JP7204306B2 - transmission - Google Patents

Description

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

Conventionally, in a transmission such as a CVT (Continuously Variable Transmission), a valve body for controlling the supply of oil to each part is arranged at the bottom of the case that forms the outer shell. The pan is bolted from the underside of the valve body. A strainer is arranged between the valve body and the oil pan for sucking up the oil stored in the oil pan and supplying it to the valve body.

It is necessary to take oil from the center of the oil pan into the strainer in consideration of the behavior of the oil (changes in the oil surface position of the oil stored in the oil pan) due to turning, starting, and stopping of the vehicle equipped with the transmission. There is Therefore, the strainer is arranged below the valve body, and the suction port for sucking oil into the strainer is formed at a position facing the central portion of the oil pan.

JP 2017-180711 A

However, in this configuration, the size of the transmission in the vertical direction becomes large, making it difficult to mount the transmission on a compact vehicle.

SUMMARY OF THE INVENTION An object of the present invention is to provide a transmission that can be reduced in size in the vertical direction.

In order to achieve the above object, the transmission according to the present invention comprises a case forming an outer shell, a speed change mechanism supported by the case, which shifts power input to an input shaft and transmits the power to an output shaft, A valve body that supplies oil to the transmission mechanism, an oil pan that is attached to the case from the bottom of the valve body and stores the oil, and the oil accumulated in the oil pan is sucked from the suction port and supplied to the valve body through the filter material. The valve body is arranged below the speed change mechanism, and the strainer has a main body portion in which filtering material is accommodated and a pipe portion through which oil sucked from the suction port flows toward the main body portion. the body portion is arranged side by side with the valve body; the pipe portion extends from the body portion and extends under the valve body; facing each other.

According to this configuration, the strainer has a main body portion in which the filtering material is accommodated, and a pipe portion in which the suction port is formed. Since the tube portion does not accommodate the filtering material, the tube portion can be formed thinner than the main body portion. Therefore, compared to a structure in which the main body is arranged side by side with the valve body and the pipe extends from the main body and extends below the valve body, the strainer is arranged below the valve body. It is possible to reduce the vertical size of the transmission. Moreover, since the suction port is formed at a position facing the center of the oil pan, the oil accumulated in the oil pan can be sucked regardless of the behavior of the oil due to turning, starting, or stopping of the vehicle on which the transmission is mounted. It can be well sucked into the strainer (inside the tube) from the mouth.

The transmission mechanism has a primary shaft and a secondary shaft that extend parallel to the input shaft, respectively, and is a continuously variable transmission mechanism that transmits power from the primary shaft to the secondary shaft while changing the speed. When viewed from the axial direction, the input shaft is divided into left and right sides, one of which is positioned higher than the other, the valve body is positioned below one of the primary and secondary shafts, and the strainer is , under the other of the primary axis and the secondary axis.

In this configuration, the primary shaft and the secondary shaft are arranged separately on the left and right sides of the input shaft when viewed from the axial direction of the input shaft. Thereby, the distance between the primary shaft and the secondary shaft in the vertical direction can be shortened. As a result, the vertical size of the transmission can be further reduced. Furthermore, one of the primary shaft and the secondary shaft is positioned higher than the other, and a valve body relatively large in the vertical direction is arranged below one of them, and below the other. , strainers with a relatively small size in the vertical direction are arranged. With this layout, it is possible to further reduce the vertical size of the transmission.

As a result, even in a vehicle such as a commercial vehicle having a low-floor cabin, it is possible to mount the transmission on the vehicle while ensuring the minimum ground clearance of the vehicle.

According to the present invention, it is possible to reduce the vertical size of the transmission.

1 is a cross-sectional view showing the configuration of a transmission unit according to one embodiment of the present invention; FIG. FIG. 2 is a cross-sectional view showing an enlarged part of a transmission unit extracted from FIG. 1; It is the figure which looked at the inside of the 2nd case of the transmission unit from the rear side (engine side and opposite side). FIG. 4 is a diagram showing the configuration inside the second case, and is a view of the configuration inside the second case as seen from the rear side. It is the figure which looked at the part containing the 2nd case in a transmission unit from the lower side. It is the figure which looked at the strainer from the front side. 1 is a skeleton diagram showing a power transmission path in a CVT together with the configuration of the CVT; FIG.

BEST MODE FOR CARRYING OUT THE INVENTION Below, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<Transmission unit>
FIG. 1 is a cross-sectional view showing the configuration of a transmission unit 1 according to one embodiment of the invention. FIG. 2 is a cross-sectional view showing a portion of the transmission unit 1 extracted from FIG. 1 and enlarged. In addition, in the cross-sectional views of FIG. 1 and subsequent drawings, the hatching representing the cross-section is omitted.

The transmission unit 1 is mounted on a vehicle and is a unit that changes the speed of power generated by an engine (E/G) as a drive source for running. The vehicle adopts an FR layout, and the engine is, for example, a 3-cylinder 4-stroke engine. The transmission unit 1 includes a torque converter 3 and a CVT 4 inside a unit case 2 forming an outer shell.

In the following, a case where the engine is a 3-cylinder 4-stroke engine will be taken up, but the number of cylinders of the engine is not limited to 3, and may be 4 or more or 2 or less. Further, the number of strokes of the engine is not limited to 4 strokes, and may be 2 strokes.

<Unit case>
The unit case 2 is composed of a first case 11 , a second case 12 and a third case 13 divided into three parts. The first case 11, the second case 12 and the third case 13 are made of, for example, an aluminum alloy and 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 side), and the first case 11 and the second case 12 are fastened with bolts (not shown). The second case 12 and the third case 13 are integrated by fastening with bolts 14 . Torque converter 3 is housed in first case 11 , and CVT 4 is housed in second case 12 and third case 13 .

<Torque converter>
The torque converter 3 has 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 disc shape around a rotation axis extending in the front-rear direction of the vehicle (vehicle body), and its outer peripheral end portion is on the rear side opposite to the engine side (on the side of the continuously variable transmission mechanism 42 to be described later). It has a curved shape. A central portion of the front cover 21 bulges forward. A crankshaft of the engine is coupled to this bulging portion so as not to rotate relative to it.

