JPH05213077A - Hst integral type axle drive device - Google Patents

Abstract

PURPOSE:To divide an axle case into two upward and downward and support in fixation axles and a HST transmission at divided surfaces and constitute an HST integral type axle drive device of the axle case alone. CONSTITUTION:In an axle case, a hydraulic pump P, a hydraulic motor M, a set of gears connected to the output shaft of the hydraulic motor M and a differential gear mechanism drive by means of this set of gears, are housed. In addition, at an axle drive device that protrudes on both sides of the axle case a pair of axles 6L and 6R driven by means of the differential gear mechanism, a pair of oil passages are provided at a manifold 10 combining the valve sets of the hydraulic pump P and the hydraulic motor M, and connection is made respectively to the entrance port of the hydraulic pump P and the entrance port of the hydraulic motor M and a closing circuit is formed, and this manifold 10 is also housed and fixed at the inside of the axle case.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a traveling work vehicle,
The present invention relates to a configuration of a small-sized HST-integrated axle drive device used as a gear shift drive device for an axle.

[0002]

2. Description of the Related Art Conventionally, a technique in which an HST transmission is provided by being attached to a transmission drive case for axles has been publicly known. For example, it is as described in JP-A-61-263835 and US Pat. No. 4,513,834. However, in the technique described in JP-A-61-263835, since the mounting body of the hydraulic pump and the hydraulic motor is exposed to the outside of the mission case, the joint surface between the mission case and the mounting body is There was a problem that oil leakage occurred.

Further, in the technique described in US Pat. No. 4,513,834, the HST transmission device is attached to the outside of the mission case, and the entire HST-integrated axle drive device can be made compact and compact. There was a problem that it was not there.

[0004]

SUMMARY OF THE INVENTION According to the present invention, an HST transmission device, a gear reduction device and a differential gear device are installed in an axle case that supports an axle, and the left and right axles, a hydraulic pump shaft and a swash plate are provided from the axle case. The HST-integrated axle drive device is constructed only by the axle case with the rotation shaft protruding. For this purpose, the axle case is vertically divided into two parts by a horizontal line passing near the axis of the axle, and the axle and the HST
The transmission is supported and fixed.

[0005]

The object of the present invention is as described above. Next, the structure for achieving the object will be described.
The hydraulic pump P and the hydraulic pump P are provided in the axle case 11.
The hydraulic motor M driven by the pressure oil from, the gear train connected to the output shaft of the hydraulic motor M, and the differential gear mechanism driven by this gear train are housed,
In the axle drive device in which the pair of axles 6L and 6R driven by the differential gear mechanism are projected to both sides of the axle case 11, a pair of oil passages are provided in the manifold 10 that also serves as the valve seats of the hydraulic pump P and the hydraulic motor M. A closed circuit is formed by connecting the pair of oil passages to the inlet / outlet port of the hydraulic pump P and the inlet / outlet port of the hydraulic motor M, and the manifold 10 is also housed and fixed in the axle case 11. is there.

[0006]

[Operation] Next, the operation will be described. Since the oil passage connecting the hydraulic pump P and the hydraulic motor M is bored inside the manifold 10 and the manifold 10 itself is housed inside the axle case 11, the oil connecting the hydraulic pump P and the hydraulic motor M is arranged. Even if there is oil leakage from the road, the axle case 11
No longer leaked to the outside of. Further, since the hydraulic pump P and the hydraulic motor M are housed and arranged in the axle case 11 that supports the axles 6L and 6R, and shifts / drives, the axle drive device can be made compact. It has become.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The object and structure of the present invention are as described above. Next, the structure of the embodiment shown in the accompanying drawings will be described. 1 is an overall side view of a tractor equipped with an HST-integrated axle drive device of the present invention, FIG. 2 is an overall perspective view of an HST-integrated axle drive device, FIG. 3 is a side sectional view of the same, and FIG. 5 is a plan view of a portion of the lower axle case 11b in this state, FIG. 5 is a side sectional view of the same, FIG. 6 is an exploded view of a portion of the swash plate rotating shaft 8, and FIG. 7 is a sectional view of the hydraulic pump P.

The overall structure of the tractor equipped with the mower device R will be described with reference to FIG. Front wheel 1 that is the driving wheel
An engine E having a vertical crankshaft projecting thereon is mounted between the rear wheels 2 which are steering wheels. An output pulley 3 is fixed to the vertical crankshaft of the engine E. Power is transmitted from the output pulley 3 to the input pulley 4 of the HST-integrated axle driving device via a V belt 5 stretched horizontally. The input pulley 4 is fixed to the pump shaft 9 of the hydraulic pump P of the HST-integrated axle drive device.

