Sealing structure for improving sealing performance of shaft tail of hydraulic pump

Abstract

The utility model discloses a sealing structure for improving the sealing performance of a shaft tail of a hydraulic pump. The sealing structure comprises a shell, a main shaft arranged in the shell, a rear cover arranged on the shell, a static ring arranged on the main shaft in a sleeving mode, a movable ring and a leather cup. An oil seal spring is correspondingly arranged on the leather cup; a gasket and a wave ring are correspondingly arranged on the end face of the leather cup. The leather cup corresponds to the movable ring; a retaining bracket is arranged on the main shaft; and the leather cup is positioned between the movable ring and the gasket. The sealing structure is improved on the basis of an original structure, a sealing mode of installing a sealing ring on a moving ring of the original structure is canceled, the packing cup is sealed with the main shaft through the oil seal spring, meanwhile, the gasket structure is additionally arranged to be attached to the back face of the packing cup, it is guaranteed that the wavy ring is evenly stressed on the gasket, and therefore the packing cup is tightly attached to the moving ring, and the sealing purpose is achieved; the sealing structure has the advantages of being better in sealing performance and more reliable.

Description

Technical Field

[0001] The utility model relates to the technical field of hydraulics, in particular to a sealing structure for improving the sealing performance of a hydraulic pump shaft tail. Background Art

[0002] Hydraulic plunger pumps are widely used in aerospace and other fields due to their high pressure, large flow, high efficiency, and good dynamic characteristics. They are the power source of aircraft hydraulic systems.

[0003] During the operation of the hydraulic plunger pump, the rotor plunger moves back and forth, forming high and low pressure areas. During the operation, the hydraulic oil enters the pump chamber through the gap between the rotor plunger to achieve the purpose of lubrication and heat dissipation. At the same time, it also causes the housing cavity of the hydraulic plunger pump to be filled with hydraulic oil and the pressure is relatively high. In order to ensure the sealing performance of the hydraulic plunger pump and make the system work normally, the pump cavity of the hydraulic plunger pump is sealed by combining the shaft tail seal and the static seal to ensure that the oil in the housing cavity does not leak.

[0004] The tail seal of a hydraulic piston pump is a key component, ensuring fluid leakage from the system housing and maintaining aircraft flight safety. Improving the sealing performance of the tail seal effectively prevents fluid leakage from the hydraulic piston pump and is a key approach to improving aircraft hydraulic system safety.

[0005] In the existing shaft tail sealing structure, the metal plane sealing mechanism at the shaft tail of the hydraulic plunger pump consists of two parts: a static ring and a dynamic ring. The static ring is stationary, while the dynamic ring rotates with the main shaft. Under the action of the elastic force of the wave ring, the working plane of the dynamic ring is tightly fitted with the working plane of the static ring to ensure sealing. The sealing ring and the main shaft cooperate to seal the oil in the pump chamber. When the hydraulic plunger pump is operating, the oil film between the working planes of the dynamic and static rings acts as a lubricant. During operation, a very small amount of oil leaks out of the hydraulic plunger pump through the oil leakage pipe joint. When the hydraulic plunger pump is operating, the shaft tail is exposed to high temperature and immersed in hydraulic oil. As the hydraulic plunger pump's operating time increases, the sealing ring will expand and deform under the immersion of high-temperature oil, causing the dynamic ring to shift. As a result, the dynamic ring and the static ring cannot be effectively fitted together, and a small gap will appear, causing the hydraulic oil in the pump chamber to leak, thereby reducing the sealing performance of the shaft tail and causing shaft tail oil leakage.

[0006] The expansion and deformation of the sealing ring will increase the friction between it and the main shaft, making it difficult to disassemble during maintenance, and its maintainability and assembly performance are poor.

[0007] At the same time, the existing static ring and dynamic ring pairing materials are made of copper alloy and alloy steel. When working at high speed for a long time, the mating surface is prone to copper sticking, which reduces the roughness of the sealing surface and causes oil leakage at the shaft tail. Utility Model Content

[0008] The purpose of the utility model is to provide a sealing structure for improving the sealing performance of a hydraulic pump shaft tail, and the utility model has the advantages of better sealing performance and greater reliability.

