JP7542985B2 - Hydraulic supply structure - Google Patents

Description

The present invention relates to a hydraulic supply structure that is applied to a vehicle transmission, etc.

A belt-type continuously variable transmission (CVT) is known as a transmission installed in vehicles such as automobiles.

A belt-type continuously variable transmission has an endless belt wound around a primary pulley and a secondary pulley. When power from the engine is input to the rotating shaft of the primary pulley, the power is transmitted from the primary pulley to the belt, and from the belt to the secondary pulley.

Each of the primary and secondary pulleys has a fixed sheave fixedly supported on the rotating shaft, and a movable sheave supported on the rotating shaft so that it can move in the axial direction and cannot rotate relative to the rotating shaft. The belt is sandwiched between the fixed and movable sheaves of each pulley and wound around each pulley. Hydraulic pressure is supplied to the movable sheave of each pulley, causing each movable sheave to move and changing the groove width of the primary and secondary pulleys, thereby changing the winding diameter of the belt around the primary and secondary pulleys. This allows the speed ratio (pulley ratio) of the continuously variable transmission to change continuously and infinitely.

JP 2013-113304 A

Figure 5 is a cross-sectional view showing a conventional example of a structure for supplying hydraulic pressure to a movable sheave of a pulley.

The end of the rotating shaft 202, which is integrally formed with the fixed sheave 201, is rotatably supported via a bearing 203 on a case 204 that fits around the continuously variable transmission.

The rotating shaft 202 has an axial oil passage 205 formed therein, which extends along its axis (center line). The axial oil passage 205 is open at an end face 206 that faces the case 204.

A substantially cylindrical bearing holder 207 is formed protruding from the inner surface of the case 204, and the bearing 203 is fitted into the bearing holder 207, with the outer ring being fixedly held by the bearing holder 207. A substantially cylindrical insert 208 extending along the center line of the bearing holder 207 is also formed protruding from the inner surface of the case 204. A plug 211 is fitted into the insert 208. A seal ring 212 is provided on the outer periphery of the plug 211. The insert 208 is inserted into the axial oil passage 205 from the end face 206 of the rotating shaft 202, and the seal ring 212 of the plug 211 comes into liquid-tight contact with the circumferential surface of the axial oil passage 205, thereby sealing between the plug 211 and the circumferential surface of the axial oil passage 205.

The case 204 is also formed with a case oil passage 213 that extends in a direction perpendicular to the axial direction of the rotating shaft 202 and penetrates the case 204 in the perpendicular direction. The hollow portion of the insertion portion 208 communicates with the case oil passage 213 as an introduction oil passage 214. Seal bolts 215, 216 are screwed into both ends of the case oil passage 213. O-rings 217, 218 are provided on the outer periphery of the seal bolts 215, 216, respectively, and the O-rings 217, 218 abut liquid-tightly against the peripheral surface of the case oil passage 213, thereby sealing between the peripheral surface of the case oil passage 213 and the bolts 215, 216.

The case 204 further has a connection oil passage 223 formed at a connection portion 222 with another case 221, the connection oil passage 223 extending in a direction perpendicular to the case oil passage 213. The connection oil passage 223 opens at an end face 225 of the connection portion 222 that abuts against a connection surface 224 of the case 221, and communicates with a supply oil passage 226 in the case 221 that opens at the connection surface 224.

The oil pressure supplied to the movable sheave is supplied from the supply oil passage 226 of the case 221 to the connecting oil passage 223 of the case 204, and is supplied from the connecting oil passage 223 to the axial oil passage 205 of the rotating shaft 202 through the case oil passage 213 and the lead-in oil passage 214. The rotating shaft 202 is formed with a distribution oil passage (not shown) extending in the axial direction thereof and communicating with the axial oil passage 205, and the oil pressure supplied to the axial oil passage 205 is supplied to the movable sheave through the distribution oil passage.

In this structure, both ends of the case oil passage 213 are closed by the seal bolts 215 and 216, which creates the problem of high costs.

The object of the present invention is to provide a hydraulic supply structure that can reduce costs.

