Air cushion sealing element and sealing structure thereof

Abstract

The utility model discloses an air cushion sealing piece and a sealing structure thereof. The air cushion sealing piece comprises a sealing inner lip, a vent groove is formed in the sealing contact face of the sealing inner lip and penetrates to the near-air end of the sealing inner lip, a pump pressure groove communicated with the vent groove is formed in the sealing contact face of the sealing inner lip, and the pump pressure groove is arranged in the circumferential direction and is of a wedge-shaped structure. The sealing structure comprises a rotating component and further comprises the air cushion sealing piece, and the sealing contact face of the sealing inner lip is in sealing fit with the rotating component. The sealing element has the beneficial effects that based on the pneumatic principle of the wedge-shaped pump pressure groove, gas generates a wedge-shaped effect at the pump pressure groove during high-speed rotation, so that an air cushion is formed between a rotating component and the sealing inner lip, the friction loss between the sealing element and the rotating component is reduced, and the long-term dynamic sealing effect of the sealing element under the high-speed working condition is ensured.

Description

Technical Field

[0001] This application belongs to the field of rotary sealing technology, specifically relating to an air cushion seal and its sealing structure. Background Technology

[0002] Seals, also known as oil seals, are materials or parts used to prevent fluid or solid particles from leaking between adjacent mating surfaces and to prevent external impurities such as dust and moisture from entering the interior of machinery and equipment. They are widely used in the lubrication of shafts. In traditional seals, due to the high-speed rotation of the shaft, contact between the shaft and the seal inevitably causes wear, which cannot guarantee a long-term dynamic sealing effect, affecting service life and sealing quality. Utility Model Content

[0003] The purpose of this application is to provide an air cushion seal and its sealing structure, which solves the problem of long-term dynamic sealing of the seal under high-speed rotation conditions.

[0004] The objective of this application is achieved through the following technical solution:

[0005] An air cushion seal includes a sealing inner lip, the sealing contact surface of the sealing inner lip is provided with a vent groove, the vent groove extends to the near-air end of the sealing inner lip, the sealing contact surface of the sealing inner lip is provided with a pump pressure groove communicating with the vent groove, the pump pressure groove is arranged circumferentially and has a wedge-shaped structure.

[0006] Furthermore, it also includes a fixed outer frame and an elastic waist, with the fixed outer frame connected to the outer end of the elastic waist and the inner end of the elastic waist connected to the sealing inner lip.

[0007] Furthermore, the fixed outer frame has an L-shaped cross-section structure. One end of the L-shaped fixed outer frame is connected to the elastic waist, and the other end of the L-shaped fixed outer frame faces the same side as the elastic waist. The elastic waist is arranged at an angle, and the sealing inner lip is arranged in the same direction as the other end of the L-shaped fixed outer frame.

[0008] Furthermore, the fixed outer frame includes an axial section and a radial section. The near end of the axial section is connected to the outer end of the radial section, and the inner end of the radial section is connected to the elastic waist. An L-shaped support frame is embedded in both the axial and radial sections, and a fixed flange is provided on the fixed contact surface of the axial section.

[0009] Furthermore, the elastic waist includes an inclined waist section, the outer end of which is connected to the fixed outer frame via a near-air angle head, and the inner end of which is connected to the sealing inner lip via a near-liquid bend head.

[0010] Furthermore, the ventilation groove is provided in several places, and the ventilation grooves are arranged at intervals along the circumferential direction on the inner lip of the seal. Each ventilation groove is connected to several pump pressure grooves.

[0011] Furthermore, the pump pressure groove includes a main pump pressure groove and an auxiliary pump pressure groove. The groove length of the main pump pressure groove is greater than that of the auxiliary pump pressure groove. The main pump pressure groove is arranged in the forward rotation direction of the sealing inner lip, and the auxiliary pump pressure groove is arranged in the reverse rotation direction of the sealing inner lip.

[0012] Furthermore, the pump groove includes a flat bottom edge, an inclined side edge, and an inclined top edge forming a wedge-shaped structure. The flat bottom edge is parallel to the circumferential direction of the inner sealing lip. An angle α is formed between the inclined side edge and the flat bottom edge, and an angle β is formed between the inclined top edge and the flat bottom edge. α is 10° to 15°, β is 2° to 10°, and the groove depth of the pump groove is h, where h is 0.01mm to 0.05mm.

