Pressure relief type oil seal conducting strip

Abstract

The utility model relates to the field of rotating motors, in particular to a pressure relief type oil seal conducting strip which comprises an annular sealing lip, the sealing lip is bent towards the outside of a motor, the thickness of the sealing lip is gradually reduced in the direction of an inner hole, the inner diameter of the inner hole of the sealing lip is smaller than the outer diameter of a rotating shaft, the sealing lip abuts against the rotating shaft of the motor, and the sealing lip is made of elastic materials. The sealing lip is attached to the rotating shaft of the motor to isolate the inside and outside of the motor, and when the internal pressure of the motor is too large, the sealing lip can release the internal pressure of the motor and isolate grease or impurities outside the motor from entering the motor at the same time.

Description

Technical Field

[0001] The present application relates to the field of rotating electrical machines, and in particular to a pressure relief oil seal conductive sheet. Background Art

[0002] In recent years, the development of electric motors, core components of the drive and power generation units of new energy vehicles, has accelerated rapidly. On the one hand, to achieve widespread adoption of the high-voltage 800V platform, silicon carbide-based inverters are being widely used in new energy passenger and commercial vehicles. High voltage and high switching frequency can exacerbate shaft current corrosion. On the other hand, fierce market competition has further increased the reliability and high power density requirements for motors, electronic controls, and other products.

[0003] Most motors are only equipped with oil seals to ensure the sealing performance of the motor, and the oil seals are installed at the output end of the motor. Some motors with higher currents are additionally equipped with conductive rings to reduce shaft current corrosion. The conductive rings need to be reserved for installation during the design, usually on the non-output side. Conventional assembly solutions can meet the motor sealing requirements and anti-electrical corrosion requirements, but there is a certain margin requirement for the axial installation space at both ends of the motor. If the motor is to achieve a higher power density, the motor volume needs to be further optimized. However, when the motor punching platform is confirmed, its radial dimension optimization space is very limited. Therefore, it is necessary to optimize the motor axial dimension as much as possible to reduce the motor volume to achieve lightweight design requirements.

[0004] As the output power demand of the motor increases, the temperature inside the motor rises rapidly during the operation of the motor, causing the pressure inside the motor to also increase. If the pressure cannot be relieved in time, it will affect the sealing performance of the oil seal and the conductive efficiency of the conductive ring. Summary of the Invention

[0005] The technical problem to be solved by this application is to provide a pressure-relief oil seal conductive sheet, which is provided with a sealing lip that fits with the rotating shaft of the motor to isolate the inside and outside of the motor. When the internal pressure of the motor is too high, the sealing lip is further bent under pressure to release the internal pressure of the motor while isolating the external grease or impurities of the motor from entering the motor.

[0006] The present application adopts the following technical solution: a pressure relief oil seal conductive sheet, fixed on the motor, including an annular sealing lip, the sealing lip is bent toward the outside of the motor, the thickness of the sealing lip gradually decreases toward the inner hole, the inner diameter of the inner hole of the sealing lip is smaller than the outer diameter of the rotating shaft, the sealing lip abuts against the rotating shaft of the motor, and the sealing lip is made of elastic material.

[0007] Furthermore, the contact surface of the sealing lip abuts against the axial surface of the rotating shaft in a surface contact manner.

[0008] Further preferably, the contact width between the contact surface of the sealing lip and the axial surface of the rotating shaft is at least 2 mm.

[0009] Furthermore, it also includes a shell, the sealing lip is fixedly connected to the shell, and a gap is formed between the sealing lip and the shell after the sealing lip is bent.

[0010] Further preferably, the shell is a metal shell.

[0011] Preferably, the pressure relief oil seal conductive sheet is divided into a sealing area and a conductive area, the sealing area faces the outside of the motor, the sealing area and the conductive area are connected as a whole by the shell, the sealing area is fixedly connected to the sealing lip, and the conductive area is provided with several conductive fiber bundles in contact with the rotating shaft.

[0012] Further preferably, the conductive fiber bundles are distributed in an equidistant ring shape around the rotating shaft.

[0013] Further preferably, a weight-reducing groove is also provided on the shell.

[0014] Preferably, the pressure relief oil seal conductive sheet is connected to the motor by means of a transition fit or an interference fit.

[0015] Further preferably, the width of the fitting surface of the transition fit and the interference fit is greater than 0.5 times the width of the conductive sheet of the pressure relief oil seal.

