JP2021085516A - transmission - Google Patents

Abstract

To provide a transmission capable of simplifying an oil path structure in a valve body.SOLUTION: When driving an oil pump, oil received in an oil pan is sucked in a strainer, and the sucked oil is filtered by the strainer. The oil after filtering flows in an oil path 162 after filtering toward the oil pump, and is supplied to a valve body through the oil pump. The valve body is equipped with a secondary regulator valve adjusting first oil pressure and generating second oil pressure. The excessive oil due to the pressure adjustment by the secondary regulator valve is discharged to the oil path 162 after filtering through a return oil path 161. The return oil path 161 and the oil path 162 after filtering are formed in a second transmission case 12 of a transmission unit.SELECTED DRAWING: Figure 4

Description

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

Conventionally, in a transmission such as a CVT (Continuously Variable Transmission), a valve body for controlling the supply of oil to each part is arranged at the bottom of a case forming an outer shell, and the case is covered with oil. The oil pan that receives the valve is bolted from the underside of the valve body. A strainer for filtering the oil sucked up from the oil pan is arranged between the valve body and the oil pan.

The case is equipped with an oil pump that is driven by the power of an engine or the like. When the oil pump is driven, the oil accumulated in the oil pan is sucked up from the suction port formed in the strainer. The oil sucked up by the strainer passes through the filter material provided in the strainer, and then is supplied to the valve body via the inside of the oil pump.

JP-A-2017-180711

The valve body is provided with a primary regulator valve that regulates the discharge pressure of the oil pump to the line pressure, a secondary regulator valve that regulates the oil pressure output from the primary regulator valve, and outputs a constant pressure.

The excess oil due to the pressure adjustment at the secondary regulator valve does not come out of the oil passage from the strainer via the oil pump, primary regulator valve and secondary regulator valve, and foreign matter such as metal powder is not mixed. It is preferable that the oil after filtration by the strainer flows from the secondary regulator valve through the return oil passage to the oil passage after filtration. For this purpose, a return oil passage and a post-filtration oil passage may be formed in the valve body, but in such a case, the oil passage configuration in the valve body becomes complicated and the valve body becomes large.

An object of the present invention is to provide a transmission capable of simplifying the oil passage configuration in the valve body.

In order to achieve the above object, the transmission according to the present invention includes a case forming an outer shell, an oil pump provided in the case, an oil pan attached to the case from below to receive oil, and an oil pump. At the time of driving, the oil received in the oil pan is sucked from the suction port, and the strainer that filters the sucked oil and the oil that is supplied from the strainer via the oil pump are supplied, and the first oil pressure is adjusted to the second oil pressure. A valve body equipped with a pressure regulating valve, and a case, a post-filtered oil passage through which oil after filtration by a strainer flows toward an oil pump, and oil surplus due to pressure regulation by the pressure regulating valve. Is formed with a return oil passage for discharging the oil to the oil passage after filtration.

According to this configuration, when the oil pump is driven, the oil received in the oil pan is sucked into the suction port of the strainer, and the sucked oil is filtered by the strainer. The filtered oil flows through the filtered oil passage toward the oil pump and is supplied to the valve body via the oil pump. The valve body is equipped with a pressure regulating valve that regulates the pressure of the first hydraulic pressure to generate the second hydraulic pressure, and the excess oil due to the pressure regulation by the pressure regulating valve is filtered through the return oil passage and then the oil passage. Is discharged to. Since the excess oil due to the pressure adjustment by the pressure adjustment valve is not mixed with foreign substances such as metal powder, there is no problem even if it is returned from the return oil passage to the oil passage after filtration without passing through the strainer. In addition, excess pressure oil is discharged from the return oil passage to the oil passage after filtration, which assists the suction action of the oil pump, so that the power required to drive the oil pump can be reduced, and the oil pump is the power of the engine. When driven by, the load on the engine is reduced, so that fuel efficiency can be improved.

The post-filtration oil passage and the return oil passage are formed in the case of the transmission. As a result, it is possible to eliminate the need to form the oil passage and the return oil passage after filtration in the valve body, so that the oil passage configuration in the valve body can be simplified and the valve body can be downsized. be able to.

In the case, a partition wall is formed between the oil passage after filtration and the return oil passage, and communication holes are formed so as to straddle both sides of the partition wall. It may communicate with the return oil passage.

According to the present invention, the oil passage configuration in the valve body can be simplified, and the valve body can be miniaturized.

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 a circuit diagram which shows a part structure of a hydraulic circuit. It is the figure which looked at the 2nd transmission case from the lower side. It is the figure which looked at the intake oil passage shown in FIG. 4 from the front side.

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, for example, an aluminum alloy and are cast by 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 extends parallel to the input shaft 41 at a position separated from the input shaft 41 to the lower right when viewed from the rear side of the vehicle between the first transmission case 11 and the second transmission case 12. It is rotatably provided around its axis.

The secondary shaft 55 is parallel to the input shaft 41 at a position separated from the axis of the input shaft 41 to the upper left when viewed from the rear side of the vehicle between the first transmission case 11 and the second transmission case 12. It extends and is rotatably provided around its axis.

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 a circuit diagram showing a partial configuration of a hydraulic circuit.

The hydraulic circuit for supplying hydraulic pressure to each part of the transmission unit 1 includes a primary regulator valve 141 and a secondary regulator valve 142. The primary regulator valve 141 and the secondary regulator valve 142 are provided on the valve body 121.

