JPH0650940U - Axle drive with hydraulic continuously variable transmission - Google Patents

Abstract

(57) [Abstract] [Purpose] A hydraulic continuously variable transmission equipped with an auxiliary transmission on the output side can be easily changed to a specification with or without an auxiliary transmission. A mechanical auxiliary transmission is arranged at one end of a hydraulic continuously variable transmission, a differential device and an axle are arranged at the other end, and a motor shaft 21 of the hydraulic continuously variable transmission is formed in a hollow shape. In addition to transmitting power to the mechanical auxiliary transmission, the output shaft 26 of the auxiliary transmission transmits the power to the differential device D1 through the hollow motor shaft 21.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a configuration of an axle drive device with a hydraulic continuously variable transmission, which is used in a traveling vehicle such as a tractor.

[0002]

[Prior art]

 Conventionally, a hydraulic continuously variable transmission is attached to a mission case, the motor shaft of the hydraulic continuously variable transmission is projected into the mission case, and the motor shaft between the differential device and the motor shaft arranged in the mission case is projected. A transmission in which a mechanical auxiliary transmission is arranged is known. For example, it is a technique disclosed in Japanese Utility Model Laid-Open No. 63-27758.

[0003]

[Problems to be solved by the device]

 In such a conventional transmission, a small traveling vehicle or a traveling vehicle with a light load may not require the auxiliary transmission. In such a case, the easiest way to deal with this is to remove the sub-transmission and modify it so that the motor shaft and differential are directly connected.However, a large, useless space is left inside the mission case excluding the sub-transmission. The mission case is still large and cannot be made compact. In addition, the modification of the mission case itself by replacing it with a small one that eliminates wasted space lacks cost merit.

[0004]

[Means for Solving the Problems]

 The problem to be solved by the present invention is as described above. Next, the means for solving the problem will be described. That is, the mechanical auxiliary transmission is arranged at one end of the hydraulic continuously variable transmission, the differential device and the axle are arranged at the other end, and the motor shaft of the hydraulic continuously variable transmission is formed in a hollow shape. In addition to transmitting power to the mechanical auxiliary transmission, the output shaft of the mechanical auxiliary transmission transmits power to the differential through the hollow motor shaft.

[0005]

[Action]

 In such a structure, the power transmitted to the input shaft 3 of the hydraulic continuously variable transmission drives the hydraulic pump P, and the driving of the hydraulic pump P causes the motor shaft 21 of the hydraulic motor M to rotate. Is driven by a mechanical auxiliary transmission device from a gear 25 fixedly mounted on the motor shaft 21 to drive an output shaft 26, and the output shaft 26 penetrates the inside of the motor shaft 21 and has a rear end pinion 26a. Power is transmitted to the differential device D1. When the mechanical auxiliary transmission is not required, the motor shaft 21 and the output shaft 26 are directly connected to each other to transmit power.

[0006]

【Example】

 The problems to be solved by the invention and the means for solving the problems are as described above. Next, an embodiment of the invention will be described. FIG. 1 is a side view of a work vehicle equipped with the transmission of the invention, and FIG. 2 is power transmission. FIG. 3 is a skeleton diagram showing the mechanism, FIG. 3 is a side sectional view of the transmission case, FIG. 4 is a side sectional view of the direct coupling portion with the auxiliary transmission removed, and FIG. 5 is a front view showing the disposition of the transmission shaft.

The overall configuration of the work vehicle will be described with reference to FIG. 1. An engine E is arranged in a front side of the body 1 in a bonnet 1, and a transmission arranged in the rear part of the body from an output shaft of the engine E via a universal joint 2. The power is transmitted to the input shaft 3 of the transmission T, and the gears are changed in the transmission T to change the rear wheel 4, the front wheel 5 through the universal joint 7, and the mower as the mid-mount working machine 6 through the universal joint 8. Can be driven respectively.

The structure of the transmission T and the power transmission mechanism will be described in detail with reference to FIGS. 2, 3 and 5. Power from the engine E is transmitted from the main clutch 10 to the input shaft 3 of the transmission T via the universal joint 2. Reportedly. The transmission T has a first case 11 fixed to the front side of the main plate 9 and a second case 12 fixed to the rear side thereof. The input shaft 3 is a pump of a hydraulic pump P of a hydraulic continuously variable transmission. As a shaft, it penetrates through the main plate 9 and is rotatably mounted horizontally on the first case 11 and the second case 12. On the input shaft 3 in the first case 11, a hydraulic multi-plate type work machine clutch is provided. 13, the power can be transmitted from the gear 14 fitted on the input shaft 3 to the gear 16 on the PTO shaft 17 via the intermediate gear 15, and the mid-mount working machine 6 can be driven from the PTO shaft 17. There is.

The second case 12 is divided into a front case 12a and a rear case 12b by a bearing wall. A hydraulic pump P is arranged on the input shaft 3 in the front case 12a, and the hydraulic pump P has a cylinder block 18 for accommodating the piston inserted and retracted fitted on the input shaft 3 so that the piston block The head is brought into contact with the movable swash plate 19, and the movable swash plate 19 is tilted by the rotation of the speed change lever 20. Due to this tilt, the discharge direction and discharge amount of the pressure oil from the hydraulic pump P 1 are changed, and the hydraulic motor The M is continuously variable.

