CN109296592B - Piston assembly for high-pressure low-friction hydraulic cylinder - Google Patents

Abstract

The present invention relates to a piston assembly for a high pressure, low friction hydraulic cylinder. The technical solution is: the piston assembly is composed of a support ring (1), a sealing ring assembly (2), a sealing ring (3) and a piston (4). There is a sealing groove (6) at the center of the two support ring grooves (5) of the piston (4). A sealing ring (3) is installed at the bottom of the sealing groove (6), and is set close to the outer wall of the sealing ring (3). There are sealing ring components (2). The sealing ring assembly (2) is a complete annular shape composed of a sealing ring (7) and a rubber gasket (8). The outer wall of the sealing ring (7) is evenly provided with large blind holes, and the large blind holes are located in the sealing ring (7). ), passing through the center of the large blind hole and having 2 small blind holes in directions of positive 45° and negative 45° to the center line of the sealing ring (7); the sealing ring (3) is a circular ring. Open style. The invention has the characteristics of small friction, high frequency response, ability to withstand high pressure, good sealing performance, long working life, automatic adjustment of the sealing gap and convenient disassembly and assembly, and is suitable for high-pressure and low-friction hydraulic cylinders.

Description

A piston assembly for a high-pressure and low-friction hydraulic cylinder

Technical field

The invention belongs to the technical field of piston for high-pressure and low-friction hydraulic cylinders. In particular, it relates to a piston assembly for a high-pressure, low-friction hydraulic cylinder.

Background technique

Currently, in some high-pressure and low-friction hydraulic cylinders, constant gap seals are used to reduce friction. However, this seal cannot completely prevent leakage due to the existence of gaps. When the pressure difference on both sides of the piston is large, the leakage will be large, causing the hydraulic cylinder to The volumetric efficiency is reduced, so the sealing performance is poor. In addition, this kind of seal has high requirements on the geometric shape and surface processing accuracy of the parts, and it cannot automatically compensate after wear.

The Grain ring seal must be manufactured strictly in accordance with the hydraulic cylinder size requirements, and its elasticity is small and difficult to install. When the seal is worn, it is difficult to compensate for the worn sealing gap. If the fit is too tight, the seal and the inner wall of the cylinder will The destruction of the oil film will increase the friction, and it is difficult to ensure the lubrication performance of the sealing gap with the general structure.

Contents of the invention

The present invention aims to overcome the above technical shortcomings, and aims to provide a high-pressure and low-friction hydraulic system with low friction, high frequency response, high pressure resistance, good sealing performance, long working life, automatic adjustment of the sealing gap, and convenient disassembly and assembly. Cylinder piston assembly.

In order to achieve the above object, the technical solution adopted by the present invention is: the piston assembly of the high-pressure and low-friction hydraulic cylinder is composed of a support ring, a sealing ring assembly, a sealing ring and a piston.

There are support ring grooves symmetrically opened on the cylindrical surface of the piston near both sides, and support rings are respectively installed in the two support ring grooves; the width of the support ring groove is the same as the width of the support ring, and the depth of the support ring groove is the same as the width of the support ring. Same thickness.

There is a sealing groove in the center of the two support ring grooves of the piston. A sealing ring is installed at the bottom of the sealing groove. A sealing ring assembly is set close to the outer wall of the sealing ring; the width of the sealing groove is the same as the width of the sealing ring and the sealing ring assembly. The width is the same, and the depth of the sealing groove is the sum of the thickness of the sealing ring and the thickness of the sealing ring assembly.

The sealing ring assembly is a complete annular shape composed of a sealing ring and a rubber pad. The arc length of the rubber pad is 0.005 to 0.01 times that of the complete annular shape; the cross-section of the sealing ring is rectangular, and the cross-section of the rubber pad is the same as the cross-section of the sealing ring. same.

