A high-speed oscillating disc axial piston pump

Abstract

This invention relates to the field of hydraulic transmission technology and discloses a high-speed swashplate axial piston pump, comprising a drive shaft and a piston cylinder. A drive swashplate is fixedly connected to the outside of the drive shaft, and the drive shaft and drive swashplate are integrally designed with the drive swashplate tilted. Both the drive shaft and drive swashplate are located inside the piston cylinder, with one end of the drive shaft extending to the outside of the piston cylinder. A needle roller bearing is installed inside the piston cylinder, with the outer side of the drive shaft fitting against the inner side of the needle roller bearing. The drive shaft is rotatably connected to the piston cylinder via the needle roller bearing. A swashplate is disposed outside the drive swashplate, and two thrust bearings are installed on both sides of the outer side of the swashplate. The axial piston pump of this invention abandons the traditional slipper-swashplate configuration, avoiding the problems of slipper slipper detachment or overturning caused by centrifugal force under high-speed conditions, which leads to piston pump wear, sticking, power loss, or even failure.

Description

Technical Field

[0001] This invention relates to the field of hydraulic transmission technology, specifically to a high-speed oscillating disc axial piston pump. Background Technology

[0002] In the core components of a hydraulic system, the hydraulic pump, as a key element for power output, directly determines the operating efficiency and reliability of the entire system. Axial piston pumps, with their superior performance characteristics, occupy a crucial position among various types of hydraulic pumps. Compared with other types such as gear pumps and vane pumps, axial piston pumps have significant advantages such as high working pressure, compact structure, high volumetric efficiency, and convenient flow adjustment. Therefore, they are widely used in aerospace, engineering machinery, shipbuilding, precision machine tools, and other fields with stringent power performance requirements. In aviation hydraulic systems, axial piston pumps provide stable power for critical actions such as landing gear retraction and extension, control surface deflection, and engine accessory drive. Currently, mainstream axial piston pumps in the industry generally adopt the classic structure of swashplate-slipper-piston assembly-rotating cylinder. The working principle of this structure is based on the relative motion between the swashplate and the rotating cylinder: when the drive shaft drives the rotating cylinder to rotate, the piston assembly inside the cylinder reciprocates along the cylinder's axial direction under the constraint of the slipper. During the suction stroke, the piston extends outward under the guidance of the slipper and swashplate, creating a negative pressure in the piston bore of the cylinder, and hydraulic oil is drawn in through the suction window of the distributor plate. During the pressure stroke, the piston contracts inward under the pressure of the swashplate, expelling high-pressure oil through the pressure window of the distributor plate. The slipper, as a key force transmission component between the piston and the swashplate, not only bears the axial force transmitted by the piston but also achieves lubrication and sealing through the oil film between itself and the swashplate. Simultaneously, it reciprocates along the swashplate surface while rotating with the cylinder, forming a complex composite motion trajectory. However, this traditional configuration reveals insurmountable technical flaws in high-speed operation scenarios. In hydraulic systems driven by aero-engines, when the axial piston pump rotates at excessively high speeds, the slipper is subjected to enormous centrifugal force, causing a sharp increase in the contact pressure between it and the swashplate. This easily damages the boundary lubrication film, resulting in direct metal-to-metal contact friction. The instantaneous localized high temperatures cause thermal decomposition of the lubricating oil film, further exacerbating the wear of the friction pair. In addition, while rotating with the cylinder, the slipper also needs to reciprocate along the swashplate's inclined surface. This combined motion at high speeds can cause dynamic imbalance in the slipper—when the speed exceeds the design threshold, the slipper momentarily detaches from the swashplate surface and then re-impacts the swashplate under the piston thrust, generating strong vibrations and impacts. This periodic detachment and impact not only leads to severe wear on the contact surface between the slipper and the swashplate but also causes the piston to wobble violently within the cylinder, resulting in unstable sealing clearance between the piston and the cylinder, leading to hydraulic oil leakage and reduced volumetric efficiency. In extreme cases, the radial force generated by the plunger's sway exceeds the bearing capacity of the seal, leading to seal failure. This results in problems such as increased flow pulsation and system pressure fluctuations. Furthermore, during the oil suction phase, excessively high local vacuum can trigger cavitation, causing cavitation damage. Ultimately, this leads to viscous jamming and a surge in power loss in the axial plunger pump, eventually resulting in complete failure. Therefore, this invention provides a high-speed swaying disc axial plunger pump to address the shortcomings of existing technologies. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides a high-speed swivel disc axial piston pump, which solves the problems mentioned in the background section.

