JP3010954B2 - Belt-type continuously variable transmission for vehicles - Google Patents

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 a vehicle.

[0002]

2. Description of the Related Art An input shaft and an output shaft rotatably provided in a housing, and a V-groove formed between a fixed rotator fixed to the input shaft and the output shaft and the fixed rotator. A vehicle belt comprising: a pair of variable pulleys having a variable effective diameter having a movable rotary member provided to be able to approach and separate from the fixed rotary member, and a transmission belt wound around the pair of variable pulleys. 2. Description of the Related Art Continuously variable transmissions are known. However, in such a type of belt-type continuously variable transmission for a vehicle, the amount of change in the effective diameter of one variable pulley and the amount of change in the effective diameter of the other variable pulley when a shift of a predetermined width is performed are different. Since they do not match, even when the speed ratio is 1, 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 match. Even if it is set to, the center of the width greatly shifts near the maximum speed ratio and the minimum speed ratio, so that the transmission belt is twisted and the durability is impaired.

On the other hand, as disclosed in Japanese Utility Model Laid-Open Publication 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 technology has been proposed in which a hydraulic actuator is provided to correct a shift in the center of the width of the transmission belt in accordance with a 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 it is supported movably in the axial direction by being slid between the outer peripheral ring of the ball bearing that rotatably supports it and the housing in which it is fitted, 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 peripheral ring of the ball bearing and the housing to enable the axial movement, time-dependent distortion occurs due to the support under a high load, and There is a disadvantage that smooth movement in the direction becomes difficult, or the support accuracy is reduced, which adversely affects the transmission belt.

The present invention has been made in view of the above circumstances, and has as its object to eliminate the need for a hydraulic actuator for driving an input shaft or an output shaft in the axial direction and a control valve thereof, and The transmission is wound around the variable pulleys on the input side and the output side without loosening the fitting 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 that can match the center of the width of the belt.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the gist of the present invention is to provide an input shaft and an output shaft rotatably provided on a housing, and to be fixed to the input shaft and the output shaft. A pair of variable pulleys, each having a variable effective diameter, having a fixed rotator and a movable rotator provided so as to be able to approach and separate from the fixed rotator with a V-groove formed between the fixed rotator and the fixed rotator. A transmission belt wound around the pair of variable pulleys, in order to support at least one of the input shaft and the output shaft so as to be rotatable and movable in the axial direction. A rolling bearing in which an inner peripheral ring and an outer peripheral ring are relatively movable in an axial direction, and the inner peripheral ring and the outer peripheral ring of the rolling bearing are connected to at least one of the input shaft and the output shaft and the housing. It lies in the fact that each of the ring was fixed.

[0007]

In this way, in order to support at least one of the input shaft and the output shaft rotatably and movably in the axial direction, a rolling bearing is provided in which the inner peripheral ring and the outer peripheral ring can relatively move in the axial direction. And the inner and outer peripheral wheels of the rolling bearing are fixed to at least one of the input shaft and the output shaft and the housing, respectively, so that at least one of the input shaft and the output shaft can rotate it. Since the axial movement can be performed without lowering the fitting accuracy between the outer peripheral wheel of the supporting rolling bearing and the housing, the shift of the width center of the transmission belt is automatically eliminated over the entire speed ratio range.

[0008]

Therefore, according to the present invention, a hydraulic actuator for driving an input shaft or an output shaft in the axial direction and a control valve thereof are not required, and the belt-type continuously variable transmission can be made small, simple and inexpensive. . Also, unlike the conventional case, there is no need to loosen the fitting accuracy 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 possible to solve the problem that the smooth movement in the axial direction becomes difficult due to the occurrence of the distortion in the axial direction, and the adverse effect on the transmission belt due to the decrease in the support accuracy is eliminated.

[0009]

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

FIG. 1 is a skeleton diagram for explaining a driving force transmission system of a lateral transaxle for an FF vehicle, which is an example of a belt type continuously variable transmission for a vehicle to which the present invention is applied. In the figure, the power of an engine 10 is 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. The power is transmitted to the wheels 26 connected to the drive shaft 24 via the dynamic gear device 22.

