JP2021085518A - Gearbox - Google Patents

Abstract

To provide a gearbox having a structure in which a cylindrical member such as a sleeve is set between a rotation shaft and a shaft insertion part, in which improved assemblability and weight saving can be achieved.SOLUTION: A cylindrical sleeve 155 is interposed between a first secondary shaft 141 and a shaft insertion part 154 that allows the first secondary shaft 141 to be rotatably inserted into. The shaft insertion part 154 and the sleeve 155 each comprise aluminum materials. The surface of the sleeve 155 including its inner peripheral surface 158 has undergone alumetizing treatment (anodic oxidation treatment), an example of hardening treatment.SELECTED DRAWING: Figure 3

Description

The present invention relates to a transmission mounted on a vehicle.

For example, in a vehicle equipped with a transmission, the power of the engine is input to the transmission via a torque converter, and the power shifted by the transmission is transmitted to the drive wheels via a differential gear or the like. .. As the transmission, a continuously variable transmission (CVT) and a stepped automatic transmission (AT: Automatic Transmission) are widely known.

In a transmission, since it is necessary to supply oil (hydraulic oil, lubricating oil) to each part, a rotating shaft having an in-shaft oil passage extending in the axial direction is often used. Oil is supplied to the in-shaft oil passage, for example, through a supply oil passage formed in a case forming the outer shell of the transmission. Specifically, in the case, a shaft insertion portion having a cylindrical inner peripheral surface is integrally formed with the case, and a rotating shaft is rotatably inserted into the shaft insertion portion. The supply oil passage is open on the inner peripheral surface of the shaft insertion portion. On the other hand, on the rotating shaft, a communication oil passage that communicates the in-shaft oil passage and the outside of the rotating shaft is formed at a position facing the supply oil passage opened on the inner peripheral surface of the shaft insertion portion in the shaft radial direction. ing. The space connecting the supply oil passage and the communicating oil passage between the rotating shaft and the shaft insertion portion is closed by seal rings provided on both sides of the space in the axial direction.

Japanese Unexamined Patent Publication No. 2012-192855

In consideration of wear resistance to sliding of the seal ring, an iron sleeve may be set between the rotating shaft and the shaft insertion portion. In a configuration in which hydraulic oil is supplied from the oil passage in the shaft to the clutch, etc., when setting the sleeve, oil leakage from between the shaft insertion part and the sleeve is controlled in order to accurately control the supply of hydraulic oil. Need arises.

However, considering that a difference in thermal expansion occurs between the case (shaft insertion part) and the sleeve, a configuration is adopted in which the sleeve is press-fitted into the shaft insertion part, and there is a gap between the shaft insertion part and the sleeve even at high temperatures. The press-fitting allowance must be set large so that it does not occur, and the shaft insertion portion, the sleeve, and the assembling property deteriorate. Further, in the configuration in which the sleeve is press-fitted into the shaft insertion portion, rigidity (thickness) is required for the shaft insertion portion, and the mass of the transmission (case) increases.

An object of the present invention is to provide a transmission capable of improving assembling property and reducing weight in a configuration in which a cylindrical member such as a sleeve is set between a rotating shaft and a shaft insertion portion. ..

In order to achieve the above object, the transmission according to the present invention has a rotating shaft, a cylindrical inner peripheral surface, a shaft insertion portion through which the rotating shaft is rotatably inserted, and a rotating shaft and a shaft insertion portion. A shaft including a cylindrical cylindrical member interposed between the two, and a seal ring fixed to the outer peripheral surface of the rotating shaft and rubbed against the inner peripheral surface of the cylindrical member as the rotating shaft rotates. The insertion portion and the cylindrical member are made of an aluminum-based material, and at least the inner peripheral surface of the cylindrical member is hard-treated.

According to this configuration, a cylindrical member is interposed between the rotating shaft and the shaft insertion portion through which the rotating shaft is rotatably inserted. Since both the shaft insertion portion and the cylindrical member are made of an aluminum-based material, it is possible to suppress the occurrence of a difference in thermal expansion between them. Therefore, the inner peripheral surface of the shaft insertion portion and the outer peripheral surface of the cylindrical member can be formed to have substantially the same diameter, and the cylindrical member can be inserted without being press-fitted into the shaft insertion portion. As a result, the workability when assembling the cylindrical member to the shaft insertion portion, that is, the assembling property between the shaft insertion portion and the cylindrical member is improved. Further, the rigidity (thickness) of the shaft insertion portion can be reduced as compared with the configuration in which the cylindrical member is press-fitted into the shaft insertion portion. As a result, the mass of the shaft insertion portion can be reduced, and the mass of the transmission can be reduced.

Further, since the cylindrical member has a cylindrical shape, centerless processing can be adopted for manufacturing the cylindrical member, and by adopting the centerless processing, the dimensional accuracy of the cylindrical member can be improved. If the dimensional accuracy of the cylindrical member is high, it is possible to eliminate the gap between the inner peripheral surface of the shaft insertion portion and the outer peripheral surface of the cylindrical member, and it is possible to reduce oil leakage from between them.

In order to provide the cylindrical member so that it cannot rotate relative to the shaft insertion portion, the transmission may further include a lock plate that is connected to the cylindrical member so that it cannot rotate relative to the shaft insertion portion and is fixed to the shaft insertion portion. Good.

