A high-speed bearing and motor for electric drive assemblies

Abstract

This invention belongs to the field of bearing technology, specifically providing a high-speed bearing and motor for an electric drive assembly. The high-speed bearing for an electric drive assembly includes a bearing housing, rolling bearings, an oil-pushing assembly, and a sealing element. The rolling bearings are installed in the mounting cavity of the bearing housing, and an oil reservoir is provided at the bottom of the mounting cavity. The oil-pushing assembly is located in the oil reservoir. Before the motor cold starts, the oil level is raised by a piston, achieving complete immersion of all rolling elements. Subsequently, the piston descends, lowering the oil level. Before the motor stabilizes, the lubricating oil level in the oil reservoir has dropped below the center position of the lowest rolling element. This design ensures that an effective oil film is established between the rolling elements and the inner and outer rings of the bearing at the moment of motor startup, eliminating the risk of dry friction. It also avoids the high-speed rotation of the rolling elements causing violent agitation of the oil, which could lead to an increase in oil temperature.

Description

Technical Field

[0001] This application belongs to the field of bearing technology, specifically a high-speed bearing and motor for electric drive assemblies. Background Technology

[0002] High-speed bearings are common components in equipment such as automotive motors and machine tool spindle motors. During the high-speed operation of the bearing, the rotation of the rolling elements will cause wear and heat, requiring cooling and lubrication of the bearing interior to ensure long-term stable operation.

[0003] Existing lubrication methods for bearings are mainly divided into two categories: oil bath lubrication and oil spray lubrication. Traditional oil bath lubrication involves creating an oil reservoir at the bottom of the bearing housing, ensuring the oil level is at the center height of the lowest rolling element, allowing the rolling elements to contact the lubricating oil during bearing rotation. Oil spray lubrication uses an external oil pump to pressurize the lubricating oil, which is then sprayed directly onto the cage guide surface or rolling element surface through precision nozzles located near the bearing, achieving precise, point-to-point lubrication.

[0004] Both of the above lubrication methods have their own advantages and disadvantages. Oil injection lubrication relies heavily on the coordinated operation of complex components such as oil pumps, nozzles, pipelines, filters, and electronic control units. This makes system integration difficult, significantly increases manufacturing costs, and the presence of multiple external components introduces more potential failure points. The stringent requirements for oil cleanliness also increase the maintenance burden.

[0005] In applications such as modern high-speed motors, during cold starts, the areas of the bearing not in contact with lubricating oil are in a state of boundary lubrication or no lubrication. An effective oil film cannot form between the rolling elements and the raceway in time, easily leading to frictional heating and premature wear. Furthermore, the fixed oil level in oil bath lubrication causes excessive temperature rise in the rolling elements due to excessive stirring resistance during high-speed operation, failing to meet the operating requirements of high-speed bearings. Summary of the Invention

[0006] Based on the above-mentioned technical problems, this application provides a high-speed bearing and motor for electric drive assembly to solve the technical problems existing in the prior art, such as the bearing rolling elements being prone to dry friction during cold start of the motor and the bearing having a large churning force on the oil during high-speed operation, leading to aggravated temperature rise.

[0007] To achieve the above objectives, the technical solution adopted in this application is as follows: In a first aspect, this application provides a high-speed bearing for an electric drive assembly, comprising: The bearing housing has a mounting cavity for accommodating a rolling bearing, the central axis of the mounting cavity is arranged in a horizontal direction, the bottom wall of the mounting cavity has an oil storage cavity, and the opposite side walls of the mounting cavity have shaft holes for a rotating shaft to pass through. A rolling bearing, coaxially disposed within the mounting cavity, includes an outer ring, an inner ring, and a plurality of rolling elements disposed between the outer ring and the inner ring; An oil-pushing assembly includes a piston and a telescopic component. The piston is in sliding sealing engagement with the inner wall of the oil reservoir, and the telescopic component is used to drive the piston to move up and down. Two sealing elements are respectively disposed between the rotating shaft and the gap formed by the two shaft holes; Before the motor is cold-started, the telescopic component drives the piston to move upward, pushing the lubricating oil in the oil reservoir to at least submerge all the rolling elements; then the telescopic component drives the piston to move downward, and before the motor reaches the preset operating state, the lubricating oil level in the oil reservoir is lowered to below the center position of the lowest rolling element of the rolling bearing.

