JP2021095954A - Working vehicle - Google Patents

Abstract

To prevent a drag of a brake, in a working vehicle in which a planetary reduction mechanism for reducing the power of an output shaft, and transmitting it to an axle is arranged over the output shaft and the axle of a wheel differential mechanism, and which has the brake having a friction plate locked to a region between a differential case and the planetary reduction mechanism of the wheel differential mechanism out of the output shaft.SOLUTION: A working vehicle comprises a support member 91 for supporting an output shaft 17a between a differential case 81 and a planetary reduction mechanism 83. The support member 91 is constituted so as to be relatively immovably engaged with the output shaft 17a in a direction along an axial core of the output shaft 17a.SELECTED DRAWING: Figure 7

Description

The present invention relates to a work vehicle.

The work vehicle is provided with a wheel differential mechanism, an axle located on the lateral outer side of the vehicle body of the wheel differential mechanism, and an output shaft and an axle of the wheel differential mechanism to reduce the power of the output shaft. It has a planetary deceleration mechanism that transmits to the axle and a friction plate that is locked to the part of the output shaft between the differential case and the planetary deceleration mechanism in the wheel differential mechanism, and rubs against the axle via the output shaft. Some are equipped with a brake that applies braking force.

As a work vehicle of this type, for example, there is a tractor shown in Patent Document 1. The tractor shown in Patent Document 1 is provided with a rear wheel differential mechanism as a wheel differential mechanism, and is provided with a side brake as a brake.

Japanese Unexamined Patent Publication No. 10-203185

In the above-mentioned work vehicle, generally, the side gear of the wheel differential mechanism and the output shaft are interlocked and connected by spline engagement, and the rotating member of the planetary deceleration mechanism, for example, the sun gear and the output shaft are interlocked and connected by spline engagement. Therefore, the output shaft is in the direction along the axis of the output shaft with respect to the wheel differential mechanism and the planetary deceleration mechanism due to the operating force acting on the friction plate when the brake is operated on. If the brakes are displaced, the friction plate will move with the output shaft and the brake will be in a dragged state, resulting in power loss in driving the traveling wheels.

The present invention provides a work vehicle capable of preventing the drag of a brake.

The work vehicle according to the present invention
The wheel differential mechanism, an axle located on the lateral outer side of the vehicle body of the wheel differential mechanism, and an output shaft and the axle of the wheel differential mechanism are provided to reduce the power of the output shaft. It has a planetary deceleration mechanism that transmits to the axle and a friction plate that is locked to a portion of the output shaft between the differential case and the planetary deceleration mechanism in the wheel differential mechanism, via the output shaft. A brake that applies a friction braking force to the axle and a support member that supports the output shaft between the differential case and the planetary deceleration mechanism are provided, and the support member is provided with respect to the output shaft. It is configured to engage with the output shaft in a direction along the axis of the output shaft so as to be relatively immovable.

According to this configuration, even if an operating force for shifting the output shaft is generated, the output shaft is firmly supported by the support member against the operating force so as not to shift, so that the drag of the brake can be prevented. Further, when a configuration is adopted in which the output shaft is provided with a contact portion that abuts on the end of the axle and is received and supported to prevent the output shaft from shifting, the axle is located between the end of the axle and the contact portion. And friction is generated due to the rotation of the output shaft, and it is possible to prevent the brake from being dragged while avoiding the occurrence of this friction.

In the present invention
It is preferable that the support member supports a portion of the output shaft between the friction plate and the planetary deceleration mechanism.

According to this configuration, the part of the output shaft near the planetary deceleration mechanism side is supported by the support member, so that power transmission from the output shaft to the planetary deceleration mechanism is performed without center deviation of the output shaft. The output shaft can be supported by a support member.

In the present invention
The support member is preferably a bearing that fits outside the output shaft.

According to this configuration, since the output shaft is supported so as not to shift while allowing smooth rotation of the output shaft, it is possible to more reliably prevent power loss in wheel drive.

In the present invention
The brake is configured to press the friction plate in a direction along the axis of the output shaft and press contact with the friction plate receiving portion.
It is preferable that the bearing is supported by the friction plate receiving portion.

According to this configuration, since the friction plate receiving portion is used for the bearing support member, the bearing support structure can be made simple.

