A static pressure balance distribution shaft with an arc-shaped pressure equalization groove

Abstract

This invention belongs to the field of hydraulic component design technology, and relates to the design, process research and manufacturing of a static pressure balance structure for high and low pressure distribution of the distribution shaft in a radial piston pump with axial flow distribution. Specifically, it is a static pressure balance distribution shaft with arc-shaped pressure equalizing grooves. This solves the technical problem of poor static pressure balance in the overall structure of the distribution shaft of current radial piston pumps with axial flow distribution, resulting in unstable pump performance under high pressure and severe wear in the high-pressure area of ​​the distribution shaft. The static pressure balance distribution shaft with arc-shaped pressure equalizing grooves has high and low pressure arc grooves and high and low pressure distribution windows on it. Internally, there are high and low pressure channels connecting the high and low pressure grooves and the corresponding distribution windows. Pressure ports and suction ports are respectively opened on the high and low pressure arc grooves. A pressure equalizing groove is opened on both the left and right sides of the high and low pressure arc grooves. The pressure equalizing grooves are circumferential arc-shaped grooves, which are arranged in a wave-like pattern around the circumference of the distribution shaft, so that the distance t between the edge of the pressure equalizing groove and the edge of the high and low pressure arc groove is controlled within a certain range.

Description

Technical Field

[0001] This invention belongs to the field of hydraulic component design technology, and relates to the design, process research and manufacturing of a static pressure balance structure for high and low pressure distribution of a radial piston pump with a distribution shaft, specifically a static pressure balance distribution shaft with an arc-shaped pressure equalization groove. Background Technology

[0002] Currently, China mainly relies on imports for high-performance, high-end radial piston pumps. Imported pumps suffer from drawbacks such as high prices, long delivery cycles, and difficult maintenance, while there are no domestic alternatives. Given this situation, in-depth research into the design and manufacturing processes of various friction pairs in axial-distribution radial piston pumps is of profound significance for promoting the development of high-end hydraulic components in my country.

[0003] In a radial piston pump with axial distribution, one side of the distribution shaft is a high-pressure chamber, and the other side is a low-pressure chamber. During operation, the distribution shaft is subjected to a large radial unbalanced force, pushing it to one side and increasing the clearance on the other side. This leads to increased wear and leakage on the sliding surfaces of the friction pair, resulting in decreased pump efficiency and even damage to the friction pair surfaces. To solve this problem, certain static pressure balancing measures must be taken. In the field of hydraulic component design, the most common methods are using communication channels, pre-pressurization, and pre-depressurization channels to achieve static pressure balance on the distribution shaft. Therefore, the design of the static pressure balancing structure on the distribution shaft is crucial. It determines whether the pump will suffer severe cavitation, wear, and other damage due to pressure shocks during operation, thus seriously affecting the pump's service life. In other words, the structure and parameter design of the equalizing channels and throttling channels on the distribution shaft must be based on a combination of theoretical calculations and actual experiments. A solid lubricating coating should also be applied to the friction pair to give it excellent self-lubricating and shock-resistant properties. This will greatly improve the axial radial piston pump's long service life, low noise, and shock resistance, which is even more important for pumps operating on high-water-based media.

[0004] In existing technologies, the friction pair between the distribution shaft and the rotor of axial-distribution radial piston pumps is a high-speed, heavy-load friction pair, making full hydrostatic balance design difficult. Therefore, the hydrostatic balance structure design on the distribution shaft is crucial during high-low pressure switching. Currently, the left and right pressure equalizing grooves on the distribution shaft are all circumferential annular grooves. Figure 7 As shown, b is the width of the circumferential groove), and there is one pre-depressurization and one pre-pressurization throttling groove. The overall static pressure balance effect is not good, which causes the pump to be unstable under high pressure. The high-pressure area of ​​the distribution shaft is severely worn, especially with high water-based working media, cavitation damage is very serious, which to a certain extent restricts the development of axial distribution radial piston pump products. Summary of the Invention

[0005] The present application provides a static pressure balance flow distribution shaft with an arc-shaped pressure equalizing groove to solve the technical problem of poor static pressure balance effect of the overall structure of the flow distribution shaft of the current shaft flow distribution radial piston pump, causing unstable performance of the pump under high pressure and serious wear of the high pressure area of the flow distribution shaft.

