JPH11268549A - Power transmission for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To resolve strength-related problem without changing parts when the strength-related problem is caused on the parts in the halfway of transmitting path of a power transmission. SOLUTION: In the power transmission of a vehicle for transmitting power from a first transmitting shaft 11 to a second transmitting shaft 17, to transmit the power to a third transmitting shaft 26 from the shaft 17 via a power transmitting means 25, a speed is increased from the shaft 11 to the shaft 17 to transmit the power with transmitting torque lowered, and this speed-increased part is adjusted after passing the means 25.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power transmission device for a vehicle, and is employed, for example, in a four-wheel drive tractor.

[0002]

2. Description of the Related Art Conventionally, in a four-wheel drive tractor, a first transmission gear is provided on a bevel pinion shaft for inputting power from an engine to a rear wheel differential, and a second transmission gear meshes with the first transmission gear. A transmission gear is provided on the front wheel power transmission shaft, and power is transmitted from the front wheel power transmission shaft to the front wheel differential, and power is transmitted from the front wheel differential to the left and right front wheels.

[0003]

In a four-wheel drive tractor, a certain class (size) is required to reduce the cost.
A lower-class tractor front wheel differential (smaller than the tractor) is adopted as the tractor front-wheel differential to reduce costs by sharing parts with the lower-class tractor. (The parts other than the front wheel differential of the front wheel power transmission mechanism from the bevel pinion shaft for inputting the power from the engine to the rear wheel differential to the front wheels are the same).

However, in this case, since the components of the lower class tractor are used for the upper class tractor, the strength of the front wheel differential device is insufficient, and it is not possible to use the components together. is there. Further, apart from the above problem, as a result of the power-up, there may be a problem with the strength of the front wheel differential device. In this case, measures to increase the strength, such as increasing the width of the gears, must be taken. .

[0005] In view of the above problems, the present invention solves the problem of the strength of a part of the power transmission device in the middle of the power transmission path without changing the part. The purpose is to do.

[0006]

The technical means taken by the present invention to achieve the above object is that the first transmission shaft is provided with a second transmission shaft.
And a power transmission device for transmitting power to the third transmission shaft from the second transmission shaft to the third transmission shaft via power transmission means. 2 to increase the power transmission to the transmission shaft, and adjust the increased speed after the power transmission means.
The transmission torque of the second transmission shaft is reduced.

Power is transmitted from the transmission shaft of a power transmission mechanism that transmits power from the engine to the rear wheels to the front wheel power transmission shaft, and power is transmitted from the front wheel power transmission shaft to the front wheels via the front wheel differential. In the power transmission device for a vehicle as described above, the power is transmitted from the power transmission shaft to the front wheel power transmission shaft at an increased speed, and the increased speed is adjusted after passing through the front wheel differential device. The transmission torque of the transmission shaft is reduced.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a traveling system power transmission device 1 of a tractor exemplified as a vehicle. The power transmission device 1 includes a rear wheel power transmission mechanism 4 that transmits rotational power from an engine E to a rear wheel 3, and an engine E And a front wheel power transmission mechanism 6 for transmitting rotational power from the vehicle to the front wheels 5.
Therefore, the tractor is a four-wheel drive tractor.

The rear wheel power transmission mechanism 4 has an input shaft 7 composed of a cylindrical shaft through which rotational power from the engine E is connected and disconnected via the clutch 2, and a front portion of the input shaft 7. Is provided with a selective gear type forward / reverse switching mechanism 8 for switching the rotation direction of the input shaft 7. A propulsion shaft 9 is provided in parallel with the input shaft 7.
A selection gear-type main transmission mechanism 10 that transmits rotational power from the input shaft 7 to the propulsion shaft 9 while changing the rotational speed in several stages is provided between the front part of the input shaft 7 and the rear part of the input shaft 7.

A bevel pinion shaft 11 (exemplified as a first transmission shaft and a transmission shaft according to claim 1) is disposed behind the propulsion shaft 9. The bevel pinion shaft 11 is Rotational power is transmitted from the propulsion shaft 9 by a selection gear type auxiliary transmission mechanism 12 capable of changing the rotation speed to two stages. A rear wheel differential (differential gear) 13 is provided behind the bevel pinion shaft 11, and rotational power is transmitted from the bevel pinion shaft 11 to left and right output shafts 14 via the rear wheel differential 13. You.

The rotational power transmitted to the output shaft 14 is further decelerated by a final reduction gear 15 comprising a planetary gear device and transmitted to the rear axle 16, whereby the rear wheel 3 is driven to rotate. It has become. Below the bevel pinion shaft 11, a front wheel power transmission mechanism 6 is provided.
A front wheel power transmission shaft 17 (exemplified as a second transmission shaft of claim 1), which is an input shaft, is arranged in parallel. Is transmitted (taken out).

The transmission means 18 includes a bevel pinion shaft 1
Transmission gear 19 provided on the front wheel power transmission shaft 1
7 and a second transmission gear 20 that meshes with the first transmission gear 19. The first transmission gear 19 and the second transmission gear 20 are composed of spur gears or the like.