[0008] In one possible implementation, the oil storage chamber includes a first chamber and a second chamber spaced apart vertically, and a connecting hole connecting the first chamber and the second chamber; the first chamber is connected to the mounting cavity, the bottom of the first chamber is funnel-shaped, the inner diameter of the first chamber is smaller than that of the second chamber, and the inner diameter of the connecting hole is smaller than that of the first chamber; the piston is in sliding sealing engagement with the inner wall of the second chamber.

[0009] In one possible implementation, the sealing element includes: The mounting ring is annular and is disposed on the inner wall of the shaft hole; A sealing lip, which is annular in shape, is disposed on the inner wall of the mounting ring and adjacent to the mounting cavity, for forming a dynamic sealing contact with the rotating shaft; An airbag, in the shape of a ring, is axially spaced from the sealing lip and located on the side of the sealing lip opposite to the mounting cavity. The airbag has an inflatable internal cavity and an air passage for connecting to an external air source. Before the motor is cold-started, the airbag is inflated through the air passage until the airbag and the rotating shaft are sealed together; during the normal operation of the motor, the airbag is deflated and contracted to reduce or eliminate the contact pressure between the airbag and the rotating shaft.

[0010] In one possible implementation, the mounting ring has multiple air holes spaced apart along its circumference, the air holes are connected to the airbag to form the air passage, and the inner wall of the shaft hole has an annular groove, the groove being connected to the air holes.

[0011] In one possible implementation, the root of the sealing lip is connected to the mounting ring, and the free end of the sealing lip extends obliquely toward the mounting cavity to contact the rotating shaft.

[0012] In one possible implementation, the top surface of the piston is provided with a magnetic attraction element.

[0013] In one possible implementation, the top wall of the mounting cavity is provided with a vent, and a filter nozzle is installed in the vent.

[0014] In one possible implementation, the preset operating state includes the motor speed reaching a preset threshold or the operating time reaching a preset time.

[0015] In one possible implementation, the sidewall or bottom of the oil storage cavity is provided with a heat dissipation structure, which is a heat dissipation fin or a cooling channel opened within the wall thickness range of the bearing seat.

[0016] In one possible implementation, a liquid level sensor is also included, which is electrically connected to the controller and is used to monitor the lubricating oil level in real time. The controller is used to control the movement of the telescopic component.

[0017] Compared with the prior art, the advantages of the high-speed bearing for electric drive assemblies provided in this application are: This application provides a high-speed bearing for an electric drive assembly, comprising a bearing housing, a rolling bearing, an oil-pushing assembly, and a sealing element. The rolling bearing is installed in a mounting cavity of the bearing housing, and an oil reservoir is provided at the bottom of the mounting cavity. The oil-pushing assembly is located in the oil reservoir. Before the motor cold starts, the oil level is raised by a piston to completely submerge all rolling elements. Subsequently, the piston descends, causing the oil level to drop. Before the motor operates stably, the lubricating oil level in the oil reservoir has dropped below the center position of the lowest rolling element.

[0018] This configuration ensures that an effective oil film is established between the rolling elements and the inner and outer rings of the bearing at the moment of motor startup, completely eliminating dry friction and boundary lubrication, thus reducing the risk of starting wear. It also ensures that once the motor enters high-speed, stable operation, the oil level has dropped below the center height of the lowest rolling element, preventing violent churning of the oil due to high-speed rotation of the rolling elements. This minimizes churning losses and the resulting temperature rise, meeting the requirements of high-speed bearings for low power consumption and thermal stability.

[0019] Secondly, this application provides an electric motor, including a high-speed bearing for an electric drive assembly as described in any of the above implementations.

[0020] In one possible implementation, during motor operation, the position of the piston is dynamically adjusted based on real-time monitored bearing temperature or rotational speed to control the lubricating oil level to fluctuate within a preset range.

