JP7408384B2 - power transmission device - Google Patents

Description

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

In a vehicle equipped with an engine as a drive source for driving, power from the engine is transmitted to drive wheels via a transmission. Engines can be mounted either vertically, in which the crankshaft is oriented vertically with respect to the longitudinal direction of the vehicle, or horizontally, in which the crankshaft is oriented horizontally. In vehicles with a FF (Front-engine Front-wheel-drive) layout, for example, the engine is mounted horizontally in order to increase the cabin length by reducing the longitudinal size of the engine compartment. It is often done. On the other hand, in vehicles with an FR (Front-engine Rear-wheel-drive) layout, the engine is placed vertically to make it easier to transmit power to the rear wheels, which are the driving wheels. It may be installed.

2. Description of the Related Art Vertical transmissions have already been provided as transmissions for vehicles in which engines are mounted vertically. A vertical transmission is arranged such that an input shaft into which engine power is input is oriented vertically with respect to the longitudinal direction of the vehicle body. In an example of a vertical transmission, an output shaft that outputs power to a propeller shaft is arranged on the same axis as an input shaft. Power input to the input shaft is transmitted to the output shaft via the transmission mechanism, from the output shaft to the propeller shaft, and from the propeller shaft to the left and right rear wheels via the rear differential gear and drive shaft. .

Japanese Patent Application Publication No. 2012-192855

The end of the propeller shaft on the output shaft side is formed into a cylindrical shape, and a spline is formed on the inner circumferential surface thereof. On the other hand, a spline is formed on the outer circumferential surface of the output shaft at its end on the propeller shaft side. The cylindrical end of the propeller shaft is inserted into a case into which the output shaft is inserted, and is rotatably supported by the case via a bush. is coupled to the output shaft in a relatively non-rotatable manner.

Since friction occurs between the bushing and the propeller shaft, it is necessary to supply oil for lubrication to the bushing. As a configuration for supplying oil to the bushing, a configuration in which an oil passage from the valve body to the bushing is provided in the case for controlling the supply of hydraulic pressure to various parts can be considered. However, with this configuration, oil is always supplied to the bush from the same position in the circumferential direction, resulting in variations in the amount of lubrication in the circumferential direction of the bush.

An object of the present invention is to provide a power transmission device that can improve the performance of lubricating a bush.

In order to achieve the above object, the power transmission device according to the present invention is a power transmission device mounted on a vehicle, and includes a case forming an outer shell, an adapter provided in the case and supported by the case, The case includes an output shaft that is rotatably supported by the adapter, and a propeller shaft that is coupled to the output shaft and that transmits power from the output shaft, and the case extends in the axial direction of the output shaft and has openings on both sides in the axial direction. A cylindrical part is formed, the output shaft is inserted into the cylindrical part from one side in the axial direction, and the propeller shaft is inserted into the cylindrical part from the other side in the axial direction, and the output shaft is inserted into the cylindrical part from the other side in the axial direction. The output shaft is rotatably supported by the cylindrical part via a bush interposed between the output shaft and the output shaft, and includes an axial oil passage extending along the axis of the output shaft and supplied with oil; A communicating oil passage is formed that communicates with the axial oil passage, is open at the circumferential surface of the output shaft, and communicates with the space between the output shaft and the cylindrical portion.

According to this configuration, the adapter is provided within the case forming the outer shell, and the output shaft is rotatably supported by the adapter. A cylindrical portion extending in the axial direction of the output shaft is formed in the case. The output shaft is inserted into the cylindrical portion from one side in the axial direction, and the propeller shaft is inserted from the other side in the axial direction. The propeller shaft is rotatably held in the cylindrical portion via a bush interposed between the propeller shaft and the inner circumferential surface of the cylindrical portion.

An axial oil passage and a communicating oil passage are formed in the output shaft. The axial oil passage extends on the axis of the output shaft. The communication oil passage communicates with the axial oil passage, and is opened at the circumferential surface of the output shaft and communicates with the space between the output shaft and the cylindrical portion.

As a result, when oil is supplied to the axial oil passage, the oil flows from the axial oil passage into the communication oil passage, and the oil is released into the space between the propeller shaft and the cylindrical part through the axial oil passage. Ru. When the output shaft rotates, oil is radially released around the output shaft from the communication oil passage. Therefore, oil can be evenly supplied to the entire circumference of the bush. As a result, the performance of lubricating the bushing is improved.

