5 slidably provided on the drive shaft 4, and the drive shaft 4. The idle gear unit 100 that transmits the rotational force of the engine to the ring gear 23 of the engine (not shown), the switch unit 7 that opens and closes the power supply path to the motor unit 3, and the movable contact plate 8 of the switch unit 7 are moved along the axial direction And an electromagnetic device 9 for the purpose.

(Motor part)
The motor unit 3 is connected to the brushed DC motor 51 and the rotating shaft 52 of the brushed DC motor 51, and the planetary gear mechanism 2 as a reduction mechanism for transmitting the rotational force of the rotating shaft 52 to the drive shaft 4. It is comprised by.
The brushed DC motor 51 includes a substantially cylindrical motor yoke 53, and an armature 54 that is disposed on the radially inner side of the motor yoke 53 and is rotatable with respect to the motor yoke 53. A plurality (for example, six in the present embodiment) of permanent magnets 57 are provided on the inner peripheral surface of the motor yoke 53 so that the magnetic poles alternate in the circumferential direction.

At the other end (right side in FIG. 1) of the motor yoke 53, an end plate 55 for closing the opening 53a of the motor yoke 53 is provided. At the center in the radial direction of the end plate 55, a sliding bearing 56a and a thrust bearing 56b for rotatably supporting the other end of the rotating shaft 52 are provided.
The armature 54 includes an armature core 58 that is externally fitted and fixed at a position corresponding to the permanent magnet 57 of the rotating shaft 52, and the planetary gear mechanism 2 side of the armature core 58 of the rotating shaft 52 (in FIG. 1). And a commutator 61 that is externally fitted and fixed to the left side).

  The armature core 58 has a plurality of teeth (not shown) formed radially and a plurality of slots (not shown) formed between the teeth adjacent in the circumferential direction. A coil 59 is wound by, for example, wave winding between the slots spaced at a predetermined interval in the circumferential direction. The terminal portion of the coil 59 is drawn toward the commutator 61.

The commutator 61 is provided with a plurality of (for example, 26 in the present embodiment) segments 62 along the circumferential direction and at a predetermined interval so as to be electrically insulated from each other.
A riser 63 that is bent so as to be folded is provided at the end of each segment 62 on the armature core 58 side. A terminal part of a coil 59 wound around the armature core 58 is connected to the riser 63.

On the opposite side of the motor yoke 53 from the end plate 55, a bottomed cylindrical top plate 12 is provided. A planetary gear mechanism 2 as a first transmission gear is provided on the inner surface of the top plate 12 on the armature core 58 side.
The planetary gear mechanism 2 includes a sun gear 13 formed integrally with a rotating shaft 52, a plurality of planetary gears 14 that mesh with the sun gear 13 and revolve around the sun gear 13, and an annular inner gear provided on the outer peripheral side of the planetary gears 14. The tooth ring gear 15 is used.

  The internal ring gear 15 is integrally formed on the inner surface of the top plate 12 on the armature core 58 side. A sliding bearing 12 a is provided at the radial center of the inner peripheral surface of the top plate 12. The plain bearing 12a rotatably supports the other side end portion (right end portion in FIG. 1) 4d of the drive shaft 4 arranged coaxially with the rotary shaft 52.

  The plurality of planetary gears 14 are connected by a carrier plate 16 as an output unit. The carrier plate 16 is provided with a plurality of support shafts 16a at positions corresponding to the planetary gears 14, and the planetary gears 14 are rotatably supported thereon. Further, an engagement hole 16b having a serration portion 16c is provided in the center of the carrier plate 16 in the radial direction.

  On the other hand, the other end portion 4d of the drive shaft 4 is formed with a connection serration portion 4e meshed with the engagement hole 16b on the outer peripheral surface, and one end of the rotating shaft 52 (the left end in FIG. 1). ) Is inserted and fitted into the recess 4a. A slide bearing 4b is press-fitted into the inner peripheral surface of the recess 4a, and the drive shaft 4 and the rotary shaft 52 are connected so as to be relatively rotatable.

(housing)
The housing 17 has a role of fixing the starter 1 to an engine (not shown) and a role of housing the top plate 12 (planetary gear mechanism 2), the electromagnetic device 9, the clutch mechanism 5, the idle gear unit 100, and the like. Yes.
The housing 17 is mounted on one side (the left side in FIG. 1) and the other side (the right side in FIG. 1), the bracket part 171 having the openings 171a and 171c, and one of the bracket parts 171 (the left side in FIG. 1) The gear cover 172 is divided. The bracket portion 171 and the gear cover 172 are each made of aluminum and are formed by die casting. And the top plate 12 is provided so that the other opening part 171c of the bracket part 171 may be obstruct | occluded.

  The bracket portion 171 has a female screw portion 171b formed along the axial direction on the outer peripheral surface on the other opening portion 171c side. Further, a bolt hole 55a is formed at a position corresponding to the female screw portion 171b in the end plate 55 disposed on the other side of the motor yoke 53 (the right end side in FIG. 1). By inserting the bolt 95 into the bolt hole 55a and screwing the bolt 95 into the female screw portion 171b, the motor portion 3 and the bracket portion 171 are integrated.

A ring-shaped stopper 94 is provided on the inner wall of the bracket portion 171 to restrict displacement of a clutch outer 18 (described later) toward the motor portion 3 side. The stopper 94 is made of resin, rubber, or the like, and can relieve an impact when the clutch outer 18 abuts.
Further, the inner wall of the bracket portion 171 is provided with a reduced diameter portion 171 d that is formed with a reduced diameter by a step closer to the one opening 171 a than the stopper 94. The stepped surface of the reduced diameter portion 171d functions as a retaining portion for preventing the electromagnetic device 9 from slipping out from one opening 171a in the bracket portion 171.

A shaft hole 174 is formed on one opening 171a side (left side in FIG. 1) of the bracket portion 171 on the radially outer side (lower side in FIG. 1) of the opening 171a. The shaft hole 174 is for rotatably supporting the vicinity of one end 102a (the left end in FIG. 1) of the idle shaft 102 described later.
In addition, an outer flange portion 171t projecting outward is integrally formed on the one opening 171a side of the bracket portion 171. The surface of the outer flange portion 171t facing the gear cover 172 is a contact surface 171e with the gear cover 172.

  The bracket portion 171 and the gear cover 172 configured as described above are determined in approximate relative positions via the positioning pins 184. The bracket portion 171 and the gear cover 172 are fastened and fixed to each other by a bolt 177a inserted from the bracket portion 171 side.

  The gear cover 172 is formed so as to cover the entire contact surface 171e of the bracket portion 171, and a pair of mounting bracket portions 172t formed so as to protrude outward from the bracket portion 171 are integrally formed. Yes. Bolt insertion holes 172b are formed in the mounting bracket portions 172t, respectively. By inserting a bolt (not shown) into the bolt insertion hole 172b, the gear cover 172 is fixed to a housing (engine, vehicle chassis, etc.) (not shown).

The gear cover 172 is formed with an accommodation recess 173 so as to open to the side facing the bracket portion 171. The housing recess 173 houses the clutch mechanism 5 and the transmission pinion gear (transmission gear) 70 and an idle gear 101 described later.
The housing recess 173 includes a pinion gear housing recess 173a in which the transmission pinion gear 70 is housed and an idle gear housing recess 173b in which the idle gear 101 is housed. And each accommodation recessed part 173a, 173b is formed so that it may connect.