[0004] To achieve the above objectives, the present invention provides the following technical solution: A high-speed swashplate axial piston pump includes a drive shaft and a piston cylinder. A drive swashplate is fixedly connected to the outside of the drive shaft. The drive shaft and the drive swashplate are integrally designed, and the drive swashplate is inclined. Both the drive shaft and the drive swashplate are located inside the piston cylinder. One end of the drive shaft extends to the outside of the piston cylinder. A needle roller bearing is installed inside the piston cylinder. The outer side of the drive shaft fits against the inner side of the needle roller bearing, and the drive shaft is rotatably connected to the piston cylinder through the needle roller bearing. A swashplate is provided outside the drive swashplate. Two thrust bearings are installed on both outer sides of the swashplate. The swashplate is mounted outside the drive swashplate through the two thrust bearings. An anti-rotation rod is fixedly connected to the inner wall of the piston cylinder. The bottom of the swashplate is connected to the outer side of the anti-rotation rod. The anti-rotation rod is used to prevent the swashplate from rotating. The device rotates radially. Seven sets of grooves are provided on one side of the swing plate, and a high-precision bidirectional ball joint connecting rod is connected inside each groove. Seven sets of plunger chambers are provided inside the plunger cylinder. A plunger assembly is slidably connected to the inner side of each plunger chamber. One end of the high-precision bidirectional ball joint connecting rod is connected to one end of the plunger assembly. A distribution plate is provided at one end of the plunger cylinder. The plunger cylinder and the distribution plate are connected by a seal. A housing is installed outside the distribution plate, and the housing is connected to one end of the plunger cylinder. An angular contact bearing is installed between the housing and the distribution plate. A spline is provided at the other end of the drive shaft. A distribution shaft is installed inside the distribution plate. One end of the distribution shaft is located inside the plunger cylinder, and the other end of the drive shaft is connected to one end of the distribution shaft via a spline. Oil inlet and outlet channels are distributed centrally inside the distribution shaft, and these channels communicate with the plunger chambers. Distribution windows are provided on the distribution shaft, distribution plate, and angular contact bearing for oil flow.

[0005] This invention provides a high-speed oscillating disc axial piston pump. It has the following beneficial effects: 1. The axial piston pump of the present invention abandons the traditional slipper-swashplate configuration, avoiding the problem of slipper slipper detachment or overturning caused by centrifugal force under high speed conditions, which leads to wear, sticking, power loss or even failure of the piston pump.

[0006] 2. The bidirectional ball joint connecting rod structure of the present invention optimizes the movement trajectory of the plunger assembly, effectively reducing the large plunger sway amplitude, large plunger radial force, low sealing reliability, unstable flow, and even cavitation phenomena caused by the unidirectional ball joint connecting rod in the traditional configuration.

[0007] 3. The configuration of this invention effectively improves the service life of the piston pump, has higher power density, is applicable to a wider speed range, comprehensively improves the overall performance of the piston pump, and promotes the iterative upgrading of aviation hydraulic system technology. Attached Figure Description

[0008] Figure 1 This is a cross-sectional view of the present invention.

