JP2789147B2 - Power transmission device for transport vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a hydraulic transmission having a pair of hydraulic transmissions arranged adjacent to each other in the lateral direction of a vehicle body, and a transmission input shaft of each hydraulic transmission connected to a common drive source via a transmission means. The present invention relates to a power transmission device for a transport vehicle in which a transmission output shaft of a hydraulic transmission is connected to drive shafts of left and right drive wheels, respectively.

[0002]

2. Description of the Related Art Conventionally, as a power transmission device for such a vehicle, for example, US Pat. No. 4,809,796, US Pat. No. 4,819,508, or US Pat.
No. 76325 is known.

[0003]

By the way, a power transmission device using the above-mentioned hydraulic transmission is often provided in a work vehicle. However, such a work vehicle is required to efficiently work in a narrow place. It is desirable to make the body size as small as possible. However, what is described in the above-mentioned US Pat. No. 4,809,796 is to dispose the engine above the left and right hydraulic transmissions,
The engine and both hydraulic transmissions are connected by two endless belts wound around a pulley rotating around an axis extending in the vertical direction of the vehicle body, and the one described in the above-mentioned U.S. Pat. The engine disposed above and the two hydraulic transmissions are connected by two endless belts wound around pulleys rotating around an axis extending in the vehicle longitudinal direction. When these layouts are adopted, not only does the engine protrude upward to increase the vehicle height, but it is also difficult to reduce the overall width of the vehicle because the left and right hydraulic transmissions cannot be placed close enough. It is.

On the other hand, the engine disclosed in the above-mentioned US Pat. No. 3,776,325 has an engine disposed behind right and left hydraulic transmissions, and a bevel gear and a propeller shaft extending in the vehicle longitudinal direction from the engines and both hydraulic transmissions. Connected by The transmission output shafts of both hydraulic transmissions are connected to the left and right axles disposed at lower positions through a reduction mechanism. When this layout is employed, the engine does not protrude upward and the vehicle height can be reduced, but there is a problem that the vehicle height is increased by the amount that the axle is deviated below the transmission output shaft.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and has a vehicle body having a pair of hydraulic transmissions as small as possible in size and a lower center of gravity of the vehicle.
It is intended to achieve the above effectively .

[0006]

In order to achieve the above object, according to the Invention The present invention, in the carrier of the lower, connected to each other via the oil passage
A pair of hydraulic transmissions each having a hydraulic pump and a hydraulic motor are disposed adjacent to each other in the lateral direction of the vehicle body, and a transmission input shaft connected to the hydraulic pump of each hydraulic transmission is transmitted to a common drive source. And the hydraulic motor of each hydraulic transmission
Mission output shaft connected to a power transmission device of the transport vehicle and connected to a drive shaft of the left and right drive wheels, toward the transmission input shaft and a transmission output shaft to a vehicle body inside and outside each of the hydrostatic transmission and
Extend at approximately the same height, and at the outer end of each mission output shaft
The deceleration means and the drive shaft, which are arranged on the same axis with respect to the output shaft , are sequentially connected to the outside of the vehicle body.
The driving source is on the rear side of the loading platform and the driving wheels,
A first feature is that the lower end of the drive source is located lower than the drive shaft .

Further, the present invention provides, in addition to the first feature described above,
A second feature is that at least a part of the deceleration means is arranged in a movement locus of a crawler wound around the drive wheel.

[0008]

An embodiment of the present invention will be described below with reference to the drawings.

1 to 3 show an embodiment of the present invention. FIG. 1 is an overall side view of a carrier, FIG. 2 is a sectional view taken along line 2-2 of FIG. 1, and FIG. 3 is a right hydraulic transmission. It is an expanded sectional view of.

As shown in FIGS. 1 and 2, a walking-type transport vehicle V running by a pair of right and left crawlers 1 and 1
Two main frames 2, 2 extending in the vehicle longitudinal direction;
A cross member 3 for connecting the central portions of the main frames 2 and 2 in the left-right direction, a rear frame 4 made of a bent pipe material connected to the rear ends of the main frames 2 and 2, and the rear frame 4 And two cross members 5 and 6 connected in the left-right direction.