One end of the sealing ring connected to the rubber pad is a concave curved surface, and the other end is a convex curved surface. The intersections between the concave and convex curved surfaces of the sealing ring and the outer wall of the sealing ring are arc-shaped. The arcs at both ends of the sealing ring are The radius of curvature is 0.5 to 0.55 times the width of the sealing ring; one end of the rubber pad connected to the sealing ring is a corresponding convex curved surface, and the other end is a corresponding concave curved surface. The concave and convex curved surfaces of the rubber pad are in contact with the rubber The intersection lines of the outer walls of the pad are all arc-shaped, and the arc curvature radii at both ends of the rubber pad are 0.5 to 0.55 times the width of the rubber pad.

Large blind holes are evenly opened on the outer wall of the sealing ring. The large blind holes are located on the center line of the sealing ring. The spacing between the large blind holes is 3.5 to 4 times the width of the sealing ring; they pass through the center of the large blind holes and are in contact with the sealing ring. There are two small blind holes respectively opened in the direction of the center line at positive 45° and negative 45°. The distance between each small blind hole and the adjacent small blind hole is 0.6 to 0.7 times the width of the sealing ring.

The sealing ring is a circular broken ring. One end of the break is a concave curved surface and the other end is a convex curved surface. The intersections between the concave and convex curved surfaces of the sealing ring and the outer wall of the sealing ring are arc-shaped. The radius of curvature of the arc at both ends of the ring is 0.5 to 0.55 times the width of the sealing ring; the two sides of the sealing ring are symmetrical annular concave surfaces; the cross-section of the annular concave surface is arc-shaped, and the two sides of the sealing ring are The radius of curvature of the arc is 0.5 to 0.55 times the thickness of the sealing ring.

The thickness of the sealing ring is 0.5 to 0.6 times the depth of the sealing groove, and the material of the sealing ring is aluminum bronze alloy material.

The thickness of the sealing ring is 0.4 to 0.5 times the depth of the sealing groove; the sealing ring is made of fluorine rubber.

The rubber pad is made of fluorine rubber.

The diameter of the large blind hole is 0.15-0.2 times the width of the sealing ring, and the depth of the large blind hole is 0.16-0.18 times the thickness of the sealing ring.

The diameter of the small blind hole is 0.1 to 0.15 times the width of the sealing ring, and the depth of the small blind hole is 0.1 to 0.15 times the thickness of the sealing ring.

Due to the adoption of the above technical solution, the present invention has the following advantages compared with the prior art:

(1) The present invention processes multiple sets of blind holes on the outer wall of the sealing ring. Each set of blind holes is composed of four small blind holes and one large blind hole. There is hydraulic oil in each set of blind holes. When the piston moves, the blind holes The hydraulic oil in the hole is brought out, and an oil film is automatically formed in the gap between the piston and the inner wall of the cylinder, reducing friction and improving lubrication and sealing performance.

(2) In the present invention, concave curved surfaces are processed on both sides of the sealing ring. Under the action of high-pressure oil, its lips open outwards. The higher the hydraulic oil pressure, the wider the lips open, so that the hydraulic cylinder can withstand high pressure. , can also enhance sealing performance.

(3) In the present invention, a rubber pad is installed at the fracture of the sealing ring, which not only prevents high-pressure oil from leaking from the circular fracture opening, but also facilitates disassembly and assembly.

(4) The sealing ring of the present invention is made of aluminum bronze alloy with certain elastic deformation. It has a small friction coefficient and can speed up the response frequency of the hydraulic cylinder. When there is slight wear on its surface, the sealing ring is disconnected, so it can Freely expands outward to compensate for the slightly worn gap, improves the working life of the sealing ring, and automatically adjusts the sealing gap to prevent leakage.

Therefore, the invention has the characteristics of low friction, high frequency response, high pressure resistance, good sealing performance, long working life, automatic adjustment of the sealing gap and convenient disassembly and assembly, and is suitable for high pressure and low friction hydraulic cylinders.

