Duplex axial plunger pump cylinder body capable of resisting cylinder body overturning

Abstract

The utility model relates to the technical field of axial plunger pumps, in particular to a duplex axial plunger pump cylinder body capable of resisting cylinder body overturning, a plurality of spring connecting holes are formed in the periphery of a central shaft cavity at the outer end of the cylinder body in the circumferential direction, and a plurality of cylinder holes are formed in the position, close to the outer edge, of the outer end of the cylinder body in the circumferential direction. A flow distribution surface of a spherical concave surface structure is arranged in the middle of the inner end face of the cylinder body, a plurality of inwards-inclined holes are formed in the position, located on the periphery of the center shaft cavity, of the flow distribution surface in the circumferential direction, the inwards-inclined holes are communicated with the cylinder holes in a one-to-one correspondence mode and used for communicating the flow distribution windows with the cylinder holes, and the cylinder holes are plunger cavities. The inward inclined design of the orifice can effectively reduce the gaseous cavitation of the plunger cavity by utilizing the centrifugal effect of the rotating fluid. And a plurality of groups of micro pits are sequentially formed in the flow distribution surface from inside to outside, the forming efficiency and the bearing capacity of an oil film between the cylinder body and the flow distribution plate are effectively improved through the structure, the hydraulic overturning moment is balanced, and therefore the overturning degree of the cylinder body is relieved.

Description

Technical Field

[0001] The utility model relates to the technical field of axial piston pumps, and particularly relates to a cylinder block of a double-connected axial piston pump capable of resisting cylinder block overturning. Background Technique

[0002] With the continuous innovation and development of technology, and the change of market demand, axial piston pumps are gradually developing towards high rotational speeds. At the same time, problems such as the inclination of rotating components in axial piston pumps under high-speed operation are gradually emerging.

[0003] In the prior art, when an axial piston pump operates, there is a certain angle between the swash plate and the transmission shaft. At this time, due to the different lengths of the plungers remaining in the cylinder holes, the plunger shoe assemblies are unevenly distributed about the rotation center of the cylinder block in space, resulting in the plunger shoe assemblies rotating at high speed and reciprocating in the cylinder holes generating an overturning moment on the cylinder block. In addition, since the oil pressure in the plunger cavity at the high-pressure oil discharge window on the cylinder block is greater than the oil pressure in the plunger cavity at the low-pressure oil suction window, the cylinder block is subjected to a hydraulic overturning moment. The overturning moment will cause the cylinder block to overturn relative to the valve plate. The overturning of the cylinder block will form a wedge-shaped oil film between the cylinder block and the valve plate, resulting in an increase in its leakage flow rate and a sharp drop in the volumetric efficiency of the axial piston pump. At the same time, the inclination of the cylinder block greatly increases the probability of dry friction contact between the cylinder block and the valve plate, and also causes abnormal contact between the cylinder block and the transmission shaft. This will exacerbate the surface wear of related components and have a great impact on the performance and service life of the piston pump. Content of the Utility Model

[0004] The purpose of the utility model is to provide a cylinder block of a double-connected axial piston pump capable of resisting cylinder block overturning, and micro-pit texture treatment is carried out on the valve plate surface of the cylinder block by using surface laser texture technology. Its structure can effectively improve the formation efficiency and load-bearing capacity of the oil film between the cylinder block and the valve plate, balance the hydraulic overturning moment, and thus alleviate the degree of cylinder block overturning.

[0005] To achieve the above purpose, the utility model provides the following technical solution: a cylinder block of a double-connected axial piston pump capable of resisting cylinder block overturning, including a cylinder block. A plurality of spring connection holes are circumferentially arranged on the periphery of the central shaft cavity at the outer end of the cylinder block. A plurality of cylinder holes are circumferentially arranged at a position near the outer edge of the outer end of the cylinder block. A valve plate surface with a spherical concave structure is centrally arranged on the inner end surface of the cylinder block. A plurality of inwardly inclined orifices are circumferentially arranged at a position of the valve plate surface outside the central shaft cavity. The inwardly inclined orifices are in one-to-one correspondence and communication with the cylinder holes. The inwardly inclined orifices are used to connect the valve plate window and the cylinder holes. The cylinder holes are the plunger cavities. The inward inclination design of the orifices can effectively reduce the gaseous cavitation of the plunger cavity by using the centrifugal action of the rotating fluid. A plurality of groups of micro-pits are sequentially arranged on the valve plate surface from the inside to the outside. Its structure can effectively improve the formation efficiency and load-bearing capacity of the oil film between the cylinder block and the valve plate, balance the hydraulic overturning moment, and thus alleviate the degree of cylinder block overturning.

