A novel rod sealing system with a wide temperature range

Abstract

This application relates to the technical field of rod sealing, and particularly to a novel rod sealing system with a wide temperature range, comprising a dust seal, a main seal, a buffer seal, and an oil-free bearing arranged sequentially along the axial direction. The dust seal includes a slip ring made of PTFE material and a rubber ring made of EPDM rubber, the rubber ring being fitted over the slip ring. The main seal includes a compression rod seal made of high-temperature resistant polyurethane material and a low-temperature resistant O-ring with high elasticity, installed inside the lip of the compression rod seal. The buffer seal includes a seal body made of high-temperature resistant polyurethane material and a retaining ring made of low-temperature resistant material. This application has the advantage of expanding the temperature range.

Description

Technical Field

[0001] This application relates to the technical field of rod seals, and in particular to a novel rod seal system with a wide temperature range. Background Technology

[0002] Among the many industrial equipment and mechanical devices involving hydraulic systems, the rod sealing system plays a crucial role, and its performance directly affects the operational stability, reliability, and service life of the equipment.

[0003] As shown in Figure 1, the currently widely used conventional rod sealing system mainly consists of a dust seal 1, a main seal 2, a guide ring 3, and a buffer seal 4. This system adopts a series combination structure of the buffer seal, U-shaped main seal, dust seal, and guide ring, which can meet the sealing requirements under common working conditions to a certain extent, and its temperature resistance range is usually maintained between -30℃ and +110℃.

[0004] However, when the temperature conditions of the equipment's operating environment exceed this range, conventional rod sealing systems will expose many problems.

[0005] In low-temperature environments, especially below -30°C, key components in this system, such as the main seal, often use polyurethane. Polyurethane hardens at low temperatures, losing its original resilience. In this situation, the fit between the seal and the piston rod is severely affected during the reciprocating motion of the cylinder. The previously tight seal is broken, the sealing gap increases, and hydraulic oil leaks more easily, drastically increasing the probability of rod leakage. Rod leakage not only wastes hydraulic oil and increases operating costs, but can also pollute the work area, affect the normal operation of surrounding equipment, and even pose safety hazards.

[0006] In high-temperature environments, such as outdoors in summer, when the hydraulic cylinder is exposed to intense sunlight and during reciprocating motion, the surface temperature of the piston rod can easily rise above 110°C. Under such high-temperature conditions, the polyurethane main seal in a conventional rod sealing system faces severe challenges. High temperatures cause high-temperature degradation of the polyurethane material, gradually altering its physical properties and chemical structure, leading to problems such as cracking. Once the main seal cracks, the sealing function will significantly decrease or even fail, and hydraulic oil will leak through the crack, eventually causing oil to be carried along the cylinder rod. This not only affects the sealing performance of the hydraulic cylinder and reduces equipment efficiency, but may also cause corrosion and damage to other internal components due to hydraulic oil leakage, increasing equipment maintenance costs and downtime, seriously affecting production progress and the company's economic benefits. Utility Model Content

[0007] To extend the temperature resistance range, this application provides a novel rod sealing system with a wide temperature resistance range.

[0008] This application provides a novel rod sealing system with a wide temperature range, employing the following technical solution:

[0009] A novel rod sealing system with a wide temperature range includes a dust seal, a main seal, a buffer seal, and an oil-free bearing arranged sequentially along the axial direction. The dust seal includes a slip ring made of PTFE material and a rubber ring made of EPDM rubber, with the rubber ring fitted over the slip ring. The main seal includes a compression rod seal made of high-temperature resistant polyurethane material and a low-temperature resistant O-ring with high elasticity, installed inside the lip of the compression rod seal. The buffer seal includes a seal body made of high-temperature resistant polyurethane material and a retaining ring made of low-temperature resistant material.

[0010] In one embodiment: the end face of the slip ring that contacts the cylinder rod is provided with a first sealing lip and a second sealing lip, the first sealing lip and the second sealing lip are spaced apart, the contact surface between the first sealing lip and the cylinder rod is larger than the second sealing lip, and the first sealing lip is located on the side away from the main seal.

[0011] In one embodiment, the rubber ring consists of two O-rings.

[0012] In one embodiment: the centers of both O-rings are located between the first sealing lip and the second sealing lip, and are respectively located close to the first sealing lip and the second sealing lip.

[0013] In one embodiment, the depth of the recess formed between the first sealing lip and the second sealing lip is no greater than one-quarter of the thickness of the slip ring.

[0014] In one embodiment, the material of the clamping rod seal ring is high-temperature resistant PPDI material.

[0015] In one embodiment, the low-temperature resistant O-ring is made of low-temperature resistant nitrile rubber.

[0016] In one embodiment: the material of the sealing element body is high-temperature resistant PPDI polyurethane.

