JP7391464B2 - transmission - Google Patents

Description

The present invention relates to a transmission.

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

2. Description of the Related Art Vertical CVTs (Continuously Variable Transmissions) have already been provided as transmissions for vehicles in which engines are mounted vertically. A vertical CVT is arranged such that an input shaft to which engine power is input is oriented vertically with respect to the longitudinal direction of the vehicle body. In an example of a vertical CVT, the input shaft and the output shaft that outputs power to the propeller shaft are arranged on the same axis, and between the input shaft and the output shaft, the primary shaft is arranged on the same axis as the input shaft and the output shaft. (For example, see Patent Document 1). The input shaft and the primary shaft are connected to be able to transmit power, and power input from the engine to the input shaft is transmitted from the input shaft to the primary shaft. A secondary shaft is arranged in parallel with the primary shaft with an interval therebetween, and an endless belt is wound between the primary pulley supported by the primary shaft and the secondary pulley supported by the secondary shaft. Thereby, the power transmitted from the input shaft to the primary shaft is transmitted from the primary pulley to the belt, and from the belt to the secondary pulley. In addition, an intermediate shaft is provided that extends parallel to the secondary shaft with a space between them, and the power transmitted to the secondary pulley is transmitted from the secondary shaft to the intermediate shaft via a gear, and from the intermediate shaft to the output shaft. transmitted through.

Japanese Patent Application Publication No. 2012-192855

However, during the process of developing a new vehicle with an FR layout in which the engine is mounted vertically, it was discovered that the conventional vertical CVT structure could not be used in the new vehicle.

An object of the present invention is to provide a transmission with a new structure that is different from a conventional vertical CVT.

In order to achieve the above object, the transmission according to the present invention includes an input shaft into which power from a drive source is input, an output shaft extending parallel to the input shaft, and a power transmission between the input shaft and the output shaft. A continuously variable transmission mechanism that has a primary shaft and a secondary shaft that are provided on the path and extend parallel to the input shaft, respectively, and that transmits power from the primary shaft to the secondary shaft by changing the speed, the primary shaft and the secondary shaft are When viewed from the axial direction of the input shaft, they are arranged on the left and right sides of the input shaft.

According to this configuration, with respect to the input shaft, the primary shaft and the secondary shaft are arranged separately on the left and right sides 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 reduced, and even in vehicles with low-floor cabins such as commercial vehicles, it is possible to install the transmission in the vehicle by reducing the minimum ground clearance of the vehicle. It can be made possible while ensuring that

Further, by downsizing the transmission, it is possible to reduce the weight of the transmission, and as a result, it is possible to improve the fuel efficiency of the vehicle in which the transmission is mounted. Furthermore, it is possible to reduce costs by downsizing the transmission.

The input shaft may be arranged to extend in the longitudinal direction of the vehicle in which the transmission is mounted. That is, the transmission may be mounted on the vehicle vertically, with the input shaft oriented vertically with respect to the longitudinal direction of the vehicle.

The primary axis and the secondary axis may be offset to one side and the other side in the vertical direction with respect to the input axis, respectively. For example, the primary shaft may be located below the input shaft, and the secondary shaft may be located above the input shaft. As a result, a space can be provided above the primary shaft in the engine compartment, and a starter for starting the engine can be placed in that space.

If a configuration is further adopted in which a primary shaft and a secondary shaft support a primary pulley and a secondary pulley, respectively, and an endless belt is wound around the primary pulley and secondary pulley, the primary shaft located below the secondary shaft Preferably, a partition wall is provided below to prevent the primary pulley from being immersed in oil. Thereby, it is possible to reduce mechanical losses caused by the oil in the transmission acting as resistance to rotation of the primary pulley, and it is possible to improve fuel efficiency of a vehicle in which the transmission is mounted.

The transmission may include a mechanical oil pump driven by the power of the input shaft, and the oil pump is provided on the axis of the input shaft and disposed between the primary shaft and the secondary shaft. You can leave it there. By making good use of the space between the primary shaft and the secondary shaft and arranging the oil pump, the size of the transmission, especially the size of the input shaft in the axial direction, can be reduced.