The pump impeller 22 is arranged behind the front cover 21 . An outer peripheral end portion of the pump impeller 22 is connected to an outer peripheral end portion of the front cover 21 so as to be integrally rotatable 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 has a lockup piston 31 and a damper mechanism 32 .

The lockup piston 31 has a substantially annular plate shape, and its inner peripheral end portion is fitted onto the turbine hub 23 to be 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 with respect to the lockup piston 31 is higher than the hydraulic pressure of the release side oil chamber 34 on the front cover 21 side, the lockup piston 31 moves toward the front cover. Move to 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 connected (locked on). Conversely, when the hydraulic pressure in the release side oil chamber 34 is higher than the hydraulic 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 lockup piston 31 is separated from the front cover 21, the direct connection between the pump impeller 22 and the turbine runner 24 is released (lockup off).

The damper mechanism 32 is a mechanism for damping vibrations from the engine 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 engine torque rotates the pump impeller 22 in the lockup 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 to rotate the turbine runner 24 . At this time, an amplifying action of the torque converter 3 occurs, and torque larger than the engine torque is generated in the turbine runner 24 .

<Vertical CVT>
The CVT 4 has an input shaft 41 , a continuously variable transmission mechanism 42 , a reverse transmission mechanism 43 and an output shaft 44 . The CVT 4 is arranged such that the input shaft 41 extends vertically in the longitudinal direction of the vehicle. That is, the CVT 4 is a so-called vertical CVT.

The input shaft 41 is formed as a hollow shaft and extends along the rotational axis of the torque converter 3 . A front end of the input shaft 41 is inserted into the torque converter 3 and spline-fitted with the turbine hub 23 .

An axial center portion of the input shaft 41 is rotatably supported by the first case 11 via a bearing 45 .

A mechanical oil pump 46 is arranged on the rear side of the input shaft 41 (the side opposite to the engine side). The oil pump 46 includes a pump case 47 and a pump cover 48 overlapping the pump case 47 . The pump case 47 and the pump cover 48 are fastened with a plurality of bolts and held by the second case 12 . A space surrounded by the pump case 47 and the pump cover 48 accommodates a pump gear 49 .

The pump case 47 is arranged on the front side with respect to the pump cover 48 . As shown in FIG. 2, the front end of the pump case 47 is formed with a circular recess 51 recessed rearward. A rear end of the input shaft 41 is inserted into the recess 51 . A needle bearing 52 is interposed between the peripheral surface of the input shaft 41 and the inner peripheral surface of the recess 51, and a thrust bearing 53 is interposed between the end surface of the input shaft 41 and the bottom surface of the recess 51. . Thereby, the rear end of the input shaft 41 is rotatably supported by the pump case 47 via the needle bearing 52 and the thrust bearing 53 .

One end of a pump shaft 54 is connected to the pump gear 49 so as to be relatively non-rotatable, as shown in FIG. The pump shaft 54 protrudes forward from the pump case 47 through the central portion of the recess 51 and is inserted through the hollow portion of the input shaft 41 with a gap between it and the inner peripheral surface of the input shaft 41 . A front end portion of the pump shaft 54 is inserted into a central portion of the front cover 21 of the torque converter 3 that bulges forward and is coupled to the front cover 21 so as not to rotate relative to the front cover 21 . As a result, when the front cover 21 rotates by the power of the engine, the pump shaft 54 and the pump gear 49 rotate together with the front cover 21 , and hydraulic pressure is generated from the oil pump 46 .

Further, the input shaft 41 is rotatably supported by the first case 11 via bearings 45 and rotatably supported by the pump case 47 via needle bearings 52 and thrust bearings 53, and is a turbine hub of the torque converter 3. 23, when the turbine runner 24 rotates, it rotates integrally with the turbine runner 24.例文帳に追加

The continuously variable transmission mechanism 42 has a primary shaft 61 , a secondary shaft 62 , a primary pulley 63 , a secondary pulley 64 and a belt 65 .

FIG. 3 is a view of the inside of the second case 12 as seen from the rear side. 1 is a cross-sectional view of the transmission unit 1 cut along the cutting line AA shown in FIG.

The primary shaft 61 extends parallel to the input shaft 41 with its axis spaced from the axis of the input shaft 41 in the lower right direction when viewed from the rear side of the vehicle. The axial distance between the input shaft 41 and the primary shaft 61, in other words, the axial radial direction (rotational radial direction) distance between the axis of the input shaft 41 and the primary shaft 61 is determined by the turbine runner of the torque converter 3. Shorter than 24 turning radius.

The secondary shaft 62 extends parallel to the input shaft 41 with its axis spaced apart from the axis of the input shaft 41 to the upper left when viewed from the rear side of the vehicle. The axial distance between the input shaft 41 and the secondary shaft 62 , in other words, the radial distance between the axis of the input shaft 41 and the axis of the secondary shaft 62 is the axis of the input shaft 41 and the axis of the primary shaft 61 . and is shorter than the turning radius of the turbine runner 24 of the torque converter 3 .

In this manner, the primary shaft 61 and the secondary shaft 62 are arranged separately on the left and right with respect to the input shaft 41 . Thereby, the distance between the primary shaft 61 and the secondary shaft 62 in the vertical direction can be shortened, and the size of the CVT 4 in the vertical direction can be reduced. In transmission unit 1 , the vertical positions of primary shaft 61 and secondary shaft 62 are between the uppermost and lowermost positions of torque converter 3 , and primary shaft 61 and secondary shaft 62 are aligned with turbine runner 24 of torque converter 3 . The size in the vertical direction of the continuously variable transmission mechanism 42 is reduced to such an extent that they face each other in the front-rear direction. Therefore, even in a vehicle such as a commercial vehicle having a low-floor cabin, it is possible to mount the transmission unit 1 on the vehicle while ensuring the minimum ground clearance of the vehicle.

