Transmission structure of shaft and cylinder body of axial plunger pump

Abstract

The invention relates to the technical field of axial plunger pumps, in particular to a transmission structure of a shaft and a cylinder body of an axial plunger pump, a transmission unit comprises a valve plate fixedly arranged on an input shaft, the valve plate and a rotary cylinder body are attached to each other, a material distribution groove is formed in the valve plate, a cylinder groove is formed in the rotary cylinder body, a feeding port is formed in the bottom end of the cylinder groove, and a discharging port is formed in the bottom end of the cylinder groove. The characteristics that the mechanism is simple, the number of parts is small, manufacturing and assembling are convenient, durability is good and the like are achieved, in the low-speed motion state, the speed conversion non-uniformity is reduced, in the high-speed motion state, the speed conversion non-uniformity is reduced, and the speed conversion efficiency is improved. According to the transmission mechanism of the shaft and the cylinder body of the axial plunger pump, the situation that the torque transmission capacity is reduced due to the fact that the abrasion gap between the flexible pin shaft and the rotary cylinder body is enlarged is avoided, the good dynamic performance of the hydraulic pump is met, the design structure is compact, and the overall structural design is optimized on the premise that the design target is achieved.

Description

Technical Field

[0001] This invention relates to the field of axial piston pump technology, specifically to a transmission structure between the shaft and cylinder of an axial piston pump. Background Technology

[0002] Hydraulic transmission technology, with its core advantages of high power density, smooth transmission, and precise control, occupies an irreplaceable position in modern industry, especially in the construction machinery industry, where it serves as the core power transmission hub. From the bucket operation of excavators and the boom lifting of cranes to the loading and pushing of loaders, the key actions of various construction machinery rely on hydraulic transmission systems to achieve power conversion and transmission. The performance of hydraulic pumps directly determines the overall operating efficiency and reliability of the machine. Among them, swashplate axial piston pumps, due to their wide displacement adjustment range, strong stability under high pressure conditions, and excellent power-to-weight ratio, have become the preferred pump type for hydraulic systems of mainstream construction machinery such as excavators, concrete pump trucks, and crawler cranes, widely undertaking the key mission of core power output.

[0003] Modern axial piston pumps can be mainly divided into swashplate axial piston pumps and swashplate-shaft axial piston pumps according to their structural form. The intersection angle between the central axis of the input shaft and the central axis of the rotary cylinder of the swashplate-shaft axial piston pump is between 35° and 45°. The input shaft of the swashplate axial piston pump transmits the rotational speed and power to the rotary cylinder through a transmission hinge, disc gear, and universal joint. Although the transmission structure of the transmission hinge and universal joint can change the intersection angle, in use, the power source first drives the transmission shaft to rotate the cylinder. The piston moves in a reciprocating linear motion along the piston hole of the cylinder under the action of the return plate and the swashplate. The rotating cylinder cooperates with the fixed distribution plate to realize the oil suction and oil pressure process. Finally, the piston stroke can be changed by adjusting the swashplate tilt angle through a variable mechanism, thereby realizing flexible control of the pump displacement and output flow.

[0004] The structural characteristics of swashplate axial piston pumps dictate that there is a 35° to 45° intersection angle between the input shaft and the central axis of the rotary cylinder. While this angle ensures the stroke requirements of the piston's reciprocating motion, it also becomes the main source of mechanical load. The larger the intersection angle, the greater the radial force, axial thrust, and additional bending moment the input shaft will simultaneously bear. To avoid shaft bending or fatigue fracture, the input shaft diameter needs to be increased to improve rigidity. At the same time, larger loads require matching with larger bearings with stronger load-bearing capacity. The increase in bearing specifications and shaft size forces the pump body casting housing to expand the internal installation space for the same pressure rating. Ultimately, this leads to an increase in the pump's rotor inertia and a surge in overall volume, which not only increases the installation space requirements but also restricts the overall lightweight design of the machine. Summary of the Invention

