An energy recovery device and method based on the flow distribution and pressure relief stage of a swash plate axial piston pump

Abstract

The present invention discloses an energy recovery device and method for the flow distribution and pressure relief phase of a swash plate axial piston pump. Unlike conventional flow distribution plates, which connect a recovery hole with the interior of the pump housing, allowing the plunger to discharge high-pressure oil into the housing cavity during pressure relief, the present method connects the recovery hole with a recovery chamber, allowing the high-pressure oil discharged during the plunger unloading process to be recovered in the chamber. Whenever the plunger enters the oil intake phase, the high-pressure oil stored in the chamber is returned to the plunger cavity through the recovery hole for pressure compensation, thereby achieving energy recovery and reuse during the flow distribution process.

Description

Technical Field

[0001] The present invention relates to an energy recovery method in the flow distribution and pressure relief stage of a swash plate axial piston pump, and in particular to an energy recovery device and method based on the oil suction pressure compensation of the swash plate axial piston pump. Background Art

[0002] Swash plate axial piston pumps are the power components of hydraulic systems. Due to their compact size, simple structure, and high power density, they are widely used in engineering fields such as machine tool forging, metallurgy, engineering, mining, and shipbuilding. Cavitation is a negative phenomenon that occurs during pump operation, often occurring during the oil suction phase and the initial pressure switching phase. It not only shortens the pump's lifespan but also increases pump noise, directly leading to a decrease in pump performance. Summary of the Invention

[0003] In order to reduce the negative impact of cavitation on the swash plate axial piston pump, the present invention provides an energy recovery and pressure compensation method based on the flow distribution and pressure relief stage. This method can weaken or even eliminate the cavitation of the plunger in the early stage of oil suction, which has important engineering significance for improving the service life of the swash plate axial piston pump and reducing the working noise.

[0004] The technical solution adopted in the present invention is as follows:

[0005] The present invention includes a distribution plate and a rear end cover. A recovery hole group, an oil supply groove, and a distribution plate recovery flow channel are provided in the pressure relief transition zone of the distribution plate, wherein the recovery hole group is composed of multiple recovery holes, the oil supply groove is connected with the recovery hole closest to the oil suction waist groove, and all the recovery holes are connected with the distribution plate recovery flow channel; a rear end cover recovery flow channel is provided on the surface of the contact position between the rear end cover and the distribution plate recovery flow channel, a recovery cavity is provided inside the rear end cover, and the rear end cover recovery flow channel is connected with the recovery cavity.

[0006] The pressure relief transition zone of the valve plate is provided with a set of recovery holes and an oil replenishment groove. A valve plate recovery channel is provided at the bottom of the pressure relief transition zone. The recovery holes are connected to the valve plate recovery channel, and the oil replenishment groove is connected to the set of recovery holes. To reduce pressure loss, the flow area of the valve plate recovery channel should be as large as possible.

[0007] The rear end cover is provided with a rear end cover recovery flow channel and a recovery cavity. The rear end cover recovery flow channel is opened at the contact position between the rear end cover and the recovery flow channel at the bottom of the distribution plate. The recovery cavity is opened inside the rear end cover. The rear end cover recovery flow channel is connected to the internal recovery cavity.

[0008] When the distribution plate is installed on the rear end cover, the distribution plate recovery flow channel is connected to the rear end cover recovery flow channel, and the recovery hole group is connected to the recovery cavity through the distribution plate recovery flow channel.

[0009] The high-pressure oil discharged during the plunger pressure relief process enters the recovery chamber through the recovery hole group, the distribution plate recovery flow channel, and the rear end cover recovery flow channel. When the plunger enters the oil suction stage, the oil in the recovery chamber flows into the plunger through the recovery hole group and the oil replenishment groove to compensate for its pressure. The oil replenishment groove can extend the connection time between the plunger cavity and the recovery chamber, thereby maximizing the pressure compensation effect.

[0010] In the structure of the present invention, the pressure of the oil suction plunger is compensated by recovering the high-pressure oil discharged during the plunger pressure relief process, thereby reducing / eliminating the negative impact of cavitation. The pressure compensation effect is positively correlated with the load of the axial piston pump. The greater the load pressure, the better the effect.

[0011] The present invention has the following beneficial effects:

[0012] The present invention can realize energy recovery and reuse in the internal flow distribution process of the swash plate axial piston pump, perform pressure compensation on the plunger in the initial stage of oil suction, and suppress the occurrence of cavitation, thereby improving the service life of the swash plate axial piston pump and reducing operating noise.