Further, in the receiving recess 173, an opening portion 173c that fits in one opening portion 171a of the bracket portion 171 when the gear cover 172 and the bracket portion 171 are overlapped with each other is provided at the periphery of the opening portion of the pinion gear receiving recess portion 173a. Projected.
The inlay portion 173c is formed in a substantially C shape in which the idle gear housing recess 173b side is opened in plan view as viewed from the axial direction so as to correspond to the shape of the peripheral edge of the opening of the pinion gear housing recess 173a.

In addition, a bottomed bearing recess 47 is formed coaxially with the drive shaft 4 at the bottom 173 d of the housing recess 173. Furthermore, a shaft through hole 179 through which an idle shaft 102 described later passes is formed in the bottom 173d of the housing recess 173 on the side of the bearing recess 47.
The bearing recess 47 has an inner diameter larger than the outer diameter of the drive shaft 4. A sliding bearing 178 for rotatably supporting one side end (left side end in FIG. 1) of the drive shaft 4 is press-fitted and fixed to the bearing recess 47. The sliding bearing 178 is impregnated with a lubricating oil made of a desired base oil, so that the drive shaft 4 can be smoothly slidably contacted.

A load receiving member 50 (see FIG. 1) is disposed between the bottom of the bearing recess 47 and the one end face 4c of the drive shaft 4.
The load receiving member 50 is a flat metal member, and for example, a ring-shaped washer formed by pressing is employed. The load receiving member 50 is made of a material having higher hardness than the drive shaft 4 and excellent wear resistance. As a material of the load receiving member 50, for example, carbon tool steel such as SK85 is suitable.

  By disposing the load receiving member 50, even when a thrust load is generated on the drive shaft 4 toward one side (left side in FIG. 1), the movement of the drive shaft 4 is restricted by the load receiving member 50 provided on the gear cover 172. However, the thrust load of the drive shaft 4 can be received. Further, since the one end surface 4c of the drive shaft 4 and the load receiving member 50 are in sliding contact with each other when the drive shaft 4 is rotated, it is possible to prevent the one end surface 4c of the drive shaft 4 and the gear cover 172 from being in direct contact. Therefore, wear of the gear cover 172 can be prevented and the starter 1 having excellent durability can be obtained.

  In addition, grease for reducing friction at the time of sliding contact with the one end surface 4c of the drive shaft 4 is applied around the load receiving member 50, and the grease impregnated in the sliding bearing 178 is lubricated. Oil containing the same type of base oil as that of oil is used. For this reason, the lubricating oil of the sliding bearing 178 can be retained for a long period of time.

  An oil seal 190 and a ball bearing 180 are provided in the shaft through hole 179 of the gear cover 172 in order from the one end surface 172r side opposite to the bracket portion 171. The oil seal 190 is for preventing dust and water from entering the gear cover 172 from the outside through the shaft through hole 179. The ball bearing 180 is for rotatably supporting an idle shaft 102 described later.

  Furthermore, an inner cylindrical portion 186 and an outer cylindrical portion 187 are provided on the one end surface 172r of the gear cover 172 so as to surround the shaft through hole 179 and project on a concentric circle. The inner cylindrical portion 186 and the outer cylindrical portion 187 also have a role to prevent dust and water from entering the gear cover 172 from the outside through the shaft through hole 179.

(Clutch mechanism)
A helical spline 19 is formed at substantially the center in the axial direction of the drive shaft 4. The clutch mechanism 5 is helically engaged with the helical spline 19.
The clutch mechanism 5 includes a substantially cylindrical clutch outer 18, a clutch inner 22 formed coaxially with the clutch outer 18, and a clutch cover 6 that integrally fixes the clutch outer 18 and the clutch inner 22. ing.

  The clutch mechanism 5 transmits the rotational force from the clutch outer 18 side to the clutch inner 22. Further, the clutch mechanism 5 is configured such that the rotational force from the clutch inner 22 side is not transmitted to the clutch outer 18. Thus, the clutch mechanism 5 has a so-called known one-way clutch function. As a result, when the engine is started, when the engine is in an overrun state in which the rotational speed of the clutch inner 22 is faster than that of the clutch outer 18, the rotational force from the ring gear 23 side of the engine is cut off.

  The clutch mechanism 5 transmits the rotational force to each other when the torque difference generated between the clutch outer 18 and the clutch inner 22 and the rotational speed difference are within predetermined values. On the other hand, when the torque difference and the rotational speed difference exceed predetermined values, the transmission of the rotational force is interrupted. That is, the clutch mechanism 5 also has a so-called torque limiter function.

A sleeve 18a having a reduced diameter is integrally formed on the other side (right side in FIG. 1) of the clutch outer 18, and a helical spline 18b that meshes with the helical spline 19 of the drive shaft 4 is formed on the inner peripheral surface thereof. Yes. Accordingly, the clutch mechanism 5 is provided so as to be slidable in the axial direction with respect to the drive shaft 4.
A step portion 18 c is formed on one of the sleeves 18 a on the inner peripheral surface of the clutch outer 18. The inner peripheral surface of the stepped portion 18c is formed with a larger diameter than the inner peripheral surface of the sleeve 18a.
A clutch cover 6 described later is fixed to the outer peripheral surface of the clutch outer 18 by, for example, caulking.

The clutch inner 22 has a diameter larger than that of the sleeve 18 a of the clutch outer 18. A space is formed between the inner peripheral surfaces of the clutch inner 22 and the stepped portion 18 c and the drive shaft 4. A return spring 21 described later is disposed in this space.
A substantially disc-shaped clutch washer 64 is externally fitted and fixed to the outer peripheral surface of the clutch inner 22 at a position corresponding to one end surface of the clutch outer 18 in the radial direction.

The clutch cover 6 is a bottomed cylindrical member having a main body cylinder portion 68 and a bottom wall 66 on one side of the main body cylinder portion 68 (left side in FIG. 1). The clutch cover 6 is formed by drawing a metal plate material such as iron.
The main body cylinder portion 68 is externally inserted into the clutch outer 18 and the clutch washer 64, and is fixed to the clutch outer 18 and the clutch washer 64 by crimping the other edge portion of the main body cylinder portion 68 to the other end surface of the clutch outer 18. Is done.
An opening penetrating one and the other is formed in the approximate center of the bottom wall 66, and a reinforcing cylinder portion 67 extending from the opening toward one side in the axial direction is formed. The reinforcing cylinder portion 67 is formed concentrically with the drive shaft 4, and the drive shaft 4 is inserted therethrough.

The drive shaft 4 is provided with a movement restricting portion 20 on one side (left side in FIG. 1) of the helical spline 19.
The movement restricting portion 20 is a substantially ring-shaped member that is externally fitted to the drive shaft 4. The movement restricting portion 20 is provided in a state where movement in one axial direction is restricted by the circlip 20a, and the inner portion of the step portion 18c is capable of interfering with the step portion 18c formed in the clutch outer 18. It has a larger diameter than the peripheral surface. As will be described later, when the clutch mechanism 5 slides to one side, the step portion 18c of the clutch outer 18 and the movement restricting portion 20 interfere with each other. Thereby, the sliding movement amount to one side of the clutch mechanism 5 is regulated.

  A return spring 21 is provided between the movement restricting portion 20 and the sleeve 18 a of the clutch outer 18 and between the inner peripheral surface of the step portion 18 c and the outer peripheral surface of the drive shaft 4. The return spring 21 is formed so as to surround the drive shaft 4 and is provided in a compressed and deformed state. As a result, the clutch outer 18 is constantly biased so as to be pushed back toward the motor unit 3 side.

In the clutch mechanism 5 configured as described above, a transmission pinion gear 70 is integrally provided at the tip of the clutch inner 22.
The transmission pinion gear 70 is formed of a cylindrical portion 70a that is slidably fitted to the drive shaft 4 and an external gear portion 70b that is integrally formed on the outer peripheral surface and meshed with an idle gear 101 described later. . And the cylinder part 70a and the clutch inner 22 are integrally molded.

