JP2020139593A - transmission - Google Patents

Abstract

To provide a transmission having a new structure different from a structure of a conventional vertical CVT.SOLUTION: A vertical CVT 4 comprises an input shaft 41, a continuously variable transmission mechanism 42, a reverse transmission mechanism 43, and an output shaft 44. The continuously variable transmission mechanism 42 comprises a primary shaft 61, a secondary shaft 62, a primary pulley 63, a secondary pulley 64, and a belt 65. When a vehicle moves forward, power is transmitted to the primary shaft 61 from the input shaft 41, the power is transmitted to the secondary shaft 62 from the primary shaft 61 after a speed change, and it is transmitted to the output shaft 44 from the secondary shaft 62. When the vehicle moves backward, power is transmitted to the secondary shaft 62 from the input shaft 41, and the power is transmitted to the output shaft 44 from the secondary shaft 62.SELECTED DRAWING: Figure 3

Description

The present invention relates to a transmission.

In a vehicle equipped with an engine as a driving source for traveling, the power of the engine is transmitted to the drive wheels via a transmission. There are two types of engine mounting methods: vertical installation in which the crankshaft is oriented vertically with respect to the front-rear direction of the vehicle body, and horizontal installation in which the crankshaft is oriented horizontally. In vehicles that use the FF (Front-engine Front-wheel-drive) layout, for example, the engine is placed horizontally to increase the length of the passenger compartment by reducing the size of the engine compartment in the front-rear direction. Often installed. On the other hand, in vehicles that adopt the FR (Front-engine Rear-wheel-drive) layout, the engine is installed vertically because it is easy to transmit power to the rear wheels, which are the driving wheels. It may be installed.

A vertically installed CVT (Continuously Variable Transmission) has already been provided as a transmission for a vehicle in which an engine is installed vertically. The vertical CVT is arranged so that the input shaft into which the power of the engine is input is vertically oriented with respect to the front-rear 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 the primary shaft is on the same axis as the input shaft and the output shaft between the input shaft and the output shaft. (See, for example, Patent Document 1). The input shaft and the primary shaft are connected so as to be able to transmit power, and the power input from the engine to the input shaft is transmitted from the input shaft to the primary shaft. The secondary shafts are arranged parallel to the primary shaft at intervals, and an endless belt is wound between the primary pulley supported by the primary shaft and the secondary pulley supported by the secondary shaft. As a result, 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. Further, an intermediate shaft extending in parallel with the secondary shaft is provided, and the power transmitted to the secondary pulley is transmitted from the secondary shaft to the intermediate shaft via a gear, and the gear is transmitted from the intermediate shaft to the output shaft. It is transmitted through.

Japanese Unexamined Patent Publication No. 2012-192855

However, in the process of developing a new vehicle with an FR layout in which the engine is mounted vertically, it was found that the conventional vertical CVT structure cannot be adopted for the new vehicle.

An object of the present invention is to provide a transmission having a novel structure, which is different in structure from the conventional vertical CVT.

In order to achieve the above object, the transmission according to the present invention is a transmission mounted on a vehicle, and includes an input shaft into which power from a drive source is input, an output shaft extending in parallel with the input shaft, and the like. A stepless transmission mechanism provided on the power transmission path between the input shaft and the output shaft, having a primary shaft and a secondary shaft extending in parallel with the input shaft, respectively, and shifting and transmitting power from the primary shaft to the secondary shaft. The input shaft extends in the front-rear direction of the vehicle, and when the vehicle moves forward, power is transmitted from the input shaft to the primary shaft, and the power transmitted from the primary shaft to the secondary shaft is transmitted from the secondary shaft to the output shaft. Then, when the vehicle is moving backward, the power transmitted from the input shaft to the secondary shaft is transmitted from the secondary shaft to the output shaft.

