JPH1178589A - Hydraulic pump driving device for tractor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To drive hydraulic pumps for hydraulic lifting device, power steering as well as hydraulic clutch system pressure with one driving gear by associating the driving gear of the hydraulic pumps with the input shaft of an independent PTO clutch in a PTO transmission. SOLUTION: A hydraulic pumps 80 is provided in the upper surface of a tractor car body 8 to be located slightly before a hydraulic lifting device 10, and it is a serial 3-continuous pump system composed of a pump 801 for system pressure, a pump 802 for the hydraulic lifting device 10 and a pump 803 for power steering. A pump driving gear 82 is connected to a gear 81 on the input shaft of the independent PTO clutch via a relay gear 83 so as to be associative. The pumps 801 to 803 are all gear pumps and formed in a unit including the driving gear 82 and the relay gear 83, and this unit is installed in the upper surface of the tractor car body 8 by providing the boss part 84A of a pump case 84 in the boss part 8A of the tractor car body 8 to be freely detached.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tractor hydraulic pump driving device.

[0002]

2. Description of the Related Art A tractor is a motive power vehicle, and is provided with a hydraulic lifting device having a lift arm on a rear upper surface of a tractor vehicle body so as to control lifting and lowering of various working machines. Conventionally, a gear pump is mainly used as a hydraulic pump as a hydraulic source of the hydraulic elevating device, and the hydraulic pump is configured to be directly mounted on a side of a mounted engine and driven by the engine.

When the hydraulic pump is directly mounted on the side of the engine, the tractor body (transmission case) is also used as a tank in the tractor, so the inlet piping member connecting the hydraulic pump and the tank becomes long. There was a first problem. Further, when the hydraulic pump is mounted directly on the side of the engine, the second problem is that the hydraulic pump protrudes outward from the side of the engine, so that the front wheel cut angle becomes smaller due to the protrusion of the hydraulic pump.

Japanese Unexamined Patent Publication No. Sho 63-304905 does not recognize (unintended) the first and second problems described above, but does not disclose the tractor body (located above the main case and in front of the intermediate case. ) Discloses a technology provided with a hydraulic pump at the top.

[0005]

According to the technique disclosed in the above publication, a propeller shaft, an input shaft interlocked with the propeller shaft, and an input shaft interlocked with the input shaft via a gear to drive the hydraulic pump by the engine. So many parts,
There is a third problem that members are required, cost is high, and maintenance of each part is difficult.

The present invention solves the above-described first to third problems and, in addition to the hydraulic pump for the hydraulic lifting device, uses a hydraulic pump for power steering and a system pressure for a hydraulic clutch (PTO system, traveling system). It is an object of the present invention to provide a tractor hydraulic pump drive device that can also drive the hydraulic pump with one drive gear.

[0007]

SUMMARY OF THE INVENTION The present invention relates to a tractor hydraulic pump driving apparatus having a hydraulic pump driven by an engine on an upper surface (upper part) of a tractor body. The following technical measures have been taken. That is, the hydraulic pump drive device for a tractor according to the present invention is characterized in that a drive gear of the hydraulic pump is interlocked with an input shaft of an independent PTO clutch in a PTO transmission (claim 1). .

By adopting such a configuration, the hydraulic pump can approach the tank without increasing the length of the piping member, and there is no restriction on the front wheel cutting angle. Not only can be solved, but also the input shaft of the independent PTO clutch can be used for driving the pump, thereby solving the third problem described above.

Further, in the tractor hydraulic pump driving apparatus according to the present invention, in addition to the structure of claim 1, a relief valve is provided on the discharge side of the hydraulic pump, and the oil discharged from the relief valve is used as an oil lubrication for the pump driving gear. (Claim 2). By adopting such a configuration,
The durability of the drive gear of the hydraulic pump was greatly improved, and the bite of the drive gear became smooth.