Description of the drawings

Figure 1 is a structural schematic diagram of the present invention;

Figure 2 is a schematic structural diagram of the piston 4 in Figure 1;

Figure 3 is a partially enlarged schematic diagram of I in Figure 1;

Figure 4 is a schematic structural diagram of the sealing ring assembly 2 in Figure 1;

Figure 5 is an expanded schematic view of the sealing ring assembly 2 in Figure 3;

Figure 6 is a schematic diagram of the direction A-A in Figure 5;

Figure 7 is a schematic diagram of the direction B-B in Figure 5;

Figure 8 is a schematic diagram of the shape of the sealing ring 3 in Figure 1;

Figure 9 is an expanded schematic view of the sealing ring 3 in Figure 3;

FIG. 10 is a schematic view along the line C-C in FIG. 9 .

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, which does not limit the scope of protection.

Example 1

A piston assembly for a high pressure, low friction hydraulic cylinder. The piston assembly of the high-pressure and low-friction hydraulic cylinder consists of a support ring 1, a sealing ring assembly 2, a sealing ring 3 and a piston 4.

As shown in Figures 1 and 2, support ring grooves 5 are symmetrically opened on the cylindrical surface of the piston 4 near both sides. The two support ring grooves 5 are respectively equipped with support rings 1; the width of the support ring groove 5 is the same as the support ring groove 5. The width of the ring 1 is the same and the depth of the support ring groove 5 is the same as the thickness of the support ring 1 .

As shown in Figures 1 to 3, there is a sealing groove 6 at the center of the two support ring grooves 5 of the piston 4. The bottom of the sealing groove 6 is equipped with a sealing ring 3, and a sealing ring is set close to the outer wall of the sealing ring 3. Component 2; the width of the sealing groove 6 is the same as the width of the sealing ring 3 and the width of the sealing ring component 2, and the depth of the sealing groove 6 is the sum of the thickness of the sealing ring 3 and the thickness of the sealing ring component 2.

As shown in Figure 4, the sealing ring assembly 2 is a complete annular shape composed of a sealing ring 7 and a rubber pad 8. The arc length of the rubber pad 8 is 0.005 to 0.008 times of the complete annular shape; the cross-section of the sealing ring 7 is Rectangular, the cross-section of the rubber gasket 8 is the same as that of the sealing ring 7 .

As shown in Figure 5, one end of the sealing ring 7 connected to the rubber gasket 8 is a concave curved surface, and the other end is a convex curved surface. The intersection lines of the concave and convex curved surfaces of the sealing ring 7 and the outer wall of the sealing ring 7 are uniform. It is arc-shaped, and the radius of curvature of the arc at both ends of the sealing ring 7 is 0.5 to 0.55 times the width of the sealing ring 7; one end of the rubber pad 8 connected to the sealing ring 7 is a corresponding convex curved surface, and the other end is a corresponding concave shape. Curved surfaces, the intersection lines of the concave and convex curved surfaces of the rubber pad 8 and the outer wall of the rubber pad 8 are all arc-shaped, and the arc curvature radii at both ends of the rubber pad 8 are 0.5 to 0.55 times the width of the rubber pad 8 .

As shown in Figures 5 and 6, large blind holes are evenly opened on the outer wall of the sealing ring 7. The large blind holes are located on the center line of the sealing ring 7. The spacing between the large blind holes is 3.5 to 4 times the width of the sealing ring 7. ; As shown in Figure 5 and Figure 7, there are two small blind holes that pass through the center of the large blind hole and are at a positive 45° and a negative 45° direction with the center line of the sealing ring 7. Each small blind hole is connected to the corresponding direction. The distance between adjacent small blind holes is 0.6 to 0.65 times the width of the sealing ring 7 .

