JPH06201006A - Belt type continuously variable transmission for vehicle - Google Patents

Abstract

PURPOSE:To provide a belt type continuously variable transmission for a vehicle to allow the matching of the width center of a gear belt without the need for a hydraulic actuator to drive an input shaft and an output shaft in an axial direction and it s control valve and without lowering precision in fitting the outer peripheral ring of a roller bearing to a housing to fit it therein. CONSTITUTION:To support an input shaft 58 in a rotatable manner, the first rolling bearing 130 and the second rolling bearing 132 are provided for an innner peripheral ring and an outer peripheral ring so as to be relatively moved in an axial direction. The inner peripheral rings 134, 150 and the outer peripheral rings 138, 154 with the rolling bearing 130 and the second rolling bearing 132 are fixed to an input shaft 58 and a housing 64, respectively. In this way, the input shaft 58 can be moved in an axial direction without lowering precision in fitting the outer peripheral rings 138, 154 to bearing fitting holes 136, 152 in the housing 64, so that the width center of a gear belt 76 is automatically prevented from dislocation, regardless of a speed change ratio.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a belt type continuously variable transmission for vehicles.

[0002]

2. Description of the Related Art An input shaft and an output shaft rotatably provided in a housing, a fixed rotor fixed to the input shaft and the output shaft, and a V groove formed between the fixed rotor. A vehicle belt including a pair of variable pulleys having a variable effective diameter, the movable pulley being provided so as to be capable of approaching and separating from the fixed rotor, and a transmission belt wound around the pair of variable pulleys. A continuously variable transmission is known. However, in such a belt type continuously variable transmission for a vehicle, the change amount of the effective diameter of one variable pulley and the change amount of the effective diameter of the other variable pulley when the gear is shifted by a predetermined width are changed. Since they do not match, the width center of the transmission belt wound around one variable pulley and the width center of the transmission belt wound around the other variable pulley should match when the gear ratio is 1. Even if it is set to, since the center of the width is largely shifted in the vicinity of the maximum speed ratio and the minimum speed ratio, the transmission belt is twisted, and the durability is deteriorated.

On the other hand, as described in Japanese Utility Model Laid-Open No. 2-36647, one of an input shaft and an output shaft is provided so as to be movable in the axial direction with respect to the housing, and is moved in the axial direction. A technique has been proposed in which a hydraulic actuator is provided to correct the deviation of the width center of the transmission belt according to the change in the V groove width of the variable pulley.

[0004]

However, in such a conventional belt type continuously variable transmission, the input shaft or the output shaft is
Since the outer peripheral ring of the ball bearing that rotatably supports it and the housing into which the ball bearing is fitted are slidably supported so as to be movable in the axial direction, a hydraulic actuator that drives in the axial direction, and It requires a control valve and an oil passage to control it. In addition, since it is necessary to loosen the fitting accuracy between the outer ring of the ball bearing and the housing to enable axial movement, time-dependent distortion occurs due to support under high load, and However, there is a drawback that smooth movement in the direction becomes difficult or the supporting accuracy is deteriorated to adversely affect the transmission belt.

The present invention has been made in view of the above circumstances, and an object thereof is to eliminate the need for a hydraulic actuator for axially driving an input shaft or an output shaft or a control valve therefor, and , The transmission wound around the variable pulleys on the input side and the output side without loosening the fitting precision between the outer ring of the ball bearing that rotatably supports the input shaft or the output shaft and the housing in which it is fitted. It is an object of the present invention to provide a belt type continuously variable transmission for a vehicle, which can match the width centers of the belts.

[0006]

The gist of the present invention for achieving the above object is to provide an input shaft and an output shaft that are rotatably provided in a housing, and those that are fixed to the input shaft and the output shaft. A pair of variable pulleys having a variable effective diameter, the fixed rotating body having a V groove formed between the fixed rotating body and the movable rotating body provided so as to be able to approach and separate from the fixed rotating body; A belt-type continuously variable transmission for a vehicle, comprising: a transmission belt wound around the pair of variable pulleys; and an inner peripheral ring and an outer periphery for rotatably supporting at least one of the input shaft and the output shaft. A rolling bearing whose wheels are relatively movable in the axial direction is provided, and inner and outer rings of the rolling bearing are fixed to at least one of the input shaft and the output shaft and the housing, respectively. Lies in the fact.