Further, an oil passage opened on the inner peripheral surface of the shaft insertion portion is formed, and the cylindrical member is provided with a lock plate so that the cylindrical member cannot rotate relative to the shaft insertion portion. An oil hole communicating with the oil passage may be formed at a position facing the open end of the oil passage in the axial direction of the rotating shaft.

In this case, the lock plate is preferably made of an aluminum-based material. As a result, it is possible to suppress the occurrence of a difference in thermal expansion between the lock plate and the shaft insertion portion and the cylindrical member, and it is possible to suppress the relative position of the oil passage and the oil hole from shifting.

According to the present invention, the assembling property between the shaft insertion portion and the cylindrical member can be improved. Further, the weight of the shaft insertion portion can be reduced, and the weight of the transmission can be reduced.

It is sectional drawing which shows the structure of the speed change unit which concerns on one Embodiment of this invention. It is a skeleton diagram which graphically shows the structure of a CVT. It is sectional drawing which enlarges and shows the vicinity of the connection part of the 1st secondary shaft and 2nd secondary shaft. It is a perspective view of a sleeve and a lock plate, and shows the state which the sleeve and the lock plate are seen from diagonally rearward.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<Transmission unit>
FIG. 1 is a cross-sectional view showing the configuration of a speed change unit 1 according to an embodiment of the present invention. In the cross-sectional views after FIG. 1, the addition of hatching representing the cross section is omitted.

The speed change unit 1 is a unit mounted on a vehicle to shift the power generated by the engine 2 (E / G) 2 as a driving source for traveling. The vehicle uses an FR (front engine / rear drive) layout.

The engine 2 is, for example, a 3-cylinder 4-stroke engine, and is mounted vertically with the crankshaft oriented vertically with respect to the front-rear direction of the vehicle body. The number of cylinders of the engine 2 is not limited to 3 cylinders, and may be 4 cylinders or more, or 2 cylinders or less. Further, the number of strokes of the engine 2 is not limited to 4 strokes, and may be 2 strokes.

The transmission unit 1 includes a torque converter 4 and a CVT (Continuously Variable Transmission) 5 in a unit case 3 forming an outer shell.

<Unit case>
The unit case 3 is composed of a first transmission case 11, a second transmission case 12, and a third transmission case 13. The first transmission case 11, the second transmission case 12, and the third transmission case 13 are made of an aluminum-based material and are cast by, for example, a die casting method.

The first transmission case 11, the second transmission case 12, and the third transmission case 13 are arranged in this order from the front side (engine 2 side). The first transmission case 11 and the second transmission case 12 are fastened with bolts 16, and the second transmission case 12 and the third transmission case 13 are fastened with bolts 17, whereby the first transmission case 11 and the second transmission are fastened. The case 12 and the third transmission case 13 are integrated.

<Torque converter>
The torque converter 4 is housed in the first transmission case 11. The torque converter 4 includes a front cover 21, a pump impeller 22, a turbine hub 23, a turbine runner 24, a lockup mechanism 25, and a stator 26.

The front cover 21 extends in a substantially disk shape around a rotation axis extending in the front-rear direction of the vehicle (vehicle body), and its outer peripheral end is on the opposite side to the engine 2 side (the stepless speed change mechanism 42 side described later). It has a shape that is bent to the side. The central portion of the front cover 21 bulges toward the front side. The crankshaft of the engine 2 is coupled to this bulging portion so that it cannot rotate relative to each other.

The pump impeller 22 is arranged behind the front cover 21. The outer peripheral end of the pump impeller 22 is connected to the outer peripheral end of the front cover 21 and is provided so as to be rotatable integrally with the front cover 21 around the rotation axis. A plurality of blades 27 are arranged radially on the inner surface of the pump impeller 22.

The turbine hub 23 is arranged between the front cover 21 and the pump impeller 22.

The turbine runner 24 is fixed to the turbine hub 23. A plurality of blades 28 are arranged in a radial pattern on the surface of the turbine runner 24 facing the pump impeller 22.

The lockup mechanism 25 includes a lockup piston 31 and a damper mechanism 32.

The lockup piston 31 has a substantially annular plate shape, and its inner peripheral end is fitted onto the turbine hub 23 and is located between the front cover 21 and the turbine runner 24. When the oil pressure of the engagement side oil chamber 33 on the turbine runner 24 side is higher than the oil pressure of the release side oil chamber 34 on the front cover 21 side with respect to the lockup piston 31, the lockup piston 31 is front-covered by the differential pressure. Move to the 21 side. Then, when the lockup piston 31 is pressed against the front cover 21, the pump impeller 22 and the turbine runner 24 are directly connected (lockup on). On the contrary, when the oil pressure of the release side oil chamber 34 is higher than the oil pressure of the engagement side oil chamber 33, the lockup piston 31 moves to the turbine runner 24 side due to the differential pressure. When the lockup piston 31 is separated from the front cover 21, the direct connection between the pump impeller 22 and the turbine runner 24 is released (lockup off).

The damper mechanism 32 is a mechanism for attenuating the vibration from the engine 2 when the pump impeller 22 and the turbine runner 24 are directly connected.