  An outer flange portion 73 is integrally formed on the clutch mechanism 5 side, which is the base end side of the cylindrical portion 70a, with an axial distance from the outer gear portion 70b of the transmission pinion gear 70. Two sliding bearings 72 and 72 for slidably supporting the transmission pinion gear 70 on the drive shaft 4 are provided on both axial sides of the inner peripheral surface of the cylindrical portion 70a.

(Idle gear unit)
FIG. 2 is an enlarged cross-sectional view of the idle gear unit 100. 1 and 2, the starter 1 is in a stationary state (a state in which the idle shaft 102 is retracted) below the center axis of the idle shaft 102, and the starter 1 is in an energized state (the idle shaft 102 moves forward). The state where the drive pinion mechanism 110 and the ring gear 23 of the engine (not shown) are engaged with each other is shown.

  As shown in FIGS. 1 and 2, the idle gear unit 100 includes an idle shaft 102 arranged in parallel with the drive shaft 4, and an idle gear that is integrally formed with an intermediate portion in the axial direction of the idle shaft 102 and meshes with the transmission pinion gear 70. 101 and a drive pinion mechanism 110 provided at one end 102 a of the idle shaft 102 and capable of meshing with the ring gear 23.

The idle gear 101 is formed so as to expand from the idle shaft 102 to the outer peripheral side, and an outer gear portion 101b is formed on the outer peripheral surface thereof.
Here, the reduction ratio between the external gear portion 101 b of the idle gear 101 and the external gear portion 70 b of the transmission pinion gear 70 is set so that the rotational speed of the idle gear 101 decreases with respect to the rotational speed of the transmission pinion gear 70. Yes. Thereby, the rotational torque of the idle shaft 102 can be made larger than the rotational torque of the drive shaft 4. Thus, by adjusting the gear ratio between the transmission pinion gear 70 and the idle gear 101, a torque-oriented starter or a rotation-oriented starter can be obtained.

Further, the idle gear 101 and the transmission pinion gear 70 are constituted by helical gears (helical gears).
Further, one end portion 102 a (the left end portion 102 a in FIGS. 1 and 2) of the idle shaft 102 passes through the shaft through hole 179 of the gear cover 172 and protrudes outward from the gear cover 172. That is, the front side of one end portion 102 a of the idle shaft 102 is rotatably supported by the ball bearing 180 provided on the gear cover 172.
The idle shaft 102 is supported by a shaft hole 174 having the other end 102b formed in the bracket portion 171 so as to be rotatable and slidable in the axial direction (thrust direction) via the slide bearing 103. Yes.

  Here, the gap K1 formed between the other end portion 102b of the idle shaft 102 and the shaft hole 174 of the bracket portion 171 serves as a lubricant for enhancing the slidability of the idle shaft 102 with respect to the slide bearing 103. The grease is filled. On the other hand, a grease reservoir 99 is recessed at the other end 102 b of the idle shaft 102.

  The grease reservoir 99 prevents the grease from flowing out from the gap K1 due to the pumping action when the other end 102b of the idle shaft 102 is inserted into the slide bearing 103 of the bracket 171. That is, when the volume of the gap K1 is changed by the sliding movement of the idle shaft 102 (when the volume of the gap K1 is changed to be small), the grease in the gap K1 is received by the grease reservoir 99. Thereby, it is possible to prevent grease from being scattered outside the bracket portion 171.

  The grease reservoir 99 is tapered so that the opening area gradually increases toward the end 102b. For this reason, for example, when the volume of the gap portion K1 changes so as to increase, the grease once accumulated in the grease pool portion 99 tends to flow out into the gap portion K1. Therefore, the slidability between the sliding bearing 103 and the idle shaft 102 is sufficiently ensured by the circulation of the grease between the gap K1 and the grease reservoir 99.

Further, an annular idle washer 104 is fitted on the outer peripheral portion of the idle shaft 102 on the clutch mechanism 5 side with respect to the idle gear 101. The idle washer 104 is restricted by the retaining ring 105 attached to the idle shaft 102 from slipping the idle washer 104 toward the clutch mechanism 5 side.
Further, the outer periphery of the idle washer 104 is inserted into an annular gap between the outer gear portion 70 b and the outer flange portion 73 in the transmission pinion gear 70. As a result, the idle shaft 102 having the idle gear 101 can move in the axial direction along with the transmission pinion gear 70 via the idle washer 104. The idle washer 104 is also coated with grease or the like as a lubricant.

Further, in the idle shaft 102, a stepped portion 102d is formed on the idle gear 101 side of the portion inserted through the ball bearing 180 by increasing the outer diameter. When the stepped portion 102d hits the ball bearing 180, the amount of movement of the idle shaft 102 toward the drive pinion mechanism 110 is restricted.
Further, a spline 108 is formed on the outer peripheral surface of one end portion 102 a of the idle shaft 102. The drive pinion mechanism 110 is spline fitted to the spline 108.

(Drive pinion mechanism)
The drive pinion mechanism 110 includes a substantially cylindrical pinion inner 111 that is externally fitted to one end portion 102 a of the idle shaft 102, and a substantially cylindrical pinion outer 112 that is externally fitted to the pinion inner 111. Yes. A spline 113 is formed on the tip 111 a side of the inner peripheral surface of the pinion inner 111. This spline 113 is splined to the spline 108 of the idle shaft 102. As a result, the pinion inner 111 is connected to the idle shaft 102 so as to be slidable in the axial direction and not relatively rotatable.

The length of the spline 108 of the idle shaft 102 is set longer in the axial direction than the length of the spline 113 of the pinion inner 111. Thereby, the idle shaft 102 and the pinion inner 111 are provided such that they cannot rotate relative to each other and can slide in the axial direction.
Further, the idle shaft 102 is formed with a stepped portion 102c having a diameter larger than that of the spline 108 side on the other side (right side in FIGS. 1 and 2) of the spline 108.

  On the other hand, on the inner peripheral surface of the pinion inner 111, a diameter-enlarged portion 114 that is formed to have a larger diameter by a step is provided on the stepped portion 102c side (base end 111b side) of the idle shaft 102 than the portion where the spline 113 is formed. Is formed. Further, the pinion inner 111 is formed so that the base end 111b of the pinion inner 111 and the stepped portion 102c come into contact with each other when the pinion inner 111 slides to the other side in the axial direction (the right side in FIGS. 1 and 2). ing. That is, when the pinion inner 111 slides in the axial direction with respect to the idle shaft 102, the base end 111b of the pinion inner 111 abuts against the stepped portion 102c, thereby restricting the movement of the pinion inner 111 in the other direction.

  By forming the enlarged diameter portion 114 on the inner peripheral surface of the pinion inner 111, a storage portion 116 is formed between the pinion inner 111 and the idle shaft 102. In the storage portion 116, an opening formed on the idle gear 101 side is closed by an intermediate step 102 e provided on the idle gear 101 side (right side in FIGS. 1 and 2) with respect to the spline 108 of the idle shaft 102. ing.

The storage portion 116 stores a pinion spring 117 formed so as to surround the outer peripheral surface of the idle shaft 102. The pinion spring 117 is formed of a coil spring, for example.
The pinion spring 117 is compressed and deformed by the stepped surface of the enlarged diameter portion 114 of the pinion inner 111 and the stepped portion 102 c of the idle shaft 102 in a state of being housed in the housing portion 116. As a result, the pinion inner 111 is constantly biased toward the ring gear 23 side (left side in FIGS. 1 and 2) with respect to the idle shaft 102.