A propulsion shaft 21 is provided in front of the front wheel power transmission shaft 17.
Rotational power is transmitted to the propulsion shaft 21 via a clutch 22 from the front wheel power transmission shaft 17 so as to be able to be connected and disconnected. A coupling 23 is provided at the front end side of the propulsion shaft 21.
A bevel pinion shaft 24 is connected by a front wheel differential device 25 (illustrated as a power transmission means of claim 1) is provided in front of the bevel pinion shaft 24. Left and right output shafts 2 (illustrated as the third transmission shaft of claim 1) from the pinion shaft 24
The rotation power is transmitted to 6.

At the outer end of the left and right output shafts 26, a third transmission gear 27 made of a bevel gear is provided.
The transmission gear 27 meshes with a fourth transmission gear 29 formed of a bevel gear provided above the king pin 28, and a fifth transmission gear 30 formed of a bevel gear is provided below the king pin 28. The rotational power transmitted to the king pin 28 is further reduced and transmitted to the front axle 32 from the fifth transmission gear 30 via the final reduction gear 31 composed of a planetary gear device, whereby the front wheel 5 is rotationally driven. It has become so.

In the above-described embodiment, the number of teeth of the first transmission gear 19 is set to 32T, the number of teeth of the second transmission gear 20 is set to 31T, and the transmission means 18 is provided with a speed increasing mechanism. Therefore, the power is transmitted from the bevel pinion shaft 11 to the front wheel power transmission shaft 17 at an increased speed. The number of teeth of the third transmission gear 27 is set to 18T, and the number of teeth of the fourth transmission gear 29 is set to 19T, so that power is transmitted from the output shaft 26 to the kingpin 28 by being reduced in speed. In this case, the power transmitted at the increased speed by the transmission means 18 is adjusted.

Therefore, in the above configuration,
The power transmission is performed at the same speed from the bevel pinion shaft 11 to the front wheel power transmission shaft 17 or the power is reduced and the power is transmitted from the bevel pinion shaft 11 to the front wheel power transmission shaft 17 at the same time. King pin 28 from shaft 26
The transmission torque of the front wheel power transmission shaft 17 in the present invention is smaller than that of the present invention in which the speed is increased and the power is transmitted to adjust the deceleration. Thus, the burden on the front wheel differential 25 is reduced.

Therefore, the front wheel differential 25 can be sufficiently used even if a tractor of the lower class is adopted, and the parts can be shared, and the inexpensive front wheel differential 25 can be used, and the cost can be reduced. Can be achieved. The above embodiment is an example of the present invention, and the speed increase ratio from the bevel pinion shaft 11 to the front wheel power transmission shaft 17 and the speed reduction ratio from the output shaft 26 to the kingpin 28 depend on other factors. For example, various designs are changed depending on the front wheel differential device used, the ratio between the front wheel diameter and the rear wheel diameter, and the like. Transmission means 1
The adjustment of the speed increase of 8 may be performed by other parts, for example, the bevel gear below the king pin 28, or the ratio between the front wheel diameter and the rear wheel diameter.

The concept of the present invention can be applied to the rear wheel power transmission mechanism, that is, when the power transmission means in the power transmission path of the power transmission device has a strength problem.

[0019]

According to the present invention, the first transmission shaft is connected to the second transmission shaft.
Power transmission device for transmitting power to the third power transmission shaft through the second power transmission shaft to the third power transmission shaft through the power transmission device. When there is, by increasing the speed from the first power transmission shaft to the second power transmission shaft to transmit the power, and adjusting the increased speed after passing through the power transmission means, Since the transmission torque of the second power transmission shaft is reduced, the strength problem can be solved without changing the power transmission means. Conversely, it can be said that there is no problem even if the strength of the power transmission means is reduced, and that the cost can be reduced.

Power is transmitted from the transmission shaft of the power transmission mechanism that transmits power from the engine to the rear wheels to the front wheel power transmission shaft, and the power is transmitted from the front wheel power transmission shaft to the front wheels via the front wheel differential. In such a vehicle power transmission device, by increasing the speed from the transmission shaft to the front wheel power transmission shaft to transmit the power, and adjusting the increased speed after passing through the front wheel differential device, Since the transmission torque of the front wheel power transmission shaft is reduced, there is no problem even if the strength of the front wheel differential is reduced. Therefore, for example, adopting the front wheel differential of the lower class tractor to the upper class tractor , Parts can be shared, and costs can be reduced.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a traveling system power transmission device of a four-wheel drive tractor.

[Explanation of symbols]

 Reference Signs List 3 rear wheel 4 rear wheel power transmission mechanism 11 bevel pinion shaft (first transmission shaft, transmission shaft) 17 front wheel power transmission shaft (second transmission shaft) 25 front wheel differential device (power transmission means) 26 output shaft E engine

Claims (2)

[Claims] 1. A vehicle in which power is transmitted from a first transmission shaft to a second transmission shaft, and power is transmitted from the second transmission shaft to a third transmission shaft via a power transmission means. In the power transmission device, the speed is increased from the first transmission shaft to the second transmission shaft to transmit power, and the increased speed is adjusted after passing through the power transmission means. Power transmission device for a vehicle. 2. Power is transmitted from a transmission shaft of a rear wheel power transmission mechanism for transmitting power from an engine to a rear wheel to a front wheel power transmission shaft, and power is transmitted from the front wheel power transmission shaft to a front wheel via a front wheel differential. In the vehicle power transmission device, the power is transmitted from the power transmission shaft to the front wheel power transmission shaft at an increased speed, and the increased speed is adjusted after passing through the front wheel differential device. A power transmission device for a vehicle, comprising: