JP2002052946A - Power transmission for tractor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten a longitudinal length of a machine body by compactly assembling a sub transmission and a front wheel accelerating device required for a traveling system of a tractor and a transmission mechanism required for a power taking out system in a transmission case. SOLUTION: A clutch 7 in the form of wet multiple discs is provided at a rear side of the transmission case 2 having a rear axle differential device 1, and a transmission mechanism for taking out normal rotations and reverse rotations with respect to a power taking out shaft 5 is provided at a front side thereof. The sub transmission for shifting a bevel pinion shat 29 in high and low two stages and the accelerating device for accelerating a front wheel transmitting shaft 62 are provided at a front side of the rear axel differential device 1.

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 tractor, and an object thereof is to shorten a longitudinal length of an airframe by compactly storing a gear mechanism and the like for a multi-speed transmission in a transmission case.

[0002]

2. Description of the Related Art In a tractor, a multi-stage transmission is provided in a transmission case. The transmission requires a so-called PTO transmission for a power take-off shaft for driving a working machine connected to the rear of the tractor as well as the traveling system. An on-off clutch is required, and was conventionally housed in a transmission case.

In recent years, a tractor is provided with a front wheel speed-increasing mechanism for increasing the rotation of the front wheels only during turning so that the body can be turned with a small turning radius during turning.

[0004]

As described above, conventionally, a multi-stage transmission, a front wheel speed increasing mechanism, and a clutch for turning on / off the power of the PTO system are provided in the transmission case. There are drawbacks that the length is long and that the structure inside the case is complicated and tends to win.

[0005]

An object of the present invention is to provide a device capable of shortening the front-rear length of a transmission case and simplifying the structure of a power transmission unit in the transmission case. The configuration was as follows.

That is, a power take-off transmission shaft 3, a counter shaft 4, and a power take-out shaft 5 are provided at the rear of the transmission case 2 having the rear axle differential 1, and a cylindrical shaft 6 is provided around the outer periphery of the power take-out transmission shaft 3. The power take-out transmission shaft 3 and the rear portion of the cylinder shaft 6 are provided so as to be able to be turned on and off by a wet multi-plate clutch 7 attached to the rear side of the transmission case 2 between the rear portion of the power take-off transmission shaft 3 and the cylinder shaft 6. 5, a speed change transmission mechanism for taking out forward and reverse rotation with respect to the power take-off shaft 5 is provided.
On the other hand, on the front side of the rear axle differential 1, there is provided an auxiliary transmission for transmitting the bevel pinion shaft 29 in two stages of high and low and a speed increasing device for increasing the speed of the front wheel transmission shaft 62. Power transmission device.

[0007]

In the transmission of the traveling system of the tractor, the rotational power shifted by the main transmission is further shifted by the auxiliary transmission, and transmitted from the bevel pinion shaft 29 to the rear axle differential 1 to drive the rear wheels.

When the vehicle is traveling straight, the front wheels and the rear wheels are set at substantially the same speed, and when turning, the speed of the front wheels is increased to approximately twice the speed of the rear wheels to turn the body. Transmission of power to the power take-off shaft 5 for driving the work machine is performed by turning on / off a clutch 7 attached to the rear of the transmission case.

When transmitting forward rotation power or reverse rotation power to a working machine connected to the rear of the machine, the speed change transmission mechanism of the power take-out section is appropriately operated to switch the rotation direction and change the speed.

[0010]

Referring to FIG. 3, the tractor body has an engine E at the front, and a clutch housing 16 and a front and rear transmission case 2 are connected to the engine E at the rear. An axle bracket 17 is provided at a front portion of the engine E, and a front axle housing 19 with a front wheel 18 is supported at a lower portion. Rear mission cage
A rear axle housing 21 with a rear wheel 20 axle is integrally provided on both left and right sides of the
2 is equipped with a hydraulic cylinder that moves up and down hydraulically.
And 23.

On the vehicle body, a cockpit 25 is provided between left and right fenders 24, and a steering handle 26 is provided in front of the cockpit 25. 27 is a main transmission lever for operating the main transmission, and 28 is an auxiliary transmission lever for operating the auxiliary transmission.
The transmission mechanism includes a main clutch,
And a reverse clutch are provided.
A main transmission and an auxiliary transmission are provided therein, and the rotational power decelerated by these transmissions is transmitted to the traveling bevel pinion shaft 29 of the rear transmission case 2. A transmission shaft 30 of a power take-off transmission system is provided at the center of the transmission clutches of the main transmission and the auxiliary transmission, and a transmission shaft 32 on which the main transmission clutch and the auxiliary transmission clutch 31 are arranged is rotatable. Is provided.