[0005] Based on the aforementioned problems in the existing technology, the problem to be solved by this application is that: the larger the fork angle, the greater the radial force, axial thrust and additional torque that the input shaft will bear at the same time. In order to avoid shaft bending or fatigue fracture, the input shaft diameter needs to be increased in the design to improve rigidity. At the same time, the larger load requires matching with larger bearings with stronger load-bearing capacity. However, the increase in bearing specifications and shaft size forces the pump body casting housing under the same pressure level to expand the internal installation space, which ultimately leads to an increase in the pump rotor inertia and a surge in the overall volume. This not only increases the installation space requirement, but also restricts the lightweight design of the whole machine.

[0006] The technical solution adopted by this application to solve its technical problem is: a transmission structure between the shaft and cylinder of an axial piston pump, including an input shaft and a limiting plate, wherein the input shaft and the limiting plate are rotatably connected. A connecting unit includes a rotary cylinder movably disposed on the outer circumferential surface of the input shaft, a connector fixedly disposed on the input shaft, a pin slidably disposed on the outer circumferential surface of the connector, and a plurality of pins evenly distributed among them; a guide groove is provided on the inner wall of the rotary cylinder, and the connector and the connecting shaft are mutually matched. The transmission unit includes a distribution plate fixedly mounted on the input shaft, the distribution plate being in contact with the rotary cylinder body, the distribution plate having a feeding groove, the rotary cylinder body having a cylinder groove, the bottom end of the cylinder groove having a feed inlet, and the width of the feeding groove being not less than the width of the feed inlet, the cylinder groove having a guide groove slidably disposed therein, the limiting plate having a limiting groove, and the guide groove and the limiting groove being slidably connected.

[0007] Preferably, anti-slip ribs are fixedly provided on both ends of the input shaft, the rotary cylinder is inclined to the input shaft, the limiting plate is perpendicular to the input shaft, and the rotary cylinder and the limiting plate are coaxial.

[0008] Preferably, a sliding plate is slidably disposed in the cylinder groove, the sliding plate is fixedly connected to the connecting shaft, and a retaining ball is fixedly disposed on both ends of the connecting shaft. A fixing groove is provided on the sliding plate, and the retaining ball and the fixing groove are matched with each other. Furthermore, the connecting shafts on the rotary cylinder are arranged parallel to each other.

[0009] Preferably, a second sliding groove is provided on one side of the input shaft, and a first sliding groove is provided on the other side of the input shaft. A positioning plate is slidably disposed on the second sliding groove, and an airbag is fixedly disposed on the positioning plate. A buffer rod is slidably disposed on the input shaft, and a telescopic device is fixedly disposed inside the input shaft. The buffer rod and the telescopic device are slidably connected, and the telescopic device and the airbag are interconnected.

[0010] Preferably, a shaft body is slidably disposed on the pin, a spring is fixedly disposed on one end of the shaft body, the spring is fixedly connected to the input shaft, a groove is formed on the outer circumferential surface of the shaft body, and a locking slot is formed at the connection between the shaft body and the pin.

[0011] Preferably, a sliding plate is slidably disposed on the slide groove, and the sliding plate is fixedly connected to the shaft.

[0012] Preferably, a gear is rotatably mounted inside the input shaft, a toothed plate is fixedly mounted on the slide plate, a toothed plate is fixedly mounted on the positioning plate, and the toothed plate and the toothed plate are uniformly meshed with each other between the gears, and the input shaft is provided with a slack groove.

[0013] Preferably, a positioning hole is provided on the outer peripheral surface of the input shaft, the buffer rod is slidably disposed in the positioning hole, and a ball is fixedly disposed on the end of the buffer rod, the ball being in contact with the inner wall of the limiting plate.

[0014] Preferably, the depth of the cylinder groove is greater than the length of the connecting shaft, and the length of the connecting shaft is not less than the distance between the rotary cylinder and the limiting plate.