According to the present invention, it is possible to provide a transmission with a new structure that is different from a conventional vertical CVT. It is possible to mount a transmission on a vehicle while ensuring the minimum ground clearance of the vehicle.

FIG. 1 is a sectional view showing the configuration of a transmission unit according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing a part of the transmission unit extracted from FIG. 1 and shown in an enlarged manner. FIG. 3 is a diagram of the inside of the second case of the transmission unit viewed from the rear side (the side opposite to the engine side). FIG. 2 is a skeleton diagram showing the configuration of a vertical CVT and a power transmission path in the vertical CVT.

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

<Transmission unit>
FIG. 1 is a sectional view showing the configuration of a transmission unit 1 according to an embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view of a part of the transmission unit 1 extracted from FIG. 1. As shown in FIG. Note that in the cross-sectional views shown in FIG. 1 and subsequent figures, hatching representing the cross-section is omitted.

The transmission unit 1 is a unit that is mounted on a vehicle and changes the speed of power generated by an engine (not shown) as a drive source for driving. The vehicle adopts an FR layout, and the engine is mounted vertically with the crankshaft oriented vertically with respect to the longitudinal direction of the vehicle body. The transmission unit 1 includes a torque converter 3 and a vertical CVT 4 inside a unit case 2 that forms an outer shell.

<Unit case>
The unit case 2 is composed of 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 a die-casting method. 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 being fastened with bolts 14. The torque converter 3 is housed in a first case 11, and the vertical CVT 4 is housed in a second case 12 and a third case 13.

<Torque converter>
The torque converter 3 includes a front cover 21, a pump impeller 22, a turbine hub 23, a turbine runner 24, a lockup mechanism 25, and a stator 26.

The front cover 21 extends in a substantially disk shape around a rotational axis extending in the longitudinal direction of the vehicle (vehicle body), and its outer peripheral end is on the rear side, which is the side opposite to the engine side (the side of the continuously variable transmission mechanism 42 described later). It has a curved shape. The center of the front cover 21 bulges forward. The crankshaft of the engine is coupled to this bulged portion in a relatively non-rotatable manner.

The pump impeller 22 is arranged on the vertically placed CVT 4 side of the front cover 21. The outer circumferential end of the pump impeller 22 is connected to the outer circumferential end of the front cover 21, and is provided so as to be rotatable together with the front cover 21 about the rotation axis. A plurality of blades 27 are arranged radially on the inner surface of the pump impeller 22 .

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

Turbine runner 24 is fixed to turbine hub 23. A plurality of blades 28 are arranged radially on the surface of the turbine runner 24 facing the pump impeller 22 .

The lockup mechanism 25 includes a lockup piston 31 and a damper mechanism 32.

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

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

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

When the pump impeller 22 rotates due to engine torque in the lock-up off state, oil flows from the pump impeller 22 toward the turbine runner 24. This oil flow is received by the blades 28 of the turbine runner 24, causing the turbine runner 24 to rotate. At this time, the amplification effect of the torque converter 3 occurs, and a torque larger than the engine torque is generated in the turbine runner 24.

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

Input shaft 41 is formed into a hollow shaft and extends on the rotation axis of torque converter 3 . The front end of the input shaft 41 is inserted into the torque converter 3 and spline-fitted to the turbine hub 23 .

A central portion of the input shaft 41 in the axial direction 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 (on the side opposite to the engine side). The oil pump 46 includes a pump case 47 and a pump cover 48 that is overlapped with the pump case 47. Pump case 47 and pump cover 48 are fastened together with a plurality of bolts and held in second case 12. A pump gear 49 is housed in a space surrounded by the pump case 47 and the pump cover 48.

The pump case 47 is arranged on the front side with respect to the pump cover 48. As shown in FIG. 2, a circular recess 51 that is recessed toward the rear is formed at the front end of the pump case 47. The 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.

