JP7427330B2 - oil supply structure - Google Patents

Description

The present invention relates to a structure for supplying oil for lubrication to a clutch disc of a wet clutch.

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.

As a transmission for a vehicle in which an engine is mounted vertically, a vertically mounted CVT (Continuously Variable Transmission) has already been provided. A CVT for vertical installation is arranged so that the input shaft is oriented vertically with respect to the longitudinal direction of the vehicle body. The output shaft that outputs power to the propeller shaft is spaced rearward from the input shaft, and an endless belt is wound around the primary and secondary pulleys between the input shaft and the output shaft. A continuously variable transmission mechanism is provided. Engine power is input to the input shaft via a torque converter. The power input to the input shaft is changed in speed by the continuously variable transmission mechanism and transmitted to the output shaft. The power output from the output shaft to the propeller shaft is distributed to the left and right drive shafts by a differential gear, and then transmitted to the left and right rear wheels.

Japanese Patent Application Publication No. 1-208232

A CVT with such a configuration can achieve two-wheel drive using the left and right rear wheels by connecting a transfer to the output shaft and installing a hydraulic clutch (wet clutch) that switches between transmitting and cutting off power from the output shaft to the transfer. It can be changed to a 4WD (four-wheel drive) specification that can be switched to four-wheel drive with the left and right front wheels and rear wheels.

In 4WD models equipped with wet clutches, it is necessary to supply oil to the clutch discs to lubricate them in order to prevent the clutch discs from becoming worn, worn out, or burnt. For this purpose, for example, oil is released from an axial oil passage provided on the output shaft between the clutch piston and a balancer (canceller) that faces the clutch piston with a return spring in between, and the released oil is transferred to the balancer. A configuration in which the oil is supplied to the clutch disk through a notch formed in the clutch hub and an oil supply hole formed in the clutch hub is considered.

However, the oil discharged from the notch in the balancer toward the clutch hub has difficulty passing through the oil supply hole in the clutch hub, which prevents oil from being properly supplied to the clutch disc, which may result in insufficient lubrication of the clutch disc.

An object of the present invention is to provide an oil supply structure that can satisfactorily supply oil to a clutch disc of a wet clutch.

In order to achieve the above object, the oil supply structure according to the present invention includes a cylindrical plate holding part that is provided to rotate together with the first rotating body around the rotational axis and whose center line is the rotational axis. a clutch drum having a clutch drum, and a disk holding part that is provided to rotate together with the second rotating body around the rotational axis, has a cylindrical shape centered on the rotational axis, and faces the plate holding part in the rotational radial direction. A clutch hub, a clutch plate having an annular plate shape with the rotation axis as the center line, held by the plate holder and disposed between the plate holder and the disc holder, and a clutch plate with the rotation axis as the center line. a clutch disc that has an annular plate shape, is held by a disc holder, and is disposed between the plate holder and the disc holder on one side of the clutch plate in the axial direction in which the rotational axis extends; a clutch piston that is provided movably in the axial direction and applies pressure to the clutch plate to press the clutch plate against the clutch disk; a clutch piston that surrounds the first rotating body and is fixedly provided with respect to the first rotating body; a balancer disposed between the clutch hub and the clutch piston; and an urging member interposed between the clutch piston and the balancer and urging the clutch piston and the balancer to move away from each other in the axial direction. The first rotating body and the second rotating body are coupled to each other so as to rotate together by pressure contact between the clutch plate and the clutch disc, and the first rotating body and the second rotating body are coupled to each other by releasing the pressure contact. The clutch is configured to supply oil for lubrication to the clutch disk in a clutch that switches between a released state and a released state in which the clutch disk is relatively rotatably separated. An oil hole is formed through the space so that the oil flowing into the space between the clutch plate and the clutch piston flows out towards the clutch disc. A blocking portion is provided to prevent the fluid from flowing.

According to this configuration, the cylindrical plate holding portion of the clutch drum and the cylindrical disk holding portion of the clutch hub face each other in the rotational radial direction, and the clutch plate and the clutch disk are arranged between them. has been done. A clutch piston is provided to be movable in the axial direction, and when the clutch piston applies pressure to the clutch plate, the clutch plate and the clutch disk come into pressure contact, and the clutch is brought into an engaged state. Further, a balancer is arranged between the clutch hub and the clutch piston. A biasing member is interposed between the clutch piston and the balancer to bias the clutch piston in a direction to separate the clutch piston from the balancer. Due to the bias, the clutch piston moves in a direction away from the balancer, and when the pressure contact between the clutch plate and the clutch disk is released, the clutch is released.