The stator 26 is arranged between the pump impeller 22 and the turbine runner 24.

When the pump impeller 22 is rotated by the engine torque in the lock-up-off state, an oil flow from the pump impeller 22 to the turbine runner 24 is generated. This oil flow is received by the blade 28 of the turbine runner 24, and the turbine runner 24 rotates. At this time, the amplification action of the torque converter 4 occurs, and a torque larger than the engine torque is generated in the turbine runner 24.

<CVT>
The CVT 5 is housed in the second transmission case 12 and the third transmission case 13. The CVT 5 includes an input shaft 41, a continuously variable transmission mechanism 42, an output shaft 43, and a reverse transmission mechanism 44. The transmission unit 1 is arranged vertically on the rear side of the engine 2 so that the input shaft 41 of the CVT 5 extends in the front-rear direction of the vehicle.

The input shaft 41 is formed in a hollow shaft and extends on the rotation axis of the torque converter 4. The front end portion of the input shaft 41 is inserted into the torque converter 4 and spline-fitted with the turbine hub 23.

In the following description, the direction in which the axis of the input shaft 41 extends is referred to as "axis direction". Further, the direction orthogonal to the axial direction, that is, the radial direction of the input shaft 41 is referred to as "shaft radial direction".

The rear end of the input shaft 41 is rotatably supported by a mechanical oil pump 45 arranged in the second transmission case 12. Specifically, the oil pump 45 cannot rotate relative to the pump case 46, the pump cover 47 joined to the pump case 46 from the rear side, the pump gear 48 arranged in the space inside the pump case 46, and the pump gear 48. It is equipped with a pump shaft 49 coupled to. The pump cover 47 is fixed to the second transmission case 12, and the space inside the pump case 46 is closed from the rear side. At the front end of the pump case 46, a recess 51 recessed in a substantially columnar shape is formed on the rear side. The rear end of the input shaft 41 is inserted into the recess 51 and can rotate to the pump case 46 via a radial bearing 52 interposed between the peripheral surface of the input shaft 41 and the inner peripheral surface of the recess 51. It is supported.

Further, a thrust bearing 53 is interposed between the rear end surface of the input shaft 41 and the bottom surface of the recess 51. As a result, the mechanical loss during rotation of the input shaft 41 is reduced.

The pump shaft 49 is provided so as to penetrate the pump case 46 and the pump cover 47. The pump shaft 49 extends forward from the pump case 46 and is inserted into the input shaft 41 with a gap between the pump shaft 49 and the inner peripheral surface thereof. The front end portion of the pump shaft 49 reaches the front cover 21 of the torque converter 4 and is connected to the central portion of the front cover 21 so as not to rotate relative to each other. As a result, when the front cover 21 is rotated by the power of the engine 2, the pump shaft 49 and the pump gear 48 are rotated integrally with the front cover 21, and oil is generated from the oil pump 45.

The continuously variable transmission mechanism 42 includes a primary shaft 54, a secondary shaft 55, a primary pulley 56, a secondary pulley 57, and a belt 58.

The primary shaft 54 and the secondary shaft 55 extend parallel to the input shaft 41 between the first transmission case 11 and the second transmission case 12, and are rotatably provided around the axis thereof.

The primary pulley 56 is arranged so as to face the primary fixed sheave 61 fixed to the primary shaft 54 with the belt 58 interposed therebetween, and is supported by the primary shaft 54 so as to be movable in the axial direction and non-relatively rotatable. It is equipped with a movable sheave 62. The primary movable sheave 62 is arranged on the front side with respect to the primary fixed sheave 61. A cylinder 63 is provided on the side opposite to the primary fixed sheave 61 side with respect to the primary movable sheave 62, that is, on the front side, and a hydraulic chamber (piston chamber) 64 is formed between the primary movable sheave 62 and the cylinder 63. ing.

The secondary pulley 57 is arranged so as to face the secondary fixed sheave 65 fixed to the secondary shaft 55 and the secondary fixed sheave 65 with the belt 58 interposed therebetween, and is supported by the secondary shaft 55 so as to be movable in the axial direction and non-relatively rotatable. It is equipped with a movable sheave 66. The secondary movable sheave 66 is arranged on the rear side with respect to the secondary fixed sheave 65. A piston 67 is provided on the side opposite to the secondary fixed sheave 65, that is, on the rear side of the secondary movable sheave 66, and a hydraulic chamber 68 is formed between the secondary movable sheave 66 and the piston 67.

The belt 58 is formed in an endless shape and is wound around the primary pulley 56 while being sandwiched between the primary fixed sheave 61 and the primary movable sheave 62, and is wound between the secondary fixed sheave 65 and the secondary movable sheave 66. It is wound around the secondary pulley 57 in a sandwiched state.

In the continuously variable transmission mechanism 42, the hydraulic pressure supplied to the hydraulic chambers 64 and 68 of the primary pulley 56 and the secondary pulley 57 is controlled, and the groove widths of the primary pulley 56 and the secondary pulley 57 are changed to change the belt. The gear ratio (the pulley ratio between the primary pulley 56 and the secondary pulley 57) is continuously and steplessly changed within a constant gear ratio range.

