Axial plunger pump with fixed-clearance return stroke structure

Abstract

The utility model relates to an axial plunger pump, in particular to an axial plunger pump with a fixed clearance return stroke structure, which comprises a main shaft, a swash plate, a sliding shoe, a return stroke plate, a pressing plate and a clearance adjusting ring. A boss is formed on the swash plate, a through hole is formed in the pressing plate, abutting portions are formed at the two ends of the pressing plate, and the gap adjusting ring is located between the pressing plate and the boss and fixed through screws. Compared with the prior art, inclination and eccentric wear of the sliding shoes caused by inertia force are avoided, so that wear of the sliding shoes and the swash plate is remarkably reduced, and the service life of the plunger pump is prolonged.

Description

TECHNICAL FIELD

[0001] The utility model relates to an axial plunger pump, in particular to an axial plunger pump with a constant-clearance return structure. BACKGROUND

[0002] As an important form of volumetric pumps, axial plunger pumps are widely used in industrial fields such as hydraulic systems, lubrication systems, fuel supply systems, etc. It forces the plunger to make reciprocating motion in the cylinder plunger cavity through the relative rotation between the swash plate and the cylinder, thereby realizing the periodic change of the working volume. In this process, the matching of the matching device enables the pump to complete the suction and discharge of the working medium, thereby achieving the purpose of conveying fluid.

[0003] However, the existing axial plunger pump has some technical problems when running at high speed. In particular, the center spring return device used in the plunger pump may not be able to ensure that the slipper bottom surface always tightly contacts the swash plate under the influence of inertial force. This unstable contact can cause the slipper to tilt and the outer edge to wear unevenly, and in severe cases, the slipper may even come off the swash plate. In addition, the spring force of the return device acts on each slipper, which not only increases the pressure of the slipper on the swash plate, but also is not conducive to reducing wear, but may even exacerbate the degree of wear. In the plunger pump, the commonly used ball wrapping structure between the plunger ball head and the slipper is prone to slipper or loose ball phenomenon due to the large friction between the plunger and the seal and between the plunger and the cylinder sleeve. The integrated structure of the plunger and its ball head also limits the flexibility of material selection for the friction pairs such as the plunger and the cylinder sleeve, and the ball head and the slipper. These factors not only affect the working efficiency of the plunger pump, but also reduce its working reliability, limiting its use in some high-performance application scenarios. SUMMARY

[0004] In view of the above defects or one of the defects of the prior art, the utility model provides an axial plunger pump with a constant-clearance return structure, which aims to improve the friction and thermal wear in the plunger pump and improve the working performance, stability and reliability of the plunger pump. To this end, the technical scheme adopted by the utility model is:

[0005] An axial piston pump with a constant clearance return structure, comprising a main shaft, a swash plate sleeved on the main shaft, a plurality of shoes in abutment with the working surface of the swash plate, and a return plate in abutment with the plurality of shoes, different from the prior art, two pressure plates and four gap adjusting rings are added; the working surface of the swash plate outside the return plate extends upward to form four bosses, and a threaded hole is formed on each boss; a through hole corresponding to the threaded hole formed on the adjacent two bosses is formed on each pressure plate, and a pressing portion capable of pressing the return plate is formed on both ends of each pressure plate, and an avoiding portion not interfering with the plunger is formed between the two pressing portions; the gap adjusting ring is located between the two pressure plates and the four bosses, and four screws are respectively screwed into the four threaded holes on the four bosses through the four through holes on the two pressure plates and the four gap adjusting rings.

[0006] Further, the thicknesses of the four gap adjusting rings are equal and related to the thickness of the return plate and the preset gap.

[0007] Further, the lower surface of the return plate is in abutment with the shoe bottom portion of the shoe.

[0008] Further, a via hole equal in number to the shoes is formed on the return plate, and the shoe neck portion passes through the via hole, and the diameter of the via hole is greater than the diameter of the shoe neck portion and less than the diameter of the shoe bottom portion.

[0009] Further, a center hole is formed in the center of the return plate, which can pass through the main shaft and does not interfere with the main shaft when the swash plate swings.

[0010] Further, a ball socket is formed on the return plate outside the center hole, which is in sliding fit with the spherical surface of the ball hinge.

[0011] Compared with the prior art, the beneficial technical effects of the utility model mainly reflect in the following aspects:

[0012] 1. Reduce wear and prolong service life: by introducing a constant clearance return structure, the contact between the shoe and the swash plate is more stable, and the inclination and eccentric wear of the shoe caused by inertial force are avoided, thereby significantly reducing the wear of the shoe and the swash plate, and prolonging the service life of the piston pump.