As shown in FIG. 1, one end of a pump shaft 54 is connected to the pump gear 49 so as to be relatively non-rotatable. The pump shaft 54 passes through the center of the recess 51, projects forward from the pump case 47, and is inserted into the hollow portion of the input shaft 41 with a gap between it and the inner peripheral surface of the input shaft 41. The front end of the pump shaft 54 is inserted into the central portion of the front cover 21 of the torque converter 3 that bulges out to the front, and is coupled to the front cover 21 in a relatively non-rotatable manner. As a result, when the front cover 21 is rotated by the power of the engine, the pump shaft 54 and the pump gear 49 rotate together with the front cover 21, and oil pressure is generated from the oil pump 46.

Further, the input shaft 41 is rotatably supported by the first case 11 via a bearing 45, rotatably supported by the pump case 47 via a needle bearing 52 and a thrust bearing 53, and is rotatably supported by the turbine hub of the torque converter 3. Due to the spline fitting with 23, when the turbine runner 24 rotates, it rotates together with the turbine runner 24.

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

FIG. 3 is a diagram of the inside of the second case 12 viewed from the rear side. Note that FIG. 1 is a cross-sectional view of the transmission unit 1 taken along the cutting line AA shown in FIG.

The primary shaft 61 extends parallel to the input shaft 41 with its axial center spaced apart to the lower right when viewed from the rear side of the vehicle with respect to the axial center of the input shaft 41 . The distance between the axes of the input shaft 41 and the primary shaft 61, in other words, the distance in the shaft radial direction (rotational radial direction) between the axis of the input shaft 41 and the axis of the primary shaft 61 is the distance between the axes of the input shaft 41 and the primary shaft 61. It is shorter than the turning radius of 24.

The secondary shaft 62 extends parallel to the input shaft 41 with its axial center spaced apart to the upper left when viewed from the rear of the vehicle with respect to the axial center of the input shaft 41 . The distance between the axes of the input shaft 41 and the secondary shaft 62, in other words, the distance in the shaft radial direction 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. It is equal to the distance in the shaft radial direction between the radial direction and the radius of rotation of the turbine runner 24 of the torque converter 3.

Therefore, when viewed in the longitudinal direction of the vehicle, the axial center of the primary shaft 61 and the axial center of the secondary shaft 62 are point symmetrical about the axial center of the input shaft 41. Further, the primary shaft 61 and the secondary shaft 62 have their vertical positions between the uppermost position and the lowermost position of the turbine runner 24 of the torque converter 3, and are opposed to the turbine runner 24 in the longitudinal direction. There is.

As shown in FIG. 1, the primary pulley 63 is arranged to face a primary fixed sheave 71 fixed to the primary shaft 61 and a belt 65 between the primary fixed sheave 71, and is movable in the axial direction of the primary shaft 61. and a primary movable sheave 72 supported so as not to be relatively rotatable. 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 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 from the primary shaft 61 in the shaft radial direction, and an outer peripheral end bent rearward. The outer peripheral end of the primary movable sheave 72 is in fluid-tight contact with the outer peripheral end of the cylinder 73 from inside in the rotational radial direction. A piston chamber (hydraulic chamber) 74 is formed between the primary movable sheave 72 and the cylinder 73.

The secondary pulley 64 is arranged to face a 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 to rotate relative to the secondary shaft 62. A secondary movable sheave 76 is provided. The secondary movable sheave 76 is disposed 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 such that the primary fixed sheave 71 of the primary pulley 63 and the primary 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 from the secondary shaft 62 in the shaft radial direction. The outer peripheral end of the secondary movable sheave 76 extends rearward, and the outer peripheral end of the piston 77 fluid-tightly contacts the outer peripheral end of the secondary movable sheave 76 from inside in the rotational radial direction. A piston chamber (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 vertically overlap with a portion of the primary movable sheave 72 and the cylinder 73 (overlapping 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 its front end is bent outward in the rotational radial direction, and the secondary fixed sheave 75 extends at the outer peripheral end of the primary movable sheave 72. It faces a portion extending in the front-rear direction from the outside in the rotational radial direction, and faces a portion extending in the rotational radial direction at the outer peripheral end from the rear side.

In the continuously variable transmission mechanism 42, the hydraulic pressure supplied to the piston chambers 74, 78 of the primary pulley 63 and the secondary pulley 64 is controlled, and the groove widths of the primary pulley 63 and the secondary pulley 64 are changed, thereby changing the speed. The ratio (the pulley ratio between the primary pulley 63 and the secondary pulley 64) is continuously and steplessly changed.