[0016] Compared with the prior art, the beneficial effects achieved by this application include:

[0017] The inner hole diameter of the sealing lip of the present application is smaller than the outer diameter of the motor rotating shaft. The motor rotating shaft and the sealing lip have an interference fit. The sealing lip is further bent by the compression of the rotating shaft, thereby isolating the inside and outside of the motor and improving the sealing performance; when the internal pressure of the motor is too high, the pressure causes the sealing lip to bend further toward the outside of the motor, thereby reducing the internal pressure of the motor like a one-way valve, and at the same time isolating grease or impurities outside the motor from entering the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic cross-sectional view of the structure of the embodiment of the present application installed on the motor;

[0019] Figure 2 A schematic diagram of the internal structure of an embodiment of the present application;

[0020] Figure 3 This is a front view of an embodiment of the present application;

[0021] Figure 4 This is a schematic diagram of the sealing lip in a free state according to an embodiment of the present application;

[0022] Figure 5 This is a schematic diagram of the sealing lip in the installed state according to the embodiment of the present application;

[0023] In the figure: 1. Motor; 2. Pressure relief oil seal conductive sheet; 21. Housing; 22. Sealing lip; 23. Conductive fiber bundle; 24. Weight reduction groove; 3. Rotating shaft; A. Sealing area; B. Conductive area. DETAILED DESCRIPTION

[0024] To make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments.

[0025] Therefore, the following detailed description of the embodiments of the present application is not intended to limit the scope of the present application for protection, but merely represents some embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making any creative work are within the scope of protection of this application.

[0026] Example

[0027] See also Figures 1 to 5 This embodiment provides a pressure relief oil seal conductive sheet fixed on the motor 1, including an annular sealing lip 22, the sealing lip 22 is bent toward the outside of the motor 1, as shown in FIG. Figure 4 As shown, the thickness of the sealing lip 22 gradually decreases toward the inner hole. The inner diameter of the inner hole of the sealing lip 22 is smaller than the outer diameter of the rotating shaft 3. The sealing lip 22 abuts the rotating shaft 3 of the motor 1 and is made of an elastic material such as polytetrafluoroethylene. The sealing lip 22 bends toward the outside of the motor 1 to facilitate the escape of internal pressure from the motor 1. The inner hole diameter of the sealing lip 22 is smaller than the outer diameter of the rotating shaft 3 of the motor 1. The rotating shaft 3 of the motor 1 and the sealing lip 22 have an interference fit. The sealing lip 22 is squeezed by the rotating shaft 3 to further bend, thereby isolating the inside and outside of the motor 1 and improving the sealing performance. When the internal pressure of the motor 1 is too high, the pressure causes the sealing lip 22 to bend further toward the outside of the motor 1, thereby reducing the internal pressure of the motor 1 like a one-way valve and preventing grease or impurities from entering the motor 1.

[0028] like Figure 1 As shown, further, the fitting surface of the sealing lip 22 abuts against the axial surface of the rotating shaft 3 in a surface contact manner, thereby increasing the contact area between the sealing lip 22 and the rotating shaft 3, ensuring the reliability of the seal, and when the surface of the rotating shaft 3 is uneven due to long-term wear, the problem of sealing failure is not likely to occur.

[0029] Further preferably, in this embodiment, the contact width between the fitting surface of the sealing lip 22 and the axial surface of the rotating shaft 3 is at least 2 mm. The larger contact area further ensures that the motor 1 can be depressurized while preventing external impurities and grease from entering the motor 1.

[0030] like Figure 5 As shown, in this embodiment, the pressure relief oil seal conductive sheet 2 utilizes a rust-proofed metal housing, such as an aluminum alloy. The sealing lip 22 is fixedly connected to the housing 21, and a gap is formed between the sealing lip 22 and the housing 21 after bending. The metal housing 21 improves the conductivity of the pressure relief oil seal conductive sheet. The gap between the sealing lip 22 and the housing 21 allows space for the sealing lip 22 to bend further when the motor 1 is depressurized. This gap also serves to divert external grease and impurities from flowing above the sealing lip 22, while internal grease or air from the motor 1 flows out below the sealing lip 22, further preventing external impurities and grease from entering the motor 1.

[0031] In addition, the pressure relief oil seal conductive sheet 2 in this embodiment is further provided with a weight reduction groove 24 on the housing 21 , which is beneficial to the lightweight design of the motor 1 .