It is a left side view which shows the whole tractor. It is a diagram which shows the power transmission structure. It is a vertical sectional side view of a power take-out device. It is a diagram which shows the power take-out device. It is a right side view which shows the operation part for shifting. It is a rear view which shows the operation part for shifting. It is sectional drawing which shows the drive part of a rear wheel.

Hereinafter, embodiments that are an example of the present invention will be described with reference to the drawings.
In the following description, with respect to the traveling vehicle body of the tractor (an example of the "working machine"), the direction of the arrow F shown in FIG. 1 is the "front of the vehicle body", the direction of the arrow B is the "rear of the vehicle body", and the direction of the arrow U. Is "upper body", the direction of arrow D is "lower body", the direction on the front side of the paper is "left side of the car body", and the direction on the back side of the paper is "right side of the car body".

[Overall configuration of the tractor]
As shown in FIG. 1, the tractor includes a traveling vehicle body 3 equipped with a pair of left and right front wheels 1 steerable and driveable, and a pair of left and right rear wheels 2 driveable. A driving portion 5 having an engine 4 is formed at the front portion of the traveling vehicle body 3. At the rear of the traveling vehicle body 3, a driving unit 8 having a driver's seat 6 and a steering wheel 7 for steering and operating the front wheels 1 is formed. The driver unit 8 is provided with a cabin 9 that covers the boarding space. A link mechanism 10 for connecting various work devices (not shown) such as a rotary tiller to the rear part of the traveling vehicle body 3 so as to be able to move up and down, and a work device connected by taking out power from the engine 4 by a power take-out shaft 41 A power extraction device 40 that outputs power toward (drive target device) is provided. The body frame of the traveling vehicle body 3 has a front portion connected to the rear parts of the engine 4 and the engine 4, a mission case 11 supporting the rear wheels 2, and a front wheel support frame 12 connected to the lower part of the engine 4 to support the front wheels 1. It is composed of.

[Structure of power transmission]
The power of the engine 4 is transmitted to the front wheels 1, the rear wheels 2, and the power take-out shaft 41 based on the power transmission structure shown in FIG.

That is, the power of the engine output shaft 4a of the engine 4 is transmitted to the mission input shaft 11a of the mission case 11. The power of the transmission input shaft 11a is input to the forward / backward switching device 13 and converted into forward power and reverse power. The converted forward power and reverse power are input to the main transmission 14 capable of shifting in 8 speeds to cause a main shift, and the main shift power is input to the creep transmission 15 capable of shifting in 2 speeds. The output of the creep transmission 15 is input to the auxiliary transmission 16 capable of three-speed shifting, and the auxiliary transmission is performed. The sub-shifted power is input to the rear wheel differential mechanism 17 and transmitted from the left and right output shafts 17a of the rear wheel differential mechanism 17 to the left and right rear wheels 2. The power from the auxiliary transmission 16 is transmitted to the front wheel transmission 20 via the input shaft 17b of the rear wheel differential mechanism 17, is transmitted from the front wheel transmission 20 to the front wheel differential mechanism 21, and is transmitted from the front wheel differential mechanism 21 to the left and right. Is transmitted to the front wheel 1 of. The front wheel transmission 20 is configured to be switchable between a cut state, a constant speed transmission state, and a speed increase transmission state. When the front wheel transmission 20 is switched to the off state, the output toward the front wheel differential mechanism 21 is cut off, and the tractor is in a two-wheel drive state in which only the rear wheel 2 of the front wheel 1 and the rear wheel 2 is driven. become. When the front wheel transmission 20 is switched to the constant speed transmission state, the power from the input shaft 17b is output toward the front wheel differential mechanism 21 in the constant speed state, and the tractor is the average peripheral speed of the left and right front wheels 1. The front wheels 1 and the rear wheels 2 are driven in a four-wheel drive state in which the average peripheral speeds of the left and right rear wheels 2 are substantially equal to each other. When the front wheel transmission 20 is switched to the speed-increasing transmission state, the power from the input shaft 17b is increased and output toward the front wheel differential mechanism 21, and the tractor has an average peripheral speed of the left and right front wheels 1. The front wheels 1 and the rear wheels 2 are driven in a four-wheel drive state in a state where the average peripheral speeds of the left and right rear wheels 2 are faster than the average peripheral speed.

