Piston sealing structure of hydraulic cylinder

Abstract

The utility model relates to the technical field of piston sealing structures, in particular to a piston sealing structure of a hydraulic cylinder. According to the technical scheme, the hydraulic cylinder comprises a cylinder body and a piston installed in the cylinder body in a sliding mode, a piston rod and a plurality of sealing rings are fixedly installed on the piston, the hydraulic cylinder further comprises a back pressure component installed in the piston, the back pressure component applies force towards one side of the cylinder body to the sealing rings, and the magnitude of pressure applied to the sealing rings is adjusted according to the magnitude of pressure borne by the piston. The oil pressure of hydraulic oil on the inner wall of the cylinder body acts on the pressing plate, and when the oil pressure in the cylinder body rises, the pressure applied to the sealing ring by the oil pressure in the oil cavity is increased. And when the oil pressure in the cylinder body is small, the oil pressure in the oil cavity is also reduced similarly, so that the pressure applied to the cylinder body by the sealing ring can be reduced under the condition that the sealing is not influenced, the abrasion of the sealing ring can be reduced, and the service life of the sealing ring can be prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of piston sealing structures, in particular to a piston sealing structure of a hydraulic cylinder. Background Art

[0002] A hydraulic cylinder, also known as an oil cylinder, is an actuator in a hydraulic system. It converts hydraulic energy into mechanical energy, achieving linear reciprocating motion or pushing objects. Hydraulic cylinders are widely used in various types of machinery and engineering equipment, such as excavators, cranes, presses, and mold equipment. A hydraulic cylinder consists of a cylinder body and a piston, with sealing rings installed between the cylinder body and piston. These sealing rings are essential for the proper functioning of the hydraulic cylinder. The elasticity of the sealing ring is one of its key characteristics in achieving the sealing function. By applying pressure to the oil cylinder, the sealing ring deforms to compensate for microscopic irregularities in the sealing surface, thereby reducing the possibility of leakage.

[0003] Generally speaking, within the seal's maximum pressure tolerance, the greater the pressure applied by the seal on the cylinder, the better the sealing effect. However, the greater the pressure, the greater the friction between the seal and the cylinder body or piston. This increased friction causes the seal to wear faster. Furthermore, the internal oil pressure of the same hydraulic cylinder varies under different loads. To extend the seal's service life, the pressure applied by the seal on the cylinder should be reduced under low loads and increased under high loads. Existing sealing structures cannot meet this requirement. Utility Model Content

[0004] The purpose of the utility model is to address the problems existing in the background technology and to propose a piston sealing structure for a hydraulic cylinder.

[0005] The technical solution of the utility model is: a piston sealing structure of a hydraulic cylinder, comprising a cylinder body and a piston slidably mounted in the cylinder body, a piston rod and a plurality of sealing rings fixedly mounted on the piston, and further comprising:

[0006] A counter-pressure component is installed in the piston, and the counter-pressure component applies a force to the sealing ring in the direction toward one side of the cylinder body, and adjusts the size of the pressure applied to the sealing ring according to the pressure on the piston.

[0007] Optionally, the back-pressure component includes a plurality of pressure grooves and oil chambers provided on the piston, the pressure grooves correspond one-to-one to and are connected with the oil chambers, the piston is provided with a plurality of mounting grooves for installing sealing rings, the pressure grooves correspond one-to-one to and are connected with the mounting grooves, and a compression assembly for compressing the internal volume of the oil chamber is installed inside the piston.

[0008] Optionally, a cavity is provided in the piston, and the compression assembly includes a plurality of compression rods slidably mounted inside the cavity, the compression rods extending into the oil chamber, a driving rod is slidably mounted on the piston, the driving rod passes through one side of the piston and extends into the cavity, a plurality of connecting rods are rotatably mounted on the driving rod, the connecting rods correspond one-to-one to the compression rods and are rotatably connected, a pressure plate is fixedly mounted on one end of the driving rod located on the outside of the piston, a rubber ring is fixedly mounted on the pressure plate, and the other end of the rubber ring is fixedly connected to the piston and sealed.

[0009] Optionally, a plurality of support cylinders are fixedly installed in the cavity, the support cylinders correspond to the compression rods one-to-one, the compression rods are located inside the support cylinders, and a sealing pressure ring is fixedly installed inside the support cylinders.

[0010] Optionally, a sliding groove is provided in the driving rod, a support rod is fixedly installed in the cavity, and the support rod is slidably connected to the sliding groove.

[0011] Optionally, a plug is fixedly mounted on one side of the piston, and the plug seals the cavity.

[0012] Optionally, the driving rod passes through the plug, and a sealing ring is fixedly installed in the plug, and the sealing ring rests on the driving rod.