[0021] The motor provided in this application includes a high-speed bearing for an electric drive assembly as described in any of the above implementations, and has the same beneficial effects, which will not be repeated here. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 A perspective view of a high-speed bearing for an electric drive assembly provided in this application; Figure 2 An internal cross-sectional view of a high-speed bearing for an electric drive assembly provided in this application; Figure 3 for Figure 2 Enlarged view of part A in the middle; Figure 4 for Figure 2 Enlarged view of part B in the middle; Figure 5 This is a cross-sectional view of the sealing element in this application; Explanation of reference numerals in the attached figures: 10. Bearing housing; 11. Housing body; 111. Oil reservoir; 1111. First chamber; 1112. Second chamber; 1113. Connecting hole; 112. Vent; 113. Filter nozzle; 114. Groove; 12. Bearing end cap; 20. Rolling bearing; 21. Outer ring; 22. Inner ring; 23. Rolling element; 30. Oil pushing assembly; 31. Piston; 311. Magnetic suction element; 32. Telescopic element; 40. Sealing element; 41. Mounting ring; 411. Air hole; 42. Sealing lip; 43. Air bladder; 50. Rotating shaft. Detailed Implementation

[0024] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0025] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0026] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0027] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" or "several" means two or more, unless otherwise explicitly specified.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0029] Please refer to the following: Figures 1 to 5 The following describes a high-speed bearing and motor for an electric drive assembly provided in an embodiment of this application.

[0030] In a first aspect, embodiments of this application provide a high-speed bearing for an electric drive assembly, comprising a bearing housing 10, a rolling bearing 20, an oil-pushing assembly 30, and sealing elements 40. The bearing housing 10 has a mounting cavity for accommodating the rolling bearing 20, the central axis of which is horizontally oriented. An oil reservoir 111 is formed in the bottom wall of the mounting cavity. Shaft holes for a motor shaft 50 are respectively formed on two opposite side walls of the mounting cavity, and the two shaft holes are coaxially arranged with the mounting cavity. The rolling bearing 20 is coaxially disposed within the mounting cavity and includes an outer ring 21, an inner ring 22, and a plurality of rolling elements 23 disposed between the outer ring 21 and the inner ring 22. The oil-pushing assembly 30 includes a piston 31 and a telescopic member 32. The piston 31 is slidably sealed to the inner wall of the oil reservoir 111, and the telescopic member 32 is used to drive the piston 31 to move up and down. Two sealing elements 40 are respectively disposed between the shaft 50 and the gaps formed by the two shaft holes.

[0031] The telescopic component 32 is controlled by a controller. Before the motor cold starts, the telescopic component 32 drives the piston 31 to move upward, pushing the lubricating oil in the oil reservoir 111 to a height that at least submerges all the rolling elements 23. Subsequently, the telescopic component 32 drives the piston 31 to move downward, lowering the lubricating oil level in the oil reservoir 111 to below the center position of the lowest rolling element 23 of the rolling bearing 20 before the motor reaches the preset operating state. The preset operating state includes the motor speed reaching a preset threshold or the operating time reaching a preset time.

[0032] The bearing housing 10 includes a housing body 11 and a bearing end cover 12. The housing body 11 and the bearing end cover 12 are connected by bolts, and an annular sealing ring or sealing gasket is provided on the contact surface between the two to prevent leakage. The housing body 11 and the bearing end cover 12 can be made of high-strength alloy or cast iron materials, and their manufacturing processes can be precision casting, forging or machining.

[0033] The bearing housing 10 has an internal mounting cavity for accommodating the rolling bearing 20. The central axis of this mounting cavity is horizontally oriented to accommodate the layout of the shaft 50. The bottom of the mounting cavity is machined or pre-drilled during production to form a reservoir 111 for storing lubricating oil. The lubricating oil is a commercially available low-viscosity oil.

[0034] The rolling bearing 20 is coaxially assembled in the mounting cavity and can be a deep groove ball bearing, a tapered roller bearing, or an angular contact ball bearing. The rolling bearing 20 includes an outer ring 21 fixed to the inner wall of the mounting cavity, an inner ring 22 fixed to the rotating shaft 50, and a plurality of rolling elements 23 evenly spaced between the outer ring 21 and the inner ring 22 by a cage. Multiple rolling bearings 20 can be arranged side by side along the axial direction.

[0035] The oil-pushing assembly 30 is used to adjust the oil level of the lubricating oil. The oil-pushing assembly 30 includes a piston 31 and a telescopic member 32. The piston 31 is made of aluminum alloy or other materials, and its outer circumferential surface has grooves for installing sealing rings (such as O-rings), thereby forming a sliding and sealing fit with the inner wall of the oil reservoir 111, ensuring that the lubricating oil cannot leak from around the piston 31. The telescopic member 32 is used to drive the piston 31 to move up and down reciprocally within the oil reservoir 111.