The primary shaft 61 and the secondary shaft 62 are offset to one side and the other side in the vertical direction, respectively, with respect to the input shaft 41 . Specifically, in the CVT 4 , the primary shaft 61 is arranged below the input shaft 41 and the secondary shaft 62 is arranged above the input shaft 41 . As a result, the second case 12 has a portion recessed toward the primary shaft 61 with respect to the rear end portion (the portion facing the primary pulley 63 in the radial direction of rotation) at a position above and to the right of the primary shaft 61 . there is A starter ST for starting the engine is arranged in the space provided by the recessed portion.

As shown in FIG. 1, the primary pulley 63 is disposed opposite to the primary fixed sheave 71 fixed to the primary shaft 61 with the belt 65 interposed therebetween, and is movable along the axial direction of the primary shaft 61. and a primary movable sheave 72 supported so as not to rotate relative to each other. The primary movable sheave 72 is arranged on the front side with respect to the primary fixed sheave 71 .

A cylinder 73 is provided on the side opposite to the primary fixed sheave 71 side with respect to the primary movable sheave 72 , that is, on the front side. The cylinder 73 has an inner peripheral end fixed to the primary shaft 61, extends in the axial radial direction from the primary shaft 61, and an outer peripheral end bent and extending rearward. The outer peripheral end of the primary movable sheave 72 is in liquid-tight contact with the outer peripheral end of the cylinder 73 from the inner side in the radial direction of rotation. A hydraulic chamber (piston chamber) 74 is formed between the primary movable sheave 72 and the cylinder 73 .

The secondary pulley 64 is arranged opposite to the secondary fixed sheave 75 fixed to the secondary shaft 62 with the belt 65 interposed therebetween, and is supported by the secondary shaft 62 so as to be movable in the axial direction thereof and not relatively rotatable. A secondary movable sheave 76 is provided. The secondary movable sheave 76 is arranged on the rear side with respect to the secondary fixed sheave 75, and the positional relationship between the secondary fixed sheave 75 and the secondary movable sheave 76 in the front-rear direction is the same as that of the primary fixed sheave 71 of the primary pulley 63 and the primary fixed sheave 71 of the primary pulley 63. The positional relationship with the movable sheave 72 is reversed.

A piston 77 is provided on the side opposite to the secondary fixed sheave 75 with respect to the secondary movable sheave 76 , that is, on the rear side. The piston 77 has an inner peripheral end fixed to the secondary shaft 62 and extends radially from the secondary shaft 62 . The outer peripheral end of the secondary movable sheave 76 extends rearward, and the outer peripheral end of the piston 77 liquid-tightly contacts the outer peripheral end of the secondary movable sheave 76 from the inner side in the radial direction of rotation. A hydraulic chamber 78 is formed between the secondary movable sheave 76 and the piston 77 .

The secondary fixed sheave 75 and the secondary movable sheave 76 of the secondary pulley 64 overlap the primary movable sheave 72 and part of the cylinder 73 in the vertical direction (they overlap when viewed in the front-rear direction). Specifically, the outer peripheral end of the primary movable sheave 72 extends in the front-rear direction and the front end thereof is bent outward in the radial direction of rotation. It faces the portion extending in the front-rear direction from the outside in the radial direction of rotation, and faces the portion extending in the radial direction of rotation at the outer peripheral end thereof from the rear side.

In the continuously variable transmission mechanism 42, the hydraulic pressure supplied to the hydraulic chambers 74, 78 of the primary pulley 63 and the secondary pulley 64 is controlled to change the groove widths of the primary pulley 63 and the secondary pulley 64, whereby the belt is The gear ratio (the pulley ratio between the primary pulley 63 and the secondary pulley 64) is continuously and steplessly changed within a fixed gear ratio range.

Specifically, when the belt gear ratio is decreased, the hydraulic pressure supplied to the hydraulic chamber 74 of the primary pulley 63 is increased. As a result, the primary movable sheave 72 of the primary pulley 63 moves toward the primary fixed sheave 71, and the gap (groove width) between the primary fixed sheave 71 and the primary movable sheave 72 becomes smaller. Accordingly, the winding diameter of the belt 65 around the primary pulley 63 increases, and the interval (groove width) between the secondary fixed sheave 75 and the secondary movable sheave 76 of the secondary pulley 64 increases. As a result, the belt transmission ratio becomes smaller.

When the belt gear ratio is increased, the hydraulic pressure supplied to the hydraulic chamber 74 of the primary pulley 63 is decreased. As a result, the thrust of the secondary pulley 64 against the belt 65 becomes greater than the thrust of the primary pulley 63 against the belt 65 , the distance between the secondary fixed sheave 75 and the secondary movable sheave 76 of the secondary pulley 64 becomes smaller, and the primary fixed sheave 71 becomes smaller. and the primary movable sheave 72 becomes larger. As a result, the belt transmission ratio is increased.

A bias spring 79 is provided in the hydraulic chamber 78 of the secondary pulley 64 . One end of the bias spring 79 elastically contacts the secondary movable sheave 76 and the other end elastically contacts the piston 77 . The elastic force of the bias spring 79 urges the secondary movable sheave 76 and the piston 77 away from each other. The secondary movable sheave 76 is applied with hydraulic pressure in the hydraulic chamber 68 and biasing force by the bias spring 79 , and the belt 65 is applied with a corresponding clamping pressure.

The primary shaft 61 is divided into a first primary shaft 81 and a second primary shaft 82 . The first primary shaft 81 is arranged in front of the second primary shaft 82 . Primary pulley 63 is supported by second primary shaft 82 . A circular connection recess 83 is formed at the rear end of the first primary shaft 81 . The front end of the second primary shaft 82 is inserted into the connection recess 83 , and the outer peripheral surface of the second primary shaft 82 is spline-fitted with the inner peripheral surface of the connection recess 83 in the connection recess 83 . . A front end portion of the first primary shaft 81 is rotatably supported by the first case 11 via a bearing 84 . A front end of the second primary shaft 82 is rotatably supported by the second case 12 via a bearing 85 . An adapter 86 fixedly held by the second case 12 is arranged behind the primary pulley 63 , and the rear end of the second primary shaft 82 rotates around the adapter 86 via a bearing 87 . supported as possible.