Further, in the tractor hydraulic pump driving apparatus according to the present invention, in addition to the constitutions of claims 1 and 2, the relief valve is used for a system circuit of an independent PTO clutch and a front wheel driving hydraulic clutch. (Claim 3). By adopting such a configuration,
The above-mentioned conventional patent (JP-A-63-304905)
The need for a lubrication pump was eliminated.

The tractor hydraulic pump driving device according to the present invention is characterized in that, in addition to the configuration of claim 1, the hydraulic pump is
It is characterized by comprising at least two units for the hydraulic lifting device and the power steering (claim 4). By adopting such a configuration,
A plurality of hydraulic pumps can be driven by one drive gear, and an expensive flow dividing valve (flow priority valve) is not required.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a pump driving apparatus according to the present invention will be described with reference to the drawings. The overall configuration of the transmission to which the present invention is applied (traveling transmission and PTO transmission)
Will be described with reference to FIG. 2 and the PTO transmission will be described with reference to FIGS. 3 and 4. Then, details of the hydraulic pump driving device according to the present invention will be described with reference to FIGS. Will be described.

In FIG. 1, a tractor 1 includes left and right front wheels 2.
And a two-axle four-wheel type having left and right rear wheels 3, and a cabin 6 is mounted so as to surround a steering handle 4 and a driver's seat 5. Of course, a tractor without the cabin 6 may be used. A tractor body 8 is formed by connecting a transmission case to a rear surface of the tractor engine 7 via a clutch housing.
A transmission including a traveling transmission and a PTO transmission shown in FIG. 2 is built therein.

A hydraulic elevating device 10 having left and right lift arms 9 is provided on the rear upper surface of the tractor body 8 and a work implement 12 shown as a rotary tiller in this example by a link mounting body 11 shown by a three-point link. The work machine 12 is drivable via a PTO shaft 13. In FIG. 2, an engine crankshaft (output shaft) 14
To the traveling system propulsion shaft 16 via the traveling system main clutch 15.
And a transmission shaft 19 having a transmission gear group 18 meshing with a transmission gear group 17 on the propulsion shaft 16 so as to be able to perform four-speed synchronous occlusion in the illustrated example. The main transmission 20 as a mission is configured.

A transmission shaft 23 of a shuttle transmission 22 is provided on the downstream side of the main transmission 20 (outside of the transmission shaft 19) via a hydraulic clutch 21 for inertia braking. Is the forward gear 24 and the reverse gear 2
5, the two gears 24, 25 can be freely turned on and off by a shifter 26. The output shaft of the shuttle transmission 22 also serves as the transmission shaft 28 of the auxiliary transmission 27. On this transmission shaft 28, the transmission gear 30 meshing with the reverse rotation gear 25 via the back gear 29 and the forward rotation transmission A gear 31 and a transmission gear 32 for high-speed sub-transmission are provided.

The counter shaft 33 of the auxiliary transmission 27 has a low-speed gear 34 that meshes with the gear 30 and a high-speed gear 35 that meshes with the gear 32, and has a shifter 36 that turns the two gears 34, 35 on and off. Here, the subtransmission 27 can be shifted up and down. The counter shaft 33 has a cylindrical shaft configuration. A transmission shaft 37 is inserted into the counter shaft 33, and the transmission shaft 37 is connected to the rear wheel differential device 3 via a coupling 38.
9 drive shaft 40.

A creep transmission 41 is disposed below the front side of the auxiliary transmission 27.
Reference numeral 1 denotes a first creep speed change which is provided with a first creep shaft 42 and a second creep shaft 43 and is interlocked with the transmission shaft 37 via a gear on the first creep shaft 42; A second creep shift interlocking with the transmission shaft 37 via a gear on the creep second shaft is enabled by turning on and off the shifter.