[0013] A sealing structure for an air cushion seal includes a rotating member and the aforementioned air cushion seal. The sealing contact surface of the inner sealing lip forms a sealing fit with the rotating member. The liquid-proximity end of the inner sealing lip is close to the liquid side, and the gas-proximity end of the inner sealing lip is close to the gas side.

[0014] A sealing structure for an air cushion seal includes a fixed component and a rotating component, and also includes the aforementioned air cushion seal. The fixed contact surface of the fixed outer frame is connected to the fixed component, and the sealing contact surface of the sealing inner lip forms a sealing fit with the rotating component. The liquid-proximity end of the sealing inner lip is close to the liquid side, and the gas-proximity end of the sealing inner lip is close to the gas side.

[0015] The beneficial effects of this application are:

[0016] (1) Based on the pneumatic principle of the wedge-shaped pump groove, the gas generates a wedge effect at the pump groove when rotating at high speed, thereby forming an air cushion between the rotating component and the inner lip of the seal, reducing the frictional loss between the seal and the rotating component, and ensuring the long-term dynamic sealing effect of the seal under high-speed conditions.

[0017] (2) The elastic waist provides elastic force to the inner sealing lip. Even if the inner sealing lip is worn due to friction, the inner sealing lip can self-compensate under the action of elastic force, ensuring the sealing effect of the inner sealing lip on the rotating component.

[0018] (3) The pump pressure groove includes a main groove in the forward rotation direction and a secondary groove in the reverse rotation direction. Under most forward rotation conditions, the main groove continuously ensures the sealing of the component under high-speed rotation. Under a small number of reverse rotation conditions, the secondary groove can maintain the sealing of the component under reduced speed rotation for a period of time, thus meeting various sealing requirements.

[0019] The aforementioned main solution and its various further alternatives can be freely combined to form multiple solutions, all of which are solutions that can be adopted and are claimed in this application; furthermore, the (non-conflicting alternatives) can also be freely combined with each other and with other alternatives. Those skilled in the art, after understanding this solution, will realize from the prior art and common general knowledge that there are many combinations, all of which are technical solutions to be protected in this application, and will not be exhaustively listed here. Attached Figure Description

[0020] Figure 1 This is a structural schematic diagram of the sealing element in this application.

[0021] Figure 2 This is a schematic diagram of the sealing structure of this application.

[0022] In the diagram: 1-Fixed outer frame, 2-Elastic waist, 3-Sealing inner lip, 101-Axial section, 102-Radial section, 103-Support frame, 104-Fixed flange, 201-Near air bend, 202-Sloping waist section, 203-Near liquid bend, 302-Ventilation groove, 303-Main pump pressure groove, 304-Auxiliary pump pressure groove, 305-Weir area, 306-Dam area; 100-Fixed component, 200-Rotating component, 10-Liquid side, 20-Air side. Detailed Implementation

[0023] The present application will be further described below with reference to specific embodiments and accompanying drawings.

[0024] Example 1

[0025] refer to Figure 1 As shown, an air cushion seal includes a fixed outer frame 1, an elastic waist 2, and a sealing inner lip 3. The fixed outer frame 1 is connected to the outer end of the elastic waist 2, and the inner end of the elastic waist 2 is connected to the sealing inner lip 3.

[0026] The fixed outer frame 1 is used to connect and fix the seal to the fixed component. The elastic waist 2 is used for the transition between the outer frame and the inner lip and provides elastic force to the inner lip. The sealing inner lip 3 is used to cooperate with the rotating component to perform the specific sealing function.

[0027] The fixed outer frame 1 has an L-shaped cross-section structure. One section (radial section) of the L-shape of the fixed outer frame 1 is connected to the outer end of the elastic waist 2, and the other section (axial section) of the L-shape of the fixed outer frame 1 is used to achieve fixation on the fixed component.