According to this configuration, when the vehicle is moving forward, power is transmitted from the input shaft to the primary shaft, the power is transmitted by shifting from the primary shaft to the secondary shaft, and further transmitted from the secondary shaft to the output shaft. Therefore, when the vehicle is moving forward, the power can be transmitted by shifting the power from the input shaft to the output shaft.

On the other hand, when the vehicle is moving backward, power is transmitted from the input shaft to the secondary shaft, and the power is transmitted from the secondary shaft to the output shaft. Therefore, when the vehicle is moving backward, power can be transmitted from the input shaft to the output shaft without passing through the continuously variable transmission mechanism. Since the power does not pass through the continuously variable transmission mechanism, the power transmission efficiency is improved, so that the fuel efficiency of the vehicle equipped with the transmission can be improved. Further, since the hydraulic pressure for controlling the shift by the continuously variable transmission mechanism is not required, the effect of improving the fuel consumption can be obtained by the amount that the hydraulic pressure is not required. In addition, a driving feeling with a direct feeling (linear feeling) can be obtained when the accelerator is operated. Further, even if an overload is input to the vehicle from the road surface, the continuously variable transmission mechanism can be protected from the overload.

In addition, since a planetary gear mechanism for switching between forward and reverse of the vehicle is not required, the transmission can be miniaturized, and even if the vehicle has a low floor, such as a commercial vehicle. It is possible to mount the transmission on the vehicle while ensuring the minimum ground height of the vehicle.

Further, by reducing the size of the transmission, it is possible to reduce the weight of the transmission, and by extension, improve the fuel efficiency of the vehicle on which the transmission is mounted. In addition, the cost can be reduced by downsizing the transmission.

According to the present invention, it is possible to provide a vertical CVT 4 having a new structure, which is different in structure from the conventional vertical CVT, and even if the vehicle has a low floor, such as a commercial vehicle. It is possible to mount the longitudinal CVT on the vehicle while ensuring the minimum ground height of the vehicle.

It is sectional drawing which shows the structure of the transmission unit which concerns on one Embodiment of this invention. It is sectional drawing which shows by pulling out a part of the speed change unit from FIG. It is the figure which looked at the inside of the 2nd case of a transmission unit from the rear side (the side opposite to the engine side). It is a skeleton diagram which shows the structure of a vertical CVT and the power transmission path in a vertical CVT.

Hereinafter, 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 speed change unit 1 according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing a part of the speed change unit 1 extracted from FIG. 1 and enlarged. In the cross-sectional views after FIG. 1, the addition of hatching representing the cross section is omitted.

The speed change unit 1 is a unit mounted on a vehicle that shifts power generated by an engine (not shown) as a drive source for traveling. The vehicle adopts the FR layout, and the engine is mounted vertically with the crankshaft oriented vertically with respect to the front-rear direction of the vehicle body. The transmission unit 1 includes a torque converter 3 and a vertically installed CVT 4 in a unit case 2 forming 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 two cases 12 and the third case 13 are integrated by being fastened with bolts 14. The torque converter 3 is housed in the first case 11, and the vertical CVT 4 is housed in the second case 12 and the 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 rotation axis extending in the front-rear direction of the vehicle (vehicle body), and the outer peripheral end thereof is the rear side opposite to the engine side (the continuously variable transmission mechanism 42 side described later). It has a bent shape. The central portion of the front cover 21 bulges toward the front side. The crankshaft of the engine is connected to this bulging portion so that it cannot rotate relative to each other.

The pump impeller 22 is arranged on the vertical CVT4 side of the front cover 21. The outer peripheral end of the pump impeller 22 is connected to the outer peripheral end of the front cover 21 and is provided so as to be rotatable integrally with the front cover 21 around the rotation axis. A plurality of blades 27 are arranged in a radial pattern on the inner surface of the pump impeller 22.