[0006] The present application is implemented by using the following technical scheme: a static pressure balance flow distribution shaft with an arc-shaped pressure equalizing groove, the flow distribution shaft is provided with high and low pressure arc grooves and high and low pressure flow distribution windows, and high and low pressure channels are formed in the flow distribution shaft to communicate the high and low pressure grooves and the corresponding flow distribution windows; the high and low pressure arc grooves are respectively provided with oil inlet ports and oil suction ports; a pressure equalizing groove is formed on the left and right sides of the high and low pressure arc grooves, the pressure equalizing groove is a circumferential arc-shaped ring groove, and the circumferential arc-shaped ring groove is arranged in a wave shape around the circumference of the flow distribution shaft, so that the distance t between the edge of the pressure equalizing groove and the edge of the high and low pressure arc grooves is controlled within a range.

[0007] The present application designs a novel high and low pressure flow distribution static pressure balance structure of a radial piston pump, the overall structure is that the left and right pressure equalizing grooves on the flow distribution shaft are circumferential arc-shaped ring grooves, and the distance t between the edge of the pressure equalizing groove and the edge of the high and low pressure arc grooves is controlled within a certain range, so that the radial force acting on the flow distribution shaft changes with the change of t, the balance force acting on the arc-shaped ring groove is obviously larger than that acting on a circular groove, and the balance of the radial hydraulic pressure of the flow distribution shaft can be effectively improved.

[0008] Further, a pre-pressure relief large throttle groove connected with the low pressure arc groove and a pre-pressure rising throttle groove connected with the high pressure arc groove are formed in the partition wall region between the high and low pressure arc grooves on the circumference of the flow distribution shaft; the pre-pressure relief large throttle groove and the pre-pressure rising throttle groove are located at positions separated by 180 degrees on the circumference of the flow distribution shaft, and the pre-pressure relief large throttle groove and the pre-pressure rising throttle groove are located on the annular connecting line at the center of the bottom of the high and low pressure arc grooves and have the same trend as the annular connecting line; a pre-pressure relief small throttle groove connected with the low pressure arc groove is further formed in the pre-pressure relief large throttle groove on the circumference of the flow distribution shaft, and the pre-pressure relief small throttle groove has the same trend as the pre-pressure relief large throttle groove.

[0009] The pre-pressure relief groove on the flow distribution shaft is designed as a large and small throttle groove matching structure, and the pre-pressure rising groove is designed as a throttle groove. The wrap angle, side length and depth of the throttle groove are all selected according to different parameters according to different flow rates, so as to eliminate noise, pressure impact and cavitation damage to parts caused by sudden pressure change.

[0010] Further, the size of the partition wall sealing band between the high and low pressure grooves is greater than the diameter of the piston matched with the flow distribution shaft.

[0011] The size of the partition wall sealing band on the flow distribution shaft is slightly larger than the diameter of the piston, which is beneficial to reduce leakage and improve the volumetric efficiency of the pump.

[0012] The scheme improves the balance of the radial hydraulic pressure of the distribution shaft effectively through the circumferential arc-shaped ring groove, and effectively eliminates the noise, pressure impact and cavitation damage to the parts caused by the pressure mutation through the cooperation of the two throttle grooves and the design of the pre-pressure boosting groove. The static pressure balance effect is good, the performance of the pump is stable under high pressure, the wear of the distribution shaft in the high pressure area is effectively reduced, the cavitation damage is reduced, and the development potential of the shaft distribution radial piston pump product is improved. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 Main structure schematic diagram of distribution shaft.

[0014] Figure 2 For Figure 1 A-A sectional view.

[0015] Figure 3 For Figure 1 B-B sectional view.

[0016] Figure 4 For Figure 2 C-C sectional view in.

[0017] Figure 5 Schematic diagram of distribution process of distribution shaft.

[0018] Figure 6 Schematic diagram of distribution process of distribution shaft.

[0019] Figure 7 Pressure distribution diagram of circular pressure equalizing groove of distribution shaft.

[0020] Figure 8 Pressure distribution diagram of arc-shaped pressure equalizing groove of distribution shaft.

[0021] 1. Distribution shaft, 2. Left arc-shaped pressure equalizing groove, 3. Right arc-shaped pressure equalizing groove, 4. Pre-pressure relief large throttle groove, 5. Pre-pressure boosting throttle groove, 6. Pre-pressure relief small throttle groove, 7. Oil suction port, 8. Partition wall sealing band, 9. Oil discharge port, 10. Screwed nut. DETAILED DESCRIPTION Example 1

[0022] A static pressure balanced distribution shaft with arc-shaped pressure equalizing grooves, the distribution shaft 1 is provided with high and low pressure arc grooves and high and low pressure distribution windows, and high and low pressure channels are formed in the inside to communicate the high and low pressure grooves and the corresponding distribution windows; the high and low pressure arc grooves are respectively provided with oil discharge ports 9 and oil suction ports 7; a pressure equalizing groove is formed on the left and right sides of the high and low pressure arc grooves, the pressure equalizing groove adopts a circumferential arc-shaped ring groove, the circumferential arc-shaped ring groove is arranged in a wave shape around the circumference of the distribution shaft, so that the distance t between the edge of the pressure equalizing groove and the edge of the high and low pressure arc grooves is controlled within a range. Example 2