[0028] The other section of the L-shape of the fixed outer frame 1 faces the same side (liquid side) as the elastic waist 2. The elastic waist 2 is arranged at an angle. This structure is relatively simple, ensuring that the fixed outer frame 1 achieves the fixing function, while ensuring that the elastic waist 2 achieves the elastic transition function, and that the outer frame and waist do not occupy too much axial and radial space, thus enabling the use of small spaces.

[0029] The elastic waist 2 provides elastic force to the sealing inner lip 3. Even if the sealing inner lip 3 is worn due to friction, it can self-compensate under the action of elastic force, ensuring the sealing effect of the sealing inner lip on the rotating component. The sealing inner lip 3 is arranged in the same direction (axially) as the other section of the L-shape of the fixed outer frame 1, and the sealing effect on the outer peripheral surface of the shaft is directly achieved by the sealing inner lip 3, reducing the overall space volume of the sealing component.

[0030] The fixed outer frame 1 includes an axial section 101, a radial section 102, a support frame 103, and a fixing flange 104. Except for the support frame 103, which is preferably made of metal, the rest are preferably made of rubber. The near-air end of the axial section 101 (near-air means close to the gas, the same below) is vertically and integrally connected to the outer end of the radial section 102, thereby forming an L-shaped cross-section structure. The inner end of the radial section 102 is integrally connected to the elastic waist 2.

[0031] An L-shaped support frame 103 is embedded in both the axial section 101 and the radial section 102 to provide structural support and stability to the outer frame. Preferably, the support frame 103 is exposed on the inner circumferential surface of the axial section 101 and the near-liquid surface of the radial section 102 (near-liquid means close to the liquid, the same below). The fixed contact surface of the axial section 101, i.e., the outer circumferential surface, is integrally provided with a fixing flange 104 to facilitate the fixing operation of the outer frame.

[0032] The elastic waist section 2 includes an integrally structured air-prone bend 201, a sloping waist section 202, and a liquid-prone bend 203, all preferably made of rubber. The outer end of the sloping waist section 202 is integrally connected to the radial section 102 of the fixed outer frame 1 via the air-prone bend 201, achieving a transition from the thicker radial section 102 to the thinner sloping waist section 202. The inner end of the sloping waist section 202 is integrally connected to the outer peripheral surface of the sealing inner lip 3 via the liquid-prone bend 203, achieving a bending transition from the sloping waist section 202 to the axial sealing inner lip 3.

[0033] The sealing inner lip 3 is made of rubber and includes an outer circumferential surface and an inner circumferential surface. The sealing contact surface of the sealing inner lip 3, i.e., the inner circumferential surface, is provided with a vent groove 302 and a pumping groove. The vent groove 302 extends to the near-air end of the sealing inner lip 3, allowing air from the air side to enter the vent groove 302. The sealing contact surface of the sealing inner lip 3 is provided with a pumping groove that communicates with the vent groove 302. The pumping groove is used to form an air cushion when the rotating component rotates.

[0034] The pump pressure grooves are arranged circumferentially and have a wedge-shaped structure. When rotating at high speed, the gas generates a wedge effect at the pump pressure grooves. That is, the gas enters the pump pressure grooves through the vent grooves 302, and the rotating component drives the gas to move. The gas flows into the wedge-shaped convergent gap of the pump pressure grooves and generates pressurized gas, thereby forming an air cushion between the rotating component and the inner sealing lip, reducing frictional loss between the seal and the rotating component.

[0035] Several vent grooves 302 are provided, arranged axially, and spaced apart circumferentially on the inner sealing lip 3. Each vent groove 302 is connected to several pump pressure grooves, achieving a uniform distribution of the pump pressure grooves on the sealing contact surface and ensuring balanced support of the sealing element for the rotating component. For example, the vent grooves 302 can be arranged in multiple rows, and the pump pressure grooves can be arranged in multiple layers.

[0036] Since the venting groove 302 does not extend to the liquid-prone end of the inner sealing lip 3, a weir area 305 is formed on the sealing contact surface of the inner sealing lip 3 at the liquid-prone end, blocking the gas entering the venting groove 302 and generating air pressure to form an air cushion effect. The area between two adjacent venting grooves and pump pressure grooves on the sealing contact surface of the inner sealing lip 3 is the dam area 306.