[0006] Preferably, the micro-pits in each group are evenly distributed circumferentially.

[0007] Preferably, the outer contour of the micro-pit is a rectangle with a length of 200 - 400 μm and a length-width ratio of 2 - 3, and the depth of the micro-pit is 20 - 30 μm.

[0008] Preferably, the distance between adjacent micro-pits is 200 - 300 μm.

[0009] Preferably, a boss is provided at the center of the outer end of the cylinder block, and a spline is provided on the inner peripheral wall of the central shaft cavity corresponding to the boss.

[0010] A dual-axial piston pump for resisting the overturning of the cylinder block includes an intermediate connector and housings fixedly docked at both ends of the intermediate connector. Front shafts and rear shafts are rotatably installed in the inner cavities of the two housings respectively. A spline sleeve is provided in the central cavity of the intermediate connector. The inner ends of the front shafts and the rear shafts are respectively sleeved in the spline sleeve. Distribution plates that are rotationally sleeved and matched with the front shafts and the rear shafts are respectively fixed on both sides of the intermediate connector. The cylinder block is sleeved on the front shafts and the rear shafts through the spline sleeve in the boss, and the distribution surface is attached to the outer side wall of the distribution plate. Plungers are respectively slidably sleeved in the cylinder bores. Brackets are respectively fixed at positions outside the cylinder block in the inner cavities of the housings. Swash plates are fixed in the brackets. A plurality of slippers are circumferentially attached to the inner side wall of the swash plate. A ball joint is connected between the slipper and the corresponding plunger. A compression spring connected to the ball joint is sleeved in the spring connection hole. There is a rotational angle of 0 - 20° between the two cylinder blocks in the circumferential direction.

[0011] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0012] 1. When the cylinder block of the dual-axial piston pump for resisting the overturning of the cylinder block involved in the present invention rotates at a high speed, the micro-pits provided on the distribution surface of the cylinder block can effectively improve the formation efficiency and load-bearing capacity of the oil film between the cylinder block and the distribution plate, so as to balance the hydraulic overturning moment, thereby alleviating the degree of cylinder block overturning.

[0013] 2. The dual-axial piston pump for resisting the overturning of the cylinder block involved in the present invention adopts a distribution method with a rotational angle between two cylinder blocks. By controlling the phase difference of the flow rate waveforms of the distribution windows of the front pump and the rear pump, when the flows merge at the pump outlet, the peaks and valleys of the two outlet flow rates are superimposed, realizing a significant reduction in the amplitude of the flow rate pulsation of the dual-axial piston pump, thereby reducing the intensity of the fluid noise excitation source of the dual-axial piston pump. Description of the Drawings

[0014] Figure 1 It is a schematic side view structure diagram of the cylinder block of the present invention;

[0015] Figure 2 This is a schematic cross-sectional view of the A-A section in the present utility model; Figure 1 in the present utility model;

[0016] Figure 3 This is a schematic enlarged view of the structure at position B in the present utility model; Figure 1 in the present utility model;

[0017] Figure 4 This is a schematic cross-sectional view of the split axial piston pump of the present utility model.

[0018] In the figure: 1 - front shaft;

[0019] 2 - bracket;

[0020] 3 - swash plate;

[0021] 4 - housing;

[0022] 5 - cylinder block; 5.1 - spring connection hole; 5.2 - boss; 5.3 - cylinder hole; 5.4 - porting surface; 5.5 - inclined port; 5.6 - micro pit;

[0023] 6 - intermediate connector;

[0024] 7 - rear shaft;

[0025] 8 - connecting sleeve;

[0026] 9 - port plate;

[0027] 10 - plunger;

[0028] 11 - slipper;

[0029] 12 - ball joint. Specific embodiments

[0030] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present utility model.