Specifically, when the belt gear ratio is reduced, the oil supply supplied to the hydraulic chamber 64 of the primary pulley 56 is increased. As a result, the primary movable sheave 62 of the primary pulley 56 moves to the primary fixed sheave 61 side, and the distance (groove width) between the primary fixed sheave 61 and the primary movable sheave 62 becomes smaller. Along with this, the winding diameter of the belt 58 with respect to the primary pulley 56 becomes large, and the distance (groove width) between the secondary fixed sheave 65 and the secondary movable sheave 66 of the secondary pulley 57 becomes large. As a result, the belt gear ratio becomes smaller.

When the belt gear ratio is increased, the oil supply to the hydraulic chamber 64 of the primary pulley 56 is reduced. As a result, the thrust of the secondary pulley 57 with respect to the belt 58 becomes larger than the thrust of the primary pulley 56 with respect to the belt 58, the distance between the secondary fixed sheave 65 and the secondary movable sheave 66 of the secondary pulley 57 becomes smaller, and the primary fixed sheave 61 The distance between the and the primary movable sheave 62 becomes large. As a result, the belt gear ratio becomes large.

A bias spring 69 is provided in the hydraulic chamber 68 of the secondary pulley 57. One end of the bias spring 69 elastically contacts the secondary movable sheave 66, and the other end elastically contacts the piston 67. The elastic force of the bias spring 69 urges the secondary movable sheave 66 and the piston 67 in a direction in which they are separated from each other. The secondary movable sheave 66 is subjected to the hydraulic pressure in the hydraulic chamber 68 and the urging force by the bias spring 69, and the belt 58 is subjected to the corresponding pinching pressure.

Further, the input shaft 41 is integrally formed with an input shaft gear 81 at the center in the axial direction. Correspondingly, the primary input gear 82 that meshes with the input shaft gear 81 is supported on the primary shaft 54 so as to be relatively rotatable. A forward clutch 83 is provided that allows / prohibits rotation of the primary input gear 82 with respect to the primary shaft 54 by utilizing the space between the input shaft gear 81 and the primary input gear 82 and the oil pump 45 that mesh with each other. There is. A part of the forward clutch 83 overlaps with the oil pump 45 in the axial direction (overlaps when viewed in the axial direction).

The forward clutch 83 includes a clutch drum 84, a clutch hub 85, and a clutch piston 86. The inner peripheral end of the clutch drum 84 is fixed to the primary shaft 54, extends from the primary shaft 54 in the shaft radial direction, and the outer peripheral end portion bends and extends toward the primary input gear 82, that is, the front side. The clutch hub 85 is formed integrally with the primary input gear 82, has a cylindrical shape extending rearward from the primary input gear 82, and is spaced from the inside in the axial direction with respect to the outer peripheral end of the clutch drum 84. Are facing each other. The clutch piston 86 is provided between the clutch drum 84 and the clutch hub 85 so as to be movable in the axial direction. The clutch piston 86 is in liquid-tight contact with the clutch drum 84, and a hydraulic chamber 87 to which the oil pressure acting on the clutch piston 86 is supplied is formed between the clutch drum 84 and the clutch piston 86. .. Further, the clutch piston 86 is elastically urged to the rear side by the return spring 88.

In a space sandwiched between the outer peripheral end of the clutch drum 84 and the clutch hub 85 in the axial direction, the clutch plate held by the clutch drum 84 and the clutch disc held by the clutch hub 85 are alternately arranged in the axial direction. There is. When the clutch piston 86 moves to the front side and presses the clutch plate from the rear side by the hydraulic pressure supplied to the hydraulic chamber 87, the clutch plate and the clutch disc are in pressure contact with each other, and the forward clutch 83 is engaged. The engagement of the forward clutch 83 prohibits the rotation of the primary input gear 82 with respect to the primary shaft 54, and when the primary input gear 82 rotates, the primary shaft 54 rotates integrally with the primary input gear 82. When the oil pressure is released from the engaged state of the forward clutch 83, the urging force of the return spring 88 moves the clutch piston 86 to the rear side, the pressure contact between the clutch disc and the clutch plate is released, and the forward clutch 83 is released. To be released. The release of the forward clutch 83 allows the rotation of the primary input gear 82 with respect to the primary shaft 54, and even if the primary input gear 82 rotates, the rotation is not transmitted to the primary shaft 54.

A secondary input gear 91 is supported on the secondary shaft 55 so as to be relatively rotatable. The secondary input gear 91 is arranged between the input shaft gear 81 and the oil pump 45 in the axial direction. Further, a reverse clutch 92 is provided that allows / prohibits the rotation of the secondary input gear 91 with respect to the secondary shaft 55 by utilizing the space between the secondary input gear 91 and the oil pump 45. A part of the reverse clutch 92 overlaps with the oil pump 45 in the axial direction (overlaps when viewed in the axial direction).

