JPS6238813Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a drive device for a hydraulic pump that pumps oil to a hydraulic clutch, and is particularly suitable for driving and stopping the PTO of work vehicles such as tractors regardless of whether the vehicle is running or stopping. This relates to a drive device for a hydraulic pump that pumps oil to the PTO clutch of an independent PTO.

Conventionally, in this type of pump drive device, a gear for driving the hydraulic pump is disposed on the input shaft of the PTO clutch, and when the engine rotates and the PTO clutch input shaft, which is directly connected to the engine, rotates, the hydraulic pump was always driven (1973-
(See Publication No. 60227). For this reason, even when PTO is not required, such as when the tractor is running or plowing, the hydraulic pump is constantly being driven, resulting in power loss.Especially in cold regions, the pump drive torque is reduced due to increased oil viscosity. This increase makes it difficult to start the engine, making it necessary to increase the capacity of the starting motor. In addition, even if a dedicated clutch is simply installed in the pump drive unit, the input member of the hydraulic PTO clutch is constantly rotating, so
Even when the PTO clutch is in a disengaged state, it is necessary to send lubricating and cooling oil to the clutch friction plate, etc., so it was not possible to simply provide a dedicated clutch to the pump drive section.

Therefore, the present invention has been developed for a work vehicle equipped with a hydraulic clutch for an independent PTO in which intermittent operation and friction plate lubrication and cooling are performed using pressure oil from a hydraulic pump for supplying lubricating oil and hydraulic oil. A gear is connected in series to an input member of the hydraulic clutch and a drive gear of the hydraulic pump, and a clutch is further provided to connect and disconnect power transmission between an input shaft that is linked to an engine and the input gear. However, it is an object of the present invention to provide a hydraulic pump drive device that can cut off the drive of the hydraulic pump when there is no need to drive the load via the hydraulic clutch.

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

1 is a transmission case of a tractor, and a PTO input shaft 2 directly connected to the engine and a clutch output shaft 3 serving as a PTO shaft are coaxially and rotatably supported on the case 1. A PTO clutch 5 is arranged between the shafts 2 and 3. A clutch 6 is slidably supported by a spline at the end of the input shaft 2, and an input gear 7 is rotatably supported at the tip thereof. Furthermore, the input gear 7 has a boss portion 7
A spline with which the clutch 6 can engage is formed on the spline a, and teeth 7b and internal splines 7c are formed on the outer periphery. Also, PTO clutch 5
The clutch is composed of a wet multi-plate hydraulic clutch and has a clutch body 9 fixed to the output shaft 3. A piston 10 is fitted into the main body 9, and a number of friction plates 11a are non-rotatably engaged with the main body 9, and a brake plate 13 provided on a plate 12 fixed to the case 1 slides on the outer periphery of the main body 9. This prevents the main body 9 from rotating continuously when the clutch is disengaged. Also,
An input member 15 is rotatably supported on the boss portion of the main body 9, and the member 15 is engaged with the internal spline 7c of the input gear 7, and a number of friction plates 11b are non-rotatably engaged. ing. In addition, 1 in the figure
6 is a pressure plate that presses the friction plates 11a and 11b by the piston 10, and 17 is a spring that normally biases the clutch to disconnect. An oil supply block 1 is connected to the output shaft 3.
Oil passages 20 and 21 are drilled through which the oil from the input shaft 2 communicates, and the oil passage 20 communicates with a cylinder chamber 22 formed by the piston 10. It is communicated with the friction plates 11a and 11b via a passage 23 as shown by the arrow, and lubricates and cools the friction plates. On the other hand, a hydraulic pump 25 is disposed in the mission case 1 and communicates with the oil supply block 19 via a pipe or the like, and a shaft 25a of the pump is engaged with a drive gear 27 via a drive shaft 26. Further, the drive gear 27 meshes with the teeth 7b of the input gear 7 via a counter gear 29.