In order to achieve the above object, the hydraulic supply structure of the present invention is a structure for supplying hydraulic pressure to a part requiring hydraulic pressure, in which a first oil passage and a second oil passage are formed in an oil passage forming member, the second oil passage intersects with the first oil passage, the first oil passage and the second oil passage are connected, the first oil passage extends to one side from an intersection with the second oil passage, one end of the first oil passage is open at an end face of the oil passage forming member, a ball is set between the intersection and one end of the first oil passage, and the ball closes the portion of the first oil passage extending to one side from the intersection.

According to this configuration, a first oil passage and a second oil passage are formed in the oil passage forming member. The first oil passage and the second oil passage cross each other and communicate with each other. The first oil passage has a portion that extends from the intersection with the second oil passage to one side to the end face of the oil passage forming member, and is open at that end face. A ball is set between the intersection and the end on one side of the first oil passage, i.e., the open end, and the portion of the first oil passage extending from the intersection to one side is closed by the ball. This allows the number of parts to be reduced compared to a configuration in which that portion is closed by a seal bolt, and the cost of the oil passage supply structure to be reduced.

The oil passage forming member may be a retainer that is fixedly provided inside the case that forms the outer shell of the transmission, and in this case, it is preferable that one end of the first oil passage is positioned at a distance from the case that is smaller than the diameter of the ball.

In this configuration, the case prevents the ball from slipping out from one end of the first oil passage, making it possible to prevent the ball from slipping out.

The ball may be arranged so that a portion of the ball overlaps with the second oil passage when viewed from the direction in which the second oil passage is connected to the first oil passage. In other words, a portion of the ball may not be contained within the portion of the first oil passage that extends to one side from the intersection point, but may extend beyond the intersection point.

In this configuration, for example, when hydraulic pressure is supplied from the second oil passage through the first oil passage to a part requiring hydraulic pressure, the oil flowing from the second oil passage to the first oil passage flows along the spherical surface of the ball, thereby reducing hydraulic pressure loss.

The present invention allows for a reduction in the number of parts and costs compared to conventional hydraulic supply structures.

1 is a cross-sectional view showing a configuration of a speed change unit according to one embodiment of the present invention. FIG. 2 is a skeleton diagram illustrating the configuration of a CVT. FIG. 4 is a front view of the bearing retainer and its rear structure. 4 is a cross-sectional view of the bearing retainer taken along the line AA in FIG. 3. FIG. 1 is a cross-sectional view showing a conventional example of a structure for supplying hydraulic pressure to a movable sheave of a pulley.

The following describes in detail an embodiment of the present invention with reference to the attached drawings.

<Gear change unit>
Fig. 1 is a cross-sectional view showing the configuration of a speed change unit 1 according to an embodiment of the present invention. Note that hatching representing a cross section is omitted in the cross-sectional views from Fig. 1 onwards.

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

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

The transmission unit 1 includes a torque converter 4 and a CVT (Continuously Variable Transmission) 5 housed within a unit case 3 that forms the outer shell.

<Unit case>
The unit case 3 is divided into three parts: a first case 11, a second case 12, and a third case 13. The first case 11, the second case 12, and the third case 13 are made of, for example, an aluminum alloy, and are cast by die casting.

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

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

The front cover 21 extends in a generally circular disk shape centered on a rotation axis that extends in the longitudinal direction of the vehicle (body), and its outer peripheral end is bent toward the rear side, which is the opposite side to the engine 2 side (the side of the continuously variable transmission 42 described below). The center of the front cover 21 bulges forward. The crankshaft of the engine 2 is connected to this bulging portion so that it cannot rotate relative to the engine 2.

The pump impeller 22 is disposed behind the front cover 21. The outer peripheral end of the pump impeller 22 is connected to the outer peripheral end of the front cover 21 and is arranged 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.

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

The turbine runner 24 is fixed to the turbine hub 23. A number 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 lock-up piston 31 is generally annular, and its inner peripheral end is fitted onto the turbine hub 23, and is positioned between the front cover 21 and the turbine runner 24. When the hydraulic pressure of the engagement-side oil chamber 33 on the turbine runner 24 side relative to the lock-up piston 31 is higher than the hydraulic pressure of the release-side oil chamber 34 on the front cover 21 side, the lock-up piston 31 moves toward the front cover 21 side due to the pressure difference. When the lock-up piston 31 is pressed against the front cover 21, the pump impeller 22 and the turbine runner 24 are directly connected (lock-up on). Conversely, when the hydraulic pressure of the release-side oil chamber 34 is higher than the hydraulic pressure of the engagement-side oil chamber 33, the lock-up piston 31 moves toward the turbine runner 24 side 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.