Specifically, when the gear ratio is decreased, the oil pressure supplied to the piston 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 interval (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 gear ratio becomes smaller.

When the gear ratio is increased, the oil pressure supplied to the piston chamber 74 of the primary pulley 63 is lowered. As a result, the thrust force of the secondary pulley 64 with respect to the belt 65 becomes larger than the thrust force of the primary pulley 63 with respect to 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 and the primary movable sheave 72 becomes larger. As a result, the gear ratio increases.

A bias spring 69 is provided in the piston chamber 68 of the secondary pulley 64. The bias spring 69 has one end in elastic contact with the secondary movable sheave 76 and the other end in elastic contact with the piston 77. The elastic force of the bias spring 69 urges the secondary movable sheave 76 and the piston 77 in a direction away from each other. A biasing force is applied to the secondary movable sheave 76 by the hydraulic pressure in the piston chamber 68 and a bias spring 69, and a corresponding pinching pressure is applied to the belt 65.

Further, the primary shaft 61 is configured to be 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. The primary pulley 63 is supported by the 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 within the connection recess 83 , the outer peripheral surface of the second primary shaft 82 is spline-fitted with the inner peripheral surface of the connection recess 83 . . The front end 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 held by the second case 12 is arranged on the rear side of the primary pulley 63, and the rear end of the second primary shaft 82 is rotatably supported by the adapter 86 via a bearing 87. has been done.

As shown in FIG. 2, an input shaft gear 91 is integrally formed on the input shaft 41 at a portion adjacent to the rear side of a portion into which the inner race of the bearing 45 is fitted. Correspondingly, a primary input gear 92 is supported by the first primary shaft 81 via a needle bearing 93 so as to be relatively rotatable. 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 allows/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). The forward clutch 94 includes a clutch drum 95, a clutch hub 96, a clutch piston 97, and a canceller 98.

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

Clutch hub 96 is integrally formed 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 circumferential end of the clutch drum 95 from the inner side in the rotational radial direction at a distance. A plurality of clutch disks 102 are held on the clutch hub 96 at intervals in the front-rear direction. Clutch plates 101 and 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 front-back direction. The clutch piston 97 extends from the first primary shaft 81 to the outside in the radial direction of the first primary shaft 81, and has an outer peripheral end bent forward. The tip of the outer peripheral end of the clutch piston 97 contacts the clutch plate 101 . Further, the clutch piston 97 is in fluid-tight contact with the clutch drum 95, and a piston chamber 103 is formed between the clutch drum 95 and the clutch piston 97 to which hydraulic pressure acting on the clutch piston 97 is supplied. ing.

A canceller 98 is provided between the clutch hub 96 and the clutch piston 97. An inner peripheral end of the canceller 98 is fixed to the first primary shaft 81. The 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 urged in a direction away from each other by the urging force of the return spring 105.

Clutch piston 97 moves toward clutch plate 101 by hydraulic pressure supplied to piston chamber 103 and presses clutch plate 101 . This pressure brings the clutch plate 101 and clutch disc 102 into pressure contact, and the forward clutch 94 is engaged. By engaging the forward clutch 94, rotation of the primary input gear 92 with respect to the first primary shaft 81 is prohibited, 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 clutch piston 97 is separated from the clutch plate 101 due to the urging force of the return spring 105 interposed between the clutch piston 97 and the canceller 98. As a result, the pressure contact between clutch disc 102 and clutch plate 101 is released, and forward clutch 94 is released. By releasing the forward clutch 94, rotation of the primary input gear 92 with respect to the first primary shaft 81 is allowed, 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 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 within the connection recess 113, the outer peripheral surface of the second secondary shaft 112 is spline-fitted with the inner peripheral surface of 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 it with the first primary shaft 81. By using the first primary shaft 81 and the first secondary shaft 111 in common, the number of types of parts that make up the transmission unit 1 (vertical CVT 4) can be reduced, and the manufacturing cost of the transmission unit 1 can be reduced. . A front end 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 of the second secondary shaft 112 is rotatably supported by the third case 13 via a bearing 116.