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

The turbine runner 24 is fixed to the turbine hub 23. A plurality of blades 28 are arranged in a radial pattern 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, and its inner peripheral end is fitted onto the turbine hub 23 and is located between the front cover 21 and the turbine runner 24. When the hydraulic pressure of the engaging 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 releasing side oil chamber 34 on the front cover 21 side, the lockup piston 31 moves to the front cover due to the differential pressure. Move to the 21 side. Then, when the lockup piston 31 is pressed against the front cover 21, the pump impeller 22 and the turbine runner 24 are directly connected (lockup on). On the contrary, when the hydraulic pressure of the release side oil chamber 34 is higher than the hydraulic pressure of the engaging side oil chamber 33, the lockup piston 31 moves to the turbine runner 24 side due to the differential pressure. 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 attenuating vibration from the engine when the pump impeller 22 and the turbine runner 24 are directly connected.

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

When the pump impeller 22 is rotated by the engine torque in the lock-up-off state, an oil flow from the pump impeller 22 to the turbine runner 24 is generated. This oil flow is received by the blade 28 of the turbine runner 24, and the turbine runner 24 rotates. At this time, the amplification action 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 extends vertically in the front-rear direction of the vehicle.

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

The 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 (opposite side to the engine side) of the input shaft 41. The oil pump 46 includes a pump case 47 and a pump cover 48 that is superposed on the pump case 47. The pump case 47 and the pump cover 48 are fastened by a plurality of bolts and held in the 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 recessed on the rear side 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. .. As a result, 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 the pump shaft 54 is connected to the pump gear 49 so as not to rotate relative to each other. The pump shaft 54 penetrates the central portion 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 a portion of the torque converter 3 that bulges toward the front of the center of the front cover 21, and is coupled to the front cover 21 so as not to rotate relative to each other. 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 are rotated integrally 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 the bearing 45 and rotatably supported by the pump case 47 via the needle bearing 52 and the thrust bearing 53, and is rotatably supported by the turbine hub of the torque converter 3. When the turbine runner 24 rotates due to the spline fitting with the 23, the turbine runner 24 rotates integrally 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 view of the inside of the second case 12 as viewed from the rear side. Note that FIG. 1 is a cross-sectional view when the speed change unit 1 is cut along the cutting line planes AA shown in FIG.

The primary shaft 61 is arranged at a position where its axis is separated from the center of the input shaft 41 to the lower right when viewed from the rear side of the vehicle, and extends parallel to 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 axial direction (rotational radial direction) between the axis of the input shaft 41 and the axis of the primary shaft 61 is the turbine runner of the torque converter 3. It is shorter than the turning radius of 24.

The secondary shaft 62 is arranged at a position where its axis is separated from the axis of the input shaft 41 toward the upper left when viewed from the rear side of the vehicle, and extends parallel to 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 axial 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 axial distance between and, and shorter than the turning radius of the turbine runner 24 of the torque converter 3.

Therefore, when viewed in the front-rear direction of the vehicle, the axis of the primary shaft 61 and the axis of the secondary axis 62 are point-symmetrical with respect to the axis of the input shaft 41. Further, the primary shaft 61 and the secondary shaft 62 are positioned in the vertical direction between the uppermost position and the lowermost position of the turbine runner 24 of the torque converter 3, and face the turbine runner 24 in the front-rear direction. There is.