[0015] Preferably, the length of the toothed plate is not greater than the depth of the hysteresis groove.

[0016] The beneficial effects of this application are as follows: This invention provides a novel transmission structure for the shaft and cylinder of an axial piston pump, achieving the characteristics of simple mechanism, fewer parts, convenient manufacturing and assembly, reduced size, and good durability. Furthermore, the unevenness of speed conversion is reduced in both low-speed and high-speed operation. The torque transmission capacity is not reduced due to increased wear clearance between the flexible pin and the rotary cylinder, thus satisfying the good dynamic performance of the hydraulic pump. The transmission mechanism of this axial piston pump has a compact design. While achieving the design objectives, the overall structural design is optimized, reducing the axial and radial distances of the transmission mechanism. A connector machined on the input shaft and a cylindrical surface machined on the rotary cylinder form a linear height pair for spatial motion. Five shafts and pins machined on the outer circumference of the connector form a cylindrical pair for spatial motion. Similarly, five connecting shafts and pins machined on the circumference of the rotary cylinder form a linear height pair for spatial motion. The rotary cylinder and the distribution plate form a planar pair for spatial motion, and the input shaft and the limiting plate form a planar transmission pair. This is the transmission mechanism between the shaft and cylinder. Attached Figure Description

[0017] Figure 1 This is a three-dimensional structural diagram of the present invention; Figure 2 This is a side view of the structure of the present invention; Figure 3 This is a schematic diagram of the internal structure of the rotary cylinder of the present invention; Figure 4 This is a schematic diagram of the drawer structure of the present invention; Figure 5 This is a schematic diagram of the input shaft structure of the present invention; Figure 6 This is a schematic diagram of the internal structure of the input shaft of the present invention; Figure 7 For the present invention Figure 6 Enlarged structural diagram at point A in the middle; Figure 8 This is a schematic diagram of the pin structure of the present invention.

[0018] In the diagram: 1. Input shaft; 11. Anti-slip ridge; 12. Positioning hole; 13. Slide groove one; 2. Limiting plate; 21. Limiting groove; 3. Rotary cylinder body; 31. Cylinder groove; 32. Pulling plate; 321. Fixing groove; 33. Connecting shaft; 34. Guide groove; 331. Ball clamp; 4. Distribution plate; 41. Feeding groove; 5. Buffer rod; 51. Ball; 52. Telescopic device; 53. Airbag; 54. Positioning plate; 6. Pin shaft; 60. Connector; 61. Shaft body; 611. Slide plate; 612. Gear plate one; 613. Retention groove; 62. Slot; 63. Spring; 64. Bayonet; 7. Slide groove two; 8. Gear; 9. Gear plate two. Detailed Implementation

[0019] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0020] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0021] Reference Figures 1-8 A transmission structure between the shaft and cylinder of an axial piston pump includes an input shaft 1 and a limiting plate 2, wherein the input shaft 1 and the limiting plate 2 are rotatably connected. The connecting unit includes a rotary cylinder 3 movably disposed on the outer peripheral surface of the input shaft 1, a connector 60 fixedly disposed on the input shaft 1, a pin 6 slidably disposed on the outer peripheral surface of the connector 60, and multiple pins 6 evenly distributed among them, and a guide groove 34 is provided on the inner wall of the rotary cylinder 3, and the connector 60 and the guide groove 34 are matched with each other. The transmission unit includes a distribution plate 4 fixedly mounted on the input shaft 1. The distribution plate 4 and the rotary cylinder 3 are in close contact with each other. The distribution plate 4 has a feeding groove 41, and the rotary cylinder 3 has a cylinder groove 31. The bottom end of the cylinder groove 31 has a feed inlet, and the width of the feeding groove 41 is not less than the width of the feed inlet. A connecting shaft 33 is slidably mounted in the cylinder groove 31. A limit groove 21 is provided on the limiting plate 2, and the connecting shaft 33 and the limit groove 21 are slidably connected.

