Coaxially mounted plunger type hydraulic power unit

Abstract

The present invention discloses a coaxially mounted plunger hydraulic power unit, comprising an intermediate body, a transmission shaft, and two plunger motors of identical structure symmetrically arranged on either side of the intermediate body. One end of the transmission shaft is connected to the cylinder body of one of the plunger motors, and the other end passes through the intermediate body and is connected to the cylinder body of the other plunger motor. The swash plate of the plunger motor is mounted on a side away from the intermediate body. The intermediate body is provided with a first oil port, a second oil port, and a third oil port. The axial plunger of one of the plunger motors is connected to the first oil port via a valve plate, the axial plunger of the other plunger motor is connected to the second oil port via another valve plate, and the third oil port is connected to the axial plungers of both plunger motors simultaneously via two valve plates. This application has the advantages of high synchronization accuracy, compact size, and strong adaptability to working conditions.

Description

Technical Field

[0001] The invention belongs to the technical field of hydraulic transmission, and in particular relates to a coaxially installed plunger type hydraulic power device. Background Art

[0002] Hydraulic transmission is widely used in engineering machinery, construction machinery, agricultural machinery, metallurgical machinery and other fields due to its high power density and stable operation. As machines continue to develop, the synchronous movement of multiple actuators is becoming more and more common, requiring synchronous control.

[0003] Currently, common synchronization circuits include throttling and positive displacement types. For example, throttling circuits employing flow-collecting and diverting valves offer an accuracy of 2%-5% and are inexpensive. Positive displacement synchronization circuits employ synchronous cylinders or synchronous motors / pumps. Synchronous gear motors, the most widely used positive displacement synchronization element, offer an accuracy of 1-3% when the actuator load pressure difference is small. However, if the actuator load pressure difference is large, the synchronization accuracy drops to 10-15%, which is insufficient for high-pressure differential synchronization circuits. Summary of the Invention

[0004] The main purpose of the present invention is to provide a coaxially mounted plunger type hydraulic power device with high synchronization accuracy, compact size and strong adaptability to working conditions.

[0005] To achieve the above objectives, this application adopts the following technical solutions:

[0006] A coaxially mounted plunger hydraulic power unit comprises an intermediate body, a transmission shaft, and two plunger motors of identical structure symmetrically arranged on both sides of the intermediate body;

[0007] One end of the transmission shaft is connected to the cylinder body of one of the plunger motors, and the other end passes through the intermediate body and is connected to the cylinder body of the other plunger motor. The swash plate of the plunger motor is installed on the side away from the intermediate body. The intermediate body is provided with a first oil port, a second oil port, and a third oil port.

[0008] The axial piston of one of the plunger motors is connected to the first oil port through a distribution plate, the axial piston of the other plunger motor is connected to the second oil port through another distribution plate, and the third oil port is connected to the axial pistons of the two plunger motors at the same time through the two distribution plates.

[0009] Specifically, the multiple axial pistons of the cylinder body abut against the inclined surface of the swash plate, the transmission shaft passes through the swash plate and is transmission-connected to the transmission hole of the cylinder body, the swash plate is fixedly connected to the motor housing of the plunger motor, and the motor housing is fixedly connected to the intermediate body.

[0010] Specifically, the plurality of axial pistons of the cylinder body are pressed against the swash plate via a return plate.

[0011] Specifically, the head of the axial piston has a sliding shoe, and the spring on the cylinder body presses the sliding shoe onto the swash plate through the return plate.

[0012] Specifically, the transmission shaft is mounted on the motor housing via a bearing.

[0013] Specifically, the axial plunger is arranged in the plunger hole of the cylinder body, the distribution plate is located between the cylinder body and the intermediate body, and the intermediate body is sealed with the cylinder body, so that the distribution plate is sealed with the cylinder body.

[0014] Specifically, the transmission shaft is a through shaft or a combination of multiple transmission shafts mechanically connected through shaft sleeves.