The power of the mission input shaft 11a is transmitted via the front rotating shaft 22 in which the front end is connected to the rear end of the mission input shaft 11a and the rear rotating shaft 23 in which the front end is connected to the rear end of the front rotating shaft 22. It is transmitted to the work clutch 24, and is transmitted from the work clutch 24 to the power extraction device 40.

[Structure of power take-out device]
As shown in FIG. 1, the power extraction device 40 is provided at the rear portion of the traveling vehicle body 3. As shown in FIG. 3, the power take-out device 40 includes a power take-out case 42 formed at the rear portion of the mission case 11. The power take-out case 42 is composed of a mission case 11 and a gear case 42a detachably attached to the rear wall portion 11b with the opening formed in the rear wall portion 11b of the mission case 11 closed. The power take-out shaft 41 is projected backward from the upper and lower intermediate portions of the gear case 42a. In FIG. 3, the power take-out shaft 41 is covered with a cover 41a that can be attached to and detached from the gear case 42a.

As shown in FIGS. 3 and 4, the input shaft 43 is provided above the internal space S of the power take-out case 42 in a state of extending in the front-rear direction of the vehicle body. The input shaft 43 is rotatably supported by the gear case 42a and the support wall portion 44 located in front of the gear case 42a. The support wall portion 44 is connected to the gear case 42a via connecting rod portions (not shown) extending rearward from a plurality of peripheral portions of the support wall portion 44, and is supported by the gear case 42a. The front portion of the input shaft 43 is interlocked and connected to the output member 24a of the work clutch 24. The power of the mission input shaft 11a, that is, the power of the engine 4 is transmitted to the input shaft 43.

Below the input shaft 43, an output shaft 45 extending in the front-rear direction of the vehicle body in parallel with the input shaft 43 is provided. The output shaft 45 is rotatably supported by the gear case 42a and the support wall portion 44. The output shaft 45 is interlocked with the power take-out shaft 41 by spline engagement between the rear portion of the output shaft 45 and the front portion of the power take-out shaft 41. The power of the output shaft 45 can be taken out by the power take-out shaft 41.

A first gear train 46 is provided across the front portion of the input shaft 43 and the front portion of the output shaft 45. The first gear train 46 is rotatably supported by the output shaft 45 in a state of being meshed with the first input shaft gear 46A and the first input shaft gear 46A which are rotatably supported by the input shaft 43. It has only two gears of one output shaft gear 46B. Behind the first gear train 46, a second gear train 47 is provided across the input shaft 43 and the output shaft 45. The second gear train 47 is rotatably supported by the output shaft 45 in a state of being meshed with the second input shaft gear 47A and the second input shaft gear 47A which are rotatably supported by the input shaft 43. It has only two gears of the two output shaft gears 47B. The first output shaft gear 46B is supported by the output shaft 45 via a tapered roller bearing 48 interposed between the boss portion of the first output shaft gear 46B and the output shaft 45. The second output shaft gear 47B is supported by the output shaft 45 via a tapered roller bearing 48 interposed between the boss portion of the second output shaft gear 47B and the output shaft 45. The taper roller bearing 48 of the first output shaft gear 46B and the taper roller bearing 48 of the second output shaft gear 47B are provided with two rows of rollers facing outward.

The outer diameter of the second input shaft gear 47A is larger than the outer diameter of the first input shaft gear 46A. The outer diameter of the first output shaft gear 46B is larger than the outer diameter of the first input shaft gear 46A. The outer diameter of the second output shaft gear 47B is larger than the outer diameter of the second input shaft gear 47A. The outer diameter of the second output shaft gear 47B is smaller than the outer diameter of the first output shaft gear 46B. The first speed transmission ratio Z1 of the first gear train 46 and the second speed transmission ratio Z2 of the second gear train 47 are different.

As shown in FIGS. 3 and 4, the input shaft sleeve 50 is relatively non-rotatably and slidably supported by the input shaft 43 between the first input shaft gear 46A and the second input shaft gear 47A. When the input shaft sleeve 50 is slid toward the first input shaft gear side, the input shaft sleeve 50 engages with the locking portion 46c formed on the side portion of the first input shaft gear 46A to engage the first input shaft gear 46A with the input shaft. Interlocked with 43. When the input shaft sleeve 50 is slid toward the second input shaft gear side, the input shaft sleeve 50 engages with the locking portion 47c formed on the side portion of the second input shaft gear 47A to engage the second input shaft gear 47A with the input shaft. Interlocked with 43.