[0013] In summary, this application includes at least one of the following beneficial technical effects:

[0014] The hydraulic oil pressure inside the cylinder acts on the pressure plate. When the internal oil pressure of the cylinder increases, it drives the compression rod to move into the oil chamber, thereby reducing the effective volume inside the oil chamber, thereby increasing the hydraulic oil pressure inside the oil chamber, and thus increasing the pressure exerted by the oil pressure inside the oil chamber on the sealing ring. This improves the sealing performance. When the internal oil pressure of the cylinder is low, the oil pressure inside the oil chamber will also decrease. This can reduce the pressure exerted by the sealing ring on the cylinder without affecting the seal, thereby reducing the wear of the sealing ring and extending the service life of the sealing ring. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A structural diagram of an embodiment of the present invention is given;

[0016] Figure 2 A schematic structural diagram of the piston and sealing ring of the utility model is given;

[0017] Figure 3 A structural diagram of the compression assembly of the utility model is given;

[0018] Figure 4 for Figure 1 A partial enlarged view of point A in the middle;

[0019] Figure 5 for Figure 1 A partial enlarged view of point B in the middle.

[0020] Figure numerals: 1. Cylinder body; 2. Piston; 201. Piston rod; 3. Sealing ring; 4. Pressure groove; 401. Oil chamber; 402. Compression rod; 403. Drive rod; 404. Connecting rod; 405. Pressure plate; 406. Rubber ring; 5. Support cylinder; 501. Sealing pressure ring; 6. Slide groove; 601. Support rod; 7. Cavity; 701. Plug; 702. Sealing ring. DETAILED DESCRIPTION

[0021] The technical solution of the present invention is further described below with reference to the accompanying drawings and specific embodiments.

[0022] Example

[0023] like Figure 1-5 As shown, the present invention proposes a piston sealing structure for a hydraulic cylinder, comprising a cylinder body 1 and a piston 2 slidably mounted in the cylinder body 1, a piston rod 201 and a plurality of sealing rings 3 fixedly mounted on the piston 2, and the deformation of the sealing ring 3 fills the microscopic unevenness of the sealing surface, thereby sealing the gap between the piston 2 and the cylinder body 1, thereby improving the sealing performance. It also includes a back-pressure component installed in the piston 2, which applies a force to the sealing ring 3 in the direction toward one side of the cylinder body 1, and adjusts the amount of pressure applied to the sealing ring 3 according to the pressure on the piston 2. When the internal oil pressure increases, by applying pressure to the sealing ring internally, the pressure applied by the sealing ring 3 on the cylinder body 1 can be increased, thereby improving the sealing performance, and the force is proportional to the oil pressure inside the cylinder body 1. The counter-pressure component includes multiple pressure grooves 4 and an oil chamber 401 on the piston. The pressure grooves 4 correspond to and communicate with the oil chamber 401. The piston 2 is provided with multiple mounting slots for sealing rings 3. The pressure grooves 4 correspond to and communicate with the mounting slots. A compression assembly is installed within the piston to compress the volume of the oil chamber 401. The oil chamber 401 is filled with hydraulic oil. When the space inside the oil chamber 401 is compressed, the oil pressure inside the oil chamber 401 increases. This oil pressure acts on the sealing ring 3, increasing the pressure applied by the sealing ring 3 to the cylinder body 1, thereby improving sealing performance.

[0024] Among them, a cavity 7 is provided in the piston 2, and the compression assembly includes a plurality of compression rods 402 slidably installed inside the cavity, and the compression rods 402 extend into the oil chamber 401. A driving rod 403 is slidably installed on the piston 2, and the driving rod 403 passes through one side of the piston 2 and extends into the cavity 7. A plurality of connecting rods 404 are rotatably installed on the driving rod 403, and the connecting rods 404 correspond to the compression rods 402 one by one and are rotatably connected. A pressure plate 405 is fixedly installed at one end of the driving rod 403 located on the outside of the piston 2, and a rubber ring 406 is fixedly installed on the pressure plate 405. The other end of the rubber ring 406 is fixedly connected to the piston 2 and sealed. When the oil pressure inside the cylinder 1 increases, the oil pressure will act on the pressure plate 405, causing the pressure plate 405 to move in the direction close to the piston 2, which can drive the drive rod 403 to move. The moving drive rod 403 will drive the compression rod 402 to move inside the oil chamber 401, thereby reducing the effective volume inside the oil chamber 401, thereby increasing the oil pressure of the hydraulic oil inside the oil chamber 401, and thus increasing the pressure exerted by the oil pressure in the oil chamber 401 on the sealing ring 3. In turn, the sealing performance is improved. When the oil pressure inside the cylinder 1 is low, the oil pressure inside the oil chamber 401 will also decrease. In turn, the pressure exerted by the sealing ring 3 on the cylinder can be reduced without affecting the seal, thereby reducing the wear of the sealing ring.

[0025] Furthermore, multiple support cylinders 5 are fixedly installed in the cavity 7. The support cylinders 5 correspond one to one with the compression rods 402. The compression rods 402 are located inside the support cylinders 5. A sealing pressure ring 501 is fixedly installed inside the support cylinders 5. The compression rods 402 are guided by the support cylinders 5, and the sealing pressure ring 501 fills the gap between the compression rods 402 and the support cylinders 5 to prevent the hydraulic oil inside the oil cavity 401 from flowing out.

