JP2944556B2 - Axle drive - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an HST type axle drive device used as a tractor propulsion device.

[0002]

2. Description of the Related Art Conventionally, there has been known an axle drive device in which a case of an axle drive device is divided into upper and lower parts, the axle is supported by bearings on the divided surface, and the axle is driven by an HST type transmission attached to the case. It is being done. For example, Japanese Utility Model Publication No. Sho 62-44198 filed by the same applicant.

[0003]

However, in the prior art, the HST prepared completely separately from the axle driving device is used.
Since the variable speed transmission is exposed and supported outside the case of the axle drive unit, the overall size is large and the total weight is large, and the horizontally arranged axle is driven from the motor shaft of the hydraulic motor vertically arranged outside. Therefore, it was necessary to interpose a bevel gear device in both drive systems. Further, a spare tank for replenishing the reduction of the hydraulic oil in the HST type transmission is required, and in order to use the lubricating oil in the drive case as the hydraulic oil, the drive case and the HST type transmission are required. There was a problem that it was necessary to specially configure the pipes and oil passages that connect the two. In the present invention, in order to solve the above-mentioned conventional problems, HS
Both the hydraulic motor M and the hydraulic pump P of the T-type transmission,
Hydraulic motor M placed inside the axle drive case
The oil passage plate 3 connecting the oil pump P and the hydraulic pump P is also disposed inside. The oil passage plate 3 is formed of an L-shaped member and includes first and second legs extending in a direction perpendicular to each other. Further, in the oil passage plate 3, the oil passage from the hydraulic pump P to the hydraulic motor M is bent in the orthogonal direction so that the motor shaft is the same as the axle direction, and the rotation direction is conventionally changed by a bevel gear. The transmission direction is changed by the oil passage in the oil passage plate.

[0004]

The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described. The axle drive device according to claim 1,
Attached separately inside the mission case that constitutes
Oil passage plate, and the oil passage plate is formed by a substantially L-shaped member.
And disposed on the substantially L-shaped member at right angles to each other.
Equipped with mounting surfaces for hydraulic pump P and hydraulic motor M
On the mounting surface of the hydraulic pump P and the hydraulic motor M described above,
Are provided with a pair of fluid ports, and
Each of the fluid ports to the other of the mounting surfaces.
Internal oil passages that connect to each of the fluid ports
The substantially L-shaped member comprises a first and a second extending at right angles to each other.
The first leg extends horizontally, and
Wherein the second leg extends vertically and the first leg
Has an upper surface and a lower surface, and the pump mounting surface is placed on the upper surface.
And the second leg is provided on the upper surface of the first leg.
A first surface extending upward from a surface on which the second leg is located;
A second side opposite and parallel to the first side of the section.
The motor mounting surface is on a second surface of the second leg.
It is arranged in .

According to claim 2, the mission case is
Consists of at least two separable elements,
The two elements can be split on a horizontal split surface, and
HST type transmission and differential gear device inside the
D, and the HST-type transmissions
For hydraulic pump P and hydraulic motor M
Under block and oil separate from the mission case
The hydraulic pump P and the hydraulic motor
Oil passage connecting each cylinder block for M
This is provided on the oil passage plate .

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The objects and constitutions of the present invention are as described above, and the embodiments of the present invention shown in the attached drawings will be described below. FIG. 1 is a side view of a small tractor provided with an axle drive device of the present invention, FIG. 2 is a front sectional view of the axle drive device of the present invention, and FIG. 3 is a view of FIG. 4 is a sectional view taken along the line II-II in FIG. 2, and FIGS. 5 and 6 are perspective views showing another configuration of the oil passage plate 3.

FIG. 1 shows a small tractor on which an engine E having a vertical crankshaft is mounted.
A pulley is fixed to the vertical crankshaft of the engine E, and power is transmitted by a belt to the pulley fixed to the pump shaft 4 of the hydraulic pump P projecting upward from the axle driving device of the present invention. The tractor is provided with a rotary mower RR at the front or abdomen to perform lawn mowing or the like. The invention relates to the tractor axle 13
For driving an axle.

