JP2000314369A - Swash plate piston motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a swash plate piston motor of a hydraulic motor winch device which facilitates pay-off operation of a wire by eliminating friction between components of a swash plate piston motor. SOLUTION: A valve plate 7 is slidably arranged on an end face 3a of a cylinder block 3 located between the end face 3a of the cylinder block 3 and an end face 5a of a cover 5. A bush 9 with a spring is arranged so as to press the valve plate 7 inside the cover 5. In such a swash plate piston motor, a spool 12 is arranged, which has one side communicated with a passage in the cover 5 and slidably attached to a bush hole 13 formed on the cover 13 in a liquid tight manner, the other side loosely fitted to the cover 5, and a tip part attached to the valve plate 7. The valve plate 7 is moved by applying pressure oil to the spool 12, for keeping clearance between the cylinder block end surface and the end surface of the valve plate 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a swash plate type piston motor used for a hydraulic motor winch device and the like, and more particularly to a swash plate type piston motor configured to improve workability.

[0002]

2. Description of the Related Art Generally, in this type of hydraulic motor winch device, as shown in FIG. 2, pressure oil from a hydraulic pump 30 is supplied to a swash plate type piston motor 32 through an operation switching valve 31, and this motor 32 The load 3 is applied to the wire 36 through the reduction gear 33, the clutch 34, and the winch drum 35.
7 to be driven. In the hydraulic motor winch device having such a configuration, the wire 36 wound around the winch drum 35 separately from the original winch function.
Out to a predetermined place, and the work of connecting the load 37 to the wire 36 is required.

[0003]

The swash plate type piston motor used in such a hydraulic motor winch device has a frictional force between the shoe and the swash plate and between the cylinder block and the valve plate. A clutch 34 for turning on and off the driving of the winch drum 35 by the swash plate type piston motor 32 and the speed reducer 33 each time.
Therefore, the hydraulic motor winch device is large, the structure is complicated, and the cost is high.

[0004] The present invention has been made in view of the above points,
The purpose is to use the swash plate type piston motor and the cylinder block and valve plate in a swash plate type piston motor which is convenient for the wire feeding of a hydraulic motor winch device that can easily perform the original winch function and wire feeding work without providing a clutch. An object of the present invention is to provide a swash plate type piston motor which reduces frictional force between the swash plates.

[0005]

In order to achieve this object, a swash plate type piston motor according to the present invention comprises a drive shaft,
A cylinder block integrally coupled to the drive shaft and supporting a plurality of pistons slidably in the axial direction; a housing for rotatably housing the drive shaft; and a pressure on the piston by closing one end of the housing. A valve plate comprising a cover provided with a supply / discharge port for supplying / discharging oil, the valve plate being located between the end face of the cylinder block and the cover and slidably in contact with the end face of the cylinder block; In a swash plate type piston motor comprising a spring plate and a bush with a spring arranged so as to be in contact with the valve plate and press the valve plate in the cover, one side communicates with a passage formed in the cover and is engraved on the cover. A spoon mounted in a bush hole so as to be slidable in a liquid-tight manner, the other side of which is loosely fitted to the cover and the tip of which is attached to the valve plate. By applying pressure oil to the spool, the valve plate is moved to maintain a gap between the cylinder block end face and the valve plate end face to reduce the pressure acting on the valve plate end face. I do.

The swash plate type piston motor according to the present invention is inserted into one of the components in the structure of the conventional swash plate type piston motor, and one side thereof communicates with the passage so that the bush hole is formed. , And the other end is provided with a spool attached to the valve plate.

Accordingly, by applying pressure oil to the spool to move the valve plate to maintain a gap between the cylinder block end surface and the valve plate end surface, the shoe and swash plate generated in the swash plate type piston pomotor are provided. The frictional force between the cylinder block and the cylinder block and the valve plate can be reduced.

[0008]

Next, an embodiment of the present invention will be described with reference to FIG.
This will be described below. In general, as shown in FIG. 1, a swash plate type piston motor basically includes a drive shaft 1 and a plurality of pistons 2 which are formed integrally with the drive shaft 1 and driven, and are slidable in the axial direction. , A housing 4 for rotatably housing the drive shaft 1, and a housing 4 for rotatably supporting the cylinder block 3.
And a cover 5 for closing one end 5a. The piston 2 supported in the cylinder block 3 has its spherical surface portion 2a fitted to a shoe 7 provided in contact with a swash plate 6 fixed in the housing 4.