[0036] The telescopic component 32 can be a small servo electric cylinder, a linear stepper motor, or a pneumatic cylinder, which controls the telescopic movement of the piston 31 through an electric, external hydraulic, or pneumatic system.

[0037] Two sealing elements 40 are respectively installed in the annular gap between the rotating shaft 50 and the two shaft holes to prevent lubricating oil in the mounting cavity from leaking outward along the rotating shaft 50 under dynamic or static conditions. Their material can be nitrile rubber, etc., and their structural type can be a rubber skeleton oil seal, a labyrinth seal, or a variable seal as described below.

[0038] The high-speed bearing provided in this application includes the following working stages during use: Cold start pre-lubrication stage: Before the motor cold start command is issued (such as before vehicle unlocking or equipment startup), the controller controls the telescopic component 32 to move, driving the piston 31 upward within the oil reservoir 111. The upward movement of the piston 31 compresses the lubricating oil in the oil reservoir 111, forcing the oil level to rise until all rolling elements 23 of the rolling bearing 20 are completely submerged. This ensures that at the moment the motor starts rotating, all surfaces of the rolling elements 23 and the raceways are covered with lubricating oil, establishing an effective lubrication film. Depending on the application, after the lubricating oil has submerged all rolling elements 23, the piston 31 can immediately return to its low position or remain at its high position for a period of time.

[0039] Initial start-up phase: During the initial start-up of the motor, the rotational speed of the motor shaft 50 and bearings is relatively low, and the requirements for heat and resistance are also low. At this time, the lubricating oil level can be relatively high. This allows time for the lubricating oil to drop to the required height and ensures sufficient lubrication.

[0040] Normal operation phase: After the motor successfully starts and reaches the preset operating state, for example, when the motor speed sensor detects that the speed has reached a preset threshold (e.g., 2000 rpm), or when the timer records that the running time has reached a preset time (e.g., 30 seconds), the piston 31 should ensure that it has descended to the set minimum point, and the lubricating oil level in the oil reservoir 111 has dropped to a low level, that is, below the center position of the lowest rolling element 23 of the rolling bearing 20, but above the lowest point of the rolling element 23. At this time, most of the rolling elements 23 are detached from the oil surface, significantly reducing the violent agitation of the lubricating oil by the rolling elements 23 during high-speed rotation. The bearing is lubricated by the lubricating oil carried by the pumping principle when the rolling elements 23 rotate at high speed. The large amount of lubricating oil in the oil reservoir 111 has good thermal conductivity and also serves as a bearing heat dissipation agent.

[0041] There is no specific limit to the lubricating oil level during normal operation; users can set it according to their actual needs. For example, if the center position height of the lowest rolling element 23 of the rolling bearing 20 is defined as 1 / 2h, then the lubricating oil level during normal operation can be between 1 / 4h and 1 / 2h.

[0042] Compared with the prior art, the advantages of the high-speed bearing for electric drive assemblies provided in this application are: This application provides a high-speed bearing for an electric drive assembly, comprising a bearing housing 10, a rolling bearing 20, an oil-pushing assembly 30, and a sealing element 40. The rolling bearing 20 is installed in the mounting cavity of the bearing housing 10, and an oil reservoir 111 is provided at the bottom of the mounting cavity. The oil-pushing assembly 30 is disposed in the oil reservoir 111. Before the motor is cold-started, the oil level is raised by the piston 31 to achieve complete immersion of all rolling elements 23. Subsequently, the piston 31 descends, causing the oil level to drop accordingly. Before the motor is running stably, the lubricating oil level in the oil reservoir 111 has dropped below the center position of the lowest rolling element 23.

[0043] This configuration ensures that an effective oil film is established between the rolling element 23 and the inner and outer rings 22 and 21 of the bearing at the moment of motor startup, completely eliminating dry friction and boundary lubrication, and reducing the risk of startup wear. It also ensures that once the motor enters high-speed stable operation, the oil level has dropped below the center height of the lowest rolling element 23, thus preventing violent churning of the oil by the high-speed rotation of the rolling element 23, minimizing churning losses and resulting temperature rise, and meeting the requirements of high-speed bearings for low power consumption and thermal stability.

