An anti-eccentric load static pressure support sleeve and an anti-eccentric load servo cylinder using the support sleeve

Abstract

The present invention relates to the technical field of heavy-duty servo hydraulic cylinder design, specifically to an anti-eccentric load hydrostatic support sleeve and an anti-eccentric load servo cylinder using the support sleeve. The hydrostatic support sleeve is composed of an outer sleeve with an arc-shaped groove and an inner sleeve with an arc-shaped boss. When the servo cylinder is subjected to a lateral force, the hydrostatic support inner sleeve can achieve a certain angle of deflection around the axis of its arc-shaped boss. The hydrostatic support inner sleeve decomposes part of the lateral force to the cylinder barrel by achieving a small deflection around the axis, effectively reducing the force on the hydrostatic support oil film and preventing the oil film from being damaged and causing eccentric wear of the piston rod. In order to prevent the inner sleeve and the outer sleeve from getting stuck when they rotate relative to each other, a plurality of arc-shaped pressure-equalizing grooves are provided on the arc-shaped outer surface of the hydrostatic support inner sleeve. When the servo cylinder is subjected to a lateral force, the oil film between the inner and outer sleeves is squeezed and thinned under the action of the external load, and the oil is squeezed out of the gap to form an extrusion effect, which can effectively improve the anti-eccentric load capability of the hydrostatic support inner sleeve.

Description

Technical Field

[0001] The invention relates to the technical field of heavy-load servo hydraulic cylinder design, in particular to an anti-eccentric load static pressure support sleeve and an anti-eccentric load servo cylinder using the support sleeve. Background Art

[0002] In recent years, with the increasing demand for intelligent equipment in my country's market, the technology of high-frequency heavy-duty servo cylinders, as important hydraulic actuators for intelligent equipment, has also made great progress. However, there is currently a technical bottleneck in high-frequency heavy-duty hydraulic cylinders. When the servo cylinder is subjected to lateral force loading, the lateral force of the servo cylinder with the current hydrostatic support structure is borne by the oil film within the hydrostatic support. This destroys the oil film support and causes eccentric wear of the piston rod and cylinder barrel, seriously affecting the service life of the servo cylinder. Therefore, it is necessary to design a new type of servo cylinder anti-eccentric load hydrostatic support structure to improve the adverse stress conditions of the hydrostatic support under heavy and eccentric loads, and effectively improve the reliability of the servo cylinder. Summary of the Invention

[0003] The present invention aims to solve the technical problem that when a servo cylinder is subjected to lateral force loading, the lateral force is borne by the oil film in the hydrostatic support, which easily damages the oil film support and causes eccentric wear of the piston rod and cylinder barrel, seriously affecting the service life of the servo cylinder. The present invention provides an anti-eccentric load hydrostatic support sleeve and an anti-eccentric load servo cylinder using the support sleeve.

[0004] The present invention is implemented by adopting the following technical scheme: an anti-eccentric load static pressure support sleeve, comprising an outer sleeve with an arc-shaped groove and an inner sleeve with an arc-shaped convex groove; the outer diameter of the outer sleeve remains unchanged, and the inner diameter gradually increases from the middle to the two ends, forming an arc-shaped groove; the inner diameter of the inner sleeve remains unchanged, and the outer diameter gradually decreases from the middle to the two ends, forming an arc-shaped convex groove; the inner sleeve is installed inside the outer sleeve and the two are gap-sealed; the outer sleeve and the inner sleeve are both provided with a high-pressure oil inlet and a low-pressure oil drain required for static pressure support.

[0005] When in use, the present invention is placed around the outside of the circumference of the servo cylinder's piston rod. High-pressure oil flows through the high-pressure oil inlet on the outer sleeve, entering between the inner and outer sleeves and forming an oil film. Simultaneously, it enters the high-pressure oil inlet on the inner sleeve, entering the inner sleeve and forming an oil film between the inner sleeve and the piston rod, thus providing a hydrostatic support. When the servo cylinder is subjected to lateral forces, the hydrostatic support inner sleeve deflects a certain angle about the axis of its curved boss, distributing a portion of the lateral force to the cylinder barrel. This effectively reduces the stress on the hydrostatic support oil film and prevents damage to the oil film and eccentric wear of the piston rod.

[0006] Furthermore, a plurality of arc-shaped pressure-equalizing grooves are opened on the outer wall of the inner sleeve, distributed on both sides of the high-pressure oil inlet and the low-pressure oil drain, and arranged in a wave-like manner around the outer wall of the inner sleeve.