[0017] In one embodiment, the retaining ring is made of modified nylon.

[0018] In one embodiment, the oil-free bearing is made of a metal base material.

[0019] In summary, the guide ring, replaced with an oil-free bearing instead of ordinary phenolic resin-reinforced fabric, offers advantages such as good thermal conductivity and a low coefficient of friction, making it suitable for medium to high loads and speeds. Its long-term operating temperature range is -50℃ to +250℃. The buffer seal ensures sealing at low temperatures through a retaining ring, while the seal body ensures sealing at high temperatures. The main seal ensures sealing at high temperatures through a clamping rod seal ring, and a low-temperature resistant O-ring ensures sealing at low temperatures. The slip ring and rubber ring used in the dust seal both possess the advantages of high and low temperature resistance. The applicable operating temperature of PTFE material is -200℃ to +260℃, and that of EPDM rubber is -50℃ to +150℃. Therefore, the operating temperature range of the dust seal is -50℃ to +150℃, thus expanding the overall temperature resistance range of the sealing system. Attached Figure Description

[0020] Figure 1 This is a structural schematic diagram of an existing rod sealing system;

[0021] Figure 2 This is a schematic diagram of the structure of the novel rod sealing system with a wide temperature range in this embodiment;

[0022] Figure 3 This is a schematic diagram of the dustproof ring in the novel rod sealing system with a wide temperature range in this embodiment.

[0023] In the diagram, 100 is the dustproof ring; 110 is the slip ring; 111 is the first sealing lip; 112 is the second sealing lip; 120 is the rubber ring; 200 is the main seal; 210 is the clamping rod seal; 220 is the low-temperature resistant O-ring; 300 is the buffer seal; 310 is the seal body; 320 is the retaining ring; and 400 is the oil-free bearing. Detailed Implementation

[0024] The present application will be further described in detail below with reference to the accompanying drawings.

[0025] In the description of this application, it should be understood that the terms "upper", "lower", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0026] A novel rod sealing system with a wide temperature range, such as Figure 2 As shown, it includes a dustproof ring 100, a main seal 200, a buffer seal 300, and an oil-free bearing 400 arranged sequentially along the axial direction.

[0027] The dustproof ring 100 includes a slip ring 110 and a rubber ring 120, with the rubber ring 120 fitted over the slip ring 110.

[0028] See attached document Figure 3 The slip ring 110 is made of PTFE material. The end face of the slip ring 110 that contacts the cylinder rod is provided with a first sealing lip 111 and a second sealing lip 112. The first sealing lip 111 and the second sealing lip 112 are spaced apart. The contact surface between the first sealing lip 111 and the cylinder rod is larger than that between the first sealing lip 111 and the cylinder rod. The first sealing lip 111 is located on the side away from the main seal 200.

[0029] The first sealing lip 111 has one end face away from the main seal 200 that is arranged in the radial direction of the cylinder rod, and the other side is inclined towards the main seal 200. The second sealing lip 112 has both sides that are inclined to form an overall conical structure. In this way, by using the first sealing lip 111 as the main sealing structure, dust and other substances can be prevented from entering while resistance can be reduced as much as possible.

[0030] The tilt angle of the tilted side of the second sealing lip 112 is less than the tilt angle of the side of the second sealing lip 112 away from the main seal 200, so that the connection position of the two tilted sides is close to the first sealing lip 111. The two tilted sides are set to form the gap between the first sealing lip 111 and the second sealing lip 112, and the depth a of the recess formed by the two tilted sides is not greater than one-quarter of the thickness b of the slip ring 110.

[0031] The rubber ring 120 is made of EPDM rubber and consists of two O-rings. The centers of the two O-rings are located between the first sealing lip 111 and the second sealing lip 112, and are positioned close to the first and second sealing lips 111 and 112, respectively. Thus, the tightening force of the rubber ring 120 acts between the first and second sealing lips 111 and 112, and its proximity to the first and second sealing lips 111 and 112 ensures that the tightening force of the rubber ring 120 is effectively applied to the first and second sealing lips 111 and 112. The shallow depth of the recess 'a' prevents the tightening force of the rubber ring 120 from deforming the slip ring 110 and failing to effectively transmit the force to the first and second sealing lips 111 and 112.

[0032] like Figure 2 As shown, the main seal 200 includes a clamping rod seal ring 210 and a low-temperature resistant O-ring 220. The clamping rod seal ring 210 is made of high-temperature resistant polyurethane material. In this embodiment, high-temperature resistant PPDI material is used. This polyurethane material is suitable for long-term operation at 125°C.

[0033] A low-temperature resistant O-ring 220 is installed inside the lip of the clamping rod seal 210. The low-temperature resistant O-ring 220 is made of low-temperature resistant nitrile rubber, which has high elasticity and can maintain good resilience even at -45℃. Thus, the long-term operating temperature range of the main seal 200 is -45℃ to +125℃.