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

When the engine torque rotates the pump impeller 22 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 torque converter 4 acts as an amplifier, and a torque greater than the engine torque is generated in the turbine runner 24.

<CVT>
The CVT 5 is housed in the second case 12 and the third 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 behind the engine 2 in a vertical orientation such that the input shaft 41 of the CVT 5 is oriented vertically and extends in the front-to-rear direction of the vehicle, and is inclined downward toward the rear.

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

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

The rear end of the input shaft 41 is rotatably supported by a mechanical oil pump 45 arranged in the second 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, a pump gear 48 arranged in the space inside the pump case 46, and a pump shaft 49 connected to the pump gear 48 so as not to rotate relative to the pump case 46. The pump cover 47 is fixed to the second case 12 and closes the space inside the pump case 46 from the rear. The front end of the pump case 46 is formed with a bearing recess 51 that is open to the front and recessed in a roughly cylindrical shape to the rear. The rear end of the input shaft 41 is inserted into the bearing recess 51 and rotatably supported by the pump case 46 via a ball bearing 52 interposed between the circumferential surface of the input shaft 41 and the inner circumferential surface of the bearing recess 51. In other words, a 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 rotatably supported by the pump case 46 via the ball bearing 52.

The pump shaft 49 is disposed 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 it and its inner peripheral surface. 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 not to rotate relative to it. As a result, when the front cover 21 rotates due to the power of the engine 2, the pump shaft 49 and pump gear 48 rotate integrally 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 secondary shaft 55 extend parallel to the input shaft 41 between the first case 11 and the second case 12 and are rotatable about their respective axes.

The primary pulley 56 includes a primary fixed sheave 61 fixed to the primary shaft 54, and a primary movable sheave 62 arranged opposite the primary fixed sheave 61 with the belt 58 in between, and supported on the primary shaft 54 so as to be movable in the axial direction but not rotatable relative to the primary shaft 54. The primary movable sheave 62 is arranged forward of the primary fixed sheave 61. A cylinder 63 is provided on the opposite side of the primary movable sheave 62 from the primary fixed sheave 61, i.e., on the forward side, and a hydraulic chamber (piston chamber) 64 is formed between the primary movable sheave 62 and the cylinder 63.

The secondary pulley 57 is equipped with a secondary fixed sheave 65 fixed to the secondary shaft 55, and a secondary movable sheave 66 arranged opposite the secondary fixed sheave 65 with the belt 58 in between, and supported on the secondary shaft 55 so as to be movable in the axial direction but not rotatable relative to the secondary shaft 55. The secondary movable sheave 66 is arranged on the rear side of 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, i.e., 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 endless and is wound around the primary pulley 56 while being sandwiched between the primary fixed sheave 61 and the primary movable sheave 62, and is wound around the secondary pulley 57 while being sandwiched between the secondary fixed sheave 65 and the secondary movable sheave 66.

In the continuously variable transmission mechanism 42, the oil pressure supplied to each of the hydraulic chambers 64, 68 of the primary pulley 56 and the secondary pulley 57 is controlled to change the groove width of each of the primary pulley 56 and the secondary pulley 57, thereby continuously and steplessly changing the belt transmission ratio (pulley ratio between the primary pulley 56 and the secondary pulley 57) within a certain transmission ratio range.

Specifically, when the belt speed ratio is reduced, the hydraulic pressure supplied to the hydraulic chamber 64 of the primary pulley 56 is increased. This causes the primary movable sheave 62 of the primary pulley 56 to move toward the primary fixed sheave 61, reducing the gap (groove width) between the primary fixed sheave 61 and the primary movable sheave 62. As a result, the winding diameter of the belt 58 around the primary pulley 56 increases, and the gap (groove width) between the secondary fixed sheave 65 and secondary movable sheave 66 of the secondary pulley 57 increases. As a result, the belt speed ratio decreases.