The communication oil passage is provided on one side in the axial direction with respect to the bush, and the power transmission device has one axial side on the front side of the vehicle and the other axial side on the rear side of the vehicle, and connects to the shaft of the output shaft. It is preferable that the center be mounted on the vehicle so that the center is tilted backwards.

With this configuration, even if the vehicle is tilted forward on a downhill slope, the oil released from the communication oil passage can be supplied to the bush. Therefore, it is possible to further improve the performance of lubricating the bush.

The output shaft is rotatably supported by the case via a bearing disposed on the other side of the adapter in the axial direction and on one side of the axial direction of the cylindrical part. One end may be bent toward the output shaft to provide a dam between the space in which the bush is placed and the bearing.

With this configuration, oil released from the communication oil passage can be stored in the space where the bush is arranged. Therefore, oil can be more effectively supplied to the bush, and the performance of lubricating the bush can be further improved. Additionally, oil overflowing over the weir is supplied to the bearings that support the output shaft. Therefore, the bearing can be lubricated with oil. Moreover, the amount of oil supplied to the bearing can be adjusted by adjusting the height of the weir, and the balance between lubrication of the bush and lubrication of the bearing can be easily adjusted.

According to the present invention, it is possible to improve the performance of lubricating the bush.

FIG. 1 is a sectional view showing the configuration of a transmission unit according to an embodiment of the present invention. FIG. 2 is a skeleton diagram schematically showing the configuration of a CVT. FIG. 2 is a cross-sectional view showing the vicinity of the output shaft on a larger scale than in FIG. 1;

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

<Transmission unit>
FIG. 1 is a sectional view showing the configuration of a transmission unit 1 according to an embodiment of the present invention. Note that in the cross-sectional views shown in FIG. 1 and subsequent figures, hatching representing the cross-section is omitted.

The transmission unit 1 is a unit that is mounted on a vehicle and changes the speed of power generated by an engine 2 (E/G) 2 as a drive source for driving. The vehicle uses an FR (front engine, rear drive) layout.

The engine 2 is, for example, a three-cylinder, four-stroke engine, and is mounted vertically with the crankshaft oriented vertically with respect to the longitudinal direction of the vehicle body. The number of cylinders in the engine 2 is not limited to three, but may be four or more, or two or less. Further, the number of strokes of the engine 2 is not limited to four strokes, but may be two strokes.

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

<Unit case>
The unit case 3 is composed of three parts: 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 die-casting.

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, and the second transmission case 12 and third transmission case 13 are fastened with bolts 17, so that the first transmission case 11 and the second transmission case 12 and third transmission case 13 are integrated.

<Torque converter>
Torque converter 4 is housed within 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 rotational axis extending in the longitudinal direction of the vehicle (vehicle body), and its outer peripheral end is on the side opposite to the engine 2 side (on the side of the continuously variable transmission mechanism 42 described later). It has a shape that is bent to the side. The center of the front cover 21 bulges forward. The crankshaft of the engine 2 is coupled to this bulged portion in a relatively non-rotatable manner.

The pump impeller 22 is arranged on the rear side of the front cover 21. The outer circumferential end of the pump impeller 22 is connected to the outer circumferential end of the front cover 21, and is provided so as to be rotatable together with the front cover 21 about the rotation axis. A plurality of blades 27 are arranged radially on the inner surface of the pump impeller 22 .

Turbine hub 23 is arranged between front cover 21 and pump impeller 22.

Turbine runner 24 is fixed to turbine hub 23. A plurality of blades 28 are arranged radially 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, an inner peripheral end thereof is fitted onto the turbine hub 23, and is located between the front cover 21 and the turbine runner 24. When the oil pressure in the engagement side oil chamber 33 on the turbine runner 24 side with respect to the lockup piston 31 is higher than the oil pressure in the release side oil chamber 34 on the front cover 21 side, the lockup piston 31 moves toward the front cover due to the differential pressure. Move to the 21 side. When the lockup piston 31 is pressed against the front cover 21, the pump impeller 22 and the turbine runner 24 are directly coupled (locked on). Conversely, when the oil pressure in the release side oil chamber 34 is higher than the oil pressure in the engagement side oil chamber 33, the lockup piston 31 moves toward the turbine runner 24 due to the pressure difference. When the lock-up piston 31 is separated from the front cover 21, the direct connection between the pump impeller 22 and the turbine runner 24 is released (lock-up off).

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

Stator 26 is arranged between pump impeller 22 and turbine runner 24.

When the pump impeller 22 rotates due to engine torque in the lock-up off state, oil flows from the pump impeller 22 toward the turbine runner 24. This oil flow is received by the blades 28 of the turbine runner 24, causing the turbine runner 24 to rotate. At this time, the amplification effect of the torque converter 4 occurs, and a torque larger than the engine torque is generated in the turbine runner 24.

<CVT>
CVT 5 is housed within second transmission case 12 and 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 disposed on the rear side of the engine 2 so that the input shaft 41 of the CVT 5 is vertically oriented so as to extend in the longitudinal direction of the vehicle, and the input shaft 41 is arranged to be inclined downward toward the rear.

Input shaft 41 is formed into a hollow shaft and extends on the rotational axis of torque converter 4 . A front end portion of the input shaft 41 is inserted into the torque converter 4 and is spline-fitted to the turbine hub 23.

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

A rear end portion of the input shaft 41 is rotatably supported by a mechanical oil pump 45 disposed within the second transmission case 12. Specifically, the oil pump 45 includes a pump case 46, a pump cover 47 joined to the pump case 46 from the rear side, a pump gear 48 disposed in a space inside the pump case 46, and a pump gear 48 that cannot rotate relative to the pump gear 48. A pump shaft 49 coupled to the pump shaft 49 is provided. The pump cover 47 is fixed to the second transmission case 12 and closes off the space inside the pump case 46 from the rear side. A bearing recess 51 is formed at the front end of the pump case 46 and is open toward the front and recessed toward the rear in a substantially cylindrical shape. The rear end of the input shaft 41 is inserted into the bearing recess 51 and rotated by the pump case 46 via a ball bearing 52 interposed between the peripheral surface of the input shaft 41 and the inner peripheral surface of the bearing recess 51. Possibly supported. In other words, the ball bearing 52 is fitted onto the rear end of the input shaft 41 , and the ball bearing 52 is fitted into the bearing recess 51 , so that the rear end of the input shaft 41 is connected to the pump via the ball bearing 52 . It is rotatably supported by a case 46.

The pump shaft 49 is provided 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 input shaft 41 and the inner peripheral surface thereof. The front end of the pump shaft 49 reaches the front cover 21 of the torque converter 4 and is connected to the center of the front cover 21 so as to be relatively non-rotatable. 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 together with the front cover 21, and oil pressure 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 their axes.

The primary pulley 56 includes a primary fixed sheave 61 fixed to the primary shaft 54, and a primary disposed opposite to the primary fixed sheave 61 with a belt 58 interposed therebetween, and supported by the primary shaft 54 so as to be movable in the axial direction and relatively non-rotatable. A movable sheave 62 is provided. 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 includes a secondary fixed sheave 65 fixed to the secondary shaft 55 and a secondary fixed sheave 65 that is disposed opposite to the secondary fixed sheave 65 with a belt 58 interposed therebetween, and is supported by the secondary shaft 55 so as to be movable in the axial direction and non-rotatable relative to the secondary shaft 55. A movable sheave 66 is provided. 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 opposite side of the secondary movable sheave 66 from the secondary fixed sheave 65, that is, on the rear side, and a hydraulic chamber 68 is formed between the secondary movable sheave 66 and the piston 67.

The belt 58 is formed into 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 also wound between the secondary fixed sheave 65 and the secondary movable sheave 66. It is wound around the secondary pulley 57 in a pinched state.

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

Specifically, when the belt transmission ratio is decreased, the hydraulic pressure 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 toward the primary fixed sheave 61, and the interval (groove width) between the primary fixed sheave 61 and the primary movable sheave 62 becomes smaller. Accordingly, the winding diameter of the belt 58 around the primary pulley 56 increases, and the interval (groove width) between the secondary fixed sheave 65 and the secondary movable sheave 66 of the secondary pulley 57 increases. As a result, the belt transmission ratio becomes smaller.

When the belt speed ratio is increased, the hydraulic pressure supplied to the hydraulic chamber 64 of the primary pulley 56 is lowered. As a result, the thrust force of the secondary pulley 57 with respect to the belt 58 becomes larger than the thrust force of the primary pulley 56 with respect to the belt 58, the interval 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 and the primary movable sheave 62 becomes larger. As a result, the belt transmission ratio increases.

A bias spring 69 is provided in the hydraulic chamber 68 of the secondary pulley 57. The bias spring 69 has one end in elastic contact with the secondary movable sheave 66 and the other end in elastic contact with the piston 67. The elastic force of the bias spring 69 urges the secondary movable sheave 66 and the piston 67 in a direction away from each other. A biasing force is applied to the secondary movable sheave 66 by the hydraulic pressure in the hydraulic chamber 68 and a bias spring 69, and a corresponding pinching pressure is applied to the belt 58.

Further, an input gear 81 is integrally formed in the input shaft 41 at the center in the axial direction. Correspondingly, a primary input gear 82 that meshes with the input 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 gear 81 and the primary input gear 82 and the oil pump 45 that mesh with each other. . A portion of the forward clutch 83 overlaps the oil pump 45 in the axial radial direction (overlapping when viewed in the axial direction).

Forward clutch 83 includes a clutch drum 84, a clutch hub 85, and a clutch piston 86. The clutch drum 84 has an inner peripheral end fixed to the primary shaft 54, extends from the primary shaft 54 in the radial direction, and an outer peripheral end bent and extends toward the primary input gear 82, that is, toward the front. 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 apart from the inner side in the radial direction of the shaft relative to the outer peripheral end of the clutch drum 84. They are facing each other. Clutch piston 86 is provided between clutch drum 84 and clutch hub 85 so as to be movable in the axial direction. The clutch piston 86 is in fluid-tight contact with the clutch drum 84, and a hydraulic chamber 87 is formed between the clutch drum 84 and the clutch piston 86 to which hydraulic pressure acting on the clutch piston 86 is supplied. . Further, the clutch piston 86 is elastically biased rearward by a 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 radial direction, clutch plates held by the clutch drum 84 and clutch discs held by the clutch hub 85 are arranged alternately in the axial direction. There is. When the clutch piston 86 moves forward 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 disk come into pressure contact, and the forward clutch 83 is engaged. Engagement of forward clutch 83 inhibits rotation of primary input gear 82 with respect to primary shaft 54, and when primary input gear 82 rotates, primary shaft 54 rotates together with primary input gear 82. When the hydraulic pressure is released from the engaged state of the forward clutch 83, the clutch piston 86 moves rearward due to the biasing force of the return spring 88, the pressure contact between the clutch disc and the clutch plate is released, and the forward clutch 83 is released. To be released. By releasing the forward clutch 83, rotation of the primary input gear 82 with respect to the primary shaft 54 is allowed, 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 by the secondary shaft 55 so as to be relatively rotatable. Secondary input gear 91 is arranged between input gear 81 and oil pump 45 in the axial direction. Further, a reverse clutch 92 is provided that utilizes the space between the secondary input gear 91 and the oil pump 45 to allow/prohibit rotation of the secondary input gear 91 with respect to the secondary shaft 55. A portion of the reverse clutch 92 overlaps the oil pump 45 in the radial direction (overlapping 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 clutch drum 93 has an inner circumferential end fixed to the secondary shaft 55, extends from the secondary shaft 55 in the radial direction, and an outer circumferential end bent toward the secondary input gear 91, that is, toward the front. 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 apart from the inner side in the axial radial direction with respect to the outer peripheral end of the clutch drum 93. They are facing each other. Clutch piston 95 is provided between clutch drum 93 and 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 is formed between the clutch drum 93 and the clutch piston 95 to which hydraulic pressure acting on the clutch piston 95 is supplied. . Further, the clutch piston 95 is elastically urged rearward by a 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 radial direction, clutch plates held by the clutch drum 93 and clutch discs held by the clutch hub 94 are arranged alternately in the axial direction. There is. When the clutch piston 95 moves forward 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 disk come into pressure contact, and the reverse clutch 92 is engaged. By engaging the reverse clutch 92, rotation of the secondary input gear 91 with respect to the secondary shaft 55 is prohibited, and when the secondary input gear 91 rotates, the secondary shaft 55 rotates together with the secondary input gear 91. When the hydraulic pressure is released from the engaged state of the reverse clutch 92, the clutch piston 95 moves rearward due to the biasing 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, 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 between them on the rear side. In other words, the input shaft 41 and the output shaft 43 are arranged front and rear with an interval in the axial direction, respectively, so as to have a common axis extending vertically along the longitudinal direction of the vehicle. An output transmission gear 101 is integrally formed with the output shaft 43. Correspondingly, a secondary output gear 102 that meshes with the output transmission gear 101 is supported on the secondary shaft 55 so as not to be relatively 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. Reverse idler shaft 103 extends in the axial direction, straddles first transmission case 11 and second transmission case 12, and is rotatably supported by first transmission case 11 and second transmission case 12. The first reverse gear 104 is formed integrally with the reverse idler shaft 103 and meshes with the input 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 made of, for example, an aluminum alloy, and is a casting cast by a die-casting method. The adapter 111 extends between the output shaft 43 and the primary shaft 54 in the axial radial direction. The upper end of the adapter 111 protrudes rearward, and a substantially cylindrical recess 112 is formed in the protruding portion toward the front. The front end of the output shaft 43 is inserted into the recess 112. A radial bearing 113 is interposed between the circumferential surface of the output shaft 43 and the inner circumferential surface of the recess 112. A front end portion of the output shaft 43 is rotatably supported by the adapter 111 via a radial bearing 113. Further, the output shaft 43 has an annular stepped surface extending in the radial direction of the shaft between the portion where the output transmission 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. Thereby, the front end portion of the output shaft 43 is rotatably supported by the adapter 111 via the radial bearing 113 and the thrust bearing 114.

