A low-friction piston rod seal structure for a hydraulic cylinder

Abstract

The utility model provides a kind of low friction piston rod sealing structure of hydraulic cylinder, it is set between the cylinder body and piston rod of hydraulic cylinder, the cylinder body includes cylinder cover, bearing is provided on the piston rod, including dust ring, main seal and ster seal, the dust ring is close to the cylinder cover and is set, the main seal is close to the dust ring and is set, the ster seal is close to the main seal and is set;The ster seal is close to the bearing and is set, recess is also provided on the cylinder cover, the recess is located between the main seal and the ster seal;It can effectively reduce kinetic friction, avoid hydraulic cylinder to appear jitter abnormal sound, prolong the working life of sealing system.

Description

Technical Field

[0001] This utility model relates to the field of sealing structures, specifically to a low-friction piston rod sealing structure for a hydraulic cylinder. Background Technology

[0002] A hydraulic cylinder is a hydraulic actuator that converts hydraulic energy into mechanical energy and performs linear reciprocating motion. It has a simple structure and reliable operation, and is widely used in the hydraulic systems of various machines.

[0003] Hydraulic cylinders are used in different applications and have different operating requirements. In some special operating conditions, such as machine tools and servo cylinders, low friction is required, or hydraulic cylinders that are prone to vibration and abnormal noise need to adopt a piston rod sealing structure with low friction to achieve the stability of the sealing system. Utility Model Content

[0004] The purpose of this invention is to solve the above problems and provide a low-friction piston rod sealing structure for hydraulic cylinders, which can effectively reduce motion friction, prevent hydraulic cylinders from vibrating and making abnormal noises, and extend the working life of the sealing system.

[0005] To achieve the above objectives, the present invention adopts the following technical solution.

[0006] A low-friction piston rod sealing structure for a hydraulic cylinder is disposed between the cylinder body and the piston rod of the hydraulic cylinder. The cylinder body includes a cylinder head, and a bearing is disposed on the piston rod. The structure includes a dust seal, a main seal, and a step seal. The dust seal is disposed near the cylinder head, the main seal is disposed near the dust seal, and the step seal is disposed near the main seal. The step seal is disposed near the bearing. A groove is also disposed on the cylinder head, and the groove is located between the main seal and the step seal.

[0007] Furthermore, the dustproof ring includes an O-ring and a slip ring.

[0008] Furthermore, the slip ring is made of polytetrafluoroethylene.

[0009] Furthermore, the main seal includes a sealing ring and a support ring.

[0010] Furthermore, the sealing ring is a lip-shaped sealing ring.

[0011] Furthermore, the lip seal is made of rubber.

[0012] Furthermore, the support ring is made of polytetrafluoroethylene.

[0013] Furthermore, the support ring is L-shaped.

[0014] The positive effects of this utility model's low-friction piston rod sealing structure for hydraulic cylinders are:

[0015] The dust seal consists of a rubber O-ring and a PTFE slip ring, providing excellent sealing, low friction, and preventing creeping at low speeds. The main seal consists of a rubber lip seal and an L-shaped PTFE support ring, offering high pressure resistance and excellent sealing. The groove design prevents oil accumulating and pressure trapping between the main seal and the step seal, further reducing friction. The bearings are oil-free, featuring low friction and high load capacity, providing excellent support and guidance for the hydraulic cylinder. Attached Figure Description

[0016] Figure 1 This is a schematic diagram provided by an embodiment of the present utility model.

[0017] The labels in the diagram are as follows:

[0018] 1. Cylinder head; 2. Dust seal; 3. Main seal; 4. Groove; 5. Step seal; 6. Bearing. Detailed Implementation

[0019] The following describes a specific embodiment of a low-friction piston rod sealing structure for a hydraulic cylinder according to the present invention, with reference to the accompanying drawings. However, it should be noted that the specific embodiments described are not intended to limit the specific implementation of the present invention. Any similar structures or variations thereof employing the present invention should be included within the protection scope of the present invention. The following description of the embodiments is based on the accompanying drawings and is used to illustrate specific embodiments in which the present invention can be implemented. Directional terms mentioned in the embodiments, such as "up," "down," "front," "back," "left," "right," "top," and "bottom," are only for reference to the accompanying drawings. Therefore, the directional terms used are for the purpose of explaining and understanding the present invention, and not for limiting the present invention.

[0020] See Figure 1 A low-friction piston rod sealing structure for a hydraulic cylinder is disposed between the cylinder body and the piston rod. The cylinder body includes a cylinder head 1, and the piston rod is provided with a bearing 6. The structure includes a dust seal 2, a main seal 3, and a step seal 5. The dust seal 2 is located near the cylinder head 1, the main seal 3 is located near the dust seal 2, and the step seal 5 is located near the main seal 3. The step seal 5 is located near the bearing 6. The cylinder head 1 also has a groove 4 located between the main seal 3 and the step seal 5. The dust seal 2 includes an O-ring and a slip ring, the slip ring being made of polytetrafluoroethylene (PTFE). The main seal 3 includes a sealing ring and a support ring, the sealing ring being a lip seal made of rubber.