[0031] Please refer to Figures 1 - 3, the present utility model provides a technical solution: a double - acting axial piston pump cylinder block against cylinder block overturning, including a cylinder block 5. A plurality of spring connection holes 5.1 are circumferentially arranged around the outer peripheral of the central shaft cavity at the outer end of the cylinder block 5. A plurality of cylinder holes 5.3 are circumferentially arranged at a position near the outer edge of the outer end of the cylinder block 5. A distribution surface 5.4 with a spherical concave structure is arranged in the middle of the inner end surface of the cylinder block 5. A plurality of inward - inclined orifices 5.5 are circumferentially arranged at a position of the distribution surface 5.4 around the outer periphery of the central shaft cavity. The inward - inclined orifices 5.5 are in one - to - one correspondence and communication with the cylinder holes 5.3. Among them, the inward - inclined orifices 5.5 are used to connect the distribution window and the cylinder holes 5.3. The inward - inclined design of the inward - inclined orifices 5.5 can effectively reduce the gaseous cavitation of the cylinder holes by using the centrifugal action of the rotating fluid. A number of groups of micro - pits 5.6 are successively arranged on the distribution surface 5.4 from the inside to the outside. Among them, the micro - pits 5.6 in each group are evenly distributed circumferentially; the outer contour of the micro - pits 5.6 is a rectangle with a length of 200 - 400 μm and an aspect ratio of length to width of 2 - 3, and the depth of the micro - pits 5.6 is 20 - 30 μm; the distance between adjacent micro - pits 5.6 is 200 - 300 μm, which can effectively improve the formation efficiency and load - bearing capacity of the oil film between the cylinder block 5 and the distribution disc 9, balance the hydraulic overturning moment, and thus relieve the overturning degree of the cylinder block 5. A boss 5.2 is arranged at the center of the outer end of the cylinder block 5, and a spline is arranged on the inner peripheral wall of the central shaft cavity corresponding to the boss 5.2.

[0032] A double - acting axial piston pump against cylinder body overturning includes an intermediate connecting body 6 and housings 4 fixedly docked at both ends of the intermediate connecting body 6. The two housings 4 and their internal structures form a front pump and a rear pump. In the inner cavities of the two housings 4, a front shaft 1 and a rear shaft 7 are rotatably installed respectively. In the central cavity of the intermediate connecting body 6, there is a spline sleeve 8. The inner ends of the front shaft 1 and the rear shaft 7 are respectively sleeved in the spline sleeve 8. On both sides of the intermediate connecting body 6, there are respectively fixed distribution plates 9 that are rotationally sleeved and matched with the front shaft 1 and the rear shaft 7. The cylinder block 5 is sleeved on the front shaft 1 and the rear shaft 7 through the spline in the boss 5.2, and the distribution surface 5.4 is attached to the outer side wall of the distribution plate 9. In the cylinder bores 5.3, there are respectively slidably sleeved plungers 10. In the positions of the inner cavities of the housings 4 outside the cylinder block 5, there are respectively fixed brackets 2. In the brackets 2, there are fixed swash plates 3. Along the circumferential direction, the inner side walls of the swash plates 3 are attached with a plurality of slipper shoes 11. There are ball joints 12 connecting the slipper shoes 11 and the corresponding plungers 10. A compression spring connected with the ball joint 12 is sleeved in the spring connection hole 5.1. This enables the plunger 10 to perform reciprocating linear motion in the cylinder bore 5.3 while rotating around the front shaft 1 or the rear shaft 7. When the volume in the cylinder bore 5.3 expands, a vacuum is formed inside, and then hydraulic oil in the fuel tank is sucked from the oil suction window of the distribution plate 9. On the contrary, when the volume of the cylinder bore 5.3 decreases, the oil is discharged from the oil outlet window of the distribution plate 9 due to the increased pressure in the cylinder bore 5.3, thus completing the oil suction and oil discharge processes of the pump. During the oil distribution process, since the pressing force of the oil in the cylinder bore 5.3 at the high - pressure oil discharge window on the cylinder block 5 is greater than the pressing force of the oil in the cylinder bore 5.3 at the low - pressure oil suction window on the cylinder block 5, the cylinder block 5 is subjected to a hydraulic overturning moment. The micro - pits 5.6 formed on the distribution surface 5.4 of the cylinder block can effectively improve the formation efficiency and load - bearing capacity of the oil film between the cylinder block 5 and the distribution plate 9, balance the hydraulic overturning moment, and thus alleviate the overturning degree of the cylinder block 5.

[0033] The outlet flow rate of the axial piston pump has the characteristic of periodic pulsation: the minimum value of the pump outlet flow rate pulsation is distributed at the end of the pre - boosting stage of the plunger cavity, that is, at the moment when the cylinder bore 5.3 is about to complete the transition from low - pressure oil suction to high - pressure oil discharge; the maximum value of the pump outlet flow rate pulsation is distributed at the end of the pre - pressure - relief stage of the cylinder bore 5.3, that is, at the moment when the cylinder bore 5.3 is about to complete the transition from high - pressure oil discharge to low - pressure oil suction.