As shown in FIG. 1, the primary pulley 63 is arranged to face the primary fixed sheave 71 fixed to the primary shaft 61 and the primary fixed sheave 71 with the belt 65 sandwiched between them, and can move to the primary shaft 61 in the axial direction thereof. It also has a primary movable sheave 72 that is supported so that it cannot 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 inner peripheral end of the cylinder 73 is fixed to the primary shaft 61, extends in the axial direction from the primary shaft 61, and the outer peripheral end portion bends and extends rearward. The outer peripheral end of the primary movable sheave 72 is in liquidtight contact with the outer peripheral end of the cylinder 73 from the inside in the radial direction of rotation. 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 the secondary fixed sheave 75 fixed to the secondary shaft 62 and the secondary fixed sheave 75 with the belt 65 sandwiched between them, and is supported by the secondary shaft 62 so as to be movable in the axial direction and non-relatively rotatable. It is equipped with a secondary movable sheave 76. 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 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, that is, on the rear side with respect to the secondary movable sheave 76. The inner peripheral end of the piston 77 is 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 to the rear side, and the outer peripheral end of the piston 77 is in liquidtight contact with the outer peripheral end of the secondary movable sheave 76 from the inside in the radial direction of rotation. 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 overlap with a part of the primary movable sheave 72 and the cylinder 73 in the vertical direction (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 radial direction of rotation, and the secondary fixed sheave 75 is located at the outer peripheral end of the primary movable sheave 72. 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 piston chambers 74 and 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 to change 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 reduced, the hydraulic 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 to the primary fixed sheave 71 side, and the distance (groove width) between the primary fixed sheave 71 and the primary movable sheave 72 becomes smaller. Along with this, the winding diameter of the belt 65 with respect to the primary pulley 63 becomes large, and the distance (groove width) between the secondary fixed sheave 75 and the secondary movable sheave 76 of the secondary pulley 64 becomes large. As a result, the gear ratio becomes smaller.

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

A bias spring 69 is provided in the piston chamber 68 of the secondary pulley 64. One end of the bias spring 69 elastically contacts the secondary movable sheave 76, and the other end elastically contacts the piston 77. The elastic force of the bias spring 69 urges the secondary movable sheave 76 and the piston 77 in a direction in which they are separated from each other. The secondary movable sheave 76 is subjected to the hydraulic pressure in the piston chamber 68 and the urging force by the bias spring 69, and the belt 65 is subjected to the corresponding pinching pressure.

Further, 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 on the front side of the second primary shaft 82. The primary pulley 63 is supported by the second primary shaft 82. A circular connecting 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. .. The front end of the first primary shaft 81 is rotatably supported by the first case 11 via a bearing 84. The front end of the second primary shaft 82 is rotatably supported by the second case 12 via a bearing 85. An adapter 86 held in 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, the input shaft 41 is integrally formed with an input shaft gear 91 in a portion adjacent to the rear side of a portion in which the inner ring (inner race) of the bearing 45 is fitted. Correspondingly, the primary input gear 92 is supported on the first primary shaft 81 so as to be relatively rotatable via the 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 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 part of the forward clutch 94 overlaps with the oil pump 46 in the rotational radial direction (overlaps 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 inner peripheral end of the clutch drum 95 is fixed to the first primary shaft 81, extends in the radial direction from the first primary shaft 81, and the outer peripheral end portion bends and extends toward the primary input gear 92, that is, the front side. A plurality of clutch plates 101 are held side by side at the outer peripheral end of the clutch drum 95 at intervals in the front-rear direction.

The clutch hub 96 is integrally formed with the 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 of the clutch drum 95 at intervals from the inside in the radial direction of rotation. A plurality of clutch discs 102 are held in the clutch hub 96 at intervals in the front-rear direction. The clutch plate 101 and the clutch disc 102 are arranged so as to be 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-rear direction. The clutch piston 97 extends from the first primary shaft 81 outward in the axial direction of the first primary shaft 81, and the outer peripheral end portion is bent forward and extends. The tip of the outer peripheral end of the clutch piston 97 comes into contact with the clutch plate 101. Further, the clutch piston 97 is in liquid-tight contact with the clutch drum 95, and a piston chamber 103 to which hydraulic pressure acting on the clutch piston 97 is supplied is formed between the clutch drum 95 and the clutch piston 97. ing.

The canceller 98 is provided between the clutch hub 96 and the clutch piston 97. The 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. As a result, the 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 in which they are separated from each other by the urging force of the return spring 105.