In a clutch having such a structure, in order to supply oil for lubrication to the clutch disc, an oil hole is formed through the clutch hub at a position inside the disc holding portion in the rotational radial direction. The oil hole is provided to allow oil flowing into the space between the clutch hub and balancer to flow out toward the clutch disc. When oil flows out from the oil hole, the oil is supplied to the clutch disc. The clutch disc is lubricated with oil.

However, as a result of research conducted by the inventor of the present application, it has been found that when the oil that has flowed into the space between the clutch hub and the balancer flows toward the contact area between the clutch plate and the clutch piston, the amount of oil that flows out from the oil hole is small. It was found that there was a risk that the clutch disc would not be sufficiently supplied with oil.

Therefore, a blocking portion is provided in the space between the clutch hub and the balancer to prevent the oil that has flowed into the space from flowing toward the contact portion between the clutch plate and the clutch piston. Thereby, the amount of oil flowing out from the oil hole can be ensured, and oil can be well supplied to the clutch disc. As a result, it is possible to prevent the clutch disk from becoming insufficiently lubricated, and it is possible to suppress the occurrence of wear, wear, burnout, etc. of the clutch disk.

An inflow window through which oil flowing into the space flows toward the space may be formed at the inner peripheral end of the balancer. In this case, the blocking portion extends from a position outside the oil hole in the clutch hub in the rotational radial direction toward the inlet window, and forms an oil pool between the blocking portion and a portion of the clutch hub that is inside the oil hole in the rotational radial direction. It may be a return part that sets the area and guides the oil flowing toward the area so as to return to the inflow window side.

According to this configuration, oil accumulates in a region that becomes an oil reservoir, and the accumulated oil flows out from the oil hole. Therefore, it is possible to secure a larger amount of oil flowing out from the oil hole, and it is possible to supply oil to the clutch disc even better.

The blocking portion may be an annular sealing member that seals between the balancer and a portion of the clutch hub that is outside the oil hole in the rotational radial direction.

With this configuration, oil does not flow between the balancer and the part outside the oil hole in the clutch hub in the rotational radial direction, so it is possible to secure a large amount of oil flowing out from the oil hole, and more oil can be applied to the clutch disc. It can be supplied even better.

Also, if oil flows between the clutch plate and clutch piston through the gap between the clutch hub and balancer, the clutch plate will be pressed against the clutch disc by centrifugal hydraulic pressure when the clutch rotates in the released state (disengaged state). Therefore, there is a concern that the drag loss of the clutch will increase. When a clutch is installed in a vehicle, an increase in clutch drag loss leads to deterioration in fuel efficiency.

Since the seal member effectively prevents oil from flowing between the clutch plate and the clutch piston through the gap between the clutch hub and balancer, it is possible to suppress the occurrence of clutch drag loss when the clutch rotates in the open state. , When the clutch is mounted on a vehicle, deterioration of fuel efficiency of the vehicle can be suppressed.

According to the present invention, oil can be well supplied to the clutch disc of a wet clutch.

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 cross-sectional view showing a rear end portion of the transmission unit, that is, a portion including a transfer, on a larger scale than in FIG. 1; FIG. 2 is a skeleton diagram schematically showing the configuration of a CVT and a transfer. FIG. 7 is a cross-sectional view for explaining another embodiment.

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 is a part-time 4WD (four-wheel-drive) vehicle based on FR (front engine, rear drive).

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, a CVT (Continuously Variable Transmission) 5, and a transfer 6 within a unit case 3 forming an outer shell.

<Unit case>
Unit case 3 includes a transmission case that accommodates torque converter 4 and CVT 5, and a transfer case that accommodates transfer 6. The transmission case is composed of three parts: a first transmission case 11, a second transmission case 12, and a third transmission case 13. The transfer case is composed of two parts: a first transfer case 14 and a second transfer case 15. The first transmission case 11, the second transmission case 12, the third transmission case 13, the first transfer case 14, and the second transfer case 15 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 the bolts 16, and the second transmission case 12 and the third transmission case 13 are fastened with the bolts 17, so that the first transmission case 11 and the second transmission Case 12 and third transmission case 13 are integrated.

The first transfer case 14 and the second transfer case 15 are arranged in this order from the front side. The first transfer case 14 and the second transfer case 15 are integrated by being fastened with bolts 18. The first transfer case 14 is fastened to the third transmission case 13 with bolts 19, so that the transmission case and the transfer case 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 arranged vertically behind the engine 2 so that the input shaft 41 of the CVT 5 extends vertically in the longitudinal direction of the vehicle.