[0015] Specifically, the swash plate is fastened to the intermediate body via swash plate fixing screws.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1) the two symmetrically arranged plunger motors can realize the functions of a pump or a motor according to the working conditions. Compared with the gear synchronous motor, it has the advantages of high synchronization accuracy, compact size, and strong adaptability to working conditions; 2) the pressure of another oil port can be controlled by the pressure of the other two oil ports to achieve the purpose of increasing or reducing pressure; 3) the oil port is arranged on the middle intermediate body, the structure of the entire power unit is very compact, and the oil port processing is more convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 This is a structural diagram of a coaxially mounted plunger-type hydraulic power unit provided by an embodiment of the present invention;

[0019] Among them: 1-motor housing; 2-bearing; 3-swash plate; 4-slipper; 5-axial piston; 6-cylinder block; 7-intermediate body; 8-mounting bolt; 9-port plate; 10-drive shaft; Y1-first oil port; Y2-second oil port; Y3-third oil port. DETAILED DESCRIPTION

[0020] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0021] See also Figure 1 A coaxially mounted plunger hydraulic power unit comprises an intermediate body 7 and two plunger motors of identical structure symmetrically arranged on either side of the intermediate body 7; the cylinder bodies 6 of the two plunger motors are mechanically connected via a common transmission shaft 10 passing through the intermediate body 7; the swash plate 3 of the plunger motor is mounted on a side away from the intermediate body 7; the intermediate body 7 is provided with a first oil port Y1, a second oil port Y2, and a third oil port Y3, wherein;

[0022] The axial piston 5 of one plunger motor communicates with the first oil port Y1 via a port plate 9, while the axial piston 5 of the other plunger motor communicates with the second oil port Y1 via another port plate 9. The third oil port Y3 communicates with the axial pistons 5 of both plunger motors simultaneously via two port plates 9. The two port plates 9 are symmetrically arranged on either side of the intermediate body 7. The transmission shaft 10 can be a single through shaft or a combination of multiple transmission shafts mechanically connected via bushings.

[0023] See also Figure 1 Specifically, multiple pistons 5 of the cylinder block 6 of the plunger motor abut against the inclined surface of the swash plate 3. The swash plate 3 is penetrated by a through hole, which is coaxial with the transmission hole of the cylinder block 6. The transmission shaft 10 passes through the through hole of the swash plate 3 and is transmission-connected to the transmission hole of the cylinder block 6. The swash plate 3 is fixedly connected to the motor housing 1 of the plunger motor. The motor housing 1 is fixedly connected to the intermediate body 7 by mounting bolts 8. The transmission shaft 10 is mounted on the motor housing 1 through bearings 2.

[0024] The multiple plungers 5 of each cylinder body 6 are pressed against the swash plate 3 through the return plate. Specifically, each plunger 5 has a sliding shoe on its head, and the spring on the cylinder body 6 presses the sliding shoe against the swash plate 3 through the return plate.

[0025] See also Figure 1 The plunger 5 is arranged in the plunger 5 hole of the cylinder body 6, the distribution plate 9 is located between the cylinder body 6 and the intermediate body 7, the intermediate body 7 is sealed with the cylinder body 6, so that the distribution plate 9 is sealed with the cylinder body 6, and the swash plate 3 is fastened to the intermediate body 7 by the swash plate fixing screws.

[0026] See also Figure 1There are several axially arranged plunger holes evenly distributed on the cylinder body 6. The plunger 5 is installed in the plunger hole of the cylinder body 6. A slipper 4 is installed at the front end of the plunger and is pressed against the swash plate 3 by a spring. There are three oil ports on the intermediate body 7. The three pressure oil ports can be controlled on and off by adding a control valve. When the oil inlet and outlet pressures are different, the motor is driven to rotate. There is no output shaft at both ends of the power unit. The motor is driven to rotate through the combination of different pressures at the various oil ports of the intermediate body to achieve power conversion and transmission.

