Low-wear piston system for hydraulic mechanism of quick circuit breaker

Abstract

The low-abrasion piston system comprises a piston cylinder and a piston main body, the piston main body comprises a piston and a piston rod, the piston is provided with a dynamic seal, an end cover is fixedly connected to an opening of the piston cylinder, the piston rod penetrates through the end cover in a sealing mode, and the piston rod penetrates through the end cover in a sealing mode. Annular sealing grooves located in the two sides of the movable seal are formed in the piston, guide wear-resisting rings are installed in the annular sealing grooves, and a plurality of oil guide grooves penetrating in the axial direction are formed in the outer rings of the guide wear-resisting rings. Metal abrasion is replaced by guiding, meanwhile, the pressure bearing capacity is improved, a low-pressure oil port filtering device and a foreign matter containing cavity are arranged, the cleanliness of a system oil way is guaranteed, an end cover sealing structure is reasonably designed, positive and negative pressure two-way sealing is achieved, and the sealing effect is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of circuit breakers, and in particular to a low-wear piston system for a hydraulic mechanism of a fast circuit breaker. Background Art

[0002] High-voltage circuit breakers are critical components of power transmission and transformation equipment. The operating mechanism is the breaker's power source, and all circuit breaker movements are accomplished by the operating mechanism. Hydraulic disc spring operating mechanisms, as a type of circuit breaker operating mechanism, are widely used due to their superior performance, including high integration, compact size, high operating power, and stable performance. With the expansion of power systems and the rapid growth of grid loads, short-circuit current levels in power systems are increasing year by year. These significant short-circuit currents have become a serious threat to the safe operation of power systems. Therefore, rapidly interrupting fault currents places new demands on the speed and reliability of circuit breaker operating mechanisms.

[0003] For the hydraulic disc spring operating mechanism, since its energy transmission is achieved through high-pressure oil, a high-pressure sealing system is required during operation. However, failure of the high-pressure seal of the hydraulic disc spring mechanism leads to internal leakage, which causes the mechanism to be frequently pressurized. This type of problem is currently the main problem of the hydraulic disc spring operating mechanism, which has a certain impact on the reliable operation of power transmission and transformation equipment.

[0004] Based on the working principle of the hydraulic spring operating mechanism, whether the mechanism is in the open or closed state, as long as the hydraulic mechanism is in the energy storage state, when the seal of the energy storage piston is damaged and fails, it will cause internal leakage in the hydraulic mechanism. Further analysis found that the cause of the damage to the dynamic seal of the energy storage piston is the presence of metal impurities in the hydraulic mechanism system. As the hydraulic oil flows to the dynamic seal, the impurities are clamped in the dynamic seal area, scratching the dynamic seal during the reciprocating motion of the energy storage piston. Therefore, it is very necessary to change the sealing structure of the traditional energy storage piston system and provide a low-wear, zero-leakage, and highly reliable piston system. Summary of the Invention

[0005] In response to the deficiencies in the prior art, the present invention provides a low-wear piston system for a hydraulic mechanism of a fast circuit breaker. The piston system used in the hydraulic disc spring operating mechanism of a fast circuit breaker has good wear resistance, reliable sealing, and a long service life, and can effectively solve the problems in the background technology.

[0006] The present invention is achieved through the following technical solution, providing a low-wear piston system for a hydraulic mechanism of a fast circuit breaker, comprising a piston cylinder and a piston body, the piston body comprising a piston and a piston rod, the piston being equipped with a dynamic seal, an end cover being fixedly connected to the opening of the piston cylinder, the piston rod seal passing through the end cover, annular sealing grooves being formed on the piston on both sides of the dynamic seal, a guide wear-resistant ring being installed in the annular sealing groove, and the outer ring of the guide wear-resistant ring being provided with a plurality of oil guide grooves extending axially therethrough.