Further, as will be described later, the pinion spring 117 functions as a so-called damper mechanism that absorbs an impact by elastically deforming in the axial direction when the pinion outer 112 and the ring gear 23 come into contact with each other. As a result, wear of the pinion outer 112 and the ring gear 23 is suppressed, and durability of the starter 1 is improved.
Furthermore, a retaining ring 105 that is externally fitted and fixed to the idle shaft 102 is provided at one end 102 a of the idle shaft 102. On the other hand, a recess 115 for receiving the retaining ring 105 is formed at the tip 111 a of the pinion inner 111. For this reason, the pinion inner 111 is prevented from coming off on one side of the idle shaft 102.

The pinion inner 111 is integrally formed with an outer flange portion 123 closer to the base end 111b than the center in the axial direction. The outer flange portion 123 is for restricting the movement of the pinion outer 112 in the other direction with respect to the pinion inner 111. The outer diameter of the outer flange portion 123 is set to be approximately the same as the outer diameter of the pinion outer 112.
Further, a spline 118 is formed on the outer peripheral surface of the pinion inner 111. A pinion outer 112 is spline fitted to the spline 118.

The pinion outer 112 is disposed closer to the tip 111a side than the outer flange portion 123 of the pinion inner 111. A spline 119 that is spline-fitted to the spline 118 of the pinion inner 111 is formed on the inner peripheral surface of the pinion outer 112. As a result, the pinion outer 112 is connected to the pinion inner 111 so as to be slidable in the axial direction and not relatively rotatable.
Further, an outer gear portion 112 a that meshes with the ring gear 23 is formed on the outer peripheral surface of the pinion outer 112.

  Furthermore, a spring accommodating recess 120 is formed in the base end surface 112b (on the outer flange portion 123 side) of the pinion outer 112 at most of the radial center. A wave washer 121 is provided in the spring housing recess 120. That is, the wave washer 121 is provided between the spring housing recess 120 of the pinion outer 112 and the outer flange portion 123 of the pinion inner 111. The wave washer 121 functions as a so-called damper mechanism that absorbs an impact by elastically deforming in the axial direction when the pinion outer 112 and the ring gear 23 come into contact with each other. In other words, the wave washer 121 functions as a damper mechanism when the pinion outer 112 and the ring gear 23 are out of phase with each other and the pinion outer 112 and the outer flange portion 123 of the pinion inner 111 collide with each other (for details). Will be described later). Here, the spring force of the wave washer 121 is set to be smaller than the spring force of the pinion spring 117.

  Further, the pinion outer 112 is restricted from coming off to the tip 111 a side of the pinion inner 111 by a retaining ring 122 attached to the tip 111 a side of the pinion inner 111. The wave washer 121 is slightly compressed between the spring housing recess 120 and the outer flange portion 123 in a state where the front end surface 112 c of the pinion outer 112 is in contact with the retaining ring 122. As a result, the pinion outer 112 is constantly biased toward the ring gear 23 side (left side in FIGS. 1 and 2) with respect to the pinion inner 111.

Here, the ring gear 23 and the external gear portion 112a of the pinion outer 112 are constituted by helical gears. The torsion direction of the teeth of the ring gear 23 and the external gear portion 112a of the pinion outer 112 is such that a thrust load in the direction of jumping into the ring gear 23 is generated in the drive pinion mechanism 110 when the pinion outer 112 drives the ring gear 23. Is set to
The twist direction of the external gear portion 112 a of the pinion outer 112 is set to the same direction as the twist direction of the external gear portion 101 b of the idle gear 101. On the other hand, the twist direction of the external gear portion 70 b of the transmission pinion gear 70 is set to the same direction as the twist direction of the teeth of the ring gear 23.

By the way, at the time of cranking at the start of the engine, the rotational speed of the ring gear 23 is likely to vary. Here, when a rotational speed difference is generated between the outer gear portion 112a of the pinion outer 112 and the ring gear 23 that are helically engaged, the direction of the thrust load applied to the drive pinion mechanism 110 changes.
When the rotational speed of the ring gear 23 is lower than the rotational speed of the drive pinion mechanism 110, a thrust load is generated in the drive pinion mechanism 110 in a direction approaching the ring gear 23. On the other hand, when the rotational speed of the ring gear 23 is higher than the rotational speed of the drive pinion mechanism 110, a thrust load is generated in the drive pinion mechanism 110 in a direction away from the ring gear 23 (rightward in FIG. 1).

  However, in this case, since the rotational speed of the idle gear 101 is faster than the rotational speed of the transmission pinion gear 70, the idle gear 101 has a direction opposite to the thrust load applied from the transmission pinion gear 70 and the driving pinion mechanism 110 from the ring gear 23. Thrust load is applied. For this reason, the thrust load acting on the drive pinion mechanism 110 in the direction away from the ring gear 23 is offset.

That is, the twist direction of the teeth of the idle gear 101 is set to the same direction as the twist direction of the teeth of the drive pinion mechanism 110, while the twist direction of the teeth of the transmission pinion gear 70 is the same as the twist direction of the teeth of the ring gear 23. Set to direction. For this reason, the direction of the thrust load generated in the drive pinion mechanism 110 and the direction of the thrust load generated in the idle gear 101 are reversed, and both thrust loads are offset.
At this time, it is preferable to set the thrust load in the direction in which the drive pinion mechanism 110 is separated to be larger than the thrust load in the opposite direction acting on the idle gear 101. Furthermore, the thrust load in the direction in which the drive pinion mechanism 110 is separated is preferably smaller than the attractive force by the electromagnetic device 9.

(Electromagnetic device)
As shown in FIG. 1, a yoke 25 constituting the electromagnetic device 9 is fitted and fixed to the inner peripheral surface of the housing 17 (bracket portion 171) closer to the motor portion 3 than the clutch mechanism 5. The yoke 25 is formed in a bottomed cylindrical shape made of a magnetic material, and a large part of the center in the radial direction of the bottom portion 25a is greatly opened.

  Further, an annular plunger holder 26 made of a magnetic material is provided on the end of the yoke 25 opposite to the bottom 25a. The plunger holder 26 is integrally formed with an annular holder body 26a and a plunger holder-side cylindrical portion 26b that is bent and extended from the radially inner side of the holder body 26a toward the other side in the axial direction. As a result, the distance between the later-described gear plunger 80 and the iron core 88 is reduced, so that the suction force of the iron core 88 by the plunger holder 26 (hereinafter sometimes simply referred to as “suction force”) can be increased.

An exciting coil 24 formed in a substantially cylindrical shape is housed in a housing recess 25 b formed radially inward by the yoke 25 and the plunger holder 26. That is, the holder body 26 a of the plunger holder 26 is formed so as to cover one side surface of the excitation coil 24, and the plunger holder-side cylindrical portion 26 b is bent and extended so as to face the radially inner side of the excitation coil 24. ing.
The exciting coil 24 is electrically connected to an ignition switch (not shown) via a connector 150 provided on the outer peripheral surface of the bracket portion 171.

A plunger mechanism 37 is provided in the gap between the inner peripheral surface of the excitation coil 24 and the outer peripheral surface of the drive shaft 4 so as to be slidable in the axial direction with respect to the excitation coil 24.
The plunger mechanism 37 includes a substantially cylindrical switch plunger 27 formed of a magnetic material, and a gear plunger 80 disposed in a gap between the switch plunger 27 and the outer peripheral surface of the drive shaft 4. .

