Swash plate for high-speed high-pressure miniature axial plunger pump

Abstract

The invention discloses a swash plate for a high-speed high-pressure small-miniature axial plunger pump, which comprises a plate body (2), an eccentric center hole which is deviated to the bottom dead center of a sliding shoe (4) and deviated to the distance e is arranged in the plate body (2), and an O-shaped orientation groove (14) corresponding to an orientation pin (3) is arranged on the upper side of the plate body (2). The characteristics of large power weight ratio and compact structure of the high-speed high-pressure small and miniature axial plunger pump are realized, the reliability of the high-speed high-pressure small and miniature axial plunger pump is improved, and the swash plate is reliable in positioning and convenient to assemble.

Description

Technical Field

[0001] The invention relates to a swash plate for a plunger pump, in particular to a swash plate for a high-speed and high-pressure small and micro axial plunger pump. Background Art

[0002] As a power element of the hydraulic system, the axial piston pump has the advantages of a large power-to-weight ratio, compact structure, and high volumetric efficiency. In the application fields of aerospace and robotics, due to the limitations of installation space and weight, the axial piston pump is developing towards high speed, high pressure, miniaturization, and higher power-to-weight ratio. How to achieve high-speed and high-pressure performance while reducing the structural size and weight requires a reasonable design of the structural dimensions of the tiny parts in the small and micro axial piston pump, especially the design of the swash plate. The working inclined surface of the swash plate and the large end surface of the sliding shoe are friction pairs. Since the movement trajectory of the sliding shoe on the working inclined surface of the swash plate is The upper and lower dead points of an ellipse are the endpoints of the long axis. The long axis of the elliptical motion trajectory of the sliding shoe is biased toward the lower dead point. When the sliding shoe moves to the upper dead point along the elliptical motion trajectory, the inner edge of the large outer circle of the sliding shoe will exceed the inner circle of the working inclined surface of the inclined plate and enter the hole in the inclined plate, thereby causing the working inclined surface of the inclined plate to be unable to complete the support of the large end face of the sliding shoe, resulting in uneven wear of the large end face of the sliding shoe. To solve this problem, the existing method is to increase the outer diameter of the outer circle of the inclined plate or reduce the diameter of the hole in the inclined plate. The former will increase the size and weight of the inclined plate, and then increase the size and weight of the casing and the entire pump; the latter will cause the hole in the inclined plate to interfere with the return plate. On the other hand, the existing directional hole is a circular hole, which is easy to cause over-positioning and increase the difficulty of assembly. Therefore, the existing technology has the problem of increasing the size and weight of the inclined plate and the entire pump structure, causing interference between parts and difficulty in over-positioning assembly. Summary of the invention

[0003] The purpose of the present invention is to provide a swash plate for a high-speed, high-pressure, small and micro axial piston pump, which not only realizes the characteristics of a high-speed, high-pressure, small and micro axial piston pump with a large power-to-weight ratio and a compact structure, but also improves the reliability of the high-speed, high-pressure, small and micro axial piston pump, and the swash plate is reliably positioned and easy to assemble.

[0004] The technical solution of the present invention is as follows: a swash plate for a high-speed, high-pressure, small and micro axial piston pump comprises a plate body, wherein the plate body is provided with an eccentric center hole which is biased toward the bottom dead point of the sliding shoe and is biased toward a distance e, and an O-shaped orientation groove corresponding to the orientation pin is provided on the upper side of the plate body.

[0005] In the aforementioned swash plate for high-speed and high-pressure micro axial piston pump, the e satisfies the following conditions:

[0006] b=2R / cosγ

[0007]

[0008]

[0009]

[0010]

[0011] L1≤L2,L3≤L4

[0012] Among them, one end of the disk body is a working inclined surface that cooperates with the sliding shoe, and the other end of the disk body is a positioning surface perpendicular to the main axis. The angle between the working inclined surface and the positioning surface is γ, the motion trajectory of the center of the sliding shoe on the working inclined surface is an ellipse, and the upper end point and lower end point of the sliding shoe center on the working inclined surface are the upper dead center and the lower dead center respectively. The straight-line distance from the upper dead center to the lower dead center is b, and the projection distance between the upper dead center and the lower dead center on the vertical plane is 2R. The axis of the eccentric center hole of the disk body projected on the center plane of the O-shaped directional groove to the working inclined surface is divided into an upper semi-axis L1 and a lower semi-axis L3. The intersection of the upper semi-axis L1 and the lower semi-axis L3 is O1, and the distance from point O1 on the working inclined surface of the disk body to the inner edge of the large outer circle of the sliding shoe at the upper dead center is L2, and the distance from point O1 on the working inclined surface of the disk body to the inner edge of the large outer circle of the sliding shoe at the lower dead center is L4.