[0021] The support ring is made of polytetrafluoroethylene (PTFE) and is L-shaped. The inner ring of the L-shaped PTFE support ring has multiple oil reservoirs to reduce the contact area and provide low friction. A main seal 3 is located on the right side of the dustproof ring 2. The main seal 3 consists of a rubber lip seal and an L-shaped PTFE support ring, providing good sealing performance while maintaining low friction. A groove 4 is located on the right side of the main seal 3. The groove 4 can store residual oil film, preventing oil accumulation and pressure trapping between the main seal 3 and the step seal 5.

[0022] Bearing 6 is an oil-free bearing with a polytetrafluoroethylene (PTFE) coating on its inner ring, resulting in low dynamic friction and providing support and guidance for the hydraulic cylinder. The sliding surface of the step seal 5 is made of PTFE, exhibiting extremely low kinetic friction, serving as the first seal to protect the main seal 3.

[0023] During installation, the dust seal 2, main seal 3, step seal 5, and oil-free bearing are installed into the corresponding grooves of the end cover. Groove 4 is pre-machined during the end cover machining process. The oil-free bearing supports and guides the hydraulic cylinder, ensuring the coaxiality of the piston rod when the hydraulic cylinder is subjected to large lateral loads. Step seal 5 and main seal 3 seal the rod chamber of the hydraulic cylinder. The PTFE material of the sliding surface has an extremely low coefficient of friction, preventing vibration and creeping issues at low speeds. Groove 4 can store the oil film passing through step seal 5, preventing oil accumulation between main seal 3 and step seal 5 from causing pressure trapping, tightening the seal, increasing friction, and accelerating seal wear. The dust seal 2 combines sealing and dust prevention functions. The dust lip scrapes away external contaminants adhering to the piston rod, while the sealing lip retains residual oil film carried by the piston rod when it extends, resulting in low friction and no creeping at low speeds.

[0024] Dust seal 2, main seal 3, and step seal 5 employ a combined seal. The sliding surfaces are made of PTFE material, which has low friction, good sealing effect, and wear resistance. The oil-free bearing has low friction and high load capacity, providing excellent support and guidance for the hydraulic cylinder. The groove 4 design effectively prevents oil accumulating and pressure trapping between the main seal 3 and step seal 5.

[0025] The dustproof ring 2 is composed of a rubber O-ring and a PTFE slip ring, providing good sealing performance, low friction during movement, and preventing creeping at low speeds; the main seal 3 is composed of a rubber lip seal and an L-shaped PTFE support ring, offering high pressure resistance and good sealing performance; the groove 4 design prevents oil accumulating and pressure trapping between the main seal 3 and the step seal 5, and the oil storage groove design further reduces friction; the bearing 6 is an oil-free bearing, featuring low friction and high load capacity, providing excellent support and guidance for the hydraulic cylinder.

Claims

1. A low-friction piston rod sealing structure for a hydraulic cylinder, disposed between the cylinder body and the piston rod of the hydraulic cylinder, wherein the cylinder body includes a cylinder head and a bearing is disposed on the piston rod, characterized in that, It includes a dust seal, a main seal, and a step seal. The dust seal is located near the cylinder head, the main seal is located near the dust seal, and the step seal is located near the main seal. The step seal is located near the bearing. The cylinder head also has a groove located between the main seal and the step seal.

2. The low-friction piston rod sealing structure of the hydraulic cylinder according to claim 1, characterized in that, The dustproof ring includes an O-ring and a slip ring.

3. The low-friction piston rod sealing structure of the hydraulic cylinder according to claim 2, characterized in that, The slip ring is made of polytetrafluoroethylene.

4. The low-friction piston rod sealing structure of the hydraulic cylinder according to claim 1, characterized in that, The main seal includes a sealing ring and a support ring.

5. The low-friction piston rod sealing structure of the hydraulic cylinder according to claim 4, characterized in that, The sealing ring is a lip-shaped sealing ring.

6. The low-friction piston rod sealing structure of the hydraulic cylinder according to claim 5, characterized in that, The lip seal is made of rubber.

7. The low-friction piston rod sealing structure of the hydraulic cylinder according to claim 4, characterized in that, The support ring is made of polytetrafluoroethylene.

8. The low-friction piston rod sealing structure of the hydraulic cylinder according to claim 7, characterized in that, The support ring is L-shaped.

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