  The switch plunger 27 is formed by pressing a metal plate made of a magnetic material. The switch plunger 27 is formed in a cylindrical shape so as to close the radially inner side of the housing recess 25 b formed by the yoke 25 and the plunger holder 26. In the other opening of the switch plunger 27 (the opening on the right side in FIG. 1, the opening on the motor unit 3 side), an outer flange portion 29 protruding to the outer peripheral side is integrally formed. Further, a shaft holder 29 a is formed to extend on one side of the outer flange portion 29. The shaft holder 29a is for holding a switch shaft 30 to be described later, and is formed in a U shape so as to receive an end of the switch shaft 30.

A ring member 27r is integrally provided on the inner peripheral surface of the switch plunger 27. The ring member 27r is for initially pressing the gear plunger 80 toward the ring gear 23 side when the switch plunger 27 moves toward one side (ring gear 23 side). The gear plunger 80 is provided so as to be in contact with and separated from the ring member 27r.
Further, a switch return spring 27a made of a leaf spring material that biases the switch plunger 27 in the separating direction between one end of the switch plunger 27 (left opening in FIG. 1) and the plunger holder 26. Is provided.

  The gear plunger 80 is provided on the radially inner side of the switch plunger 27 and concentrically with the switch plunger 27. The gear plunger 80 includes a plunger inner 81 disposed on the radially inner side, a plunger outer 85 disposed on the radially outer side, and a plunger spring 91 disposed between the plunger inner 81 and the plunger outer 85. ing.

  The plunger inner 81 is formed in a substantially cylindrical shape with resin or the like. The inner diameter of the plunger inner 81 is formed to be slightly larger than the outer diameter of the drive shaft 4 so that it can be inserted into the drive shaft 4. Thereby, the plunger inner 81 is provided so as to be slidable in the axial direction with respect to the drive shaft 4.

An outer flange portion 82 protruding outward in the radial direction is integrally formed at one end 81a (the left end in FIG. 1) of the plunger inner 81. As will be described later, when the plunger inner 81 slides in one direction, one end 81a of the plunger inner 81 comes into contact with the other end of the clutch outer 18, and the clutch mechanism 5 and the transmission pinion gear 70 slide in one direction. I am letting.
Plural claw portions 83 whose outer diameter gradually increases from the other side toward one side are provided at the other end 81b (right end in FIG. 1) of the plunger inner 81 in the circumferential direction. Further, a groove portion 84 is formed along the circumferential direction on one of the claw portions 83 (left side in FIG. 1).

The plunger outer 85 is formed in a substantially cylindrical shape with resin or the like, like the plunger inner 81. The inner diameter of the plunger outer 85 is formed to be slightly larger than the outer diameter of the outer flange portion 82 of the plunger inner 81, and is inserted into the plunger inner 81.
An inner flange portion 86 projecting radially inward is integrally formed at the other end 85a of the plunger outer 85 (the right end in FIG. 1).

  The inner flange portion 86 is formed so that the inner diameter is smaller than the outer diameter of the claw portion 83 of the plunger inner 81 and larger than the outer diameter of the bottom portion of the groove portion 84 of the plunger inner 81. Then, by arranging the inner flange portion 86 of the plunger outer 85 in the groove portion 84 of the plunger inner 81, the plunger inner 81 and the plunger outer 85 are integrated, and the plunger mechanism 37 is configured.

  The wall thickness of the inner flange portion 86 of the plunger outer 85 is formed thinner than the width of the groove portion 84 of the plunger inner 81. Thereby, a clearance is formed between the inner flange portion 86 of the plunger outer 85 and the groove portion 84 of the plunger inner 81. Accordingly, the plunger inner 81 and the plunger outer 85 are relatively slidable in the axial direction by the clearance between the inner flange portion 86 of the plunger outer 85 and the groove portion 84 of the plunger inner 81.

An outer flange portion 87 protruding outward in the radial direction is integrally formed at the other end 85a (the right end in FIG. 1) of the plunger outer 85. The outer flange portion 87 functions as a contact portion that contacts the ring member 27r of the switch plunger 27.
A ring-shaped iron core 88 is provided on the outer peripheral surface of the plunger outer 85 on one of the outer flange portions 87 (left side in FIG. 1). The iron core 88 is integrally formed with the plunger outer 85 by, for example, a resin mold. As will be described later, the iron core 88 is attracted to the electromagnetic device 9 with a predetermined attraction force by a magnetic flux generated when a current is supplied to the exciting coil 24.

A storage portion 90 is formed between the outer flange portion 82 of the plunger inner 81 and the inner flange portion 86 of the plunger outer 85. A plunger spring 91 formed so as to surround the outer peripheral surface of the plunger inner 81 is accommodated in the accommodating portion 90.
The plunger spring 91 is compressed and deformed by the outer flange portion 82 of the plunger inner 81 and the inner flange portion 86 of the plunger outer 85 while being accommodated in the accommodating portion 90. The plunger inner 81 is biased toward one side (left side in FIG. 1) and the plunger outer 85 is biased toward the other side (right side in FIG. 1).

  Here, the one end 81a of the plunger inner 81 and the other end of the clutch outer 18 are not in contact with each other. Therefore, the clutch outer 18 is pressed against the stopper 94 by the spring load of the return spring 21. Thus, when the starter 1 is stationary, the clutch mechanism 5 is not pushed out by the spring load of the plunger spring 91, that is, the transmission pinion gear 70 is not pushed out carelessly.

  On the other hand, in the energized state of the starter 1, when the gear plunger 80 is displaced to the maximum (left side in FIG. 1), the one end 81a of the plunger inner 81 is always in contact with the other end of the clutch outer 18 of the clutch mechanism 5. It will be in contact. That is, the plunger spring 91 functions as a backlash absorbing mechanism that prevents the occurrence of an axial gap between the clutch mechanism 5 and the gear plunger 80 and absorbs the backlash of the clutch mechanism 5.

  A switch shaft 30 is erected on the shaft holder 29a of the switch plunger 27 along the axial direction via the holder member 30a. The switch shaft 30 passes through the top plate 12 of the motor unit 3 and a brush holder 33 described later. A movable contact plate 8 of the switch unit 7 disposed adjacent to the commutator 61 of the brushed DC motor 51 is connected to the end of the switch shaft 30 protruding from the top plate 12.

  The movable contact plate 8 is attached to the switch shaft 30 so as to be slidable along the axial direction, and is floatingly supported by the switch spring 32. The movable contact plate 8 can be moved toward and away from the fixed contact plate 34 of the switch unit 7 fixed to a brush holder 33 described later.

The fixed contact plate 34 includes a first fixed contact plate 34 a disposed on the radially inner side that is the commutator 61 side across the switch shaft 30, and a second fixed disposed on the radially outer side that is the opposite side of the commutator 61. It is divided into contact plates 34b. The movable contact plate 8 is provided so as to stride over the first fixed contact plate 34a and the second fixed contact plate 34b.
The movable contact plate 8 strokes along the drive shaft 4 and comes into contact with the first fixed contact plate 34a and the second fixed contact plate 34b, whereby the first fixed contact plate 34a and the second fixed contact plate 34b are turned on. It becomes a state and is electrically connected.

Here, the clutch outer 18 of the clutch mechanism 5 is biased toward the plunger inner 81 by the return spring 21. Therefore, when the starter 1 is stationary, the clutch mechanism 5 presses the switch plunger 27 to the other side (the right side in FIG. 1) via the gear plunger 80 and the ring member 27r. As a result, the movable contact plate 8 is pressed to the other side to be in an OFF state separated from the fixed contact plate 34.
On the other hand, when the electromagnetic device 9 slides the transmission pinion gear 70 and the movable contact plate 8 to one side (left side in FIG. 1), the movable contact plate 8 is turned on and the transmission pinion gear 70 contacts the ring gear 23.