A secondary input gear 121 is supported by the second secondary shaft 112 on the rear side of the bearing 114 via a needle bearing 122 so as to be relatively rotatable.

A reverse clutch 123 is provided that utilizes the space between the secondary input gear 121 and the pump case 47 of the oil pump 46 to allow/prohibit rotation of the secondary input gear 121 with respect to the first secondary shaft 111. A portion of the reverse clutch 123 overlaps with the oil pump 46 in the rotational radial direction (overlapping when viewed in the rotational axis direction). The reverse clutch 123 includes 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 from the first secondary shaft 111 in the shaft radial direction, and an outer peripheral end bent and extends toward the secondary input gear 121 side, that is, toward the front side. A plurality of clutch plates 131 are held at the outer peripheral end of the clutch drum 124 in a row at intervals in the front-rear direction.

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 of the clutch drum 124 from the inner side in the rotational radial direction with a space therebetween. A plurality of clutch disks 132 are held by the clutch hub 125 at intervals in the front-rear direction. Clutch plates 131 and clutch discs 132 are arranged alternately in the central axis direction. The number of clutch plates 131 and clutch discs 132 is greater than the number of clutch plates 101 and clutch discs 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 front-back direction. The clutch piston 126 extends from the first secondary shaft 111 to the outside in the radial direction of the first secondary shaft 111, and has an outer peripheral end bent forward. The tip of the outer peripheral end of the clutch piston 126 contacts the clutch plate 131 . Further, the clutch piston 126 is in liquid-tight contact with the clutch drum 124, and a piston chamber 133 is formed between the clutch drum 124 and the clutch piston 126 to which hydraulic pressure acting on the clutch piston 126 is supplied. 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. The outer peripheral end of the canceller 127 is in liquid-tight contact with the clutch piston 126. As a result, 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 urged in a direction away from each other by the urging force of the return spring 135.

Clutch piston 126 moves toward clutch plate 131 by hydraulic pressure supplied to piston chamber 133 and presses clutch plate 131 . This pressure brings the clutch plate 131 and clutch disc 132 into pressure contact, and the reverse clutch 123 is engaged. By engaging the reverse clutch 123, rotation of the secondary input gear 121 with respect to the first secondary shaft 111 is prohibited, and when the secondary input gear 121 rotates, the first secondary shaft 111 rotates together with the secondary input gear 121. When the hydraulic pressure is released from the engaged state of the reverse clutch 123, the clutch piston 126 is separated from the clutch plate 131 due to the urging force of the return spring 135 interposed between the clutch piston 126 and the canceller 127. As a result, the pressure contact between clutch disc 132 and clutch plate 131 is released, and reverse clutch 123 is released. By releasing the reverse clutch 123, rotation of the secondary input gear 121 with respect to the first secondary shaft 111 is allowed, and even if the secondary input gear 121 rotates, the rotation is not transmitted to the first secondary shaft 111.

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 shaft 141, a first reverse gear 142, and a second reverse gear 143.

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

The first reverse gear 142 is formed integrally with the reverse 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 shaft 141 on the rear side of 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 disposed on the same axis as the input shaft 41 with a space behind the input shaft 41 . In other words, the input shaft 41 and the output shaft 44 are arranged at intervals in the front-rear direction, respectively, so as to have a common axis extending vertically along the front-rear direction of the vehicle.

A front end of the output shaft 44 is rotatably supported by an adapter 86 via a needle bearing 146. The adapter 86 substantially entirely overlaps the secondary movable sheave 76 and the piston 77 of the secondary pulley 64 in the front-rear direction (overlaps when viewed from the rotational radial direction of the secondary pulley 64). As a result, the output shaft 44 is brought almost as close as possible to the secondary movable sheave 76 and is arranged to overlap the piston 77 in the front-rear direction. Thereby, the longitudinal length of the transmission unit 1 (vertical CVT 4) is shortened. Further, the output shaft 44 is rotatably supported by the third case 13 via the bearing 147, with an inner ring of a bearing 147 being fitted onto a portion spaced rearward from the portion supported by the needle bearing 146. has been done.