[0013] 2. Improve the stability of the work: the constant clearance return structure ensures that the shoe always contacts the swash plate during the return stroke of the plunger, avoids the problem of unstable pump operation caused by uneven spring force or shoe disengagement from the swash plate, and improves the working stability of the piston pump under high speed or variable load conditions.

[0014] 3. Reduced operating noise: By reducing the friction and wear between the shoe and swash plate, the vibration and noise generated during the operation of the plunger pump are reduced, improving the working environment and reducing the potential impact on other equipment.

[0015] 4. Optimized material selection: The design of the present utility model allows more flexible selection of materials for friction pairs such as plungers, cylinder sleeves, ball heads and shoes, as the structure of the pressure plate and the gap adjusting ring reduces the dependence on integrated structures, allowing for optimized selection based on specific working conditions and material properties.

[0016] 5. Simplified maintenance and reduced costs: Due to reduced wear, the maintenance cycle of the plunger pump is extended, reducing maintenance costs. At the same time, the improved structural design also makes maintenance and replacement of parts more convenient, further reducing maintenance costs.

[0017] 6. Improved pump reliability: By reducing wear between the shoe and swash plate and improving operational stability, the overall reliability of the plunger pump is improved, reducing the risk of production interruptions due to pump failures and improving the continuity and efficiency of industrial production.

[0018] 7. Strong adaptability: The plunger pump design of the present utility model can adapt to a wider range of working conditions, including high pressure, high speed and high temperature, etc. harsh environments, enhancing the applicability and market competitiveness of the pump.

[0019] In summary, the present utility model effectively solves the problems existing in the prior art through innovative fixed-gap return structure design, providing a new technical solution for performance improvement and application expansion of axial plunger pumps. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is a structural schematic diagram of the present utility model.

[0021] Figure 2 is a structural schematic diagram of the swash plate of the present utility model.

[0022] Figure 3 is a structural schematic diagram of the return plate of the present utility model.

[0023] Figure 4 is a structural schematic diagram of the ball hinge of the present utility model.

[0024] Figure 5 is a structural schematic diagram of the shoe of the present utility model.

[0025] Figure 6 is a structural schematic diagram of the pressure plate of the present utility model.

[0026] Figure 7 is a structural schematic diagram of the gap adjusting ring of the present utility model. DETAILED DESCRIPTION

[0027] In the description of the utility model, it needs to explain, the term "center", "upper", "lower", "left", "right", "vertical", "horizontal", "internal", "external" and so on indicate the orientation or position relation is based on the orientation or position relation shown in the drawing, only for the convenience of describing the utility model and simplifying the description, and not indicate or imply that the device or element must have a particular orientation, construct and operate in a particular orientation, therefore, it cannot be understood as a limitation on the utility model.

[0028] In the description of the utility model, it needs to explain, unless otherwise expressly provided and limited, the term "installation", "connection", "communication" should be understood broadly, for example, it can be fixed connection, can also be detachable connection, or integrally connected, can be mechanical connection, can also be electrical connection, can be directly connected, can also be indirectly connected through the intermediate medium, can be the communication inside two elements. For ordinary skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

[0029] The following specific embodiments illustrate the embodiments of the utility model, and those skilled in the art can easily understand other advantages and effects of the utility model from the contents disclosed in the specification. Obviously, the described embodiments are part of the embodiments of the utility model, not all. Based on the embodiments in the utility model, all other embodiments obtained by ordinary skilled in the art without creative labor belong to the scope of protection of the utility model.

[0030] As Figures 1-7 The utility model discloses an axial plunger pump with fixed gap return structure, an axial plunger pump with fixed gap return structure, including main shaft 1, the swash plate 2 of setting on the main shaft 1, with the working face 21 of the swash plate 2 abuts on multiple slide shoes 3, with multiple the return disc 4 of abutting on the slide shoe 3, increase 2 pressure plate 5 and 4 gap adjusting ring 7, the working face 21 of the swash plate 2 outside the return disc 4 extends upwards and forms 4 bosses 22, the threaded hole 23 is set up on each boss 22, the through hole 51 corresponding with the threaded hole 23 set up on adjacent two bosses 22 is set up on each pressure plate 5, the abutting portion 52 capable of abutting the return disc 4 is formed to the inward extension of both ends of each pressure plate 5, the avoiding portion 53 not interfering with plunger 6 is formed to the outward retraction between 2 abutting portions 52, the gap adjusting ring 7 is located between 2 pressure plate 5 and 4 bosses 22 respectively, and 4 screws 8 are respectively screwed with 4 threaded holes 23 on 4 bosses 22 after passing through 4 through holes 51 on 2 pressure plate 5 and 4 gap adjusting rings 7.