[0034] In order to achieve the confluence of outlet flow rates with different phases, the double - acting axial piston pump with a rotation angle θ has only one oil - suction port and one oil - discharge port. There is a rotation angle θ between the two cylinder blocks 5 in the circumferential direction, where θ = 0 - 20°. Due to the rotation angle θ between the two cylinder blocks 5 in the circumferential direction, the moments when the wave peaks and wave troughs of the outlet flow rates of the two pumps appear are different. By controlling the phase difference of the outlet flow rate waveforms of the front pump and the rear pump, when the flows confluence at the pump outlet, the wave peaks and wave troughs of the outlet flow rates of the two pumps are superimposed, achieving a significant reduction in the amplitude of the flow rate pulsation of the double - acting axial piston pump, thereby reducing the intensity of the fluid noise excitation source of the double - acting axial piston pump.

[0035] It should be noted that in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprising", "including" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device.

[0036] Although the embodiments of the present utility model have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principle and spirit of the present utility model. The scope of the present utility model is defined by the appended claims and their equivalents.

Claims

1. A cylinder block of a double - acting axial piston pump resistant to cylinder block overturning, comprising a cylinder block (5). Around the periphery of the central axis cavity at the outer end of the cylinder block (5), a plurality of spring connection holes (5.1) are provided circumferentially. At a position near the outer edge at the outer end of the cylinder block (5), a plurality of cylinder holes (5.3) are provided circumferentially. It is characterized in that: On the inner end face of the cylinder block (5) at the center, there is a distribution surface (5.4) with a spherical concave structure. At the position of the distribution surface (5.4) around the periphery of the central axis cavity, a plurality of inward - inclined orifices (5.5) are provided circumferentially. The inward - inclined orifices (5.5) are in one - to - one correspondence and communication with the cylinder holes (5.3); On the distribution surface (5.4), several groups of micro - pits (5.6) are provided in sequence from the inside to the outside.

2. The cylinder block of a double - acting axial piston pump for preventing cylinder block overturning according to claim 1, characterized in that: The micro - pits (5.6) within each group are evenly distributed circumferentially.

3. A cylinder block of a double - acting axial piston pump for preventing cylinder block overturning according to claim 1, characterized in that: The outer contour of the micro - pit (5.6) is a rectangle with a length of 200 - 400 μm and a length - width ratio of 2 - 3, and the depth of the micro - pit (5.6) is 20 - 30 μm.

4. A cylinder block of a double - acting axial piston pump for preventing cylinder block overturning according to claim 3, characterized in that: The distance between adjacent micro - pits (5.6) is 200 - 300 μm.

5. The cylinder block of a double - acting axial piston pump against cylinder block overturning according to claim 4, characterized in that: At the center of the outer end of the cylinder block (5), there is a boss (5.2), and a spline is provided on the inner peripheral wall of the central axis cavity corresponding to the boss (5.2).

6. A double-acting axial piston pump for preventing the cylinder block from tipping over, characterized in that, Including the cylinder block (5) as described in claim 5, it further includes an intermediate connector (6) and housings (4) fixedly docked at both ends of the intermediate connector (6). In the inner cavities of the two housings (4), a front shaft (1) and a rear shaft (7) are respectively rotatably installed. In the central cavity of the intermediate connector (6), there is a spline sleeve (8). The inner ends of the front shaft (1) and the rear shaft (7) are respectively sleeved in the spline sleeve (8). On both sides of the intermediate connector (6), distribution discs (9) fixedly matched with the front shaft (1) and the rear shaft (7) for rotational sleeving are respectively fixed. The cylinder block (5) is sleeved on the front shaft (1) and the rear shaft (7) through the spline sleeve in the boss (5.2), and the distribution surface (5.4) is attached to the outer side wall of the distribution disc (9). Plungers (10) are respectively slidably sleeved in the cylinder holes (5.3). At positions outside the cylinder block (5) in the inner cavities of the housings (4), brackets (2) are respectively fixed. In the brackets (2), swash plates (3) are fixed. Along the circumference, a plurality of slipper shoes (11) are attached to the inner side wall of the swash plate (3). A ball joint (12) is connected between the slipper shoe (11) and the corresponding plunger (10). Compression springs connected to the ball joint (12) are sleeved in the spring connection holes (5.1). There is a rotation angle of 0 - 20° between the two cylinder blocks (5) in the circumferential direction.

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