The fluid coupling 12 is connected to the engine 1
Pump wheel 30 connected to crankshaft 28
, A turbine impeller 32 rotated by oil from the pump impeller 30, an output shaft 34 connected to the turbine impeller 32 so as to be relatively non-rotatable, and an output shaft 34 via a damper 36. A lock-up clutch 38 is provided. The pump impeller 30 includes a hydraulic pump 40.
Are connected to generate hydraulic pressure for operating the hydraulic actuator of each section.

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

Therefore, when the forward clutch 62 is engaged in a state where the reverse brake 66 is released, the output shaft 34 and the carrier 60 are non-rotatably connected to each other, and the input shaft 58 is integrated with the output shaft 34. , The vehicle is made to travel forward. However, when the forward clutch 62 is released and the reverse brake 66 is engaged, the rotation of the ring gear 52 is prevented, 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. Gear ratio γ _G1 (= output shaft 3
(The rotation speed of 4 / the rotation speed of the input shaft 58), the input shaft 58 is reversely rotated with respect to the output shaft 34, so that the vehicle travels backward.

The CVT 16 includes an input shaft 58 and an output shaft 70 rotatably disposed about an axis parallel to the axis a of the input shaft 58. The input shaft 58 and the output shaft 70 are provided. Are provided with a drive-side variable pulley 72 and a driven-side variable pulley 74, respectively, and a transmission belt 76 is wound between the two variable pulleys 72 and 74. Variable pulleys 72 and 74 are fixed rotating bodies 78 and 8 fixed to input shaft 58 and output shaft 70, respectively.
0 and movable rotators 82 and 84 provided on the input shaft 58 and the output shaft 70 so as to be movable in the axial direction and not to rotate relatively around the axes, respectively. By being moved in the axial direction by hydraulic cylinders 86 and 88 as driving means disposed, the width of the V-groove,
Of the CVT 16 (= rotational speed of the input shaft 58 / rotational speed of the output shaft 70) is changed.

The stepped transmission 18 is a single pinion type planetary gear type automatic transmission, and is disposed concentrically with the output shaft 70 on the rear side of the fixed rotary body 80 of the driven variable pulley 74. . This planetary gear device is meshed with a sun gear 90 rotatably disposed concentrically with an output shaft 70, a ring gear 92 connected to the output shaft 70 so as to be relatively non-rotatable, and the sun gear 90 and the ring gear 92. And a carrier 98 rotatably supporting the planetary gear 94 and connected to the second output shaft 96 so as to be relatively non-rotatable. A multi-plate high-speed clutch 10 is provided between the sun gear 90 and the carrier 98.
0 is provided, and a one-way clutch 102 and a multi-plate low-speed brake 104 are provided in series between the sun gear 90 and the housing 64. The engagement of the high-speed clutch 100 and the low-speed brake 104 is controlled by a hydraulic cylinder (not shown). The one-way clutch 102 controls the sun gear when the engagement of the low-speed brake 104 is controlled. The rotation of the ring gear 92 in the direction opposite to the rotation direction of the ring gear 92 during forward movement is prevented, but the rotation in the opposite direction is allowed.

[0016] Thus, in the state where the low speed stage brake 104 is engaged controlled with high-speed-stage clutch 100 is released, the output shaft 70 is rotated in a direction to advance the vehicle, carrier 98 further second Output shaft 9
The output shaft 70 is operated by the one-way clutch 102.
Gear ratio γ _G2 (= rotation speed of output shaft 70 / rotation speed of second output shaft 96), that is, a higher gear (smaller reduction) than the gear ratio in the case of using the Ravigneaux type compound planetary gear device. Ratio). Conversely, when the low-speed gear brake 104 is released and the high-speed gear clutch 100 is controlled to be engaged, the sun gear 90 and the carrier 98 are connected to each other so 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 speed ratio γ _G2 = 1. During forward movement, the low speed brake 104
Can be switched by controlling the engagement of the high speed clutch 100 while maintaining the engagement.