[0013] In the aforementioned swash plate for high-speed, high-pressure, small and micro axial piston pumps, the O-shaped directional groove includes two groups of semicircular surfaces arranged on the radius of the positioning surface of the plate body and with openings arranged opposite to each other. The radius of the semicircular surface corresponds to the radius of the positioning pin, and a plane tangent to the two semicircular surfaces is provided between the two semicircular surfaces.

[0014] Compared with the prior art, the present invention has the following advantages:

[0015] The disc body of the present application solves the technical problem of increased size and weight of the inclined plate and the entire pump structure, the technical problem of interference between the inclined plate center hole and the return plate, and the technical problem of difficulty in assembly due to over-positioning by setting an O-shaped directional groove. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the structure of the present invention;

[0017] Figure 2 It is a partial enlarged view of the present invention;

[0018] Figure 3 It is a schematic diagram of the structure of the present invention;

[0019] Figure 4 It is a structural schematic diagram of the present invention.

[0020] The markings in the accompanying drawings are: 1-housing, 2-disc, 3-locating pin, 4-slipper, 5-plunger, 6-cylinder body, 7-plunger cavity, 10-locating surface, 13-working inclined surface, 14-0-shaped directional groove, 23-spindle. DETAILED DESCRIPTION

[0021] The present invention is further described below in conjunction with the accompanying drawings and embodiments, but they are not intended to limit the present invention.

[0022] Embodiment. A swash plate for a high-speed, high-pressure, small and micro axial piston pump is constructed as follows Figure 1-4 As shown, it includes a shell 1, a main shaft 23 is provided in the shell 1, a cylinder body 6 is provided on the main shaft 23, a plunger cavity 7 for installing a plunger 5 is provided in the cylinder body 6, a sliding shoe 4 is provided at one end of the plunger 5, a disc body 2 is provided in the shell 1 through a locating pin 3 to cooperate with the sliding shoe 4, an eccentric center hole biased toward the lower dead point of the sliding shoe 4 and biased at a distance e is provided in the disc body 2, and an O-shaped directional groove 14 corresponding to the directional pin 3 is provided on the upper side of the disc body 2.

[0023] The e meets the following conditions:

[0024] b=2R / cosγ

[0025]

[0026]

[0027]

[0028]

[0029] L1≤L2,L3≤L4

[0030] Among them, one end of the disk body 2 is a working inclined surface 13 that cooperates with the sliding shoe 4, and the other end of the disk body 2 is a positioning surface 10 that is perpendicular to the main shaft 23. The angle between the working inclined surface 13 and the positioning surface 10 is γ, and the motion trajectory of the center of the sliding shoe 4 on the working inclined surface 13 is an ellipse. The upper end point and the lower end point of the center of the sliding shoe 4 on the working inclined surface 13 are the upper dead center and the lower dead center respectively. The straight-line distance from the upper dead center to the lower dead center is b, and the projection distance between the upper dead center and the lower dead center on the vertical plane is 2R. The axis of the eccentric center hole of the disk body 2 projected on the center plane of the O-shaped directional groove 14 to the working inclined surface is divided into an upper semi-axis L1 and a lower semi-axis L3. The intersection of the upper semi-axis L1 and the lower semi-axis L3 is O1, and the distance from point O1 on the working inclined surface 13 of the disk body 2 to the inner edge of the large outer circle of the sliding shoe at the upper dead center is L2, and the distance from point O1 on the working inclined surface 13 of the disk body 2 to the inner edge of the large outer circle of the sliding shoe at the lower dead center is L4.