As shown in Figure 8, the sealing ring 3 is a broken ring; as shown in Figure 9, one end of the disconnection is a concave curved surface, and the other end is a convex curved surface. The concave curved surface and convex curved surface of the sealing ring 3 The intersection lines with the outer wall of the sealing ring 3 are all arc-shaped, and the arc curvature radii at both ends of the sealing ring 3 are 0.5 to 0.55 times the width of the sealing ring 3; as shown in Figure 10, the two sides of the sealing ring 3 are symmetrical The cross section of the annular concave curved surface is arc-shaped, and the arc curvature radius on both sides of the sealing ring 3 is 0.5 to 0.55 times the thickness of the sealing ring 3.

The thickness of the sealing ring 7 is 0.5 to 0.55 times the depth of the sealing groove 6 , and the material of the sealing ring 7 is aluminum bronze alloy material.

The thickness of the sealing ring 3 is 0.4 to 0.45 times the depth of the sealing groove 6; the sealing ring 3 is made of fluorine rubber.

The rubber pad 8 is made of fluorine rubber.

The diameter of the large blind hole is 0.15 to 0.18 times the width of the sealing ring 7 , and the depth of the large blind hole is 0.16 to 0.17 times the thickness of the sealing ring 7 .

The diameter of the small blind hole is 0.1 to 0.15 times the width of the sealing ring 7 , and the depth of the small blind hole is 0.1 to 0.15 times the thickness of the sealing ring 7 .

Example 2

A piston assembly for a high pressure, low friction hydraulic cylinder. Except for the following technical parameters, this embodiment is the same as Embodiment 1:

The arc length of the rubber pad 8 is 0.007 to 0.01 times that of the complete ring;

The distance between each small blind hole and the adjacent small blind hole is 0.65 to 0.7 times the width of the sealing ring 7;

The thickness of the sealing ring 7 is 0.55 to 0.6 times the depth of the sealing groove 6;

The thickness of the sealing ring 3 is 0.45 to 0.5 times the depth of the sealing groove 6;

The diameter of the large blind hole is 0.17-0.2 times the width of the sealing ring 7 , and the depth of the large blind hole is 0.17-0.18 times the thickness of the sealing ring 7 .

Compared with the prior art, this specific implementation has the following advantages:

(1) In this specific embodiment, multiple groups of blind holes are processed on the outer wall of the sealing ring 7. Each group of blind holes is composed of four small blind holes and one large blind hole. There is hydraulic oil in each group of blind holes. When the piston 4 During movement, the hydraulic oil in the blind hole is brought out, and an oil film is automatically formed in the gap between the piston and the inner wall of the cylinder, reducing friction and improving lubrication and sealing performance.

(2) In this specific embodiment, concave curved surfaces are processed on both sides of the sealing ring 3. Under the action of high-pressure oil, its lips open outwards. The higher the hydraulic oil pressure, the wider the lips open, so that the hydraulic cylinder is It can also enhance sealing performance when withstanding high pressure.

(3) In this specific embodiment, a rubber gasket 8 is installed at the fracture of the sealing ring 7, which not only prevents high-pressure oil from leaking from the circular fracture opening, but also facilitates disassembly and assembly.

(4) The material of the sealing ring 7 in this specific embodiment is an aluminum bronze alloy with certain elastic deformation. It has a small friction coefficient and can speed up the response frequency of the hydraulic cylinder. When there is slight wear on its surface, the sealing ring 7 is disconnected. , so it can expand freely to compensate for the slightly worn gap, improve the working life of the sealing ring, and automatically adjust the sealing gap to prevent leakage.

Therefore, this specific embodiment has the characteristics of low friction, high frequency response, ability to withstand high pressure, good sealing performance, long working life, automatic adjustment of the sealing gap, and convenient disassembly and assembly, and is suitable for high-pressure and low-friction hydraulic cylinders.