As shown in FIG. 2, the input shaft 41 is integrally formed with an input shaft gear 91 at a portion adjacent to the rear side of the portion where the inner race of the bearing 45 is fitted. Correspondingly, a primary input gear 92 is rotatably supported on the first primary shaft 81 via a needle bearing 93 . The primary input gear 92 meshes with the input shaft gear 91 and has a larger gear diameter than the input shaft gear 91 .

A forward clutch 94 that permits/prohibits rotation of the primary input gear 92 with respect to the first primary shaft 81 by utilizing the space between the input shaft gear 91 and the primary input gear 92 that mesh with each other and the pump case 47 of the oil pump 46. is provided. A portion of the forward clutch 94 overlaps the oil pump 46 in the rotational radial direction (overlapping when viewed in the rotational axis direction). Forward clutch 94 includes clutch drum 95 , clutch hub 96 , clutch piston 97 and canceller 98 .

The clutch drum 95 has an inner peripheral end fixed to the first primary shaft 81, extends radially from the first primary shaft 81, and an outer peripheral end bends toward the primary input gear 92, that is, extends forward. A plurality of clutch plates 101 are arranged and held at intervals in the front-rear direction at the outer peripheral end of the clutch drum 95 .

Clutch hub 96 is formed integrally with primary input gear 92 . The clutch hub 96 has a cylindrical shape extending rearward from the primary input gear 92 and faces the outer peripheral end portion of the clutch drum 95 from the inside in the radial direction of rotation with a gap therebetween. A plurality of clutch discs 102 are held on the clutch hub 96 at intervals in the front-rear direction. The clutch plates 101 and the clutch discs 102 are arranged alternately in the central axis direction.

The clutch piston 97 is provided between the clutch drum 95 and the clutch hub 96 so as to be movable in the axial direction of the first primary shaft 81, that is, in the longitudinal direction. The clutch piston 97 extends from the first primary shaft 81 radially outwardly of the first primary shaft 81 and extends with its outer peripheral end bent forward. The tip of the outer peripheral end of the clutch piston 97 contacts the clutch plate 101 . In addition, the clutch piston 97 is in liquid-tight contact with the clutch drum 95, and a hydraulic chamber 103 is formed between the clutch drum 95 and the clutch piston 97 to supply hydraulic pressure acting on the clutch piston 97. ing.

Canceller 98 is provided between clutch hub 96 and clutch piston 97 . An inner peripheral end of the canceller 98 is fixed to the first primary shaft 81 . An outer peripheral end of the canceller 98 is in liquid-tight contact with the clutch piston 97 . Thereby, a canceller chamber 104 is formed between the clutch piston 97 and the canceller 98 . A return spring 105 is provided in the canceller chamber 104 , and the clutch piston 97 and the canceller 98 are elastically biased away from each other by the biasing force of the return spring 105 .

The clutch piston 97 is moved toward the clutch plate 101 by hydraulic pressure supplied to the hydraulic chamber 103 and presses the clutch plate 101 . Due to this pressure, the clutch plate 101 and the clutch disc 102 are pressed against each other, and the forward clutch 94 is engaged. Engagement of the forward clutch 94 inhibits rotation of the primary input gear 92 with respect to the first primary shaft 81 , and when the primary input gear 92 rotates, the first primary shaft 81 rotates together with the primary input gear 92 . When the hydraulic pressure is released from the engaged state of the forward clutch 94 , the biasing force of the return spring 105 interposed between the clutch piston 97 and the canceller 98 separates the clutch piston 97 from the clutch plate 101 . As a result, the pressure contact between the clutch disc 102 and the clutch plate 101 is released, and the forward clutch 94 is released. The disengagement of the forward clutch 94 allows the rotation of the primary input gear 92 with respect to the first primary shaft 81 , and even if the primary input gear 92 rotates, the rotation is not transmitted to the first primary shaft 81 .

The secondary shaft 62 is configured by being divided into a first secondary shaft 111 and a second secondary shaft 112 . The first secondary shaft 111 is arranged in front of the second secondary shaft 112 . Secondary pulley 64 is supported by second secondary shaft 112 . A circular connection recess 113 is formed at the rear end of the first secondary shaft 111 . The front end of the second secondary shaft 112 is inserted into the connection recess 113 , and the outer peripheral surface of the second secondary shaft 112 is spline-fitted with the inner peripheral surface of the connection recess 113 in the connection recess 113 . . The first secondary shaft 111 is the same component as the first primary shaft 81 as can be understood by comparing with the first primary shaft 81 . By sharing the first primary shaft 81 and the first secondary shaft 111, it is possible to reduce the number of types of parts that constitute the transmission unit 1 (CVT 4) and reduce the manufacturing cost of the transmission unit 1. A front end portion of the first secondary shaft 111 is rotatably supported by the first case 11 via a bearing 114 . A front end of the second secondary shaft 112 is rotatably supported by the second case 12 via a bearing 115 . A rear end portion of the second secondary shaft 112 is rotatably supported by the third case 13 via a bearing 116 .

A secondary input gear 121 is rotatably supported on the second secondary shaft 112 via a needle bearing 122 on the rear side of the bearing 114 .

A space between the secondary input gear 121 and the pump case 47 of the oil pump 46 is utilized to provide a reverse clutch 123 that permits/prohibits rotation of the secondary input gear 121 relative to the first secondary shaft 111 . A portion of the reverse clutch 123 overlaps with the oil pump 46 in the rotation radial direction (overlapping when viewed in the rotation axis direction). The reverse clutch 123 has a clutch drum 124 , a clutch hub 125 , a clutch piston 126 and a canceller 127 .

The clutch drum 124 has an inner peripheral end fixed to the first secondary shaft 111, extends radially from the first secondary shaft 111, and an outer peripheral end bends toward the secondary input gear 121, that is, extends forward. A plurality of clutch plates 131 are arranged and held at intervals in the front-rear direction at the outer peripheral end of the clutch drum 124 .