When the belt transmission ratio is increased, the hydraulic pressure supplied to the hydraulic chamber 64 of the primary pulley 56 is reduced. This makes the thrust of the secondary pulley 57 against the belt 58 greater than the thrust of the primary pulley 56 against the belt 58, reducing the gap between the secondary fixed sheave 65 and secondary movable sheave 66 of the secondary pulley 57 and increasing the gap between the primary fixed sheave 61 and primary movable sheave 62. As a result, the belt transmission ratio increases.

A bias spring 69 is provided in the hydraulic chamber 68 of the secondary pulley 57. One end of the bias spring 69 elastically contacts the secondary movable sheave 66, and the other end of the bias spring 69 elastically contacts the piston 67. The elastic force of the bias spring 69 biases the secondary movable sheave 66 and the piston 67 in directions that move them away from each other. The hydraulic pressure in the hydraulic chamber 68 and the biasing force of the bias spring 69 are applied to the secondary movable sheave 66, and a corresponding clamping pressure is applied to the belt 58.

An input gear 81 is formed integrally with 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 capable of relative rotation. A forward clutch 83 is provided that allows/prohibits rotation of the primary input gear 82 relative to the primary shaft 54, utilizing the space between the oil pump 45 and the input gear 81 and primary input gear 82 that mesh with each other. A portion of the forward clutch 83 overlaps with the oil pump 45 in the axial direction (overlaps when viewed in the axial direction).

The forward clutch 83 includes a clutch drum 84, a clutch hub 85, and a clutch piston 86. The inner peripheral end of the clutch drum 84 is fixed to the primary shaft 54, extends from the primary shaft 54 in the axial direction, and the outer peripheral end is bent and extends toward the primary input gear 82, i.e., the front side. The clutch hub 85 is formed integrally with the primary input gear 82, has a cylindrical shape extending rearward from the primary input gear 82, and faces the outer peripheral end of the clutch drum 84 from the inside in the axial direction with a gap therebetween. The clutch piston 86 is provided between the clutch drum 84 and the clutch hub 85 so as to be movable in the axial direction. The clutch piston 86 is in liquid-tight contact with the clutch drum 84, and a hydraulic chamber 87 is formed between the clutch drum 84 and the clutch piston 86 to which hydraulic pressure acting on the clutch piston 86 is supplied. The clutch piston 86 is elastically biased rearward by a return spring 88.

In the space between the outer circumferential end of the clutch drum 84 and the clutch hub 85 in the axial direction, the clutch plates held by the clutch drum 84 and the clutch discs held by the clutch hub 85 are arranged alternately in the axial direction. When the clutch piston 86 moves forward and presses the clutch plates from the rear due to the hydraulic pressure supplied to the hydraulic chamber 87, the clutch plates and the clutch discs are pressed together, and the forward clutch 83 is engaged. When the forward clutch 83 is engaged, the primary input gear 82 is prohibited from rotating relative to the primary shaft 54, and when the primary input gear 82 rotates, the primary shaft 54 rotates together with the 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 discs and the clutch plates is released, and the forward clutch 83 is released. By releasing the forward clutch 83, the primary input gear 82 is allowed to rotate relative to the primary shaft 54, and even if the primary input gear 82 rotates, the rotation is not transmitted to the primary shaft 54.

A secondary input gear 91 is supported on the secondary shaft 55 so as to be capable of relative rotation. The secondary input gear 91 is disposed between the input gear 81 and the oil pump 45 in the axial direction. In addition, a reverse clutch 92 is provided that utilizes the space between the secondary input gear 91 and the oil pump 45 to permit/prohibit rotation of the secondary input gear 91 relative to the secondary shaft 55. A portion of the reverse clutch 92 overlaps with the oil pump 45 in the axial direction (overlaps when viewed in the axial direction).

The reverse clutch 92 includes a clutch drum 93, a clutch hub 94, and a clutch piston 95. The inner peripheral end of the clutch drum 93 is fixed to the secondary shaft 55, extends from the secondary shaft 55 in the axial direction, and the outer peripheral end is bent and extends toward the secondary input gear 91, i.e., 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 faces the outer peripheral end of the clutch drum 93 from the inside in the axial direction with a gap therebetween. The clutch piston 95 is provided between the clutch drum 93 and the clutch hub 94 so as to be movable in the axial direction. The clutch piston 95 is in liquid-tight contact with the clutch drum 93, and a hydraulic chamber 96 is formed between the clutch drum 93 and the clutch piston 95 to which hydraulic pressure acting on the clutch piston 95 is supplied. The clutch piston 95 is elastically biased rearward by a return spring 97.