A front wheel drive unit 44 is disposed in front of the creep transmission 41 and below the main transmission 20.
The front wheel drive device 44 includes a clutch shaft 47 having a constant speed hydraulic clutch 45 and a speed increasing hydraulic clutch 46. The clutch shaft 47 is interlocked with a gear 48 on a transmission shaft 37. A front wheel drive shaft 49 is provided below, and the clutch shaft 47 and the front wheel drive shaft 49 are interlocked by front and rear interlocking gear groups 50 and 51, and the front wheel drive shaft 49 is interlocked with a front wheel differential device via a propulsion shaft 52. Have been.

The main transmission 20, the shuttle transmission 22, the auxiliary transmission 27, and the creep transmission 41 constitute a traveling system transmission. The transmission is transmitted to the device 39, the left and right rear wheels 3 can be driven from the left and right yoke shafts of the rear wheel differential device 39 via the final reduction gear, and the left and right front wheels 2 are disconnected together with the hydraulic clutches 45 and 46. The non-drive state (drive of only the rear wheels) and the hydraulic clutches 45 and 46
, The front wheel drive state synchronized with the rear wheel 3 and the so-called double speed front wheel drive state in which the speed is higher than that of the rear wheel 3 are possible.

A PTO transmission 53 is provided in front of the rear wheel differential device 39. The PTO transmission 53 is connected and disconnected by an independent PTO clutch 54 which is directly connected to the engine (in the figure, directly connected to the crankshaft 14). Therefore, the traveling propulsion shaft 16 and the speed change shaft 28 are both coaxial with each other to form a cylindrical shaft, and the PTO propulsion shaft (input shaft) 55 is attached to these cylindrical shafts 16 and 28. Have been interpolated.

The output of the PTO transmission 53 is connected to a transmission shaft 57 via a coupling 56, and the transmission shaft 57 is operatively connected to the PTO shaft 13 via a PTO reduction gear device 58. Is composed. Referring to FIG. 3 and FIG.
And the PTO transmission 53 will be described.

The independent PTO clutch 54 has a mounting coupling 57 for a clutch plate 56 on an input shaft 55 and a clutch housing 59 on an output shaft 58.
9 includes a hydraulic piston 61 that presses (clutches in) the clutch plate 56 by hydraulic pressure against the spring 60. The clutch housing 59 is provided with brake means 62, and the brake means 62
When 1 is returned by the spring 60 in the clutch disengagement direction, the brake means 62 acts in conjunction with this movement, and stops inertial idling at the time of switching from clutch engagement to disengagement. Provided.

Clutch output shaft (PTO shift input) 58
A drive gear 64 having an engaging portion 64A is engraved at the rear end, and a PTO speed change shaft 65 is installed coaxially with the clutch output shaft 58. The PTO speed change shaft 65 is connected to the PTO speed change shaft 65 via a coupling 56. The transmission shaft 57 is joined.
Outer splines 66A and 66B are formed on the PTO transmission shaft 65 so as to be divided into front and rear portions by a hollow portion 66C formed at an intermediate portion in the axial direction.
A shift gear 68 having inner splines 67A, 67B engaged with the gears A, 66B is fitted on the transmission shaft 65 so as to be slidable in the axial direction.

The shift gear 68 includes large and small gears 68A, 68B.
And the inner splines 67A, 67B
A hollow portion 67C is formed at an intermediate portion in the axial direction to partition the inner splines 67A and 67B forward and backward. A counter shaft 69 is provided in parallel with the PTO transmission shaft 65. The counter shaft 69 has a cylindrical structure, and is fitted around the differential drive shaft 40 so as to be relatively rotatable (slidable).

A transmission shaft 70 meshing with the drive gear 64 and transmission gears 71, P
Transmission gear 72 for first-speed TO and gear 7 for reverse rotation of PTO
3 is formed with a gap in the axial direction from the front to the rear, and a reverse gear 73 is engaged with an idle gear 75 provided on a back shaft 74. Shift gear 6
8, a shift fork (not shown) is engaged, and reciprocatingly slides from one side in the axial direction of the speed change shaft 65 along the other side as indicated by an arrow X, so that the PTO 3rd speed (3P) and the PTO 2nd speed (2P) , Neutral (NP), PTO 1st speed (1P), PTO
The gears can be shifted in the reverse rotation (PR) order (including the reverse order), and the shift gear 68 can be turned on and off in an I-type shift pattern.