[0007] The dynamic seal in this solution acts as a piston seal. The guide wear-resistant ring provides precise guidance and support for the reciprocating piston and absorbs radial forces that may occur at any time, extending the service life of the piston cylinder. It also prevents metal contact between the piston and cylinder, reduces friction, improves the sealing effect, and avoids leakage. The oil guide groove design reduces the bearing pressure of the dynamic seal and protects the seal. When the system is over-pressurized, the oil guide groove cooperates with the piston cylinder to release system pressure and provide over-position protection. The oil guide groove runs axially through the piston and guides the axial movement of the piston, reducing its rotational motion.

[0008] As an optimization, a combined seal is installed between the end cap and the piston rod. The combined seal includes a slip ring, the inner ring of which has an annular groove, a star-shaped elastic rubber ring installed in the annular groove, and the outer ring of the slip ring is equipped with two O-shaped elastic rubber rings. In this solution, the star-shaped elastic rubber ring fits against the piston rod, the two O-shaped elastic rubber rings fit against the inner hole of the end cap, and the grooved slip ring is sandwiched between the star-shaped elastic rubber ring and the two O-shaped elastic rubber rings. When the piston body reciprocates, the elastic force of the elastic rubber rings on both sides can simultaneously isolate both gas and oil media, achieving a bidirectional seal with positive and negative pressures, and improving the sealing performance of the slip ring.

[0009] As an optimization, a dust ring is installed between the end cap and the piston rod, and the dust ring is located outside the combined seal. The dust ring in this solution prevents dust from entering the combined seal, thereby improving the service life and sealing performance of the combined seal.

[0010] As an optimization, the piston cylinder is arranged horizontally, with a foreign matter receiving cavity defined on the bottom surface of the inner wall of the piston cylinder. This cavity, when located at the very bottom of the hydraulic mechanism, can capture impurities such as metal particles generated during wear, preventing them from migrating through the oil circuit to other seals in the hydraulic mechanism, thereby preventing damage to sealing performance.

[0011] As an optimization, the piston cylinder is provided with a low-pressure oil port, which is equipped with a cap-shaped metal filter. The cap-shaped metal filter provided in this solution filters the oil and prevents metal particles and other impurities from entering the piston system when they appear in the oil path connecting to the low-pressure oil pressure.

[0012] As an optimization, the end cover is connected to the piston cylinder flange by bolts, thereby achieving a detachable fixing of the end cover.

[0013] As an optimization, the piston body is sprayed with tungsten carbide to improve wear resistance.

[0014] As an optimization, the end cover is provided with a raised portion inserted into the piston cylinder, and a sealing ring is installed between the outer ring of the raised portion and the piston cylinder, thereby improving the sealing performance of the end cover.

[0015] As an optimization, the guide wear-resistant ring is made of polytetrafluoroethylene with copper powder added, so that the guide wear-resistant ring has good wear resistance.

[0016] The beneficial effects of the present invention are: (1) Rationally design the structure and layout of the guide wear-resistant ring to achieve the supporting and guiding function of bidirectional reciprocating motion, replace metal wear with guidance, and improve the pressure bearing capacity at the same time.

[0017] (2) Rationally design the piston structure to improve the piston's wear resistance.

[0018] (3) Rationally design the structure of the piston cylinder, set up a low-pressure oil port filter device and a foreign matter receiving chamber to ensure the cleanliness of the system oil circuit.

[0019] (4) Rationally design the end cover sealing structure, with positive and negative pressure bidirectional sealing to improve the sealing effect.

[0020] (5) The clearance between the piston and the cylinder is rationally designed to reduce eccentric wear of the piston while effectively preventing impurities from entering the sealing area. Therefore, the present invention has the advantages of good wear resistance, reliable sealing, and long service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the end structure of the present invention; Figure 2 For the present invention Figure 1 Middle AA plane section view; Figure 3 is an enlarged cross-sectional view of the composite seal of the present invention; Figure 4 Schematic cross-sectional view of the guide wear-resistant ring of the present invention; Figure 5 For the present invention Figure 4 Enlarged view of middle part B; As shown in the figure: 1. Piston body, 2. Annular sealing groove, 3. Dynamic seal, 4. Guide wear-resistant ring, 5. Oil guide groove, 6. Piston cylinder, 7. Cap-shaped metal filter, 8. Sealing cylinder sleeve, 9. Foreign matter receiving chamber, 10. End cover, 11. Connecting bolt, 12. Star-shaped elastic rubber ring, 13. O-type elastic rubber ring, 14. Slip ring. DETAILED DESCRIPTION

[0022] In order to clearly illustrate the technical features of this solution, this solution is described below through specific implementation methods.