As shown in FIGS. 3, 5 and 6, a first shift fork 51 that engages with the input shaft sleeve 50, a first speed change arm 52 that is swingably provided outside the power take-out case 42, and the like are used. The first operation unit 53 is configured so that the first input shaft gear 46A and the second input shaft gear 47A are selectively interlocked and connected to the input shaft 43. The first shift fork 51 and the first transmission arm 52 are a slide shaft 54 that slides the first shift fork 51, a swing arm 55 whose free end is engaged with the slide shaft 54, a swing arm 55, and a first swing arm 55. They are interlocked and connected via a rotary support shaft 56 that swingably supports the transmission arm 52.

In the first operation unit 53, the first shift arm 52 is oscillated with the axis of the rotary support shaft 56 as the oscillating fulcrum, so that the first shift fork 51 is oscillated along the axis of the input shaft 43. The first shift fork 51 engages the input shaft sleeve 50 with the first input shaft gear 46A to interlock the first input shaft gear 46A with the input shaft 43, or the first shift fork 51 inputs. The shaft sleeve 50 is engaged with the second input shaft gear 47A, and the second input shaft gear 47A is interlocked with the input shaft 43.

As shown in FIGS. 3 and 4, the output shaft sleeve 60 is relatively non-rotatably and slidably supported on the output shaft 45 between the first output shaft gear 46B and the second output shaft gear 47B. When the output shaft sleeve 60 is slid toward the first output shaft gear side, the output shaft sleeve 60 engages with the locking portion 46d formed on the side portion of the first output shaft gear 46B to rotate the first output shaft gear 46B to the output shaft. Interlocked with 45. When the output shaft sleeve 60 is slid toward the second output shaft gear side, the output shaft sleeve 60 engages with the locking portion 47d formed on the side portion of the second output shaft gear 47B to move the second output shaft gear 47B to the output shaft. Interlocked with 45.

As shown in FIGS. 3, 5 and 6, a second shift fork 61 engaged with the output shaft sleeve 60, a second speed change arm 62 provided on the outside of the power take-out case 42 so as to be swingable, and the like are used. The second operation unit 63 is configured so that the first output shaft gear 46B and the second output shaft gear 47B are selectively interlocked and connected to the output shaft 45. The second shift fork 61 and the second transmission arm 62 are a slide shaft 64 that slides the second shift fork 61, a swing arm 65 whose free end is engaged with the slide shaft 64, a swing arm 65, and a second. They are interlocked and connected via a rotary support shaft 66 that swingably supports the transmission arm 62.

In the second operation unit 63, the second shift arm 62 is oscillated with the axis of the rotary support shaft 66 as the swing fulcrum, so that the second shift fork 61 is oriented along the axis of the output shaft 45. The second shift fork 61 engages the output shaft sleeve 59 with the first output shaft gear 46B to link the first output shaft gear 46B to the output shaft 45, or the second shift fork 61 outputs. The shaft sleeve 60 is engaged with the second output shaft gear 47B, and the second output shaft gear 47B is interlocked and connected to the output shaft 45.

As shown in FIG. 5, the first operation unit 53 and the second operation unit 63 are operated by one speed change operating tool 67 linked to the first speed change arm 52 and the second speed change arm 62. That is, the speed change operating tool 67 is linked to the first speed change arm 52 to enable the swing operation of the first speed change arm 52, and is linked to the second speed change arm 62 to swing the second speed change arm 62. It is configured so that it can be switched to a state where it can be operated.

