Motor bearing and motor

Abstract

The invention relates to a motor bearing and a motor, and the motor bearing comprises an inner ring body, a ball and an outer ring body, and further comprises a sealing cavity which is arranged between the inner ring body and the outer ring body and is isolated from the ball; the sealing cavity is filled with the liquid electric conductor, and the liquid electric conductor makes contact with the inner ring body and the outer ring body. The liquid electric conductor is connected with the inner ring body and the outer ring body of the bearing, the inner ring body and the outer ring body are two electrodes at the same time, when the sealing cavity is filled with the liquid electric conductor, the two electrodes are soaked in liquid and are in a short-circuit state, and when the voltage difference exists between the two electrodes of the inner ring and the outer ring, common-mode axis current passes through the liquid electric conductor and flows through the liquid electric conductor. The liquid electric conductor enables the two electrodes to be short-circuited, the voltage difference between the two electrodes approaches to zero, no current passes between the inner ring and the outer ring of the bearing and the balls, the condition that electric corrosion pits are formed through breakdown does not exist, and therefore the bearing is not corroded any more.

Description

Technical Field

[0001] The present disclosure relates to the technical field of motor bearings, and in particular, to a motor bearing and a motor. Background Art

[0002] PWM (pulse width modulation) inverters or power modules generate high di / dt (current rate of change). This, due to distributed capacitance, creates common-mode voltage on the motor shaft or static charge buildup, resulting in shaft voltage. Excessive voltage can break through the oil film, causing electrical discharge (EDM) and creating ripples on the inner and outer races of bearings, generating vibration and noise, and shortening bearing life. Summary of the Invention

[0003] The purpose of the present disclosure is to provide a motor bearing and a motor, which can solve the above technical problems.

[0004] In order to achieve the above-mentioned purpose, the present disclosure provides a motor bearing, including an inner ring body, balls and an outer ring body, and the motor bearing also includes: a sealed cavity, arranged between the inner ring body and the outer ring body and isolated from the balls; and a liquid conductor, filled in the sealed cavity and in contact with both the inner ring body and the outer ring body.

[0005] Optionally, the inner ring body is provided with a first extension portion along its axial direction, the outer ring body is provided with a second extension portion along its axial direction, and the sealing cavity is provided between the first extension portion and the second extension portion.

[0006] Optionally, the sealing cavity includes a first trough body, a second trough body and a sealing device, the first trough body is arranged on the first extension part, the second trough body is arranged on the second extension part, the first trough body and the second trough body are buckled together, and the sealing device is arranged on the outside of the joint between the first trough body and the second trough body.

[0007] Optionally, the sealing cavity is constructed as an annular cavity arranged concentrically with the inner ring body or the outer ring body.

[0008] Optionally, the sealing device is configured as a sealing ring, and the sealing ring is provided on opposite sides of a joint between the first trough body and the second trough body.

[0009] Optionally, the volume of the liquid conductor is at least greater than 1 / 2 of the volume of the sealed cavity.

[0010] Optionally, the liquid conductor includes but is not limited to liquid metal.

[0011] Optionally, the outer ring body or the inner ring body is provided with an injection hole and an exhaust hole connected to the sealing cavity.

[0012] Optionally, the cross-sections of the first trough body and the second trough body are both configured as arc-shaped troughs.

[0013] A second object of the present disclosure is to provide a motor, comprising: the above-mentioned motor bearing.

[0014] Through the above technical solution, a liquid conductor is placed in a sealed cavity between the inner ring and the outer ring. Due to the seamless immersion connection of the liquid and the low resistance of the liquid conductor, the liquid conductor connects the inner ring and the outer ring of the bearing shaft. The inner ring and the outer ring are also two electrodes. When the sealed cavity is filled with liquid conductor, the two electrodes are immersed in the liquid and are in a short-circuit state. When there is a voltage difference between the inner and outer ring electrodes, the common-mode shaft current will pass through the liquid conductor, and the liquid conductor will short-circuit the two electrodes. The voltage difference between the two approaches zero, and no current passes between the inner and outer rings of the bearing and the balls. The conditions for breakdown and formation of electro-corrosion pits no longer exist. Therefore, the bearing will no longer corrode.

[0015] Other features and advantages of the present disclosure will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following detailed description, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings: Figure 1 is a schematic diagram of the external structure of the motor bearing in the present disclosure; Figure 2 yes Figure 1 DD cross-section diagram; Figure 3 yes Figure 2 A partial enlarged view of point E in the middle; Figure 4 is an equivalent circuit diagram of the motor bearing in the present disclosure.

[0017] Description of Reference Numerals 1. Outer ring; 11. Second extension; 2. Inner ring; 21. First extension; 3. Ball; 4. Sealing cavity; 41. First slot; 42. Second slot; 43. Sealing device; 5. Liquid conductor. DETAILED DESCRIPTION

[0018] The following describes the specific embodiments of the present disclosure in detail with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present disclosure and are not intended to limit the present disclosure.

