JPH0437265Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to hydraulic rotating machinery, and in particular to axial plunger type hydraulic pumps and motors, and is suitable for use in working machines such as civil engineering and construction machinery. The present invention relates to something that can be effectively used as a drive source for mounted hydraulic equipment.

[Prior Art] A general axial plunger type hydraulic pump/motor has a rotating cylinder block, each cylinder block is formed in a direction parallel to the axis, and a communication hole is formed in each end face. A plurality of cylinder chambers, a piston fitted into each cylinder chamber so as to reciprocate, a valve plate having a pair of intake/exhaust ports, and a cylinder block and a cylinder block between the cylinder block and the valve plate. The valve plate includes a sub-plate that is arranged to integrally rotate and come into sliding contact with the end face of the valve plate, and a plurality of communication passages that are opened in the sub-plate so as to communicate the suction/exhaust ports and the communication hole. , by rotating the cylinder block while the sub-plate is in sliding contact with the valve plate, each cylinder is intermittently communicated with the suction/exhaust port, and the pump/motor action is performed by the reciprocating movement of the piston. There is something that happens. (For example, see Utility Model Publication No. 55-56212).

[Problem that the invention attempts to solve]

However, in such axial plunger type hydraulic pumps and motors, due to problems with machining accuracy, a gap occurs between the sub-plate and cylinder block end face from startup to extremely low speed rotation, so pressure oil leakage occurs, which tends to reduce the starting ability and smoothness of rotation of crane winches, etc.

An object of the present invention is to provide a hydraulic rotating machine that can prevent leakage of pressure oil.

[Means for solving problems]

The hydraulic rotating machine according to the present invention has a movable member fitted into each cylinder chamber with its position restricted so that a slight movement is allowed while maintaining a sealed state. It is characterized by having a communication hole that communicates with each communication path.

[Effect]

According to the above-described means, the movable member moves slightly during the action of the hydraulic pressure of the hydraulic rotary machine, thereby preventing a gap from occurring between the mating surfaces of the cylinder block and the sub-plate while maintaining the sealing state with respect to the cylinder chamber. In order to prevent this, leakage of pressure oil from between the cylinder chamber and the suction/exhaust port is prevented. The hydraulic rotary machine therefore performs hydraulic operations with high efficiency.

〔Example〕

Fig. 1 is a longitudinal cross-sectional view showing a hydraulic rotating machine which is an embodiment of the present invention, Fig. 2 is a partially omitted end view of a cylinder block taken along the - line in Fig. 1, and Fig. 3 is the same as Fig. 1. FIG. 4 is a partially omitted end view of the sub-plate taken along the - line in FIG. 1, and FIG. 5 is an enlarged partial cross-sectional view for explaining the operation. be.

In this embodiment, this hydraulic rotary machine is constructed as a hydraulic pump/motor and includes a casing 1 formed in a substantially cylindrical shape. A rotary shaft 2 is rotatably supported and installed on the axis of the casing 1 via a bearing. A cylinder block 3 formed in a substantially cylindrical shape is housed concentrically within the casing 1.
The cylinder block 3 is connected to the rotating shaft 2 via a spline 4 so as to rotate integrally therewith.

A plurality of cylinder chambers 5 are arranged around the rotation axis of the cylinder block 3 at equal intervals in the circumferential direction on the same radius, and are bored in a direction parallel to the axis.
Each cylinder chamber 5 is formed into a cylindrical hollow shape with both end faces open. A piston 7 is fitted into each cylinder chamber 5 from one open end so as to be able to reciprocate and slide freely.

A swash plate 8 is arranged and fixed at a position behind the piston fitting opening end of the cylinder chamber 5 in the casing 1 so as to be inclined at a predetermined angle with respect to the rotating shaft 2. The show 9 is
They are each held by a holding member 10 supported at one end of the cylinder block 3 and are slidably abutted thereon. A piston 7 is connected to each shoe 9 via a spherical joint 11,
As a result, each piston 7 is connected to the cylinder block 3.
When the cylinders rotate, they are reciprocated in the cylinder chamber 5.