[0032] In this embodiment, Figure 2 As shown, the pressure relief oil seal conductive sheet 2 is divided into a sealing area and a conductive area. The sealing area faces the outside of the motor 1 and is connected to the conductive sheet by a housing 21. The sealing area is fixedly connected to the sealing lip 22. In this embodiment, 24 conductive fiber bundles 23 are fixed to the conductive sheet to contact the rotating shaft 3. The integration of the oil seal and conductive sheet improves the space utilization of the motor 1 design, reduces axial mounting locations, optimizes the axial dimensions of the motor 1, and simplifies the motor 1 structure. Furthermore, with the sealing area facing the outside of the motor 1 and the conductive area facing the inside, it effectively prevents corrosion of the sealing lip 22 caused by shaft current, thereby extending the service life of the pressure relief oil seal conductive sheet 2.

[0033] Further preferably, the conductive fiber bundle 23 is made of a mixture of carbon and metal, is connected to the conductive area through holes, and is distributed in an equidistant ring around the rotating shaft 3. The shaft current generated on the rotating shaft 3 is guided out of the motor 1 through the conductive fiber bundle 23, thereby avoiding electrical corrosion of the operating and sealing areas of the motor 1 by the shaft current, and can effectively solve the skin effect problem of high-frequency current.

[0034] As a preferred embodiment, the pressure relief oil seal conductive sheet 2 is connected to the motor 1 by means of a transition fit or an interference fit. The width of the fitting surface of the transition fit and the interference fit is greater than 0.5 times the width of the pressure relief oil seal conductive sheet 2, thereby increasing the fitting area between the pressure relief oil seal conductive sheet 2 and the motor 1 and making the connection between the two more secure. This prevents the pressure relief oil seal conductive sheet 2 from detaching from the motor 1 and causing the seal to fail due to the increase in internal pressure of the motor 1, thereby causing a malfunction.

[0035] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of protection of the present application is limited to these examples. In line with the present application, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of different aspects of one or more embodiments of the present application as described above, which are not provided in detail for the sake of simplicity.

[0036] The one or more embodiments of this application are intended to encompass all such substitutions, modifications, and variations that fall within the broad scope of this application. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of one or more embodiments of this application should be included in the scope of protection of this application.

Claims

1. A pressure relief oil seal conductive sheet fixed on a motor (1), characterized in that: The invention comprises an annular sealing lip (22), wherein the sealing lip (22) is bent toward the outside of the motor (1), the thickness of the sealing lip (22) gradually decreases toward the inner hole, the inner diameter of the inner hole of the sealing lip (22) is smaller than the outer diameter of the rotating shaft (3), the sealing lip (22) abuts against the rotating shaft (3) of the motor (1), and the sealing lip (22) is made of elastic material.

2. The pressure relief oil seal conductive sheet according to claim 1, characterized in that: The fitting surface of the sealing lip (22) abuts against the axial surface of the rotating shaft (3) in a surface contact manner.

3. The pressure relief oil seal conductive sheet according to claim 2, characterized in that: The contact width between the fitting surface of the sealing lip (22) and the axial surface of the rotating shaft (3) is at least 2 mm.

4. The pressure relief oil seal conductive sheet according to claim 1, characterized in that: It also includes a housing (21), a sealing lip (22) fixedly connected to the housing (21), and a gap between the sealing lip (22) and the housing (21) after being bent.

5. The pressure relief oil seal conductive sheet according to claim 4, characterized in that: The housing (21) is a metal housing.

6. The pressure relief oil seal conductive sheet according to claim 5, characterized in that: The pressure relief oil seal conductive sheet is divided into a sealing area and a conductive area. The sealing area faces the outside of the motor (1). The sealing area and the conductive area are connected as a whole by a housing (21). The sealing area is fixedly connected to the sealing lip (22). The conductive area is provided with a plurality of conductive fiber bundles (23) in contact with the rotating shaft (3).

7. The pressure relief oil seal conductive sheet according to claim 6, characterized in that: The conductive fiber bundles (23) are distributed in an equidistant annular pattern around the rotating shaft (3).

8. The pressure relief oil seal conductive sheet according to claim 6, characterized in that: The housing (21) is also provided with a weight-reducing groove (24).

9. The pressure relief oil seal conductive sheet according to claim 1, characterized in that: The pressure relief oil seal conductive sheet is connected to the motor (1) by means of a transition fit or an interference fit.

10. The pressure relief oil seal conductive sheet according to claim 9, characterized in that: The width of the fitting surface of the transition fit and the interference fit is greater than 0.5 times the width of the conductive sheet of the pressure relief oil seal.

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