An output shaft gear 148 is integrally formed on the output shaft 44 between a portion supported by a needle bearing 146 and a portion supported by a bearing 147. Correspondingly, a secondary output gear 149 is supported on the secondary shaft 62 (second secondary shaft 112) so as to be relatively non-rotatable by spline fitting adjacent to the rear side of the piston 77 of the secondary pulley 64. . 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 overlaps the piston 77 of the secondary pulley 64 in the vertical direction (overlapping when viewed in the front-rear direction).

<Valve body>
A valve body 151 is provided 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. An oil pan 152 is fixed to the second case 12 from below with a plurality of bolts. Oil is stored in the oil pan 152, and a strainer is immersed in the oil. As the pump gear 49 of the oil pump 46 rotates, oil stored in the oil pan 152 is sucked up through the strainer and supplied to the valve body 151. Then, oil is supplied as hydraulic oil or lubricating oil from the valve body 151 to each part that requires oil supply.

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

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

Furthermore, a partition wall 155 is formed in the second case 12, as shown in FIG. The partition wall 155 extends along the outer periphery of the primary pulley 63 from a position vertically facing the lower end of the primary pulley 63 to a position vertically facing the left end of the primary pulley 63 and beyond the secondary pulley 64 side. It bends and extends to the lower left at the position. The partition wall 155 can isolate the primary pulley 63 from the oil stored in the oil pan 152, and can prevent the lower part of the primary pulley 63 from being immersed in the oil. Furthermore, when the vehicle moves forward, the primary pulley 63 rotates clockwise when viewed from the rear, so even if oil accumulates on the bulkhead 155, the primary pulley 63 scrapes the accumulated oil toward the open end of the bulkhead 155. Served. As a result, it is possible to suppress the lower part of the primary pulley 63 from being immersed in oil, reduce mechanical losses caused by oil acting as resistance to rotation of the primary pulley 63, and improve fuel efficiency of the vehicle.

<Power transmission path>
FIG. 4 is a skeleton diagram showing the configuration of the vertically installed CVT 4 and a power transmission path in the vertically installed CVT 4. As shown in FIG.

When the vehicle moves forward, forward clutch 94 is engaged and reverse clutch 123 is released. Power input from the engine to input shaft 41 via torque converter 3 is transmitted from input shaft gear 91 to primary shaft 61 via primary input gear 92 through engagement of 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) rotates idly, and no power is transmitted to the secondary shaft 62.

The power transmitted to the primary shaft 61 is transmitted to the secondary shaft 62 after being changed in speed according to the pulley ratio of the primary pulley 63 and the secondary pulley 64. 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 transmitted from the propeller shaft to the output shaft 44. 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 the gear diameter of input shaft gear 91, the power of input shaft 41 is reduced in speed by input shaft gear 91 and primary input gear 92, and then transmitted to primary shaft 61. Further, 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 shaft gear 149 and the output shaft gear 148, and is transmitted to the output shaft 44. . Therefore, when the vehicle moves forward, the input shaft gear 91 and the primary input gear 92 constitute a primary reduction gear mechanism 156 that decelerates the power in the power transmission path from the input shaft 41 to the output shaft 44, and the output shaft gear 148 and The secondary shaft gear 149 constitutes a secondary reduction gear mechanism 157 that further reduces the power.

For example, a configuration may be considered in which the secondary shaft 62 is directly connected to the output shaft 44 and the secondary reduction gear mechanism 157 is omitted. In this configuration, in order to obtain the reduction ratio by the primary reduction gear mechanism 156 and the secondary reduction gear mechanism 157, the reduction ratio of the primary reduction gear mechanism 156 must be increased, and the gear diameter of the primary input gear 92 must be increased. There is a need to. By increasing the gear diameter of the primary input gear 92, the size of the vertically installed CVT 4 increases. Therefore, in a configuration that includes the secondary reduction gear mechanism 157 in addition to the primary reduction gear mechanism 156, the vertically installed CVT 4 can be made smaller compared to a configuration in which the secondary reduction gear mechanism 157 is omitted.