At the rear end of the rear frame 4, an engine E as a driving source for traveling is supported in a state where the engine E is deviated rightward from the vehicle center line, and a crankshaft 7 of the engine E is supported.
, Two drive pulleys 8, 8 are fixed. A pair of left and right hydraulic transmissions 10, 10 are supported adjacent to each other on a transmission support member 9 fixed to the front portion of the rear frame 4, and the transmission input shafts 11, 10 project from the hydraulic transmissions 10, 10 so as to face each other. 1
The driven pulleys 12 and 12 are fixed to the first and second pulleys 1, respectively. The pair of driving pulleys 8 and 8 and the pair of driven pulleys 1
Endless belt 1 as endless transmission member between 2 and 12
3 and 13 are wound. The endless belts 13, 13 are disposed so as to be distributed to the left and right of the vehicle body center line, and are disposed so as to rotate in a vertical plane extending in the vehicle longitudinal direction.

A pair of left and right driven wheels 15, 15 is attached to a driven shaft 14 disposed at the front end of the main frames 2, 2 in the left-right direction.
Are rotatably supported, and between the driven wheels 15, 15 and drive wheels 17, 17 fixed to drive shafts 16, 16 projecting outward from the respective hydraulic transmissions 10, 10.
The crawlers 1 and 1 are wound respectively. Also, the two front and rear playwheel shafts 18, 18; 19, 19 extending outward from the left and right main frames 2, 2 have crawlers 1, 1 respectively.
The free wheels 20, 20; 21, 21 abutting on the inner periphery of the lower part are rotatably supported.

A loading platform 24 is supported on the upper portions of the main frames 2 and 2 via front and rear brackets 22, 22; 23 and 23, and a handle pipe 25 extending rearward and upward from the loading platform 24 has a handle 26 at the rear end. , 26 are mounted.

As shown in FIG . 1 and FIG .
The gin E is located behind the drive wheel 17 and the loading platform 24.
Therefore, the lower end of the engine E is lower than the drive shaft 16.
In position.

As shown in FIG. 3, the hydraulic transmission 10 disposed on the right side of the vehicle body includes an inner casing 28 and an outer casing 29 which are connected with a partition plate 27 interposed therebetween. Ball bearing 3 provided on inner casing 28
0 and the partition plate 27, the mission input shaft 11 is rotatably supported, the driven pulley 12 is spline-coupled to the inner end of the mission input shaft 11, and a charge pump comprising a trochoid pump is provided at the outer end. 31
Is attached. Oil pressure mounted on transmission input shaft 11
An axial piston pump 32 as a pump includes a rotor 33 that rotates integrally with the transmission input shaft 11, a plurality of cylinders 34 formed in the outer periphery of the rotor 33 in the axial direction, and slidably fits in the cylinder 34. Pistons 36 urged in the projecting direction by springs 35
And a movable swash plate 37 for guiding the tip of the piston 36.

On the other hand, the transmission output shaft 3 is provided between the ball bearing 38 provided on the inner casing 28 and the partition plate 27.
9 is parallel to the transmission input shaft 11 and substantially at the same height
, And a brake 52 is mounted on the inner end of the transmission output shaft 39. Axial piston motor 40 as a hydraulic motor mounted on transmission output shaft 39
Is a rotor 4 that rotates integrally with the transmission output shaft 39.
1, a plurality of cylinders 42 formed in the outer periphery of the rotor 41 in the axial direction, a plurality of pistons 44 slidably fitted to the cylinders 42 and urged by a spring 43 in the protruding direction. And a fixed swash plate 45 for guiding the tip of the swash plate 44. The axial piston pump 32 and the axial piston motor 40 are connected to the partition plate 2.
7 are connected to each other via an oil passage (not shown) formed in the apparatus.