[0022] Reference Figures 1-5 Anti-slip ribs 11 are fixedly provided on both ends of the input shaft 1. The rotary cylinder 3 is inclined to the input shaft 1. The limiting plate 2 is perpendicular to the input shaft 1. The rotary cylinder 3 and the limiting plate 2 are coaxial. The anti-slip ribs 11 on the outer circumference of the input shaft 1 facilitate the connection of the device by the operator and make it easy to pick up during assembly. At the same time, the inclined rotary cylinder 3 enables the connecting shaft 33 in the cylinder groove 31 and the external limiting plate 2 to operate when the input shaft 1 rotates.

[0023] Reference Figure 1 - Figure 4 A drawer plate 32 is slidably disposed in the cylinder groove 31. The drawer plate 32 is fixedly connected to the connecting shaft 33. The left and right ends of the connecting shaft 33 are fixedly disposed with retaining balls 331. A fixing groove 321 is provided on the drawer plate 32. The retaining balls 331 and the fixing groove 321 are matched with each other. The connecting shafts 33 on the rotary cylinder body 3 are arranged parallel to each other. By using the drawer plate 32 disposed in the cylinder groove 31, the rotary cylinder body 3 rotates along with the input shaft 1 during rotation. When the drawer plate 32 at the farthest end of the rotary cylinder body 3 from the limiting plate 2 begins to move, the distance between the drawer plate 32 and the limiting plate 2 gradually decreases. At this time, the drawer plate 32 will draw material from the feeding groove 41 and fill it into the cylinder groove 31. When the drawer plate 32 starts to move from the closest end, the drawer plate 32 will compress the material in the cylinder groove 31.

[0024] Reference Figures 3-7 A second slide groove 7 is provided on one side of the input shaft 1, and a first slide groove 13 is provided on the other side of the input shaft 1. A positioning plate 54 is slidably mounted on the second slide groove 7, and an airbag 53 is fixedly mounted on the positioning plate 54. A buffer rod 5 is slidably mounted on the input shaft 1, and a telescopic device 52 is fixedly mounted inside the input shaft 1. The buffer rod 5 and the telescopic device 52 are slidably connected, and the telescopic device 52 and the airbag 53 are interconnected. The second slide groove 7 in the input shaft 1 limits the positioning plate 54, ensuring that it can move within the second slide groove 7, and compresses the airbag 53 during its movement, so that it can push the buffer rod 5 on the input shaft 1 to move.

[0025] Reference Figures 2-7A shaft body 61 is interactively arranged on the pin 6. A spring 63 is fixedly arranged on one end of the shaft body 61. The spring 63 is fixedly connected to the input shaft 1. A slot 62 is opened on the outer circumference of the shaft body 61. A slot 64 is opened at the connection between the shaft body 61 and the pin 6. The shaft body 61 arranged on the pin 6 can be used to connect the input shaft 1 and the rotary cylinder 3. The pin 6 can be locked in the guide groove 34.

[0026] Reference Figures 5-8 A slide plate 611 is slidably mounted on the slide groove 13. The slide plate 611 is fixedly connected to the shaft 61. The slide plate 611 is mounted on the slide groove 13 so that the shaft 61 can move synchronously during the movement of the slide plate 61.

[0027] Reference Figures 5-8 A gear 8 is rotatably mounted inside the input shaft 1. A toothed plate 612 is fixedly mounted on the slide plate 611, and a toothed plate 9 is fixedly mounted on the positioning disk 54. The toothed plate 612 and the toothed plate 9 are uniformly meshed with the gear 8. The input shaft 1 has a slack groove 613. The gear 8 mounted on the input shaft 1 enables the toothed plate 612 to rotate as the shaft 61 moves the slide plate 611. The rotating gear 8 can drive the toothed plate 9 to move. This means that when the angle between the input shaft 1 and the rotary cylinder 3 increases, the displacement distance of the toothed plate 612 increases. At this time, the pressure on the airbag 53 will increase, and the buffer rod 5 will stick to the inner wall of the limiting disk 2 to ensure the stability of the device during operation.