As shown in FIGS. 3 and 4, a relay transmission shaft 70 extending in the front-rear direction of the vehicle body in parallel with the output shaft 45 is provided below the output shaft 45. The relay transmission shaft 70 is rotatably supported by the gear case 42a and the support wall portion 44. As shown in FIG. 6, the input shaft 43, the output shaft 45, and the relay transmission shaft 70 are located on a straight line in the vertical direction of the machine body in the front-rear direction view of the vehicle body. As shown in FIGS. 3 and 4, the relay transmission shaft 70 is interlocked with the first output shaft gear 46B by the first relay transmission gear mechanism 71 provided at the front portion of the relay transmission shaft 70, and the relay transmission shaft 70 is connected to the first output shaft gear 46B. It is interlocked with the second output shaft gear 47B by a second relay transmission gear mechanism 72 provided at the rear portion. The first gear train 46 and the first relay transmission gear mechanism 71 are located on the side surface of the vehicle body on a straight line in the vertical direction of the machine body passing through the axis of the input shaft 43, the axis of the output shaft 45, and the axis of the relay transmission shaft 70. It is provided in a row. The second gear row 47 and the second relay transmission gear mechanism 72 are located on the side surface of the vehicle body on a straight line in the vertical direction of the machine body passing through the axis of the input shaft 43, the axis of the output shaft 45, and the axis of the relay transmission shaft 70. It is provided in a row. The first relay transmission gear mechanism 71 is composed of a first relay transmission gear 71 that is supported by the relay transmission shaft 70 so as not to rotate relative to the relay transmission shaft 70 in a state of being meshed with the first output shaft gear 46B. The second relay transmission gear mechanism 72 is composed of a second relay transmission gear 72 that is supported by the relay transmission shaft 70 so as not to rotate relative to the relay transmission shaft 70 in a state of being meshed with the second output shaft gear 47B.

The outer diameter of the first relay transmission gear 71 is smaller than the outer diameter of the first output shaft gear 46B. The outer diameter of the second relay transmission gear 72 is smaller than the outer diameter of the second output shaft gear 47B. The outer diameter of the second relay transmission gear 72 is larger than the outer diameter of the first relay transmission gear 71. The first relay speed transmission ratio Y1 of the first relay transmission gear mechanism 71 and the second relay speed transmission ratio Y2 of the second relay transmission gear mechanism 72 are different.

The power of the input shaft 43 is supplied by the first gear row 46, the second gear row 47, the input shaft sleeve 50, the output shaft sleeve 60, the relay transmission shaft 70, the first relay transmission gear mechanism 71, and the second relay transmission gear mechanism 72. A gear transmission mechanism M is configured in which the rotation speed is changed in four stages to different transmission powers and transmitted to the output shaft 45. In the power take-out device 40, the first operation unit 53 alternately connects the first input shaft gear 46A and the second input shaft gear 47A to the input shaft 43, and the second operation unit 63 connects the first output shaft. By selectively interlocking the gear 46B and the second output shaft gear 47B with the output shaft 45, the gear shift mechanism M is in the first shift state, the second shift state, the third shift state, and the fourth shift state. The rotation speed of the power take-out shaft 41 is changed to 4 steps.

That is, the first input shaft gear 46A is interlocked and connected to the input shaft 43 by the operation of the input shaft sleeve 50 by the first operation unit 53, and the first output shaft gear 46B is operated by the operation of the output shaft sleeve 60 by the second operation unit 63. When interlocked with the output shaft 45, the gear shifting mechanism M is in the first shifting state. The gear shifting mechanism M in the first shifting state transmits the power of the input shaft 43 to the output shaft 45 via the first gear train 46, and the power taking-out shaft 41 has a rotation speed set by the first shifting state. Driven.

The second input shaft gear 47A is interlocked with the input shaft 43 by the operation of the input shaft sleeve 50 by the first operation unit 53, and the second output shaft gear 47B is connected to the output shaft by the operation of the output shaft sleeve 60 by the second operation unit 63. When interlocked with 45, the gear shifting mechanism M is in the second shifting state. The gear shifting mechanism M in the second shifting state transmits the power of the input shaft 43 to the output shaft 45 via the second gear row 47, and the power taking-out shaft 41 has a rotation speed set by the second shifting state. Driven.

The first input shaft gear 46A is interlocked with the input shaft 43 by the operation of the input shaft sleeve 50 by the first operation unit 53, and the second output shaft gear 47B is connected to the output shaft by the operation of the output shaft sleeve 60 by the second operation unit 63. When interlocked with 45, the gear shifting mechanism M is in the third shifting state. The gear transmission mechanism M in the third shift state uses the power of the input shaft 43 as the power of the first gear train 46, the first relay transmission gear mechanism 71, the relay transmission shaft 70, the second relay transmission gear mechanism 72, and the second output shaft. It is transmitted to the output shaft 45 via the gear 47B, and the power take-out shaft 41 is driven at the rotation speed set by the third speed change state. At this time, the first output shaft gear 46B is supported by the output shaft 45 while rotating relative to the output shaft 45 on which the drive load of the power take-out shaft 41 is applied, but is supported via the taper roller bearing 48. , Power is transmitted while rotating smoothly.