The reverse clutch 92 includes a clutch drum 93, a clutch hub 94, and a clutch piston 95. The inner peripheral end of the clutch drum 93 is fixed to the secondary shaft 55, extends from the secondary shaft 55 in the shaft radial direction, and the outer peripheral end portion bends and extends toward the secondary input gear 91, that is, the front side. The clutch hub 94 is formed integrally with the secondary input gear 91, has a cylindrical shape extending rearward from the secondary input gear 91, and is spaced from the inside in the axial direction with respect to the outer peripheral end of the clutch drum 93. Facing each other. The clutch piston 95 is provided between the clutch drum 93 and the clutch hub 94 so as to be movable in the axial direction. The clutch piston 95 is in liquid-tight contact with the clutch drum 93, and a hydraulic chamber 96 for supplying the oil pressure acting on the clutch piston 95 is formed between the clutch drum 93 and the clutch piston 95. .. Further, the clutch piston 95 is elastically urged to the rear side by the return spring 97.

In a space sandwiched between the outer peripheral end of the clutch drum 93 and the clutch hub 94 in the axial direction, the clutch plate held by the clutch drum 93 and the clutch disc held by the clutch hub 94 are alternately arranged in the axial direction. There is. When the clutch piston 95 moves to the front side and presses the clutch plate from the rear side by the hydraulic pressure supplied to the hydraulic chamber 96, the clutch plate and the clutch disc are in pressure contact with each other, and the reverse clutch 92 is engaged. The engagement of the reverse clutch 92 prohibits the rotation of the secondary input gear 91 with respect to the secondary shaft 55, and when the secondary input gear 91 rotates, the secondary shaft 55 rotates integrally with the secondary input gear 91. When the oil pressure is released from the engaged state of the reverse clutch 92, the clutch piston 95 moves to the rear side due to the urging force of the return spring 97, the pressure contact between the clutch disc and the clutch plate is released, and the reverse clutch 92 is released. To be released. By releasing the reverse clutch 92, the rotation of the secondary input gear 91 with respect to the secondary shaft 55 is allowed, and even if the secondary input gear 91 rotates, the rotation is not transmitted to the secondary shaft 55.

The output shaft 43 is arranged on the same axis as the input shaft 41 with a space behind the input shaft 41. In other words, the input shaft 41 and the output shaft 43 are arranged so as to have a common axis extending vertically along the front-rear direction of the vehicle in the front-rear direction at intervals in the axis direction. An output shaft gear 101 is integrally formed on the output shaft 43. Correspondingly, the secondary output gear 102 that meshes with the output shaft gear 101 is supported on the secondary shaft 55 so as to be relatively non-rotatable.

The reverse transmission mechanism 44 is a mechanism that transmits the power (rotation) of the input shaft 41 to the secondary input gear 91. The reverse transmission mechanism 44 includes a reverse idler shaft 103, a first reverse gear 104, and a second reverse gear 105. The reverse idler shaft 103 extends in the axial direction, straddles the first transmission case 11 and the second transmission case 12, and is rotatably supported by the first transmission case 11 and the second transmission case 12. The first reverse gear 104 is formed integrally with the reverse idler shaft 103 and meshes with the input shaft gear 81. The second reverse gear 105 is formed integrally with the reverse idler shaft 103 on the rear side of the first reverse gear 104 and meshes with the secondary input gear 91.

An adapter 111 is provided between the output shaft 43 and the primary shaft 54. The adapter 111 is, for example, a casting made of an aluminum alloy and cast by a die casting method. The adapter 111 extends in the axial direction between the output shaft 43 and the primary shaft 54. The upper end portion of the adapter 111 protrudes to the rear side, and a recess 112 recessed in a substantially columnar shape is formed on the front side of the protruding portion. The front end of the output shaft 43 is inserted into the recess 112. A radial bearing 113 is interposed between the peripheral surface of the output shaft 43 and the inner peripheral surface of the recess 112. The front end of the output shaft 43 is rotatably supported by the adapter 111 via a radial bearing 113. Further, the output shaft 43 is formed with an annular stepped surface along the shaft radial direction between the portion where the output shaft gear 101 is formed and the portion inserted into the recess 112. A thrust bearing 114 is interposed between the stepped surface and the adapter 111.

The adapter 111 is formed with a recess 115 that is recessed in a substantially columnar shape on the rear side. The rear end of the primary shaft 54 is inserted into the recess 115. A ball bearing 116 is interposed between the peripheral surface of the primary shaft 54 and the inner peripheral surface of the recess 115. The rear end of the primary shaft 54 is rotatably supported by the adapter 111 via ball bearings 116.

A bolt 117 is inserted into the lower end of the adapter 111 from the front side. Then, the adapter 111 is attached to the third transmission case 13 by the bolt 117.

<Power transmission path>
FIG. 2 is a skeleton diagram illustrating the configuration of CVT5.

When the vehicle moves forward, the forward clutch 83 is engaged and the reverse clutch 92 is released. The power input from the engine 2 to the input shaft 41 via the torque converter 4 is transmitted from the input shaft gear 81 to the primary shaft 54 via the primary input gear 82 by the engagement of the forward clutch 83. On the other hand, even if the power input to the input shaft 41 is transmitted from the input shaft gear 81 to the secondary input gear 91 and the secondary input gear 91 rotates, the secondary input gear 91 becomes the secondary shaft 55 due to the release of the reverse clutch 92. It slips with respect to (secondary shaft 55), and power is not transmitted to the secondary shaft 55.