[0031] The working principle is briefly described as follows:

[0032] 1. Main shaft drive: When the main shaft 1 starts rotating, power is transmitted to the swash plate 2 through the main shaft. The swash plate 2 is fixedly connected with the main shaft 1 and rotates with it.

[0033] 2. Interaction between swash plate and shoe: The working surface 21 of the swash plate 2 abuts against multiple shoes 3. The shoes 3 are installed on the top of the plunger, and the rotation of the swash plate 2 forces the shoes 3 to slide along the surface inside the cylinder plunger cavity, thereby pushing the plunger to reciprocate.

[0034] 3. Reciprocating motion of plunger: The plunger reciprocates in the plunger cavity, and its motion is controlled by the power transmitted by the swash plate 2 through the shoes 3. The reciprocating motion of the plunger changes the volume of the working chamber, thereby realizing the functions of suction and discharge of working medium.

[0035] 4. Action of return plate and pressure plate: The return plate 4 abutted by the shoes 3 is used to provide stable support for the shoes during the return stroke of the plunger. The pressure plate 5 is fixed with the swash plate 2 through the through hole 51 and the screw hole 23, and its abutting part 52 exerts pressure on the return plate 4, ensuring that the shoes 3 remain in contact with the swash plate 2 during the return stroke.

[0036] 5. Adjustment of gap adjustment ring: The gap adjustment ring 7 is located between the pressure plate 5 and the boss 22, and by adjusting the position of the gap adjustment ring 7, the gap between the shoes 3 and the swash plate 2 can be adjusted to adapt to different working conditions and wear conditions.

[0037] 6. Fixing effect of screw: The screw 8 passes through the through hole 51 on the pressure plate 5 and the gap adjustment ring 7, and is screwed with the screw hole 23 on the boss 22, fixing the entire structure and ensuring that the positional relationship between the components remains unchanged during pump operation.

[0038] 7. Suction and discharge process: Under the drive of the main shaft 1, the reciprocating motion of the plunger causes the volume of the working chamber to change periodically, and in combination with the flow distribution device, the suction and discharge of the working medium are realized. When the plunger is pulled back, the volume of the working chamber increases, creating a negative pressure to suck in the working medium; when the plunger is pushed forward, the volume of the working chamber decreases, and the pressure increases to discharge the working medium.

[0039] Through this design, the axial plunger pump can provide stable and efficient fluid delivery while reducing energy consumption and maintenance requirements due to friction and wear, improving the working performance, stability and reliability of the pump.

[0040] In this embodiment, the thickness of the four gap adjustment rings 7 is equal and is related to the thickness of the backcheck disc 4 and the predetermined gap. By ensuring that the thickness of all gap adjustment rings 7 is equal, a consistent preload force can be provided throughout the system, ensuring that the contact pressure between the shoes 3 and the swash plate 2 is evenly distributed, enhancing the reliability of the system. By precisely designing the thickness of the gap adjustment rings 7, the predetermined gap between the shoes 3 and the swash plate 2 can be precisely controlled. This is crucial for maintaining the optimal performance of the pump, as too large a gap can lead to leakage, while too small a gap can result in excessive wear. If the thickness of all gap adjustment rings 7 is equal, when adjusting and maintaining the system, these rings can be quickly replaced or repositioned without the need to individually adjust the thickness of each ring, reducing the time for maintenance and adjustment. Relating the thickness of the gap adjustment rings 7 to the thickness of the backcheck disc 4 and the predetermined gap allows the designer to optimize the design of the entire system for optimal performance. This optimization can take into account factors such as wear and aging at the design stage, extending the service life of the pump. By maintaining the appropriate gap, energy consumption due to friction and wear can be reduced, improving the efficiency of the pump. The appropriate gap ensures smooth sliding of the shoes 3 on the swash plate 2, reducing energy loss. The standardized gap adjustment ring 7 design simplifies the manufacturing process and allows maintenance personnel to easily identify and replace worn parts without the need for complex measurements or custom-made parts. By precisely controlling the gap, the pump can better adapt to different working conditions and medium characteristics, maintaining high efficiency and reliable performance in a wider range of applications. Overall, this design improves the performance, stability, and maintenance convenience of the axial piston pump by ensuring the consistency and controllability of the gap.

[0041] In this embodiment, the lower surface of the backcheck disc 4 is in abutment with the shoe bottom portion 32 of the shoes 3. The abutment of the lower surface of the backcheck disc 4 with the shoe bottom portion 32 of the shoes 3 provides stable support for the shoes. This design ensures smooth sliding of the shoes during the piston backstroke, reducing wear and damage caused by unstable movement of the shoes.