The outer casing 29 has a ball bearing 4
The drive shaft 16 is supported coaxially with the transmission output shaft 39, and the outer end of the transmission output shaft 39 is supported by the drive shaft 16 at the inner end via a needle bearing 47. Carrier 4 formed integrally with drive shaft 16
8, a planetary gear 49 is rotatably supported. The planetary gear 49 meshes with a ring gear 50 fixed to the inner surface of the outer casing 29 and a pinion 51 fixed to the transmission output shaft 39. The carrier 48, the planetary gear 49, the ring gear 50, and the pinion 51
Cooperate with each other and have the same shaft with respect to the transmission output shaft 39.
A speed reduction mechanism 53 is configured as speed reduction means arranged on a line .
As is clear from FIG. 2, the hydraulic transmission 1
The outer half portions of the crawlers 0 and 10, that is, the reduction mechanism 53 accommodated therein are disposed by utilizing the inner space of the trajectories of the crawlers 1 and 1, thereby reducing the overall width of the transport vehicle V. You.

The hydraulic transmission 10 disposed on the left side of the vehicle body has the same structure as the above-described hydraulic transmission 10 disposed on the right side of the vehicle body, which is plane-symmetrical.
The overlapping description is omitted.

Next, the operation of the embodiment of the present invention having the above configuration will be described.

The driving force of the engine E is determined by driving pulleys 8, 8 provided on the crankshaft 7, endless belts 13, 13,
And transmission input shafts 11, 11 of the left and right hydraulic transmissions 10, 10 via driven pulleys 12, 12.
Is transmitted to For example, when the transmission input shaft 11 of the right hydraulic transmission 10 rotates, an axial piston pump 32 provided on the transmission input shaft 11 is rotated.
Operates to discharge pressure oil. That is, when the rotor 33 of the axial piston pump 32 rotates together with the piston 36, the piston 36 whose distal end is guided by the movable swash plate 37.
Reciprocates in the cylinder 34 once per rotation of the transmission input shaft 11, and supplies pressure oil to the axial piston motor 40 via an oil passage (not shown) formed in the partition plate 27.

When pressure oil is supplied to the cylinder 42 of the axial piston motor 40, the piston 44 is fixed to the fixed swash plate 45.
, And its piston 44 is fixed to the fixed swash plate 45.
The rotor 41 rotates together with the transmission output shaft 39 due to the reaction force received from the rotor. At this time, by controlling the tilt angle of the movable swash plate 37 of the axial piston pump 32 to change the discharge oil amount and discharge direction, the rotation speed and rotation direction of the transmission output shaft 39 can be arbitrarily adjusted. it can. The rotation of the transmission output shaft 39 is a pinion 5
1, the transmission is transmitted to the drive shaft 16 via a speed reduction mechanism 53 composed of a planetary gear 49 and a ring gear 50, and drives the right crawler 1 via a drive wheel 17 fixed to the drive shaft 16.

On the other hand, the left crawler 1 can be driven in any direction at any speed by the hydraulic transmission 10 on the left by the same operation. Therefore, by independently controlling the driving of the left and right crawlers 1, 1, the transport vehicle V can travel straight and turn.

Now, a pair of endless belts 13, 13 for transmitting the driving force of the engine E to the left and right hydraulic transmissions 10, 10 are formed by the two hydraulic transmissions 10, 10.
Between the transmissions 10 and 10, the pair of driven pulleys 12 and 12 and the pair of endless belts 13 and 13 are arranged so that the transmissions 10 and 10 can rotate in a vertical plane extending in the vehicle longitudinal direction. It is possible to dispose them close to each other at a narrow interval as much as possible, and since the left and right reduction mechanisms 53, 53 are disposed using the inner space of the movement trajectory of the crawlers 1, 1, the transport vehicle The entire width of V can be reduced. Further, since the engine E is disposed behind the left and right hydraulic transmissions 10, 10 and the speed reduction mechanisms 53, 53 and the drive shafts 16, 16 are provided coaxially with the transmission output shafts 39, 39, the vehicle height is minimized. It is possible to keep it to a minimum. Further, the crankshaft 7 of the engine E, the hydraulic transmissions 10, 10
Mission input shafts 11, 11 and mission output shaft 3
9, 39, and drive shaft 1 of left and right drive wheels 17, 17
Since both of the power supply units 6 and 16 are arranged in parallel, the power transmission path can be simplified and the power loss can be reduced.

Although the embodiment of the present invention has been described in detail above, the present invention is not limited to the above-described embodiment, and various small design changes can be made.