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

In the following description, the direction in which the axis of the input shaft 41 extends will be referred to as the "axial direction." Further, a direction perpendicular to the axial direction, that is, a radial direction of the input shaft 41 is referred to as a "shaft 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 substantially cylindrical recess 51 is formed at the front end of the pump case 46 on the rear side. The rear end of the input shaft 41 is inserted into the recess 51 and is rotatable 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. 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. This reduces mechanical loss when the input shaft 41 rotates.

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 extends parallel to the input shaft 41 between the first transmission case 11 and the second transmission case 12 at a position spaced apart to the lower right from the input shaft 41 when viewed from the rear side of the vehicle. It is rotatably provided around its axis.

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

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 sheave 65 which is disposed opposite to the secondary fixed sheave 65 with a belt 58 interposed therebetween, and which 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 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 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 shaft gear 81 is integrally formed in the center of the input shaft 41 in the axial direction. Correspondingly, a primary input gear 82 that meshes with an input shaft gear 81 is supported by the primary shaft 54 so as to be relatively rotatable. A forward clutch 83 is provided that utilizes the space between the input shaft gear 81 and the primary input gear 82 and the oil pump 45 that mesh with each other to allow/prohibit rotation of the primary input gear 82 with respect to the primary shaft 54. There is. 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 shaft 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 disengaging 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 shaft 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 peripheral end fixed to the secondary shaft 55, extends from the secondary shaft 55 in the shaft radial direction, and an outer peripheral end bent and extends toward the secondary input gear 91 side, that is, toward 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 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 disposed 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 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 shaft gear 101 is integrally formed with the output shaft 43 . Correspondingly, a secondary output gear 102 that meshes with the output shaft 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. The reverse idler shaft 103 extends in the axial direction, spans 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.

<Transfer>
FIG. 2 is a cross-sectional view showing a rear end portion of the transmission unit 1, that is, a portion including the transfer 6, in a larger scale than in FIG. Hereinafter, the configuration of the transfer 6 will be described with appropriate reference to FIG. 2 in addition to FIG. 1.

The transfer 6 is a mechanism that transmits the power (rotation) of the output shaft 43 to the front wheels of the vehicle. The transfer 6 includes a transmission shaft 111, a first sprocket 112, a second sprocket 113, a chain 114, and a 4WD clutch 115.

The transmission shaft 111 extends parallel to the output shaft 43 and straddles the first transfer case 14 and the second transfer case 15 at a position spaced apart from the output shaft 43 in the shaft radial direction. There is. An inner ring of a ball bearing 116 is fixed to the rear end of the transmission shaft 111 by press fitting. Further, an inner ring of a ball bearing 117 is fixed to the transmission shaft 111 by press fitting at a position spaced from the ball bearing 116 on the front side. The outer ring of the ball bearing 116 is fixedly held in the second transfer case 15, and the outer ring of the ball bearing 117 is fixedly held in the first transfer case 14, so that the transmission shaft 111 is connected to the first transfer case 15. 14 and a second transfer case 15 in a rotatable manner.

The first sprocket 112 is rotatably supported by the first transfer case 14 and the second transfer case 15, and is fitted onto the output shaft 43 so as to be relatively rotatable. Specifically, the first sprocket 112 includes a substantially annular plate-shaped sprocket portion 121 that surrounds the output shaft 43, a front side extension portion 122 that extends forward from the inner peripheral portion of the sprocket portion 121, and a sprocket portion 121 that has a substantially annular plate shape that surrounds the output shaft 43. It integrally has a rear side extension part 123 extending rearward from the inner peripheral part of the part 121. A plurality of teeth are formed on the outer periphery of the sprocket portion 121 at equal intervals in the circumferential direction. An inner ring of a ball bearing 124 is press-fitted into the front extending portion 122 . Further, an inner ring of a ball bearing 125 is fitted onto the rear side extension portion 123 by press fitting. The outer ring of the ball bearing 124 is fixedly held by the first transfer case 14, and the outer ring of the ball bearing 125 is fixedly held by the second transfer case 15. As a result, the first sprocket 112 is rotatably supported by the first transfer case 14 and the second transfer case 15 via the ball bearings 124 and 125 while being fitted onto the output shaft 43 so as to be relatively rotatable. ing.

The second sprocket 113 is formed integrally with the transmission shaft 111 between the ball bearings 116 and 117, and has a substantially annular plate shape extending from the transmission shaft 111 in the shaft radial direction. A plurality of teeth are formed on the outer periphery of the second sprocket 113 at equal intervals in the circumferential direction.

