JP2006226328A - Variable diameter pulley and continuously variable transmission using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small size, low vibration and noise, and low cost variable diameter pulley, and a continuously variable transmission. <P>SOLUTION: One of sheaves 6 of the variable diameter pulley 4 is formed as one unit with an input shaft as a rotary shaft with a single member. A raceway groove 1b for a rolling bearing 50 is directly formed on the outer circumference surface 1a of the input shaft 1. The rolling bearing 50 is fitted and retained in a retention hole 101 of a housing 100 and includes a bearing outer ring 51 as a bearing raceway wheel opposing the raceway groove 1b and a plurality balls 52 as rollable rolling bodies arranged between the raceway groove 1b and the bearing outer ring 51. The rolling bearing 50 directly bears the input shaft 1 by balls 52 and rotatably supports the same. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a variable diameter pulley and a continuously variable transmission using the same.

There is a continuously variable transmission that hangs a metal belt or chain as a winding transmission node between a pair of pulleys (see, for example, Patent Documents 1 and 2).
In the continuously variable transmission, at least one pulley is configured as a variable-diameter pulley, and the variable-diameter pulley is disposed around the rotating shaft and is relatively movable in the axial direction and a pair of sheaves. And a tapered transmission surface formed on each of the opposing surfaces of the belt and on which a belt or the like is wound, and a rolling bearing that is supported by the housing and rotatably supports the rotating shaft.
JP 7-103302 A JP-A-11-132300

In this type of continuously variable transmission, in recent years, it has been desired to increase the transmission torque and increase the output without increasing the size.
However, due to the collision of the belt or the like with the pulley, the belt or the pulley vibrates and causes noise.
The present invention has been made in view of the above problems, and an object of the present invention is to provide a variable-diameter pulley that is small, has low vibration and noise, and is inexpensive, and a continuously variable transmission using the same.

  In order to achieve the above object, the present invention includes a pair of sheaves that are disposed around a rotating shaft and are relatively movable in the axial direction, and are formed on mutually facing surfaces of the pair of sheaves, In a variable diameter pulley having a tapered transmission surface to be wound and a rolling bearing that rotatably supports the rotating shaft, the rolling bearing is opposed to a raceway groove formed directly on the peripheral surface of the rotating shaft, and A bearing race ring held by a housing, and a plurality of rollable rolling elements disposed between the raceway groove and the bearing race ring, wherein the rotating shaft is directly received by the rolling element and is rotatable. A variable-diameter pulley is provided that is supported by.

  In the present invention, since the rotating shaft is directly received by the rolling elements, the support rigidity of the rotating shaft can be improved, and as a result, vibration and noise can be reduced. Further, by omitting the inner ring or the outer ring, it is possible to reduce the size and weight and to reduce the manufacturing cost. Further, it is possible to increase the bearing capacity without increasing the outer diameter of the rolling bearing. From this point as well, it is possible to improve the support rigidity and further reduce vibration and noise.

Further, when one of the pair of sheaves is integrally formed with the rotating shaft and a single member, the one sheave and the raceway groove are integrally formed with the rotating shaft by a single member. Therefore, the number of parts can be further reduced, and the manufacturing cost can be further reduced.
In addition, when a vibration damping member interposed between the bearing race and the housing is provided, vibration transmitted from the sheave to the housing via the rotating shaft can be significantly reduced.

  Further, in a continuously variable transmission including a pair of pulleys and a winding transmission node spanned between the pair of pulleys, when at least one of the pulleys includes the variable diameter pulley described above, the vibration is small and vibration and noise are generated. A small and inexpensive continuously variable transmission can be realized.