The power transmitted to the primary shaft 54 is changed at a belt gear ratio corresponding to the pulley ratio of the primary pulley 56 and the secondary pulley 57, and is transmitted to the secondary shaft 55. Then, the power transmitted to the secondary shaft 55 is transmitted from the secondary output gear 102 to the output shaft 43 via the output shaft gear 101.

When the vehicle is moving backward, the forward clutch 83 is released and the reverse clutch 92 is engaged. The power input from the engine 2 to the input shaft 41 via the torque converter 4 is transmitted from the input shaft gear 81 to the secondary shaft 55 via the reverse transmission mechanism 44 and the secondary input gear 91 by the engagement of the reverse clutch 92. To. At this time, the secondary shaft 55 rotates in the direction opposite to that when the vehicle is moving forward. On the other hand, even if the power input to the input shaft 41 is transmitted from the input shaft gear 81 to the primary input gear 82 and the primary input gear 82 rotates, the primary input gear 82 becomes the primary shaft 54 due to the release of the forward clutch 83. It slips with respect to (primary shaft 54), and power is not transmitted to the primary shaft 54.

The power transmitted to the secondary shaft 55 is transmitted from the secondary output gear 102 to the output shaft 43 via the output shaft gear 101.

The power transmitted to the output shaft 43 is output from the output shaft 43 to the propeller shaft (not shown), and is transmitted from the propeller shaft to the left and right rear wheels via the rear differential gear (rear differential) and the drive shaft. To.

<Oil supply structure>
As shown in FIG. 1, a valve body 121 for controlling the supply of oil to each part of the transmission unit 1 is provided on the bottom of the second transmission case 12.

A strainer 122 is provided at the bottom of the second transmission case 12. The strainer 122 includes a filtration unit 123 arranged side by side with the valve body 121, and a pipe unit 124 extending from the filtration unit 123. The pipe portion 124 extends from the lower portion of the filtration portion 123 to the front side, extends while curving the lower side of the valve body 121 to the left side, and the tip portion thereof is arranged at the central portion of the second transmission case 12. The tube portion 124 is formed in a hollow tubular shape, and the inside thereof communicates with the inside of the filtration portion 123. Further, the lower surface of the tip portion of the pipe portion 124 is opened as a suction port 125 for sucking oil.

An oil pan 131 is fixed to the second transmission case 12 from below with a plurality of bolts 132. The tip of the pipe portion 124 of the strainer 122 is located at the center of the oil pan 131, and the suction port 125 at the tip of the pipe portion 124 faces the center of the oil pan 131.

A suction force is generated by the rotation of the pump gear 48 of the oil pump 45, and the suction force causes the oil accumulated in the oil pan 131 to be sucked into the pipe portion 124 from the suction port 125. The oil sucked into the pipe portion 124 flows in the pipe portion 124 toward the filter portion 123 and passes through the filter material provided in the filter portion 123. When the oil passes through the filter medium, the foreign matter contained in the oil is captured by the filter medium and the foreign matter is removed from the oil. The oil that has passed through the filter material is supplied to the valve body 121 via the oil pump 45. Then, oil is supplied from the valve body 121 to each part of the continuously variable transmission mechanism 42 or the like that requires oil supply as hydraulic oil or lubricating oil.

FIG. 3 is an enlarged cross-sectional view showing the vicinity of the secondary shaft 55 on the rear side of the reverse clutch 92.

The secondary shaft 55 is divided into a first secondary shaft 141 and a second secondary shaft 142. The first secondary shaft 141 is arranged on the front side of the second secondary shaft 142. As shown in FIG. 1, the secondary input gear 91 is supported by the first secondary shaft 141, and the secondary pulley 57 is supported by the second secondary shaft 142. As shown in FIG. 3, a connecting recess 143 having a shape recessed substantially in a columnar shape from the rear end surface is formed at the rear end of the first secondary shaft 141. The front end of the second secondary shaft 142 is inserted into the connecting recess 143.

In order to supply oil to the reverse clutch 92, an axial core oil passage 144 and an in-shaft oil passage 145 are formed in the first secondary shaft 141. The axial oil passage 144 extends on the axial center of the first secondary shaft 141 and is opened at the rear end surface (bottom surface of the connecting recess 143) of the first secondary shaft 141. Further, a distribution oil passage 146 is formed in the first secondary shaft 141. One end of the distribution oil passage 146 is connected to the axial core oil passage 144 and communicates with the axial core oil passage 144. The other end of the distribution oil passage 146 is open on the outer peripheral surface of the first secondary shaft 141 at a position facing the return spring 97 in the shaft radial direction.

On the other hand, the front end of the second secondary shaft 142 has a substantially cylindrical shape having an outer diameter corresponding to the inner diameter of the connecting recess 143 as a connecting convex portion 151 inserted into the connecting recess 143 of the first secondary shaft 141. It is formed. The front side portion of the connection convex portion 151 is spline-fitted with the inner peripheral surface of the connection recess 143, and the rear side portion is fitted with an inlay in a state where there is no gap and the center is aligned with the inner peripheral surface of the connection recess 143. doing. The tip surface of the connecting convex portion 151 is separated from the bottom surface of the connecting concave portion 143 in the axial direction, and a space 152 is formed between the bottom surface of the connecting concave portion 143 and the tip surface of the connecting convex portion 151.