[0007] In order to prevent the inner sleeve and the outer sleeve from getting stuck when they rotate relative to each other, a plurality of arc-shaped pressure equalizing grooves are opened on the arc-shaped outer surface of the inner sleeve of the hydrostatic support. At the same time, when the hydraulic cylinder is subjected to lateral force, the oil film between the inner and outer sleeves is squeezed and thinned under the action of the external load, and the oil is squeezed out of the gap to form an extrusion effect. Since the force-bearing area of the arc-shaped pressure equalizing groove is larger than that of the circular pressure equalizing groove, the radial force generated is also larger, thereby effectively improving the anti-eccentric load capacity of the inner sleeve of the hydrostatic support.

[0008] The anti-eccentric load servo cylinder described in the present invention adopts the following technical solution: the servo cylinder includes a cylinder barrel and a piston rod; the piston rod is provided with a group of anti-eccentric load static pressure support sleeves at both ends located in the cylinder barrel; the outer sleeve of the anti-eccentric load static pressure support sleeve corresponds to the high-pressure oil inlet / low-pressure oil drain port of the inner sleeve one by one; each anti-eccentric load static pressure support sleeve is provided with a cylinder cover that is sleeved on the piston rod and fixedly connected to the end face of the cylinder barrel on the axially outward part, and the inner wall of the inner sleeve near its two ends is provided with a sealing groove, and the sealing groove is installed with a sealing member to achieve sealing between the piston rod; the cylinder barrel is provided with a high-pressure oil inlet and a low-pressure oil drain port corresponding to the outer sleeve.

[0009] The anti-eccentric load servo cylinder of the present invention features an ingeniously designed anti-eccentric load hydrostatic support sleeve structure. By utilizing an outer sleeve with an arcuate groove and an inner sleeve with an arcuate convex groove, the inner sleeve can deflect a certain angle about the axis of its arcuate boss, partially distributing lateral forces to the cylinder barrel. This effectively reduces the stress on the hydrostatic support oil film and prevents eccentric wear of the piston rod caused by oil film damage. The present invention has a simple structure, low manufacturing cost, and excellent performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 Schematic diagram of the servo cylinder structure with an anti-eccentric load hydrostatic support sleeve.

[0011] Figure 2 Schematic diagram of the inner sleeve structure with arc-shaped boss.

[0012] Figure 3 Schematic diagram of the jacket structure with arc-shaped grooves.

[0013] Figure 4 Schematic diagram of the circular pressure-equalizing groove on the outer surface of the inner sleeve and its structure. 1-Outer sleeve, 2-Inner sleeve, 3-Piston rod, 4-Cylinder barrel, 5-Cylinder head, 6-Screw, 7-Seal, 8-Left outer sleeve, 9-Right outer sleeve, 10-Pin, 11-Circular pressure-equalizing groove, 12-Throttle, 13-Connecting lug, 14-Circular pressure-equalizing groove. DETAILED DESCRIPTION

[0014] Example 1

[0015] An anti-eccentric load static pressure support sleeve comprises an outer sleeve 1 with an arcuate groove and an inner sleeve 2 with an arcuate convex groove. The outer sleeve 1 has a constant outer diameter, while its inner diameter gradually increases from the middle to the ends, forming the arcuate groove. The inner sleeve 2 has a constant inner diameter, while its outer diameter gradually decreases from the middle to the ends, forming the arcuate convex groove. The inner sleeve 2 is mounted within the outer sleeve 1, with a gap and a seal between the two. Both the outer sleeve 1 and the inner sleeve 2 are provided with the high-pressure oil inlet and low-pressure oil drain required for static pressure support. The outer wall of the inner sleeve 2 is provided with multiple arcuate pressure-equalizing grooves 11, distributed on both sides of the high-pressure oil inlet and low-pressure oil drain, and arranged in a wave-like pattern around the outer wall of the inner sleeve 2.

[0016] Example 2

[0017] A throttle 12 is also installed in the high-pressure oil inlet on the inner sleeve 2; the high-pressure oil enters between the inner and outer sleeves through the high-pressure oil inlet on the outer sleeve 1 and forms an oil film, and at the same time enters the high-pressure oil inlet on the inner sleeve 2, passes through the throttle port on the throttle 12, enters the inner sleeve 2 and forms an oil film between the inner sleeve 2 and the piston rod 3, and the internal leakage of the oil film flows out from the low-pressure oil drain port; the static pressure support changes the flow rate through the throttle port on the throttle 12 to compensate for the change in load on the static pressure support to maintain the stability of its oil film.

