Plunger pump rear cover of vortex type oil duct structure

Abstract

The utility model discloses a plunger pump rear cover with a vortex type oil duct structure, which is provided with a central axis, an oil suction channel and an oil outlet channel are distributed along the first radial direction of the central axis, the central axis is positioned between the oil suction channel and the oil outlet channel, and the outer end of the rear cover is provided with an oil suction port and an oil outlet which are connected with one ends of the two channels. The oil suction channel comprises a first channel section and a second channel section, the first channel section is connected with the oil suction port, the large end of the second channel section is connected with the first channel section, and the small end of the second channel section is connected with the oil suction crescent groove. The distance between the hole center of the small end of the second channel section and the central axis of the rear cover is smaller than the distance between the hole center of the large end of the second channel section and the central axis of the rear cover, and the hole diameter of the small end of the second channel section is the same as the radial width of the oil absorption crescent groove. The structure solves the problems that an existing rear cover is prone to turbulent flow, cavities, pressure loss and overlarge in size, and the high rotating speed and compact type requirements of the plunger pump are met.

Description

Technical Field

[0001] The utility model relates to a plunger pump rear cover with a vortex oil channel structure. Background Art

[0002] The swash plate axial piston pump is the heart of the hydraulic system and is a device that converts mechanical energy into hydraulic energy. It is widely used in engineering machinery, agricultural machinery, mining machinery, industrial equipment and other fields because of its high power-to-weight ratio, stepless flow adjustment, high continuous pressure, excellent oil absorption performance, high allowable speed, high reliability, long life, high efficiency and energy saving, good sealing, low noise level and low flow pulsation. Some machines are very compact in size, and the installation space reserved for the pump they carry is very narrow, which puts forward requirements for the plunger pumps they carry at higher speeds and smaller sizes.

[0003] The basic structure of a swash plate axial piston pump is mainly composed of a rotating shaft, a cylinder body, a plunger, a swash plate, a distribution plate, a pump body, a rear cover, etc. The rotating shaft and the cylinder body are usually connected by a spline. When the rotating shaft drives the cylinder body to rotate, the plungers evenly distributed along the circumference of the cylinder body rotate with the cylinder body. At the same time, the plunger head is acted upon by the inclined surface of the swash plate to make reciprocating motion in the cylinder body hole. The rotating shaft is supported by bearings to keep the axis stable. The cylinder body distribution surface fits the distribution plate, and oil suction and discharge are achieved through the oil suction and oil pressure windows on the distribution plate. The inclination angle of the swash plate can be adjusted to change the plunger stroke and thus adjust the displacement of the pump. The splines of the rotating shaft and the cylinder body cooperate to transmit torque, so that the cylinder body rotates synchronously with the shaft, driving the plunger to complete the oil suction and discharge process.

[0004] The rear cover serves as the rear end closing component of the pump body and is tightly connected to the pump body to form a closed hydraulic chamber. Its inner side cooperates with the distribution plate, and is connected to the oil suction and oil pressure windows of the distribution plate through the processed oil suction crescent groove and oil discharge crescent groove, forming a key channel for oil suction and discharge.

[0005] In the existing technology, the rear cover oil suction channel structure of the swash plate axial piston pump is simple, and turbulence and cavitation are easily generated when the oil flows, resulting in a large oil suction pressure loss and insufficient oil suction capacity, making it difficult to adapt to high-speed working conditions; at the same time, in order to ensure strength, the traditional rear cover has not been optimized in structure and has a large volume, which cannot meet the equipment's demand for a compact pump body and is difficult to adapt to the requirements of engineering machinery and other fields for miniaturization and high-speed use of the pump body. Utility Model Content

[0006] In response to the above-mentioned deficiencies in the existing technology, the utility model provides a plunger pump back cover with a vortex oil channel structure, which solves the problems of turbulence, cavitation, pressure loss and excessive volume caused by the unreasonable design of the oil suction channel of the existing plunger pump back cover, and is adapted to the high speed and compact requirements of the plunger pump.