The axles 6L and 6R of the tractor are projected horizontally to the left and right, whereas the pump shaft 9 of the hydraulic pump P is arranged vertically in parallel with the vertical crankshaft. As shown in FIG. 1, the mower device R can be used as the front mower device R, or can be attached to the abdomen of the tractor as the mid mower device R ′.

2 to 6, the specific structure of the HST-integrated axle drive device will be described. In the present invention, the axle case 11 that supports the axles 6L and 6R and drives the engine E while changing the power of the engine E is configured to be flat in a side view as shown in FIG. 1, and is arranged horizontally. .. Then, replace the axle case 11 with the axle 6L.
The upper axle case 11a and the lower axle case 11b are divided into two parts in the vicinity of the axis line of 6R or just above and below the axis line. Then, on the upper and lower parting lines, the axle 6L
・ 6R, reduction shaft 18, and manifold 10 that doubles as a valve seat
It is sandwiched and supported.

As is well known in the construction of HST transmissions, the manifold 10 has an oil passage bored therein,
The hydraulic pump P and the hydraulic motor M are connected to form a closed circuit. The oil passage also serves as a valve and a valve seat for guiding the high pressure oil of the hydraulic pump P and the hydraulic motor M, and the low pressure oil to the respective closed circuits. That is, the bearings of the axles 6L and 6R and the reduction shaft 18 are the same as the lower axle case 1
Half bearing surface provided on the upper surface of 1b and upper axle case 11
By joining the half bearing surface provided on the lower surface of a,
It is configured with one bearing hole.

For the hydraulic pump P and the hydraulic motor M, the hydraulic motor M is set downward and the hydraulic pump P is set upward.
The manifold 10 also serving as a valve seat is interposed between them to be fixed from above and below to form an HST set. The HST
A suction oil passage is provided on the side of the set for charging hydraulic oil,
The oil passages between the upper and lower hydraulic pumps P and the hydraulic motor M are communicated with each other via the manifold 10 which also serves as a valve seat. The manifold 10 is formed into a square plate in a plan view, and the manifold 10 is supported and fixed by being sandwiched between the upper axle case 11a and the lower axle case 11b.

That is, as shown in FIGS. 4 and 5, the holding and fixing seat 1 of the manifold 10 is provided on the lower surface of the upper axle case 11a.
1c is provided, a placement fixing seat 11d is provided on the upper surface of the lower axle case 11b, and the holding fixing seat 11c is also provided on the placement fixing seat 11d.
Is also a square seat, and the portion of the manifold 10 of the HST set is arranged in this portion to make the upper axle case 11
By joining a and the lower axle case 11b, they can be fixed similarly to the axles 6L and 6R and the reduction shaft 18.

Above the hydraulic pump P is the upper axle case 11
An opening is provided in a, and this portion is closed by a seal lid 12 provided with an oil seal. Further, it is necessary to operate the rotary swash plate 25 of the hydraulic pump P to change the discharge direction and discharge amount of the pressure oil, and the swash plate rotary shaft 8a for operating the rotary swash plate 25 is engaged with the engaging groove portion. It discharges as a certain axis. The upper axle case 11 in the portion where the swash plate rotation shaft 8a is arranged
An opening is provided in a, and as shown in FIG. 6, the operation lever shaft 8b fitted in the engaging groove portion is integrally formed with the seal lid so that it can be attached from the outside.

Further, the hydraulic motor M is fixedly installed on the lower surface of the manifold 10 which also serves as a valve seat, inside which a fixed swash plate 16, a rotor 22 and a piston 23 are provided. The pressure oil is the rotor 22
The piston 23 is pushed out by flowing into the cylinder hole bored in, and the rotational force of the rotor 22 is generated by being pushed by the fixed swash plate 16. The rotational force of the rotor 22 is transmitted to the motor shaft 24 to rotate the output gear 13. By inserting the HST set from above, the output gear 13 is configured to mesh with the large diameter gear 14.

A gear speed reducer is provided between the output gear 13 and the differential gear device. Hydraulic pump P
Is constructed as shown in FIG. A swash plate rotating shaft 8a that can be operated by an operating lever shaft 8b is provided from the outside of the upper axle case 11a, and the hydraulic pump P is driven by the swash plate rotating shaft 8a.
The swash plate 25 inside is rotated. The piston 26 of the rotor 27 fixed to the hydraulic pump shaft 9 discharges pressure oil by rotating the rotation swash plate 25 in a pressed state, and discharges the pressure oil by rotation of the rotation swash plate 25. The direction and the discharge amount are changed.