Clutch hub 125 is formed integrally with secondary input gear 121 . The clutch hub 125 has a cylindrical shape extending rearward from the secondary input gear 121 and faces the outer peripheral end portion of the clutch drum 124 from the inner side in the rotation radial direction with a gap therebetween. A plurality of clutch discs 132 are held on the clutch hub 125 at intervals in the front-rear direction. The clutch plates 131 and the clutch discs 132 are arranged alternately in the central axis direction. Each number of clutch plates 131 and clutch disks 132 is greater than each number of clutch plates 101 and clutch disks 102 of forward clutch 94 .

The clutch piston 126 is provided between the clutch drum 124 and the clutch hub 125 so as to be movable in the axial direction of the first secondary shaft 111, that is, in the longitudinal direction. The clutch piston 126 extends radially outward from the first secondary shaft 111 in the axial direction of the first secondary shaft 111, and has an outer peripheral end bent forward. The tip of the outer peripheral end of clutch piston 126 contacts clutch plate 131 . In addition, the clutch piston 126 is in liquid-tight contact with the clutch drum 124, and a hydraulic chamber 133 is formed between the clutch drum 124 and the clutch piston 126 to supply the hydraulic pressure acting on the clutch piston 126. ing.

Canceller 127 is provided between clutch hub 125 and clutch piston 126 . An inner peripheral end of the canceller 127 is fixed to the first secondary shaft 111 . An outer peripheral end of the canceller 127 is in liquid-tight contact with the clutch piston 126 . Thereby, a canceller chamber 134 is formed between the clutch piston 126 and the canceller 127 . A return spring 135 is provided in the canceller chamber 134 , and the clutch piston 126 and the canceller 127 are elastically biased away from each other by the biasing force of the return spring 135 .

The clutch piston 126 is moved toward the clutch plate 131 by hydraulic pressure supplied to the hydraulic chamber 133 and presses the clutch plate 131 . Due to this pressure, the clutch plate 131 and the clutch disk 132 are pressed against each other, and the reverse clutch 123 is engaged. The engagement of the reverse clutch 123 inhibits rotation of the secondary input gear 121 with respect to the first secondary shaft 111 , and when the secondary input gear 121 rotates, the first secondary shaft 111 rotates integrally with the secondary input gear 121 . When the hydraulic pressure is released from the engaged state of the reverse clutch 123 , the biasing force of the return spring 135 interposed between the clutch piston 126 and the canceller 127 separates the clutch piston 126 from the clutch plate 131 . As a result, the pressure contact between the clutch disc 132 and the clutch plate 131 is released, and the reverse clutch 123 is released. Disengagement of reverse clutch 123 allows rotation of secondary input gear 121 with respect to first secondary shaft 111 , and rotation of secondary input gear 121 is not transmitted to first secondary shaft 111 even if secondary input gear 121 rotates.

The reverse transmission mechanism 43 is a mechanism that transmits the power (rotation) of the input shaft 41 to the secondary shaft 62 (first secondary shaft 111) without passing through the continuously variable transmission mechanism 42. Reverse transmission mechanism 43 includes a reverse idler shaft 141 , a first reverse gear 142 and a second reverse gear 143 .

The reverse idler shaft 141 extends in the front-rear direction parallel to the input shaft 41 . A front end of the reverse idler shaft 141 is rotatably supported by the first case 11 via a bearing 144 . A rear end of the reverse idler shaft 141 is rotatably supported by the second case 12 via a bearing 145 . In addition, as shown in FIG. 3, the reverse idler shaft 141 is located between the uppermost and lowermost positions of the turbine runner 24 of the torque converter 3 in the vertical direction. facing.

The first reverse gear 142 is formed integrally with the reverse idler shaft 141 . The first reverse gear 142 meshes with the input shaft gear 91 and has a larger gear diameter than the input shaft gear 91 . The second reverse gear 143 is formed integrally with the reverse idler shaft 141 behind the first reverse gear 142 . The second reverse gear 143 meshes with the secondary input gear 121 and has a smaller gear diameter than the secondary input gear 121 .

The output shaft 44 is arranged on the same axis as the input shaft 41 while being spaced rearward from the input shaft 41 . In other words, the input shaft 41 and the output shaft 44 are arranged to have a common axis extending longitudinally along the longitudinal direction of the vehicle with a space therebetween in the longitudinal direction.

A front end of the output shaft 44 is rotatably supported by an adapter 86 via a needle bearing 146 . Almost the entire adapter 86 overlaps the secondary movable sheave 76 and the piston 77 of the secondary pulley 64 in the front-rear direction (overlapping when viewed from the rotational radial direction of the secondary pulley 64). As a result, the output shaft 44 is brought as close as possible to the secondary movable sheave 76 and is arranged to overlap the piston 77 in the longitudinal direction. As a result, the longitudinal length of the transmission unit 1 (CVT 4) is shortened. In addition, the output shaft 44 is rotatably supported by the third case 13 via the bearing 147 with the inner ring of the bearing 147 fitted on the portion spaced rearward from the support portion by the needle bearing 146 . It is

An output shaft gear 148 is integrally formed on the output shaft 44 between a portion supported by the needle bearing 146 and a portion supported by the bearing 147 . Correspondingly, the secondary output gear 149 is spline-fitted and supported on the secondary shaft 62 (second secondary shaft 112) adjacent to the rear side of the piston 77 of the secondary pulley 64 so as to be non-rotatable relative thereto. . The output shaft gear 148 and the secondary output gear 149 mesh with each other, and the output shaft gear 148 has a larger gear diameter than the secondary output gear 149 . The output shaft gear 148 vertically overlaps the piston 77 of the secondary pulley 64 (overlapping when viewed in the front-rear direction).

<Oil supply structure>
FIG. 4 is a diagram showing the configuration inside the second case 12, and is a view of the configuration inside the second case 12 as seen from the rear side. FIG. 5 is a bottom view of a portion of the transmission unit 1 including the second case 12. FIG.