The clutch piston 97 moves toward the clutch plate 101 by the hydraulic pressure supplied to the piston chamber 103 and presses the clutch plate 101. By this pressing, the clutch plate 101 and the clutch disc 102 are in pressure contact with each other, and the forward clutch 94 is engaged. The engagement of the forward clutch 94 prohibits the 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 integrally 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 by 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 the clutch disc 102 and the clutch plate 101 is released, and the forward clutch 94 is released. The release 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 divided into a first secondary shaft 111 and a second secondary shaft 112. The first secondary shaft 111 is arranged on the front side of the second secondary shaft 112. The secondary pulley 64 is supported by the second secondary shaft 112. A circular connecting 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 is understood in comparison with the first primary shaft 81. By sharing the first primary shaft 81 and the first secondary shaft 111, the number of types of parts constituting the speed change unit 1 (vertical CVT4) can be reduced, and the manufacturing cost of the speed change unit 1 can be reduced. .. The front end of the first secondary shaft 111 is rotatably supported by the first case 11 via a bearing 114. The front end of the second secondary shaft 112 is rotatably supported by the second case 12 via a bearing 115. The 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 on the second secondary shaft 112 on the rear side of the bearing 114 so as to be relatively rotatable via the needle bearing 122.

A reverse clutch 123 is provided that allows / prohibits rotation of the secondary input gear 121 with respect to the first secondary shaft 111 by utilizing the space between the secondary input gear 121 and the pump case 47 of the oil pump 46. A part of the reverse clutch 123 overlaps with the oil pump 46 in the rotational radial direction (overlaps 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 inner peripheral end of the clutch drum 124 is fixed to the first secondary shaft 111, extends from the first secondary shaft 111 in the shaft radial direction, and the outer peripheral end portion bends and extends toward the secondary input gear 121, that is, the front side. A plurality of clutch plates 131 are held side by side at the outer peripheral end of the clutch drum 124 at intervals in the front-rear direction.

The clutch hub 125 is integrally formed with the 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 at a distance from the inside in the radial direction of rotation. A plurality of clutch discs 132 are held in the clutch hub 125 at intervals in the front-rear direction. The clutch plate 131 and the clutch disc 132 are arranged so as to be arranged alternately in the central axis direction. The number of each of the clutch plates 131 and the clutch disc 132 is larger than the number of each of the clutch plates 101 and the clutch disc 102 of the 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-rear direction. The clutch piston 126 extends from the first secondary shaft 111 outward in the axial direction of the first secondary shaft 111, and the outer peripheral end portion is bent forward and extends. The tip of the outer peripheral end of the clutch piston 126 comes into contact with the clutch plate 131. Further, the clutch piston 126 is in liquid-tight contact with the clutch drum 124, and a piston chamber 133 to which hydraulic pressure acting on the clutch piston 126 is supplied is formed between the clutch drum 124 and the clutch piston 126. ing.

The canceller 127 is provided between the clutch hub 125 and the clutch piston 126. The 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, the 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 in which they are separated from each other by the urging force of the return spring 135.

The clutch piston 126 moves toward the clutch plate 131 by the hydraulic pressure supplied to the piston chamber 133, and presses the clutch plate 131. By this pressing, the clutch plate 131 and the clutch disc 132 are in pressure contact with each other, and the reverse clutch 123 is engaged. The engagement of the reverse clutch 123 prohibits the 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 clutch piston 126 is separated from the clutch plate 131 by 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 the clutch disc 132 and the clutch plate 131 is released, and the reverse clutch 123 is released. By releasing the reverse clutch 123, the 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. The 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. The front end of the reverse shaft 141 is rotatably supported by the first case 11 via a bearing 144. The rear end of the reverse shaft 141 is rotatably supported by the second case 12 via a bearing 145. Further, as shown in FIG. 3, the position of the reverse shaft 141 in the vertical direction is set between the uppermost position and the lowermost position of the turbine runner 24 of the torque converter 3, and the reverse shaft 141 is located in the front-rear direction with the turbine runner 24. Facing each other.

