JPH0544816A - Transmission for wheeled vehicle - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a transmission for a wheeled vehicle in which the power distribution to a work machine and a traveling device can be varied according to the purpose. [Structure] An engine input section 10 directly connected to an engine 2 is provided on one side of a transmission 1, and a motor input directly connected to a hydraulic motor 3 whose hydraulic source is a hydraulic pump 4 driven by the engine 2 is provided on the other side. A section 40 is provided. At the center of the transmission 1, a planetary gear transmission 20 including two sets of planetary gear units 21 and 22 connected to the input units 10 and 40 is provided, and an output unit 50 having a reduction gear 52 is further provided. Set up. When traveling in the low speed range, the hydraulic motor is driven, and the power distribution between the working machine and the traveling device can be arbitrarily changed by increasing or decreasing the amount of oil supplied to the hydraulic motor 3. Also, it becomes possible to run at ultra-low speed with high traction force without stopping the engine.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission for a wheeled vehicle.

[0002]

2. Description of the Related Art In a wheeled construction machine such as a motor grader, a mechanical drive type speed change device has been conventionally used as a speed change means. FIG. 4 shows an example thereof, which includes three high speed stages and three low speed stages for forward and backward travel. In the figure, the output torque of the engine 2 is transmitted to the input shaft 11 of the transmission 1 via the reduction gears 5 and 6. 2 for reverse (R) and forward (F) on the input shaft 11.
A set of planetary gear units 61, 62 is arranged, and the planetary gear unit 6 for the third speed, the second speed and the low speed (L) is provided on the intermediate shaft 63.
4, 65, 66 and first-speed and high-speed (H) direct coupling clutches 67, 68 are provided. The output shaft 69 of the transmission 1 is connected to the planet carrier 70 of the low speed planetary gear unit 66, and is output via the reduction gears 71 and 72. A hydraulic pump provided as a hydraulic source of a hydraulic actuator that drives each working machine is driven by the engine 2 via a reduction gear (not shown).

[0003]

In the motor grader, there are work forms such as ground leveling, ripping, and snow removal, and the work is performed while traveling. However, the conventional power transmission system has the following problems. (1) It is not possible to freely change the power distribution to the working machine and the traveling device. The engine horsepower PE is divided into PT which becomes a traveling power via a transmission and PP which becomes a power to drive a working machine hydraulic pump through a reduction gear. In the conventional power transmission system shown in FIG. The distribution ratio between PT and PP cannot be freely changed. For example, if you want to raise PP by lowering the vehicle speed, traction force, or PT, if you lower PE to lower PT, PP will also drop. If the hydraulic pressure of the hydraulic pump rises with PP lowered, the engine will stop. It may happen. Therefore, it is impossible to keep the engine power PE full and distribute all the power other than the power required by PT as PP. (2) Cannot run at ultra-low speed and high traction. Ultra-low speed running means running at around 0 km / h without stopping the engine. Since the transmission is directly connected to the engine, when a large traveling load is applied, the engine stops at a certain lower engine speed below the engine maximum torque point. In addition, when the engine speed is reduced by narrowing PE such as low idling rotation, the engine torque is also reduced, so no force is applied. When the running load exceeds the torque at this time, the engine stops. (3) Fine speed adjustment is not possible. The fine speed adjustment traveling means traveling at an arbitrary vehicle speed without changing the engine speed even if there is a load change, and is generally traveling in a low speed region. In the motor grader, in the case of leveling work and ripping work, in the case of wheeled excavator loaders, crane trucks, etc. when traveling with hanging loads, or when these vehicles escape from the muddy state, etc. Is done. As described above, the conventional power transmission system does not have the function of changing the power distribution ratio between the working machine and the traveling device, the stall function, or the creep function.
Fine speed adjustment traveling is not possible.

In view of the above-mentioned conventional problems, the present invention aims to provide a transmission for a wheeled vehicle in which the power distribution to the working machine and the traveling device can be varied according to the purpose. And

[0005]

In order to achieve the above object, a transmission for a wheeled vehicle according to the present invention connects an input shaft on one side of the transmission to an output shaft of an engine, and through this input shaft. The engine input section for inputting the output torque of the engine and the output axis of the hydraulic motor driven by the engine that can rotate in the forward and reverse directions are connected to the input shaft on the other side of the transmission. A motor input unit for inputting the output torque of the hydraulic motor via a shaft, a planetary gear transmission unit composed of two sets of planetary gear units, an output shaft and an output gear unit fixed to the output shaft. And a part, and in such a structure,
The engine input section includes a direct coupling clutch attached to the input shaft, and the motor input section includes a reduction gear that rotates by engagement of the direct coupling clutch attached to the input shaft and a reduction gear that meshes with the reduction gear. And an intermediate shaft connected to the direct coupling clutch of the engine input section, a rotary clutch,
The two sets of sun gears of the planetary gear device and the reduction gear large gear of the motor input section are attached, and the planetary carrier of the planetary gear device on one side is connected to the reduction small gear rotated by the engagement of the rotary clutch, A planet gear of the planetary gear set on one side is connected to a planet gear of the planetary gear set on the other side, and a small reduction gear that is rotated by the engagement of the rotary clutch is engaged with a large reduction gear fixed to the output shaft. did.