An end plate 12 is brought into contact with the opposite side of the swash plate 8 of the casing 1 so as to close the end opening, and the end plate 12 has a first suction/exhaust passage 13 and a second suction/exhaust passage 14, respectively. .
A valve plate 15 formed in a substantially disk shape is disposed on the inner end surface of the end plate 12 with its one end surface closely attached and positioned by a pin 16. The end face of the cylinder block 3 on the closing wall side is pressed through a sub-plate (to be described later) under the bias of a compression spring 17 which is interposed in a state of storing force between the cylinder block 3 and the rotating shaft 2. being touched. In the valve plate 15, a first suction/exhaust port 18 and a second suction/exhaust port 19 are arranged symmetrically to each other on the same radius facing a group of communication passages opened in a sub-plate, which will be described later, to form a substantially semicircular arc shape. The first suction and discharge port 18 is connected to the first suction and discharge passage 13, and the second suction and discharge port 19 is connected to the second suction and discharge passage 14, respectively.

In each of the cylinder chambers 5, a movable member 20 formed in a substantially disk shape slightly smaller than the inner diameter of the cylinder chamber is fitted into an opening on the valve plate 15 side. Its position is regulated by a stopper ring 22 which is engaged with the inner circumferential surface of the cylinder chamber 5 so as to allow some movement relative to the cylinder chamber 5. In the movable member 20, a communication hole 21 as a part of a communication path is arranged on the axis and is opened to communicate the inside and outside of the cylinder chamber 5. A seal ring 23 formed of an elastic material is sandwiched between the cylinder chamber 5 and the cylinder chamber 5 so as to seal communication between the inside and outside of the cylinder chamber 5. Each movable member 20 includes a valve plate 15 and a cylinder block 3.
under the elastic force of the compression spring 17, the sub-plate 24 is connected to the cylinder block 3 by a pin 26 so as to rotate together with the cylinder block 3. By this,
It is adapted to slide against the valve plate 15. The sub-plate 24 has the same number of communication passages 25 as the cylinder chambers 5 arranged on the axial extension line of the cylinder chamber 5, and the cylinder block 3.
The communication path 25 is formed in an arc-shaped long hole concentric with the communication hole 21 of each movable member 20.
and both intake and exhaust ports 18 of the valve plate 15,
It is configured so that it can communicate with 19.

Next, the operation of the hydraulic pump/motor according to the above configuration as a hydraulic motor will be explained.

When attempting to rotationally drive the rotating shaft 2 in a desired direction, while the piston 7 moves from the top dead center to the bottom dead center, the cylinder chamber 5 is connected to the communication path between the communication hole 21 of the movable member 20 and the sub-plate 24. The swash plate 8, the cylinder block 3, and the valve plate 15 are connected to each other so as to communicate with the first suction/exhaust port 18 via the valve 25.
If a correlation such as
8, it will flow in through the communication path 25 and the communication hole 21.

Since the piston 7 is pressed by this high-pressure oil flowing into the cylinder chamber 5, the spherical joint portion 11 of the piston 7 is pressed against the swash plate 8 via the shoe 9. A component of this pressing force in the circumferential direction generates a torque that rotates the piston 7, that is, the cylinder block 3 supporting the piston. Since the torque for rotating the cylinder block 3 is transmitted to the rotating shaft 2 via the spline 4, the rotating shaft 2 is rotationally driven in a desired direction.

Then, as the cylinder block 3 rotates,
While the piston 7 moves from the bottom dead center to the top dead center,
The cylinder chamber 5 communicates with the pump second suction/discharge port 19 . At this time, the piston 7 is
As a result, the oil in the cylinder chamber 5 is discharged from the cylinder chamber 5 to the second suction and discharge passage 14 through the communication hole 21, the communication passage 25, and the second suction and discharge port 19.

In this way, the motor action is performed by repeating the flow of high-pressure oil into the cylinder chamber 5 and the discharge thereof from the cylinder chamber 5.

By the way, due to the following factors, gaps are generated between the cylinder block and the sub-plate, and between the sub-plate and the valve plate, and there is a risk that pressure oil may leak from the gaps.

(1) Machining or assembly errors regarding the perpendicularity between the rotation axis and the mating surfaces between the cylinder block and sub-plate.

(2) Error in the tooth trace in the spline between the rotating shaft and the cylinder block.

(3) Piston prying force.

(4) Error in flatness of mating surfaces between cylinder block, sub-plate, valve plate, and end plate.

However, in this embodiment, during motor operation,
The movable member 20 fitted into the opening on the valve plate 15 side of each cylinder chamber 5 moves slightly to absorb the gap formed between the cylinder block 3 and the sub-plate 24 for each cylinder chamber 5. In order to prevent the occurrence of a leakage path connecting the inside and outside of the cylinder chamber 5, the motor action is carried out with extremely high efficiency.