[0026] Among them, the driving rod 403 is provided with a sliding groove 6, and the cavity 7 is fixedly installed with a support rod 601, which is slidably connected to the sliding groove 6. The driving rod 403 is guided by the support rod 601 and the sliding groove 6.

[0027] Furthermore, a plug 701 is fixedly mounted on one side of the piston 2 to seal the cavity 7. A seal is provided at the contact point between the plug 701 and the cavity 7 to prevent hydraulic oil from entering the cylinder 1 into the cavity 7. The drive rod 403 passes through the plug 701. A sealing ring 702 is fixedly mounted inside the plug 701 and abuts against the drive rod 403. The sealing ring 702 seals the gap between the drive rod 403 and the plug 701 to prevent hydraulic oil from entering the cavity 7.

[0028] Working principle: The hydraulic oil pressure on the inner wall of the cylinder body 1 will act on the pressure plate 405. When the oil pressure inside the cylinder body 1 increases, the pressure plate 405 tends to move in the direction close to the piston 2, which can drive the drive rod 403 to move. The moving drive rod 403 will drive the compression rod 402 to move inside the oil chamber 401, thereby reducing the effective volume inside the oil chamber 401, thereby increasing the oil pressure of the hydraulic oil inside the oil chamber 401, thereby increasing the pressure exerted by the oil pressure inside the oil chamber 401 on the sealing ring 3. In this way, the sealing performance is improved. When the oil pressure inside the cylinder body 1 is low, the oil pressure inside the oil chamber 401 will also decrease. In this way, the pressure exerted by the sealing ring 3 on the cylinder body can be reduced without affecting the seal, thereby reducing the wear of the sealing ring.

[0029] The above specific embodiments are merely several optional embodiments of the present invention. Based on the technical solutions of the present invention and the relevant teachings of the above embodiments, those skilled in the art may make various alternative improvements and combinations to the above specific embodiments.

Claims

1. A piston sealing structure of a hydraulic cylinder, comprising a cylinder body (1) and a piston (2) slidably mounted in the cylinder body (1), wherein a piston rod (201) and a plurality of sealing rings (3) are fixedly mounted on the piston (2), characterized in that: Also includes: A counter-pressure component is installed in the piston (2), and the counter-pressure component applies a force to the sealing ring (3) in the direction toward one side of the cylinder body (1), and adjusts the pressure applied to the sealing ring (3) according to the pressure applied to the piston (2).

2. The piston sealing structure of a hydraulic cylinder according to claim 1, characterized in that: The counter-pressure component comprises a plurality of pressure grooves (4) and an oil chamber (401) provided on the piston, wherein the pressure grooves (4) correspond to and are connected with the oil chamber (401) one by one, and the piston (2) is provided with a plurality of mounting grooves for mounting a sealing ring (3), wherein the pressure grooves (4) correspond to and are connected with the mounting grooves one by one, and a compression component for compressing the internal volume of the oil chamber (401) is installed inside the piston.

3. The piston sealing structure of a hydraulic cylinder according to claim 2, characterized in that: A cavity (7) is provided in the piston (2), and the compression assembly comprises a plurality of compression rods (402) slidably mounted inside the cavity, the compression rods (402) extending into the oil chamber (401), a driving rod (403) slidably mounted on the piston (2), the driving rod (403) penetrating one side of the piston (2) and extending into the cavity (7), a plurality of connecting rods (404) are rotatably mounted on the driving rod (403), the connecting rods (404) corresponding to the compression rods (402) one by one and rotatably connected, a pressure plate (405) is fixedly mounted on one end of the driving rod (403) located outside the piston (2), a rubber ring (406) is fixedly mounted on the pressure plate (405), and the other end of the rubber ring (406) is fixedly connected to the piston (2) and sealed.

4. The piston sealing structure of a hydraulic cylinder according to claim 3, characterized in that: A plurality of support tubes (5) are fixedly installed in the cavity (7), the support tubes (5) correspond to the compression rods (402) one by one, the compression rods (402) are located inside the support tubes (5), and a sealing pressure ring (501) is fixedly installed inside the support tubes (5).

5. The piston sealing structure of a hydraulic cylinder according to claim 4, characterized in that: A slide groove (6) is provided in the driving rod (403), a support rod (601) is fixedly installed in the cavity (7), and the support rod (601) is slidably connected to the slide groove (6).

6. The piston sealing structure of a hydraulic cylinder according to claim 5, characterized in that: A plug (701) is fixedly mounted on one side of the piston (2), and the plug (701) seals the cavity (7).

7. The piston sealing structure of a hydraulic cylinder according to claim 6, characterized in that: The driving rod (403) passes through the plug (701), and a sealing ring (702) is fixedly installed in the plug (701), and the sealing ring abuts against the driving rod (403).

Images