[0023] Figure 1 、 2 , 3, two partition wall regions between high and low pressure arc grooves on the circumference of the flow distribution shaft 1 are respectively provided with a pre-pressure relief large throttle groove 4 connected with the low pressure arc groove and a pre-pressure rising throttle groove 5 connected with the high pressure arc groove; the pre-pressure relief large throttle groove 4 and the pre-pressure rising throttle groove 5 are located at positions 180 degrees apart on the circumference of the flow distribution shaft, and the pre-pressure relief large throttle groove 4 and the pre-pressure rising throttle groove 5 are located on the annular connecting line of the center of the bottom of the high and low pressure arc grooves and have the same trend as the annular connecting line; a pre-pressure relief small throttle groove 6 in communication with the low pressure arc groove is further provided beside the pre-pressure relief large throttle groove 4 on the circumference of the flow distribution shaft 1, and the pre-pressure relief small throttle groove 6 has the same trend as the pre-pressure relief large throttle groove 4. The pre-pressure relief large throttle groove 4, the pre-pressure rising throttle groove 5 and the pre-pressure relief small throttle groove 6 are all triangular grooves. Figure 1 , the pre-pressure relief large throttle groove 4 and the pre-pressure relief small throttle groove 6 are shown by dotted lines, and it can be known from 2 and 3 that the pre-pressure relief large throttle groove 4 and the pre-pressure relief small throttle groove 6 are located on the same side and are in communication with the low pressure region; the pre-pressure rising throttle groove 5 is in communication with the high pressure region. Embodiment 3

[0024] Figure 1 In the embodiment, the distance m between the right edge of the left arc-shaped pressure equalizing groove 2 and the left edge of the high and low pressure arc grooves at the top and bottom positions of the flow distribution shaft and the distance m between the left edge of the right arc-shaped pressure equalizing groove 3 and the right edge of the high and low pressure arc grooves are both 5 mm. t is 3-7 mm, and the width of the pressure equalizing groove is 2.5 mm. Figure 5 In the embodiment, the center distance between the pre-pressure relief large throttle groove 4 and the pre-pressure relief small throttle groove 6 is 2.5 mm; the above-mentioned sizes have the best application effect. Embodiment 4

[0025] The size C of the partition wall sealing band between the high and low pressure grooves is slightly larger than the diameter of the plunger matched with the flow distribution shaft (1.5-2.5 mm larger). Figure 4 As shown, the end parts of the high and low pressure channels are firmly sealed by the screw plugs 10 coated with anaerobic glue, and the sealing effect is good.

[0026] The working principle of the present application is shown in combination with 1-8. Figure 1 , 4 , 6, 8, the low pressure oil is sucked into the pump body through the oil suction port 7, when the rotor rotates to the lower half, the oil is relieved due to the increase of the sealing volume, enters the plunger cavity through the internal channel of the flow distribution shaft, when the rotor rotates to the upper half, the oil is pressurized due to the decrease of the sealing volume, is discharged from the high pressure area of the upper half of the flow distribution shaft through the oil discharge port 9 of the pump. In the above-mentioned high and low pressure conversion process of the pump, when the plunger working cavity is separated from the oil discharge port 9 of the flow distribution shaft with the rotation of the rotor, because the size C of the partition wall sealing band 8 is slightly larger than the diameter D of the plunger, the plunger working cavity is firstly connected with the pre-pressure relief large unloading throttle groove 4, and then is simultaneously connected with the pre-pressure relief large and small throttle grooves 4 and 6, so that the pressure impact of the hydraulic oil during the conversion from high to low is reduced, and the oil passes through the unloading groove area δ1 (δ1 is the distance between the center of the pre-pressure relief large throttle groove 4 and the center of the pre-pressure relief small throttle groove 6) and is discharged from the oil discharge port 9 of the pump. Figure 6), the plunger working cavity pressure Ps drops to the pressure P0 of the suction port 7 of the matching shaft, and the oil suction starts; when the plunger working cavity is separated from the suction port 7 of the matching shaft, because the size C of the partition wall sealing strip 8 is slightly larger than the diameter D of the plunger, the plunger working cavity is connected with the pre-pressurization throttling groove 5, and the pressure impact of the hydraulic oil during the conversion from low to high is reduced, and after passing through the oil groove area δ2, the plunger working cavity pressure P0 drops to the pressure Ps of the pressure oil port 9 of the matching shaft, and the oil pressing starts; the left and right arc-shaped equalizing grooves 2 and 3 can communicate the high and low pressure areas of the matching shaft 1, and the distance t between the edges of the equalizing grooves and the edges of the high and low pressure arc grooves is controlled to be 3-7 mm, so that the radial force borne by the matching shaft changes with t, which is different from the circular equalizing groove, and the balance force borne by the arc-shaped ring groove is obviously larger than that of the circular groove, so that the balance of the radial hydraulic pressure of the matching shaft 1 can be effectively improved, and the serious eccentric wear or jamming of the matching shaft 1 due to the unbalanced radial force can be prevented. Figure 8 A is the width of the high and low pressure arc grooves.