The motor shaft 21 of the hydraulic motor M is hollow and rotatably mounted horizontally between the main plate 9 and the front case 12 a. One end of the motor shaft 21 is projected into the first case 11 and the gear is rotated. 25 are fixed. The cylinder block 23, which is fitted with the pistons 22, 22, ... in a retractable manner, is externally fitted onto the motor shaft 21 in the front case 12a, and the pistons 22, 22. The hydraulic motor M is constructed by contacting the plate 24. The hydraulic pump P and the cylinder blocks 18 and 23 of the hydraulic motor M are hydraulically connected via an oil passage in the main plate 9.

An output shaft 26 is rotatably inserted into the inside of the motor shaft 21, and a pinion 26a is formed at a rear end of the motor shaft 21. The pinion 26a drives a bevel gear 27 to a shaft 29 through a differential device D1. Is transmitted to drive the rear wheels 4 and power is transmitted to the front end of the output shaft 26 via the universal joint 7 to the front differential device D2 so that the front wheels 5 can be driven. A gear 31 is fitted onto the output shaft 26 by a key 30 so that the gear 31 cannot rotate relative to the output shaft 26 but can slide in the axial direction.

A clutch claw 31 a is formed on a side surface of the gear 31, and a clutch claw 25 a formed on a side surface of a gear 25 fixed on the motor shaft 21 by sliding the gear 31. The small gear 33a also meshes with the small gear 33a fixedly mounted on the auxiliary transmission shaft 32 rotatably laterally mounted between the first case 11 and the main plate 9. The large-diameter gear 33b that rotates integrally with 33a always meshes with the gear 25. When the gear 31 is slid to engage the clutch pawl 31a and the clutch pawl 25a, the motor shaft 21 and the output shaft 26 are directly connected to each other to achieve high speed shifting. When the gear 31 is slid to engage the small diameter gear 33a. From the motor shaft 21, it is transmitted to the output shaft 26 via the gear 25, the large diameter gear 33b, the small diameter gear 33a, and the gear 31, and the gear shifts to a low speed to form an auxiliary transmission.

In such a configuration, when the mechanical auxiliary transmission is not required, as shown in FIG. 4, the auxiliary transmission shaft 32, the small diameter gear 33a, and the large diameter gear 33b are removed, and the gear 25 of the gear 25 is removed. The clutch pawl 25a and the clutch pawl 31a of the gear 31 are meshed with each other so that the spacer 35 is fitted over the output shaft 26 so that the clutch pawl does not come off. The space-saving first case 11 'is fixed to the main plate 9 so that only a part of the case of the transmission T can be changed without changing the whole case of the transmission T.

It is also possible to drive the front wheels 5 together with the rear wheels 4 only when the auxiliary transmission is at a low speed. As shown in FIG. 6, the output shafts are the front output shaft 26F and the rear output shafts. The shaft 26R is divided into two and arranged on the same shaft core, and is supported in the first case 11. The front output shaft 26F has a clutch pawl 26b formed at the rear end, and the rear output shaft 26R is a motor. A gear 31 ′ which is fitted in and supported by the shaft 21 and meshes with a large-diameter gear 33 b on the auxiliary transmission shaft 32 in the same manner as described above so as to be slidably fitted on the rear output shaft 26 R. The small diameter gear 33a and the clutch claw 31'a can mesh with the clutch claw 25a. When the gear 31 'meshes with the small diameter gear 33a, the clutch pawl 31b provided at the front end of the gear 31' meshes with the clutch pawl 26b of the front output shaft 26F to transmit the low speed rotation to the front wheel 5. When the clutch pawl 31'a of the gear 31 'meshes with the clutch pawl 25a, the clutch pawl 31b and the clutch pawl 26b are disengaged, and only the rear wheel 4 is driven at high speed.

[0015]

[Effect of device]

 Since the present invention is configured as described above, it has the following effects. That is, since the output shaft of the mechanical auxiliary transmission is fitted inside by penetrating the hollow motor shaft, a compact transmission structure can be obtained when transmitting power, and power can be output back and forth. In addition, the mechanical auxiliary transmission is located at one end of the hydraulic continuously variable transmission, and the differential device and the axle are located at the other end. By installing a separate first case that was omitted, it was possible to reduce the size of the entire mission case without changing it, and it was possible to easily respond to the request for the presence or absence of the auxiliary transmission. Of.

[Brief description of drawings]

FIG. 1 is a side view of a work vehicle equipped with a transmission of the present invention.

FIG. 2 is a skeleton diagram showing a power transmission mechanism.

FIG. 3 is a side sectional view of a mission case.

FIG. 4 is a side cross-sectional view of the direct coupling portion with the auxiliary transmission removed.

FIG. 5 is a front view showing an arrangement of transmission shafts.

FIG. 6 is a partial side cross-sectional view showing an embodiment including a clutch that switches to a front-wheel drive state only when the auxiliary transmission is at a low speed.

[Explanation of symbols]

 P hydraulic pump M hydraulic motor D1 differential device 21 motor shaft 26 output shaft 29 axle

Claims (1)

[Scope of utility model registration request] 1. A mechanical auxiliary transmission is arranged at one end of a hydraulic continuously variable transmission, a differential device and an axle are arranged at the other end thereof, and a motor shaft of the hydraulic continuously variable transmission is hollow. A hydraulic continuously variable transmission characterized in that the output shaft of the mechanical auxiliary transmission device is transmitted to the differential device through the hollow motor shaft while being formed and transmitting power to the mechanical auxiliary transmission device. Axle drive with device.