JPH10184834A - Continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve durability of a joint part between a fixed sheave and a planetary gear (carrier) and to reduce an axial directional dimension of a continuously variable transmission. SOLUTION: An engine output is transmitted from a carrier 19 to a fixed sheave 52 via a joint part 58 so as to rotationally drive the fixed sheave 52, and this rotation is transmitted to a secondary pulley via a belt 57. In this process, although the fixed sheave 52 receives a large load A from the belt 57, the joint part 58 does not receive an excessive load as it is arranged so as to overlap a large diameter bearing 59 in the axial direction, and its durability can be improved. When the joint part 58, the large diameter bearing 59, and a small diameter bearing 60 are arranged so as to overlap each other in the axial direction, an axial dimension can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a pulley comprising a fixed sheave and a movable sheave,
The present invention relates to a continuously variable transmission having a belt wound around one pulley, and is particularly suitable for use in a transmission of an automobile, and more particularly to a support structure for a fixed sheave.

[0002]

2. Description of the Related Art Recently, an automatic continuously variable transmission incorporating a belt-type continuously variable transmission has been attracting attention as a transmission of an automobile due to demands for improvement of fuel consumption rate and improvement of driving performance.

This continuously variable transmission includes a primary pulley and a secondary pulley rotatably supported by a case, and a belt wound around these pulleys. These pulleys are composed of a fixed sheave and a movable sheave, and are configured to shift the movable sheave in the axial direction.

A forward / reverse switching device is connected to the primary pulley. The forward / reverse switching device is constituted by a planetary gear including a sun gear, a pinion gear, a ring gear, and a carrier, and transmits an output from an engine to the primary pulley. It is supposed to.

FIG. 1 is a detailed sectional view showing a support structure of a fixed sheave on the primary pulley side and the like. As is apparent from FIG. 1, the fixed sheave 200 has a boss portion 200a. 200a is rotatably supported by a case 202 (more precisely, its protruding portion 202a) via a large-diameter bearing 201. Further, a spline connecting portion 203 is formed at the tip of the boss portion 200a, and the carrier 205 is connected via the connecting portion 203.

Further, the above-mentioned ring gear 207 of the planetary gear is rotatably supported by the case projecting portion 202a via a small-diameter bearing 206.

[0007]

However, since the large-diameter bearing 201 and the spline connecting portion 203 are displaced in the axial direction, there is a problem that the dimension in the axial direction becomes large.

Further, a large load is applied to the fixed sheave 200 in the direction A in the figure by being wound around the fixed sheave 200. As described above, the large-diameter bearing 201 and the spline connecting portion 20
3 is displaced in the axial direction, a moment is generated around the large-diameter bearing 201, and as a result, a load is generated in the spline connecting portion 203 in the B direction in the figure. Therefore, there is a problem that the durability and reliability of the spline connection portion 203 are reduced.

Further, since the small-diameter bearing 206 and the large-diameter bearing 201 are arranged offset from each other in the axial direction, there is a problem that the dimension in the axial direction is increased.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a continuously variable transmission that reduces the axial dimension and improves the durability of a connection between a fixed sheave and a transmission member.

[0011]

The invention according to claim 1 is
In view of the above circumstances, the fixed sheave (52, 53) rotatably supported by the case (7), which can move in the axial direction of the fixed sheave (52, 53), and which can move in the axial direction of the fixed sheave (52, 53). 52, 53) and a movable sheave (55, 56) that rotates integrally with the hydraulic sheave (55, 56), and a hydraulic actuator (70, 92) that moves the movable sheave (55, 56) in the axial direction.
And a belt (57) wound around the pair of pulleys (50, 51).
And a transmission member (19) connected to a fixed sheave (52) in one of the pair of pulleys (50, 51) and rotating integrally therewith. A fixed sheave (52) to which the member (19) is connected is rotatably supported by the case (7) via a first bearing (59), and is connected to the transmission member (19). 58) and the first bearing (59) are arranged so as to overlap in the axial direction, in the continuously variable transmission (1).