[0007]

According to this structure, in order to rotatably support at least one of the input shaft and the output shaft, the inner peripheral ring and the outer peripheral ring are provided with the rolling bearings which are relatively movable in the axial direction, and the rolling bearings. Since at least one of the input shaft and the output shaft and the housing are fixed to the inner peripheral ring and the outer peripheral ring, respectively, at least one of the input shaft and the output shaft has an outer periphery of the rolling bearing that rotatably supports the input shaft and the output shaft. Since it is possible to move in the axial direction without lowering the fitting accuracy of the wheel and the housing, the deviation of the width center of the transmission belt is automatically eliminated over the entire speed ratio range.

[0008]

Therefore, according to the present invention, the hydraulic actuator for axially driving the input shaft or the output shaft and its control valve are not required, and the belt type continuously variable transmission is compact, simple and inexpensive. . Also, unlike the conventional case, it is not necessary to loosen the fitting precision between the outer ring of the ball bearing that rotatably supports the input shaft or the output shaft and the housing in which this is fitted, so it is possible to reduce the time dependence due to support under high load. Therefore, it is possible to eliminate the problem that the smooth movement in the axial direction becomes difficult due to the distortion of the property, or the supporting accuracy is deteriorated and the transmission belt is adversely affected.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a skeleton view for explaining a driving force transmission system of an FF vehicle transverse transaxle, which is an example of a vehicle belt type continuously variable transmission to which the present invention is applied. In the figure, the power of the engine 10 includes a fluid coupling 12 with a lock-up clutch, a forward / reverse switching device 14, a belt type continuously variable transmission (hereinafter, referred to as CVT) 16, a stepped transmission 18, a reduction gear device 20, and a differential gear. It is adapted to be transmitted to the wheels 26 connected to the drive shaft 24 via the dynamic gear device 22.

The fluid coupling 12 is the engine 1
Pump impeller 30 connected to zero crankshaft 28
A turbine impeller 32 that is rotated by oil from the pump impeller 30; an output shaft 34 that is connected to the turbine impeller 32 such that it cannot rotate relative to the turbine impeller 32; and a damper 36 that is provided on the output shaft 34. A lock-up clutch 38 is provided. A hydraulic pump 40 is provided in the pump impeller 30.
Are connected so that hydraulic pressure for operating the hydraulic actuators of the respective parts is generated.

The forward / reverse switching device 14 is a double pinion type planetary gear device which can be selectively switched to a forward gear stage or a reverse gear stage according to an operating position of a shift lever (not shown), and the fluid cup with the CVT 16 interposed therebetween. It is arranged on the opposite side of the ring 12. The output shaft 34 of the fluid coupling 12 passes through the shaft center of the input shaft 58 of the CVT 16 and projects to the opposite side. The planetary gear device includes a sun gear 50 provided on the output shaft 34 so as not to rotate relative to the sun gear 50. 50, a pair of planet gears 54 and 56 that mesh with one and the other of the sun gear 50 and the ring gear 52 and mesh with each other, and planet gears 54 and 5 thereof.
6 rotatably supports the input shaft 5 of the CVT 16
8 and a carrier 60 that is connected so as not to rotate relative to each other. A multi-plate type forward clutch 62 is provided between the sun gear 50 and the carrier 60, and a multi-plate type reverse brake 66 is provided between the ring gear 52 and the housing 64.

Therefore, when the forward clutch 62 is engaged while the reverse brake 66 is released, the output shaft 34 and the carrier 60 are relatively non-rotatably connected, and the input shaft 58 is integrated with the output shaft 34. The vehicle is driven forward because it is rotated. However, when the forward clutch 62 is released and the reverse brake 66 is engaged, the rotation of the ring gear 52 is blocked, so that the carrier 60 and the input shaft 58 are in the opposite direction to the output shaft 34, that is, the direction in which the vehicle is moved backward. To gear ratio γ _G1 (= output shaft 3
Since the input shaft 58 is reversely rotated with respect to the output shaft 34 at a rotational speed of 4 / the rotational speed of the input shaft 58), the vehicle is made to travel in reverse.

The CVT 16 includes an input shaft 58 and an output shaft 70 rotatably arranged around an axis parallel to the axis a of the input shaft 58. The input shaft 58 and the output shaft 70 are provided. A drive-side variable pulley 72 and a driven-side variable pulley 74 are provided in each, and a transmission belt 76 is wound between the both variable pulleys 72, 74. The variable pulleys 72 and 74 are fixed rotating bodies 78 and 8 fixed to the input shaft 58 and the output shaft 70, respectively.
0, and movable rotating bodies 82 and 84 provided on the input shaft 58 and the output shaft 70 so as to be movable in the axial direction and non-rotatable around the shafts, respectively. The V-groove width, that is, the transmission belt 76, is moved in the axial direction by the hydraulic cylinders 86 and 88 as the driving means provided.
By changing the hanging diameter (effective diameter) of CVT 16, the gear ratio γ of CVT 16 (= rotational speed of input shaft 58 / rotational speed of output shaft 70) is changed.

The stepped transmission 18 is a single-pinion type planetary gear type automatic transmission, and is arranged concentrically with the output shaft 70 on the rear side of the fixed rotating body 80 of the driven side variable pulley 74. . This planetary gear device meshes with a sun gear 90 that is rotatably arranged concentrically with the output shaft 70, a ring gear 92 that is relatively non-rotatably connected to the output shaft 70, and the sun gear 90 and the ring gear 92. The planetary gear 94 and the carrier 98 that rotatably supports the planetary gear 94 and is connected to the second output shaft 96 so as not to rotate relative to each other. Between the sun gear 90 and the carrier 98, a multi-plate high speed clutch 10 is provided.
0 is provided, and a one-way clutch 102 and a multi-plate low speed stage brake 104 are provided in series between the sun gear 90 and the housing 64. The high speed clutch 100 and the low speed brake 104 are controlled to be engaged by hydraulic cylinders (not shown), and the one-way clutch 102 is a sun gear when the low speed brake 104 is controlled to be engaged. Although 90 is prevented from rotating in the direction opposite to the rotating direction of the ring gear 92 during forward movement, rotation in the opposite direction is permitted.

Therefore, when the high speed gear clutch 100 is released and the low speed gear brake 104 is engaged and controlled by the hydraulic cylinder 88, the output shaft 7 is released.
When 0 is rotated in the direction of advancing the vehicle, the carrier 98 and further the second output shaft 96 are moved in the same direction as the rotation direction of the output shaft 70 by the action of the one-way clutch 102, and the gear ratio γ _G2 (= output shaft). (Rotational speed of 70 / rotational speed of second output shaft 96), that is, deceleration rotation is performed at a high gear (small reduction ratio) higher than the gear ratio when the Ravigneaux compound planetary gear device is used. On the contrary, when the low-speed gear brake 104 is released and the high-speed gear clutch 100 is engagement-controlled, the sun gear 90 and the carrier 98 are coupled to each other such that they cannot rotate relative to each other. The second output shaft 96 is rotated in the same direction as the output shaft 70 at the gear ratio γ _G2 = 1. It should be noted that when the vehicle is moving forward, the shift stage can be switched by engaging the high speed clutch 100 while engaging the low speed brake 104.

A first gear 110 is provided on the second output shaft 96, and a second gear 1 provided on the intermediate shaft 112.
14 is meshed with. The intermediate shaft 112 is rotatably arranged around an axis c parallel to the axis b of the second output shaft 96, and also has a large-diameter gear 11 of the differential gear device 22.
The third gear 118 meshed with the gear No. 6 is provided. Second
The gear 114 has a diameter larger than that of the first gear 110, and the third gear 1
18 has a diameter smaller than that of the large-diameter gear 116.
The reduction gear device 20 is constituted by the gear 110, the second gear 114, and the third gear 118.

The differential gear device 22 is rotatably supported around an axis orthogonal to the rotation axis d of the drive shaft 24 and rotates in unison with the large diameter gear 116.
And a pair of large differential gears 122 that mesh with the small differential gear 120 and are connected to the drive shaft 24. Therefore, the power transmitted from the reduction gear device 20 is evenly distributed to the left and right drive shafts 24 in the differential gear device 22 and then transmitted to the left and right wheels 26.

FIG. 2 shows an actual support structure of the input shaft 58 of the CVT 16 which is a main part of FIG. In the figure,
The input shaft 58 provided with the drive side variable pulley 72 includes a pair of first rolling bearing 130 and second rolling bearing 13
It is rotatably supported by the housing 64 via 2. The first rolling bearing 130 is fitted onto the end of the input shaft 58 on the fixed rotating body 78 side by press fitting, and the inner peripheral ring 1 is attached.
34, and a bearing fitting hole 136 formed in the housing 64
The outer peripheral ring 138 fitted by press fitting into the inside, and the retainer 1 between the inner peripheral ring 134 and the outer peripheral ring 138.
It is composed of a plurality of columnar rolling elements 142 whose mutual spacing is maintained by 40. A pair of inward flanges 144 are provided at both ends in the width direction of the outer peripheral ring 138 to prevent relative movement in the axial direction between the outer peripheral ring 138 and the cylindrical rolling element 142. However, one end of the inner peripheral ring 134 is in contact with the fixed rotating body 78 and has a cylindrical rolling element 1.
Outward flange 14 separated from 42 by a predetermined dimension A
6 are provided, and the inner peripheral ring 134 and the cylindrical rolling element 14 are provided.
The relative movement in the axial direction between the two or the outer peripheral ring 138 is possible up to the position where the outward flange 146 comes into contact with the cylindrical rolling element 142.