Since this embodiment has the above configuration,
When using the PTO, move the clutch 6 in the direction of the arrow and engage the boss spline 7a of the input gear 7. In this state, the rotation of the engine is the input shaft 2.
and is transmitted to the input gear 7 via the clutch 6,
Furthermore, it is transmitted to the input member 15 of the PTO clutch 5 via the internal spline 7c, and the hydraulic pump 25 is driven via the counter gear 29, drive gear 27, and drive shaft 26. When the clutch is connected in this state, the switching valve (not shown) is switched, and the pressure oil from the pump 25 is sent to the cylinder chamber 22 via the oil supply block 19 and the oil passage 20, and the piston 10 is moved by the spring. 17
The rotation of the input member 15 is transmitted to the output shaft 3 via the clutch body 9 by moving against the friction plates 11a and 11b. In addition, when the clutch is in the disengaged state, the pressure oil from the pump 25 is transferred to the block 1.
9. Friction plates 11a, 11 via oil passages 21, 23
b, to lubricate and cool the friction plates that are sliding on each other.

When PTO is not required, such as when driving on the road, or when starting the engine, the clutch 6 is brought into a state where it is not engaged with the boss spline 7a of the input gear 7, as shown in the figure. In this state, the rotation of the input shaft 2 is not transmitted to the input gear 7, so
It is not transmitted to the input member 15 of the PTO clutch 5,
Moreover, the hydraulic pump 25 is also not driven.

As explained above, according to the present invention, the hydraulic clutch 5 for an independent PTO is provided in which the intermittent operation and the lubrication and cooling of the friction plates are performed by the pressure oil from the hydraulic pump 25 for supplying lubricating oil and hydraulic oil. In the work vehicle, an input gear 7 is connected in series to the input member 15 of the hydraulic clutch 5 and to a drive gear 27 of the hydraulic pump, and further includes an input shaft 2 interlocked with the engine and the input gear. Since a clutch 6 is disposed between the clutch 6 and the hydraulic clutch 7 to intermittent power transmission, if the hydraulic clutch 5 for independent PTO is required, by connecting the clutch 6, the hydraulic clutch 5 can be operated and its friction can be reduced. Board 11
a, 11b can be lubricated and cooled, and when it is not necessary to drive the load through the hydraulic clutch 5 for the independent PTO, the drive of the hydraulic pump is cut off to eliminate power loss, and the input member 15 of the hydraulic clutch 5 is By also cutting off the power transmission, it is possible to eliminate the sliding of the friction plates based on the rotation of the input side friction plate 11b, and to prevent problems such as heat generation of the friction plates even though the oil supply is cut off. In particular, since the hydraulic clutch 5 is an independent PTO clutch for work vehicles such as tractors, it improves work efficiency by eliminating power loss during pulling work such as plows that are subject to large loads, and also improves work efficiency when starting at low temperatures. The load on the motor can be reduced, and the capacity of a normal starting motor is sufficient even in cold regions.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a PTO clutch and a driving part of a hydraulic motor showing an embodiment of the present invention. 2...Input shaft, 3...Output shaft (PTO axis), 5...
... Hydraulic clutch (PTO clutch), 6 ... Clutch, 7 ... Input gear, 11a, 11b ... Friction plate, 15 ... Input member, 25 ... Hydraulic pump, 2
7... Drive gear.

Claims (1)

[Scope of utility model registration request] In a work vehicle equipped with a hydraulic clutch for an independent PTO in which intermittent operation and friction plate lubrication and cooling are performed using pressure oil from a hydraulic pump for supplying lubricating oil and hydraulic oil, the input gear is connected to the hydraulic clutch. A hydraulic pump drive comprising a clutch connected in series to an input member of the hydraulic pump, connected to a drive gear of the hydraulic pump, and further disposed between an input shaft interlocked with an engine and a clutch for intermittent power transmission between the input shaft and the input gear. Device.