[0009] The technical solution of the utility model is: a sealing structure for improving the sealing performance of the tail of a hydraulic pump shaft, comprising a housing, a main shaft arranged in the housing, a rear cover arranged on the housing, a static ring, a dynamic ring and a leather cup sleeved on the main shaft; an oil seal spring is correspondingly provided on the leather cup; a gasket and a wave ring are correspondingly provided at the end face of the leather cup; the leather cup corresponds to the dynamic ring; a retaining bracket is provided on the main shaft; and the leather cup is located between the dynamic ring and the gasket.

[0010] In the aforementioned sealing structure for improving the sealing performance of the hydraulic pump shaft tail, a sealing ring a and a sealing ring b are provided between the static ring and the rear cover respectively.

[0011] In the aforementioned sealing structure for improving the sealing performance of the hydraulic pump shaft tail, the retaining bracket cooperates with the main shaft through a rectangular spline structure; the wave ring, gasket, leather cup, oil seal spring and dynamic ring are all located in the retaining bracket.

[0012] Compared with the prior art, the present invention improves upon the original structure by eliminating the sealing method of the sealing ring on the dynamic ring of the original structure and adopting a leather cup oil seal spring to seal the main shaft. At the same time, a gasket structure is added to fit the back of the leather cup to ensure that the wave ring exerts uniform force on the gasket, thereby making the leather cup and the dynamic ring fit tightly to achieve the purpose of sealing.

[0013] Therefore, the utility model has the advantages of better sealing and greater reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural diagram of the present utility model.

[0015] Markings in the accompanying drawings: 1-rear cover, 2-sealing ring a, 3-sealing ring b, 4-static ring, 5-dynamic ring, 6-main shaft, 7-oil seal spring, 8-leather cup, 9-washer, 10-wave ring, 11-retaining bracket. DETAILED DESCRIPTION

[0016] The present invention will be further described below with reference to the accompanying drawings and examples, but they are not intended to limit the present invention.

[0017] Embodiment. A sealing structure for improving the sealing performance of the hydraulic pump shaft tail, such as Figure 1As shown, it includes a shell, a main shaft 6 arranged in the shell, a back cover 1 arranged on the shell, a static ring 4, a dynamic ring 5 and a leather cup 8 sleeved on the main shaft 6; an oil seal spring 7 is correspondingly provided on the leather cup 8; a gasket 9 and a wave ring 10 are correspondingly provided at the end face of the leather cup 8; the leather cup 8 corresponds to the dynamic ring 5; a retaining bracket 11 is provided on the main shaft 6; the leather cup 8 is located between the dynamic ring 5 and the gasket 9.

[0018] A sealing ring a2 and a sealing ring b3 are provided between the stationary ring 4 and the rear cover 1 , respectively.

[0019] The retaining bracket 11 cooperates with the main shaft 6 through a rectangular spline structure; the wave ring 10, the washer 9, the leather cup 8, the oil seal spring 7 and the dynamic ring 5 are all located in the retaining bracket 11.

[0020] The integrated design of the dynamic ring 5 optimizes the internal sealing groove structure of the dynamic ring 5 and improves assembly and maintainability. When the static ring 4 and the dynamic ring 5 are working, the wave ring 10 supports the dynamic ring, provides preload and compensation force, and makes the dynamic ring 5 fit tightly with the static ring 4.

[0021] The friction surfaces of the static ring 4 and the dynamic ring 5 that fit each other slide relative to each other during operation and form a sealing end surface to prevent leakage of the oil medium in the pump cavity of the hydraulic plunger pump. It is the main sealing part.