Preferred embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a schematic sectional view of a continuously variable transmission including a variable diameter pulley according to an embodiment of the present invention.
Referring to FIG. 1, in the continuously variable transmission A, variable-diameter pulleys 3 and 4 are provided on an input shaft 1 and an output shaft 2 as rotating shafts, respectively. Between these variable diameter pulleys 3 and 4, a metal power transmission chain 5 (hereinafter also simply referred to as a chain 5, which is schematically shown) is wound as a winding transmission node. This embodiment is an example in which a continuously variable transmission is applied to a transmission of an automobile. The input shaft 1 is, for example, a crankshaft of an automobile engine, and the output shaft 2 is, for example, an axle of a front wheel.

  The input shaft 1 is rotatably supported by a pair of rolling bearings 50 held by a transmission housing 100. The output shaft 2 is rotatably supported by the housing 100 by a pair of rolling bearings 60. In the example shown in FIG. 1, the rolling bearing 50 is a ball bearing and the rolling bearing 60 is a tapered roller bearing. For each, various rolling bearings such as a ball bearing, a cylindrical roller bearing, and a tapered roller bearing are used. it can.

The variable-diameter pulley 3 on the input shaft 1 side is integrally formed with the input shaft 1 and a first sheave 6 that is restricted from moving in the axial direction, and can rotate integrally with the input shaft 1 and in the axial direction. A second sheave 7 that is movably engaged and an oil chamber 8 that generates an oil pressure for driving the second sheave 7 toward the first sheave 6 are provided.
The first and second sheaves 6 and 7 have transmission surfaces 9 and 10 that face each other, and the chain 5 is sandwiched between the transmission surfaces 9 and 10. The transmission surfaces 9 and 10 are tapered so as to incline in opposite directions, and a so-called V-shaped groove is defined between them. The chain 5 has transmission surfaces 5a and 5b that engage with the transmission surfaces 9 and 10 of the corresponding sheaves 6 and 7, respectively.

The second sheave 7 includes an annular main body 11 that forms the transmission surface 10. A seal member 12 seals between the inner periphery of the main body 11 and the outer periphery of the input shaft 1. A cylindrical portion 13 extends from the outer periphery of the main body portion 11 to the side opposite to the first sheave 6. The cylindrical portion 13 is formed integrally with the main body portion 11 of the second sheave 7 with a single member.
An annular partition member 14 is interposed between the cylindrical portion 13 and the input shaft 1. The partition member 14 includes an annular plate 15 and a boss 16 formed on the inner periphery of the annular plate 15. The outer periphery of the annular plate 15 is fluid-tightly fitted to the inner periphery 13 a of the cylindrical portion 13, and the boss 16 is fluid-tightly fitted to the outer periphery of the input shaft 1.

Further, the cylindrical portion 13 of the second sheave 7 is connected to the input shaft 1 through an annular connecting member 17 so as to be integrally rotatable. Specifically, the connecting member 17 includes an annular plate 18 that is integrally rotatable on the outer periphery of the input shaft 1 and is not movable in the axial direction, and an outer periphery of the cylindrical portion 13 that extends from the outer periphery of the annular plate 18. And an annular flange 19 that is spline-fitted to 13b.
The boss 16 of the partition member 14 is received by the annular plate 18 of the connecting member 17, whereby the partition member 14 is positioned in the axial direction of the input shaft 1.

The oil chamber 8 is an annular chamber formed between the inner periphery 13 a of the cylindrical portion 13 of the second sheave 7 and the outer periphery of the input shaft 1, and the back surface 10 a of the transmission surface 10 of the second sheave 7. It is formed by partitioning in the axial direction by the wall surface 15a of the annular plate 15 of the partition wall member 14 facing this.
When oil is supplied into the oil chamber 8 through the oil passage 20 formed in the input shaft 1, the second sheave 7 moves toward the first sheave 6, and the effective diameter of the variable diameter pulley 3 with respect to the chain 5. Has become smaller.