[0037] The pump pressure groove includes a main pump pressure groove 303 and an auxiliary pump pressure groove 304. The groove length (arc length) of the main pump pressure groove 303 is greater than the groove length (arc length) of the auxiliary pump pressure groove 304. The main pump pressure groove 303 is arranged in the forward rotation direction of the inner sealing lip 3 (i.e., the direction of forward rotation of the rotating component), and the auxiliary pump pressure groove 304 is arranged in the reverse rotation direction of the inner sealing lip 3 (i.e., the direction of reverse rotation of the rotating component).

[0038] The rotating components include forward high-speed rotation conditions with a maximum speed of 30,000 rpm and reverse deceleration conditions with a speed of less than 10,000 rpm (based on the reduction in forward speed). Under most forward rotation conditions, a wedge effect is generated in the main pump pressure groove 303 to continuously ensure the sealing of the components under high-speed rotation. Under a small number of reverse rotation conditions, a wedge effect is generated in the auxiliary pump pressure groove 304 to maintain the sealing of the components under deceleration rotation for a period of time.

[0039] The pump pressure grooves (main pump pressure groove 303 and auxiliary pump pressure groove 304) include a flat bottom edge, an inclined side edge, and an inclined top edge forming a wedge-shaped structure. The flat bottom edge is parallel to the circumferential direction of the sealing inner lip 3. An angle α is formed between the inclined side edge and the flat bottom edge, and an angle β is formed between the inclined top edge and the flat bottom edge. α is 10° to 15°, and β is 2° to 10°. The groove depth of the pump pressure grooves (main pump pressure groove 303 and auxiliary pump pressure groove 304) is h, and h is 0.01mm to 0.05mm. This can create a good aerodynamic effect and ensure the stability and reliability of the air cushion.

[0040] Example 2

[0041] refer to Figure 1 and Figure 2 As shown, a sealing structure for an air cushion seal includes a rotating member 200 and the air cushion seal of Embodiment 1. The sealing contact surface (inner circumferential surface) of the inner sealing lip 3 forms a sealing fit with the rotating member 200 (shaft). The liquid-proximity end of the inner sealing lip 3 is close to the liquid side 10, and the gas-proximity end of the inner sealing lip 3 is close to the gas side 20.

[0042] Under sealing conditions, air from the gas side enters the pump pressure groove through the vent groove. Due to the wedge effect of the fluid, pressurized gas is formed, creating a certain air cushion between the rotating component (shaft) and the inner sealing lip, thereby reducing the friction between the inner sealing lip and the rotating component (shaft). Simultaneously, the pump pressure groove can pump the sealed liquid (lubricating oil) back to the liquid side. Because the main pump pressure groove has a greater pumping capacity than the auxiliary pump pressure groove, long-term dynamic sealing can be achieved at speeds up to 30,000 rpm. When the rotating component (shaft) rotates in the opposite direction, the fluid film thickness is smaller due to the lower speed. The pumping effect of the auxiliary pump pressure groove can maintain liquid (lubricating oil) leak-free operation for a period of time at speeds up to 10,000 rpm.

[0043] Example 3

[0044] refer to Figure 1 and Figure 2 As shown, a sealing structure for an air cushion seal includes a fixed member 100 and a rotating member 200, and also includes the air cushion seal of Embodiment 1. The fixed contact surface (outer peripheral surface) of the fixed outer frame 1 is fixedly connected to the fixed member 100, and the sealing contact surface (inner peripheral surface) of the sealing inner lip 3 forms a sealing fit with the rotating member 200. The liquid-proximity end of the sealing inner lip 3 is close to the liquid side 10, and the gas-proximity end of the sealing inner lip 3 is close to the gas side 20.

[0045] The workflow of this embodiment is the same as that of embodiment 2. At the same time, the fixed outer frame 1 supports the elastic waist 2, and the elastic waist 2 exerts an elastic force on the sealing inner lip 3. Under the action of the elastic force, the sealing inner lip can perform self-compensation.

[0046] The foregoing basic examples and their further alternative examples can be freely combined to form multiple embodiments, all of which are embodiments that can be adopted and claimed in this application. In the scheme of this application, each alternative example can be arbitrarily combined with any other basic example and alternative example.