[0007] The rear cover of the plunger pump of the vortex oil passage structure of the present invention has a central axis, and the central axis corresponds to the inner and outer end directions of the rear cover. The rear cover is provided with an oil suction channel and an oil outlet channel distributed along the first radial direction of the central axis. The central axis of the rear cover is located between the oil suction channel and the oil outlet channel in the first radial direction. The outer end of the rear cover along the central axis is provided with an oil suction port and an oil outlet port respectively connected to one end of the oil suction channel and the oil outlet channel. The inner end of the rear cover along the central axis is provided with an oil suction crescent groove and an oil outlet crescent groove respectively connected to the other end of the oil suction channel and the oil outlet channel. The arc center is located on the central axis of the rear cover, and the oil suction channel includes a first channel section and a second channel section that are connected to each other. The first channel section is cylindrical and connected to the oil suction port. The second channel section is trumpet-shaped and has a large end with a relatively large aperture and a small end with a relatively small aperture. The large end of the second channel section is connected to the first channel section, and the small end of the second channel section is connected to the oil suction crescent groove. The distance between the hole center of the small end of the second channel section and the central axis of the rear cover is smaller than the distance between the hole center of the large end of the second channel section and the central axis of the rear cover. The aperture of the small end of the second channel section is the same as the radial width of the oil suction crescent groove.

[0008] The oil channel structure layout of the rear cover of the plunger pump of the present invention is relatively compact. Through the connection structure design of the cylindrical first channel section and the trumpet-shaped second channel section of the oil suction channel, the oil enters from the oil suction port through the first channel section and smoothly transitions to the oil suction crescent groove through the trumpet-shaped second channel section, thereby reducing the turbulence and cavitation of the oil flow, reducing the oil suction pressure loss, meeting the high speed requirements of the plunger pump, and optimizing the volume of the rear cover while ensuring performance.

[0009] Furthermore, the inner diameter of the oil suction crescent groove is A and the outer diameter is B, the inner diameter A refers to the distance between the inner side wall of the oil suction crescent groove and the central axis, the outer diameter B refers to the distance between the outer side wall of the oil suction crescent groove and the central axis, the diameter of the first channel section is C, C=2(BA), that is, the diameter of the first channel section is twice the radial spacing between the inner and outer side walls of the oil suction crescent groove, and from the cross-sectional shape along the first radial direction, the length of the straight line profile of the side of the first channel section away from the central axis of the rear cover is a, and the length of the straight line profile of the side of the first channel section close to the central axis of the rear cover is b, b>a, which can optimize the oil flow path, reduce turbulence and pressure loss, while taking into account the compactness of the structure, and adapt to the high speed requirements of the plunger pump.

[0010] Furthermore, from the cross-sectional shape along the first radial direction, the side of the second channel section away from the central axis of the rear cover has a first oblique profile, a first arc profile smoothly connected to the side wall of the corresponding side of the first channel section, and a second arc profile smoothly connected to the side wall of the corresponding side of the oil suction crescent groove; the side of the second channel section close to the central axis of the rear cover has a second oblique profile, a third arc profile smoothly connected to the side wall of the corresponding side of the first channel section, and a fourth arc profile smoothly connected to the side wall of the corresponding side of the oil suction crescent groove; the inclination of the first oblique profile relative to the central axis is greater than that of the second oblique profile.

[0011] Based on the above scheme, when the oil flows from the oil suction port to the oil suction crescent groove, the flow direction changes gradually and smoothly, avoiding sudden turns during the flow of the oil and reducing the occurrence of turbulence; the smooth oblique line and arc transition structure reduces the flow resistance of the oil in the channel, reduces the pressure loss during the oil suction process, helps to improve the oil suction efficiency of the plunger pump, and enables the oil to maintain a stable flow state at high speed, reduces the occurrence of cavitation, and ensures the operation of the plunger pump under high speed conditions. In addition, the above channel structure design can reduce the occupation of the internal space of the rear cover, and the structure is more compact.

[0012] Furthermore, the inclination angle of the first oblique profile relative to the central axis is γ, and the inclination angle of the second oblique profile relative to the central axis is β, γ=2β. This design can guide the oil to smoothly turn from the first channel section to the oil suction crescent groove, reducing turbulence and pressure loss caused by sudden path changes.

[0013] Furthermore, the first, second, third and fourth arc profiles are all arc-shaped, the radius of the first arc profile is R1, the radius of the second arc profile is R2, the radius of the third arc profile is R3, and the radius of the fourth arc profile is R4, R3=0.8R1, R2=0.4R1, R4=0.2R1. By connecting arcs of different radii, the corners and mutations in the oil flow process are reduced, the generation of turbulence and cavitation is further reduced, the oil suction pressure loss is reduced, and the high-speed operation requirements of the plunger pump are adapted. This standardized radius ratio design is more conducive to CNC machining.