[0028] Reference Figures 4-8 A positioning hole 12 is provided on the outer circumferential surface of the input shaft 1. The buffer rod 5 is slidably disposed in the positioning hole 12. A ball 51 is fixedly disposed at the end of the buffer rod 5. The ball 51 is in contact with the inner wall of the limiting plate 2. The positioning hole 12 on the input shaft 1 ensures the stability of the buffer rod 5 when it moves.

[0029] Reference Figures 4-8 The depth of the cylinder groove 31 is greater than the length of the connecting shaft 33, the length of the connecting shaft 33 is not less than the distance between the rotary cylinder 3 and the limit plate 2, and the length of the toothed plate 612 is not greater than the depth of the stagnation groove 613. By setting the size relationship between each component, the device can be made to operate stably and jamming can be avoided.

[0030] The specific solution is as follows: When using the device, the operator first fixes the device in the predetermined position, and fixes the limiting plate 2 in the external cavity. The anti-slip rib 11 set on the outer circumference of the input shaft 1 facilitates the operator's connection of the device and makes it easy to handle during assembly. At the same time, the tilted rotary cylinder 3 enables the connecting shaft 33 in the cylinder groove 31 and the external limiting plate 2 to operate when the input shaft 1 rotates. When the input shaft 1 rotates, the drawer 32 set in the cylinder groove 31 enables the rotary cylinder 3 to rotate along with the input shaft 1. When the drawer 32 at the farthest end of the rotary cylinder 3 from the limiting plate 2 begins to move, the distance between the drawer 32 and the limiting plate 2 gradually decreases. At this time, the drawer 32 will draw material from the feeding tank 41 and fill it into the cylinder groove 31. When the drawer 32 starts to move from the closest end, the drawer 32 will compress the cylinder. The material in the groove 31, and when the angle between the input shaft 1 and the rotary cylinder 3 is too large, the shaft 61 will move under the action of the spring 63. During the movement of the shaft 61, it can drive the slide plate 611 to move synchronously. When the shaft 61 drives the slide plate 611 to move, the toothed plate 612 moves accordingly. The toothed plate 612 can drive the gear 8 to rotate. The rotating gear 8 can drive the toothed plate 9 to move. When the angle between the input shaft 1 and the rotary cylinder 3 increases, the displacement distance of the toothed plate 612 is greater. At this time, the pressure on the airbag 53 will increase, and the buffer rod 5 will stick to the inner wall of the limiting plate 2 to ensure the stability of the device during operation. As the toothed plate 9 moves, the positioning plate 54 moves in the slide groove 7, and during its movement, it can compress the airbag 53, so that it can push the buffer rod 5 on the input shaft 1 to move, ensuring the stability of the device.

[0031] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary. Under the framework of this invention, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of the different aspects of the invention as described above, which are not provided in detail for the sake of brevity.

[0032] This invention is intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A transmission structure between the shaft and cylinder of an axial piston pump, comprising an input shaft (1) and a limiting disc (2), wherein the input shaft (1) and the limiting disc (2) are rotatably connected, characterized in that... Also includes: The connecting unit includes a rotary cylinder (3) movably disposed on the outer circumferential surface of the input shaft (1), a connector (60) fixedly disposed on the input shaft (1), a pin (6) slidably disposed on the outer circumferential surface of the connector (60), and a plurality of pins (6) evenly arranged among each other, a guide groove (34) is provided on the inner wall of the rotary cylinder (3), and the connector (60) and the guide groove (34) are matched with each other; The transmission unit includes a distribution plate (4) fixedly mounted on the input shaft (1), the distribution plate (4) and the rotary cylinder (3) being in close contact with each other, the distribution plate (4) having a feeding groove (41), the rotary cylinder (3) having a cylinder groove (31), the bottom end of the cylinder groove (31) having a feed inlet, and the width of the feeding groove (41) being not less than the width of the feed inlet, a connecting shaft (33) being slidably mounted in the cylinder groove (31), a limiting groove (21) being opened on the limiting plate (2), and the connecting shaft (33) being slidably connected to the limiting groove (21).