  On the other hand, the variable-diameter pulley 4 on the output shaft 2 side has substantially the same configuration as the variable-diameter pulley 3 on the input shaft 1 side, but has a biasing spring 36 and a washer 37 composed of a damping member, which will be described later. There are mainly differences. Specifically, the variable-diameter pulley 4 includes a first sheave 21 that is integrally formed with the output shaft 2 and is restricted from moving in the axial direction, and can rotate integrally with the output shaft 2 and be axially A second sheave 22 that is movably engaged and an oil chamber 23 that generates oil pressure for driving the second sheave 22 toward the first sheave 21 are provided.

The first and second sheaves 21 and 22 have transmission surfaces 24 and 25 that face each other, and the chain 5 is sandwiched between the transmission surfaces 24 and 25. The transmission surfaces 24 and 25 are tapered so as to incline in opposite directions, and a so-called V-shaped groove is defined between them.
The second sheave 22 includes an annular main body 26 that forms the transmission surface 25. A seal member 27 seals between the inner periphery of the main body 26 and the outer periphery of the output shaft 2. A cylindrical portion 28 extends from the outer periphery of the main body portion 26 to the side opposite to the first sheave 21. The cylindrical portion 28 is formed integrally with the main body portion 26 of the second sheave 22 by a single member.

An annular partition member 29 is interposed between the tubular portion 28 and the output shaft 2. The partition member 29 includes an annular plate 30 and a boss 31 formed on the inner periphery of the annular plate 30. The outer periphery of the annular plate 30 is fluid-tightly fitted to the inner periphery 28 a of the cylindrical portion 28, and the boss 31 is fluid-tightly fitted to the outer periphery of the output shaft 2.
Further, the cylindrical portion 28 of the second sheave 22 is coupled to the output shaft 2 via an annular coupling member 32 so as to be integrally rotatable. Specifically, the connecting member 32 includes an annular plate 33 that is integrally rotatable on the outer periphery of the output shaft 2 and is not movable in the axial direction, and an outer periphery of the cylindrical portion 28 that extends from the outer periphery of the annular plate 33. And an annular flange 34 that is splined to 28b.

The boss 31 of the partition member 29 is received by the annular plate 33 of the connecting member 32, whereby the partition member 29 is positioned in the axial direction of the output shaft 2.
The oil chamber 23 is an annular chamber formed between the inner periphery 28 a of the cylindrical portion 28 of the second sheave 22 and the outer periphery of the output shaft 2, and the back surface 25 a of the transmission surface 25 of the second sheave 22. It is formed by partitioning in the axial direction by the wall surface 30a of the annular plate 30 of the partition wall member 29 facing this.

By supplying oil into the oil chamber 23 through the oil passage 35 formed in the output shaft 2, the second sheave 22 moves to the first sheave 21 side, and the effective diameter of the variable diameter pulley 4 related to the chain 5. Has become smaller.
High pressure oil is supplied into the oil chamber 8 of the variable diameter pulley 3 on the input side and the oil in the oil chamber 23 of the variable diameter pulley 4 on the output side is discharged, so that the effective diameter of the variable diameter pulley 3 is expanded. At the same time, the effective diameter of the variable diameter pulley 4 is reduced. As a result, the rotational speed of the output shaft 2 is relatively greater than the rotational speed of the input shaft 1.

Conversely, when high-pressure oil is supplied into the oil chamber 23 of the output-side variable-diameter pulley 4 and oil in the oil chamber 8 of the input-side variable-diameter pulley 3 is discharged, the input shaft 1 rotates. The rotational speed of the output shaft 2 becomes relatively small with respect to the number.
An elastic member 36 is interposed between the back surface 25 a of the transmission surface 25 of the second sheave 22 of the variable diameter pulley 4 and the wall surface 30 a of the annular plate 30 of the partition wall member 29, and this elastic member 36 connects the second sheave 22. The first sheave 21 is biased. The elastic member 36 is a compression coil spring that surrounds the periphery of the output shaft 2, and is accommodated in the oil chamber 23 of the second sheave 22 of the variable diameter pulley 4.