Furthermore, by providing the primary reduction gear mechanism 156 and the secondary reduction gear mechanism 157, when the engine specifications are changed, the primary reduction gear mechanism 156 can be changed without changing the secondary reduction gear mechanism 157. By changing the design of at least one of the input shaft gear 91 and the primary input gear 92, the vertical CVT 4 can be adapted to the changed specifications of the engine.

When the vehicle is traveling backwards, forward clutch 94 is released and 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 by engagement of the reverse clutch 123. . At this time, the secondary shaft 62 rotates in the opposite direction to when the vehicle moves forward. On the other hand, even if the power input to the input shaft 41 is transmitted from the input shaft gear 91 to the primary input gear 92 and the primary input gear 92 rotates, the release of the forward clutch 94 causes the primary input gear 92 to move toward the primary shaft 61. (first primary shaft 81) and no power is 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, and is output from the output shaft 44 to the propeller shaft, and is transmitted from the propeller shaft to the rear differential gear and drive shaft. is transmitted to the left and right rear wheels.

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 in speed by the input shaft gear 91, the reverse transmission mechanism 43, and the secondary input gear 121, and is transmitted to the secondary shaft 62. Further, 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 shaft gear 149 and the output shaft gear 148, and is transmitted to the output shaft 44. . Therefore, when the vehicle is traveling backwards, the input shaft gear 91, reverse transmission mechanism 43, and secondary input gear 121 constitute a primary reduction gear mechanism 158 that decelerates the power in the power transmission path from the input shaft 41 to the output shaft 44, Output shaft gear 148 and secondary shaft gear 149 constitute a secondary reduction gear mechanism 157 that further decelerates the power.

<Effect>
As described above, the primary shaft 61 and the secondary shaft 62 are arranged on the left and right sides of 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 vertically installed CVT 4 can be reduced in the vertical direction. In the transmission unit 1, the vertical size of the continuously variable transmission mechanism 42 is reduced to such an extent that the vertical positions of the primary shaft 61 and the secondary shaft 62 fall between the uppermost position and the lowermost position of the torque converter 3. ing. Therefore, even if the vehicle has a low-floor cabin such as a commercial vehicle, the transmission unit 1 can be mounted on the vehicle while ensuring the minimum ground clearance of the vehicle.

The primary shaft 61 and the secondary shaft 62 are offset from the input shaft 41 to one side and the other side in the vertical direction, respectively. Specifically, in the vertical CVT 4, the primary shaft 61 is arranged at a position below the input shaft 41, and the secondary shaft 62 is arranged at a position above the input shaft 41. As a result, a space can be provided above the primary shaft 61 in the engine compartment in which the transmission unit 1 is housed, and a starter 161 for starting the engine can be placed in this space.

The vertical CVT 4 includes a mechanical oil pump 46 driven by the power of the input shaft 41 . The oil pump 46 is provided on the axis of the input shaft 41 and is disposed between the primary shaft 61 and the secondary shaft 62. By arranging the oil pump 46 while making good use of the space between the primary shaft 61 and the secondary shaft 62, the size of the vertical CVT 4, particularly in the longitudinal direction, can be reduced.

In addition, in the vertical CVT 4, when the vehicle moves forward, power is transmitted from the input shaft 41 to the primary shaft 61, the power is transmitted from the primary shaft 61 to the secondary shaft 62 with a changed speed, and further from the secondary shaft 62 to the output shaft 44. transmitted to. Therefore, when the vehicle moves forward, power can be transmitted from the input shaft 41 to the output shaft 44 while changing the speed.

On the other hand, when the vehicle is traveling backwards, power is transmitted from the input shaft 41 to the secondary shaft 62, and from the secondary shaft 62 to the output shaft 44. Therefore, when the vehicle is traveling backwards, power can be transmitted from the input shaft 41 to the output shaft 44 without passing through the continuously variable transmission mechanism 42. Since the power does not pass through the continuously variable transmission mechanism 42, the power transmission efficiency is improved, so that the fuel efficiency of the vehicle in which the vertically installed CVT 4 is mounted can be improved. Furthermore, since hydraulic pressure is not required to control the speed change by the continuously variable transmission mechanism 42, it is possible to obtain the effect of improving fuel efficiency by eliminating the need for the hydraulic pressure. Furthermore, when operating the accelerator, a direct (linear) driving feeling can be obtained. Furthermore, even if an overload is input to the vehicle from the road surface, the continuously variable transmission mechanism 42 can be protected from the overload.