[0022] The static ring 4 is made of carbide steel material, which effectively improves the wear resistance of the hydraulic plunger pump in a high temperature environment. The dynamic ring 5 is made of graphite material, which has corrosion resistance and good self-lubrication. It has very good resistance to friction and wear in the mechanical seal structure environment of the hydraulic plunger pump, and can effectively improve the sealing performance of the hydraulic plunger pump shaft tail. At the same time, it has good adaptability. According to the interface form and internal space of the peripheral hydraulic plunger pump interface parts, the structural dimensions of the relevant parts can be adjusted to realize functions such as in-situ replacement.

[0023] Working principle:

[0024] When the hydraulic plunger pump is working, the rear cover 1 and the static ring 4 are sealed by the sealing ring a2 and the sealing ring b3, the leather cup 8 is assembled with the main shaft 6, and the shaft tail structure seals the leather cup 8 and the main shaft 6 through the tightening force of the oil seal spring 7;

[0025] The gasket 9 is pressed tightly against the end face of the leather cup 8 under the pre-tightening force of the wave ring 10, so that the leather cup 8 and the dynamic ring 5 are closely matched to achieve sealing;

[0026] The retaining bracket 11 cooperates with the main shaft 6 through a rectangular spline structure. During operation, the retaining bracket 11 drives the wave ring 10, leather cup 8, oil seal spring 7, gasket 9, dynamic ring 5 and other parts to rotate with the main shaft 6, and the static ring 4 remains stationary. The pre-tightening force of the wave ring 10 makes the dynamic ring 5 fit with the static ring 4, thereby achieving sealing of the pump chamber oil.

[0027] The leather cup 8 is used to prevent the hydraulic oil in the hydraulic plunger pump chamber from leaking from the gap between the driven ring 5 and the main shaft 6. The oil seal spring 7 is used to increase the sealing between the leather cup 8 and the main shaft 6.

[0028] The leather cup 8 is located between the gasket 9 and the rotating ring 5, providing both radial and axial sealing. There is a certain amount of interference between the leather cup 8 and the oil seal spring 7. When the main shaft 6 is not rotating, the interference fit provides a radial seal. When the main shaft is rotating, the normal pressure generated by the radial tension of the oil seal spring 7 presses the leather cup 8 against the main shaft 6, providing a radial seal. This effectively improves the sealing performance of the shaft tail and solves the problem of oil leakage caused by the expansion and deformation of the seal ring when immersed in high-temperature oil, which can lead to an ineffective fit between the rotating ring 5 and the static ring 4.

[0029] The gasket 9 serves as a supporting structure, and the axial sealing is mainly transmitted to the gasket 9 by the elastic force of the wave ring 10. The gasket 9 generates a left axial force to make the leather cup 8 and the end face of the dynamic ring 5 evenly stressed. After the shaft tail sealing structure is assembled, the gasket 9 relies on the elastic force of the wave ring 10 to press the leather cup 8 to the end face of the dynamic ring 5, thereby playing a sealing role.

Claims

1. A sealing structure for improving the sealing performance of a hydraulic pump shaft tail, characterized by: The invention comprises a housing, a main shaft (6) arranged in the housing, a rear cover (1) arranged on the housing, a stationary ring (4) sleeved on the main shaft (6), a dynamic ring (5) and a leather cup (8); an oil seal spring (7) is correspondingly provided on the leather cup (8); a gasket (9) and a wave ring (10) are correspondingly provided at the end surface of the leather cup (8); the leather cup (8) corresponds to the dynamic ring (5); a retaining bracket (11) is provided on the main shaft (6); and the leather cup (8) is located between the dynamic ring (5) and the gasket (9).

2. A sealing structure for improving the sealing performance of a hydraulic pump shaft tail according to claim 1, characterized in that: A sealing ring a (2) and a sealing ring b (3) are correspondingly provided between the stationary ring (4) and the rear cover (1).

3. The sealing structure for improving the sealing performance of the hydraulic pump shaft tail according to claim 1, characterized in that: The retaining bracket (11) is matched with the main shaft (6) through a rectangular spline structure; the wave ring (10), the washer (9), the leather cup (8), the oil seal spring (7) and the dynamic ring (5) are all located in the retaining bracket (11).

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