[0018] Example 3

[0019] The outer sleeve 1 and the inner sleeve 2 are sealed by grinding. The outer sleeve 1 is formed by connecting a left half outer sleeve 8 and a right half outer sleeve 9, and the two are connected by a pin 10.

[0020] Example 4

[0021] A servo cylinder with an anti-eccentric load, comprising a cylinder barrel 4 and a piston rod 3; the piston rod 3 is provided with a set of anti-eccentric load static pressure support sleeves at both ends located in the cylinder barrel 4; the outer sleeve 1 of the anti-eccentric load static pressure support sleeve corresponds to the high-pressure oil inlet / low-pressure oil drain port of the inner sleeve 2; a cylinder head 5 is provided on the axially outward portion of each anti-eccentric load static pressure support sleeve, which is sleeved on the piston rod 3 and fixedly connected to the end face of the cylinder barrel 4; the inner wall of the inner sleeve 2 is provided with a sealing groove near its two ends, and the sealing groove is equipped with a seal 7 for sealing with the piston rod 3; the cylinder barrel 4 is provided with a high-pressure oil inlet and a low-pressure oil drain port corresponding to the outer sleeve 1. A seal is also fixedly provided on the inner wall of the cylinder head 5; the cylinder head 5 and the cylinder barrel are connected by screws 7. The two ends of the piston rod 3 extend out of the cylinder barrel and are respectively connected to a connecting ear seat 13 through threads.

[0022] The technical features of the above-mentioned anti-eccentric load servo cylinder are as follows: 1. The hydrostatic support sleeve is composed of an outer sleeve with an arc-shaped groove and an inner sleeve with an arc-shaped boss. When the servo cylinder is subjected to lateral force, the hydrostatic support inner sleeve can achieve a certain angle of deflection around the axis of its arc-shaped boss.

[0023] 2. The inner sleeve of the hydrostatic bearing decomposes part of the lateral force onto the cylinder barrel by achieving a small deflection around the axis, effectively reducing the force on the hydrostatic bearing oil film and preventing the oil film from being damaged and causing eccentric wear of the piston rod.

[0024] 3. In order to prevent the inner sleeve and the outer sleeve from getting stuck when they rotate relative to each other, a number of arc-shaped pressure-equalizing grooves are opened on the arc-shaped outer surface of the inner sleeve of the hydrostatic support. At the same time, when the servo cylinder is subjected to lateral force, the oil film between the inner and outer sleeves is squeezed and thinned under the action of the external load, and the oil is squeezed out of the gap to form an extrusion effect. Because the force area of the arc-shaped pressure-equalizing groove is larger than that of the circular pressure-equalizing groove, the radial force generated is also larger, which can effectively improve the anti-eccentric load capacity of the inner sleeve of the hydrostatic support.

[0025] The present invention is further described below with reference to the embodiments and accompanying drawings.

[0026] like Figure 1 、 Figure 2 、 Figure 3 As shown: The anti-eccentric load static pressure support sleeve consists of an outer sleeve 1 with an arc-shaped groove and an inner sleeve 2 with an arc-shaped convex groove. The inner sleeve 2 is installed inside the outer sleeve 1, and the gap sealing is achieved through matching and grinding. The inner sleeve 2 and the outer sleeve 1 are installed together between the piston rod 3 and the cylinder barrel 4, and are axially fixed to the cylinder barrel 4 by the cylinder cover 5 through the screw 6. There are seals 7 between the outer sleeve 1, the inner sleeve 2 and the cylinder cover 5 to prevent the oil cylinder from leaking. The static pressure support inner sleeve 2 can achieve a certain angle of deflection around its arc axis. In order to ensure assembly requirements, the outer sleeve 2 is composed of a left half outer sleeve 8 and a right half outer sleeve 9. The left half outer sleeve 8 and the right half outer sleeve 9 are tightly connected together by a pin 10 in the middle.