[0023] like Figures 1 to 5 As shown, a low-wear piston system for a hydraulic mechanism of a fast circuit breaker of the present invention includes a piston cylinder 6 and a piston body 1. The piston body 1 includes a piston and a piston rod. The piston body 1 is sprayed with tungsten carbide to improve wear resistance. The piston and the piston rod in this embodiment are integrally formed. An end cover 11 is fixedly connected to the opening of the piston cylinder 6. The end cover 11 in this embodiment is flange-connected to the piston cylinder 6 by bolts, thereby forming a closed piston chamber in the piston cylinder 6. In order to improve the sealing performance between the end cover 11 and the piston cylinder 6, a protrusion inserted into the piston cylinder 6 is provided on the end cover 11, and a sealing ring is installed between the outer ring of the protrusion and the piston cylinder 6.

[0024] The piston cylinder 6 is provided with a low-pressure oil port and a high-pressure oil port. The low-pressure oil port is provided in the rod cavity of the piston cylinder 6, and the high-pressure oil port is provided in the rodless cavity of the piston cylinder. A sealing cylinder sleeve 8 is installed on the low-pressure oil port, and a cap-shaped metal filter 7 is installed in the sealing cylinder sleeve 8. The filter screen 7 plays the role of filtering the oil. When foreign matter such as metal particles appears in the oil path connected to the low-pressure oil pressure, the filter screen prevents metal particles and other impurities from entering the piston system.

[0025] The piston rod seal passes through the end cover 11. In order to improve the sealing performance of the piston rod passing through the position, a combined seal is installed between the end cover 11 and the piston rod. An annular groove is opened on the inner hole of the end cover 11, and the combined seal is installed in the annular groove. Figure 3 As shown, the combined seal includes a slip ring 14 made of polytetrafluoroethylene. Its inner ring fits against the piston rod and is defined by an annular groove. A star-shaped elastic rubber ring 12 is mounted within the groove. Two O-rings 13 are mounted on the outer ring of the slip ring. The star-shaped elastic rubber ring fits against the piston rod, while the two O-rings fit within the inner bore of the end cap. The grooved slip ring is sandwiched between the star-shaped elastic rubber ring and the two O-rings. As the piston reciprocates, the elastic forces of the two elastic rings simultaneously isolate both gas and oil, achieving a bidirectional seal with both positive and negative pressures and improving the sealing performance of the slip ring.

[0026] In order to prevent dust from affecting the sealing effect of the combined seal, a dust ring is installed between the end cover 11 and the piston rod, and the dust ring is located on the outside of the combined seal.

[0027] The piston is equipped with a dynamic seal 3. This is a conventional seal typically implemented using a sealing ring, which provides a seal during piston movement. The piston is provided with annular sealing grooves 2 on either side of the dynamic seal 3. Guide wear-resistant rings 4 are mounted within these grooves. These guide wear-resistant rings 4 are made of polytetrafluoroethylene (PTFE) with copper powder added.

[0028] The outer ring of the guide wear-resistant ring 4 is in contact with the inner wall of the piston cylinder 6. Figure 4 、 5 As shown, the outer ring of the guide wear-resistant ring 4 is provided with a plurality of oil guide grooves 5 that penetrate axially. In this embodiment, two oil guide grooves 5 are provided and are evenly distributed along the circumference. The guide wear-resistant ring has a precise guiding and supporting function for the reciprocating piston, and can absorb the radial force generated at any time, thereby extending the service life of the piston cylinder. At the same time, it can prevent metal contact between the piston and the piston cylinder, reduce friction, improve the sealing effect, and avoid leakage. The design of the oil guide groove can reduce the bearing pressure of the dynamic seal and protect the seal. When the system is over-pressured, the oil guide groove cooperates with the piston cylinder to realize the system pressure release and play the role of over-position protection. The oil guide groove penetrates axially and can also guide the axial movement of the piston and reduce the rotational movement of the piston.