[0019] In this disclosure, unless otherwise indicated, directional terms such as "inside" and "outside" refer to the inside and outside relative to the outline of a component or structure. Furthermore, it should be noted that terms such as "first" and "second" are used to distinguish one element from another and do not imply order or importance. Furthermore, in the description with reference to the accompanying drawings, the same reference numerals in different drawings represent the same element.

[0020] like Figure 1-3 As shown, the present disclosure provides a motor bearing, including an inner ring body 2, balls 3 and an outer ring body 1. The motor bearing also includes: a sealing cavity 4, which is arranged between the inner ring body 2 and the outer ring body 1 and is isolated from the balls 3; and a liquid conductor 5, which is filled in the sealing cavity 4 and is in contact with both the inner ring body 2 and the outer ring body 1.

[0021] Through the above technical solution, the liquid conductor 5 is placed in the sealed cavity 4 between the inner ring body 2 and the outer ring body 1. Due to the seamless immersion connection of the liquid and the low resistance of the liquid conductor 5, the liquid conductor 5 connects the inner ring body 2 and the outer ring body 1 of the bearing shaft. The inner ring body 2 and the outer ring body 1 are also two electrodes. When the sealed cavity 4 is filled with the liquid conductor 5, the two electrodes are immersed in the liquid and are in a short-circuit state. When there is a voltage difference between the inner and outer ring electrodes, the common-mode shaft current will pass through the liquid conductor 5. The liquid conductor 5 short-circuits the two electrodes, and the voltage difference between the two approaches zero. No current passes between the inner and outer rings of the bearing and the ball 3, and the conditions for breakdown to form electro-corrosion pits no longer exist. Therefore, the bearing will no longer corrode. Specifically, if Figure 4 As shown, the power module or inverter generates a common-mode interference source, Vc. The frequency / time domain characteristics and amplitude of Vc are related to the PWM (pulse width modulation) wave characteristics of the power module or inverter. The shorter the rise time of the PWM wave, the higher the frequency of the power module, and the greater the power, the larger the amplitude of Vc. The bearing's outer ring 1, balls 3, and the oil film between them form a distributed capacitance, C1. The bearing's inner ring 2, balls 3, and the oil film between them form a distributed capacitance, C2. The capacitance between the inner ring 2 and outer ring 1 is equivalent to the series connection of C1 and C2. The values of C1 and C2 are related to the bearing speed, pressure, and lubricant. When Vc exceeds the sum of the breakdown voltages of C1 and C2, C1 and / or C2 break down, forming electrolytic pits. This causes rubbing corrosion on the bearing's inner and outer ring raceways and the surface of ball 3. When the liquid conductor 5 short-circuits the inner ring 2 and the outer ring 1, it is equivalent to the switch K being turned on, C1 and C2 are short-circuited at the same time, no current flows between the inner and outer rings of the bearing and the ball 3, and the conditions for breakdown and formation of electrical corrosion pits no longer exist. Therefore, the bearing will no longer corrode.

[0022] As an optional implementation, Figure 2As shown, the inner ring body 2 is provided with a first extension portion 21 along its axial direction, and the outer ring body 1 is provided with a second extension portion 11 along its axial direction. The sealing cavity 4 is arranged between the first extension portion 21 and the second extension portion 11, that is, the sealing cavity 4 is arranged on the extension portion, so that the sealing cavity 4 can have an installation position and be spaced apart from the ball 3 to avoid electrical connection caused by communication with the ball 3.

[0023] Alternatively, as Figure 2-3 As shown, the sealed cavity 4 includes a first trough body 41, a second trough body 42 and a sealing device 43. The first trough body 41 is arranged on the first extension part 21, and the second trough body 42 is arranged on the second extension part 11. The first trough body 41 and the second trough body 42 are buckled together. The sealing device 43 is arranged on the outside of the joint between the first trough body 41 and the second trough body 42. The first trough body 41, the second trough body 42 and the sealing device 43 together form a sealed cavity 4. The first trough body 41 is arranged on the first extension part 21, and the second trough body 42 is arranged on the second extension part 11, so that the liquid conductor 5 can contact both the inner ring body 2 and the outer ring body 1, so that the inner ring body 2 and the outer ring body 1 are conductively connected.

[0024] As an optional embodiment, the sealing cavity 4 is constructed as an annular cavity arranged concentrically with the inner ring body 2 or the outer ring body 1, so as to ensure that the liquid conductor 5 is in contact with the inner ring body 2 and the outer ring body 1 regardless of how the inner ring body 2 and the outer ring body 1 rotate relative to each other.

[0025] Alternatively, as Figure 3 As shown, the sealing device 43 can be any suitable sealing member, such as an oil sealing device. For example, in the present disclosure, the sealing device 43 is constructed as a sealing ring, which is arranged on opposite sides of the joint between the first tank body 41 and the second tank body 42, that is, two sealing rings are provided, and the two sealing rings seal the gaps on both sides of the first tank body 41 and the second tank body 42 to prevent leakage of the liquid conductor 5.