  A hydraulic pump (not shown) used to supply oil to the oil chambers 8 and 23 is stopped when the engine is idling or the like and is not required to supply hydraulic pressure, and is driven only when necessary. It is preferable for energy saving. When the hydraulic pump is an electric pump, the driving and stopping of the electric pump may be switched by turning on and off the energization of the electric motor for the electric pump. Further, when the hydraulic pump is driven by the engine, driving and stopping of the hydraulic pump may be switched by intermittently connecting an electromagnetic clutch interposed in a power transmission path from the engine to the hydraulic pump.

  Referring to FIGS. 1 and 2, a raceway groove 1 b for a rolling bearing 50 is formed directly on the outer peripheral surface 1 a of the input shaft 1, and the rolling bearing 50 is fitted and held in the holding hole 101 of the housing 100. And a bearing outer ring 51 as a bearing race that faces the raceway groove 1b, and balls 52 as a plurality of rolling elements that are arranged between the raceway groove 1b and the bearing outer ring 51. As shown in FIG. 2, the bearing outer ring 51 is sandwiched between a retaining ring 53 fitted in the circumferential groove 102 of the housing 100 and the positioning step portion 103 of the housing 100 to restrict axial movement.

  1 and 3, the raceway groove 2b for the rolling bearing 60 is directly formed on the outer peripheral surface 2a of the output shaft 2, and the rolling bearing 60 is fitted into the holding hole 105 of the housing 100. A bearing outer ring 61 as a bearing race ring that is held together and faces the raceway groove 2b, and a tapered roller 62 as a plurality of rolling elements that are arranged between the raceway groove 2b and the bearing outer ring 61. Including. As shown in FIG. 3, the bearing outer ring 61 is sandwiched between the retaining ring 63 fitted in the circumferential groove 106 of the housing 100 and the positioning step portion 107 of the housing 100, and the axial movement is restricted.

According to the present embodiment, since the rolling bearings 50 and 60 directly receive the input shaft 1 and the output shaft 2 as the rotating shaft by the balls 52 and the tapered rollers 62 as the rolling elements, the support rigidity can be improved. As a result, vibration and noise can be reduced.
Further, by omitting the inner rings of the rolling bearings 50 and 60, it is possible to reduce the size and weight and to reduce the manufacturing cost. Further, it is possible to increase the bearing capacity without increasing the outer diameter of the rolling bearings 50 and 60. Also in this respect, the support rigidity can be improved.

In particular, a raceway groove 1b for the first sheave 6 and the rolling bearing 50 is integrally formed on the input shaft 1 with a single member, and similarly, the first sheave 21 and the rolling bearing 60 are formed on the output shaft 2. Since the track groove 2b is formed integrally with a single member, the number of parts can be further reduced and the manufacturing cost can be further reduced.
Further, as shown in FIG. 4, vibration transmitted from the first sheave 6 to the housing 100 is caused by interposing a damping member 54 between the bearing outer ring 52 of the rolling bearing 50 and the holding hole 101 of the housing 100. It is possible to reduce noise and thereby reduce noise. Examples of the material of the damping member 54 include cast iron, Fe—Al alloy, Mn—Cu alloy, Cr alloy, Si killed steel, and Mg—Zr alloy.

The vibration damping member 54 includes a cylindrical main body 55 interposed between the outer peripheral surface of the bearing outer ring 52 and the inner peripheral surface of the holding hole 101, and between the end surface of the bearing outer ring 52 and the positioning step portion 103 of the housing 100. An intervening annular plate 56 is included separately. The retaining ring 53 is also preferably made of the same damping material as described above.
As shown in FIG. 5, the main body 55 includes a pair of divided bodies 551 and 552 having an arcuate cross section. The total peripheral length of the pair of divided bodies 551 and 552 is shorter than the outer peripheral length of the bearing outer ring 52. As a result, the fitting between the bearing outer ring 52 and the main body 55 of the vibration damping member 54 can be made dense, the vibration damping performance can be improved, and the noise can be further reduced.