  A brush holder 33 is provided on the other side (right side in FIG. 1) of the electromagnetic device 9 and the planetary gear mechanism 2. Here, on the outer peripheral side of the second fixed contact plate 34b, a cut-and-raised portion 34c that is integrally formed by bending in the axial direction is provided. The shaft terminal 44 a passes through the outer wall 33 a of the brush holder 33 through the insertion hole of the cut and raised portion 34 c. The shaft terminal 44 a protrudes outward in the radial direction of the starter 1. Furthermore, a terminal nut 44b to which the anode of the battery is electrically connected is provided at the tip of the protruding side of the shaft terminal 44a.

The brush holder 33 is provided with a cover 45 for protecting the fixed contact plate 34 and the periphery of the switch shaft 30. The brush holder 33 and the cover 45 are fixed while being sandwiched between the motor yoke 53 and the bracket portion 171.
In the brush holder 33, four brushes 41 are arranged around the commutator 61 so as to be able to advance and retract along the radial direction. A brush spring 42 is provided on the base end side of each brush 41. Each brush 41 is urged toward the commutator 61 by the brush spring 42, and the tip of each brush 41 comes into sliding contact with the segment 62 of the commutator 61.

The four brushes 41 are composed of two anode side brushes and two cathode side brushes, and two of these anode side brushes are first fixed contacts of the fixed contact plate 34 via a pigtail (not shown). It is connected to the plate 34a. On the other hand, the anode of a battery (not shown) is electrically connected to the second fixed contact plate 34b of the fixed contact plate 34 via a terminal nut 44b.
That is, when the movable contact plate 8 comes into contact with the fixed contact plate 34, voltage is applied to two anode-side brushes of the four brushes 41 via the terminal nut 44b, the fixed contact plate 34, and a pigtail (not shown). Is applied, and a current is supplied to the coil 59.

  Of the four brushes 41, two cathode-side brushes are connected to a ring-shaped center plate via a pigtail (not shown). Then, two cathode-side brushes of the four brushes 41 are electrically connected to the cathode of the battery via the center plate, the housing 17, and the vehicle body (not shown).

(Starter operation)
Next, the operation of the starter 1 will be described.
As shown in FIG. 1, when the starter 1 is in a stationary state before supplying current to the exciting coil 24, the clutch outer 18 biased by the return spring 21 is integrated with the transmission pinion gear 70. In a state where the inner 22 is pulled, it is fully urged toward the motor unit 3 side (the right side in FIG. 1). The clutch outer 18 of the clutch mechanism 5 stops at a position where it abuts against the stopper 94. Accordingly, in the idle gear unit 100 having the idle gear 101 meshed with the transmission pinion gear 70, the drive pinion mechanism 110 is separated from the ring gear 23 and is not meshed with each other.

  Further, the switch plunger 27 is pushed back by the switch return spring 27a, and is fully moved to the motor unit 3 side (the right side in FIG. 1). The outer flange 29 of the switch plunger 27 is stopped in contact with the top plate 12. Further, the movable contact plate 8 of the switch shaft 30 erected on the outer flange portion 29 is separated from the fixed contact plate 34 and is electrically disconnected.

When an ignition switch (not shown) of the vehicle is turned on from this state, a current is supplied to the exciting coil 24 to be excited, and a magnetic path through which the magnetic flux passes through the switch plunger 27 and the gear plunger 80 is formed. As a result, the switch plunger 27 and the gear plunger 80 slide and move toward the ring gear 23 side.
At this time, since the ring member 27r is integrally provided on the inner peripheral surface of the switch plunger 27, the ring member 27r presses the gear plunger 80. That is, by initially pressing the gear plunger 80 toward the ring gear 23 side, the switch plunger 27 and the gear plunger 80 slide together toward the ring gear 23 side.

  The clutch outer 18 is in helical spline engagement with the drive shaft 4, and the sleeve 18 a is in contact with the plunger inner 81 of the gear plunger 80. Therefore, when the switch plunger 27 and the gear plunger 80 slide to the ring gear 23 side, the clutch outer 18 is pushed out while slightly rotating relative to the drive shaft 4 by the inclination angle of the helical spline 18b. Further, the transmission pinion gear 70 and the idle gear unit 100 are also pushed toward the ring gear 23 side in conjunction with the sliding movement of the gear plunger 80 via the clutch mechanism 5.

  Further, when the switch plunger 27 moves to the ring gear 23 side, the movable contact plate 8 moves toward the fixed contact plate 34 side via the outer flange portion 29 and the switch shaft 30 and comes into contact with the fixed contact plate 34. Since the movable contact plate 8 is floatingly supported so as to be axially displaceable with respect to the switch shaft 30, the pressing force of the switch spring 32 is applied to the movable contact plate 8 and the fixed contact plate 34.

  When the movable contact plate 8 comes into contact with the fixed contact plate 34, the voltage of a battery (not shown) is applied to two anode-side brushes of the four brushes 41, and the coil 59 is connected via the segment 62 of the commutator 61. Energized. Then, a magnetic field is generated in the armature core 58, and a magnetic attractive force and a repulsive force are generated between the magnetic field and the permanent magnet 57 provided in the motor yoke 53. As a result, the armature 54 starts to rotate. When the armature 54 rotates, the rotational force of the rotating shaft 52 of the armature 54 (rotational force of the motor unit 3) is transmitted to the drive shaft 4 via the planetary gear mechanism 2, and the drive shaft 4 starts to rotate. .

  As the drive shaft 4 rotates, the clutch outer 18 that meshes with the helical spline 19 of the drive shaft 4 is rotated, and an inertial force acts on the clutch mechanism 5. Then, the clutch mechanism 5 is pushed toward the ring gear 23 side along the helical spline 19 by the inertial force. Here, since the force toward the ring gear 23 is acting on the gear plunger 28, the gear plunger 28 also moves toward the ring gear 23 as the clutch mechanism 5 moves.

  When the clutch mechanism 5 is pushed out toward the ring gear 23 side, the idle gear 101 is pushed out while rotating toward the ring gear 23 side in conjunction with the transmission pinion gear 70 integrated with the clutch mechanism 5. Then, the drive pinion mechanism 110 provided at the end 102b of the idle shaft 102 is also pushed out while rotating to the ring gear 23 side integrally with the idle gear 101.

(Operation of drive pinion mechanism)
Here, the operation of the drive pinion mechanism 110 will be described with reference to FIGS. 3 (a) to 3 (c).
FIG. 3 is an explanatory view showing the operation of the drive pinion mechanism 110, and (a) to (c) show the behavior during the operation of the drive pinion mechanism 110. FIG.
First, as shown in FIG. 3A, when the drive pinion mechanism 110 starts to rotate, if the tip end surface 112c of the pinion outer 112 and the other end surface 23a of the ring gear 23 are in contact with each other, the pinion outer 112 When the phases of the ring gear 23 and the ring gear 23 are in phase, the contact state is released and meshed with each other. Then, the driving pinion mechanism 110 (pinion outer 112) is pushed out to the ring gear 23 side by the urging force of the pinion spring 117 and the wave washer 121, and the driving pinion mechanism 110 and the ring gear 23 start to mesh.

  Here, the tip end surface 112c of the pinion outer 112 and the other end surface 23a of the ring gear 23 are in contact with each other, or the axial dimension distance between them is zero, and the pinion outer 112 and the ring gear 23 3 (b), when the idle shaft 102 (drive pinion mechanism 110) is pushed out to the ring gear 23 side (see arrow Y1 in FIG. 3 (b)), the pinion The pinion outer 112 is pushed back toward the outer flange 123 with respect to the inner 111 (see arrow Y2 in FIG. 3B).