[0014] Furthermore, two bearing flushing oil circuits are distributed along the second radial direction of the central axis of the rear cover. The central axis of the rear cover is located between the two bearing flushing oil circuits in the second radial direction. The first radial direction and the second radial direction are perpendicular to each other. The two bearing flushing oil circuits are located between the oil suction channel and the oil outlet channel in the first radial direction, which rationally utilizes the internal space of the rear cover to make the rear cover structure more compact.

[0015] The beneficial effects of the present invention are as follows: the oil channel structure of the rear cover of the plunger pump of the present invention has a compact layout, which can reduce the volume of the rear cover; the oil suction channel adopts a cylindrical first channel section connected with a trumpet-shaped second channel section, so that the oil flows smoothly from the oil suction port through the first channel section and the second channel section into the oil suction crescent groove, reducing turbulence and cavitation, reducing pressure loss, adapting to the high speed requirements of the plunger pump, and having advantages in performance and compact structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The structure of the embodiment of the utility model Figure 1 ;

[0017] Figure 2 The structure of the embodiment of the utility model Figure 2 ;

[0018] Figure 3 This is a schematic diagram of the axial outer end of an embodiment of the present utility model;

[0019] Figure 4 This is a schematic diagram of the axial inner end of an embodiment of the present utility model;

[0020] Figure 5 for Figure 4 Sectional view along section line XX;

[0021] Figure 6 This is a radial cross-sectional view corresponding to the large end of the second channel section of the embodiment of the utility model;

[0022] Figure 7 This is a radial cross-sectional view corresponding to the small end of the second channel section of the embodiment of the utility model;

[0023] Figure 8 A performance comparison test chart of the utility model and existing products;

[0024] Figure 9 This is a performance test table for plunger pumps with the rear cover of the utility model and a conventional rear cover. DETAILED DESCRIPTION

[0025] The implementation of the plunger pump rear cover of the vortex oil channel structure of the utility model is as follows: Figure 1-9As shown, the rear cover has a central axis 10, and the central axis 10 corresponds to the inner and outer end directions of the rear cover. The rear cover is distributed with an oil suction channel 2 and an oil outlet channel 3 along the first radial direction of the central axis 10. The central axis 10 of the rear cover is located between the oil suction channel 2 and the oil outlet channel 3 in the first radial direction. The outer end of the rear cover along the central axis 10 is correspondingly provided with an oil suction port 11 and an oil outlet port 12 connected to one end of the oil suction channel 2 and the oil outlet channel 3 respectively. The inner end of the rear cover along the central axis 10 is correspondingly provided with an oil suction crescent groove 13 and an oil outlet crescent groove 14 connected to the other end of the oil suction channel 2 and the oil outlet channel 3 respectively. The arc centers of the oil suction crescent groove 13 and the oil outlet crescent groove 14 are located on the central axis of the rear cover. 10, the oil suction channel 2 includes a first channel section 21 and a second channel section 22 that are connected to each other. The first channel section 21 is cylindrical and connected to the oil suction port 11. The second channel section 22 is trumpet-shaped and has a large end with a relatively large aperture and a small end with a relatively small aperture. The large end of the second channel section 22 is connected to the first channel section 21, and the small end of the second channel section 22 is connected to the oil suction crescent groove 13. The distance between the hole center of the small end of the second channel section 22 and the central axis 10 of the rear cover is smaller than the distance between the hole center of the large end of the second channel section 22 and the central axis 10 of the rear cover. The aperture of the small end of the second channel section 22 is the same as the radial width of the oil suction crescent groove 13.

[0026] The oil channel structure layout of the rear cover of the plunger pump of the present invention is relatively compact. Through the connection structure design of the cylindrical first channel section 21 and the trumpet-shaped second channel section 22 of the oil suction channel 2, the oil enters from the oil suction port 11 through the first channel section 21 and smoothly transitions to the oil suction crescent groove 13 through the trumpet-shaped second channel section 22, reducing the turbulence and cavitation of the oil flow, reducing the oil suction pressure loss, meeting the high speed requirements of the plunger pump, and optimizing the volume of the rear cover while ensuring performance.