Claims (4)

1. A piston assembly for a high-pressure and low-friction hydraulic cylinder, characterized in that the piston assembly is composed of a support ring (1), a sealing ring assembly (2), a sealing ring (3) and a piston (4); A support ring groove (5) is symmetrically opened on the cylindrical surface of the piston (4) near both sides. A support ring (1) is installed in the two support ring grooves (5); the width of the support ring groove (5) is equal to The width of the support ring (1) is the same, and the depth of the support ring groove (5) is the same as the thickness of the support ring (1); There is a sealing groove (6) at the center of the two support ring grooves (5) of the piston (4). A sealing ring (3) is installed at the bottom of the sealing groove (6), and is set close to the outer wall of the sealing ring (3). There is a sealing ring assembly (2); the width of the sealing groove (6) is the same as the width of the sealing ring (3) and the width of the sealing ring assembly (2), and the depth of the sealing groove (6) is the thickness of the sealing ring (3) and The sum of the thicknesses of the sealing ring components (2); The sealing ring assembly (2) is a complete annular shape composed of a sealing ring (7) and a rubber gasket (8). The arc length of the rubber gasket (8) is 0.005~0.01 times of the complete annular shape; sealing The cross section of the ring (7) is rectangular, and the cross section of the rubber gasket (8) is the same as that of the sealing ring (7); One end of the sealing ring (7) connected to the rubber gasket (8) is a concave curved surface, and the other end is a convex curved surface. The concave and convex curved surfaces of the sealing ring (7) intersect with the outer wall of the sealing ring (7). The lines are all arc-shaped, and the arc curvature radii at both ends of the sealing ring (7) are 0.5~0.55 times the width of the sealing ring (7); one end of the rubber gasket (8) connected to the sealing ring (7) is a corresponding convex The other end is a corresponding concave curved surface. The intersection lines of the concave curved surface and the convex curved surface of the rubber pad (8) and the outer wall of the rubber pad (8) are both arc-shaped. The arcs at both ends of the rubber pad (8) The radius of curvature is 0.5~0.55 times the width of the rubber pad (8); Large blind holes are evenly opened on the outer wall of the sealing ring (7). The large blind holes are located on the center line of the sealing ring (7). The spacing between the large blind holes is 3.5~4 times the width of the sealing ring (7); through There are two small blind holes at the center of the large blind hole and at positive 45° and negative 45° to the center line of the sealing ring (7). The distance between each small blind hole and the adjacent small blind hole is 0.6~0.7 times the width of the sealing ring (7); The sealing ring (3) is a broken ring. One end of the break is a concave curved surface and the other end is a convex curved surface. The concave curved surface and the convex curved surface of the sealing ring (3) are in contact with the outer wall of the sealing ring (3). The intersection lines are all arc-shaped, and the arc-shaped curvature radii at both ends of the sealing ring (3) are 0.5~0.55 times the width of the sealing ring (3); the two sides of the sealing ring (3) are symmetrical annular concave surfaces. ; The cross section of the annular concave curved surface is arc-shaped, and the arc curvature radius on both sides of the sealing ring (3) is 0.5~0.55 times the thickness of the sealing ring (3); The thickness of the sealing ring (7) is 0.5~0.6 times the depth of the sealing groove (6), and the material of the sealing ring (7) is aluminum bronze alloy material; The thickness of the sealing ring (3) is 0.4 to 0.5 times the depth of the sealing groove (6); the sealing ring (3) is made of fluorine rubber. 2. The piston assembly for a high-pressure and low-friction hydraulic cylinder according to claim 1, characterized in that the rubber pad (8) is made of fluorine rubber. 3. The piston assembly for a high-pressure and low-friction hydraulic cylinder according to claim 1, characterized in that the diameter of the large blind hole is 0.15~0.2 times the width of the sealing ring (7), and the depth of the large blind hole is 0.16~0.18 times the thickness of the sealing ring (7). 4. The piston assembly for a high-pressure and low-friction hydraulic cylinder according to claim 1, characterized in that the diameter of the small blind hole is 0.1 to 0.15 times the width of the sealing ring (7), and the depth of the small blind hole is 0.1~0.15 times the thickness of the sealing ring (7).