[0009] The components include: 1. Drive shaft; 2. Drive swashplate; 3. Thrust bearing; 4. Swing plate; 5. Anti-rotation rod; 6. High-precision bidirectional ball joint connecting rod; 7. Piston assembly; 8. Piston cylinder; 9. Needle roller bearing; 10. Distribution shaft; 11. Distribution plate; 12. Angular contact bearing; and 13. Housing. Detailed Implementation

[0010] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0011] Please see the appendix Figure 1This invention provides a high-speed swashplate axial piston pump, comprising a drive shaft 1 and a piston cylinder 8. A drive swashplate 2 is fixedly connected to the outside of the drive shaft 1. The drive shaft 1 and the drive swashplate 2 are integrally designed, and the drive swashplate 2 is inclined. Both the drive shaft 1 and the drive swashplate 2 are located inside the piston cylinder 8. One end of the drive shaft 1 extends to the outside of the piston cylinder 8. A needle roller bearing 9 is installed inside the piston cylinder 8. The outer side of the drive shaft 1 is in contact with the inner side of the needle roller bearing 9, and the drive shaft 1 is rotatably connected to the piston cylinder 8 through the needle roller bearing 9. A swashplate 4 is provided outside the drive swashplate 2. Two thrust bearings 3 are installed on both sides of the outer side of the swashplate 4. The swashplate 4 is mounted outside the drive swashplate 2 through the two thrust bearings 3. An anti-rotation rod 5 is fixedly connected to the inner wall of the piston cylinder 8. The bottom of the swashplate 4 is connected to the outer side of the anti-rotation rod 5. The anti-rotation rod 5 is used to prevent the swashplate 4 from rotating radially. One side of the swashplate 4 is open. The plunger cylinder 8 has seven sets of grooves, and a high-precision bidirectional ball joint connecting rod 6 is connected inside each groove. The plunger cylinder body 8 has seven sets of plunger cavities inside, and a plunger assembly 7 is slidably connected to the inner side of each plunger cavity. One end of the high-precision bidirectional ball joint connecting rod 6 is connected to one end of the plunger assembly 7. A distribution plate 11 is provided at one end of the plunger cylinder body 8. The plunger cylinder body 8 and the distribution plate 11 are connected by a seal. A housing 13 is installed outside the distribution plate 11, and the housing 13 is connected to one end of the plunger cylinder body 8. An angular contact bearing 12 is installed between the drive shaft 13 and the distribution plate 11. A spline is provided at the other end of the drive shaft 1. A distribution shaft 10 is installed inside the distribution plate 11. One end of the distribution shaft 10 is located inside the plunger cylinder 8. The other end of the drive shaft 1 is connected to one end of the distribution shaft 10 through a spline. Oil inlet and outlet channels are distributed in the center of the distribution shaft 10 and are connected to the plunger cavity. Distribution windows are opened on the distribution shaft 10, the distribution plate 11 and the angular contact bearing 12 for the flow of oil.

[0012] Specifically, the drive shaft 1, as the main shaft, is integrated with the drive swashplate 2. The swashplate plane and the cylinder block plane form a certain angle. The swashplate 4 is connected to the drive swashplate 2 through a thrust bearing 3. The right side of the swashplate 4 is also equipped with a thrust bearing 3, which is axially fixed by bearing end caps and bolts. The bottom end of the swashplate 4 is connected to the anti-rotation rod 5 through a gear ring, which can prevent the swashplate 4 from rotating radially. Seven sets of ball joint structures are evenly distributed on the swashplate 4, and seven sets of plunger cavities are evenly distributed on the plunger cylinder block 8. The swashplate 4 is connected to the plunger assembly 7 through a high-precision bidirectional ball joint connecting rod 6, and then connected to the plunger cylinder block 8 through the plunger cavity.