The chain 114 is formed in an endless shape and is wound around the sprocket portion 121 of the first sprocket 112 and the second sprocket 113.

The 4WD clutch 115 is provided in front of the first sprocket 112. The 4WD clutch 115 includes a clutch drum 131, a clutch hub 132, a clutch piston 133, and a balancer 134.

A substantially cylindrical cylindrical member 135 is externally fitted and fixed to the output shaft 43 between the output shaft gear 101 and the first sprocket 112 . A space is provided between the cylindrical member 135 and the first sprocket 112. At a central portion of the cylindrical member 135 in the axial direction and at a position facing the rear end portion of the secondary shaft 55 in the radial direction of the shaft, a flange-shaped connecting portion 136 that extends in the radial direction of the shaft is connected to the cylindrical member 135. It is formed in one piece.

The clutch drum 131 is rotationally symmetrical about the axis of the output shaft 43, and has a substantially annular shape surrounding the entire circumference of the connecting portion 136 of the cylindrical member 135 when viewed in the axial direction. An inner peripheral end of the clutch drum 131 is fixed to a connecting portion 136. The clutch drum 131 extends from the inner peripheral end in a direction intersecting the axial direction, crosses the secondary shaft 55 to the rear side, and is bent rearward at a position facing the secondary shaft 55 from the rear side in the axial direction. It extends axially from that position. In other words, the clutch drum 131 includes an enlarged diameter portion 137 whose diameter increases rearward from the connection portion 136, and a substantially cylindrical cylinder that extends rearward in the axial direction from the rear end (outer peripheral end) of the enlarged diameter portion 137. The front end of the enlarged diameter part 137 faces the rear end of the secondary shaft 55 in the radial direction, and the cylindrical part 138 faces the rear end of the secondary shaft 55. They face each other from the rear in the axial direction. Further, a portion of the clutch drum 131 extending in the axial direction, that is, a cylindrical portion 138 faces the front extending portion 122 of the first sprocket 112 in the radial direction of the shaft. A plurality of clutch plates 139 are held on the inner circumferential surface of the cylindrical portion 138 so as to be spaced apart from each other in the axial direction.

A support member 141 is provided between the first sprocket 112 and the cylindrical member 135. The support member 141 includes a substantially cylindrical outer fitting portion 142 surrounding the output shaft 43 and a flange-shaped (annular plate-shaped) flange portion 143 extending in the shaft radial direction from the front end of the outer fitting portion 142. It has an integrated structure. The outer fitting part 142 enters between the front side extension part 122 of the first sprocket 112 and the output shaft 43, and the front side extension part 122 of the first sprocket 112 fits into the outer fitting part 142 and the cylindrical shape of the clutch drum 131. It faces the portion 138 in the axial radial direction. The outer circumferential surface of the outer fitting part 142 is coupled to the inner circumferential surface of the front side extension part 122 of the first sprocket 112 by spline fitting so that relative rotation is not possible. The inner circumferential surface of the outer fitting portion 142 is not in close contact with the circumferential surface of the output shaft 43, and a minute gap is created between the outer circumferential surface of the output shaft 43 and the inner circumferential surface of the outer fitting portion 142. There is. As a result, the support member 141 cannot rotate relative to the first sprocket 112, but can rotate relative to the output shaft 43. A thrust bearing 144 is interposed between the cylindrical member 135 and the support member 141 in order to reduce mechanical loss during their relative rotation.

The clutch hub 132 is rotationally symmetrical about the axis of the output shaft 43, and has a substantially annular shape that surrounds the entire circumference of the brim 143 of the support member 141 when viewed in the axial direction. An inner peripheral end of the clutch hub 132 is fixed to a flange-shaped portion 143. The clutch hub 132 extends outward in the radial direction of the shaft from the brim portion 143, and is bent rearward at a position spaced inward in the radial direction of the shaft relative to the cylindrical portion 138 of the clutch drum 131. It extends in the axial direction from. In other words, the clutch hub 132 includes a substantially annular plate-shaped portion 151 that extends from the flange portion 143 to the periphery, and a substantially circular plate-shaped portion 151 that extends rearward in the axial direction from the outer peripheral end of the circular plate portion 151. The cylindrical portion 152 is arranged inside the cylindrical portion 138 of the clutch drum 131 in the radial direction of the shaft, and the cylindrical portion 152 has a cylindrical portion 152. It has a heavy cylindrical shape. A plurality of clutch disks 153 are held on the outer peripheral surface of the cylindrical portion 152 in an axially spaced manner. Clutch plates 139 and clutch discs 153 are arranged alternately in the axial direction.