[0027] The inner diameter of the oil suction crescent groove 13 is A, and the outer diameter is B. The inner diameter A refers to the distance between the inner side wall of the oil suction crescent groove 13 and the central axis 10, and the outer diameter B refers to the distance between the outer side wall of the oil suction crescent groove 13 and the central axis 10. The diameter of the first channel section 21 is C, C=2(BA), that is, the diameter of the first channel section 21 is twice the radial distance between the inner and outer side walls of the oil suction crescent groove 13, and from the first radial direction (i.e. Figure 4 From the cross-sectional shape (in the direction of the XX section line), the length of the linear wheel on the side of the first channel section 21 away from the central axis 10 of the rear cover is a, and the length of the straight contour on the side of the first channel section 21 close to the central axis 10 of the rear cover is b, which is slightly larger than a. This can optimize the oil flow path, reduce turbulence and pressure loss, and take into account the compactness of the structure to adapt to the high speed requirements of the plunger pump.

[0028] like Figure 5 As shown, from the cross-sectional shape along the first radial direction, the side of the second channel section 22 away from the central axis 10 of the rear cover has a first oblique profile 22a, a first arc profile 22b smoothly transitioned to the side wall of the corresponding side of the first channel section 21, and a second arc profile 22c smoothly transitioned to the side wall of the corresponding side of the oil suction crescent groove 13; the side of the second channel section 22 close to the central axis 10 of the rear cover has a second oblique profile 22d, a third arc profile 22e smoothly transitioned to the side wall of the corresponding side of the first channel section 21, and a fourth arc profile 22f smoothly transitioned to the side wall of the corresponding side of the oil suction crescent groove 13; the inclination of the first oblique profile 22a relative to the central axis 10 is greater than that of the second oblique profile 22d.

[0029] Based on the above scheme, when the oil flows from the oil suction port 11 to the oil suction crescent groove 13, the flow direction changes gradually and smoothly, avoiding sudden turns during the flow of the oil and reducing the occurrence of turbulence; the smooth oblique line and arc transition structure reduces the flow resistance of the oil in the channel, reduces the pressure loss during the oil suction process, helps to improve the oil suction efficiency of the plunger pump, and enables the oil to maintain a stable flow state at high speed, reduces the occurrence of cavitation, and ensures the operation of the plunger pump under high speed conditions. In addition, the above-mentioned channel structure design can reduce the occupation of the internal space of the rear cover, and the structure is more compact.

[0030] The inclination angle of the first oblique profile 22a relative to the central axis 10 is γ, and the inclination angle of the second oblique profile 22d relative to the central axis 10 is β, γ=2β. This design can guide the oil to smoothly turn from the first channel section 21 to the oil suction crescent groove 13, reducing turbulence and pressure loss caused by sudden path changes.

[0031] The first, second, third and fourth arc profiles are all arc-shaped, the radius of the first arc profile 22b is R1, the radius of the second arc profile 22c is R2, the radius of the third arc profile 22e is R3, and the radius of the fourth arc profile 22f is R4, R3=0.8R1, R2=0.4R1, R4=0.2R1. By connecting arcs of different radii, the corners and mutations in the oil flow process are reduced, the generation of turbulence and cavitation is further reduced, the oil suction pressure loss is reduced, and the high-speed operation requirements of the plunger pump are adapted. In addition, this standardized radius ratio design is more conducive to CNC machining.

[0032] The overall structure of the oil suction channel 2 of the rear cover of the present invention, especially the second channel section 22, presents a continuous and smooth transition along the circumferential direction. The profile on the side away from the central axis 10 (including the first oblique profile 22a, the first arc profile 22b, and the second arc profile 22c) and the profile on the side close to the central axis 10 (including the second oblique profile 22d, the third arc profile 22e, and the fourth arc profile 22f) observed from the cross-section along the first radial direction are not two isolated side walls, but two opposite key parts of the complete circumferential profile of the oil suction channel 2. These two side profiles are connected to each other by a circumferential arc transition structure (for example, by Figure 6 、 Figure 7 The arc profile 22g shown in the figure is smoothly connected), forming a closed and smooth annular channel with no obvious corners or sudden changes in the circumferential direction, ensuring that when the oil flows in the channel, it can maintain a continuous and stable flow direction no matter where along the circumference, further reducing turbulence and pressure loss. Figure 6 and Figure 7 As shown, the radial cross-sectional profile of the second channel section 22 gradually changes from a circular profile to a crescent profile from the large end to the small end, and its aperture also gradually becomes smaller, and its two ends are smoothly connected to the oil suction port 11 and the oil suction crescent groove 13 respectively.

[0033] In addition, if Figure 4 As shown, the rear cover is provided with two bearing flushing oil circuits 4 distributed along the second radial direction of the central axis 10. The central axis 10 of the rear cover is located between the two bearing flushing oil circuits 4 in the second radial direction. The first radial direction and the second radial direction are perpendicular to each other. The two bearing flushing oil circuits 4 are located between the oil suction channel 2 and the oil outlet channel 3 in the first radial direction, which rationally utilizes the internal space of the rear cover to make the rear cover structure more compact.