[0013] The present invention is different from the traditional distribution plate that connects the recovery hole with the inside of the pump housing, so that the high-pressure oil is discharged into the inner cavity of the housing when the plunger is relieved. The method of the present invention connects the recovery hole with a recovery chamber, so that the high-pressure oil discharged during the plunger unloading process is recovered into the chamber. Whenever the plunger enters the oil suction stage, the high-pressure oil stored in the chamber returns to the plunger cavity through the recovery hole again, and its pressure is compensated, thereby realizing energy recovery and reuse in the distribution process. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a working principle diagram of an embodiment of the present invention.

[0015] Figure 2 This is the external structure diagram of the rear end cover.

[0016] Figure 3 This is a structural diagram of the recovery cavity inside the rear end cover.

[0017] Figure 4 It is a front structural diagram of the distribution plate of the present invention.

[0018] Figure 5 This is a partial structural diagram of the distribution plate recovery hole group and the oil replenishment groove of the present invention.

[0019] Figure 6 This is a partial structural diagram of the distribution plate recovery hole, oil replenishment groove and recovery flow channel of the present invention.

[0020] Figure 7 It is a perspective view of the three-dimensional structure of the distribution plate of the present invention.

[0021] Figure 8This is the structural diagram of the traditional distribution plate.

[0022] Figure 9 This is a diagram of the cylinder structure.

[0023] Figure 10 It is a cross-sectional view of the plunger cavity inside the cylinder.

[0024] Table 1 is a comparison table of multi-operating condition data of an embodiment of the present invention.

[0025] In the figure: 1. distribution plate, 2. distribution plate recovery flow channel, 3. recovery hole group, 4. oil supply groove, 5. rear end cover recovery flow channel, 6. recovery chamber, 7. rear end cover, 8. plunger chamber, 9. plunger chamber distribution window, 10. pressure relief hole (connected to the inside of the shell), 11. oil suction waist groove, 12. boost transition zone, 13. oil discharge waist groove, 14. pressure relief transition zone, 15. pressure relief hole group, 16. cylinder body, 3-1. recovery hole I, 3-2. recovery hole II, 3-3. recovery hole III, 3-4. recovery hole IV. DETAILED DESCRIPTION

[0026] The present invention will be further described below with reference to the accompanying drawings and examples.

[0027] like Figure 1 As shown, the main components of the method of the present invention include a distribution plate 1 and a recovery chamber 6. The surface of the pressure relief transition zone of the distribution plate 1 is provided with a recovery hole group 3 and an oil replenishing groove 4. The bottom of the pressure relief transition zone of the distribution plate is provided with a distribution plate recovery flow channel 2. The recovery hole group 3 is connected to the recovery chamber 6.

[0028] like Figure 2 and Figure 3 As shown, the rear end cover 7 defines a rear end cover recovery channel 5 and a recovery chamber 6. The rear end cover recovery channel 5 and the recovery chamber 6 are connected and located where the rear end cover contacts the recovery channel of the distribution plate. The recovery chamber 6 is integrated into the unused physical space within the rear end cover and is filled with the recovery chamber 6.

[0029] like Figure 4 、 Figure 5 、 Figure 6 and Figure 7 As shown, the distribution plate of the present invention mainly includes a distribution plate recovery flow channel 2, a recovery hole group 3, an oil supply groove 4, a pressure relief hole 10, an oil suction waist groove 11, a pressure boost transition zone 12, an oil discharge waist groove 13, and a pressure relief transition zone 14, wherein the oil supply groove 4 is connected to the recovery hole IV3-4, the recovery hole group 3 is connected to the recovery chamber 6 through the distribution plate recovery flow channel 2, and the pressure relief hole 10 is connected to the inside of the pump casing.

[0030] like Figure 8As shown, the traditional distribution plate mainly includes an oil suction waist groove 11, a pressure boost transition area 12, an oil discharge waist groove 13, a pressure relief transition area 14, and a pressure relief hole group 15, wherein the pressure relief hole group 15 is connected to the inside of the pump housing.

[0031] like Figure 9 、 Figure 10 As shown, the cylinder body 16 includes a plunger cavity 8 and a plunger distribution window 9 . The plunger distribution window 9 is provided on a surface that matches the distribution plate 1 and is communicated with the plunger cavity 8 .