[0013] Working principle: First, the external motor is started, which drives the drive shaft 1 and drive swashplate 2 to rotate. Since the swashplate 4 is connected to the anti-rotation rod 5, the rotation of the drive shaft 1 prevents the swashplate 4 from rotating radially. The inclined surface design of the drive swashplate 2 causes the swashplate 4 to oscillate circumferentially during rotation, which in turn causes the high-precision bidirectional ball joint connecting rod 6 connected to it to oscillate back and forth, forcing the plunger assembly 7 to perform linear reciprocating motion within the plunger cavity. This avoids the large radial force generated by the ball joint connecting rod during high-speed rotation in traditional configurations, which could cause sealing failure and efficiency reduction between the plunger assembly 7 and the plunger cavity. Furthermore, unlike conventional plunger pumps, because the swashplate 4... There is no radial rotational motion. During the entire movement, the plunger cylinder 8 of this configuration does not rotate and remains stationary. The plunger cylinder 8 is connected to the distribution plate 11 through a sealing assembly and to the drive shaft 1 through a needle roller bearing 9. The drive shaft 1 is connected to the distribution shaft 10 through a spline. The distribution shaft 10 has oil inlet and outlet channels distributed in the center. By opening distribution windows on the distribution shaft 10, the distribution plate 11 and the housing 13, when the inclined surface of the drive swashplate 2 rotates to the upper end, the upper plunger assembly draws oil from the oil inlet to the distribution shaft 10, and then enters the cavity through the distribution plate 11. The lower plunger assembly presses oil to the distribution plate 11, and then to the oil outlet through the distribution shaft 10.

Claims

1. A high-speed oscillating disc axial piston pump, characterized in that, The device includes a drive shaft (1) and a plunger cylinder (8). A drive swashplate (2) is fixedly connected to the outside of the drive shaft (1). The drive shaft (1) and the drive swashplate (2) are designed as a single unit, and the drive swashplate (2) is tilted. Both the drive shaft (1) and the drive swashplate (2) are located inside the plunger cylinder (8). One end of the drive shaft (1) extends to the outside of the plunger cylinder (8). A needle roller bearing (9) is installed inside the plunger cylinder (8). The outer side of the drive shaft (1) is in contact with the inner side of the needle roller bearing (9), and the drive shaft (1) is connected to the plunger cylinder (8) via the needle roller bearing (9). The piston cylinder body (8) is rotatably connected; a swing plate (4) is provided on the outside of the drive swashplate (2), and two thrust bearings (3) are installed on the outer sides of the swing plate (4). The two thrust bearings (3) are installed on the outer sides of the drive swashplate (2), and the swing plate (4) is installed on the outside of the drive swashplate (2) through the two thrust bearings (3); an anti-rotation rod (5) is fixedly connected to the inner wall of the piston cylinder body (8), and the bottom of the swing plate (4) is connected to the outer side of the anti-rotation rod (5). The anti-rotation rod (5) is used to prevent the swing plate (4) from rotating radially; one side of the swing plate (4) is opened There are seven sets of grooves, and a high-precision bidirectional ball joint connecting rod (6) is connected inside the grooves. The plunger cylinder body (8) has seven sets of plunger cavities inside. A plunger assembly (7) is slidably connected to the inner side of the plunger cavity. One end of the high-precision bidirectional ball joint connecting rod (6) is connected to one end of the plunger assembly (7). A distribution plate (11) is provided at one end of the plunger cylinder body (8). The plunger cylinder body (8) and the distribution plate (11) are connected by a seal. A housing (13) is installed on the outside of the distribution plate (11), and the housing (13) is connected to one end of the plunger cylinder body (8). (13) An angular contact bearing (12) is installed between the drive shaft (1) and the distribution plate (11); a spline is provided at the other end of the drive shaft (1); a distribution shaft (10) is installed inside the distribution plate (11); one end of the distribution shaft (10) is located inside the plunger cylinder (8); the other end of the drive shaft (1) is connected to one end of the distribution shaft (10) through a spline; an oil inlet and outlet channel is distributed in the center of the distribution shaft (10), and the oil inlet and outlet channel is connected to the plunger cavity; distribution windows are opened on the distribution shaft (10), the distribution plate (11) and the angular contact bearing (12) for the flow of oil.

Images