[0027] Technical features of the present application:

[0028] (1) The left and right high and low pressure communication grooves on the matching shaft are all circular arc-shaped ring grooves, and the distance t between the edges of the equalizing grooves and the edges of the high and low pressure arc grooves is controlled to be 3-7 mm, so that the radial force borne by the matching shaft changes with t, and the balance force borne by the arc-shaped ring groove is obviously larger than that of the circular groove, so that the balance of the radial hydraulic pressure of the matching shaft can be effectively improved.

[0029] (2) The pre-pressure relief groove on the matching shaft is designed as a structure with two throttle ports, and the pre-pressurization groove is designed as a throttle port. The wrap angle, edge length and depth of the throttle port are all selected according to different parameters to eliminate noise, pressure impact and cavitation damage to the parts caused by sudden pressure changes.

[0030] (3) The size C of the partition wall sealing strip on the matching shaft is slightly larger than the diameter D of the plunger, which is beneficial to reduce the leakage and improve the volumetric efficiency of the pump.

[0031] (4) The high and low pressure channels on the matching shaft are all sealed by the anaerobic glue coated on the screw.

Claims

1. A static pressure balance flow distribution shaft with arc-shaped pressure equalizing grooves, the flow distribution shaft (1) is provided with high and low pressure arc grooves and high and low pressure flow distribution windows, and high and low pressure channels are formed in the flow distribution shaft (1) to communicate the high and low pressure grooves and the corresponding flow distribution windows; the high and low pressure arc grooves are respectively provided with oil inlet ports (9) and oil suction ports (7); characterized in that, Both sides of the high and low pressure arc groove are opened with an equalizing groove, the equalizing groove adopts a circumferential arc ring groove, the circumferential arc ring groove is arranged in a wave shape around the circumference of the flow distribution shaft (1), so that the distance t between the edge of the equalizing groove and the edge of the high and low pressure arc groove is controlled within 3-7mm; The size of the partition wall sealing strip (8) between the high and low pressure grooves is greater than the diameter of the plunger matched with the flow distribution shaft (1).

2. A hydrostatically balanced flow distribution shaft with arc-shaped pressure equalizing grooves as claimed in claim 1, characterized in that A pre-pressure relief large throttle groove (4) connected with the low pressure arc groove and a pre-pressure rising throttle groove (5) connected with the high pressure arc groove are opened in the partition wall area on the circumference of the flow distribution shaft (1) between the high and low pressure arc grooves; the pre-pressure relief large throttle groove (4) and the pre-pressure rising throttle groove (5) are located at positions 180 degrees apart on the circumference of the flow distribution shaft (1), and the pre-pressure relief large throttle groove (4) and the pre-pressure rising throttle groove (5) are located on the annular connecting line at the center of the bottom of the high and low pressure arc grooves and have the same trend as the annular connecting line; a pre-pressure relief small throttle groove (6) in communication with the low pressure arc groove is also opened beside the pre-pressure relief large throttle groove (4) on the circumference of the flow distribution shaft (1), and the pre-pressure relief small throttle groove (6) has the same trend as the pre-pressure relief large throttle groove (4).

3. A hydrostatically balanced flow-strut with arc-shaped pressure equalizing slots as claimed in claim 2, characterized in that, The pre-pressure relief large throttle groove (4), the pre-pressure rising throttle groove (5) and the pre-pressure relief small throttle groove (6) are all triangular grooves.

4. A hydrostatically balanced flow-strutted shaft with arc-shaped fairing grooves as claimed in any one of claims 1 to 3, characterized in that, The width of the equalizing groove is 2.5mm; the center distance between the pre-pressure relief large throttle groove (4) and the pre-pressure relief small throttle groove (6) is 2.5mm.

5. A hydrostatically balanced flow-strut with arc-shaped pressure equalizing slots as claimed in any one of claims 1 to 3, characterized in that The end of the high and low pressure channel is firmly sealed with a screw plug (10) coated with anaerobic adhesive.

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