A valve body 151 is provided at the bottom of the second case 12 . Specifically, the valve body 151 is arranged below the secondary pulley 64 at the bottom of the second 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 151 . As shown in FIG. 3, an oil pan 152 is fixed to the second case 12 from below with a plurality of bolts.

A strainer 171 is provided at the bottom of the second case 12 as shown in FIGS. Specifically, at the bottom of the second case 12 , the strainer 171 is arranged below the primary pulley 63 and at the right rear corner portion inside the second case 12 .

Oil is stored in the oil pan 152, and the strainer 171 is immersed in the oil. Due to the rotation of the pump gear 49 of the oil pump 46 , the oil stored in the oil pan 152 is sucked up by the strainer 171 and supplied from the strainer 171 to the valve body 151 . Then, oil is supplied from the valve body 151 as working oil or lubricating oil to each part that requires oil supply.

Hydraulic oil is supplied to the hydraulic chamber 103 of the forward clutch 94 through an oil passage 153 extending upward along the axial radial direction of the primary shaft 61 from a valve body 151 at a position overlapping the oil pump 46 in the longitudinal direction. In the forward clutch 94, the clutch drum 95 is arranged on the oil pump 46 side with respect to the clutch hub 96, and the oil pressure chamber 103 is closer to the oil pump 46 than in the forward clutch 94 that is reversed front to back. . Therefore, in the configuration of the forward clutch 94, the distance from the oil passage 153 to the hydraulic chamber 103 can be shortened, and the length of the oil passage from the oil pump 46 to the hydraulic chamber 103 can be shortened as compared with the configuration in which the configuration is reversed. It is possible to improve the responsiveness by shortening the oil passage length.

Hydraulic oil is supplied to the hydraulic chamber 133 of the reverse clutch 123 through an oil passage 154 extending upward along the axial radial direction of the primary shaft 61 from a valve body 151 at a position overlapping the oil pump 46 in the longitudinal direction. In the reverse clutch 123, the clutch drum 124 is arranged on the oil pump 46 side with respect to the clutch hub 125, and the oil pressure chamber 133 is closer to the oil pump 46 than in the case where the reverse clutch 123 is reversed. . Therefore, in the configuration of the reverse clutch 123, the distance from the oil passage 154 to the hydraulic chamber 133 can be shortened, and the length of the oil passage from the oil pump 46 to the hydraulic chamber 133 can be shortened compared to the configuration in which the configuration is reversed. It is possible to improve the responsiveness by shortening the oil passage length.

A partition wall 155 is formed integrally with the second case 12 as shown in FIG. The partition wall 155 extends along the outer periphery of the primary pulley 63 beyond a position facing the lower end of the primary pulley 63 in the vertical direction toward the secondary pulley 64 to a position facing the left end of the primary pulley 63 in the vertical direction. . The partition wall 155 can isolate the primary pulley 63 from the oil stored in the oil pan 152, and can prevent the lower portion of the primary pulley 63 from being immersed in the oil.

When the vehicle moves forward, the primary pulley 63 rotates clockwise when viewed from the rear side, so even if oil accumulates on the partition wall 155, the accumulated oil is scraped out by the primary pulley 63 to the open end side of the partition wall 155. . As a result, it is possible to prevent the lower portion of the primary pulley 63 from being immersed in oil, reduce the mechanical loss caused by the oil acting as resistance to the rotation of the primary pulley 63, and improve the fuel efficiency of the vehicle.

A primary shaft center oil passage 161 is formed in the second primary shaft 82 of the primary shaft 61 as shown in FIG. The primary shaft center oil passage 161 is open at the rear end face of the second primary shaft 82 . Further, open oil passages 162 and 163 are formed in the second primary shaft 82 so as to be spaced from each other in the axial direction. One end of each of the open oil passages 162 and 163 is connected to the primary axial oil passage 161 , and the open oil passages 162 and 163 communicate with the primary axial oil passage 161 . The other end of open oil passage 162 is open at the outer peripheral surface of second primary shaft 82 . The primary movable sheave 72 is formed with a substantially cylindrical outer fitting portion 164 fitted onto the second primary shaft 82 , and a communication oil passage 165 is formed through the outer fitting portion 164 . . Depending on the position of the primary movable sheave 72, only the open oil passage 162 communicates with the hydraulic chamber 74 of the primary pulley 63, and only the open oil passage 163 communicates with the hydraulic chamber 74 via the communication oil passage 165. Both passages 162 and 163 communicate with hydraulic chamber 74 .

Oil is supplied from the valve body 151 to the primary shaft center oil passage 161 . The oil supplied to the primary shaft center oil passage 161 passes through at least one of the open oil passages 162 and 163 and the communication oil passage 165 in this order and flows into the hydraulic chamber 74. It passes through at least one of oil passage 165 and open oil passages 162 and 163 in this order and flows out to primary shaft center oil passage 161 .

A secondary axial center oil passage 166 is formed in the second secondary shaft 112 of the secondary shaft 62 . The secondary shaft center oil passage 166 is open at the rear end face of the second secondary shaft 112 . An open oil passage 167 is also formed in the second secondary shaft 112 . One end of the open oil passage 167 is connected to the secondary axial oil passage 166 , and the open oil passage 167 communicates with the secondary axial oil passage 166 . The other end of open oil passage 167 is open at the outer peripheral surface of second secondary shaft 112 . The secondary movable sheave 76 is formed with a substantially cylindrical outer fitting portion 168 fitted onto the second secondary shaft 112 , and a communication oil passage 169 is formed through the outer fitting portion 168 . . Regardless of the position of secondary movable sheave 76 , open oil passage 167 communicates with hydraulic chamber 78 of secondary pulley 64 via communication oil passage 169 .

Oil is supplied from the valve body 151 to the secondary shaft center oil passage 166 . The oil supplied to the secondary axial center oil passage 166 passes through the open oil passage 167 and the communicating oil passage 169 in this order and flows into the hydraulic chamber 78. It passes through the oil passages 167 in this order and flows out to the secondary axial center oil passage 166 .