In the space between the outer circumferential end of the clutch drum 93 and the clutch hub 94 in the axial direction, the clutch plates held by the clutch drum 93 and the clutch discs held by the clutch hub 94 are arranged alternately in the axial direction. When the clutch piston 95 moves forward and presses the clutch plates from the rear due to the hydraulic pressure supplied to the hydraulic chamber 96, the clutch plates and the clutch discs are pressed together, and the reverse clutch 92 is engaged. When the reverse clutch 92 is engaged, the secondary input gear 91 is prohibited from rotating relative to the secondary shaft 55, 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 discs and the clutch plates is released, and the reverse clutch 92 is released. When the reverse clutch 92 is released, the secondary input gear 91 is allowed to rotate relative to the secondary shaft 55, and even if the secondary input gear 91 rotates, the rotation is not transmitted to the secondary shaft 55.

The output shaft 43 is spaced rearward from the input shaft 41 and is arranged coaxially with the input shaft 41. In other words, the input shaft 41 and the output shaft 43 are arranged to have a common axis that extends vertically along the front-rear direction of the vehicle, with a gap in the axial direction. An output transmission gear 101 is integrally formed on 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 rotate relative to the input shaft 41.

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

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

The bearing retainer 111 also has a recess 115 formed on the rear side that is recessed into a generally cylindrical shape. The rear end 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. The rear end of the primary shaft 54 is rotatably supported by the bearing retainer 111 via the ball bearing 116.

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

<Oil supply>
A valve body 121 for controlling the supply of oil to each part of the transmission unit 1 is provided at the bottom of the second case 12 .

A strainer 122 is provided at the bottom of the second case 12. The strainer 122 includes a filtering section 123 arranged side by side with the valve body 121, and a pipe section 124 extending from the filtering section 123. The pipe section 124 extends forward from the lower portion of the filtering section 123 and below the valve body 121. The pipe section 124 is formed in a hollow tubular shape that communicates with the inside of the filtering section 123.

The oil pan 125 is fixed to the second case 12 from below with multiple bolts 126. The tip 127 of the tube 124 of the strainer 122 is located in the center of the oil pan 125, and an inlet port for sucking oil is formed on the underside of the tip 127.

The rotation of the pump gear 48 of the oil pump 45 generates a suction force, which draws the oil stored in the oil pan 125 into the pipe section 124 through the suction port. The oil drawn into the pipe section 124 flows through the pipe section 124 toward the filter section 123 and passes through the filter material provided in the filter section 123. As the oil passes through the filter material, foreign matter contained in the oil is captured by the filter material 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. The oil is then supplied from the valve body 121 to each part that requires a supply of oil, such as the continuously variable transmission 42, as hydraulic oil or lubricating oil.

<Power transmission path>
FIG. 2 is a skeleton diagram illustrating 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. The 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 due to the engagement of the forward clutch 83. On the other hand, even if the power input to the input shaft 41 is transmitted from the input gear 81 to the secondary input gear 91 and the secondary input gear 91 rotates, the secondary input gear 91 rotates freely relative to the secondary shaft 55 due to the release of the reverse clutch 92, and no power is transmitted to the secondary shaft 55.

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

When the vehicle is moving backwards, the forward clutch 83 is released and the reverse clutch 92 is engaged. The power input from the engine 2 to the input shaft 41 via the torque converter 4 is transmitted from the input gear 81 to the secondary shaft 55 via the reverse transmission mechanism 44 and the secondary input gear 91 by the engagement of the reverse clutch 92. At this time, the secondary shaft 55 rotates in the opposite direction to when the vehicle is moving forward. On the other hand, even if the power input to the input shaft 41 is transmitted from the input gear 81 to the primary input gear 82 and the primary input gear 82 rotates, the primary input gear 82 rotates freely relative to the primary shaft 54 due to the release of the forward clutch 83, 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 then output from the output shaft 43 to the propeller shaft, and is then transmitted from the propeller shaft to the left and right rear wheels via the rear differential gear (rear diff) and the drive shafts.