According to a second aspect of the present invention, the transmission member (1
The fixed sheave (52) to be connected in (9) has a substantially thick cylindrical boss (52a), and the first bearing (5).
9) is arranged on the outer peripheral portion of the boss portion (52a), and the boss is formed such that the connecting portion (58) with the transmission member (19) overlaps the first bearing (59) in the axial direction. The continuously variable transmission (1), which is disposed on an inner peripheral portion of the portion (52a).

According to a third aspect of the present invention, the transmission member (1
9) is a carrier that constitutes a planetary gear (20) together with a sun gear (15), a ring gear (16) and a pinion gear (17), and the ring gear (16) is
The fixed sheave (52,
The boss portion (53) is rotatably supported by a second bearing (60) via a second bearing (60), and the second bearing (60) overlaps the first bearing (59) in the axial direction. 52a), wherein the continuously variable transmission (1) is provided.

[Operation] Based on the above structure, the transmission member (1
When one pulley (50) is rotationally driven via 9),
The fixed sheave (52) and the movable sheave (55) of the pulley (50) rotate integrally, and the rotation is performed by the belt (57).
To the other pulley (51). In this state, when the axial position of the movable sheave (55, 56) is changed by the supply hydraulic pressure of the hydraulic actuator (70, 92),
The rotation transmitted from one pulley (50) to the other pulley (51) is shifted.

The reference numerals in parentheses are for comparison with the drawings, but do not limit the configuration of the present invention.

[0016]

According to the first aspect of the present invention, since the connecting portion with the transmission member and the first bearing are arranged so as to overlap in the axial direction, the axial dimension can be reduced. Further, even if a large load acts on the fixed sheave with the belt wound thereon, no extra load acts on the connecting portion with the transmission member. Therefore, the durability and reliability of the connecting portion are improved.

According to the third aspect of the present invention, since the second bearing and the first bearing are arranged to overlap in the axial direction, the axial dimension can be reduced.

[0018]

Embodiments of the present invention will be described below with reference to the drawings.

As shown in FIG. 2, the vehicle automatic continuously variable transmission 1 includes a fluid coupling (torque converter) 2, a forward / reverse switching device 3, a belt-type continuously variable transmission (CVT) 5, and a differential device. 6 is provided. These fluid couplings 2 and the like are housed in a split type case 7.

The fluid coupling 2 includes a pump impeller 10 connected to the engine output shaft 9, a turbine liner 11 connected to the input shaft 3 a of the forward / reverse switching device 3,
A lock-up clutch 12 that directly connects the input shaft 3a and the engine output shaft 9;

The forward / reverse switching device 3 includes a sun gear 15 fixed to the input shaft 3a, a ring gear 16 rotatably supported by a fixed sheave 52 described later, a pinion gear 17 meshed with the sun gear 15, and the pinion gear 17. Planetary gear 2 composed of supporting carrier (transmission member) 19
0 is provided.

A direct clutch 22 operated by a hydraulic actuator 21 is interposed between the input shaft 3a and the carrier 19. When the direct clutch 22 is engaged, the direct clutch 22 is connected to the input shaft 3a. The carrier 19 is directly connected. The other end of the carrier 19 is spline-connected to the fixed sheave 52 (details will be described later).

Further, a reverse brake 25 operated by a hydraulic actuator 23 is connected to the ring gear 16 so that the rotation of the ring gear 16 can be stopped.

Here, the structure of the hydraulic actuator 23,
The structure of the mounting portion will be described.

On the side of the reverse brake 25,
As shown in detail in FIG. 3, the projecting portion 7a of the case 7 is arranged. The projecting portion 7a is arranged so as to surround the input shaft 3a, and an annular cylinder portion 7b is formed on the projecting portion 7a so as to open toward the reverse brake 25. An annular piston 23a is slidably disposed in the cylinder portion 7b, and the cylinder portion 7b and the piston 23a constitute a hydraulic actuator 23. A thick portion 7c is formed on the bottom surface (left surface in the figure) of the cylinder portion 7b, and the protruding portion 7a is reinforced by the thick portion 7c. The pressure receiving surface of the piston 23a is recessed corresponding to the thick portion 7c.