[0006]

According to the above construction, the engine input portion directly connected to the output shaft of the engine and the motor input portion directly connected to the output shaft of the hydraulic motor are provided at both ends of the transmission, and the engine input portion and the motor input portion are connected. In both cases, since the traveling power is transmitted through the planetary gear transmission and the output, the amount of oil supplied to the hydraulic motor is changed to increase or decrease the traveling power input from the motor input to the transmission. Is possible. Therefore, when the power is input from the motor input unit, the power distribution to the work machine and the traveling device can be freely changed, and the torque hardly decreases even if the hydraulic motor rotation speed is reduced, so that the speed is extremely low and high. You will be able to perform traction driving and fine speed adjustment driving.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of a transmission for a wheeled vehicle according to the present invention will be described below with reference to the drawings. The transmission 1 includes an engine input unit 10 for inputting the output torque of the engine 2, a planetary gear transmission unit 20, a motor input unit 40 for inputting the output torque of the hydraulic motor 3, and an output unit 50. The engine input unit 10 includes an input shaft 11 directly connected to the output shaft of the engine 2 and a direct connection clutch 12 attached to the input shaft 11. Further, the planetary gear transmission unit 20 is connected to two sets of planetary gear units 21 and 22, a reduction gear 24 connected to the planet carrier 23 of the planetary gear unit 21, and the direct coupling clutch 12 to form a reduction gear 24. It is composed of an engaging rotary clutch 25 and an intermediate shaft 29 for fixing the sun gears 27, 28 of the two sets of planetary gear units 21, 22. The planetary gear device 21,
22 includes ring gear fixed clutches 31 and 32, respectively. The planet gear 34 of the planetary gear device 22 is connected to the ring gear 33 of the planetary gear device 21.

The hydraulic motor 3 uses a hydraulic pump 4 driven by the engine 2 as a hydraulic source and can rotate in both forward and reverse directions. The motor input section 40 is attached to the input shaft 41 and the input shaft 41. The direct coupling clutch 42, and the reduction small gear 43 and the reduction large gear 44 driven by the engagement of the direct coupling 42. The reduction gear 44 is fixed to the end of the intermediate shaft 29. The output unit 50 is composed of an output shaft 51 and a large reduction gear 52 fixed to the output shaft 51 and meshing with the small reduction gear 24. It should be noted that a part of the pressure oil discharged by the hydraulic pump 4 is part of the transmission 1
It is used for lubrication.

In the transmission having the above-mentioned structure, when the hydraulic motor 3 is used as a drive source, forward and backward three stages can be switched in a low speed range, and when the engine 2 is used as a drive source, three forward stages are used in a high speed range. Can be switched. Table 1 summarizes an example of the drive source, the engagement clutch code (see FIG. 1), and the reduction gear ratio at each speed stage. A circle mark in the table indicates a corresponding drive source or an engaged clutch.

[Table 1]

The respective power transmission paths will be described below by taking the low speed forward and backward first speed and the high speed forward second speed as an example. In the case of the low speed forward / reverse first speed, the output torque of the hydraulic motor 3 drives the reduction small gear 43 through the engaged direct coupling clutch 42, and the reduction large gear 44 meshing with the reduction small gear 43 and the planetary gear units 21 and 22. The sun gears 27 and 28 are driven. Here, since the ring gear fixed clutch 31 of the planetary gear device 21 is engaged, the power is transmitted to the reduction gear 24 through the planet carrier 23 of the planetary gear device 21. Then, the large reduction gear 5 meshing with the small reduction gear 24
The power transmitted to 2 is taken out through the output shaft 51.

Now, the reduction ratio ρ1 of the small reduction gear 43 to the large reduction gear 44 is 2.67, and the reduction ratio ρ2 of the planetary gear unit 21.
Is 2.69 and the reduction ratio ρ3 of the small reduction gear 24 to the large reduction gear 52 is 1.00, the total reduction ratio is ρ1 × ρ2 × ρ3
= 7.18.

