High-pressure sealing structure for sealing rotating shaft of high-pressure gear pump

Abstract

The utility model relates to a sealing structure, in particular to a high-pressure sealing structure for sealing a rotating shaft of a high-pressure gear pump. The sealing structure is structurally arranged on a rotating shaft (1) in the high-pressure gear pump, a cover body (4) is arranged on the outer side of the end portion of the rotating shaft (1), a check ring (2), a low-pressure oil seal (3-1) and a high-pressure oil seal (3-2) are sequentially arranged at the position of an oil seal between the rotating shaft (1) and the cover body (4) from outside to inside, and the high-pressure oil seal (3-2) and the low-pressure oil seal (3-1) are rotating lip-shaped sealing pieces. According to the high-pressure sealing structure for sealing the rotating shaft of the high-pressure gear pump, the low-pressure oil seal is arranged on the outer side of the high-pressure oil seal, so that the sealing effect is greatly improved on the premise that lubrication is guaranteed.

Description

Technical Field

[0001] The utility model relates to a sealing structure, in particular to a high-pressure sealing structure used for sealing a rotating shaft of a high-pressure gear pump. Background Art

[0002] As we all know, the sealing principle of lip seals (commonly known as oil seals) for rotating shafts is: under the pressure of the sealing medium (hydraulic oil), a small amount of medium enters between the lip and the rotating shaft to form a sealing fluid oil film, which lubricates the lip on the one hand and takes away the heat generated by the sealing friction between the lip and the rotating shaft on the other hand, thereby achieving the purpose of increasing the life of the lip.

[0003] However, in the actual transmission process, although a small amount of lubricating oil precipitated from the lubricating oil film does not affect the use of the product, in some scenarios with stringent sealing requirements (such as dust, ultra-clean industrial workshops, etc.), a small amount of hydraulic oil precipitated cannot meet the use requirements. Especially for hydraulic devices used in the electric market today, the requirements for sealing are getting higher and higher, and the existing sealing structure can no longer meet the needs of use.

[0004] As attached Figure 1 As shown, the structure of the prior art solution includes a rotating shaft 1, a rotating sealing assembly 3 (oil seal) and a cover body 4. The cover body is provided with an assembly hole, and an oil seal is provided between the cover body and the rotating shaft to play a sealing role, that is, a group of oil seals are used to achieve the sealing effect, but such a structural design cannot overcome the aforementioned problems. Utility Model Content

[0005] In order to solve the problems of the prior art, the utility model provides a high-pressure sealing structure for sealing a rotating shaft of a high-pressure gear pump, which greatly improves the sealing effect while ensuring lubrication by providing a low-pressure oil seal on the outside of the high-pressure oil seal.

[0006] The technical solution adopted by the utility model is as follows:

[0007] A high-pressure sealing structure for sealing a rotating shaft of a high-pressure gear pump, comprising a rotating shaft (1) arranged in the high-pressure gear pump, a cover body (4) arranged outside the end of the rotating shaft (1), a retaining ring (2), a low-pressure oil seal (3-1) and a high-pressure oil seal (3-2) arranged in sequence from outside to inside at the oil seal between the rotating shaft (1) and the cover body (4), the high-pressure oil seal (3-2) and the low-pressure oil seal (3-1) both being rotating lip seals.

[0008] Preferably, the low-pressure oil seal (3-1) comprises a low-pressure inner steel frame (3-1-1), the low-pressure inner steel frame (3-1-1) externally covers a low-pressure oil seal body, the low-pressure oil seal body is provided with a low-pressure spring groove (3-1-2), a low-pressure spring (3-1-3) is arranged in the low-pressure spring groove (3-1-2), and the low-pressure oil seal body further comprises a low-pressure lip inner edge (3-1-4), a low-pressure lip (3-1-5), and a low-pressure lip outer edge (3-1-6). 1-6), a low-pressure waist (3-1-7) and a dustproof lip (3-1-8), wherein the low-pressure waist (3-1-7) is designed to be parallel inside and outside, the inner edge (3-1-4) of the low-pressure lip is arranged at an acute angle to the axis of the rotating shaft, the low-pressure lip (3-1-5) and the rotating shaft (1) are designed to be in linear contact, the angle between the inner edge (3-1-4) of the low-pressure lip and the outer edge (3-1-6) of the low-pressure lip is 80° to 110°, and the dustproof lip (3-1-8) is a square dustproof lip.