Referring to FIGS. 2, 3 and 4, the structure of the axle drive will be described in detail. The case of the axle drive device is constituted by upper and lower half cases 1 and 2, and the two cases are joined to constitute one closed transmission case. The bearings of the axles 13 and the motor shaft 5 are sandwiched between the joint surfaces of the upper half case 1 and the lower half case 2. Also, a mounting surface is formed on the lower surface of the half upper case 1, and the hydraulic passage plate 3 in a state where the hydraulic pump P and the hydraulic motor M are fixedly supported is mounted on the mounting surface with bolts 39 from below. It is. The oil passage plate 3 with the hydraulic motor M and the hydraulic pump P fixed thereto is attached to the lower surface of the half upper case 1 and joined to cover the lower half case 2 from below to cover the upper half case. 1 and the lower half case 2 are fastened with bolts. Since both the upper half case 1 and the lower half case 2 are made of aluminum die-cast, the number of machined parts is reduced and the cost is reduced.

The HST type transmission device housed and disposed inside the axle drive device of the present invention comprises a hydraulic pump P, an oil passage plate 3 and a hydraulic motor M, and the oil passage plate 3 is formed by an L-shaped member. A first extending perpendicular to each other
And a second leg. The oil passage plate 3 has a pump mounting surface 3d and a motor mounting surface 3e with the first leg portion and the second reverse portion orthogonal to each other as planes. A pair of half-moon oil passages are formed in the mounting surfaces of the pump mounting surface 3d and the motor mounting surface 3e, and the oil passages 3a and 3b are formed directly in the pair of half-moon oil passages of the motor mounting surface 3e. Oil passages 3a 'and 3b' are bored downward from the pair of half-moon oil passages on the mounting surface 3d, and are connected to the oil passages 3a and 3b. A cylinder block 10 of the hydraulic pump P is rotatably mounted on the pump mounting surface 3d, and a piston 12 is fitted inside the plurality of piston holes of the cylinder block 10 so as to be slidable up and down.

The bearing of the half upper case 1 and the pump mounting surface 3
When the pump shaft 4 supported by the spherical bush d is rotated, the cylinder block 10 and the piston 12 rotate,
By changing the angle of the thrust bearing 15 in contact with the upper end of the piston 12 with the swash plate 9, the discharge amount and discharge direction of the hydraulic pump P are changed, and the discharge pressure oil is supplied to the oil passage of the oil passage plate 3. The oil is sent to the hydraulic motor M from the oil passages 3a 'and 3b' via the oil passages 3a and 3b. The angle of the swash plate 9 can be changed in conjunction with the rotation of the shift lever shaft 6,
In the neutral position of the shift lever shaft 6, the detent device 2
0 is configured.

As shown in FIGS. 2 and 3,
A short-circuit valve 25 for short-circuiting between the two oil passages 3a and 3b on the discharge side and the return side is arranged. When the tractor is towed, the hydraulic motor M is driven,
The configuration is such that it is possible to avoid a situation in which pressure oil is supplied to the hydraulic pump P side. 7 is a short-circuit valve 25
Is an operation unit for operating. The short-circuit valve 25 and the operation unit 7 are of a push operation type in which the engagement state is eliminated so that the operation can be performed in the contact state. With this configuration, assembly becomes possible. A check valve 26/27 is interposed between the oil passages 3a and 3b of the oil passage plate 3 to form a replenishing oil passage 30, and a hydraulic oil suction hole 3c extending downward between the check valves 26/27. Is drilled.

Then, a sponge-shaped oil filter 8 is fitted to the lower end of the hydraulic oil suction port 3c, and the lower part of the oil filter 8 is prevented from coming off by abutting the lower half case 2. It is. Since the oil filter 8, the hydraulic oil suction hole 3 c and the check valves 26 and 27 are provided as the configuration and communicate with the oil passages 3 a and 3 b via the check valves 26 and 27, the operation of the hydraulic motor M and the hydraulic pump P is performed. When the operating oil decreases inside, the oil passages 3a and 3
A negative pressure is generated in b, and the lubricating oil in the case is sucked as hydraulic oil. O indicates the oil level of the lubricating oil filled in the transmission case.