2. The transmission structure between the shaft and cylinder of an axial piston pump according to claim 1, characterized in that, Both ends of the input shaft (1) are fixedly provided with anti-slip ribs (11), the rotary cylinder (3) is inclined to the input shaft (1), the limiting plate (2) is perpendicular to the input shaft (1), and the rotary cylinder (3) is coaxial with the limiting plate (2).

3. The transmission structure between the shaft and cylinder of an axial piston pump according to claim 1, characterized in that, A sliding plate (32) is slidably disposed in the cylinder groove (31). The sliding plate (32) is fixedly connected to the connecting shaft (33). A retaining ball (331) is fixedly disposed on the left and right ends of the connecting shaft (33). A fixing groove (321) is provided on the sliding plate (32). The retaining ball (331) and the fixing groove (321) are matched with each other. The connecting shafts (33) on the rotary cylinder (3) are arranged parallel to each other.

4. The transmission structure between the shaft and cylinder of an axial piston pump according to claim 1, characterized in that, A second groove (7) is provided on one side of the input shaft (1), and a first groove (13) is provided on the other side of the input shaft (1). A positioning plate (54) is slidably arranged on the second groove (7), and an airbag (53) is fixedly arranged on the positioning plate (54). A buffer rod (5) is slidably arranged on the input shaft (1), and a telescopic device (52) is fixedly arranged inside the input shaft (1). The buffer rod (5) and the telescopic device (52) are slidably connected, and the telescopic device (52) and the airbag (53) are interconnected.

5. The transmission structure between the shaft and cylinder of an axial piston pump according to claim 4, characterized in that, A shaft (61) is slidably disposed on the pin (6), and a spring (63) is fixedly disposed on one end of the shaft (61). The spring (63) is fixedly connected to the input shaft (1). A slot (62) is provided on the outer circumferential surface of the shaft (61), and a bayonet (64) is provided at the connection between the shaft (61) and the pin (6).

6. The transmission structure between the shaft and cylinder of an axial piston pump according to claim 5, characterized in that, A slide plate (611) is slidably disposed on the slide groove (13), and the slide plate (611) is fixedly connected to the shaft (61).

7. The transmission structure between the shaft and cylinder of an axial piston pump according to claim 6, characterized in that, The input shaft (1) is rotatably provided with a gear (8), the slide plate (611) is fixedly provided with a toothed plate (612), the positioning plate (54) is fixedly provided with a toothed plate (9), and the toothed plate (612) and the toothed plate (9) are evenly meshed with each other between the gear (8), and the input shaft (1) is provided with a slack groove (613).

8. The transmission structure between the shaft and cylinder of an axial piston pump according to claim 4, characterized in that, A positioning hole (12) is provided on the outer peripheral surface of the input shaft (1). The buffer rod (5) is slidably disposed in the positioning hole (12). A ball (51) is fixedly disposed on the end of the buffer rod (5). The ball (51) is in contact with the inner wall of the limiting plate (2).

9. The transmission structure between the shaft and cylinder of an axial piston pump according to claim 1, characterized in that, The depth of the cylinder groove (31) is greater than the length of the connecting shaft (33), and the length of the connecting shaft (33) is not less than the distance between the rotary cylinder (3) and the limiting plate (2).

10. The transmission structure between the shaft and cylinder of an axial piston pump according to claim 7, characterized in that, The length of the toothed plate (612) is not greater than the depth of the stabilizing groove (613).

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