On the other hand, as shown in FIG. 2, the CVT 5 has a primary pulley 50 and a secondary pulley 51. The primary pulley 50 and the secondary pulley 51 are fixed sheaves 52, 53 and a movable sheave 55,
56 respectively. In addition, these pulleys 5
Between 0 and 51, a metal belt 57 is wound.

Among them, the fixed sheave 52 on the primary pulley 50 side has a substantially thick cylindrical first boss portion 52a extending on the side of the forward / reverse switching device 3 and a substantially boss portion extending on the opposite side. A thick cylindrical second boss portion 52b, and the first boss portion 52a is rotatable to the protruding portion 7a via a large-diameter bearing (first bearing) 59 disposed on the outer peripheral portion thereof. It is supported by. In the present embodiment, the hydraulic actuator 23 is arranged at the same axial position as the large-diameter bearing 59 by forming the cylinder portion 7b of the hydraulic actuator 23 deeper on the fixed sheave 52 side.

As shown in detail in FIG. 3, a spline connecting portion 58 with the carrier 19 is formed on the inner peripheral portion of the first boss portion 52a so as to overlap the large-diameter bearing 59 in the axial direction. The carrier 19 is connected to the fixed sheave 52 via the spline connecting portion 58 and integrally rotates, and the rotation from the forward / reverse switching device 3 is
0 is transmitted. Further, an annular concave portion 52c is formed at the tip of the first boss portion 52a, and a small-diameter bearing (second bearing) is formed in the concave portion 52c so as to overlap the large-diameter bearing 59 in the axial direction. 60 are arranged. The ring gear 16 described above is rotatably supported by the fixed sheave 52 via the small-diameter bearing 60.

The end of the second boss 52b and the case 7
A bearing 61 is interposed between the fixed sheave 52 and the fixed sheave 52.
It is rotatably supported by two bearings 59, 61 interposed between 52b and case 7.

On the other hand, the movable sheave 55 is
Through a ball spline 64 so as to be able to move in the axial direction and rotate integrally with the fixed sheave 52.
The movable sheave 55 is supported by the boss 52b, and is configured to be moved in the axial direction by a double piston type hydraulic actuator 70.

As shown in detail in FIG. 4, the hydraulic actuator 70 includes an outer cylinder 71 and an inner cylinder 72 fitted and fixed to the second boss portion 52b of the fixed sheave 52, and an outer peripheral portion of the movable sheave 55. And a piston member 73 fixed by swaging.

That is, the outer cylinder 71 is provided with an umbrella-shaped portion 71a extending around the second boss portion 52b.
And a cylindrical portion 71b continuous with the portion 71a. The inner cylinder 72 is formed to be curved along the rear surface of the movable sheave 55.

The piston member 73 is provided between the outer cylinder 73 and a cylindrical portion 73a axially extending from the caulking fixing portion so as to slide on the cylindrical portion 71b of the outer cylinder and the edge of the inner cylinder 72. Hydraulic chamber 7
5, a piston portion 73b bent from the cylindrical portion 73a to form a fifth portion. In addition, the movable sheave 5
5 forms a piston surface, and the inner cylinder 72
Together, they form a hydraulic chamber 77.

Before the piston member 73 is fixed to the movable sheave 55 by caulking, the movable sheave 55 has a concave portion 55a and a convex portion 55b, as shown in detail in FIG.
On the outer periphery thereof, and has a contact surface 55c formed in a direction perpendicular to the direction of the rotation axis. Further, a thin portion 73c is formed at the tip of the piston member 73, and a projection surface 73d that projects in a direction orthogonal to the axial direction is formed along with the thin portion 73c.