More specifically, the PTO shift will be described. The position of the shift gear 68 shown in FIG.
And the large gear 68A of the shift gear 68 is the reverse gear 7
3 through an idle gear 75,
When the PTO clutch 54 is engaged (engaged), the transmission shaft 65 is driven in reverse rotation via the drive gear 64 → gear 70 → gear 73 → gear 75 → gear 68A, and the PTO shaft 13 is driven via the reduction gear 58. It is driven in reverse rotation and is used, for example, when the work machine 12 is an up-cut rotary.

In the case of the reverse rotation of the PTO, the shift gear 68
3 and 4, a thrust force is acting rearward (rightward in the figures), but the shift gear 68 is received by a wall such as a bearing, so that there is no shift loss. When the shift gear 68 is slid in the arrow X direction to the (IP) position, the large gear 68A of the shift gear 68 meshes with the transmission gear 72 to be in the first PTO speed, and at this time, the rear inner spline 67B of the shift gear 68 Since the front inner spline 67A of the shift gear 68 is in mesh with the rear outer spline 66B of the transmission shaft 65 and is not engaged with the hollow portion 66C of the transmission shaft 65, the thrust force of the shift gear 68 (in this case, the left side in FIG. ) Is reduced to prevent a shift loss.

Further, when the shift gear 68 is set to the (NP) position, the large and small gears 68A, 68B of the shift gear 68 do not mesh with any of the transmission gears 71, 72, and thus the transmission gears 71, 7 are not engaged.
When the shift gear 68 is set to the (2P) position from this state, the small gear 68B of the shift gear 68 meshes with the transmission gear 71, and the shift gear 68
The front inner spline 67A of the transmission gear 65 meshes with the front outer spline 66A of the transmission shaft 65, and the rear inner spline 67A of the shift gear 68.
Since B is not engaged with the hollowed portion 66C of the speed change shaft 65, the thrust force (acting on the left side in the figure) of the shift gear 68 is reduced, thereby preventing a shift loss.

That is, in the I-type shift pattern, when the shift gear 68 is at the shift position at an intermediate position in the axial direction of the shift shaft 65, one of the front and rear splines of the inner and outer splines is in the engaged state, so that the shift gear 68 is shifted. The dropout is prevented. Also, the shift gear 68
Is set to the (3P) position, the front inner spline 67A engages with the engaging portion 64A of the drive gear 64, and the output shaft 58 and the transmission shaft 6
5 is directly connected, and the PTO third speed is obtained. At this time, even if a thrust force on the left side of the figure acts on the shift gear 68, the drive gear 64 and the like act as a wall, so that there is no shift loss.

In the first to third speeds of the PTO, the PTO transmission shaft 65 is connected to the PT
It is obvious that the O-shaft 13 is driven, and on the condition that the pattern is an I-type shift pattern, the (PR), (IP), (NP),
(2P) and (3P) may be used. The hydraulic pump driving device according to the present invention will be described with reference to FIGS.

The hydraulic pump 80 to which the present invention is applied is provided on the upper surface of the tractor vehicle body 8, in FIG. 1, slightly in front of the hydraulic elevating device 10.
A pump 802 for the hydraulic elevating device 10 and a pump 803 for power steering are illustrated as a so-called series triple pump. A pump driving gear 82 is connected to a gear 81 on the input shaft 55 of the independent PTO clutch 54 via a relay gear 83. Are linked together.