[0027] like Figure 4 As shown on the left, to prevent the inner sleeve 2 from getting stuck when the outer sleeve 1 deflects relative to the inner sleeve 2, multiple circular arc-shaped pressure-equalizing grooves 11 are opened on the surface of the inner sleeve 2, between the high- and low-pressure chambers and on both sides. At the same time, when the servo cylinder is subjected to lateral force, the oil film between the inner and outer sleeves is squeezed and thinned under the action of the external load, and the oil is squeezed out of the gap, forming a squeezing effect. Because the force-bearing area of the circular arc-shaped pressure-equalizing groove 11 is larger than that of the circular annular groove, the radial force generated is also greater, effectively improving the anti-eccentric load capacity of the static pressure bearing inner sleeve 2. The right side of the figure shows a schematic diagram of a traditional circular pressure-equalizing groove.

[0028] When the hydrostatic support inner sleeve 2 is subjected to a radial lateral force, it deflects a certain angle about its axis. During this deflection, the vertical radial force itself is absorbed by the oil film within the hydrostatic support inner sleeve 2. With the anti-eccentric load hydrostatic support inner sleeve 2, the hydrostatic support inner sleeve 2 achieves a small deflection about its axis, which partially deflects the lateral force onto the cylinder 4, effectively reducing the stress on the hydrostatic support oil film.

Claims

1. An anti-eccentric load static pressure support sleeve, characterized in that: The invention comprises an outer sleeve (1) with an arc-shaped groove and an inner sleeve (2) with an arc-shaped convex groove; the outer sleeve (1) has a constant outer diameter, and the inner diameter gradually decreases from the middle to the two ends, forming an arc-shaped groove; the inner sleeve (2) has a constant inner diameter, and the outer diameter gradually decreases from the middle to the two ends, forming an arc-shaped convex groove; the inner sleeve (2) is installed inside the outer sleeve (1) and the two are gap-sealed; the outer sleeve (1) and the inner sleeve (2) are both provided with a high-pressure oil inlet and a low-pressure oil drain required for static pressure support; a plurality of arc-shaped equalizing pressure grooves (11) are provided on the outer wall of the inner sleeve (2), distributed on both sides of the high-pressure oil inlet and the low-pressure oil drain, and arranged in a wave-like manner around the outer wall of the inner sleeve (2); a gap seal is achieved between the outer sleeve (1) and the inner sleeve (2) by matching; the inner sleeve (2) can achieve a certain angle of deflection around its axis.

2. The anti-eccentric load static pressure support sleeve according to claim 1, characterized in that: A throttle (12) is also installed in the high-pressure oil inlet on the inner sleeve (2); the high-pressure oil enters between the inner and outer sleeves through the high-pressure oil inlet on the outer sleeve (1) and forms an oil film, and at the same time enters the high-pressure oil inlet on the inner sleeve (2), passes through the throttle on the throttle (12), enters the inner sleeve (2) and forms an oil film between the inner sleeve (2) and the piston rod (3), and the internal leakage of the oil film flows out from the low-pressure oil drain port; the static pressure support changes the flow rate through the throttle on the throttle (12) to compensate for the change in the load on the static pressure support, so as to maintain the stability of its oil film.

3. The anti-eccentric load static pressure support sleeve according to claim 1 or 2, characterized in that: The outer jacket (1) is formed by butting a left half outer jacket (8) and a right half outer jacket (9), which are connected via a pin (10).

4. An anti-eccentric load servo cylinder, comprising a cylinder barrel (4) and a piston rod (3); characterized in that: The piston rod (3) is provided with a set of anti-eccentric load static pressure support sleeves as described in any one of claims 1 to 3 at both ends of the piston rod (3) located in the cylinder (4); the outer sleeve (1) of the anti-eccentric load static pressure support sleeve corresponds to the high-pressure oil inlet / low-pressure oil drain port of the inner sleeve (2) one by one; each anti-eccentric load static pressure support sleeve is provided with a cylinder head (5) which is sleeved on the piston rod (3) and fixedly connected to the end face of the cylinder (4) along the axial outward portion, and the inner sleeve (2) is provided with a sealing groove on the inner wall near its two ends, and a sealing member (7) is installed in the sealing groove to achieve sealing between the piston rod (3); the cylinder (4) is provided with a high-pressure oil inlet and a low-pressure oil drain port corresponding to the outer sleeve (1); when the servo cylinder is subjected to lateral force, the inner sleeve (2) can achieve a certain angle of deflection around its axis.

5. The anti-eccentric load servo cylinder according to claim 4, characterized in that: The cylinder cover (5) and the cylinder barrel (4) are connected via screws (6).

6. The anti-eccentric load servo cylinder according to claim 4 or 5, characterized in that: Both ends of the piston rod (3) extend out of the cylinder barrel (4) and are respectively connected to a connecting ear seat (13) through a thread.

Images