By changing the discharge direction and the discharge amount of the pressure oil of the hydraulic pump P, the hydraulic motor M can be continuously stepped forward, neutral and reverse. The pressure oil discharged from the hydraulic pump P is guided through the manifold 10 into the cylinder formed in the rotor 22 of the hydraulic motor M.

Next, the structure of the gear reduction device will be described. From the small diameter gear 13 fixedly mounted on the motor shaft 24, it is transmitted to the large diameter gear 14 on the reduction shaft 18. The reduction shaft 18
Another small-diameter gear 15 is engaged with the ring gear 7 of the differential gear device. The diff gear device does not have a gear case, and the hole of the inner diameter of the ring gear 7 also serves as the gear case. The pinion shaft 1 is attached to the inner diameter of the ring gear 7.
7 is fixed, and the left and right axles 6 are attached to the center of the pinion shaft 17.
It constitutes an opposing pivot hole at the inner end of L · 6R.

The pinions 19 and 20 loosely fitted to the pinion shaft 17 mesh with the differential side gears 21L and 21R,
Splines at the inner ends of the axles 6L and 6R are fitted and fitted into the differential side gears 21L and 21R.

FIG. 8 shows the case of the hydraulic pump P and the case of the hydraulic motor M as an upper axle case 11a and a lower axle case 11.
9 is a side sectional view of the same, and FIG. 10 is a rear sectional view of the same. Above are the hydraulic pump P and hydraulic motor M in each case, the upper part.
The interior of the lower axle case 11a, 11b,
As shown in FIGS. 8 to 10, each case of the hydraulic pump P and the hydraulic motor M may be used as the upper axle case 11a and the lower axle case 11b.

The manifold 10, which also serves as a valve seat, is fitted and fixed to a mounting fixing seat 11d formed only on the lower axle case 11b side, and a hydraulic pump P is installed on the upper surface of the manifold 10 to place a space between the hydraulic motor side and the hydraulic pump P. The oil passage is connected to form an open circuit. The fixed swash plate 16 is the lower axle case 11
It is fixed to the bottom of b.

[0022]

Since the present invention is configured as described above, it has the following effects. First, the hydraulic pump P
An oil passage connecting the hydraulic motor M with the manifold 10
Since the manifold 10 itself is housed and arranged inside the axle case 11, even if there is an oil leak from an oil passage connecting the hydraulic pump P and the hydraulic motor M, the manifold 10 itself is placed outside the axle case 11. It no longer leaks.

Secondly, by supporting the axles 6L and 6R, gear shifting and
Since the hydraulic pump P and the hydraulic motor M are housed and arranged in the driven axle case 11, the axle drive device can be made compact.

[Brief description of drawings]

FIG. 1 is an overall side view of a tractor equipped with an HST-integrated axle drive device of the present invention.

FIG. 2 is an overall perspective view of an HST-integrated axle drive device.

FIG. 3 is a side sectional view of the same.

FIG. 4 is a lower axle case 1 with the HST set removed.
The top view of the part of 1b.

FIG. 5 is a side sectional view of the same.

FIG. 6 is an exploded view of a portion of a swash plate rotating shaft 8.

FIG. 7 is a sectional view of a hydraulic pump P.

FIG. 8 shows each case of the hydraulic pump P and the hydraulic motor M,
FIG. 4 is an exploded plan view of an embodiment in which the upper axle case 11a and the lower axle case 11b are combined.

FIG. 9 is a side sectional view of the same.

FIG. 10 is a rear sectional view of the same.

[Explanation of symbols]

 P hydraulic pump M hydraulic motor E vertical crankshaft type engine 8 swash plate rotating shaft 9 pump shaft 10 manifold that also serves as valve seat 11 axle case 11a upper axle case 11b lower axle case

Claims (1)

[Claims] 1. A hydraulic pump P in an axle case 11,
Hydraulic motor M driven by pressure oil from the hydraulic pump P
And a gear train connected to the output shaft of the hydraulic motor M and a differential gear mechanism driven by the gear train, and the pair of axles 6L and 6R driven by the differential gear mechanism are connected to the axle case 11 In the axle drive device projecting on both sides of the hydraulic pump P and the hydraulic motor M, a pair of oil passages are provided in the manifold 10 which also serves as valve seats of the hydraulic pump P and the hydraulic motor P. An HST-integrated axle drive device, characterized in that a closed circuit is formed by connecting to each of the inlet and outlet ports of the HST, and the manifold 10 is also housed and fixed inside the axle case 11.