The first reverse gear 142 is integrally formed 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 arranged 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 so as to have a common axis extending vertically along the front-rear direction of the vehicle in the front-rear direction at intervals in the front-rear direction.

The front end of the output shaft 44 is rotatably supported by the 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 (overlapping when viewed from the rotational radial direction of the secondary pulley 64). As a result, the output shaft 44 is brought close to the secondary movable sheave 76 to the utmost limit, and is arranged so as to overlap the piston 77 in the front-rear direction. As a result, the front-rear length of the transmission unit 1 (vertical CVT4) is shortened. Further, the output shaft 44 is rotatably supported by the third case 13 via the bearing 147 in which the inner ring of the bearing 147 is externally fitted in a portion spaced rearward from the support portion by the needle bearing 146. Has been done.

An output shaft gear 148 is integrally formed on the output shaft 44 between the support portion by the needle bearing 146 and the support portion by the bearing 147. Correspondingly, the secondary output gear 149 is supported on the secondary shaft 62 (second secondary shaft 112) adjacent to the rear side of the piston 77 of the secondary pulley 64 by spline fitting so as not to rotate relative to each other. .. The output shaft gear 148 and the secondary output gear 149 are meshed 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 (overlaps when viewed in the front-rear direction).

<Valve body>
A valve body 151 is provided on the bottom of the second case 12. The valve body 151 is formed with a hydraulic circuit including various valves for controlling the supply of oil to each part of the transmission unit 1. The 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. By the rotation of the pump gear 49 of the oil pump 46, the oil stored in the oil pan 152 is sucked up through the strainer and supplied to the valve body 151. Then, oil is supplied from the valve body 151 as hydraulic oil or lubricating oil 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 axial direction of the primary shaft 61 at a position overlapping the oil pump 46 in the front-rear 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 piston chamber 103 is closer to the oil pump 46 as compared with the configuration in which the configuration of the forward clutch 94 is reversed back and forth. .. Therefore, in the configuration of the forward clutch 94, the distance from the oil passage 153 to the piston chamber 103 can be shortened, and the oil passage length from the oil pump 46 to the piston 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 piston chamber 133 of the reverse clutch 123 through an oil passage 154 extending upward from the valve body 151 along the axial direction of the primary shaft 61 at a position overlapping the oil pump 46 in the front-rear 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 piston chamber 133 is closer to the oil pump 46 as compared with the configuration in which the configuration of the reverse clutch 123 is reversed back and forth. .. 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 oil passage length from the oil pump 46 to the piston chamber 133 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.

Further, as shown in FIG. 3, a partition wall 155 is formed in the second case 12. The partition wall 155 extends along the outer circumference of the primary pulley 63 to a position facing the left end of the primary pulley 63 in the vertical direction beyond the position facing the lower end of the primary pulley 63 in the vertical direction toward the secondary pulley 64. It bends and extends to the lower left side 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 portion of the primary pulley 63 from being immersed in the oil. Further, 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 scratched by the primary pulley 63 to the open end side of the partition wall 155. Is issued. As a result, it is possible to prevent the lower portion of the primary pulley 63 from being immersed in the oil, reduce the mechanical loss caused by the oil acting as a resistance to the rotation of the primary pulley 63, and improve the fuel efficiency of the vehicle.