The sub-transmission clutch 31 switches between the high-speed gear H and the low-speed gear L on the transmission shaft 32 to which the main transmission is transmitted, so that the gear 3 meshes with these gears H and L.
The bevel pinion shaft 29 in which the gears 3 and 34 are integrated is speed-changed. The transmission of the bevel pinion shaft 29 causes the transmission of the axle 35 to the rear wheel 20 via the rear axle differential 1 in the rear transmission case 2, and the transmission from the gear 34 of the bevel pinion shaft 29. A front wheel transmission shaft 62 that transmits power to the front wheels 18 via the speed clutches 36 and 37 is interlocked. The speed increasing clutches 36 and 37 connect the front wheels 18 to the rear wheels 20.
It is possible to switch between a constant-speed clutch 36 that transmits at substantially the same speed as the above, and a speed increasing clutch 37 that increases the speed to approximately twice the speed.

At the rear end of the transmission shaft 30 of the power take-out system,
A power take-off transmission shaft 3 in a rear transmission case 2 is connected, and a rear portion of the transmission shaft 3 is connected to a rear wall 3 of the transmission case 2.
8 and the rear end is projected. Reference numeral 39 denotes a partition wall provided on the rear side of the differential device 1, and the transmission shaft 3 passes through a bearing hole of the partition wall 39. Further, a switching clutch 40 is provided between the front end of the transmission shaft 3 and the rear end of the transmission shaft 30 and the low-speed gear L. When the switching clutch 40 is shifted to the front side, the low-speed gear L A ground PT transmitting to the transmission shaft 3 and simultaneously transmitting to the gear 34 to transmit the traveling transmission and the power take-off shaft transmission in a fixed relation.
When the switching clutch 40 is shifted to the rear side, the transmission is connected from the transmission shaft 30 to the transmission shaft 3 so that the power is transmitted regardless of the traveling speed. The transmission form of the PTO may be used.

A transmission 41 for the power take-off shaft 5 supports a rotatable cylindrical shaft 6 around bearings 42 and 43 on the outer periphery of the transmission shaft 3 between a partition wall 39 and a rear wall 38. , A power take-out shaft 5, a counter shaft 4, a back counter shaft, and the like, and a gear shift is performed between these shafts 6, 5, 4, and the like. The front and rear gears 14 and 15 and the transmission clutch 44 between them are arranged on the outer periphery of the cylinder shaft 6, and the transmission clutch 44 is switched to the front gear 14 side so that the gear 14 and the cylinder shaft 6 are switched. Can be integrally rotated, and by switching to the rear gear 15 side, the gear 15
And the cylindrical shaft 6 can be integrally rotated. The gears 10 and 11 of the spline fitting are integrally formed on the counter shaft 4 as a two-stage gear. When the gear 10 is moved to the front side, the gear 10 can mesh with the gear 14 of the two-stage gear, and when moved to the rear side, the gear 10 11 can mesh with the reverse gear 45. This reverse gear 45
Is always in mesh with the gear 15. Also, power take-out shaft 5
The gears 12 and 13 fitted with the splines above are always in mesh with the respective gears 14 and 15 on the cylindrical shaft 6 at fixed positions.

The front ends of the cylinder shaft 6 and the counter shaft 4 are
It is located on the front side of the partition wall 39 and is always meshed with the gears 8 and 9. Accordingly, when the cylinder shaft 6 is rotated from the transmission shaft 3 via the clutch 7, the gear 10 meshes with the gear 14 to obtain a forward rotation, and when the transmission clutch 44 is set to the neutral N, the transmission is The first forward speed is obtained via the cylinder shaft 6 → gear 8 → gear 9 → counter shaft 4 → gear 10 → gear 14 → gear 12 → power take-off shaft 5. When the gear 10 is disengaged from the gear 14 and the transmission clutch 44 is shifted toward the gear 15 from this state, the cylinder shaft 6 → the gear 15 → the gear 13 →
The second forward speed is obtained via the power take-off shaft 5. When the transmission clutch 44 is shifted from this state to the gear 14, the third forward speed is obtained via the cylinder shaft 6, the gear 14, the gear 12, and the power take-off shaft 5.