A first gear 110 is provided on the second output shaft 96, and a second gear 1 is provided on the intermediate shaft 112.
14 is engaged. The intermediate shaft 112 is rotatably disposed around an axis c parallel to the axis b of the second output shaft 96, and the large-diameter gear 11 of the differential gear device 22.
And a third gear 118 meshed with the second gear 6. Second
The gear 114 has a larger diameter than the first gear 110 and the third gear 1
18 has a smaller diameter than 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 includes a pair of differential small gears 120 rotatably supported about an axis perpendicular to the rotation axis d of the drive shaft 24 and rotating integrally with the large-diameter gear 116.
And a pair of differential large gears 122 meshed with the differential small gear 120 and connected to the drive shaft 24. Therefore, the power transmitted from the reduction gear device 20 is equally 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 is provided with a pair of a first rolling bearing 130 and a second rolling bearing 13.
2 rotatably supported by the housing 64. The first rolling bearing 130 is an inner peripheral wheel 1 that is press-fitted to an end of the input shaft 58 on the fixed rotating body 78 side.
34 and a bearing fitting hole 136 formed in the housing 64.
An outer ring 138 fitted into the inner ring by press fitting, and a retainer 1 between the inner ring 134 and the outer ring 138.
And a plurality of cylindrical rolling elements 142 which are spaced from each other by 40. A pair of inward flanges 144 are provided at both ends in the width direction of the outer peripheral wheel 138, so that relative movement in the axial direction between the outer peripheral wheel 138 and the cylindrical rolling element 142 is prevented. However, one end of the inner peripheral ring 134 is in contact with the fixed rotating body 78 and the cylindrical rolling element 1
Outward flange 14 separated by a predetermined dimension A from 42
6, the inner peripheral ring 134 and the cylindrical rolling element 14
The relative movement in the axial direction between the outer flange 2 and the outer peripheral ring 138 is possible up to a 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 movable rotating body 82 side until it comes into contact with the hydraulic cylinder 86, and is tightened by a nut 148 screwed to the input shaft 58. The inner peripheral ring 150 fitted and the outer peripheral ring 154 fitted by press-fitting into a bearing fitting hole 152 formed in the housing 64.
And a plurality of cylindrical rolling elements 158 which are spaced from each other by a retainer 156 between the inner peripheral wheel 150 and the outer peripheral wheel 154. Outer ring 154
Are provided with a pair of inward flanges 160 at both ends in the width direction, so that relative movement in the axial direction between the outer peripheral wheel 154 and the cylindrical rolling element 158 is prevented. However, one end of the inner peripheral ring 150 is provided with an outward flange 162 which is in contact with the hydraulic cylinder 86 and is separated from the cylindrical rolling element 158 by a predetermined dimension B, so that the inner peripheral ring 150 and the cylindrical rolling element are provided. The relative movement in the axial direction between the outer circumferential ring 158 and the outer peripheral ring 154 causes the outward flange 162 to move in the cylindrical rolling element 15.
8 is possible.

As described above, a gap having a dimension 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 of the second rolling bearing 132 is externally provided. Since a gap of dimension B is provided between the direction flange 162 and the direction flange 162, the input shaft 58 is allowed to move in the axial direction within a range of the distance A + B with respect to the housing 64. First rolling bearing 130 and second rolling bearing 130
Since an oil film is formed between the cylindrical rolling elements 142 and 158 of the rolling bearing 132 and the inner peripheral rings 134 and 150, the axial movement of the input shaft 58 is extremely smooth, so that the power transmission is performed. When a deviation occurs between the width center of the belt 76 on the variable pulley 72 side and the width center 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 a direction in which is canceled.

The moving distance A + B of the input shaft 58 is defined by the distance between the center of the width of the portion of the transmission belt 76 wound around the driving-side variable pulley 72 and the center of the width 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 speed ratio change range. 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 speed ratio γ is 1.

The carrier 60 has a cylindrical connecting portion 1.
66 are protruded in the axial direction, and the cylindrical connecting portion 16
Device 6 for switching between forward and backward movement between the inner peripheral teeth formed on the shaft 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 on the fourth side. The surfaces of the inner peripheral teeth and the spline teeth are preferably coated with a resin using an epoxy resin or the like in order to facilitate the movement of the input shaft 58 in the axial direction.