[0032] The working principle of the present invention to achieve energy recovery and pressure compensation in the flow distribution and pressure relief stage is as follows:

[0033] like Figure 1 、 Figure 4 and Figure 5 As shown, on the one hand, four recovery holes are opened on the surface of the pressure relief transition zone of the distribution plate 1, namely recovery hole I3-1, recovery hole II3-2, recovery hole III3-3, and recovery hole IV3-4, which together constitute the recovery hole group 3. At the same time, a distribution plate recovery flow channel 2 is opened at the bottom of the pressure relief transition zone, and the recovery hole group 3 is connected to the distribution plate recovery flow channel 2; on the other hand, a rear end cover recovery flow channel 4 is opened at the contact position between the rear end cover 7 and the distribution plate recovery flow channel 2, and a recovery cavity 6 is opened inside the rear end cover 7, and the rear end cover recovery flow channel 4 is connected to the recovery cavity 6. When the plunger cavity distribution window 9 is connected to the recovery hole group 3, the high-pressure oil discharged by the plunger during pressure relief enters the recovery chamber 6 through the recovery hole group 3, the distribution plate recovery flow channel 2, and the rear end cover recovery flow channel 4. When the plunger enters the oil suction stage, the high-pressure oil in the recovery chamber 6 enters the plunger cavity through the rear end cover flow channel 5, the distribution plate recovery flow channel 2, the recovery hole group 3 and the oil replenishment groove 4 to compensate for its pressure, thereby realizing energy recovery and reuse in the distribution process.

[0034] This embodiment was simulated and verified. A traditional valve plate and a valve plate with a pressure relief energy recovery system were simulated respectively. The internal pressure of the plunger during the oil suction stage under different working conditions was compared. The results are shown in Table 1.

[0035] Table 1 Simulation results of traditional valve plate and valve plate with pressure relief energy recovery system

[0036]

[0037] From the above results, it can be seen that the distribution plate of the present invention can effectively reduce the cavitation risk in the initial stage of oil suction in the plunger cavity compared with the traditional distribution plate, and improve the working performance of the axial piston pump.

Claims

1. An energy recovery device based on the flow distribution and pressure relief stage of a swash plate type axial piston pump, comprising a flow distribution plate (1), a rear end cover (7), a plunger cavity (8), a plunger cavity flow distribution window (9) and a cylinder body (16), wherein the flow distribution plate (1), the rear end cover (7) and the cylinder body (16) are coaxially mounted, wherein: The distribution plate (1) is located between the rear end cover (7) and the cylinder body (16), and contacts the rear end cover (7) and the cylinder body (16) respectively. The plunger cavity (8) is opened in the cylinder body (16). The plunger cavity distribution window (9) is opened on the surface where the cylinder body (16) and the distribution plate (1) match, and is communicated with the plunger cavity (8). It is characterized in that: The distribution plate (1) is provided with a distribution plate recovery flow channel (2), a recovery hole group (3), and an oil supply groove (4); the recovery hole group (3) is composed of a plurality of recovery holes arranged in the distribution plate pressure relief transition zone, the oil supply groove (4) is arranged in the distribution plate pressure relief transition zone and close to the distribution plate oil suction waist groove (11), and the recovery hole group (3) and the oil supply groove (4) are located on the end surface of the distribution plate (1) in contact with the cylinder body (16); A recovery chamber (6) and a recovery flow channel (5) are provided in the rear end cover (7). The recovery chamber (6) is integrated into an unused physical space inside the rear end cover (7). The recovery flow channel (5) of the rear end cover is located on an end surface where the rear end cover (7) and the distribution plate (1) cooperate. The recovery flow channel (5) of the rear end cover is communicated with the recovery chamber (6). The distribution plate recovery flow channel (2) is opened at the bottom of the pressure relief transition zone of the distribution plate (1), one end of which is connected to the recovery hole group (3). When the distribution plate (1) and the rear end cover (7) are coaxially installed, the other end of the distribution plate recovery flow channel (2) is connected to the rear end cover recovery flow channel (5); All recovery holes are connected to the distribution plate recovery channel (2); One of the recovery holes is arranged near the end of the oil suction waist groove (11) of the distribution plate, and the recovery hole arranged near the oil suction waist groove is communicated with the oil replenishment groove (4), and the oil replenishment groove (4) is an arc-shaped sink.

2. The energy recovery device based on the flow distribution and pressure relief stage of the swash plate axial piston pump according to claim 1 is characterized in that: When the plunger cavity (8) rotates to communicate with the oil supply groove (4), the plunger cavity distribution window (9) completely covers the oil supply groove (4).

3. An energy recovery method using the device according to any one of claims 1 to 2, characterized in that: The high-pressure oil discharged during the pressure relief process of the plunger cavity (8) is sequentially guided to the recovery chamber (6) through the recovery hole group (3), the distribution plate recovery flow channel (2), and the rear end cover recovery flow channel (5); When the plunger cavity (8) enters the oil absorption stage, the high-pressure oil in the recovery chamber flows back to the plunger cavity (8) through the recovery hole group (3) and the oil replenishment groove (4) in sequence to compensate for the pressure, thereby realizing energy recovery and reuse in the flow distribution process.

4. The energy recovery method according to claim 3, characterized in that: The oil replenishing groove (4) prolongs the communication time between the plunger cavity and the recovery chamber (6), thereby increasing the flow rate of oil from the recovery chamber to the plunger cavity.

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