Clutch piston 133 is provided between clutch drum 131 and clutch hub 132 so as to be movable in the axial direction. The clutch piston 133 extends from the cylindrical member 135 toward the clutch plate 139 while repeatedly bending. A seal member 154 is provided in the middle of the clutch piston 133, and the seal member 154 contacts the clutch drum 131 in a liquid-tight manner regardless of the position of the clutch piston 133. As a result, a hydraulic chamber 155 is formed between the clutch drum 131 and the clutch piston 133 to which hydraulic pressure acting on the clutch piston 133 is supplied.

Balancer 134 is provided between clutch hub 132 and clutch piston 133. The balancer 134 is formed into a substantially annular plate shape. The inner peripheral end of the balancer 134 is fixed to a cylindrical member 135. A seal member 156 is provided at the outer peripheral end of the balancer 134, and this seal member 156 abuts against the clutch piston 133 regardless of the position of the clutch piston 133. A return spring 157 is interposed between the clutch piston 133 and the balancer 134. Due to the biasing force (elastic force) of the return spring 157, the clutch piston 133 and the balancer 134 are elastically biased in a direction away from each other.

The clutch piston 133 moves toward the clutch plate 139 by the hydraulic pressure supplied to the hydraulic chamber 155 and presses the clutch plate 139. This pressing causes the clutch plate 139 and the clutch disc 153 to come into pressure contact, and the 4WD clutch 115 is engaged. By engaging the 4WD clutch 115, relative rotation between the clutch drum 131 and the clutch hub 132 is prevented, the support member 141 rotates together with the output shaft 43 and the cylindrical member 135, and the first Sprocket 112 rotates. The rotation (power) of the first sprocket 112 is transmitted to the second sprocket 113 via the chain 114, causing the second sprocket 113 to rotate in the same direction as the first sprocket 112. Then, the transmission shaft 111 rotates together with the second sprocket 113.

When the hydraulic pressure in the hydraulic chamber 155 is released from the engaged state of the 4WD clutch 115, the clutch piston 133 moves in a direction away from the balancer 134 due to the biasing force of the return spring 157, and the clutch plate 139 is pressed by the clutch piston 133. is released. As a result, the pressure contact between clutch plate 139 and clutch disc 153 is released, and 4WD clutch 115 is released. By releasing the 4WD clutch 115, relative rotation between the clutch drum 131 and the clutch hub 132 is allowed. Therefore, even if the output shaft 43 and the cylindrical member 135 rotate, the rotation is not transmitted to the support member 141 and the first sprocket 112, and therefore, the rotation is not transmitted from the first sprocket 112 to the chain 114 and the second sprocket 113. and is not transmitted to the transmission shaft 111 either.

An adapter 161 and an adapter case 162 are provided between the primary shaft 54, the output shaft 43, and the 4WD clutch 115. The adapter 161 and the adapter case 162 are made of, for example, an aluminum alloy, and are cast by die casting.

The adapter 161 extends between the output shaft 43 and the primary shaft 54 in the shaft radial direction. The upper end of the adapter 161 protrudes rearward, and a substantially cylindrical recess 166 is formed in the protruding portion toward the front. The front end of the output shaft 43 is inserted into the recess 166. A radial bearing 167 is interposed between the circumferential surface of the output shaft 43 and the inner circumferential surface of the recess 166. A front end portion of the output shaft 43 is rotatably supported by the adapter 161 via a radial bearing 167. Furthermore, an annular stepped surface 168 along the shaft radial direction is formed on the output shaft 43 between a portion where the output shaft gear 101 is formed and a portion inserted into the recess 166. A thrust bearing 169 is interposed between the stepped surface 168 and the adapter 161.

On the other hand, a needle bearing 170 is interposed between the output shaft 43 and the first sprocket 112. Specifically, the needle bearing 170 is interposed between the output shaft 43 and the inner circumference of the sprocket portion 121 of the first sprocket 112, and is externally fitted onto the front side extension portion 122 of the first sprocket 112 in the axial direction. The ball bearing 124 is disposed between the ball bearing 124 and the ball bearing 125 that is fitted onto the rear extension portion 123 . As a result, the output shaft 43 is relatively rotatably held by the first sprocket 112 via the needle bearing 170, and is held by the first transfer case 14 and the second transfer case via the first sprocket 112 and ball bearings 124, 125. It is rotatably supported by the case 15.