For example, in the embodiment, the transport vehicle V having the crawlers 1 and 1 has been exemplified. However, the present invention is also applicable to a vehicle having no crawlers 1 and 1 and having driving wheels 17 and 17 as tires. Can be. Also, the left and right hydraulic transmissions 10, 10, instead of driving by the corresponding pairs of drive pulleys 8,8, the endless belt 13 and the driven pulley 12 and 12, the mission of the hydraulic transmission 10, 10 The input shafts 11 and 11 are integrally connected to form a common drive pulley 8 and an endless belt 1.
3, and driven by the driven pulley 12. Furthermore, it is also possible to use an endless chain or gear instead of the endless belts 13, or to drive with a drive shaft and a bevel gear.

[0026]

As described above, according to the first feature of the present invention, the transmission input shafts of the pair of left and right hydraulic transmissions are arranged toward the inside of the vehicle body so that they face each other. The structure of the transmission means for connecting the two transmission input shafts to the common drive source between the pair of hydraulic transmissions can be simplified to reduce the overall width of the vehicle .

Further deceleration means and the drive shaft are sequentially connected toward the outside of the vehicle body, especially on the outer end of each mission output shaft Mille
The output shaft, deceleration means and drive shaft are coaxially arranged.
Since the, and its mission output shaft and the mission input shaft
The height of the hydraulic transmission itself
Combined with the effect of lowering the
Transmission system from the transmission to each drive wheel via each reduction means
Height can be as low as possible.
It is located on the rear side of the table and drive wheels, and its lower end is the drive shaft.
Lower than the loading platform, hydraulic transmission
Of the drive source while avoiding interference with the
The installation height can be made as low as possible. As a result, the vehicle
The center of gravity of the vehicle can be effectively reduced.
Stability during running and loading is improved.

Further, avoid mutual interference between the drive source and the carrier.
In addition, the platform height can be set as low as possible and the platform effective surface
Loading can be secured as widely as possible, so loading and unloading of cargo on the loading platform
Eases work and improves loading capacity of the carrier
be able to.

According to the second feature of the present invention, at least a part of the speed reduction means is disposed by utilizing the inner space of the movement trajectory of the crawler wound around the driving wheels, so that the overall width of the vehicle is further reduced. Can be done.

[Brief description of the drawings]

FIG. 1 is an overall side view of a transport vehicle (a cross-sectional view taken along line 1-1 in FIG. 2).

FIG. 2 is a sectional view taken along line 2-2 of FIG.

FIG. 3 is an enlarged sectional view of the right hydraulic transmission.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Crawler 10 Hydraulic transmission 11 Transmission input shaft 13 Endless belt (transmission means) 16 Drive shaft 17 Drive wheel 24 Carrier 32 Axial piston port as hydraulic pump
Axial piston motor as a pump 39 transmission output shaft 40 hydraulic motor
Motor 53 Reduction mechanism E as reduction means Engine (drive source)

Claims (2)

(57) [Claims] 1. A phase shifter is provided below a carrier (24) through an oil passage.
The hydraulic pump (32) and the hydraulic motor (4
0) each having a pair of hydraulic transmissions (1
0) are disposed adjacent to each other in the lateral direction of the vehicle body, and the transmission input shaft (11) connected to the hydraulic pump (32) of each hydraulic transmission (10) is transmitted to a common drive source (E). The transmission output shaft (39) connected to the hydraulic motor (40) of each hydraulic transmission (10) and the driving output shaft (39) of the left and right driving wheels (17), while being connected via the (13). Transmission device for transport vehicles connected to each other
The transmission input shaft (11) and the transmission output shaft (39) of each of the hydraulic transmissions (10) extend toward the inside and outside of the vehicle body and at substantially the same height , respectively, so that each transmission output shaft ( 39) is provided at the outer end of the output shaft (3).
9), the deceleration means (5
3) and the drive shaft (16) are sequentially connected to the outside of the vehicle body , and the drive source (E) is connected to the carrier (24) and the drive
It is located on the rear side of the wheel (17), and its drive source (E)
A power transmission device for a transport vehicle, wherein a lower end is located lower than the drive shaft (16) . 2. The device according to claim 1, wherein at least a part of said speed reducing means is arranged in a movement locus of a crawler wound around said driving wheel.
Power transmission device for transport vehicles.