[0034] The performance test comparison of the plunger pump with the rear cover of the utility model and the conventional rear cover is as follows Figure 9 As shown, the experimental data show that the vortex oil channel structure of the utility model can effectively enhance the anti-cavitation ability of the plunger pump, reduce turbulence and cavitation during the flow of oil, and reduce the oil suction pressure loss, so that it can still maintain stable oil suction performance under high-speed conditions, better adapt to the high-speed requirements of the plunger pump, and at the same time have advantages in structural compactness, solving the problem of the large rear cover volume in the prior art.

[0035] The above embodiment is only one preferred embodiment of the present invention. Common changes and substitutions made by those skilled in the art within the scope of the technical solution of the present invention are all included in the protection scope of the present invention.

Claims

1. A rear cover of a plunger pump with a vortex oil passage structure, the rear cover having a central axis, an oil suction channel and an oil outlet channel distributed along the first radial direction of the central axis, the central axis of the rear cover being located between the oil suction channel and the oil outlet channel in the first radial direction, an oil suction port and an oil outlet port correspondingly connected to one end of the oil suction channel and the oil outlet channel, respectively, at the outer end of the rear cover along the central axis, an oil suction crescent groove and an oil outlet crescent groove correspondingly connected to the other end of the oil suction channel and the oil outlet channel, respectively, at the inner end of the rear cover along the central axis, the arc centers of the oil suction crescent groove and the oil outlet crescent groove being located on the central axis of the rear cover, characterized in that: The oil suction channel includes a first channel section and a second channel section that are connected to each other. The first channel section is cylindrical and connected to the oil suction port. The second channel section is trumpet-shaped and has a large end with a relatively large aperture and a small end with a relatively small aperture. The large end of the second channel section is connected to the first channel section, and the small end of the second channel section is connected to the oil suction crescent groove. The distance between the hole center of the small end of the second channel section and the central axis of the rear cover is smaller than the distance between the hole center of the large end of the second channel section and the central axis of the rear cover. The aperture of the small end of the second channel section is the same as the radial width of the oil suction crescent groove.

2. The rear cover of the plunger pump with a vortex oil passage structure according to claim 1, characterized in that: The inner diameter of the oil suction crescent groove is A, the outer diameter is B, the diameter of the first channel section is C, C=2(BA), and from the cross-sectional shape along the first radial direction, the length of the straight line profile of the first channel section away from the central axis of the rear cover is a, and the length of the straight line profile of the first channel section close to the central axis of the rear cover is b, b>a.

3. The rear cover of the plunger pump with a vortex oil passage structure according to claim 1, characterized in that: From the perspective of the cross-sectional shape along the first radial direction, the side of the second channel section away from the central axis of the rear cover has a first oblique profile, a first arc profile smoothly connected to the side wall of the corresponding side of the first channel section, and a second arc profile smoothly connected to the side wall of the corresponding side of the oil suction crescent groove. The side of the second channel section close to the central axis of the rear cover has a second oblique profile, a third arc profile smoothly connected to the side wall of the corresponding side of the first channel section, and a fourth arc profile smoothly connected to the side wall of the corresponding side of the oil suction crescent groove. The inclination of the first oblique profile relative to the central axis is greater than that of the second oblique profile.

4. The rear cover of the plunger pump with a vortex oil passage structure according to claim 3, characterized in that: The inclination angle of the first oblique line profile relative to the central axis is γ, the inclination angle of the second oblique line profile relative to the central axis is β, and γ=2β.

5. The rear cover of the plunger pump with a vortex oil passage structure according to claim 4, characterized in that: The first, second, third and fourth arc profiles are all arc-shaped, the radius of the first arc profile is R1, the radius of the second arc profile is R2, the radius of the third arc profile is R3, and the radius of the fourth arc profile is R4, R3=0.8R1, R2=0.4R1, R4=0.2R1.

6. The rear cover of the plunger pump with a vortex oil passage structure according to claim 1, characterized in that: Two bearing flushing oil circuits are distributed along the second radial direction of the central axis of the rear cover. The central axis of the rear cover is located between the two bearing flushing oil circuits in the second radial direction. The first radial direction and the second radial direction are perpendicular to each other. The two bearing flushing oil circuits are located between the oil suction channel and the oil outlet channel in the first radial direction.

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