In the CVT 16 configured as described above,
In order to rotatably support the input shaft 58, there are provided a first rolling bearing 130 and a second rolling bearing 132 in which the inner circumferential ring and the outer circumferential ring are relatively movable in the axial direction, and the first rolling bearing 130 and the second rolling bearing 132 are provided. Inner peripheral rings 134 and 150 and outer peripheral ring 13 of second rolling bearing 132
8 and 154 are fixed to the input shaft 58 and the housing 64, respectively. Therefore, the input shaft 58 is rotatably supported by the outer peripheral rings 138 and 154 of the first rolling bearing 130 and the second rolling bearing 132 and the housing. Since it is possible to move in the axial direction without lowering the fitting accuracy with the 64 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, there is no need for a hydraulic actuator for driving the input shaft 58 in the axial direction and a control valve thereof for eliminating the displacement of the center of the width of the transmission belt 76 over the entire speed ratio range. The belt-type continuously variable transmission is small, simple, and inexpensive. Also, unlike the conventional case, there is no need to loosen the fitting accuracy 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 possible to solve the problem that the smooth movement in the axial direction becomes difficult due to the occurrence of the distortion in the axial direction, and the adverse effect on the transmission belt due to the decrease in the support accuracy is eliminated.

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

Further, according to the present embodiment, since the outward flanges 146 and 162 of the first rolling bearing 130 and the second rolling bearing 132 prevent the relative movement of the input shaft 58 in the axial direction within A + B. As a result, the axial movement of the input shaft 58 becomes excessively transient due to an external force such as inertia or the speed change operation of the CVT 16, and the torsion of the transmission belt 76 due to the transient movement is prevented. There are advantages.

While the embodiment of the present invention has been described in detail with reference to the drawings, the present invention can be embodied in other forms.

For example, in the above-described embodiment, the carrier 60 and the input shaft 58 are connected in the axial direction by spline-fitting the inner peripheral teeth of the cylindrical connecting portion 166 and the outer peripheral teeth of the shaft end of the input shaft 58. Are relatively movably connected to each other through a plurality of balls accommodated in a plurality of axial grooves formed on the inner peripheral surface of the cylindrical coupling portion 166 and the outer periphery of the shaft end of the input shaft 58, respectively. A ball spline movably connected in the axial direction may be used.

In the above-described embodiment, the input shaft 5 is provided by the first rolling bearing 130 and the second rolling bearing 132.
8 is supported movably in the axial direction, the output shaft 70 may be supported movably in the axial direction, or both the input shaft 58 and the output shaft 70 may be supported movably in the axial direction. May be done.

In the CVT 16 of the above-described embodiment, the forward / reverse switching device 14 is provided on the side of the variable pulley 72 opposite to the engine 10, and the forward two-stage auxiliary transmission 18 is provided on the variable pulley 74 on the engine 10 side. 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,
A type that does not include the auxiliary transmission 18 may be used.

Further, the transmission belt 76, to a number of link-flop <br/> rate is pivotally connected and V blocks may be of the chain type provided thereto at predetermined intervals, the hoop A plurality of blocks supported in a thickness direction and stacked in the thickness direction may transmit power by being pushed in the thickness direction.

In the above-described embodiment, when the speed 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. They can be different.

Although not specifically exemplified, the present invention can be embodied in various modified and improved forms based on the knowledge of those skilled in the art.

[Brief description of the 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 sectional view of an essential part 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)

(57) [Claims] An input shaft and an output shaft rotatably provided on a housing, and a V-groove formed between a fixed rotator fixed to the input shaft and the output shaft and the fixed rotator. A vehicle belt comprising: a pair of variable pulleys having a variable effective diameter having a movable rotary member provided to be able to approach and separate from the fixed rotary member, and a transmission belt wound around the pair of variable pulleys. in formula CVT, rotatable at least one of said input shaft and the output shaft 且
In order to support movably in one axial direction, a rolling bearing is provided in which the inner peripheral ring and the outer peripheral ring can relatively move in the axial direction, and the inner peripheral ring and the outer peripheral ring of the rolling bearing are connected to the input shaft and the output shaft. A belt-type continuously variable transmission for a vehicle, wherein the transmission is fixed to at least one of the housing and the housing.