<Hydraulic supply structure>
As shown in FIG. 1, the primary shaft 54 is formed with a primary axial center oil passage 131 extending on its axis (center line). The primary axial center oil passage 131 is open at the rear end face of the primary shaft 54. The primary shaft 54 is also formed with radial oil passages 132, 133 extending in the axial direction at intervals from each other in the axial direction. One end of each of the radial oil passages 132, 133 is connected to the primary axial center oil passage 131, and the radial oil passages 132, 133 communicate with the primary axial center oil passage 131. The other end of the radial oil passage 132 is open at the outer circumferential surface of the primary shaft 54. The primary moving sheave 62 is formed with a substantially cylindrical outer fitting portion 134 that is fitted onto the primary shaft 54, and a communication oil passage 165 is formed to pass through the outer fitting portion 134. Depending on the position of the primary movable sheave 62, only the radial oil passage 132 communicates with the hydraulic chamber 64 of the primary pulley 56, only the radial oil passage 133 communicates with the hydraulic chamber 64 via the communicating oil passage 165, or both the radial oil passages 132 and 133 communicate with the hydraulic chamber 64.

Figure 3 is a front view of the bearing retainer 111 and the rear structure. Figure 4 is a cross-sectional view of the bearing retainer 111 taken along the line A-A in Figure 3.

The bearing retainer 111 has a retainer oil passage 141 that extends linearly from the center of the recess 115 toward the lower left. The lower end 142 of the retainer oil passage 141 is an open end that opens at the peripheral end surface 143 of the bearing retainer 111.

The bearing retainer 111 is formed with a generally cylindrical insert 151 that extends along the center line of the recess 115 and protrudes forward. As shown in FIG. 1, a plug 152 is fitted to the insert 151. An O-ring is provided on the outer periphery of the plug 152. The insert 151 is inserted into the primary axial oil passage 131 from the rear side of the primary shaft 54, and the O-ring of the plug 152 abuts liquid-tightly against the peripheral surface of the primary axial oil passage 131, thereby sealing the gap between the plug 152 and the peripheral surface of the primary axial oil passage 131. The hollow portion of the insert 151 forms an introduction oil passage 153. The introduction oil passage 153 communicates with the primary axial oil passage 131 via the plug 152, and is connected to the retainer oil passage 141 as shown in FIG. 4, and communicates with the retainer oil passage 141.

A connecting oil passage 154 is formed in the lower part of the bearing retainer 111, extending in the axial direction. The front end of the connecting oil passage 154 is open at the front surface of the bearing retainer 111. The rear end of the connecting oil passage 154 is connected to the retainer oil passage 141 with a gap between it and the lower end 142 of the retainer oil passage 141. As a result, the retainer oil passage 141 and the connecting oil passage 154 cross (are perpendicular) at 90° and communicate with each other.

A ball 157 with a diameter slightly larger than the inner diameter of the retainer oil passage 141 is pressed into the closed portion 156 between the lower end 142 and an intersection 155 of the retainer oil passage 141 with the connecting oil passage 154. The closed portion 156 of the retainer oil passage 141 is closed between the intersection 155 and the lower end 142 by the ball 157. The distance between the lower end 142 of the retainer oil passage 141 and the rear end of the connecting oil passage 154 is smaller than the diameter of the ball 157, and a part of the ball 157 does not fit into the closed portion 156 and protrudes into the intersection 155.

The hydraulic pressure is supplied to the connection oil passage 154 from the valve body 121. The hydraulic pressure supplied to the connection oil passage 154 is supplied to the primary axial oil passage 131 of the primary shaft 54 via the retainer oil passage 141 and the introduction oil passage 153. The hydraulic pressure supplied to the primary axial oil passage 131 is then supplied to the hydraulic chamber 64 of the primary pulley 56 from the primary axial oil passage 131 via the radial oil passages 132 and 133 of the primary shaft 54.

The third case 13 of the unit case 3 is formed with a wraparound portion 161. The wraparound portion 161 wraps around the underside of the peripheral end face 143 of the bearing retainer 111 and extends with a gap smaller than the diameter of the peripheral end face 143 and the ball 157.