[0009] Preferably, the high-pressure oil seal (3-2) is provided with a high-pressure inner steel skeleton (3-2-1), the high-pressure inner steel skeleton (3-2-1) externally covers a high-pressure oil seal body, the high-pressure oil seal body is respectively provided with a guide step (3-2-2), a high-pressure spring groove (3-2-3), a high-pressure lip inner edge (3-2-5), a high-pressure lip (3-2-6), a high-pressure lip outer edge (3-2-7) and a high-pressure waist (3-2-8), a high-pressure spring (3-2-4) is arranged in the high-pressure spring groove (3-2-3), the high-pressure waist (3-2-8) is designed with inner and outer sides parallel, the high-pressure lip inner edge (3-2-5) is arranged at an acute angle to the rotation axis, the high-pressure lip (3-2-6) and the rotation axis (1) are designed to be in linear contact, and the angle between the high-pressure lip inner edge (3-2-5) and the high-pressure lip outer edge (3-2-7) is 80° to 110°.

[0010] The beneficial effects brought by the technical solution provided by the utility model are:

[0011] 1. The high-pressure gear pump encapsulated by the high-pressure sealing structure of the utility model has achieved a zero leakage effect through experimental verification, solving the technical problems existing in the existing solutions.

[0012] 2. Compared with the existing commonly used technical solutions, the lip structure of the high-pressure sealing structure of the utility model has excellent self-lubricating properties, which can significantly improve the friction resistance of the lip and the service life of the product.

[0013] 3. The high-pressure sealing structure of the utility model is provided with a three-lip structure (high-pressure lip, low-pressure lip, and dustproof lip), which can adapt to various harsh high-pressure, low-pressure and dustproof working conditions.

[0014] 4. The high-pressure sealing structure of the utility model can achieve environmental protection and green design goals.

[0015] 5. The high-pressure sealing structure of the utility model has the characteristic of maintenance-free, which greatly reduces the wear of the lip, improves the service life of the hydraulic pump, and can ensure the stability and reliability of the working system of the hydraulic equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0017] Figure 1 It is a structural schematic diagram of a high-pressure gear pump rotating shaft sealing structure in the prior art;

[0018] Figure 2 This is a structural schematic diagram of a high-pressure sealing structure for sealing a rotating shaft of a high-pressure gear pump according to the utility model;

[0019] Figure 3 It is a partial structural schematic diagram of a low-pressure oil seal of a high-pressure sealing structure for sealing a rotating shaft of a high-pressure gear pump according to the utility model;

[0020] Figure 4 The utility model is a partial structural schematic diagram of a high-pressure oil seal of a high-pressure sealing structure for sealing a rotating shaft of a high-pressure gear pump. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the present invention more clear, the implementation mode of the present invention will be further described in detail below with reference to the accompanying drawings. Example 1

[0022] As attached Figure 2-4 As shown, the technical solution of this embodiment includes a rotating shaft 1, a retaining ring 2, a high-pressure sealing assembly, and a cover body 4. The high-pressure sealing assembly is composed of a high-pressure oil seal 3-2 and a low-pressure oil seal 3-1. The high-pressure sealing device is a device in which two independently configured rotating lip seals are placed in an oil seal hole and fixed with a retaining ring, a low-pressure oil seal 3-1 is placed on the side close to the retaining ring 2, and a high-pressure oil seal 3-2 is placed on the side away from the retaining ring 2.