The primary regulator valve 141 is a valve for adjusting the discharge pressure of the oil pump 45 to the line pressure. Specifically, the lead-in oil passage 144 is branched and connected to the line pressure oil passage 143 to which the oil discharged from the oil pump 45 is supplied. The lead-in oil passage 144 is connected to the input port 145 of the primary regulator valve 141. A solenoid pressure, which is an output pressure of a linear solenoid valve (not shown), is input to the signal port 146 of the primary regulator valve 141. In the primary regulator valve 141, the spool 147 moves according to the solenoid pressure and the oil pressure of the line pressure oil passage 143, and the opening degree of the input port 145 changes according to the position of the spool 147. As a result, the oil pressure input from the line pressure oil passage 143 to the input port 145 through the lead-in oil passage 144 changes, and the oil pressure of the line pressure oil passage 143 becomes a line pressure proportional to the solenoid pressure input to the input port 145. The pressure is adjusted.

The hydraulic pressure input to the input port 145 is output from the output port 148 of the primary regulator valve 141 and input to the signal port 151 and the input port 152 of the secondary regulator valve 142. When the oil pressure input to the signal port 151 rises from a constant pressure, the spool 153 of the secondary regulator valve 142 moves against the elastic force of the spring 154, and the input port 152 communicates with the return port 155 of the secondary regulator valve 142. The area increases and the oil flowing from the input port 152 to the return port 155 increases. On the contrary, when the oil pressure input to the signal port 151 drops from a constant pressure, the spool 153 moves due to the elastic force of the spring 154, and the communication area between the input port 152 and the return port 155 of the secondary regulator valve 142 is reduced. The amount of oil flowing from the input port 152 to the return port 155 is reduced. As a result, the oil pressure output from the output ports 156 and 157 of the secondary regulator valve 142 is kept constant. That is, the secondary regulator valve 142 is a pressure adjusting valve that regulates the oil pressure (first oil pressure) input to the input port 152 and outputs a constant oil pressure (second oil pressure) from the output ports 156 and 157.

The oil output from the return port 155, that is, the surplus oil generated by the pressure regulation, is discharged through the return oil passage 161 to the filtered oil passage 162 in which the oil filtered by the strainer 122 flows toward the oil pump 45.

FIG. 4 is a view of the second transmission case 12 as viewed from below.

The second transmission case 12 is formed with a suction oil passage 164 that communicates with the suction port 163 of the oil pump 45. The suction oil passage 164 extends in the vertical direction and is opened on the lower surface of the second transmission case 12. A rib-shaped partition wall 165 is formed in the suction oil passage 164, and the suction oil passage 164 is divided into a left side portion and a right side portion in the left-right direction by the rib-shaped partition wall 165. Then, the return oil passage 161 is formed by the left side portion of the suction oil passage 164, and the post-filtration oil passage 162 is formed by the right side portion.

FIG. 5 is a view of the suction oil passage 164 as viewed from the front side.

Further, the second transmission case 12 is formed with circular communication holes 166 so as to straddle both sides of the partition wall 165. The communication hole 166 may be formed by drilling, or may be formed by casting in the casting process of the second transmission case 12. The return oil passage 161 and the filtered oil passage 162 communicate with each other through the communication hole 166.

The communication hole 166 is liquidtightly closed by a plate (not shown) that comes into contact with the communication hole 166 from the front side.

<Effect>
As described above, when the oil pump 45 is driven, the oil received in the oil pan 131 is sucked into the suction port 125 of the strainer 122, and the sucked oil is filtered by the strainer 122. The filtered oil flows through the filtered oil passage 162 toward the oil pump 45 and is supplied to the valve body 121 via the oil pump 45. The valve body 121 is provided with a secondary regulator valve 142 that regulates the first hydraulic pressure to generate a second hydraulic pressure, and the excess oil due to the pressure regulation by the secondary regulator valve 142 passes through the return oil passage 161. After filtration, it is discharged to the oil passage 162. Since the excess oil due to the pressure regulation by the secondary regulator valve 142 is not mixed with foreign substances such as metal powder, there is a problem even if it is returned from the return oil passage 161 to the oil passage 162 after filtration without passing through the strainer 122. There is no. Further, since the excess pressure oil is discharged from the return oil passage 161 to the oil passage 162 after filtration, the suction action by the oil pump 45 is assisted, so that the power required for driving the oil pump 45 can be reduced, and the engine 2 can be reduced. Since the load on the oil is reduced, the fuel efficiency can be improved.

The filtered oil passage 162 and the return oil passage 161 are formed in the second transmission case 12 of the transmission unit 1. As a result, it is possible to eliminate the need to form the oil passage 162 and the return oil passage 161 after filtration in the valve body 121, so that the oil passage configuration in the valve body 121 can be simplified, and the valve body 121 can be simplified. Can be miniaturized.

<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)
5: CVT (transmission)
12: 2nd transmission case (case)
45: Oil pump 121: Valve body 122: Strainer 125: Suction port 131: Oil pan 142: Secondary regulator valve (pressure regulating valve)
161: Return oil passage 162: Oil passage after filtration 165: Partition wall 166: Communication hole

Claims (2)

The case that forms the outer shell and
The oil pump provided in the case and
An oil pan that is attached to the case from below and receives oil,
When the oil pump is driven, a strainer that sucks the oil received in the oil pan from the suction port and filters the sucked oil, and
A valve body including a pressure regulating valve in which oil is supplied from the strainer via the oil pump to regulate the first oil pressure to generate a second oil pressure.
In the case, the oil after filtration by the strainer flows toward the oil pump, and the oil surplus due to the pressure adjustment by the pressure adjusting valve is discharged to the oil passage after filtration. A transmission in which a return oil passage is formed. In the case, a partition wall is formed between the filtered oil passage and the return oil passage, and communication holes are formed so as to straddle both sides of the partition wall.
The transmission according to claim 1, wherein the filtered oil passage and the return oil passage communicate with each other through the communication hole.

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