Further, the adapter 161 has a substantially cylindrical recess 171 formed on the rear side. The rear end of the primary shaft 54 is inserted into the recess 171. A ball bearing 172 is interposed between the circumferential surface of the primary shaft 54 and the inner circumferential surface of the recess 171. A rear end portion of the primary shaft 54 is rotatably supported by an adapter 161 via a ball bearing 172.

A bolt 173 is inserted into the lower end of the adapter 161 from the front side. The adapter 161 is attached to the third transmission case 13 by the bolt 173.

Adapter case 162 is attached to third transmission case 13 with bolts 189.

<Oil supply structure>
A valve body 191 is provided at the bottom of the second transmission case 12. A hydraulic circuit including various valves for controlling the supply of oil to each part of the transmission unit 1 is formed in the valve body 191 . Further, a strainer 192 is provided at the bottom of the second transmission case 12. The strainer 192 includes a main body part 193 arranged side by side with the valve body 191 and a pipe part 194 extending from the main part 193 and having a distal end disposed below the valve body 191. Further, an oil pan 195 is fixed to the second transmission case 12 from below with a plurality of bolts 196. The tip of the pipe portion 194 of the strainer 192 is located in the center of the oil pan 195, and the lower surface of the tip is opened as an oil suction port 197 for sucking oil stored in the oil pan 195. ing.

A suction force is generated by the rotation of the pump gear 48 of the oil pump 45, and the oil stored in the oil pan 195 is sucked into the pipe portion 194 from the oil suction port 197. The oil sucked into the pipe portion 194 flows within the pipe portion 194 toward the main body portion 193 and passes through a filtering material provided within the main body portion 193. 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 medium is supplied to the valve body 191. Oil is then supplied as hydraulic oil or lubricating oil from the valve body 191 to various parts such as the continuously variable transmission mechanism 42 that require oil supply.

<4WD clutch lubrication structure>
An axial oil passage 201 is formed in the output shaft 43 and extends on the axial center thereof. Oil as lubricating oil is supplied to the axial oil passage 201 from the valve body 191. The output shaft 43 is further formed with a plurality of distribution oil passages 202 and 203. One end of each of the distribution oil passages 202 and 203 is connected to the axial oil passage 201, and the distribution oil passages 202 and 203 communicate with the axial oil passage 201. The other ends of the distribution oil passages 202 and 203 are open at the outer peripheral surface of the output shaft 43. A lubricating oil passage 204 communicating with the distribution oil passage 202 is formed in the cylindrical member 135 . As a result, the oil flowing through the axial oil passage 201 flows into the space 205 sandwiched between the clutch piston 133 and the balancer 134 of the 4WD clutch 115 via the distribution oil passage 202 and the lubricating oil passage 204. Further, the oil flowing through the shaft center oil passage 201 is released around the output shaft 43 via the distribution oil passage 203.

A plurality of cutout windows 206 are formed at the inner circumferential end of the balancer 134 by cutting out each from the inner circumferential end. A space 205 sandwiched between the clutch piston 133 and the balancer 134 communicates with a space 207 between the clutch hub 132 and the balancer 134 via the cutout window 206.

Specifically, the annular plate-like portion 151 of the clutch hub 132 extends in the radial direction of the shaft from the flange-like portion 143 of the support member 141, extends obliquely so as to bend forward and expand in diameter, and further extends in the radial direction of the shaft. It extends outward in a bent direction. A plurality of oil holes 209 are formed through the diameter-expanding inclined portion 208 that is inclined so as to increase its diameter. Further, the annular plate-shaped portion 151 is provided with a direction toward the notch window 206 from a position outside the oil hole 209 in the axial radial direction, that is, an angle formed by the diameter-expanding inclined portion 208 and a portion extending outward in the axial radial direction. A return portion 211 is formed that extends inward. By forming this return portion 211, an oil reservoir 212 in which oil accumulates due to rotational centrifugal force between the return portion 211 and a portion of the annular plate-shaped portion 151 that extends inward in the axial radial direction than the return portion 211 is formed. An area has been set.

Further, a guide portion 213 is provided in the space 207 between the clutch hub 132 and the balancer 134. The guide portion 213 is fixed to the balancer 134 and has a substantially cylindrical shape extending from the balancer 134 to a position beyond the tip of the return portion 211 in the axial radial direction to the rear side.