[0027] See also Figure 1 In this embodiment, the first and third oil ports Y1 and Y3 provided on the intermediate body 7 communicate with the left port plate 9. One port serves as an inlet for delivering high-pressure oil to the port plate 9. The port plate 9 transmits the hydraulic pressure of the high-pressure oil to the multiple plungers 5 within the cylinder 6, causing the multiple plungers 5 to rotate the cylinder 6. The other port serves as an outlet for discharging low-pressure oil from the port plate 9. The port plate 9 is provided with a high-pressure area and a low-pressure area. The high-pressure area is located near the inlet, and the low-pressure area is located near the outlet. Both the high-pressure area and the low-pressure area correspond to the multiple plungers 5. The pressure differential across the port plate 9 propels the multiple plungers 5 toward the swash plate 3, thereby counteracting the expansion and contraction motion of the multiple plungers 5 through the inclined surface of the swash plate 3. In a hydraulic motor or pump, the port plate 9 functions as a high-low oil distribution system, allowing the motor or pump to output torque when high-pressure oil is applied, and to discharge high-pressure oil from the cylinder 6 when it stops outputting torque when low-pressure oil (return oil) is applied. Similarly, the second oil port Y2 and the third oil port Y3 provided on the intermediate body 7 are both connected to the distribution plate 9 on the right side. As for the specific distribution process, it is the same as the above analysis process and will not be repeated here.

[0028] Compared to gear synchronous motors, this coaxially mounted plunger hydraulic power unit offers advantages such as high synchronization accuracy, compact size, and wide adaptability to operating conditions. Because the plunger motors are symmetrically arranged and have identical structures, this coaxially mounted plunger hydraulic power unit can also control the pressure of one oil port by controlling the pressure of the other two ports, achieving either pressure increase or pressure reduction.

[0029] The above embodiments are merely examples to clearly illustrate the present invention and are not intended to limit its implementation. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to provide an exhaustive list of all embodiments. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. Coaxially mounted plunger type hydraulic power unit, characterized by: It comprises an intermediate body (7), a transmission shaft (10), and two plunger motors of the same structure that are symmetrically arranged on both sides of the intermediate body (7); One end of the transmission shaft (10) is connected to the cylinder body (6) of one of the plunger motors, and the other end passes through the intermediate body (7) and is connected to the cylinder body (6) of the other plunger motor; The swash plate (3) of the plunger motor is installed on a side away from the intermediate body (7), and the intermediate body (7) is provided with a first oil port (Y1), a second oil port (Y2) and a third oil port (Y3); The axial piston (5) of one of the plunger motors is communicated with the first oil port (Y1) via a distribution plate (9), the axial piston (5) of another plunger motor is communicated with the second oil port (Y2) via another distribution plate (9), and the third oil port (Y3) is simultaneously communicated with the axial pistons (5) of the two plunger motors via two distribution plates (9); The three oil ports are connected by adding a control valve to achieve on-off control. When the oil pressure at the oil ports is different, the plunger motor is driven to rotate. There are no output shafts at either end of the power unit.

2. The coaxially mounted plunger type hydraulic power unit according to claim 1, characterized in that: The multiple axial pistons (5) of the cylinder body abut against the inclined surface of the swash plate (3); the transmission shaft (10) passes through the swash plate (3) and is transmission-connected to the transmission hole of the cylinder body (6); the swash plate (3) is fixedly connected to the motor housing (1) of the plunger motor; and the motor housing (1) is fixedly connected to the intermediate body (7).

3. The coaxially mounted plunger type hydraulic power unit according to claim 2, characterized in that: The plurality of axial pistons (5) of the cylinder body (6) are pressed against the swash plate (3) via a return plate.

4. The coaxially mounted plunger type hydraulic power unit according to claim 3, characterized in that: The head of the axial piston (5) is provided with a sliding shoe (4), and the spring on the cylinder body (6) presses the sliding shoe (4) onto the swash plate (3) via the return plate.

5. The coaxially mounted plunger type hydraulic power unit according to claim 2, characterized in that: The transmission shaft (10) is mounted on the motor housing (1) via a bearing (2).

6. The coaxially mounted plunger type hydraulic power unit according to claim 1, characterized in that: The transmission shaft (10) is a through shaft or a combination of multiple transmission shafts mechanically connected via shaft sleeves.

7. The coaxially mounted plunger type hydraulic power unit according to any one of claims 1 to 6, characterized in that: The axial piston (5) is arranged in the piston hole of the cylinder body (6), the distribution plate (9) is located between the cylinder body (6) and the intermediate body (7), and the intermediate body (7) is sealed with the cylinder body (6), so that the distribution plate (9) and the cylinder body (6) are sealed.

8. The coaxially mounted plunger type hydraulic power unit according to claim 7, characterized in that: The swash plate (3) is fastened to the intermediate body (7) via swash plate fixing screws.

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