The second transmission case 12 is formed with a wall portion 153 extending in the vertical direction between the reverse clutch 92 and the secondary pulley 57 (see FIG. 1). The wall portion 153 is formed with a shaft insertion portion 154 through which the first secondary shaft 141 is inserted. The inner peripheral surface of the shaft insertion portion 154 is formed as a cylindrical surface.

Inside the shaft insertion portion 154, a cylindrical sleeve 155 is provided in a state in which the outer peripheral surface thereof is in close contact with the inner peripheral surface of the shaft insertion portion 154. The sleeve 155 is fixed to the shaft insertion portion 154 by the lock plate 156. The first secondary shaft 141 is inserted into the shaft insertion portion 154 (sleeve 155) so that the sleeve 155 is fitted so as to straddle the connection recess 143 and the portion on the front side thereof.

FIG. 4 is a perspective view of the sleeve 155 and the lock plate 156, showing a state in which the sleeve 155 and the lock plate 156 are viewed obliquely from the rear.

The sleeve 155 is formed by centerless processing a cylindrical material made of the same aluminum material as the second transmission case 12, and in particular, the outer diameter dimension of the outer peripheral surface 157 that is in close contact with the inner peripheral surface of the shaft insertion portion 154 is high. It is controlled with precision. The surface of the sleeve 155 including the inner peripheral surface 158 is subjected to an alumite treatment (anodizing treatment), which is an example of a hard treatment.

At the front edge of the sleeve 155, a stepped portion 159 is formed over the entire circumference by digging down one step from the outer peripheral surface 157. The rear edge of the sleeve 155 is chamfered so that the outer diameter becomes smaller toward the rear side, and a rectangular notch 161 in a plan view penetrates the sleeve 155 in the thickness direction in the chamfered portion. Is formed.

The lock plate 156 is made of the same aluminum-based material as the sleeve 155, and is formed in a shape that fits into the notch 161 with almost no gap. That is, the lock plate 156 is formed in a plate shape having a thickness substantially equal to the front-rear dimension of the notch 161 and a width substantially equal to the left-right dimension of the notch 161. The lock plate 156 extends upward from the notch 161 in a state of being fitted in the notch 161. The upper end edge of the lock plate 156 is formed in a semicircular shape, and the lower end edge is formed in an arc shape along the inner peripheral surface of the sleeve 155.

As shown in FIG. 3, a retaining 162 that protrudes inward in the radial direction is formed at the front end of the shaft insertion portion 154 over the entire circumference. In the sleeve 155, the lock plate 156 is fitted with the step portion 159, the lock plate 156 fitted in the notch 161 is in contact with the rear end surface of the shaft insertion portion 154, and the lock plate 156 is bolted 163 to the shaft insertion portion 154. By being fixed to, it is fixed to the shaft insertion portion 154 in a state of being sandwiched between the lock plate 156 and the retaining 162.

Further, a plurality of oil passages through which oil delivered from the valve body 121 flows are formed in the wall portion 153. In this oil passage, for example, a reverse clutch lubricating oil passage 171 through which oil supplied as lubricating oil to the reverse clutch 92 flows, and a reverse clutch hydraulic oil passage 172 through which oil supplied as hydraulic oil to the reverse clutch 92 flows. And are included.

The reverse clutch lubricating oil passage 171 and the reverse clutch hydraulic oil passage 172 extend from the valve body 121 to the shaft insertion portion 154 and are opened on the inner surface of the shaft insertion portion 154. The sleeve 155 is formed with an oil hole 173 penetrating the reverse clutch lubricating oil passage 171 at a position overlapping the open end (position facing the shaft radial direction) of the reverse clutch lubricating oil passage 171. Further, the sleeve 155 is formed with an oil hole 174 communicating with the reverse clutch hydraulic oil passage 172 penetrating at a position overlapping the open end of the reverse clutch hydraulic oil passage 172.

Oil grooves 175 and 176 are formed on the outer peripheral surface of the first secondary shaft 141 at positions overlapping the oil holes 173 and 174, respectively, over the entire circumference. Further, on the outer peripheral surface of the first secondary shaft 141, annular seal rings 177, 178, and 179 are embedded between the oil grooves 175 and 176, on the rear side of the oil groove 175 and on the front side of the oil groove 176, respectively. .. The seal rings 177, 178, 179 are in liquid-tight contact with the inner peripheral surface of the sleeve 155 to prevent oil from leaking from the space sandwiched between the seal rings 177, 178, 179.

The first secondary shaft 141 is formed with a communication oil passage 181 that communicates the space 152 in the connection recess 143 and the oil groove 175. Further, one end of the in-shaft oil passage 145 is connected to the oil groove 176, and the oil groove 176 communicates with the in-shaft oil passage 145. The other end of the in-shaft oil passage 145 is connected to the hydraulic chamber 96 of the reverse clutch 92.

With this configuration, the oil delivered from the valve body 121 to the reverse clutch lubricating oil passage 171 flows into the oil groove 175 of the first secondary shaft 141 from the reverse clutch lubricating oil passage 171 through the oil hole 173 of the sleeve 155. Then, oil flows into the space 152 from the oil groove 175 through the communication oil passage 181 and the oil collects in the space 152. The oil accumulated in the space 152 flows into the axial oil passage 144 and is supplied from the axial oil passage 144 to the reverse clutch 92 via the distribution oil passage 146. As a result, the reverse clutch 92 is cooled and lubricated with oil.