[0031] The O-shaped orientation groove 14 includes two sets of semicircular surfaces arranged on the radius of the positioning surface 10 of the disk body 2 and with openings arranged opposite to each other. The radius of the semicircular surface corresponds to the radius of the positioning pin 3, and a plane tangent to the two semicircular surfaces is arranged between the two semicircular surfaces.

[0032] Principle of the present invention: This application is an improvement on the existing swash plate. The disc body 2 of this application is provided with an eccentric hole which is biased toward the lower dead point of the sliding shoe 4 and has a bias distance e. The calculation of the bias distance e of the eccentric hole needs to be realized based on the cooperation between the existing disc body 2 and the sliding shoe 4. First, the angle γ between the working inclined surface 13 and the positioning surface 10 is determined. The trajectory of the center of the sliding shoe 4 on the working inclined surface 13 is an ellipse 21. The upper end point and the lower end point of the movement of the center of the sliding shoe 4 on the working inclined surface 13 are the upper dead point and the lower dead point respectively. According to the straight line distance b from the upper dead point to the lower dead point and the projection distance 2R of the upper dead point and the lower dead point on the vertical plane, the angle of the swash plate can be obtained. Then, the eccentric distance e is determined by multi-point calculation of L1, L2, L3, and L4, which not only solves the technical problem that causes the increase of the size and weight of the swash plate and the entire pump structure, but also solves the technical problem that causes the interference between the hole in the swash plate and the return plate.

[0033] The O-shaped directional groove is formed by connecting two semicircular surfaces and two planes tangent to the semicircular surfaces. The O-shaped directional groove cooperates with the directional pin. The O-shaped directional groove is oriented in the width t direction. The O-shaped directional groove does not contact the directional pin in the length C direction. The length C of the O-shaped directional groove is greater than the diameter of the directional pin. The width t of the O-shaped directional groove is slightly greater than the diameter of the directional pin, so that the O-shaped directional groove and the directional pin in the width t direction are a clearance fit, but the directional pin can be guided and limited.

Claims

1. A swash plate for a high-speed, high-pressure, small and micro axial piston pump, characterized by: The invention comprises a disc body (2), wherein the disc body (2) is provided with an eccentric center hole which is biased toward the lower dead point of the sliding shoe (4) and is biased toward a distance e, and an O-shaped orientation groove (14) corresponding to the orientation pin (3) is provided on the upper side of the disc body (2).

2. The swash plate for a high-speed and high-pressure small and micro axial piston pump according to claim 1 is characterized in that: The e meets the following conditions: b=2R / cosγ L1≤L2,L3≤L4 One end of the disc body (2) is a working inclined surface (13) matched with the sliding shoe (4), and the other end of the disc body (2) is a positioning surface (10) perpendicular to the main shaft (23). The angle between the working inclined surface (13) and the positioning surface (10) is γ. The movement trajectory of the center of the sliding shoe (4) on the working inclined surface (13) is an ellipse. The upper end point and the lower end point of the movement of the center of the sliding shoe (4) on the working inclined surface (13) are respectively the upper dead point and the lower dead point. The straight line distance from the upper dead point to the lower dead point is b. The distance between the upper dead point and the lower dead point is The projection distance of the dead point on the vertical plane is 2R, the axis of the eccentric hole of the disk body (2) projected on the center plane of the O-shaped directional groove (14) to the working inclined surface is divided into an upper semi-axis L1 and a lower semi-axis L3, the intersection of the upper semi-axis L1 and the lower semi-axis L3 is O1, the distance from point O1 on the working inclined surface (13) of the disk body (2) to the inner edge of the large outer circle of the sliding shoe at the upper dead point is L2, and the distance from point O1 on the working inclined surface (13) of the disk body (2) to the inner edge of the large outer circle of the sliding shoe at the lower dead point is L4.

3. The swash plate for a high-speed and high-pressure small and micro axial piston pump according to claim 1 is characterized in that: The O-shaped orientation groove (14) comprises two groups of semicircular surfaces arranged on the radius of the positioning surface (10) of the disk body (2) and with openings arranged opposite to each other. The radius of the semicircular surface corresponds to the radius of the positioning pin (3), and a plane tangent to the two semicircular surfaces is arranged between the two semicircular surfaces.

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