When the power take-off shaft 5 is transmitted in the reverse direction, the gear 11 is engaged with the reverse rotation gear 45, and the transmission clutch 44 is set at the neutral N position. The reverse rotation R is as follows: cylinder shaft 6 → gear 8 → gear 9 → counter shaft 4 → gear 11 → reverse rotation gear 45 → gear 15
→ gear 13 → power take-off shaft 5. The clutch 7 for transmitting the power from the transmission shaft 3 to the cylindrical shaft 6 is provided inside a clutch case 46 that can be attached to and detached from the rear surface of the rear wall 38, and has a wet multi-plate configuration. The clutch 7 is turned on and off by hydraulic pressure from a hydraulic circuit 47, and a piston 49 for pressing a pressure plate is fitted to a cylinder portion in a clutch coupling 48. A boss portion 50 of the clutch coupling 48 can be integrally rotated with a rear end of the cylindrical shaft 6 by being fitted with a spline, and is supported by a bearing 43 with respect to the rear wall 38.

The bearing 43 is integrally formed with the cylindrical shaft 6 together with the bearing 42 and the like, and can be fitted into or removed from the rear wall 38 and the bearing hole of the partition wall 39 from the rear side. The rear surface of the bearing 43 is a clutch case. 46 front end and rear wall 3
It is stopped by the ring plate 51 sandwiched between the eight surfaces. 5
Reference numeral 2 denotes a clutch core facing the shaft center side of the clutch coupling 48, which is spline-fitted to the rear end of the transmission shaft 3 and integrally rotates. A wet multi-plate clutch disk 53 is provided between the clutch coupling 48 and the core 52.

The clutch case 46 is fitted to the power take-out shaft 5 projecting rearward from the rear wall 38, and a cap 54 for covering the protruding portion of the power take-out shaft 5 is made detachable. A rotation sensor 55 capable of detecting the number of rotations of the power take-off shaft 5 is attached. As described above, in the speed change transmission mechanism for transmitting the power take-out shaft 5 from the power take-out transmission shaft 3 in the transmission case 2, the clutch 7 transmitted from the power take-out transmission shaft 3 to the counter shaft 4 uses this transmission case. The clutch 7 is attached to the rear outside of the rear wall 38 of the clutch 2.
Gears 6 and 9 are disposed on the front side of the partition wall 39, that is, on the side of the rear axle differential 1, and the cylindrical shaft 6 connecting them is provided with a double shaft on the outer peripheral portion of the power take-off transmission shaft 3. Since gears 14, 15 and the like for speed change transmission are arranged on the outer periphery of the cylindrical shaft 6, the front-rear space between the partition wall 39 and the rear wall 38, that is, the rear axle The length of the transmission case 2 on the rear side from the differential gear 1 can be made shorter, and the internal transmission mechanism is made simple with a configuration mainly composed of a transmission shaft and gears, and the number of gear stages is reduced. Many settings can be made.

In FIG. 2, the point different from the above example is that the gear 14 and the gear 15 are integrated with the gear shaft 56 and rotatably provided on the outer periphery of the cylindrical shaft 6 to form a triple shaft. The direct transmission from the cylinder shaft 6 to the gear shaft 56 is turned on and off by a shift operation of the transmission clutch 57 inside the partition wall 39 between the front end portion with the gear shaft 56.

The gear 10 on the counter shaft 4 is a single-stage gear and can be meshed with the gear 14 and the reverse gear 45 by switching. On the power take-off shaft 5, a speed change clutch 58 that switches between the gears 12 and 13 is provided. When the clutch 7 is engaged, the power take-off transmission shaft 3
Is transmitted, the first forward speed is established by engaging the gear 10 with the gear 14, disengaging the transmission clutch 57 from the gear shaft 56, and shifting the transmission gear 58 to the gear 13 side. Gear 8 → Gear 9 → Counter shaft 4 → Gear 10
→ gear 14 → gear 13 → transmitted via the power take-off shaft 5. In the second speed, the transmission clutch 58 is shifted from this state to the first gear.
By shifting to the second side, the gear 14 → the gear 12 →
Power is transmitted through the power take-off shaft 5.