Further, the adapter 111 has a substantially cylindrical recess 115 formed on the rear side. The rear end portion of the primary shaft 54 is inserted into the recess 115. A ball bearing 116 is interposed between the circumferential surface of the primary shaft 54 and the inner circumferential surface of the recess 115. A rear end portion of the primary shaft 54 is rotatably supported by the adapter 111 via a ball bearing 116.

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

<Power transmission path>
FIG. 2 is a skeleton diagram schematically showing the configuration of the CVT 5. As shown in FIG.

When the vehicle moves forward, the forward clutch 83 is engaged and the reverse clutch 92 is released. Power input from the engine 2 to the input shaft 41 via the torque converter 4 is transmitted from the input gear 81 to the primary shaft 54 via the primary input gear 82 by 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 gear 81 to the secondary input gear 91 and the secondary input gear 91 rotates, the release of the reverse clutch 92 causes the secondary input gear 91 to move from the secondary shaft 55 ( The secondary shaft 55) rotates idly, and no power is transmitted to the secondary shaft 55.

The power transmitted to the primary shaft 54 is transmitted to the secondary shaft 55 after being changed in speed at a belt speed ratio according to the pulley ratio of the primary pulley 56 and the secondary pulley 57. The power transmitted to the secondary shaft 55 is transmitted from the secondary output gear 102 to the output shaft 43 via the output transmission gear 101.

When the vehicle is traveling backwards, the forward clutch 83 is released and the reverse clutch 92 is engaged. Power input from the engine 2 to the input shaft 41 via the torque converter 4 is transmitted from the input gear 81 to the secondary shaft 55 via the reverse transmission mechanism 44 and the secondary input gear 91 by engagement of the reverse clutch 92. . At this time, the secondary shaft 55 rotates in the opposite direction to when the vehicle moves forward. On the other hand, even if the power input to the input shaft 41 is transmitted from the input gear 81 to the primary input gear 82 and the primary input gear 82 rotates, the release of the forward clutch 83 causes the primary input gear 82 to rotate to the primary shaft 54 ( The primary shaft 54) rotates idly, and no power is 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 transmission gear 101.

The power transmitted to the output shaft 43 is output from the output shaft 43 to the propeller shaft 118, and transmitted from the propeller shaft 118 to the left and right rear wheels via a rear differential gear (rear differential) and a drive shaft.

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

Further, a strainer 122 is provided at the bottom of the second transmission case 12. The strainer 122 includes a filtration part 123 arranged side by side with the valve body 121 and a pipe part 124 extending from the filtration part 123. The pipe portion 124 extends forward from the lower portion of the filter portion 123 and extends below the valve body 121 . The tube section 124 is formed into a hollow tube shape, and the inside thereof communicates with the inside of the filtration section 123. Further, the lower surface of the tip of the tube portion 124 is open 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 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 oil accumulated in the oil pan 131 is sucked into the pipe portion 124 from the suction port 125. The oil sucked into the pipe part 124 flows inside the pipe part 124 toward the filter part 123 and passes through a filter material provided in the filter part 123. As the oil passes through the filter medium, foreign substances contained in the oil are captured by the filter medium and 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 as hydraulic oil or lubricating oil from the valve body 121 to various parts such as the continuously variable transmission mechanism 42 that require oil supply.

<Bush lubrication>
FIG. 3 is a cross-sectional view showing the vicinity of the output shaft 43 on a larger scale than in FIG.

A substantially cylindrical outer cylindrical portion 141 is formed at the rear end portion of the third transmission case 13 . The outer cylindrical portion 141 has a center line extending on the axis of the output shaft 43 and is open on both sides in the axial direction. The output shaft 43 is inserted into the outer cylindrical part 141 from the front side and passes through the outer cylindrical part 141. An outer ring of a ball bearing 142 is press-fitted into an opening at the front end of the outer cylindrical portion 141 , and the output shaft 43 is connected to the outer cylindrical portion 141 through the ball bearing 142 . is rotatably supported.

Inside the outer cylindrical part 141, an inner cylindrical part 143 is formed integrally with the outer cylindrical part 141. The inner cylindrical part 143 has its center line extending on the axis of the output shaft 43, surrounds the output shaft 43 with a space between it and the outer peripheral surface of the output shaft 43, and is open on both sides in the axial direction. .

The front end of the propeller shaft 118 has a cylindrical connecting portion 144 . The connecting portion 144 is inserted into a space 145 between the inner circumferential surface of the inner cylindrical portion 143 and the outer circumferential surface of the output shaft 43 from the rear side. A spline is formed on the outer peripheral surface of the output shaft 43. Correspondingly, a spline is formed on the inner circumferential surface of the connecting portion 144, and the output shaft 43 and the connecting portion 144 are coupled to each other so that they cannot rotate relative to each other by engaging these splines. There is.

Further, a cylindrical bush 146 made of metal is fixed to the inner peripheral surface of the inner cylindrical portion 143. A connecting portion 144 of the propeller shaft 118 is rotatably supported by the inner cylindrical portion 143 via a bush 146.

A front end portion of the inner cylindrical portion 143 is bent toward the axis of the output shaft 43 and enters between the output shaft 43 and the propeller shaft 118 . As a result, a weir 147 formed from the front end of the inner cylindrical portion 143 is formed between the ball bearing 142 and the space 145 in which the bush 146 is arranged.

The output shaft 43 is formed with an axial oil passage 151 extending along its axis. The axial oil passage 151 opens at the front end of the output shaft 43 and communicates with an adapter oil passage 152 formed in the adapter 111. An oil passage (not shown) extending from the valve body 121 is connected to the adapter oil passage 152, and oil delivered from the valve body 121 is supplied through the oil passage. An oil passage connecting the valve body 121 and the adapter oil passage 152 is formed in the unit case 3.

Furthermore, a communication oil passage 153 is formed in the output shaft 43. The communication oil passage 153 has one end connected to the axial oil passage 151 and communicates with the axial oil passage 151 . The communication oil passage 153 extends in the radial direction of the output shaft 43, is opened at the outer peripheral surface of the output shaft 43, and communicates with the space 145 in which the bush 146 is disposed.

<Effect>
When oil is supplied to the shaft oil passage 151, the oil flows from the shaft oil passage 151 into the communication oil passage 153, and the oil flows from the communication oil passage 153 into the space between the propeller shaft 118 and the inner cylindrical portion 143. Released at 145. When the output shaft 43 rotates, oil is radially released around the output shaft 43 from the communication oil passage 153 as the output shaft 43 rotates. Therefore, oil can be evenly supplied to the entire circumference of the bush 146 in the circumferential direction. As a result, the bush 146 can be well lubricated, and the lubrication performance of the bush 146 in the transmission unit 1 can be improved.

Further, the transmission unit 1 is mounted on the vehicle so that the input shaft 41 is inclined downward toward the rear. Therefore, even if the vehicle is tilted forward on a downhill slope, the oil released from the communication oil passage 153 can be supplied to the bush 146. Therefore, the bush 146 can be lubricated even better.