Further, the oil delivered from the valve body 121 to the reverse clutch hydraulic oil passage 172 flows into the oil groove 176 of the first secondary shaft 141 from the reverse clutch hydraulic oil passage 172 through the oil hole 174 of the sleeve 155. Then, it is supplied from the oil groove 176 to the hydraulic chamber 96 of the reverse clutch 92 via the in-shaft oil passage 145.

<Effect>
As described above, the cylindrical sleeve 155 is interposed between the first secondary shaft 141 and the shaft insertion portion 154 through which the first secondary shaft 141 is rotatably inserted. Since both the shaft insertion portion 154 and the sleeve 155 are made of an aluminum-based material, it is possible to suppress the occurrence of a difference in thermal expansion between them. Therefore, the inner peripheral surface of the shaft insertion portion 154 and the outer peripheral surface 157 of the sleeve 155 can be formed to have substantially the same diameter, and the sleeve 155 can be inserted into the shaft insertion portion 154 without being press-fitted. As a result, the workability when assembling the sleeve 155 to the shaft insertion portion 154, that is, the assembling property between the shaft insertion portion 154 and the sleeve 155 is improved. Further, the rigidity (thickness) of the shaft insertion portion 154 can be reduced as compared with the configuration in which the sleeve 155 is press-fitted into the shaft insertion portion 154. As a result, the mass of the shaft insertion portion 154 can be reduced, and the mass of the transmission unit 1 can be reduced.

Further, since the sleeve 155 has a cylindrical shape, centerless processing can be adopted for manufacturing the sleeve 155, and by adopting the centerless processing, the dimensional accuracy of the sleeve 155 can be improved. If the dimensional accuracy of the sleeve 155 is high, it is possible to eliminate the gap between the inner peripheral surface of the shaft insertion portion 154 and the outer peripheral surface 157 of the sleeve 155, and it is possible to reduce oil leakage from between them.

In order to provide the sleeve 155 so that it cannot rotate relative to the shaft insertion portion 154, the transmission unit 1 further includes a lock plate 156 that is connected to the sleeve 155 so that it cannot rotate relative to the shaft insertion portion 154 and is fixed to the shaft insertion portion 154. There is. The lock plate 156 is made of an aluminum-based material. As a result, it is possible to suppress the occurrence of a thermal expansion difference between the lock plate 156 and the shaft insertion portion 154 and the sleeve 155, and the reverse clutch lubricating oil passage 171 and the sleeve 155 formed in the shaft insertion portion 154 are formed. It is possible to prevent the relative position of the oil hole 173 and the relative position of the reverse clutch hydraulic oil passage 172 formed in the shaft insertion portion 154 and the oil hole 174 formed in the sleeve 155 from being displaced.

<Modification example>
Although one embodiment of the present invention has been described above, the present invention can also be implemented in other embodiments.

For example, in the above-described embodiment, the transmission unit 1 is arranged vertically on the rear side of the engine 2 so that the input shaft 41 of the CVT 5 extends in the front-rear direction of the vehicle. However, the present invention is not limited to this, and the present invention can also be applied to a transmission unit that is horizontally placed on the left side or the right side of the engine 2 so that the input shaft of the CVT extends in the left-right direction of the vehicle.

Further, the power transmission method of the continuously variable transmission mechanism 42 is not limited to the belt type, and may be a chain type or a toroidal type.

Further, the speed change mechanism provided in the speed change unit 1 is not limited to the stepless speed change mechanism 42, and may be a stepped speed change mechanism.

In addition, various design changes can be made to the above-mentioned configuration within the scope of the matters described in the claims.

1: Transmission unit (transmission)
55: Secondary axis (rotation axis)
141: 1st secondary axis (rotational axis)
154: Shaft insertion part 155: Sleeve (cylindrical member)
156: Lock plate 158: Inner peripheral surface 171: Reverse clutch Lubricating oil passage (oil passage)
172: Reverse clutch hydraulic oil passage (oil passage)
173,174: Oil holes 177,178,179: Seal ring

Claims (3)

Rotation axis and
A shaft insertion portion having a cylindrical inner peripheral surface through which the rotating shaft is rotatably inserted,
A cylindrical cylindrical member interposed between the rotating shaft and the shaft insertion portion, and
A seal ring fixed to the outer peripheral surface of the rotating shaft and rubbed against the inner peripheral surface of the cylindrical member as the rotating shaft rotates.
The shaft insertion portion and the cylindrical member are made of an aluminum-based material.
A transmission in which at least the inner peripheral surface of the cylindrical member is hardened. The transmission according to claim 1, further comprising a lock plate that is non-rotatably connected to the cylindrical member and fixed to the shaft insertion portion. An oil passage opened on the inner peripheral surface of the shaft insertion portion is formed.
The position of the cylindrical member facing the open end of the oil passage in the axial direction of the shaft in a state where the cylindrical member is provided by the lock plate so as not to rotate relative to the shaft insertion portion. An oil hole communicating with the oil passage is formed in the oil hole.
The transmission according to claim 2, wherein the lock plate is made of an aluminum-based material.

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