The first reverse speed and the second reverse speed are set at the first reverse speed from the gear 10 by engaging the gear 10 with the reverse rotation gear 45 in the first and second speeds. By shifting the transmission clutch 58 to the gear 13 side,
The gear 10 passes through the reverse gear 45 → the gear 15 → the gear 13 → the power take-out shaft 5. The second reverse speed is changed from the gear 10 to the reverse gear 45 by shifting the transmission clutch 58 to the gear 12 side.
→ gear 15 → gear 12 → power take-off shaft 5.

The third forward speed and the fourth forward speed are achieved by shifting the transmission clutch 57 toward the gear shaft 56, directly transmitting the gear shaft 56, and shifting the transmission clutch 58.
The third speed is from cylinder shaft 6 → gear shaft 56 → gear 15 → gear 13 →
It passes through the power take-off shaft 5. The fourth speed passes through this gear shaft 56 → gear 14 → gear 12 → power take-off shaft 5. 59, 6
Numeral 0 denotes a speed increasing gear of the speed increasing clutch 37, which is integrated with the gear shaft 61.

[0023]

According to the present invention, a power take-off transmission shaft 3, a counter shaft 4, and a power take-out shaft 5 are provided at the rear of a transmission case 2 having a rear axle differential 1, and the power take-off transmission shaft 3 is provided.
A cylinder shaft 6 is provided on the outer periphery of the power take-off transmission shaft 3 and a rear portion between the cylinder shaft 6 and a power transmission / reception can be provided by a wet-type multi-plate clutch 7 attached to the rear side of the transmission case 2 so as to be able to move in and out. A speed change transmission mechanism is provided between the cylindrical shaft 6 and the power take-off shaft 5 to take out forward and reverse rotations with respect to the power take-out shaft 5, while a bevel pinion shaft is provided on the front side of the rear axle differential 1. 29 is a power transmission device for a tractor, which is provided with an auxiliary transmission device for transmitting the transmission in two stages of high and low and a speed increasing device for increasing the speed of the front wheel transmission shaft 62.
Auxiliary transmissions and front wheel gears for the traveling system required for the tractor,
Further, the speed change transmission mechanism of the power take-out portion for driving the working machine can be compactly incorporated in the transmission case, and the transmission case is not made unnecessarily long.

[Brief description of the drawings]

FIG. 1 is a vertical sectional side view of a part of a tractor transmission mechanism.

FIG. 2 is a vertical sectional side view showing a partly different embodiment.

FIG. 3 is a side view of the tractor.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 rear axle differential 2 transmission case 3 power take-off transmission shaft 4 counter shaft 5 power take-out shaft 6 cylinder shaft 7 clutch 8 gear 9 gear 10 gear 11 gear 12 gear 13 gear 14 gear 15 gear

 ──────────────────────────────────────────────────続 き Continued on front page F term (reference) 2B041 AA02 AB03 AC07 EB07 EB12 3D039 AA03 AA04 AA05 AB12 AC24 AC37 AC40 AC65 AC70 AC77 AD11 AD23 AD36 AD54 3D043 AA06 AB12 BA06 BB01 BC03 BC05 BC09 BC11 BC16 BD03 BE01 EA33 EA18 EA18 EA37 EA38 EA42 EB01 EB06 EB12 EB14 EC01 EC03

Claims (1)

[Claims] 1. A power take-off transmission shaft 3, a counter shaft 4, and a power take-out shaft 5 are provided at a rear portion of a transmission case 2 having a rear axle differential 1, and a cylindrical shaft 6 is provided around an outer periphery of the power take-out transmission shaft 3. The power take-out transmission shaft 3 and the rear portion of the cylinder shaft 6 are provided so as to be able to be turned on and off by a wet multi-plate clutch 7 attached to the rear side of the transmission case 2 between the rear portion of the power take-off transmission shaft 3 and the cylinder shaft 6. 5, a transmission mechanism for taking out forward and reverse rotations with respect to the power take-off shaft 5 is provided.
A bevel pinion shaft 29 is provided in front of the rear axle differential 1.
Transmission and front wheel transmission shaft 62 for transmitting gears in two stages of high and low
A power transmission device for a tractor, comprising a speed increasing device for increasing the speed of the tractor.