The output shaft 43 is rotatably supported by the outer cylindrical part 141 of the third transmission case 13 via a ball bearing 142, and the front end of the inner cylindrical part 143 in the axial direction is bent toward the output shaft 43. A weir 147 is set between the space 145 where the bush 146 is arranged and the ball bearing 142. Thereby, the oil released from the communication oil passage 153 can be stored in the space 145 where the bush 146 is arranged. Therefore, oil can be supplied to the bush 146 better, and the performance of lubricating the bush 146 can be further improved. Furthermore, oil overflowing over the weir 147 is supplied to the ball bearing 142 that supports the output shaft 43. Therefore, the ball bearing 142 can be lubricated with oil. Moreover, the amount of oil supplied to the ball bearing 142 can be adjusted by the height of the weir 147, and the balance between the lubrication of the bush 146 and the lubrication of the ball bearing 142 can be easily adjusted.

Furthermore, since oil is supplied to the shaft center oil passage 151 from an adapter oil passage 152 formed in the adapter 111, an oil passage from the valve body 121 to the adapter oil passage 152 is formed in the unit case 3. It is good. Therefore, compared to a configuration in which the oil passage from the valve body 121 to the space 145 where the bush 146 is arranged is formed in the unit case 3, the length of the oil passage formed in the unit case 3 is shortened, and the oil passage is formed. The thickness of the unit case 3 secured for this purpose can be made thinner. As a result, the amount of raw materials in the unit case 3 can be reduced, and the weight and cost of the unit case 3 can be reduced.

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

For example, in the above-described embodiment, the transmission unit 1 is arranged vertically behind the engine 2, with the input shaft 41 of the CVT 5 extending vertically in the longitudinal direction of the vehicle. However, the present invention is not limited thereto, and can also be applied to a transmission unit that is placed horizontally on the left or 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 system of the continuously variable transmission mechanism 42 is not limited to the belt type, but may be a chain type or a toroidal type.

Furthermore, the transmission mechanism provided in the transmission unit 1 is not limited to the continuously variable transmission mechanism 42, but may be a stepped transmission mechanism.

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

1: Speed change unit (power transmission device)
3: Unit case (case)
43: Output shaft 111: Adapter 118: Propeller shaft 142: Ball bearing (bearing)
143: Inner cylindrical part (cylindrical part)
147: Weir 146: Bush 151: Axial oil passage 153: Communication oil passage

Claims (3)

A power transmission device mounted on a vehicle,
A case forming the outer shell,
an adapter provided within the case and supported by the case;
an output shaft rotatably supported by the adapter;
a propeller shaft coupled to the output shaft and to which power is transmitted from the output shaft;
The case includes an outer cylindrical part whose center line extends on the axis of the output shaft, and an outer cylindrical part that is open on both sides in the axial direction of the output shaft, and an outer cylindrical part inside the outer cylindrical part. an inner cylindrical part that is formed with a space, extends on the axis of the output shaft, and is open on both sides in the axial direction;
The output shaft is inserted into the outer cylindrical part from one side in the axial direction , passes through the outer cylindrical part, and passes through a bearing press-fitted into the one end of the outer cylindrical part. rotatably supported by the outer cylindrical part ,
The propeller shaft is inserted into the inner cylindrical part from the other side in the axial direction, and is rotatable into the inner cylindrical part via a bushing interposed between the propeller shaft and the inner circumferential surface of the inner cylindrical part. It is supported by
The output shaft includes:
an axial oil passage extending on the axial center of the output shaft and to which oil is supplied;
A communicating oil passage is formed that communicates with the axial oil passage, is open at the circumferential surface of the output shaft, and communicates with the space between the output shaft and the inner cylindrical part. Power transmission device. The communication oil passage is provided on the one side in the axial direction with respect to the bush,
The output shaft is mounted on the vehicle such that the one side in the axial direction is the front side of the vehicle, the other side in the axial direction is the rear side of the vehicle, and the axis of the output shaft is inclined backwardly. , The power transmission device according to claim 1. The inner cylindrical portion has an end portion on the one side in the axial direction bent toward the output shaft to set a dam between the space and the bearing. Power transmission device.

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