[0042] In this embodiment, the return disc 4 is provided with through holes 41 equal in number to the number of the shoes 3, through which the shoe necks 31 of the shoes 3 pass, and the diameter of the through holes 41 is greater than the diameter of the shoe necks 31 and less than the diameter of the shoe bottoms 32. The number of the through holes 41 provided on the return disc 4 is equal to the number of the shoes 3, allowing the shoe necks 31 to pass through. The diameter of the through holes 41 is designed to be greater than the diameter of the shoe necks 31 but less than the diameter of the shoe bottoms 32, which not only ensures the free movement of the shoes but also limits the excessive movement of the shoes, maintaining the correct alignment between the shoes and the return disc. The dynamic characteristics between the return disc 4 and the shoes 3 are optimized. The shoe necks 31 of the shoes move freely in the through holes 41, while the shoe bottoms 32 are supported by the lower surface of the return disc, which not only guarantees the stability of the shoes but also allows the necessary flexibility to adapt to the operation of the pump under different working conditions.

[0043] In this embodiment, the center of the return disc 4 is provided with a central hole 42 through which the main shaft 1 passes and which does not interfere with the main shaft 1 when the swash plate 2 swings. The return disc 4 is provided with a ball socket 43 on the outside of the central hole 42, which is in sliding fit with the spherical surface of the spherical hinge 9. The central hole 42 provided in the center of the return disc 4 allows the main shaft 1 to pass through and does not interfere with the main shaft 1 when the swash plate 2 swings with the main shaft 1. This design ensures the free rotation of the main shaft and the swash plate, while ensuring the coordinated operation of the return disc and the entire pump system. The ball socket 43 on the return disc 4 is in sliding fit with the spherical surface of the spherical hinge 9, providing a flexible connection. This fit allows the return disc to swing with the swash plate within a certain range, while absorbing the impact force and vibration generated by the operation of the pump, thereby protecting the precision components of the pump and prolonging its service life. The design of the return disc 4 makes it easier to maintain and replace the shoes 3. Due to the fit design of the through holes 41 and the shoe necks 31, the shoes can be quickly disassembled and installed, reducing maintenance time and cost.

[0044] Although the utility model has been described in detail above with general description and specific embodiments, some modifications or improvements can be made on the basis of the utility model, which is obvious to those skilled in the art. Therefore, these modifications or improvements made on the basis of not deviating from the spirit of the utility model, all belong to the scope of protection required by the utility model.

[0045] The parts not described in detail in the utility model are the existing technology or common knowledge in the art.

Claims

1. An axial piston pump having a constant gap return structure, comprising a main shaft (1), a swash plate (2) fitted on the main shaft (1), a plurality of shoes (3) abutting against a working surface (21) of the swash plate (2), a return plate (4) abutting against the plurality of shoes (3), characterized in that, Two pressing plates (5) and four gap adjusting rings (7) are added; the working surface (21) of the swash plate (2) outside the return plate (4) extends upward to form four bosses (22), and a threaded hole (23) is formed in each boss (22); a through hole (51) corresponding to the threaded hole (23) formed in the adjacent two bosses (22) is formed in each pressing plate (5), and a pressing portion (52) capable of pressing the return plate (4) is formed at both ends of each pressing plate (5) and extends inwardly, two pressing portions (52) are retracted outwardly to form a gap (53) that does not interfere with the plunger (6), the gap adjusting ring (7) is located between the two pressing plates (5) and the four bosses (22), and four screws (8) are respectively screwed into the four threaded holes (23) on the four bosses (22) through the four through holes (51) on the two pressing plates (5) and the four gap adjusting rings (7).

2. An axial piston pump with a constant gap return structure according to claim 1, characterized in that The thicknesses of the four gap adjusting rings (7) are equal and related to the thickness of the return plate (4) and the preset gap.

3. An axial piston pump with a constant gap back structure according to claim 1, characterized in that The lower surface of the return plate (4) abuts against the sole portion (32) of the shoe (3).

4. An axial piston pump with a constant gap back structure according to claim 1, characterized in that A via hole (41) equal in number to the shoes (3) is formed in the return plate (4), and the shoe neck portion (31) of the shoe (3) passes through the via hole (41), the diameter of the via hole (41) is greater than the diameter of the shoe neck portion (31) and less than the diameter of the sole portion (32).

5. An axial piston pump with a constant gap back structure according to claim 1, characterized in that, A center hole (42) is formed in the center of the return plate (4) to pass through the main shaft (1) and not interfere with the main shaft (1) when the swash plate (2) swings.

6. An axial piston pump with a constant gap return structure according to claim 5, characterized in that A ball socket (43) is formed in the return plate (4) outside the center hole (42) to slidably cooperate with the spherical surface of the ball hinge (9).

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