A damping member having the same structure as that of the damping member 54 may be disposed between the rolling bearing 60 and the housing 100.
The present invention is not limited to the above embodiments, and for example, an outer ring type rolling bearing 70 may be used instead of the rolling bearing 50 described above. That is, as shown in FIG. 6, a cylindrical portion 1c is provided at the end of the input shaft 1 so as to surround the fixed support shaft 110 formed integrally with the housing 100, and the inner peripheral surface 1d of the cylindrical portion 1c. The track groove 1e is directly formed.

The rolling bearing 70 is a rolling element interposed between a bearing inner ring 71 as a bearing race ring held on the outer circumferential surface of the fixed support shaft 110 of the housing 100 and a raceway groove 1e on the inner circumferential surface 1d of the cylindrical portion 1c. As a ball 72. The bearing inner ring 71 is sandwiched between the retaining ring 73 and the positioning step portion 111 of the housing 100 to restrict axial movement.
Also in the present embodiment, the support rigidity can be improved by directly receiving the input shaft 1 by the balls 72 of the rolling bearing 70, and as a result, vibration and noise can be reduced. Although not shown, in this case as well, a damping member may be interposed between the bearing inner ring 71 and the housing 100.

  In the present invention, a belt may be used as the winding transmission node instead of the power transmission chain.

1 is a schematic cross-sectional view of a continuously variable transmission including a variable diameter pulley according to an embodiment of the present invention. It is an expanded sectional view of the principal part of a variable diameter pulley. It is an expanded sectional view of the principal part of a variable diameter pulley. It is sectional drawing of the principal part of the variable diameter pulley of another embodiment of this invention. It is sectional drawing of the rolling bearing and damping member of embodiment of FIG. It is sectional drawing of the principal part of the variable diameter pulley of another embodiment of this invention.

Explanation of symbols

  A ... continuously variable transmission, 1 ... input shaft (rotary shaft), 1a ... outer peripheral surface, 2 ... output shaft (rotary shaft), 2a ... outer peripheral surface, 3, 4 ... variable diameter pulley (pulley), 5 ... power transmission Chain (wound transmission node), 6 ... first sheave (one of a pair of sheaves), 7 ... second sheave, 9, 10 ... transmission surface, 21 ... first sheave (one of a pair of sheaves), 22 ... second sheave, 24, 25 ... transmission surface, 50, 60, 70 ... rolling bearing, 51, 61 ... bearing outer ring (bearing raceway), 52 ... ball (rolling element), 54 ... damping member, 55 ... Main body, 551, 552 ... Divided body, 56 ... Ring plate, 62 ... Tapered roller (rolling element), 71 ... Bearing inner ring (bearing raceway), 72 ... Ball (rolling element), 100 ... Housing

Claims (4)

A pair of sheaves that are arranged around the rotation shaft and are relatively movable in the axial direction, a tapered transmission surface on which the winding transmission nodes are wound, respectively, In a variable diameter pulley comprising a rolling bearing that rotatably supports a shaft,
The rolling bearing includes a bearing race that is opposed to a raceway groove formed directly on the peripheral surface of the rotary shaft and is held by a housing, and a rollable bearing disposed between the raceway groove and the bearing raceway. Including a plurality of rolling elements,
A variable diameter pulley characterized in that the rotating shaft is directly received by the rolling element and is rotatably supported.   2. The variable diameter pulley according to claim 1, wherein one of the pair of sheaves is integrally formed with a rotating shaft and a single member.   The variable diameter pulley according to claim 1 or 2, further comprising a damping member interposed between the bearing race and the housing. A continuously variable transmission including a pair of pulleys and a winding transmission node spanned between the pair of pulleys, wherein at least one of the pulleys includes the variable diameter pulley according to any one of claims 1 to 3. A continuously variable transmission.

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