<Strainer>
FIG. 6 is a view of the strainer 171 viewed from the front side.

The strainer 171 integrally includes a body portion 172 and a tube portion 173 extending from the body portion 172 .

The body portion 172 is arranged side by side with the valve body 151 as shown in FIG. The body portion 172 includes a filter chamber 175 containing a filter medium 174 , a discharge port 176 for discharging oil toward the valve body 151 , and a flow path 177 connected to the upper portion of the filter chamber 175 and the discharge port 176 . and are formed. The flow path 177 extends downward from a portion connected to the upper portion of the filtration chamber 175, bends toward the discharge port 176, and bends upward at a position facing the discharge port 176 from below. extends to The discharge port 176 is connected to an oil suction path 178 for sucking the oil discharged from the discharge port 176 into the oil pump 46 . The oil suction path 178 is formed in the second case 12 .

As shown in FIG. 5, the pipe portion 173 extends forward from the lower portion of the filtering chamber 175 of the main body portion 172, and extends under the valve body 151 while curving to the left. It is located in the central part of 12. The pipe portion 173 is formed in a hollow tubular shape, and its interior communicates with the filtering chamber 175 . 5 and 6, a suction port 179 is formed on the lower surface of the tip of the pipe portion 173 to suck the oil stored in the oil pan 152 into the pipe portion 173. As shown in FIGS.

When the oil pump 46 is driven, the oil stored in the oil pan 152 is sucked into the pipe portion 173 through the suction port 179 by the suction force of the oil pump 46 . The oil sucked into the pipe portion 173 flows through the pipe portion 173 toward the main body portion 172, flows into the lower portion of the filtering chamber 175 of the main portion 172, and passes through the filtering medium 174 toward the upper portion of the filtering chamber 175. do. As the oil passes through the filter media 174, foreign matter contained in the oil is captured by the filter media 174 and removed from the oil. The oil that has reached the upper portion of the filtering chamber 175 flows out into the flow path 177 and flows through the flow path 177 toward the discharge port 176 . The oil is discharged from the discharge port 176 , flows through the oil suction passage 178 and is sucked into the oil pump 46 .

A discharge port 181 is formed at the uppermost position of the filter chamber 175 in the body portion 172 . The discharge port 181 is connected to one end of a discharge path 182 formed in the second case 12 . The other end of the discharge path 182 is connected to the oil suction path 178 . The inner cross-sectional area of the discharge path 182 is smaller than the inner cross-sectional area of the oil suction path 178 . Accordingly, when the oil pump 46 is driven, oil is secondarily discharged from the filter chamber 175 to the discharge path 182 through the discharge port 181 .

<Power transmission path>
FIG. 7 is a skeleton diagram showing the power transmission path in the CVT4 together with the configuration of the CVT4.

When the vehicle moves forward, the forward clutch 94 is engaged and the reverse clutch 123 is released. Power input from the engine to the input shaft 41 via the torque converter 3 is transmitted from the input shaft gear 91 to the primary shaft 61 via the primary input gear 92 by engagement of the forward clutch 94 . On the other hand, even if the power input to the input shaft 41 is transmitted from the input shaft gear 91 to the secondary input gear 121 and the secondary input gear 121 rotates, the release of the reverse clutch 123 causes the secondary input gear 121 to rotate to the secondary shaft 62 . (The first secondary shaft 111 ) and power is not transmitted to the secondary shaft 62 .

The power transmitted to the primary shaft 61 is changed at a belt gear ratio according to the pulley ratio between the primary pulley 63 and the secondary pulley 64 and transmitted to the secondary shaft 62 . The power transmitted to the secondary shaft 62 is transmitted from the secondary output gear 149 to the output shaft 44 via the output shaft gear 148, is output from the output shaft 44 to a propeller shaft (not shown), and is output from the propeller shaft. It is transmitted to the left and right rear wheels via the rear differential gear (rear differential) and drive shaft.

Since the gear diameter of primary input gear 92 is larger than that of input shaft gear 91 , the power of input shaft 41 is reduced by input shaft gear 91 and primary input gear 92 and transmitted to primary shaft 61 . In addition, since the gear diameter of the output shaft gear 148 is larger than the gear diameter of the secondary output gear 149, the power of the secondary shaft 62 is reduced by the secondary output gear 149 and the output shaft gear 148 and transmitted to the output shaft 44. . Therefore, when the vehicle moves forward, in the power transmission path from the input shaft 41 to the output shaft 44, the input shaft gear 91 and the primary input gear 92 constitute a primary reduction gear mechanism 201 that reduces power. The secondary output gear 149 constitutes a secondary reduction gear mechanism 202 that further reduces the power.

For example, a configuration in which the secondary shaft 62 is directly connected to the output shaft 44 and the secondary reduction gear mechanism 202 is omitted is conceivable. In this configuration, in order to obtain a reduction ratio by the primary reduction gear mechanism 201 and the secondary reduction gear mechanism 202, the reduction ratio of the primary reduction gear mechanism 201 must be increased, and the gear diameter of the primary input gear 92 must be increased. There is a need to. As the diameter of the primary input gear 92 increases, the size of the CVT 4 increases. Therefore, in the configuration including the secondary reduction gear mechanism 202 in addition to the primary reduction gear mechanism 201, the size of the CVT 4 can be reduced compared to the configuration in which the secondary reduction gear mechanism 202 is omitted.

Further, by providing the primary reduction gear mechanism 201 and the secondary reduction gear mechanism 202, even if the specifications of the engine are changed, the primary reduction gear mechanism 201 can be changed without changing the secondary reduction gear mechanism 202. By changing the design of at least one of the input shaft gear 91 and the primary input gear 92, the CVT 4 can be adapted to the changed specifications of the engine.

