An oil makeup pump for a closed system

Abstract

The utility model provides a kind of oil supplementing pump for closed system, including outer rotor and inner rotor;The outer rotor sleeve is connected in the outer portion of inner rotor, forms cycloidal internal meshing gear pair;The inner rotor is connected with oil supplementing pump coupling by semicircle key, and oil supplementing pump coupling is connected with spline of axial plunger bidirectional variable volume pump drive shaft;The outer rotor sleeve is connected with outer ring, and the both ends of outer rotor are connected with oil distribution cover and wear plate respectively;The oil supplementing pump coupling inner sleeve is connected with coupling, and outer ring is embedded in the rear cover of axial plunger bidirectional variable volume pump;Oil suction port and oil discharge hole are equipped on the wear plate, and the tooth profile of outer rotor and inner rotor is engaged to form multiple closed working cavities.The utility model outer rotor tooth number is less, and high-low pressure chamber does not use isolation element simultaneously, and it is compact in structure, small in size, light in weight and simple in structure;It has independent coupling, can adjust the parameter of coupling to make axial plunger bidirectional variable volume pump after string different pump.

Description

Technical Field

[0001] This utility model relates to a replenishing pump for a closed system, which is suitable for use in a high-pressure axial piston bidirectional variable pump in a closed system. It has high versatility and wide application. Background Technology

[0002] A hydraulic system is a power transmission system that uses fluid pressure to transmit energy and achieve force and motion control. It mainly consists of hydraulic components, actuators, control components, hydraulic power sources, and auxiliary components.

[0003] A closed-loop hydraulic system is a self-contained fluid power transmission system. Unlike an open-loop hydraulic system, a closed-loop hydraulic system places the hydraulic oil in a completely closed circuit, recycles the oil, and uses pressure control methods to complete the energy conversion and transmission of hydraulic power.

[0004] Closed-loop hydraulic systems are widely used in various fields, such as industrial fields like excavators, railway locomotives, automobile manufacturing, aircraft manufacturing, and metal processing, as well as civilian fields like ships and airports. They play an irreplaceable role, especially in large-scale machinery and equipment.

[0005] In summary, closed-loop hydraulic systems, as a highly efficient, energy-saving, flexible, and reliable power transmission system, are gradually becoming an indispensable part of people's production and daily life.

[0006] In closed-loop hydraulic systems, the replenishing pump is a crucial component. Because the hydraulic fluid circulates internally within a closed system and doesn't draw oil from the tank, the oil temperature is high, heat dissipation is poor, and hydraulic components suffer efficiency losses. Leaks in the piping can also cause the axial piston variable displacement pump to cavitate, ultimately leading to its failure. The replenishing pump's function is to replenish oil to the closed system, pressurize the inlet of the axial piston variable displacement pump to improve its suction capacity, and provide cooled oil to the closed-loop hydraulic system for heat dissipation. Therefore, designing a replenishing pump for a closed-loop hydraulic system is of great significance in improving its stability and reliability.

[0007] In existing technologies, the replenishing pump of a closed system is generally connected in series with an external gear pump after the axial piston bidirectional variable pump, resulting in a large overall size of the closed system. Alternatively, an involute internal gear pump is embedded in the rear cover of the axial piston bidirectional variable pump, which is complex to combine, has poor machinability, high cost, and poor high-speed performance. Utility Model Content

[0008] To solve the above-mentioned technical problems, this utility model provides a replenishing pump for a closed system. The replenishing pump for a closed system adopts a cycloidal internal gear pump, which has a simple structure, good processing performance, compact size, and good working characteristics.

[0009] This utility model is achieved through the following technical solution.

[0010] This utility model provides an oil replenishment pump for a closed system, comprising an outer rotor and an inner rotor; the outer rotor is sleeved outside the inner rotor to form a cycloidal internal meshing gear pair; the inner rotor is connected to an oil replenishment pump coupling via a semi-circular key, and the oil replenishment pump coupling is splinedly connected to the drive shaft of an axial plunger bidirectional variable pump; an outer ring is sleeved on the outer rotor, and an oil distributor cap and a wear-resistant disc are respectively connected to both ends of the outer rotor; a coupling is sleeved inside the oil replenishment pump coupling, and the outer ring is embedded in the rear cover of the axial plunger bidirectional variable pump; the wear-resistant disc is provided with an oil suction port and an oil discharge hole, and the meshing of the tooth profiles of the outer rotor and the inner rotor forms multiple sealed working chambers.

[0011] The rated speed of the axial piston bidirectional variable pump is 3300 r / min, the maximum speed is 3650 r / min, the rated pressure is 45 MPa, and the peak pressure is 48 MPa.

[0012] The outer ring, oil distributor cap, and wear-resistant disc are fixedly connected by locating pins.

[0013] The locating pin is fixed inside the rear cover of the axial piston bidirectional variable pump.

[0014] The outer rotor is an internal gear with 13 teeth.

[0015] The inner rotor is an external gear, which is also the driving gear, and has 12 teeth.

[0016] No isolation element is provided between the oil separator cover and the outer rotor.

[0017] A DU bearing is provided between the oil distributor cap and the oil replenishment pump coupling.

[0018] The number of sealed working chambers is the same as the number of teeth on the outer rotor.

[0019] An eccentricity e is provided between the center of the inner rotor and the center of the outer rotor.