The second rolling bearing 132 is press-fitted into the end of the input shaft 58 on the side of the movable rotor 82 until it comes into contact with the hydraulic cylinder 86, and is tightened by the nut 148 screwed to the input shaft 58. The inner ring 150 fitted and the outer ring 154 fitted into the bearing fitting hole 152 formed in the housing 64 by press fitting.
And a plurality of cylindrical rolling elements 158 whose mutual spacing is maintained by a retainer 156 between the inner peripheral ring 150 and the outer peripheral ring 154. Outer ring 154
A pair of inward flanges 160 are provided at both ends in the width direction to prevent relative movement in the axial direction between the outer peripheral ring 154 and the cylindrical rolling element 158. However, one end of the inner peripheral ring 150 is provided with an outward flange 162 that is in contact with the hydraulic cylinder 86 and is separated from the cylindrical rolling element 158 by a predetermined dimension B, and the inner peripheral ring 150 and the cylindrical rolling element are separated from each other. 158 or the relative movement in the axial direction between the outer peripheral ring 154 and the outer ring 154 causes the outward flange 162 to have a cylindrical rolling element 15.
It is possible to reach the position where it abuts on 8.

As described above, a gap of size A is provided between the cylindrical rolling element 142 of the first rolling bearing 130 and the outward flange 146, and the cylindrical rolling element 158 and the outer side of the cylindrical rolling element 158 of the second rolling bearing 132 are provided. Since a gap of size B is provided between the input flange 58 and the orientation flange 162, the input shaft 58 is allowed to move in the axial direction within the range of the distance A + B with respect to the housing 64. First rolling bearing 130 and second
Since an oil film is formed between the cylindrical rolling elements 142, 158 of the rolling bearing 132 and the inner peripheral rings 134, 150, the input shaft 58 can be moved very smoothly in the axial direction. When a deviation occurs between the width center of the belt 76 on the variable pulley 72 side and the width center of the belt 76 on the variable pulley 74 side, the deviation is caused by a component force generated based on a predetermined tension applied to the transmission belt 76. The input shaft 58 is moved in the direction in which is eliminated.

The moving distance A + B of the input shaft 58 is between the width center of the portion of the transmission belt 76 wound around the drive side variable pulley 72 and the width center of the portion wound around the driven side variable pulley 74. It is set to a value obtained by adding a predetermined margin value α to the moving distance δ required to eliminate the axial deviation over the entire change range of the transmission ratio. Further, the dimension A of the first rolling bearing 130 and the dimension B of the second rolling bearing 132 are set to be substantially equal when the gear ratio γ is 1.

The carrier 60 has a cylindrical connecting portion 1
66 is projected in the axial direction, and its cylindrical connecting portion 16
Forward / reverse switching device 1 for the inner peripheral teeth formed on 6 and the input shaft 58
The input shaft 58 is connected to the carrier 60 so as to be movable in the axial direction by meshing with the spline teeth formed at the end portion on the fourth side. The surface of the inner peripheral teeth and the spline teeth is preferably coated with a resin such as epoxy resin in order to facilitate the movement of the input shaft 58 in the axial direction.

In the CVT 16 constructed as above,
In order to rotatably support the input shaft 58, a first rolling bearing 130 and a second rolling bearing 132, in which the inner and outer rings are relatively movable in the axial direction, are provided, and the first rolling bearing 130 and Inner peripheral rings 134, 150 and outer peripheral ring 13 of the second rolling bearing 132
Since the input shafts 58 and 154 are fixed to the input shaft 58 and the housing 64, respectively, the input shaft 58 and the outer peripheral rings 138 and 154 of the first rolling bearing 130 and the second rolling bearing 132, which rotatably support the input shaft 58 and the housing 64, respectively. Since it is possible to move in the axial direction without deteriorating the fitting precision of 64 with the bearing fitting holes 136 and 152, the shift of the width center of the transmission belt 76 is automatically eliminated over the entire speed ratio range. .