  Then, the wave washer 121 provided between the pinion outer 112 and the outer flange portion 123 is compressed and deformed while the pinion outer 112 is slightly inclined by the backlash between the pinion outer 112 and the pinion inner 111. It is crushed. Then, the base end surface 112 b of the pinion outer 112 abuts on the outer flange portion 123. In this state, the movement of the pinion outer 112 in the other direction relative to the pinion inner 111 (right direction in FIG. 3B) is restricted.

From this state, as shown in FIG. 3C, when the idle shaft 102 (drive pinion mechanism 110) is pushed toward the ring gear 23 (see arrow Y3 in FIG. 3C), the pinion inner 111 and the pinion The outer 112 and the pinion inner 111 and the pinion outer 112 are pushed back toward the clutch mechanism 5 with respect to the idle shaft 102 (see arrow Y4 in FIG. 3C).
Then, the pinion spring 117 is compressed and deformed. Thus, the pinion outer 112 is urged toward the ring gear 23 by the compression deformation of the wave washer 121 and the pinion spring 117.

  That is, the wave washer 121 functions as a damper mechanism when the pinion outer 112 and the ring gear 23 are out of phase with each other, and the pinion outer 112 and the outer flange portion 123 of the pinion inner 111 collide with each other, and the pinion outer 112 It functions as a damper mechanism that absorbs the thrust load when the (drive pinion mechanism 110) and the ring gear 23 come into contact with each other. The pinion spring 117 functions as a damper mechanism that absorbs a thrust load when the pinion outer 112 (drive pinion mechanism 110) and the ring gear 23 come into contact with each other.

Therefore, even if the pinion outer 112 and the ring gear 23 are out of phase with each other, and the tip end surface 112c of the pinion outer 112 and the other end surface 23a of the ring gear 23 are in contact with each other, the switch plunger 27 is fixed. And the wear of the pinion outer 112 (drive pinion mechanism 110) and the ring gear 23 can be suppressed.
The reason why the wave washer 121 is compressed and deformed earlier than that of the pinion spring 117 is that the spring force of the wave washer 121 is set smaller than the spring force of the pinion spring 117.

  Further, an annular idle washer 104 is fitted on the outer peripheral portion of the idle shaft 102 on the clutch mechanism 5 side with respect to the idle gear 101. The outer peripheral portion of the idle washer 104 is inserted into an annular gap between the external gear portion 70 b and the outer flange portion 73 in the transmission pinion gear 70. Therefore, when the drive pinion mechanism 110 and the ring gear 23 are engaged (when the idle shaft 102 is slid), the idle washer 104 receives an impact load applied to the transmission pinion gear 70 and the idle gear 101. For this reason, it is possible to suppress an excessive stress from being applied to the transmission pinion gear 70 and the idle gear 101.

  Further, as described above, since the pinion outer 112 (drive pinion mechanism 110) and the ring gear 23 are helically meshed, a thrust load in the direction of the ring gear 23 (the jumping direction) is generated in the pinion outer 112. And the pinion outer 112 moves toward the ring gear 23 side by this thrust load. Further, the clutch outer 18 is also pushed out toward the ring gear 23 against the urging force of the return spring 21 along the helical spline 19 by the inertial force.

  At this time, a predetermined suction force toward the ring gear 23 is applied to the gear plunger 80. Therefore, the gear plunger 80 slides toward the ring gear 23 while pressing the clutch outer 18 so as to be interlocked with the sliding movement of the clutch outer 18. In this way, the drive pinion mechanism 110 is pushed out to the ring gear 23 side, and the pinion outer 112 and the ring gear 23 are engaged at a predetermined engagement position. When the pinion outer 112 and the ring gear 23 are engaged with each other, the rotational force of the drive shaft 4 is transmitted to the ring gear 23 and the engine is started.

  Here, since the drive pinion mechanism 110 and the ring gear 23 are helically meshed, when the rotational force of the drive shaft 4 is transmitted from the drive pinion mechanism 110 to the ring gear 23, the drive pinion mechanism 110 has one side (the left side in FIG. 1). Thrust load is generated toward). The thrust load generated in the drive pinion mechanism 110 is transmitted to a retaining ring 105 provided on one side of the drive pinion mechanism 110, and then the idle shaft 102, idle gear 101, transmission pinion gear 70, clutch inner 22, clutch outer 18 and It is transmitted to the drive shaft 4 via the movement restricting portion 20 and the circlip 20a. For this reason, a thrust load is generated on the drive shaft 4 toward one side, and the drive shaft 4 slides toward the other side.

  However, a load receiving member 50 is provided on the gear cover 172 of the housing 17. Thereby, as for the drive shaft 4, the one side end surface 4c contact | abuts to the load receiving member 50, and the slide movement to one side of the drive shaft 4 is controlled. Thus, the load receiving member 50 can effectively receive the thrust load applied to the drive shaft 4.

  On the other hand, after the meshing of the pinion outer 112 (drive pinion mechanism 110) and the ring gear 23, the rotational speed of the ring gear 23 varies during cranking when starting the engine. Thereby, a thrust load is generated in the drive pinion mechanism 110 toward one side (left side in FIG. 1) and the other side (right side in FIG. 1).

Specifically, when the rotational speed of the ring gear 23 is slower than the rotational speed of the drive pinion mechanism 110, a thrust load is generated in the drive pinion mechanism 110 in the direction approaching the ring gear 23 (left side in FIG. 1).
On the other hand, when the rotational speed of the ring gear 23 is faster than the rotational speed of the drive pinion mechanism 110, a thrust load is generated in the drive pinion mechanism 110 in a direction away from the ring gear 23 (right side in FIG. 1).
In particular, in a vehicle having an idle stop function, the engine is frequently stopped / started, and the use frequency is higher than that of a general starter. Therefore, the thrust load as described above is frequently generated.

  However, a thrust load in a direction opposite to the thrust load acting on the drive pinion mechanism 110 from the ring gear 23 acts from the helical meshing portion of the idle gear 101 and the transmission pinion gear 70. That is, the twist direction of the teeth of the idle gear 101 is set to the same direction as the twist direction of the external gear portion 112 a of the pinion outer 112, while the twist direction of the teeth of the transmission pinion gear 70 is the twist direction of the teeth of the ring gear 23. Is set in the same direction as

In such a state, the rotational speed of the idle gear 101 is faster than the rotational speed of the transmission pinion gear 70, whereas the rotational speed of the ring gear 23 is faster than the rotational speed of the drive pinion mechanism 110. For this reason, the thrust load acting on the drive pinion mechanism 110 in the direction away from the ring gear 23 can be offset.
Therefore, even if a thrust load is generated in the direction away from the ring gear 23 in the drive pinion mechanism 110, an appropriate and stable helical engagement state can be maintained without releasing the helical engagement between the drive pinion mechanism 110 and the ring gear 23. .

  Further, the thrust load generated in the drive pinion mechanism 110 is transmitted to an idle washer 104 and a retaining ring 105 provided on one side of the drive pinion mechanism 110, and then via the idle shaft 102, the clutch inner 22, and the clutch washer 64. It is transmitted to the bottom wall 66 of the clutch cover 6. However, since the reinforcing cylinder portion 67 is integrally formed on the bottom wall 66 of the clutch cover 6, deformation of the clutch cover 6 in the axial direction is suppressed.

  When the engine is completely started and the rotational speed of the drive pinion mechanism 110 exceeds the rotational speed of the drive shaft 4, the one-way clutch function of the clutch mechanism 5 acts to cause the drive pinion mechanism 110 to idle. When the energization of the exciting coil 24 is stopped as the engine starts, the drive pinion mechanism 110 is detached from the ring gear 23 by the urging force of the return spring 21 with respect to the clutch outer 18, and the movable contact plate 8 is fixed to the fixed contact plate. The brushed direct current motor 51 stops at a distance from 34.