Then, the piston member 73 (thin portion 73c)
After the front end of the movable sheave 55 is fixed to the concave portion 55a of the movable sheave 55, the protruding surface 73d on the piston member side is brought into contact with the contact surface 55 on the movable sheave side, as shown in detail in FIG.
c. Therefore, even if the pressing force due to the hydraulic pressure acts in the direction F in the drawing, the pressing force F is received by the contact surface 55c, and hardly acts on the caulking fixing portion.

As shown in detail in FIG. 4, the outer cylinder 71 has a bulge 71c bulging leftward in the figure near the second boss 52b. The bearing 61 described above is arranged on the back surface (the left side surface in the figure). The inner race 61a of the bearing 61 has a diameter such that the inner race 61a comes into contact with a rear surface of the bulging portion 71c over a predetermined area (preferably, the entire surface of the bulging portion 71c). ) Has a recess 61b. A nut 90 screwed to the second boss 52b is disposed in the concave portion 61b, and the outer cylinder 71, the inner cylinder 72, and the bearing 61
Is positioned. That is, in the present embodiment, the diameter of the inner race 61a is set to be larger than the diameter of the nut 90.

In one of the secondary pulleys 51,
As shown in FIG. 2, the fixed sheave 53 is rotatably supported by the case 7, and the movable sheave 56 is
3 is supported by the fixed sheave 53 via a ball spline 91 so as to be movable in the axial direction and rotate integrally with the fixed sheave 53. The movable sheave 56 is provided with a hydraulic actuator 9 disposed on the back thereof.
2 allows movement in the axial direction.

An output gear 93 is fixed to the boss 53a of the fixed sheave 53. Below the output gear 93, a reduction gear mechanism 95 and a differential gear 6 are provided.
And are arranged. Among them, the reduction gear mechanism 95
Large gear 95 coaxially arranged to rotate integrally
a differential gear 6 has a ring gear 63 fixed to the differential case 62 so as to rotate integrally with the differential case 62, and a pair of gears 63 supported through a shaft in the differential case 62. , And sun gears 66, 66 meshed with the differential gears 65, 65, respectively. The sun gears 66, 66 are respectively connected to left and right front axles 96, 96 of the vehicle. The differential rotation is output. The output gear 93 on the fixed sheave side is meshed with the large gear 95a of the reduction gear mechanism 95, and the small gear 95b
Are meshed with the ring gear 63 of the differential device 6.

Next, the operation of the present embodiment will be described.

The rotation of the engine output shaft 9 is transmitted to the input shaft 3a via the fluid coupling 2. In this state, the direct clutch 22 is engaged and the reverse brake 25 is engaged.
Is released, the input shaft 3a is directly connected to the fixed sheave 52, and the rotation of the input shaft 3a is transmitted to the fixed sheave 52 via the carrier 19 as it is. Thus, the primary pulley 50 is driven to rotate forward, and the rotation is transmitted to the secondary pulley 51 via the belt 57.

The rotation of the secondary pulley 51
The power is transmitted to the reduction gear mechanism 95 via the output gear 93, and is transmitted to the differential device 6 after being reduced by the gear mechanism 95.

In this state, the hydraulic actuators 70, 92
When the axial position of the movable sheaves 55 and 56 is changed by the supplied hydraulic pressure, the rotation transmitted from the primary pulley 50 to the secondary pulley 51 is changed.

On the other hand, when the direct clutch 22 is disengaged and the reverse brake 25 is engaged, the rotation of the ring gear 63 is stopped, so that rotation in the opposite direction is transmitted to the fixed sheave 52. Then, the rotation is transmitted to the reduction gear mechanism 95 via the belt 57, the secondary pulley 51, and the output gear 93, as described above, and further transmitted to the differential device 6.

Next, the effect of the present embodiment will be described.

According to the present embodiment, the large-diameter bearing 5
9, spline connecting portion 58 and small diameter bearing 60
Are arranged at substantially the same axial position, whereby the axial dimension can be reduced.

Although a large load (see A in FIG. 3) acts on the fixed sheave 52 with the belt 57 wound thereon, the large-diameter bearing 59 and the spline connecting portion 58
Are arranged at the same axial position, so that no extra load acts on the spline connecting portion 58 as in the conventional device. As a result, the durability and reliability of the spline connection portion 58 are improved.