Therefore, according to the present embodiment, the hydraulic actuator for axially driving the input shaft 58 and its control valve for eliminating the deviation of the width center of the transmission belt 76 over the entire speed ratio range are unnecessary, The belt type continuously variable transmission is small, simple and inexpensive. Also, unlike the conventional case, it is not necessary to loosen the fitting precision between the outer ring of the ball bearing that rotatably supports the input shaft or the output shaft and the housing in which this is fitted, so it is possible to reduce the time dependence due to support under high load. Therefore, it is possible to eliminate the problem that the smooth movement in the axial direction becomes difficult due to the distortion of the property, or the supporting accuracy is deteriorated and the transmission belt is adversely affected.

Further, conventionally, the lubricating oil is supplied to the sliding portion between the outer peripheral ring of the rolling bearing and the bearing fitting hole into which the outer peripheral ring of the rolling bearing is fitted, which is a portion that allows the input shaft 58 to move in the axial direction. Although necessary, this embodiment has an advantage that it is not necessary to provide an oil passage for supplying the lubricating oil.

Further, according to this embodiment, the relative movement in the axial direction of the input shaft 58 is within A + B by being blocked by the outward flanges 146 and 162 of the first rolling bearing 130 and the second rolling bearing 132. Therefore, it is possible to prevent the axial movement of the input shaft 58 from becoming excessive excessively due to an external force such as inertia or the gear shifting operation of the CVT 16 and the resulting twisting of the transmission belt 76. There is an advantage.

Although one embodiment of the present invention has been described in detail with reference to the drawings, the present invention can be implemented in other modes.

For example, in the above-mentioned embodiment, the carrier 60 and the input shaft 58 are axially formed by spline-fitting the inner peripheral teeth of the cylindrical connecting portion 166 and the outer peripheral teeth of the shaft end portion of the input shaft 58. Are movably connected to each other, but via a large number of balls housed in a plurality of axial grooves formed respectively on the inner peripheral surface of the cylindrical connecting portion 166 and the outer periphery of the shaft end portion of the input shaft 58. A ball spline that movably connects in the axial direction may be used.

Further, in the above-mentioned embodiment, the input shaft 5 is constituted by the first rolling bearing 130 and the second rolling bearing 132.
Although only 8 is movably supported in the axial direction, the output shaft 70 may be movably supported in the axial direction, or both the input shaft 58 and the output shaft 70 are movably supported in the axial direction. May be done.

Further, the CVT 16 of the above-described embodiment is provided with the forward / reverse switching device 14 on the side opposite to the engine 10 of the variable pulley 72, and the auxiliary transmission 18 having two forward stages on the engine 10 side of the variable pulley 74. However, the forward / reverse switching device 1
4 is the variable pulley 72 on the engine 10 side or the variable pulley 7
4 may be provided on the engine 10 side. Also,
The auxiliary transmission 18 may be of a type not provided.

The transmission belt 76 may be of a chain type in which a large number of limp plates are rotatably connected and V blocks are provided at predetermined intervals, or may be supported by a hoop and in the thickness direction. It may be of a type in which power is transmitted by pushing a large number of blocks stacked on each other in the thickness direction.

Further, in the above-mentioned embodiment, when the gear ratio γ of the CVT 16 is 1, the dimension A of the first rolling bearing 130 and the dimension B of the second rolling bearing are set to be equal. It doesn't matter if they are different.

Although not illustrated one by one, the present invention can be implemented in various modified and improved modes based on the knowledge of those skilled in the art.

[Brief description of drawings]

FIG. 1 is a skeleton diagram illustrating a driving force transmission system of a transaxle to which the present invention is applied.

FIG. 2 is a cross-sectional view of main parts for explaining in detail a support structure of an input shaft of the belt type continuously variable transmission in FIG.

[Explanation of symbols]

 16: Belt type continuously variable transmission 58: Input shaft 64: Housing 70: Output shaft 72, 74: Variable pulley 76: Transmission belt 78, 80: Fixed rotating body 82, 84: Movable rotating body 130, 132: Rolling bearing 134 , 150: Inner ring 138, 154: Outer ring

Claims (1)

[Claims] 1. A V-groove is formed between an input shaft and an output shaft rotatably provided in a housing, a fixed rotor fixed to the input shaft and the output shaft, and the fixed rotor. A vehicle belt including a pair of variable pulleys having a variable effective diameter, the movable pulley being provided so as to be capable of approaching and separating from the fixed rotor, and a transmission belt wound around the pair of variable pulleys. In a continuously variable transmission, in order to rotatably support at least one of the input shaft and the output shaft, an inner peripheral ring and an outer peripheral ring are provided with a rolling bearing that is relatively movable in the axial direction, and A belt type continuously variable transmission for a vehicle, wherein a peripheral wheel and an outer peripheral wheel are fixedly provided on at least one of the input shaft and the output shaft and the housing, respectively.