With a hydraulic motor input, as shown by the dotted lines in FIGS. 2 and 3, almost flat traction force and torque are obtained in the low rotation range. On the other hand, in the case of engine direct connection, as shown by the solid line, when the torque decreases in the rotation range lower than the maximum torque point and the rotation further decreases,
Due to the engine stop, the torque and traction force cannot be maintained. Therefore, the traction force and torque of the shaded portions in FIGS. 2 and 3 are superior to those in the conventional case.

The power transmission path in the case of the second forward high speed is as follows. By the engagement of the direct coupling clutch 12, the output torque of the engine 2 is transmitted from the input shaft 11 to the intermediate shaft 29. Ring gear fixed clutch 3 of the planetary gear unit 22
By the engagement of 2, the power is transmitted to the reduction gear 24 through the sun gear 28, the planet carrier 34, the ring gear 33 of the planetary gear device 21, and the planet carrier 23. Then, the large reduction gear 52 that meshes with the small reduction gear 24 is driven, and the output shaft 51 rotates.

In the power transmission path, if the reduction ratio ρ4 of the planetary gear device 22 is 1.64 and the reduction ratio ρ3 of the small reduction gear 24 to the large reduction gear 52 is 1.00, the total reduction ratio is ρ.
4 x ρ3 = 1.64.

[0015]

As described above, according to the present invention, since the low speed stage is driven by the hydraulic motor, the following effects can be obtained. (1) A high traction force can be obtained at very low speeds. (2) It is possible to arbitrarily change the power distribution to the working machine and the traveling device, and it is possible to effectively use the engine horsepower. At the high speed stage where the engine power is directly input, it is the same as the conventional transmission and the power distribution cannot be adjusted, but at the low speed stage where the power is input from the hydraulic motor, the amount of oil supplied to the hydraulic motor. The power distributed to the traveling device and the working machine can be increased or decreased by adjusting the. Therefore, when focusing on traveling, the power to be distributed to the traveling equipment is increased to reduce the power distribution to the work equipment, and when focusing on driving the working equipment, the power to be distributed to the traveling equipment is reduced. It is possible to increase the power distribution to the. (3) It becomes possible to run at a slow speed and operate the working machine without stopping the engine. (4) Since the high speed stage is mechanical drive directly connected to the engine,
Highly efficient driving is possible.

[Brief description of drawings]

FIG. 1 is a diagram showing a power transmission path of a wheeled vehicle transmission according to the present embodiment.

[FIG. 2] In the case of direct connection of engine and hydraulic motor,
It is a traction force diagram.

FIG. 3 is a diagram showing a correlation between an output torque of an engine and a hydraulic motor and a rotation speed.

FIG. 4 is a diagram showing an example of a power transmission path of a transmission for a wheeled vehicle according to a conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 transmission 2 engine 3 hydraulic motor 4 hydraulic pump 10 engine input part 11,41 input shaft 12,42 direct coupling clutch 20 planetary gear transmission part 21,22 planetary gear device 23,34 planet carrier 24,43 deceleration small gear 25 rotating clutch 27, 28 Sun gear 29 Intermediate shaft 33 Ring gear 40 Motor input section 44, 52 Reduction gear wheel 50 Output section 51 Output shaft

Claims (2)

[Claims] 1. An engine input unit that connects an input shaft on one side of a transmission to an output shaft of the engine, and inputs an output torque of the engine through the input shaft, and a hydraulic pump driven by the engine as a hydraulic power source. And an input shaft on the other side of the transmission, which is connected to the output shaft of the forward / reverse rotatable hydraulic motor, and a motor input unit for inputting the output torque of the hydraulic motor via the input shaft, and two sets of planetary gears. A transmission for a wheeled vehicle, comprising: a planetary gear speed changer including the device; and an output shaft including an output shaft and one reduction gear that is fixed to the output shaft. 2. The engine input unit includes a direct coupling clutch attached to the input shaft, and the motor input unit includes a reduction gear wheel that rotates by engagement of the direct coupling clutch attached to the input shaft, and the reduction gear unit. A reduction gear that meshes with the intermediate shaft connected to the direct coupling clutch of the engine input section,
A rotary clutch, two sets of sun gears of a planetary gear device, and a reduction gear large gear of the motor input unit are attached, and a planetary carrier of the planetary gear device on one side is attached to a reduction small gear rotated by engagement of the rotation clutch. And the planet carrier of the planetary gear device on the other side is connected to the ring gear of the planetary gear device on one side, and the reduction gear small gear that is rotated by the engagement of the rotary clutch is connected to the reduction gear large gear fixed to the output shaft. The transmission for a wheeled vehicle according to claim 1, wherein the transmission is engaged with each other.