[0029] The piston cylinder 6 is arranged horizontally, and a foreign matter receiving chamber 9 is defined on the bottom surface of the inner wall of the piston cylinder 6. The foreign matter receiving chamber 9 has a grid-like structure, consisting of an array of multiple rectangular slots. When located at the bottom of the hydraulic mechanism, this system can capture impurities such as metal particles generated during wear, preventing them from flowing through the oil circuit to other sealing locations in the hydraulic mechanism and impairing sealing performance.

[0030] Of course, the above description is not limited to the above examples. Technical features not described in the present invention can be achieved by or by adopting existing technologies, which will not be described here. The above embodiments and drawings are only used to illustrate the technical solutions of the present invention and are not limitations of the present invention. The present invention is described in detail with reference to the preferred implementation methods. Ordinary technicians in this field should understand that changes, modifications, additions or substitutions made by ordinary technicians in this technical field within the essential scope of the present invention do not depart from the purpose of the present invention and should also fall within the scope of protection of the claims of the present invention.

Claims

1. A low-wear piston system for a hydraulic mechanism of a fast circuit breaker, comprising a piston cylinder (6) and a piston body (1), wherein the piston body (1) comprises a piston and a piston rod, and a dynamic seal (3) is mounted on the piston, characterized in that: An end cover (11) is fixedly connected to the opening of the piston cylinder (6), and the piston rod seal passes through the end cover (11). The piston is provided with an annular sealing groove (2) located on both sides of the dynamic seal (3). A guide wear-resistant ring (4) is installed in the annular sealing groove (2). The outer ring of the guide wear-resistant ring (4) is provided with a plurality of oil guide grooves (5) penetrating along the axial direction.

2. A low-wear piston system for a hydraulic mechanism of a fast circuit breaker according to claim 1, characterized in that: A combined seal is installed between the end cover (11) and the piston rod, and the combined seal includes a slip ring (14). The inner ring of the slip ring (14) is provided with an annular groove, a star-shaped elastic rubber ring (12) is installed in the annular groove, and the outer ring of the slip ring (14) is provided with two O-type elastic rubber rings (13).

3. The low-wear piston system for a hydraulic mechanism of a fast circuit breaker according to claim 1, characterized in that: A dust ring is installed between the end cover (11) and the piston rod, and the dust ring is located outside the combined seal.

4. The low-wear piston system for a hydraulic mechanism of a fast circuit breaker according to claim 1, characterized in that: The piston cylinder (6) is arranged transversely, and a foreign matter receiving cavity (9) is formed on the bottom surface of the inner wall of the piston cylinder (6).

5. The low-wear piston system for a hydraulic mechanism of a fast circuit breaker according to claim 1, characterized in that: A low-pressure oil port is provided on the piston cylinder (6), and a cap-shaped metal filter (7) is installed in the low-pressure oil port.

6. The low-wear piston system for a hydraulic mechanism of a fast circuit breaker according to claim 1, characterized in that: The end cover (11) is flange-connected to the piston cylinder (6) via bolts.

7. The low-wear piston system for a fast circuit breaker hydraulic mechanism according to claim 1, characterized in that: The piston body (1) is sprayed with tungsten carbide.

8. The low-wear piston system for a hydraulic mechanism of a fast circuit breaker according to claim 1, characterized in that: The end cover (11) is provided with a raised portion inserted into the piston cylinder (6), and a sealing ring is installed between the outer ring of the raised portion and the piston cylinder (6).

9. The low-wear piston system for a hydraulic mechanism of a fast circuit breaker according to claim 1, characterized in that: The material of the guide wear-resistant ring (4) is polytetrafluoroethylene added with copper powder.

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