Each of the pumps 801, 802, and 803 is a gear pump, and includes a driving gear 82 and a relay gear 83.
And a boss 8A of the tractor body 8 and a boss 84A of the pump case 84.
Is provided on the upper surface of the tractor body 8 by being detachably provided. The pumps 801 to 803 are provided with a starting pump gear 86 on a pump starting shaft 85, a driven pump gear 88 on a pump driven shaft 87, and supply ports 89A, 89B, 89C communicating with one of the engaging portions of the two gears 86, 88. A discharge port 90 is communicated with the other of the bite portions,
In the figure, gears 86 and 88 and a discharge port 90 are illustrated for the pump 801.

The hydraulic pump 80 includes pumps 802,
803, a dual pump of pumps 802 and 803 is provided with a pump 801 for the system.
Further, a shaft 85A for the pump 801 is coupled with a coupling 85B. The system pump 801 is used for relatively low-pressure system pressures such as the hydraulic clutch 21, the independent PTO clutch 54, and the hydraulic clutches 45 and 46 of the front wheel drive unit 44 described above.
4, 45 and 46 are connected to a discharge port 90 via a piping member via a piping member, so that system pressure can be supplied to each of the clutches 21, 54, 45 and 46 via each control valve. Have been.

The system pump 801 is provided with a relief valve 91 for relieving the system oil pressure. Oil discharged from the relief valve 91 is supplied to the drive gear 82 and the relay gear 83 via an oil passage 92. The lubricating oil can be supplied to the respective occlusal portions of the gear 81 and the oil, and the oil after lubricating the oil returns to the tank because the tractor body 8 substantially constitutes a hydraulic oil tank. ing.

Each of the supply ports 89A, 89B, 89
Although not shown, C is communicated (preferably provided with a filter) to the hydraulic oil tank via a supply piping member, and since the pump 80 is provided on the tractor body 8, the piping member is long. There is no need to make it.
Needless to say, hydraulic pressure can be supplied to the discharge ports of the pumps 802 and 803 to the respective control valves via piping members.
Is for steering the left and right front wheels 3.

As for the relief valve 91, the elasticity of the relief spring 91A shown in FIG. 7 can be adjusted by the screw adjuster 91B.

[0037]

As described in detail above, according to the present invention, PT
The hydraulic pump can be directly driven by the engine by the input shaft of the independent PTO clutch that constitutes the transmission of the O system, thereby preventing an increase in the length of the piping member and a reduction in the front wheel cut angle.

[Brief description of the drawings]

FIG. 1 is a side view of a tractor equipped with a hydraulic pump driving device according to the present invention.

FIG. 2 shows a P equipped with a hydraulic pump drive according to the invention.
FIG. 1 is an overall side view of a transmission including a TO transmission, which is partially developed.

FIG. 3 is a side view of the PTO transmission.

FIG. 4 is a sectional view of a main part of FIG. 3;

FIG. 5 is a partial sectional side view of the hydraulic pump driving device according to the present invention.

FIG. 6 is a front view of FIG. 5;

FIG. 7 is a sectional view taken along line XX of FIG. 6;

[Explanation of symbols]

 7 Engine 8 Tractor body 54 PTO clutch 55 PTO input shaft 80 Hydraulic pump 82 Pump drive gear

Claims (4)

[Claims] 1. A tractor hydraulic pump drive device comprising a hydraulic pump driven by an engine on an upper surface (upper part) of a tractor body, wherein a drive gear of the hydraulic pump is an independent PTO clutch in a PTO transmission. A hydraulic pump driving device for a tractor, which is linked to an input shaft of the tractor. 2. The tractor hydraulic pump drive device according to claim 1, wherein a relief valve is provided on the discharge side of the hydraulic pump, and the relief valve drains oil from a pump drive gear. 3. The tractor hydraulic pump drive device according to claim 2, wherein the relief valve is used for a system circuit of an independent PTO clutch and a front wheel drive hydraulic clutch. 4. The tractor hydraulic pump drive device according to claim 1, wherein the hydraulic pump comprises at least two hydraulic lift units and a power steering unit.