With this configuration, oil flowing into the space 205 between the clutch piston 133 and the balancer 134 passes through the cutout window 206 and flows into the space 207 between the clutch hub 132 and the balancer 134. The oil that has flowed into the space 207 is guided by the guide portion 213 and flows toward the oil reservoir 212, and the return portion 211 connects the portion of the clutch hub 132 that extends outward in the shaft radial direction from the enlarged diameter inclined portion 208 to the balancer. 134 (the contact portion between clutch plate 139 and clutch piston 133). Therefore, when the output shaft 43 rotates, oil accumulates in the oil reservoir 212 due to the centrifugal force of the rotation. The oil in the oil reservoir 212 passes through the oil holes 209 and is discharged from the oil holes 209 toward the clutch plates 139 and clutch discs 153 that are arranged alternately.

<Power transmission path>
FIG. 3 is a skeleton diagram schematically showing the configuration of the CVT 5 and the transfer 6. 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 shaft 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 shaft 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 rotate to 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 shaft 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 shaft gear 81 to the secondary shaft 55 via the reverse transmission mechanism 44 and the secondary input gear 91 by engaging the reverse clutch 92. Ru. 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 shaft 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 be transferred to the primary shaft 54. (the primary shaft 54), 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 shaft gear 101.

A vehicle equipped with the transmission unit 1 can be switched between a two-wheel drive state using left and right rear wheels and a four-wheel drive state using left and right front wheels and rear wheels.

When the 4WD clutch 115 is released, the power (rotation) of the output shaft 43 is not transmitted to the first sprocket 112 and is not transmitted to the transmission shaft 111, as described above. On the other hand, the power of the output shaft 43 is transmitted to the propeller shaft, and from the propeller shaft to the left and right rear wheels via the rear differential gear and the drive shaft. As a result, the left and right rear wheels become driving wheels, and the vehicle runs in a two-wheel drive state.

On the other hand, when the 4WD clutch 115 is engaged, as described above, the power of the output shaft 43 is transmitted to the first sprocket 112, and the first sprocket 112 rotates. The rotation (power) of the first sprocket 112 is transmitted to the second sprocket 113 via the chain 114. As a result, the second sprocket 113 rotates in the same direction as the first sprocket 112, and the transmission shaft 111 rotates together with the second sprocket 113. The rotation of the transmission shaft 111 is transmitted to the left and right front wheels via a front differential gear and a drive shaft. On the other hand, the power of the output shaft 43 is transmitted to the propeller shaft, and from the propeller shaft to the left and right rear wheels via the rear differential gear and the drive shaft. As a result, all the left and right front wheels and rear wheels become drive wheels, and the vehicle runs in a four-wheel drive state.

<Effect>
As described above, the oil hole 209 is formed to penetrate through the clutch hub 132 of the 4WD clutch 115. In addition, in the space 205 between the clutch hub 132 and the balancer 134, a blocking portion is provided to prevent oil flowing into the space 205 from flowing toward the contact portion between the clutch plate 139 and the clutch piston 133. A certain barb 211 is provided. Thereby, the amount of oil flowing out from the oil hole 209 can be secured, and the oil can be supplied to the clutch disc 153 in a good manner. As a result, it is possible to prevent the clutch disk 153 from becoming insufficiently lubricated, and it is possible to suppress the occurrence of wear, wear, burnout, etc. of the clutch disk 153.

<Other embodiments>
FIG. 4 is a sectional view for explaining another embodiment.

In FIG. 4, parts corresponding to the parts shown in FIG. 2 are given the same reference numerals as those parts. Furthermore, in the following, explanations of parts with the same reference numerals will be omitted.

In the configuration shown in FIG. 2, the return portion 211 is provided as a blocking portion, but instead of this configuration, the configuration shown in FIG. 4 may be adopted in the transmission unit 1.

In the configuration shown in FIG. 4, the support member 141 includes a substantially cylindrical outer fitting part 142 surrounding the output shaft 43, and a flange-like (annular plate-shaped) extending in the shaft radial direction from the front end of the outer fitting part 142. ) and a substantially cylindrical cylindrical portion 221 extending forward from the outer peripheral end of the collar portion 143. The clutch hub 132 has an inner circumferential end fixed to the tip (front end) of the cylindrical portion 221 of the support member 141, and extends radially outward from the cylindrical portion 221.

In addition, since the clutch hub 132 and the support member 141 are integrated by fixing the clutch hub 132 to the support member 141, it can be said that the support member 141 is a part of the clutch hub of the present invention.

A plurality of oil holes 209 are formed in the cylindrical portion 221 of the support member 141.