Furthermore, since a planetary gear mechanism for switching between forward and reverse movement of the vehicle is not required, the vertical CVT 4 can be downsized.

The primary movable sheave 72 of the primary pulley 63 and the secondary movable sheave 76 of the secondary pulley 64 are arranged on opposite sides of the belt 65. Thereby, the primary movable sheave 72 and the secondary movable sheave 76 can apply clamping pressure to the belt 65 from both sides thereof, and the occurrence of slippage of the belt 65 can be suppressed.

In the secondary pulley 64, the outer circumferential end of the piston 77 liquid-tightly contacts the outer circumferential end of the secondary movable sheave 76 from the inside in the rotational radial direction. Therefore, the size of the secondary movable sheave 76 in the longitudinal direction is larger than the size of the primary movable sheave 72 in the longitudinal direction. Therefore, in a configuration in which the primary movable sheave 72 is disposed on the rear side (on the side opposite to the engine side) with respect to the primary fixed sheave 71, and the secondary movable sheave 76 is disposed on the front side (on the engine side) with respect to the secondary fixed sheave 75, , compared to a configuration in which the primary movable sheave 72 is disposed on the front side with respect to the primary fixed sheave 71 and the secondary movable sheave 76 is disposed on the rear side with respect to the secondary fixed sheave 75, the position of the belt 65 in the axial direction is rearward. 2, and the continuously variable transmission mechanism 42 including the primary pulley 63, secondary pulley 64, and belt 65 becomes longer in the longitudinal direction.

Therefore, with the configuration in which the primary movable sheave 72 is disposed on the front side with respect to the primary fixed sheave 71 and the secondary movable sheave 76 is disposed on the rear side with respect to the secondary fixed sheave 75, the length of the continuously variable transmission mechanism 42 in the longitudinal direction is reduced. It is possible to reduce the length of time. Then, by arranging other members such as the output shaft 44 in the space created by this and overlapping the other members in the radial direction of the secondary pulley 64 and the input shaft 41, while keeping the length in the axial direction short, The size in the radial direction of the shaft can also be reduced.

Furthermore, by partially overlapping the oil pump 46 with the forward clutch 94 and the reverse clutch 123 in the radial direction of the input shaft 41, the size of the vertically installed CVT 4 in the radial direction is reduced.

Therefore, it is possible to reduce the size of the vertically installed CVT 4, and even in a vehicle with a low-floor cabin such as a commercial vehicle, it is possible to install the transmission unit 1 including the vertically installed CVT 4 in the vehicle. This can be done while ensuring ground clearance.

Further, by downsizing the vertical CVT 4, it is possible to reduce the weight of the transmission unit 1, and as a result, it is possible to improve the fuel efficiency of the vehicle in which the transmission unit 1 is mounted. Furthermore, it is possible to reduce costs by downsizing the transmission unit 1.

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

For example, in the above 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 vertical CVT 4, , the gear diameter of the first reverse gear 142 may be made smaller than the gear diameter of the input shaft gear 91.

Further, although a vertically installed CVT4 was taken up as an example of a transmission, the present invention is not limited to a vertically installed CVT4, but 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 a belt type, but may be a chain type or a toroidal type.

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

4: Vertical CVT (transmission)
41: Input shaft 42: Continuously variable transmission mechanism 61: Primary shaft 62: Secondary shaft

Claims (1)

an input shaft into which power from the drive source is input;
an output shaft extending parallel to the input shaft;
A primary shaft and a secondary shaft are provided on a power transmission path between the input shaft and the output shaft, each extending parallel to the input shaft, and transmit power from the primary shaft to the secondary shaft by changing the speed. including a continuously variable transmission mechanism,
The primary shaft and the secondary shaft are divided into left and right sides with respect to the input shaft when viewed from the axial direction of the input shaft,
The primary shaft is located at a lower position than the input shaft,
The secondary shaft is arranged at a position above the input shaft,
A transmission in which a starter for starting the engine is disposed above the primary shaft.

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