When the vehicle moves backward, the forward clutch 94 is released and the reverse clutch 123 is engaged. Power input from the engine to the input shaft 41 via the torque converter 3 is transmitted from the input shaft gear 91 to the secondary shaft 62 via the reverse transmission mechanism 43 and the secondary input gear 121 due to engagement of the reverse clutch 123 . . At this time, the secondary shaft 62 rotates in a direction opposite to that during forward movement of the vehicle. On the other hand, even if the power input to the input shaft 41 is transmitted from the input shaft gear 91 to the primary input gear 92 and the primary input gear 92 rotates, the forward clutch 94 is released and the primary input gear 92 rotates to the primary shaft 61 . (The first primary shaft 81 ) and power is not transmitted to the primary shaft 61 .

The power transmitted to the secondary shaft 62 is transmitted from the secondary output gear 149 to the output shaft 44 via the output shaft gear 148, is output from the output shaft 44 to the propeller shaft, and is transmitted from the propeller shaft to the rear differential gear and the drive shaft. It is transmitted to the left and right rear wheels via the

The gear diameter of the first reverse gear 142 of the reverse transmission mechanism 43 is larger than the gear diameter of the input shaft gear 91, and the gear diameter of the secondary input gear 121 is larger than the gear diameter of the second reverse gear 143 of the reverse transmission mechanism 43. , the power of the input shaft 41 is reduced by the input shaft gear 91 , the reverse transmission mechanism 43 and the secondary input gear 121 and transmitted to the secondary shaft 62 . In addition, since the gear diameter of the output shaft gear 148 is larger than the gear diameter of the secondary output gear 149, the power of the secondary shaft 62 is reduced by the secondary output gear 149 and the output shaft gear 148 and transmitted to the output shaft 44. . Therefore, when the vehicle moves backward, in the power transmission path from the input shaft 41 to the output shaft 44, the input shaft gear 91, the reverse transmission mechanism 43, and the secondary input gear 121 constitute a primary reduction gear mechanism 203 that reduces power. The output shaft gear 148 and the secondary output gear 149 constitute a secondary reduction gear mechanism 202 that further reduces the power.

<Effect>
As described above, the strainer 171 has the body portion 172 in which the filtering material 174 is accommodated, and the tube portion 173 in which the suction port 179 is formed. Since the filter material 174 is not accommodated in the pipe portion 173 , the pipe portion 173 can be formed thinner than the main body portion 172 . Therefore, the main body portion 172 is arranged side by side with the valve body 151, and the pipe portion 173 extends from the main body portion 172 and extends below the valve body 151, so that the entire strainer is arranged below the valve body 151. Compared to the configuration, the vertical size of the transmission unit 1 (CVT 4) can be reduced. In addition, since the suction port 179 is formed at a position facing the central portion of the oil pan 152, the oil accumulates in the oil pan 152 regardless of the behavior of the vehicle in which the transmission unit 1 is mounted, such as turning, starting, or stopping. The oil can be well sucked into the strainer 171 (inside the pipe portion 173) from the suction port 179.

In addition, in the CVT 4 , a primary shaft 61 and a secondary shaft 62 are arranged separately on the left and right with respect to the input shaft 41 . The primary shaft 61 and the secondary shaft 62 are offset to one side and the other side in the vertical direction, respectively, with respect to the input shaft 41 . Specifically, in the CVT 4 , the primary shaft 61 is arranged below the input shaft 41 and the secondary shaft 62 is arranged above the input shaft 41 . Thereby, the distance between the primary shaft 61 and the secondary shaft 62 in the vertical direction can be shortened. As a result, the vertical size of the transmission unit 1 can be further reduced.

A valve body 151 having a relatively large vertical size is disposed below the secondary pulley 64 (secondary shaft 62) positioned relatively high, and the primary pulley positioned relatively low. A strainer 171 having a relatively small size in the vertical direction is arranged below 63 (primary shaft 61). With this layout, it is possible to further reduce the size of the transmission unit 1 in the vertical direction.

As a result, even in a vehicle such as a commercial vehicle having a low-floor cabin, it is possible to mount the transmission unit 1 on the vehicle while ensuring the minimum ground clearance of the vehicle.

<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 gear diameter of the first reverse gear 142 of the reverse transmission mechanism 43 is larger than the gear diameter of the input shaft gear 91, but depending on the size (output) of the engine combined with the CVT 4, the The gear diameter of the 1 reverse gear 142 may be made smaller than the gear diameter of the input shaft gear 91 .

Moreover, although the CVT 4 for vertical installation has been taken up as an example of the transmission, the present invention can also be applied to a transmission that is installed horizontally so that the input shaft extends in the left-right direction of the vehicle.

The power transmission method of the continuously variable transmission mechanism 42 is not limited to the belt type, and may be a chain type or a toroidal type. Further, the transmission mechanism provided in the transmission unit 1 is not limited to the continuously variable transmission mechanism 42, and may be a stepped transmission mechanism.

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

1: Transmission unit (transmission)
4: CVT (transmission)
41: Input shaft 42: Continuously variable transmission mechanism (transmission mechanism)
44: Output shaft 151: Valve body 152: Oil pan 171: Strainer 172: Body part 173: Pipe part 174: Filter material 179: Suction port

Claims (1)

a case forming an outer shell;
a speed change mechanism that is supported by the case and that shifts power input to the input shaft and transmits it to the output shaft;
a valve body that supplies oil to the transmission mechanism;
an oil pan that is attached to the case from below the valve body and stores oil;
a strainer that sucks oil accumulated in the oil pan from a suction port and supplies the oil to the valve body through a filtering material;
The valve body is arranged below the speed change mechanism,
The strainer has a body portion in which the filtering material is accommodated, and a pipe portion through which the oil sucked from the suction port flows toward the body portion,
The main body includes a filtering chamber in which the filtering medium is accommodated, a discharge port for discharging oil from the bottom to the top toward the valve body, and a flow path connected to the filtering chamber and the discharge port. with
a portion of the body portion where the filtration chamber is formed is arranged side by side with the valve body,
the pipe portion extends from the main body portion and extends below the valve body;
The suction port is formed in the pipe portion and faces a central portion of the oil pan ,
The transmission, wherein the flow path extends downward from a portion connected to an upper portion of the filtering chamber, bends toward the discharge port, and extends to the discharge port.

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