The pump mounting surface 3d of the oil passage plate 3 is a surface on which the hydraulic pump P is mounted, and the same plane is formed slightly wider. It is configured on the surface to be attached. Oilway board 3
Cylinder block 1 on the motor mounting surface 3e
1 is rotatably mounted, presses the piston 14 with pressure oil from the oil passages 3a and 3b, and the piston 14 comes into contact with the thrust bearing 16, so that the cylinder block 11 and the motor shaft 5 rotate. Things. A spherical bush is used for a shaft support of the motor shaft 5 on the oil passage plate 3 side,
A spherical bush is also used on the other end side, and is held between upper and lower half cases 1 and 2. A gear 17 is engraved on the motor shaft 5, and the gear 17 is
It is in mesh with the upper gear 21.

The small-diameter gear 22 on the counter shaft 24 meshes with the ring gear 23 of the differential gear device D, and the differential gear device D gives differential rotation to the axles 13.
Is to be driven. A brake drum 18 is fixed to the tip of the motor shaft 5, and the brake shoe is opened and expanded by the brake lever 19 to contact the brake drum 18 to perform braking. FIG. 4 shows a portion of the motor mounting surface 3e with which the cylinder block 11 of the hydraulic motor M contacts.

FIGS. 5 and 6 show another configuration of the oil passage plate 3. In the case of the oil passage plate 3 ', a pump mounting surface 3'd and a motor mounting surface 3'e are configured to be parallel to the left and right, and the pump shaft 4 projects in a direction parallel to the axles 13. It is used in the case. In the case of the oil passage plate 3 ", the pump mounting surface 3" d is projected in the front-rear direction, and the motor mounting surface 3 "e is projected in parallel with the axles 13. In the case where the engine of the horizontal crankshaft is arranged above the axles 13, the belt drive becomes easy.By changing the configuration of the oil passage plate 3 as described above, the pump shaft 4 can change the projecting direction.

FIG. 7 is a rear sectional view of another embodiment in which the arrangement of the check valves 26 and 27 is changed, FIG. 8 is a plan view of the same, and FIG. 9 is a sectional view of the oil passage plate 3 in FIG. 10 is a sectional view taken along the line IV-IV in FIG. In the embodiment shown in FIGS. 2 and 3, the oil passages 3a and 3b and the supply oil passage 30 are arranged in the same plane position. When the road is juxtaposed, the pump mounting surface 3
Since the motor mounting surface 3e had to be separated from d, the oil passage plate 3 could not be made compact and the case became large with it. Therefore, in the embodiments of FIGS. The supply oil passage 30 is disposed within the thickness of the oil passage plate 3 below the oil passages 3a and 3b so as to overlap the oil passages 3a and 3b.

The replenishing oil passage 30 has an upper half portion connected to the oil passage 3a.
-It is drilled so as to overlap and communicate with the lower half of 3b. Thereby, an oil passage for connecting the two is unnecessary, and the thickness of the oil passage plate 3 can be reduced as much as possible. The lower oil filter 8 is located at the center of the supply oil passage 30.
The hydraulic oil suction hole 3c is opened toward the
Check valves 26 and 27 are provided on both sides of the supply oil passage 30 with the check valves 26 and 27 opened and closed to communicate with the oil passages 3a and 3b. Then, the replenishing oil from the hydraulic oil suction hole 3c flows to the oil passages 3a and 3b in the replenishing oil passage 30 at the position where the replenishing oil has passed the check valves 26 and 27. By arranging the oil passages 3a and 3b, the supply oil passage 30 and the oil filter 8 in the oil passage plate 3 in this manner, the motor mounting surface 3e can be formed closer to the pump mounting surface 3d. The road board 3 can be made compact. The rest of the configuration is the same as the configuration of the embodiment of FIGS.

[0018]