[0023] The low-pressure oil seal 3-1 includes a low-pressure inner steel frame 3-1-1, the low-pressure inner steel frame 3-1-1 is externally covered with a low-pressure steel frame body, and the low-pressure steel frame body is provided with a low-pressure spring groove 3-1-2, a low-pressure spring 3-1-3, a low-pressure lip inner edge 3-1-4, a low-pressure lip 3-1-5, a low-pressure lip outer edge 3-1-6, a low-pressure waist 3-1-7, and a dustproof lip 3-1-8. The low-pressure waist 3-1-7 is designed with parallel inner and outer sides, and the inner edge 3-1-4 of the low-pressure lip is arranged at an acute angle with the rotating shaft axis, the angle is generally 10°~80°, and the optimal angle is set to 30°~60°; in order to improve the pressure resistance and service life of the lip, the contact part between the low-pressure lip 3-1-5 and the rotating shaft 1 is a linear contact design, and the angle between the inner edge 3-1-4 of the low-pressure lip and the outer edge 3-1-6 of the low-pressure lip is generally 80°~110°, and the optimal angle is 90°~100°; the low-pressure oil seal 3-1 is also provided with a square dustproof lip 3-1-8 for outer dustproof sealing.

[0024] The high-pressure oil seal 3-2 includes a high-pressure inner steel skeleton 3-2-1 which externally covers the high-pressure oil seal body. The high-pressure oil seal body is provided with a guide step 3-2-2, a high-pressure spring groove 3-2-3, a high-pressure spring 3-2-4, an inner edge 3-2-5 of a high-pressure lip, a high-pressure lip 3-2-6, an outer edge 3-2-7 of a high-pressure lip, and a high-pressure waist 3-2-8. The high-pressure waist 3-2-8 is designed to be parallel inside and outside. The inner edge 3-2-5 of the high-pressure lip is arranged at an acute angle to the axis of the rotating shaft, and the angle is generally 10° to 80°, and the optimal angle is set to 30° to 60°. In order to improve the pressure resistance and service life of the lip, the contact surface of the high-pressure lip 3-2-6 and the rotating shaft 1 is a linear contact design, and the angle between the inner edge 3-2-5 of the high-pressure lip and the outer edge 3-2-7 of the high-pressure lip is generally 80° to 110°, and the optimal angle is 90° to 100°.

[0025] The specific working principle is as follows: the inner high-pressure oil seal 3-2 is used to withstand the high-pressure medium inside the gear pump. The high-pressure lip 3-2-6 is tightly wrapped around the rotating shaft 1 under the combined effect of the interference fit of the lip itself and the high-pressure spring 3-2-4. As the rotating shaft 1 rotates, the sealed hydraulic oil enters the position of the high-pressure lip 3-2-6. Under the action of the hydraulic oil pressure, the outer edge 3-2-7 of the high-pressure lip will be further deformed and wrapped around the rotating shaft 1. At this time, due to the rotation of the rotating shaft 1, the sealed high-pressure oil will form an oil film between the high-pressure lip 3-2-6 and the rotating shaft 1. The formation of the oil film ensures that the high-pressure lip 3-2-6 is well lubricated on the one hand, and on the other hand, it will take away the heat generated by friction to ensure that the sealing lip does not age quickly due to high temperature.

[0026] During operation, a small amount of lubricating oil will normally be precipitated and reach the position 3-2-7 outside the high-pressure lip. The high-pressure sealing device of this design is provided with a low-pressure oil seal 3-1 on the outside of the high-pressure oil seal 3-2. The small amount of lubricating oil precipitated at the position 3-2-7 outside the high-pressure lip will be sealed in the space between the low-pressure lips 3-1-5 as a lubricant for the low-pressure lips 3-1-5. Since the hydraulic oil leaked here is very small, the pressure at the low-pressure lip 3-1-5 will be very low. The low-pressure lip 3-1-5 can seal the hydraulic pressure here in the space by its own interference fit. As the hydraulic oil accumulated here increases, the pressure will gradually increase. When the gear pump runs at high speed, a local vacuum negative pressure will be formed at the high-pressure lip 3-2-6. At this time, the accumulated hydraulic oil will be pushed back into the oil pump to achieve a zero leakage effect. The low-pressure oil seal 3-1 is also provided with a square dustproof lip to seal the external dust from entering the sealing component.

[0027] The material used for the high-pressure sealing component is rubber, which can also be replaced by nylon, polytetrafluoroethylene and other sealing materials. The protection rights will not be lost due to the change of materials.