[0009] Between the end face 3a of the cylinder block 3 and the end face 5a of the cover 5, one end face 8a is connected to the end face 3a of the cylinder block 3 in a liquid-tight and slidable manner for connection therebetween. The contacting valve plate 8
The other end face 8b of the valve plate 8 is placed on one end face 5 in a liquid-tight manner.
When a is brought into contact with and pressed by a, it is performed by a spring-loaded bush 9 housed in the cover 5. A supply / discharge port 10 formed in the cover 5 supplies the hydraulic oil of a hydraulic pump (not shown) to the piston 2 through a hole 9 a of the bush 9 with spring and a hole 8 c of the valve plate 8.

A large diameter portion 12a of the spool 12 communicates with a passage 11 formed in the cover 5 so as to be slidably fitted in a bush hole 13 in a liquid-tight manner, and a small diameter portion 12b is loosely fitted in the cover 5. The tip of the valve plate 8 protrudes from the cover 5 so that the valve plate 8
It is fastened to. A blind lid 16 is attached to the cover 5 after the spool 12 is inserted into the bush hole 13.

Next, the operation of the swash plate type piston motor will be described. Pressure oil supplied to a pressure oil port 14 connected to a pressure source (not shown) is supplied to a spool 1 via a passage 11.
Acting on the large-diameter portion 12a of FIG. 2, the spool 12 starts rightward in the figure against the spring force of the bush 9 with spring. One end face 8 of the valve plate 8 interlocks with the movement of the spool 12.
a is separated from the end face 3a of the cylinder block 3, a gap is created between these end faces 3a and 8a, and the liquid-tight contact is released.

For this reason, the frictional force between the swash plate 6 and the shoes 7 attached to the return plate 17 by the spring 15 and the frictional force between the end surface 3 of the cylinder block and the end surface of the valve plate 8 by the bush 9 with spring are reduced. Therefore, for example, when the wire 36 wound around the winch drum 35 is fed, the wire 36 can be fed while the frictional force in the swash plate type piston motor is reduced. The swash plate type piston motor of this embodiment has been described with respect to the case of a winch device used for a crane such as a construction machine, but in a swivel device of a crane such as a construction machine, the center of the crane in the lifting work is extended to the center of the lifting load. When it is moved, it can also be used for the turning operation of the turning device when the crane is moved via the lifting load.

[0013]

According to the present invention, the frictional force caused by the spring force in the structure of the swash plate type piston motor can be reduced by mechanically separating the valve plate from the end of the cylinder block. The work of feeding the bridged wire is facilitated, and the load on the operator is reduced. Further, since the valve plate also serves as a detent, a clutch is not required and the cost is low, and a wire pulling mechanism of a compact winch device can be provided.

[Brief description of the drawings]

FIG. 1 is an overall structural view of a swash plate type piston motor showing an embodiment of the present invention.

FIG. 2 is a schematic view of a hydraulic motor winch device used for a crane such as a construction machine.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Drive shaft 2 Piston 2a Spherical part 3 Cylinder block 3a 5a 8a 8b End face 4 Housing 5 Cover 5a One end face 6 Swash plate 7 Shoe 8 Valve plate 8c 9a Hole 9 Spring-loaded bush 10 Supply / discharge port 11 Passage 12 Spool 12a Large diameter section 12b Small diameter portion 13 Bush hole 14 Pressure oil port 15 Spring 16 Blind lid 17 Return plate 30 Hydraulic pump 31 Operation switching valve 32 Swash plate type piston motor 33 Reduction gear 34 Clutch 35 Winch drum 36 Wire 37 Load

Claims (2)

[Claims] 1. A drive shaft, a cylinder block integrally connected to the drive shaft and supporting a plurality of pistons slidably in an axial direction, a housing for rotatably housing the drive shaft, and one end of the housing And a cover provided with a supply / discharge port for supplying / discharging the pressure oil to / from the piston, and slides on the end surface of the cylinder block between the end surface of the cylinder block and the cover. In a swash plate type piston motor comprising a valve plate freely contacting and a spring-loaded bush arranged to press against the valve plate in the cover while being in contact with the valve plate, a passage formed in the cover on one side. And a sprung which is slidably mounted in a liquid-tight manner in a bush hole formed in the cover, the other side of which is loosely fitted to the cover and which is attached to the valve plate. The valve plate is moved by applying pressure oil to the spool to maintain the gap between the cylinder block end face and the valve plate end face, thereby reducing the pressure acting on the valve plate end face. Swash plate type piston motor. 2. The spool has a large-diameter portion connected to a passage provided in the cover and fitted into a bush hole, a small-diameter portion loosely fitted to the cover, and a tip portion protruding from the cover and attached to a valve plate. The swash plate type piston motor according to claim 1, wherein