[0034] The function of the buffer seal is to delay the transmission of working oil temperature (high temperature) to the piston rod main seal and reduce the pressure of the main seal. The buffer seal does not require "zero leakage". In fact, allowing a certain amount of oil film to pass through the buffer seal can increase the lubrication of the main seal and reduce the wear of the main seal.

[0035] In this embodiment, the buffer seal 300 includes a seal body 310 and a retaining ring 320. The seal body 310 is made of high-temperature resistant polyurethane material, specifically high-temperature resistant PPDI polyurethane in this embodiment. The retaining ring 320 is made of low-temperature resistant material, specifically modified nylon in this embodiment. Through the above configuration, the buffer seal 300 has excellent wear resistance and media resistance, and can adapt to a long-term operating temperature range of -45℃ to +125℃.

[0036] The oilless bearing 400 is made of metal, which gives it the advantages of good thermal conductivity and low coefficient of friction. It is suitable for medium and high loads and speeds, and its long-term operating temperature range is -50℃ to +250℃.

[0037] In summary, the guide ring has been changed from ordinary phenolic resin-reinforced fabric to oil-free bearing 400, which has the advantages of good thermal conductivity and low coefficient of friction, making it suitable for medium to high loads and speeds. Its long-term operating temperature range is -50℃ to +250℃. The buffer seal ensures sealing at low temperatures through the retaining ring 320, while the seal body 310 ensures sealing at high temperatures. The main seal 200 ensures sealing at high temperatures through the clamping rod seal ring 210, and the low-temperature resistant O-ring 220 ensures sealing at low temperatures. The slip ring 110 and rubber ring 120 used in the dustproof ring 100 both have the advantages of high temperature resistance and low temperature resistance. The applicable working temperature of PTFE material is -200℃ to +260℃, and the applicable working temperature of EPDM rubber is -50℃ to +150℃. Therefore, the working temperature range of the dustproof ring 100 is -50℃ to +150℃. This expands the overall temperature resistance range of the sealing system. Compared with the conventional rod sealing system with a temperature resistance range of -30℃ to +110℃, the temperature resistance range of this new structure piston rod sealing system is -45℃ to +125℃, which is a wider temperature resistance range.

[0038] The embodiments described in this specific implementation are preferred embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A new rod seal system with a wide temperature range, characterized by: The device includes a dustproof ring (100), a main seal (200), a buffer seal (300), and an oil-free bearing (400) arranged sequentially along the axial direction. The dustproof ring (100) includes a slip ring (110) made of PTFE material and a rubber ring (120) made of EPDM rubber. The rubber ring (120) is fitted over the slip ring (110). The main seal (200) includes a clamping rod seal (210) made of high-temperature resistant polyurethane material and a low-temperature resistant O-ring (220) with high elasticity installed inside the lip of the clamping rod seal (210). The buffer seal (300) includes a seal body (310) made of high-temperature resistant polyurethane material and a retaining ring (320) made of low-temperature resistant material.

2. A new type of rod seal system with wide temperature range according to claim 1, characterized in that: The slip ring (110) has a first sealing lip (111) and a second sealing lip (112) on the end face that contacts the cylinder rod. The first sealing lip (111) and the second sealing lip (112) are spaced apart. The contact surface between the first sealing lip (111) and the cylinder rod is larger than that between the first sealing lip (112) and the second sealing lip (112). The first sealing lip (111) is located on the side away from the main seal (200).

3. A new type of rod seal system with wide temperature range according to claim 2, characterized in that: The rubber ring (120) consists of two O-rings.

4. A new type of rod seal system with wide temperature range according to claim 3, characterized in that: The centers of both O-rings are located between the first sealing lip (111) and the second sealing lip (112), and are respectively located close to the first sealing lip (111) and the second sealing lip (112).

5. A new type of rod seal system with wide temperature range according to claim 4, characterized in that: The depth of the recess formed between the first sealing lip (111) and the second sealing lip (112) is no greater than one-quarter of the thickness of the slip ring (110).

6. A new type of rod seal system with wide temperature range according to claim 1, characterized in that: The material of the clamping rod seal ring (210) is high-temperature resistant PPDI material.

7. A new type of rod seal system with wide temperature range according to claim 1, characterized by: The material of the low-temperature resistant O-ring (220) is low-temperature resistant nitrile rubber.

8. A new type of rod seal system with wide temperature range according to claim 1, characterized by: The material of the sealing element body (310) is high-temperature resistant PPDI polyurethane.

9. A new type of rod seal system with wide temperature range according to claim 1, characterized by: The retaining ring (320) is made of modified nylon.

10. A new type of rod seal system with wide temperature range according to claim 1, characterized by: The oil-free bearing (400) is made of a metal base material.

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