[0047] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. An air cushion seal, comprising a sealing inner lip (3), characterized in that: The sealing contact surface of the inner sealing lip (3) is provided with a venting groove (302), which extends to the near-air end of the inner sealing lip (3). The sealing contact surface of the inner sealing lip (3) is provided with a pump pressure groove that communicates with the venting groove (302). The pump pressure groove is arranged circumferentially and has a wedge-shaped structure.

2. The air cushion seal according to claim 1, characterized in that: It also includes a fixed outer frame (1) and an elastic waist (2), the fixed outer frame (1) is connected to the outer end of the elastic waist (2), and the inner end of the elastic waist (2) is connected to the sealing inner lip (3).

3. The air cushion seal according to claim 2, characterized in that: The fixed outer frame (1) has an L-shaped cross-section structure. One end of the L-shaped fixed outer frame (1) is connected to the elastic waist (2), and the other end of the L-shaped fixed outer frame (1) and the elastic waist (2) face the same side. The elastic waist (2) is arranged at an angle, and the sealing inner lip (3) is arranged in the same direction as the other end of the L-shaped fixed outer frame (1).

4. The air cushion seal according to claim 2 or 3, characterized in that: The fixed outer frame (1) includes an axial section (101) and a radial section (102). The near end of the axial section (101) is connected to the outer end of the radial section (102), and the inner end of the radial section (102) is connected to the elastic waist (2). An L-shaped support frame (103) is embedded in both the axial section (101) and the radial section (102). The fixed contact surface of the axial section (101) is provided with a fixed flange (104).

5. The air cushion seal according to claim 2 or 3, characterized in that: The elastic waist (2) includes an inclined waist section (202), the outer end of which is connected to the fixed outer frame (1) via a near air angle head (201), and the inner end of which is connected to the sealing inner lip (3) via a near liquid bend head (203).

6. The air cushion seal according to claim 1, 2 or 3, characterized in that: The ventilation groove (302) is provided in several ways. The ventilation groove (302) is arranged at intervals along the circumferential direction on the sealing inner lip (3). Each ventilation groove (302) is connected to several pump pressure grooves.

7. The air cushion seal according to claim 1, 2 or 3, characterized in that: The pump pressure groove includes a main pump pressure groove (303) and a secondary pump pressure groove (304). The groove length of the main pump pressure groove (303) is greater than the groove length of the secondary pump pressure groove (304). The main pump pressure groove (303) is arranged in the forward rotation direction of the sealing inner lip (3), and the secondary pump pressure groove (304) is arranged in the reverse rotation direction of the sealing inner lip (3).

8. The air cushion seal according to claim 1, 2 or 3, characterized in that: The pump pressure groove includes a flat bottom edge, a sloping side edge, and a sloping top edge forming a wedge-shaped structure. The flat bottom edge is parallel to the circumferential direction of the inner sealing lip (3). An angle α is formed between the sloping side edge and the flat bottom edge, and an angle β is formed between the sloping top edge and the flat bottom edge. α is 10° to 15°, and β is 2° to 10°. The groove depth of the pump pressure groove is h, and h is 0.01 mm to 0.05 mm.

9. A sealing structure for an air cushion seal, comprising a rotating member (200), characterized in that: It also includes the air cushion seal according to any one of claims 1 to 8, wherein the sealing contact surface of the sealing inner lip (3) forms a sealing fit with the rotating member (200), the liquid end of the sealing inner lip (3) is close to the liquid side (10), and the air end of the sealing inner lip (3) is close to the air side (20).

10. A sealing structure for an air cushion seal, comprising a fixed member (100) and a rotating member (200), characterized in that: It also includes the air cushion seal as described in any one of claims 2 to 8, wherein the fixed contact surface of the fixed outer frame (1) is connected to the fixed member (100), the sealing contact surface of the sealing inner lip (3) forms a sealing fit with the rotating member (200), the liquid-side end of the sealing inner lip (3) is close to the liquid side (10), and the gas-side end of the sealing inner lip (3) is close to the gas side (20).

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