[0020] The advantages of this utility model are: fewer teeth on the inner and outer rotors, no isolation elements required for the high and low pressure chambers, compact structure, small size, light weight, and simple structure; it has an independent coupling, and the parameters of the coupling can be adjusted to allow different pumps to be connected in series after the axial piston bidirectional variable pump. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 yes Figure 1 Longitudinal cross-sectional view a; Figure 3 yes Figure 1 Longitudinal cross-sectional view b; Figure 4 This is a schematic diagram of the inner and outer rotors of this utility model; In the diagram: 1-Coupling, 2-Wear-resistant disc, 3-Positioning pin, 4-Maintenance pump coupling, 5-Half-circular key, 6-DU bearing, 7-Oil distributor cap, 8-Outer rotor, 9-Inner rotor, 10-Outer ring. Detailed Implementation

[0022] The technical solution of this utility model is further described below, but the scope of protection is not limited to what is described.

[0023] like Figures 1-4 As shown, the inner rotor 9 is an external gear with 12 teeth, and the outer rotor 8 is an internal gear with 13 teeth; the inner rotor 9 is the driving wheel, and there is an eccentricity e between its center and the center of the outer rotor 8.

[0024] Specifically, the inner rotor 9 is connected to the oil replenishing pump coupling 4 via a semi-circular key 5. The oil replenishing pump coupling 4 is connected to the spline of the drive shaft of the axial plunger bidirectional variable pump. Due to the meshing of the tooth profiles of the inner and outer rotors, a sealed working cavity with the same number of teeth as the outer rotor 8 is formed. When the axial plunger bidirectional variable pump rotates clockwise, it drives the oil replenishing pump coupling 4 to drive the inner rotor 9 to rotate clockwise. The outer rotor 8 rotates in the same direction as the inner rotor 9. When it rotates to the oil suction cavity, the volume of the sealed working cavity formed by the tooth tips of the inner rotor 9 and the tooth tips of the outer rotor 8 gradually increases due to the speed difference between the inner and outer rotors 8, forming a vacuum, and oil is drawn from the oil suction port on the wear-resistant disc 2. When it rotates to the oil discharge cavity, the sealed working cavity gradually decreases, thus forming the oil discharge process.

[0025] Furthermore, when the outer rotor 8 rotates one revolution, each sealed working chamber draws in and discharges oil once.

[0026] Specifically, the positioning pin 3 fixes the outer ring 10, the oil distribution cover 7, and the wear-resistant disc 2 together. The positioning pin 3 is fixed in the rear cover of the axial piston bidirectional variable pump and is positioned by the outer ring 10 embedded in the rear cover. The oil replenishment pump is connected to the spline of the drive shaft of the axial piston bidirectional variable pump through the oil replenishment pump coupling 4, so that the entire oil replenishment occupies very little space in the closed system.

[0027] Preferably, the replenishing pump also includes a coupling 1. This coupling can be removed when a tandem pump is not needed and added when a tandem pump is required. The parameters of the coupling 1 can be adjusted according to the spline parameters of the tandem pump. Furthermore, the coupling 1 is directly connected to the axial piston bidirectional variable pump. In this way, the force of the tandem pump is directly transmitted to the axial piston bidirectional variable pump, rather than acting on the replenishing pump, which can improve the reliability of the replenishing pump.

Claims

1. A make-up oil pump for a closed system, comprising an outer rotor (8) and an inner rotor (9), characterized in that: The outer rotor (8) is sleeved on the outside of the inner rotor (9) to form a cycloidal internal meshing gear pair; the inner rotor (9) is connected to the oil replenishing pump coupling (4) through a semi-circular key (5), and the oil replenishing pump coupling (4) is splined to the drive shaft of the axial plunger bidirectional variable pump; the outer rotor (8) is sleeved with an outer ring (10), and the two ends of the outer rotor (8) are respectively connected to an oil distribution cover (7) and a wear-resistant disc (2); the oil replenishing pump coupling (4) is sleeved with a coupling (1), and the outer ring (10) is embedded in the rear cover of the axial plunger bidirectional variable pump; the wear-resistant disc (2) is provided with an oil suction port and an oil discharge hole, and the tooth profiles of the outer rotor (8) and the inner rotor (9) mesh to form multiple sealed working chambers.

2. The make-up oil pump for a closed system as described in claim 1, characterized in that: The rated speed of the axial piston bidirectional variable pump is 3300 r / min, the maximum speed is 3650 r / min, the rated pressure is 45 MPa, and the peak pressure is 48 MPa.

3. The make-up oil pump for a closed system as described in claim 1, characterized in that: The outer ring (10), the oil distribution cap (7) and the wear-resistant disc (2) are fixedly connected by a positioning pin (3).

4. The make-up oil pump for a closed system as described in claim 3, characterized in that: The positioning pin (3) is fixed in the rear cover of the axial piston bidirectional variable pump.

5. The make-up oil pump for a closed system as described in claim 1, characterized in that: The outer rotor (8) is an internal gear with 13 teeth.

6. The make-up oil pump for a closed system as described in claim 1, characterized in that: The inner rotor (9) is an external gear and also a driving gear, with 12 teeth.

7. The make-up oil pump for a closed system as described in claim 1, characterized in that: No isolation element is provided between the oil separator cover (7) and the outer rotor (8).

8. The make-up oil pump for a closed system as described in claim 1, characterized in that: A DU bearing (6) is provided between the oil distribution cover (7) and the oil replenishment pump coupling (4).

9. The make-up oil pump for a closed system as described in claim 1, characterized in that: The number of the sealed working chambers is the same as the number of teeth of the outer rotor (8).

10. The make-up oil pump for a closed system as described in claim 1, characterized in that: An eccentricity e is provided between the center of the inner rotor (9) and the center of the outer rotor (8).

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