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

When the vehicle moves forward, the forward clutch 94 is engaged and the reverse clutch 123 is released. The 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 the 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 secondary input gear 121 becomes the secondary shaft 62 due to the release of the reverse clutch 123. It slips with respect to (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 gear ratio corresponding to the pulley ratio between the primary pulley 63 and the secondary pulley 64, and is transmitted to the secondary shaft 62. Then, 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, output from the output shaft 44 to the propeller shaft (not shown), and 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 the primary input gear 92 is larger than the gear diameter of the input shaft gear 91, the power of the input shaft 41 is decelerated by the input shaft gear 91 and the primary input gear 92 and transmitted to the 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 decelerated by the secondary shaft gear 149 and the output shaft gear 148 and transmitted to the output shaft 44. .. Therefore, when the vehicle is moving forward, the input shaft gear 91 and the primary input gear 92 form a primary reduction gear mechanism 156 that reduces 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 output shaft gear 148 The secondary shaft gear 149 further constitutes a secondary reduction gear mechanism 157 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 157 is omitted can be considered. 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 is increased. There is a need to. By increasing the gear diameter of the primary input gear 92, the size of the vertical CVT 4 increases. Therefore, in the configuration including the secondary reduction gear mechanism 157 in addition to the primary reduction gear mechanism 156, the vertical CVT 4 can be downsized as compared with the configuration in which the secondary reduction gear mechanism 157 is omitted.

Further, 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 provided 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 made to correspond to the changed specifications of the engine.

When the vehicle is moving backward, the forward clutch 94 is released and the reverse clutch 123 is engaged. The 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 the engagement of the reverse clutch 123. .. At this time, the secondary shaft 62 rotates in the direction opposite to that when the vehicle is moving forward. On the other hand, even if the power input to the input shaft 41 is transmitted from the input shaft gear 91 to the primary input gear 92 and the primary input gear 92 rotates, the primary input gear 92 becomes the primary shaft 61 due to the release of the forward clutch 94. It slips with respect to (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, output from the output shaft 44 to the propeller shaft, and from the propeller shaft to the rear differential gear and the drive shaft. It is transmitted to the left and right rear wheels via.

Since 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 decelerated 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 decelerated by the secondary shaft gear 149 and the output shaft gear 148 and transmitted to the output shaft 44. .. Therefore, when the vehicle is moving backward, the input shaft gear 91, the reverse transmission mechanism 43, and the secondary input gear 121 form a primary reduction gear mechanism 158 that reduces the power in the power transmission path from the input shaft 41 to the output shaft 44. The output shaft gear 148 and the secondary shaft gear 149 form a secondary reduction gear mechanism 157 that further reduces the power.

<Action effect>
As described above, the primary shaft 61 and the secondary shaft 62 are separately arranged on the left and right sides with respect to the input shaft 41. As a result, the vertical distance between the primary shaft 61 and the secondary shaft 62 in the vertical direction can be shortened, and the vertical size of the vertical CVT 4 can be reduced. In the speed change unit 1, the size of the continuously variable transmission mechanism 42 in the vertical direction is reduced to such an extent that the vertical positions of the primary shaft 61 and the secondary shaft 62 fit between the uppermost position and the lowest position of the torque converter 3. ing. Therefore, even in a vehicle such as a commercial vehicle having a low floor, it is possible to mount the speed change 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 with respect to the input shaft 41, 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, in the engine compartment in which the transmission unit 1 is housed, a space can be provided above the primary shaft 61, and a starter 161 or the like for starting the engine can be arranged in the 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 arranged between the primary shaft 61 and the secondary shaft 62. By arranging the oil pump 46 by making good use of the space between the primary shaft 61 and the secondary shaft 62, the size of the vertically installed CVT 4, particularly the size in the front-rear direction can be reduced.

Further, in the vertical CVT 4, when the vehicle is moving forward, power is transmitted from the input shaft 41 to the primary shaft 61, the power is transmitted by shifting from the primary shaft 61 to the secondary shaft 62, and further, the power is transmitted from the secondary shaft 62 to the output shaft 44. Is transmitted to. Therefore, when the vehicle is moving forward, the power can be changed and transmitted from the input shaft 41 to the output shaft 44.