As described above, the present invention has the following advantages. Axle as claimed in claim 1
Installed separately inside the transmission case that constitutes the drive unit
An oil passage plate for attachment, the oil passage plate having a substantially L-shaped portion.
Material, on the substantially L-shaped member, at right angles to each other
The mounting surface for the hydraulic pump P and hydraulic motor M
Mounting surface of the hydraulic pump P and hydraulic motor M
Each provided with a pair of fluid ports,
Each of the fluid ports on one side is connected to the mounting surface
In connection with each of the fluid ports on the other side of
And a substantially L-shaped member extending at right angles to each other.
Consisting of a first and a second leg, the first leg being horizontal
And the second leg extends vertically, and
The first leg has an upper surface and a lower surface, and the pump mounting surface is
Resting on the upper surface, the second leg in front of the first leg
A first surface extending upward from a surface located on the upper surface,
A second leg opposite the first face of the second leg and parallel to the first face;
Surface, and the motor mounting surface is the first leg of the second leg.
2, the hydraulic pump P and the hydraulic motor M connected by the oil passage plate 3 arranged inside the transmission case are housed in the case of the axle drive unit. The axle drive device can be mounted even when the space for mounting on the axle is narrow. In addition, since the mounting surface of the hydraulic motor and the hydraulic pump is formed orthogonal to the oil passage plate 3 disposed inside the transmission case, in the case of a small tractor on which the engine E having a vertical crankshaft is mounted, the Power can be easily transmitted to the belt.

According to a second aspect, the number of transmission cases is small.
Consists of at least two separable elements,
The two elements can be freely divided by the horizontal dividing plane,
HST type transmission and differential gear D
And the HST type transmission is arranged so that the rotation axes are
Cylinders for hydraulic pump P and hydraulic motor M that are approximately right angle
Block and an oil passage plate separate from the transmission case
For the hydraulic pump P and the hydraulic motor M
Oil passage connecting each of the cylinder blocks
Since it is provided on the plate, the power transmission structure from the motor shaft 5 to the axle can be easily configured with gears, chains, and the like, and it is not necessary to change the direction of power transmission using a bevel gear device as in the related art. .

[Brief description of the drawings]

FIG. 1 is a side view of a small tractor provided with an axle drive device of the present invention.

FIG. 2 is a front sectional view of the axle drive device of the present invention.

FIG. 3 is a sectional view taken along the line II of FIG. 2 with the half upper case 1 removed.

FIG. 4 is a view taken in the direction of arrows II-II in FIG. 2;

FIG. 5 is a perspective view showing another configuration of the oil passage plate 3;

FIG. 6 is a perspective view showing another configuration of the oil passage plate 3;

FIG. 7 is a rear sectional view of another embodiment in which the arrangement of check valves 26 and 27 is changed.

FIG. 8 is a plan view of the same.

9 is a sectional view of the oil passage plate 3 in FIG.

FIG. 10 is a sectional view taken along the line IV-IV in FIG. 7;

[Explanation of symbols]

 1 Half upper case 2 Half lower case 3 Oil passage plate 3a / 3b Oil passage 3c Hydraulic oil suction hole 3d Pump mounting surface 3e Motor mounting surface 4 Pump shaft 5 Motor shaft 24 Counter shaft P Hydraulic pump M Hydraulic motor

Claims (2)

(57) [Claims] An axle drive unit includes a mission case.
Oil plate for separately mounting inside the
The oil passage plate is constituted by a substantially L-shaped member, and the substantially L-shaped member
Above, a hydraulic pump P and a hydraulic motor
The hydraulic pump P and the hydraulic motor
A pair of fluid ports on the mounting surface of
Each of the fluid ports on one of the mounting surfaces
That of the fluid port at the other of the mounting surfaces.
An internal oil passage is provided to connect with each other, and the substantially L-shaped members are mutually connected.
The first and second legs extend at right angles to each other,
Leg extends horizontally and said second leg is vertical
The first leg has an upper surface and a lower surface,
The pump mounting surface is placed on the top surface, and the second leg is
Extending upwardly from a surface of the first leg located on the upper surface.
On a first side opposite to the first side of the second leg,
And a second parallel surface, wherein the motor mounting surface is
An axle drive device, wherein the axle drive device is disposed on a second surface of the second leg . 2. The system according to claim 2, wherein the transmission case has at least two
It consists of detachable elements, the two elements being water
It can be divided on a flat dividing surface,
A HST type transmission and a differential gear D are arranged in the
The ST-type transmission is a hydraulic pump whose rotation axes are substantially perpendicular to each other.
Cylinder blocks for pump P and hydraulic motor M, and
And a separate oil passage plate from the transmission case
And a cylinder for the hydraulic pump P and the hydraulic motor M
An axle drive device characterized in that an oil passage connecting each of the blocks is provided on an oil passage plate .