Further, the inner circumferential end portion 222 of the balancer 134 is formed in a substantially cylindrical shape surrounding the periphery of the cylindrical member 135, and a plurality of cutout windows 206 are formed on the inner circumferential surface of the inner circumferential end portion 222. There is. A rear end portion of the inner circumferential end portion 222 faces the front end portion of the cylindrical portion 221 of the support member 141 from the inside in the radial direction of the shaft with almost no gap. An annular sealing member 223 is provided on the outer peripheral surface of the inner peripheral end 222 as a blocking part, and this sealing member 223 allows the sealing member 223 to close between the inner peripheral end 222 of the balancer 134 and the cylindrical part 221 of the support member 141. is sealed.

<Effect>
In the configuration shown in FIG. 4, oil does not flow between the portion of the clutch hub 132 outside the oil hole 209 in the shaft radial direction and the balancer 134, so a large amount of oil flowing out from the oil hole 209 can be ensured. This makes it possible to supply oil to the clutch disc 153 even better.

Further, when oil flows between the clutch plate 139 and the clutch piston 133 through the gap between the clutch hub 132 and the balancer 134, when the 4WD clutch 115 rotates in the released state (disengaged state), the centrifugal hydraulic pressure There is a concern that the plate 139 will be pressed against the clutch disc 153 and the drag loss of the 4WD clutch 115 will increase.

Since the sealing member 223 effectively prevents oil from flowing between the clutch plate 139 and the clutch piston 133 through the gap between the clutch hub 132 and the balancer 134, the 4WD clutch 115 is prevented from flowing between the clutch plate 139 and the clutch piston 133. 115 drag loss can be suppressed. As a result, it is possible to prevent the fuel efficiency of the vehicle equipped with the transmission unit 1 from deteriorating due to drag loss of the 4WD clutch 115.

<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 embodiment described above, the transmission unit 1 installed in an FR-based 4WD vehicle was taken up as an example of the power transmission device according to the present invention, but the present invention It can also be applied to a power transmission device mounted on a part-time 4WD vehicle. Further, the present invention may be applied to a power transmission device mounted on a part-time 4WD vehicle based on RR (rear engine/rear drive).

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

115: 4WD clutch (clutch)
131: Clutch drum 132: Clutch hub 133: Clutch piston 134: Balancer 135: Cylindrical member (first rotating body)
139: Clutch plate 153: Clutch disc 206: Cutout window (inflow window)
207: Space 209: Oil hole 211: Return part (blocking part)
212: Oil reservoir 223: Seal member (blocking part)

Claims (1)

a clutch drum that is provided to rotate together with a first rotating body about a rotational axis, and has a cylindrical plate holding part whose center line is the rotational axis;
a clutch hub that is provided to rotate together with the second rotary body around the rotational axis, has a cylindrical disc-holding part centered on the rotational axis, and facing the plate holding part in the rotational radial direction; and,
a clutch plate having an annular plate shape with the rotational axis as the center line, held by the plate holding part, and disposed between the plate holding part and the disk holding part;
an annular plate shape having the rotational axis as a center line, an axis that is held by the disk holding part and that the rotational axis extends with respect to the clutch plate between the plate holding part and the disk holding part; a clutch disc disposed on one side of the direction;
a clutch piston that is movable in the axial direction and applies pressure to the clutch plate to press the clutch plate against the clutch disk;
a balancer surrounding the first rotating body, fixedly provided to the first rotating body, and disposed between the clutch hub and the clutch piston in the axial direction;
an urging member that is interposed between the clutch piston and the balancer and urges the clutch piston and the balancer to move apart from each other in the axial direction;
An engaged state in which the first rotating body and the second rotating body are coupled so as to rotate together by pressure contact between the clutch plate and the clutch disk, and an engaged state in which the first rotating body and the second rotating body are coupled so as to rotate together, and a state in which the first rotating body and the second rotating body are coupled by releasing the pressure contact. In a clutch that switches between a released state and a released state in which the two rotating bodies are relatively rotatably separated,
A structure for supplying oil for lubrication to the clutch disc,
An oil hole passes through the clutch hub at a position inside the disc holding portion in the rotational radial direction, through which oil flowing into the space between the clutch hub and the balancer flows out toward the clutch disc. formed,
The space is provided with a blocking portion that prevents oil flowing into the space from flowing toward a contact portion between the clutch plate and the clutch piston;
In the oil supply structure , the blocking portion is an annular sealing member that seals between a portion of the clutch hub that is outside the oil hole in the rotational radial direction and the balancer .

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