The second input shaft gear 47A is interlocked with the input shaft 43 by the operation of the input shaft sleeve 50 by the first operation unit 53, and the first output shaft gear 46B is connected to the output shaft by the operation of the output shaft sleeve 60 by the second operation unit 63. When interlocked with 45, the gear shifting mechanism M is in the fourth shifting state. The gear transmission mechanism M in the fourth shift state uses the power of the input shaft 43 as the power of the second gear train 47, the second relay transmission gear mechanism 72, the relay transmission shaft 70, the first relay transmission gear mechanism 71, and the first output shaft. It is transmitted to the output shaft 45 via the gear 46B, and the power take-out shaft 41 is driven at the rotation speed set by the fourth shift state. At this time, the second output shaft gear 47B is supported by the output shaft 45 while rotating relative to the output shaft 45 on which the drive load of the power take-out shaft 41 is applied, but is supported via the taper roller bearing 48. , Power is transmitted while rotating smoothly.

[Rear wheel drive structure]
As shown in FIG. 7, a brake case portion 75 is provided on the side portion of the transmission case 11, and the axle case 76 extends laterally outward from the brake case portion 75. A deceleration case portion 77 is provided at the base of the axle case 76.

A rear wheel differential mechanism 17 is provided inside the transmission case 11. The output shaft 17a of the rear wheel differential mechanism 17 extends from the side gear 79 to the inside of the reduction case portion 77. The rear wheel axle 80 is rotatably supported inside the axle case 76 in a state where the rear wheel axle 80 is located on the lateral outer side of the vehicle body of the rear wheel differential mechanism 29. The output shaft 17a and the rear wheel axle 80 are provided so as to be located on the same shaft core. A locking device 82 that enables differential locking of the rear wheel differential mechanism 17 is provided over the side gear 79 and the differential case 81.

Inside the deceleration case portion 77, a planetary deceleration mechanism 83 is provided over the output shaft 17a and the rear wheel axle 80. The planetary speed reduction mechanism 83 has a sun gear 83a driven by an output shaft 17a, an internal gear 83b supported by a speed reduction case portion 77, and a plurality of planetary gears 83c arranged in the circumferential direction of the sun gear 83a. .. The carrier 83d that supports the plurality of planetary gears 83c is connected to the rear wheel axle 80. A stopper 83e for preventing the carrier 83d from coming off the rear wheel axle 80 is attached to the rear wheel axle 80 by a bolt 84.

In the rear wheel differential mechanism 17, the power of the input shaft 17b is transmitted to the output shaft 17a via the differential case 81 and the side gear 79. The power of the output shaft 17a is decelerated by the planetary speed reduction mechanism 83 and transmitted to the rear wheel axle 80 to drive the rear wheel axle 80, and the rear wheel 2 is driven by the rear wheel axle 80.

A brake 85 is provided inside the brake case portion 75. The brake 85 is provided on a plurality of friction plates 86 and a brake case portion 75 locked in a portion of the output shaft 17a between the differential case 81 of the rear wheel differential mechanism 17 and the planetary reduction mechanism 83. It has a friction plate 88 locked to the support portion 87. A friction plate receiving portion 89 for receiving the friction plate 86 and the friction plate 88 is provided on the side where the planetary speed reduction mechanism 83 is located with respect to the friction plate 86 and the friction plate 88. The friction plate receiving portion 89 is fixed to the brake case portion 75. A hydraulic piston 90 is provided on the side opposite to the side where the friction plate receiving portion 89 is located with respect to the friction plate 86 and the friction plate 88.

As shown in FIG. 7, the output shaft 17a is configured to be supported by the support member 91 between the differential case 81 and the planetary speed reduction mechanism 83. The support member 91 is configured to engage with the output shaft 17a in a direction along the axis of the output shaft 17a so as to be relatively immovable.

Specifically, as shown in FIG. 7, the support member 91 is attached to a portion of the output shaft 17a between the friction plate 86 that engages with the output shaft 17a and the planetary deceleration mechanism 83. .. The support member 91 includes an inner ring 91a that is outerly fitted to the output shaft 17a, an outer ring 91b that is innerly fitted into an assembly hole formed in the friction plate receiving portion 89, and a rolling element 91c interposed between the inner ring 91a and the outer ring 91b. It is composed of bearings provided with. The support member 91 engages with the output shaft 17a in a relative immovable manner due to friction between the inner ring 91a and the output shaft 17a. The support member 91 is supported by the brake case portion 75 by being supported by the friction plate receiving portion 89.