For example, as shown in FIG. 5, if the sub-plate 24 is inclined with respect to the plane perpendicular to the axis due to the accumulation of machining accuracy tolerances, the mating surface of the sub-plate 24 and the cylinder block 3 may be A gap occurs. However, the movable member 20 is regulated in position by a stopper ring 22 so as to be able to move slightly in the longitudinal direction in the cylinder chamber 5, and is held in the radial direction under the elastic force of a seal ring 23. The movable member 20 is connected to each cylinder chamber 5.
By receiving pressurized oil from
It will move slightly so that it is tilted with respect to the axis. Even if the movable member 20 moves slightly in this way, the seal ring 23 maintains the seal due to its elastic force. In other words, the movable member 20 is connected to the cylinder block 3.
The sub-plate 24 in each cylinder chamber 5 is absorbed by absorbing the gap generated between the sub-plate 24 and the
This ensures a close contact between the mating surfaces and a sealed state with respect to the inner circumferential surface of the cylinder chamber 5. As a result, even if a gap should occur between the cylinder block 3 and the sub-plate 24, leakage of pressure oil in each cylinder chamber 5 is reliably prevented. If leakage of pressure oil in each cylinder chamber 5 is prevented, the motor operation will be performed with extremely high efficiency.

The sub-plate 24 is connected to the valve plate 1 by each movable member 20 receiving the internal pressure of the cylinder chamber 5.
Since it is biased in the direction 5, it is brought into close contact with the valve plate 15, and the generation of a gap therebetween is prevented.

On the other hand, since the movable member absorbs errors in machining accuracy through its minute movements, the machining accuracy of each component can be relaxed, and as a result, productivity can be increased.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and may be modified without departing from the gist thereof.
It goes without saying that various changes are possible.

For example, the structure for holding the movable member so that it can move slightly is not limited to a structure that uses a stopper ring and a seal ring, but the movable member is baked into the opening of the cylinder chamber using an elastic material. It is also possible to use a structure in which the device is held in place.

Although the motor action has been explained in the above embodiment, the hydraulic rotating machine according to the above embodiment can be used not only for a swash plate type axial plunger type motor, but also for a swash plate type axial plunger type motor.
A pumping action can be performed. It can also be applied to an oblique axis type.

[Effect of idea]

As explained above, according to the present invention, leakage of pressure oil from each cylinder chamber can be prevented by slight movement of the movable member.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal cross-sectional view showing a hydraulic rotating machine which is an embodiment of the present invention, Fig. 2 is a partially omitted end view of a cylinder block taken along the - line in Fig. 1, and Fig. 3 is the same as Fig. 1. FIG. 4 is a partially omitted end view of the sub-plate taken along the - line in FIG. 1, and FIG. 5 is an enlarged partial cross-sectional view for explaining the operation. be. DESCRIPTION OF SYMBOLS 1... Casing, 2... Rotating shaft, 3... Cylinder block, 4... Spline, 5... Cylinder chamber, 7... Piston, 8... Swash plate, 9... Shu, 10... Holding member, 11... Spherical joint part, 1
2... End plate, 13... First suction/exhaust passage, 1
4...Second suction/exhaust passage, 15...Valve plate, 1
6... Pin, 17... Compression spring, 18... First intake/exhaust port, 19... Second intake/exhaust port, 20... Movable member, 21... Communication hole, 22... Stopper ring, 23... Seal ring, 24...Subplate, 25...Connection path, 26...Pin.

Claims (1)

[Scope of utility model registration request] A rotating cylinder block, a plurality of cylinder chambers each formed in the cylinder block in a direction parallel to its axis, a piston fitted into each cylinder chamber so as to reciprocate, and an end face of the cylinder block. A valve plate is provided, a pair of suction/exhaust ports are respectively opened in the valve plate, a sub-plate is interposed between the valve plate and the cylinder block so as to rotate together with the cylinder block, and In a hydraulic rotary machine, in which a plate and a cylinder block are provided with communication passages opened so as to communicate both suction/exhaust ports and each cylinder chamber, a movable member is provided in each cylinder chamber while maintaining a sealed state. 1. A hydraulic rotating machine characterized in that the movable members are fitted with their positions restricted to allow slight movement, and communication holes are provided in each movable member so as to communicate with the communication path.