On the other hand, when the vehicle is moving backward, power is transmitted from the input shaft 41 to the secondary shaft 62, and the power is transmitted from the secondary shaft 62 to the output shaft 44. Therefore, when the vehicle is moving backward, 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 consumption of the vehicle equipped with the longitudinal CVT 4 can be improved. Further, since the hydraulic pressure for controlling the shift by the continuously variable transmission mechanism 42 is not required, the effect of improving the fuel consumption can be obtained by the amount that the hydraulic pressure is not required. In addition, a driving feeling with a direct feeling (linear feeling) can be obtained when the accelerator is operated. Further, 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.

Further, since the planetary gear mechanism for switching between forward and reverse of the vehicle is unnecessary, 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. As a result, pinching pressure can be applied to the belt 65 by the primary movable sheave 72 and the secondary movable sheave 76 from both sides thereof, and the occurrence of slippage of the belt 65 can be suppressed.

In the secondary pulley 64, the outer peripheral end of the piston 77 comes into liquid-tight contact with the outer peripheral end of the secondary movable sheave 76 from the inside in the radial direction of rotation. Therefore, the size of the secondary movable sheave 76 in the front-rear direction is larger than the size of the primary movable sheave 72 in the front-rear direction. Therefore, in a configuration in which the primary movable sheave 72 is arranged on the rear side (opposite to the engine side) of the primary fixed sheave 71 and the secondary movable sheave 76 is arranged on the front side (engine side) of the secondary fixed sheave 75. The position of the belt 65 in the axial direction is rearward as compared with the configuration in which the primary movable sheave 72 is arranged on the front side with respect to the primary fixed sheave 71 and the secondary movable sheave 76 is arranged on the rear side with respect to the secondary fixed sheave 75. The shift to the side causes the continuously variable transmission mechanism 42 including the primary pulley 63, the secondary pulley 64, and the belt 65 to become longer in the front-rear direction.

Therefore, the primary movable sheave 72 is arranged on the front side with respect to the primary fixed sheave 71, and the secondary movable sheave 76 is arranged on the rear side with respect to the secondary fixed sheave 75, so that the length of the continuously variable transmission mechanism 42 in the front-rear direction is long. It is possible to shorten the length. Then, by arranging other members such as the output shaft 44 in the space created thereby and overlapping the other members in the axial radial direction of the secondary pulley 64 and the input shaft 41, the length in the axial direction is kept short. The size in the axial direction can also be reduced.

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

Therefore, it is possible to reduce the size of the vertical CVT4, and even if the vehicle has a low floor such as a commercial vehicle, the vehicle must be equipped with the transmission unit 1 including the vertical CVT4 at the minimum. It is possible to secure the ground clearance.

Further, by reducing the size of the vertically installed CVT 4, the weight of the transmission unit 1 can be reduced, and the fuel consumption of the vehicle on which the transmission unit 1 is mounted can be improved. Further, the cost can be reduced by downsizing the speed change unit 1.

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

For example, the power transmission system of the continuously variable transmission mechanism 42 is not limited to the belt type, but may be a chain type or a toroidal type.

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

4: Vertical CVT (transmission)
41: Input shaft 42: Continuously variable transmission mechanism 44: Output shaft 61: Primary shaft 62: Secondary shaft 63: Primary pulley 64: Secondary pulley

Claims (1)

A transmission mounted on a vehicle
The input shaft to which the power from the drive source is input and
An output shaft extending parallel to the input shaft and
It has a primary shaft and a secondary shaft that are provided on a power transmission path between the input shaft and the output shaft and extend in parallel with the input shaft, respectively, and transmit power by shifting power from the primary shaft to the secondary shaft. Including a stepless speed change mechanism
The input shaft extends in the front-rear direction of the vehicle.
When the vehicle is moving forward, power is transmitted from the input shaft to the primary shaft, and power transmitted from the primary shaft to the secondary shaft is transmitted from the secondary shaft to the output shaft.
A transmission in which power transmitted from the input shaft to the secondary shaft is transmitted from the secondary shaft to the output shaft when the vehicle is moving backward.

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