In the brake 85, the operating hydraulic pressure is supplied to the hydraulic piston 90 to enter the on state, the brake is applied to the rear wheels 2, and the supply of the operating hydraulic pressure to the hydraulic piston 90 is released, so that the brake 85 is in the off state. Then, the brake on the rear wheel 2 is released.

That is, when the operating hydraulic pressure is supplied to the hydraulic piston 90, the hydraulic piston 90 is pressed toward the friction plate 86 by the operating hydraulic pressure, and the friction plate 86 and the friction plate 88 are along the axis of the output shaft 17a by the hydraulic piston 90. It is pressed in the direction and pressed against the friction plate receiving portion 89, and the friction braking force generated by the friction plate 86 and the friction plate 88 is applied to the rear wheel axle 80 via the output shaft 17a and the planetary deceleration mechanism 83.

When the supply of the operating hydraulic pressure to the hydraulic piston 90 is released, the pressure of the hydraulic piston 90 toward the friction plate 86 is released, and the pressure contact of the friction plate 86 and the friction plate 88 to the friction plate receiving portion 89 is released. The generation of friction braking force by the friction plate 86 and the friction plate 88 is released.

For example, when the brake 85 is operated in the engaged state, the support member 91 prevents the output shaft 17a from moving along with the friction plate 86, and after the brake 85 is returned to the disengaged state, the output shaft 17a It is possible to prevent the output shaft 78 from being subjected to rotational resistance while the friction plate 86 and the friction plate 88 of the support portion 87 remain in contact with each other.

[Another Embodiment]
(1) In the above-described embodiment, the example in which the rear wheel 2 is the drive target is shown, but the present invention is not limited to this, and the front wheel may be the drive target.

(2) In the above embodiment, an example in which the support member 91 is provided in the portion of the output shaft 17a between the brake 85 and the planetary deceleration mechanism 83 is shown, but the present invention is not limited to this, and the output shaft 17a The support member 91 may be provided at a portion between the rear wheel differential mechanism 29 (wheel differential mechanism) and the brake 85.

(3) In the above-described embodiment, an example in which the support member 91 is a bearing is shown, but the present invention is not limited to this. For example, bushes and impregnated metals can be used.

(4) In the above-described embodiment, the example in which the bearing is supported by the friction plate receiving portion 89 is shown, but the present invention is not limited to this, and a dedicated holder for supporting the bearing may be provided.

The present invention is provided over the wheel differential mechanism, the axle located on the lateral outer side of the vehicle body of the wheel differential mechanism, and the output shaft and the axle in the wheel differential mechanism, and reduces the power of the output shaft to reduce the axle. It has a planetary deceleration mechanism that transmits to, and a friction plate that is locked to the part of the output shaft between the differential case and the planetary deceleration mechanism in the wheel differential mechanism, and friction control is applied to the axle via the output shaft. Applicable to work vehicles equipped with powering brakes.

17 Wheel differential mechanism (rear wheel differential mechanism)
17a Output shaft 80 Axle (rear wheel axle)
81 Differential case 83 Planetary deceleration mechanism 85 Brake 86 Friction plate receiving part 91 Support member (bearing)

Claims (4)

Wheel differential mechanism and
Axles located on the lateral outer side of the vehicle body of the wheel differential mechanism and
A planetary deceleration mechanism provided over the output shaft and the axle of the wheel differential mechanism to reduce the power of the output shaft and transmit it to the axle.
Among the output shafts, a friction plate locked at a portion between the differential case of the wheel differential mechanism and the planetary deceleration mechanism is provided, and a friction braking force is applied to the axle via the output shaft. Brake and
A support member that supports the output shaft between the differential case and the planetary deceleration mechanism is provided.
The support member is a work vehicle configured to engage with the output shaft in a direction along the axis of the output shaft so as to be relatively immovable. The work vehicle according to claim 1, wherein the support member supports a portion of the output shaft between the friction plate and the planetary deceleration mechanism. The work vehicle according to claim 1 or 2, wherein the support member is a bearing that is externally fitted to the output shaft. The brake is configured to press the friction plate in a direction along the axis of the output shaft and press contact with the friction plate receiving portion.
The work vehicle according to claim 3, wherein the bearing is supported by the friction plate receiving portion.

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