The support structure of the fixed sheave has been disclosed in Japanese Patent Application Laid-Open No. Sho 61-105345 (see FIG. 6) and in Japanese Patent Application Laid-Open No. Hei 4-83946. (See FIG. 1).

In FIG. 6, the case 100 has a projecting portion 100a formed therein.
, A fixed sheave 102 is rotatably supported via a large-diameter bearing 103. Then, the protrusion 10
A brake piston 105 is disposed at 0a. Since the protruding portion 100a is formed as thick as the width of the large-diameter bearing 103, the brake piston 105 is displaced from the position of the large-diameter bearing 103, which causes a problem that the axial dimension becomes long. there were.

On the other hand, the one shown in FIG.
Since the protrusion 202a of the 02 is formed thin, the dimension in the axial direction can be shortened, but there is a problem that the support of the bearing 201 becomes uncertain. It should be noted that reference numeral 2 in FIG.
Reference numeral 10 denotes a brake piston.

According to the present embodiment, the hydraulic actuator 23 can be arranged at the same axial position as the large-diameter bearing 59 by forming the cylinder portion 7b deeper on the fixed sheave 52 side, and the axial dimension can be shortened. Further, by forming the thick portion 7c on the bottom surface of the cylinder portion 7b, the strength of the protruding portion 7a can be secured, and the large-diameter bearing 59 can be reliably supported.

[Brief description of the drawings]

FIG. 1 is a detailed sectional view showing a conventional structure for supporting a fixed sheave on a primary pulley side.

FIG. 2 is a diagram showing an overall configuration of a continuously variable transmission according to the present invention.

FIG. 3 is a diagram showing a detailed structure of a forward / reverse switching device and the like.

FIG. 4 is a diagram showing a detailed structure of a primary pulley and the like.

FIG. 5 is a detailed cross-sectional view showing a joint between a movable sheave and a hydraulic actuator, (a) showing a state before joining,
(b) is a diagram showing a state after joining.

FIG. 6 is a diagram for explaining a conventional problem.

[Explanation of symbols]

 1 Continuously Variable Transmission 7 Case 15 Sun Gear 16 Ring Gear 17 Pinion Gear 19 Carrier (Transmission Member) 20 Planetary Gear 50 Primary Pulley 51 Secondary Pulley 52, 53 Fixed Sheave 52a Boss 55, 56 Movable Sheave 57 Belt 58 Spline Connection 59 Large Diameter Bearing (First bearing) 60 Small diameter bearing (Second bearing) 70,92 Hydraulic actuator

Claims (3)

[Claims] 1. A fixed sheave rotatably supported by a case, a movable sheave capable of moving in the axial direction of the fixed sheave and rotating integrally with the fixed sheave, and a hydraulic pressure for moving the movable sheave in the axial direction. A continuously variable transmission including: a pair of pulleys having an actuator; a belt wound around the pair of pulleys; and a transmission member connected to a fixed sheave in one of the pair of pulleys and integrally rotating. In the above, the fixed sheave to which the transmission member is connected is rotatably supported by the case via a first bearing, and the connection portion with the transmission member and the first bearing overlap in the axial direction. A continuously variable transmission characterized by being arranged as follows. 2. A fixed sheave to which the transmission member is connected has a substantially thick cylindrical boss portion, wherein the first bearing is disposed on an outer peripheral portion of the boss portion, and 2. The continuously variable transmission according to claim 1, wherein the connecting portion is disposed on an inner peripheral portion of the boss portion so as to overlap with the first bearing in an axial direction. 3. 3. The transmission member is a carrier that forms a planetary gear together with a sun gear, a ring gear, and a pinion gear, and the ring gear is rotatably supported via a second bearing on a fixed sheave connected to the carrier, The continuously variable transmission according to claim 2, wherein the second bearing is disposed on the boss portion so as to overlap the first bearing in the axial direction.