[0026] As an optional implementation, Figure 3 As shown, the volume of the liquid conductor 5 is at least 1 / 2 the volume of the sealed cavity 4, ensuring that the liquid conductor 5 can immerse both electrodes under all motor speed conditions. The liquid conductor 5 does not need to completely fill the sealed cavity 4. The remaining space and gas in the cavity can be used to buffer the volume change of the liquid conductor 5 during solidification or melting at extremely low temperatures, balancing the pressure difference caused by thermal expansion and contraction. At the same time, the connectivity of the liquid conductor 5 is not affected, saving costs and reducing weight.

[0027] As an optional embodiment, the liquid conductor 5 includes, but is not limited to, liquid metals such as mercury and gallium-based metals. It can also be a conductive melt or a paste-like conductive material with a slightly higher viscosity coefficient. However, it is necessary to ensure that when the liquid conductor 5 is energized, it does not undergo electrochemical reactions, such as gas generation due to electrolysis, anode sacrificial phenomena, cathode growth, or changes in the properties of the liquid conductor 5. Furthermore, the liquid conductor 5 does not corrode, dissolve, or embrittle contacting metals or sealing structures.

[0028] As an optional embodiment, the outer ring body 1 or the inner ring body 2 is provided with an injection hole and an exhaust hole that communicate with the sealed cavity 4. The injection hole is used to inject the liquid conductor 5 into the sealed cavity 4, and the exhaust hole is used to exhaust air. When the liquid conductor 5 is injected through the injection hole, the exhaust hole exhausts air. After injection, the two holes are sealed to prevent the liquid conductor 5 from seeping out and air from circulating.

[0029] As an optional implementation, Figure 3 As shown, the cross sections of the first groove body 41 and the second groove body 42 are both constructed as arc-shaped grooves, which reduce the flow resistance of the liquid conductor 5 in the sealed cavity 4 and make the flow smoother.

[0030] The second object of the present disclosure is to provide a motor, comprising: the above-mentioned motor bearing, a liquid conductor 5 connecting the inner ring body 2 and the outer ring body 1 of the bearing shaft, the inner ring body 2 and the outer ring body 1 are also two electrodes. When the sealed cavity 4 is filled with the liquid conductor 5, the two electrodes are immersed in the liquid and are in a short-circuit state. When there is a voltage difference between the inner and outer ring electrodes, the common-mode shaft current will pass through the liquid conductor 5, and the liquid conductor 5 will short-circuit the two electrodes. The voltage difference between the two approaches zero, and no current passes between the inner and outer rings of the bearing and the ball 3. The conditions for breakdown to form electro-corrosion pits no longer exist. Therefore, the bearing will no longer corrode.

[0031] The preferred embodiments of the present disclosure are described in detail above in conjunction with the accompanying drawings. However, the present disclosure is not limited to the specific details of the above embodiments. Within the technical concept of the present disclosure, various simple modifications can be made to the technical solutions of the present disclosure, and these simple modifications all fall within the scope of protection of the present disclosure.

[0032] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, the present disclosure will not further describe various possible combinations.

[0033] In addition, the various embodiments of the present disclosure may be arbitrarily combined, and as long as they do not violate the concept of the present disclosure, they should also be regarded as the contents disclosed by the present disclosure.

Claims

1. A motor bearing, comprising an inner ring, balls and an outer ring, characterized in that: The motor bearing further comprises: a sealed cavity, disposed between the inner ring body and the outer ring body and isolated from the balls; and The liquid conductor is filled in the sealed cavity and contacts both the inner ring body and the outer ring body.

2. The motor bearing according to claim 1, characterized in that: The inner ring body is provided with a first extension portion along its axial direction, the outer ring body is provided with a second extension portion along its axial direction, and the sealing cavity is arranged between the first extension portion and the second extension portion.

3. The motor bearing according to claim 2, characterized in that: The sealed cavity includes a first trough body, a second trough body and a sealing device. The first trough body is arranged on the first extension part, the second trough body is arranged on the second extension part, the first trough body and the second trough body are buckled together, and the sealing device is arranged on the outside of the joint between the first trough body and the second trough body.

4. The motor bearing according to claim 1, characterized in that: The sealing cavity is constructed as an annular cavity concentrically arranged with the inner ring body or the outer ring body.

5. The motor bearing according to claim 3, characterized in that: The sealing device is configured as a sealing ring, which is disposed on opposite sides of a joint between the first trough body and the second trough body.

6. The motor bearing according to claim 1, characterized in that: The volume of the liquid conductor is at least greater than 1 / 2 of the volume of the sealed cavity.

7. The motor bearing according to claim 1, characterized in that: The liquid conductor includes but is not limited to liquid metal.

8. The motor bearing according to claim 1, characterized in that: The outer ring body or the inner ring body is provided with an injection hole and an exhaust hole communicated with the sealing cavity.

9. The motor bearing according to claim 3, characterized in that: The cross sections of the first trough body and the second trough body are both configured as arc-shaped troughs.

10. A motor, characterized in that: include: The motor bearing according to any one of claims 1 to 9.

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