<Action and effect>
As described above, the bearing retainer 111 is formed with the retainer oil passage 141 as an example of a first oil passage and the connecting oil passage 154 as an example of a second oil passage. The retainer oil passage 141 and the connecting oil passage 154 cross each other and communicate with each other. The retainer oil passage 141 has a portion extending from the intersection 155 with the connecting oil passage 154 to the peripheral end surface 143 of the bearing retainer 111 on one side, and is open at the peripheral end surface 143. A ball 157 is set in the closed portion 156 between the intersection 155 and the lower end 142, which is the open end of the retainer oil passage 141, and the closed portion 156 is closed by the ball 157. This allows the number of parts to be reduced compared to a configuration in which the closed portion 156 is closed by a seal bolt, and the cost of the gear shift unit 1 in which such a structure is adopted can be reduced.

The bearing retainer 111 is fixedly provided in the unit case 3, which forms the outer shell of the transmission unit 1. The lower end 142 of the retainer oil passage 141 is disposed at a position spaced apart from the wraparound portion 161 of the third case 13 of the unit case 3 by a distance smaller than the diameter of the ball 157. With this configuration, the wraparound portion 161 of the third case 13 prevents the ball 157 from slipping out of the lower end 142 of the retainer oil passage 141, preventing the ball 157 from slipping out.

A part of the ball 157 does not fit in the part of the retainer oil passage 141 that extends from the intersection 155 to one side, but protrudes beyond the intersection 155. As a result, the ball 157 is arranged so that a part of it overlaps with the connection oil passage 154 when viewed from the direction in which the connection oil passage 154 is connected to the retainer oil passage 141. In this configuration, the oil flowing from the connection oil passage 154 to the retainer oil passage 141 flows along the spherical surface of the ball 157, so that a smooth flow of oil can be ensured at the intersection 155, and hydraulic loss can be reduced. As a result, the belt speed change ratio (pulley ratio) of the continuously variable transmission mechanism 42 of the transmission unit 1 can be smoothly changed, and the fuel efficiency of the vehicle in which the transmission unit 1 is installed can be improved.

<Modification>

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

In addition, the power transmission system of the continuously variable transmission mechanism 42 is not limited to a 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.

The present invention is not limited to the transmission unit 1, and may be applied to hydraulic supply structures in devices other than transmissions mounted on vehicles.

In addition, various design modifications may be made to the above-mentioned configuration within the scope of the claims.

3: Unit case (case)
13: Third Case (Case)
62: Primary movable sheave (part requiring hydraulic pressure)
64: Hydraulic chamber (part requiring hydraulic pressure)
111: Bearing retainer (oil passage forming member)
141: Retainer oil path (first oil path)
142: Bottom end (end on one side)
143: Peripheral end face (end face)
154: Connection oil path (second oil path)
155: Intersection 156: Closed section (section extending to one side from the intersection)
157: Ball 161: Wrapping part (case)

Claims (2)

A structure for supplying hydraulic pressure to a part requiring hydraulic pressure,
The first oil passage, the second oil passage, and the third oil passage are formed in an oil passage forming member,
The second oil passage intersects the first oil passage, and the first oil passage and the second oil passage communicate with each other.
The first oil passage extends linearly from an intersection with the second oil passage to one side in a direction intersecting with the second oil passage and to the other side opposite thereto,
The third oil passage is connected to the first oil passage at a point away from the intersection on the other side,
The one end of the first oil passage is opened at an end surface of the oil passage forming member, and the other end of the first oil passage is closed by the oil passage forming member,
a ball is set between the intersection and the end of the first oil passage on the one side, and a portion of the first oil passage extending from the intersection to the one side is closed by the ball ;
The oil passage forming member is a retainer that is fixedly provided in a case that forms an outer shell of the transmission, and is fixed to the case.
The case has a wraparound portion formed therein,
The wraparound portion wraps around below the end of the one side of the first oil passage,
A hydraulic pressure supply structure , wherein the end on the one side of the first oil passage is disposed at a position spaced from the wraparound portion by a distance smaller than a diameter of the ball. 2 . The hydraulic pressure supply structure according to claim 1 , wherein the ball is disposed so that a portion of the ball overlaps with the second oil passage when viewed from a direction in which the second oil passage is connected to the first oil passage.

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