[0028] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A high-pressure sealing structure for sealing a rotating shaft of a high-pressure gear pump, the structure being arranged on a rotating shaft (1) in the high-pressure gear pump, wherein a cover (4) is arranged outside an end of the rotating shaft (1), and the structure is characterized in that: A retaining ring (2), a low-pressure oil seal (3-1) and a high-pressure oil seal (3-2) are arranged in order from outside to inside at the oil seal between the rotating shaft (1) and the cover body (4); the high-pressure oil seal (3-2) and the low-pressure oil seal (3-1) are both rotating lip seals; the low-pressure oil seal (3-1) comprises a low-pressure inner steel frame (3-1-1); the low-pressure inner steel frame (3-1-1) externally covers a low-pressure oil seal body; a low-pressure spring groove (3-1-2) is arranged on the low-pressure oil seal body; a low-pressure spring (3-1-3) is arranged in the low-pressure spring groove (3-1-2); the low-pressure oil seal The main body also comprises a low-pressure lip inner edge (3-1-4), a low-pressure lip (3-1-5), a low-pressure lip outer edge (3-1-6), a low-pressure waist (3-1-7) and a dustproof lip (3-1-8), wherein the low-pressure waist (3-1-7) is designed to be parallel inside and outside, the low-pressure lip inner edge (3-1-4) is arranged at an acute angle to the rotation axis, the low-pressure lip (3-1-5) and the rotation axis (1) are designed to be in linear contact, the angle between the low-pressure lip inner edge (3-1-4) and the low-pressure lip outer edge (3-1-6) is 80° to 110°, and the dustproof lip (3-1-8) is a square dustproof lip.

2. A high-pressure sealing structure for sealing a rotating shaft of a high-pressure gear pump according to claim 1, characterized in that: The angle between the inner edge (3-1-4) of the low-pressure lip and the rotation axis is 10° to 80°.

3. A high-pressure sealing structure for sealing a rotating shaft of a high-pressure gear pump according to claim 2, characterized in that: The angle between the inner edge (3-1-4) of the low-pressure lip and the rotation axis is 30° to 60°.

4. A high-pressure sealing structure for sealing a rotating shaft of a high-pressure gear pump according to claim 1, characterized in that: The angle between the inner edge (3-1-4) of the low-pressure lip and the outer edge (3-1-6) of the low-pressure lip is 90° to 100°.

5. A high-pressure sealing structure for sealing a rotating shaft of a high-pressure gear pump according to claim 1, characterized in that: The high-pressure oil seal (3-2) is provided with a high-pressure inner steel frame (3-2-1), the high-pressure inner steel frame (3-2-1) externally covers a high-pressure oil seal body, and the high-pressure oil seal body is respectively provided with a guide step (3-2-2), a high-pressure spring groove (3-2-3), a high-pressure lip inner edge (3-2-5), a high-pressure lip (3-2-6), a high-pressure lip outer edge (3-2-7) and a high-pressure waist (3-2-8), a high-pressure spring (3-2-4) is arranged in the high-pressure spring groove (3-2-3), the high-pressure waist (3-2-8) is designed with inner and outer sides parallel, the high-pressure lip inner edge (3-2-5) is arranged at an acute angle with the rotation axis, the high-pressure lip (3-2-6) and the rotation axis (1) are designed to be in linear contact, and the angle between the high-pressure lip inner edge (3-2-5) and the high-pressure lip outer edge (3-2-7) is 80° to 110°.

6. A high-pressure sealing structure for sealing a rotating shaft of a high-pressure gear pump according to claim 5, characterized in that: The angle between the inner edge (3-2-5) of the high-pressure lip and the rotation axis is 10° to 80°.

7. A high-pressure sealing structure for sealing a rotating shaft of a high-pressure gear pump according to claim 6, characterized in that: The angle between the inner edge (3-2-5) of the high-pressure lip and the rotation axis is 30° to 60°.

8. A high-pressure sealing structure for sealing a rotating shaft of a high-pressure gear pump according to claim 5, characterized in that: The angle between the inner edge (3-2-5) of the high-pressure lip and the outer edge (3-2-7) of the high-pressure lip is 90° to 100°.

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