  Thus, in the above-described embodiment, the drive pinion mechanism 110 that repeatedly engages and disengages with the ring gear 23 is provided with the substantially cylindrical pinion inner 111 that is externally fitted to the one end 102a side of the idle shaft 102; A substantially cylindrical pinion outer 112 that is externally fitted to the pinion inner 111 is divided. The pinion outer 112 is connected to the pinion inner 111 so as to be slidable in the axial direction and not relatively rotatable. The pinion inner 111 is integrally formed with an outer flange portion 123 that restricts movement of the pinion outer 112 in the other direction (right direction in FIG. 1) relative to the pinion inner 111. Further, a wave washer 121 is provided between the spring housing recess 120 of the pinion outer 112 and the outer flange portion 123 of the pinion inner 111. Further, a storage portion 116 is formed between the pinion inner 111 and the idle shaft 102, and a pinion spring 117 is stored in the storage portion 116.

  For this reason, the impact when the ring gear 23 and the external gear portion 112a of the pinion outer 112 are engaged can be absorbed by the pinion spring 117 after being absorbed by the wave washer 121. That is, the impact at the time of engagement between the ring gear 23 and the pinion outer 112 can be reduced by the two elastic members of the wave washer 121 and the pinion spring 117. Therefore, wear of the drive pinion mechanism 110 can be reliably suppressed while the drive pinion mechanism 110 has a simple structure, and durability of the starter 1 can be improved.

  Further, as a means for reducing the impact between the pinion inner 111 and the pinion outer 112, by using the wave washer 121, a space between the outer flange portion 123 of the pinion inner 111 and the base end surface 112b of the pinion outer 112 is as much as possible. Space can be saved. Furthermore, by using a pinion spring 117 made of a coil spring as an impact reducing member between the pinion inner 111 and the idle shaft 102, the space between the pinion inner 111 and the idle shaft 102 can be saved as much as possible. For this reason, the drive pinion mechanism 110 as a whole can be reduced in size.

Further, the starter 1 is a so-called biaxial starter 1 in which the drive shaft 4 and the idle shaft 102 are arranged in parallel, and the drive pinion mechanism 110 is provided on the idle shaft 102. For this reason, the drive pinion mechanism 110 can be disposed at a position shifted from the drive shaft 4, and the degree of freedom in the layout of the starter 1 can be increased.
Furthermore, since the inertia applied to the idle shaft 102 is large in the above-described biaxial starter 1, the drive pinion mechanism 110 can be suitably used.

  Further, when the rotational speed of the ring gear 23 is higher than the rotational speed of the drive pinion mechanism 110, the thrust load acting on the drive pinion mechanism 110 in the direction away from the ring gear 23 can be offset. Further, it is possible to cancel the thrust load acting on the drive pinion mechanism 110 in the direction away from the ring gear 23. For this reason, an appropriate and stable helical meshing state can be maintained without releasing the helical meshing between the drive pinion mechanism 110 and the ring gear 23.

  The present invention is not limited to the above-described embodiment, and includes various modifications made to the above-described embodiment without departing from the spirit of the present invention.

For example, in the above-described embodiment, the case where the drive shaft 4 and the rotating shaft 52 of the motor unit 3 are connected via the planetary gear mechanism 2 has been described. However, the present invention is not limited to this, and various reduction mechanisms can be employed instead of the planetary gear mechanism 2.
In the above-described embodiment, the case where the starter 1 is a so-called biaxial starter in which the drive shaft 4 and the idle shaft 102 are arranged in parallel has been described. However, the present invention is not limited to this, and a so-called uniaxial starter in which the idle shaft 102 is not provided may be used. In the case of a uniaxial starter, the drive pinion mechanism 110 is provided on the drive shaft 4.

  Further, in the above-described embodiment, the case where the outer flange portion 123 that restricts the movement of the pinion outer 112 in the other direction (right direction in FIG. 1) with respect to the pinion inner 111 is integrally formed in the pinion inner 111 will be described. did. However, the present invention is not limited to this, and any one of the pinion inner 111 and the pinion outer 112 may be provided with a restricting portion that restricts sliding movement in the other axial direction. A wave washer 121 may be provided between the restricting portion and any one of the pinion inner 111 and the pinion outer 112.

Further, various elastic members can be employed in place of the wave washer 121. For example, a rubber damper may be provided instead of the wave washer 121, or a spring washer may be provided.
Further, in the above-described embodiment, the wave washer 121 is compressed and deformed earlier than the pinion spring 117 when the spring force of the wave washer 121 is set smaller than the spring force of the pinion spring 117. However, the present invention is not limited to this, and the wave washer 121 may be compressed and deformed earlier than the pinion spring 117. The spring force of the wave washer 121 may be set larger than the spring force of the pinion spring 117.

  In the above-described embodiment, the starter 1 that drives the ring gear 23 of the engine (not shown) has been described. However, the configuration of the drive pinion mechanism 110 and the motor unit 3 can be employed as a device for transmitting power to various external devices.

1. Starter (power transmission device)
3. Motor unit (power generation unit)
4 ... Drive shaft (shaft)
23 ... Ring gear 51 ... DC motor with brush (power generator)
70 ... Transmission pinion gear (transmission gear)
101 ... Idle gear 102 ... Idle shaft 110 ... Drive pinion mechanism (pinion mechanism)
111 ... Pinion inner 112 ... Pinion outer 117 ... Pinion spring (elastic member, coil spring)
121 ... Wave washer (damper part)
123 ... Outer flange (regulator)

Claims (5)

A power generator,
A shaft that rotates around the central axis under the force of the power generation unit;
A pinion mechanism that rotates in response to rotation of the shaft;
With
The pinion mechanism is
A first pinion portion that is slidable on the shaft and is non-rotatable relative to the shaft;
A second pinion portion that is movable along the axial direction of the shaft with respect to the first pinion portion and meshable with an external gear;
An elastic member that is provided between the shaft and the first pinion portion and biases the first pinion portion with a biasing force toward the external gear;
A restricting portion that is provided in any one of the first pinion portion and the second pinion portion, and restricts movement of the second pinion portion relative to the first pinion portion in a direction opposite to the external gear;
A damper portion provided between the restriction portion and any one of the first pinion portion and the second pinion portion, and a damper portion for mitigating an impact at the time of collision between the other portion and the restriction portion;
A power transmission device comprising: The first pinion portion is a cylindrical pinion inner that is externally fitted to the shaft.
The second pinion part is a pinion outer fitted around the pinion inner,
On the side opposite to the external gear of the pinion inner, the restricting portion is provided,
The power transmission device according to claim 1, wherein the damper portion is provided between the restricting portion and an axial end portion of the pinion outer. The elastic member is a coil spring;
The power transmission device according to claim 1, wherein the damper portion is a wave washer. A transmission gear slidably provided on the shaft;
An idle shaft that extends in a direction parallel to the shaft, is rotatable around a central axis, and is slidable in the central axis direction in conjunction with the sliding movement of the transmission gear;
An idle gear provided on one axial end of the idle shaft and meshing with the transmission gear;
With
The pinion mechanism is provided on the other axial end side of the idle shaft,
The power transmission device according to any one of claims 1 to 3, wherein the idle shaft functions as the shaft. The external gear is a ring gear connected to the engine;
The starter characterized by driving the ring gear by the pinion mechanism of the power transmission device according to any one of claims 1 to 4.

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