[0044] Please see Figure 4 The oil storage chamber 111 includes a first chamber 1111 and a second chamber 1112 arranged at an upper and lower interval, and a connecting hole 1113 connecting the first chamber 1111 and the second chamber 1112; the first chamber 1111 is connected to the mounting cavity, the bottom of the first chamber 1111 is funnel-shaped, the inner diameter of the first chamber 1111 is smaller than that of the second chamber 1112, and the inner diameter of the connecting hole 1113 is smaller than that of the first chamber 1111; the piston 31 is in sliding sealing cooperation with the inner wall of the second chamber 1112.

[0045] Because the cross-sectional area of ​​the second chamber 1112 is larger than that of the first chamber 1111, the piston 31 only needs a shorter stroke to push a large amount of lubricating oil through the connecting hole 1113 into the first chamber 1111, thereby quickly raising the liquid level in the mounting cavity and resulting in a faster response. The funnel-shaped bottom ensures that metal shavings generated by normal bearing wear can enter the second chamber 1112 under the action of gravity.

[0046] Please see Figure 3 and Figure 5 The sealing element 40 includes a mounting ring 41, a sealing lip 42, and an air bladder 43. The mounting ring 41 is annular and located on the inner wall of the shaft hole. The sealing lip 42 is annular, with its root fixed by vulcanization or mechanically pressed onto the inner wall of the mounting ring 41 and positioned adjacent to the mounting cavity to form a dynamic sealing contact with the rotating shaft 50. The sealing lip 42 is mainly responsible for preventing slight oil leakage during normal motor operation. The air bladder 43 is annular, axially spaced from the sealing lip 42, and located on the side of the sealing lip 42 away from the mounting cavity. The air bladder 43 has an inflatable internal cavity and an air passage for connecting to an external air source.

[0047] Before the motor cold starts, the airbag 43 inflates through the air passage until it seals against the shaft 50, forming a strong compression seal. This effectively seals the mounting cavity even when it is filled with lubricating oil, preventing slow leakage when the motor is stationary. During normal motor operation, the lubricating oil level drops to a preset height. At this point, the airbag 43 deflates and contracts, reducing or eliminating the contact pressure between the airbag 43 and the shaft 50, resulting in slight contact or a clearance fit. In this case, the sealing lip 42 is primarily responsible for dynamic sealing.

[0048] Please see Figure 5 The mounting ring 41 has multiple air holes 411 spaced apart along its circumference. The air holes 411 are connected to the airbag 43 to form an air passage. The inner wall of the shaft hole has an annular groove 114. The groove 114 is connected to the air holes 411 and the air outlet pipe of the air pump. The airbag 43 is inflated and deflated by the air pump and the groove 114, so that the airbag 43 can expand and contract evenly.

[0049] Please see Figure 3 and Figure 5 The root of the sealing lip 42 is fixedly connected to the mounting ring 41, and the free end of the sealing lip 42 extends obliquely toward the mounting cavity to contact the rotating shaft 50. When the pressure inside the mounting cavity is slightly high, the pressure will act on the back of the lip, making it fit more tightly with the rotating shaft 50, thereby achieving pressure-assisted self-tightening and improving the reliability of the dynamic seal.

[0050] One or more sealing lips 42 and airbags 43 can be provided as needed. When multiple sealing lips 42 and airbags 43 are provided, they can be provided alternately.

[0051] Please see Figure 2 and Figure 4 The piston 31 has a magnetic attractor 311 on its top surface. The magnetic attractor 311 is a permanent magnet used to attract metal shavings generated during the normal operation of the bearing.

[0052] Please see Figure 1 and Figure 2 The top wall of the mounting cavity is provided with a vent 112, and a filter nozzle 113 is installed in the vent 112. The vent 112 and the filter nozzle 113 are designed to prevent high-pressure air resistance caused by the compression of air inside the mounting cavity from hindering the rise of oil, thus ensuring the reliability and speed of the oil level lifting action. At the same time, when the piston 31 moves downward, the filter nozzle 113 allows external air to enter, balancing the pressure inside and outside the cavity.

[0053] The filter nozzle 113 has air intake and exhaust functions. It can be an air nozzle connected to the external atmosphere or a waterproof vent valve, capable of autonomously venting when the gas pressure inside the installation cavity changes. Alternatively, a solenoid valve or other air path control valve can be installed on the filter nozzle 113. The controller controls the opening of the solenoid valve based on the movement of the piston 31. When the solenoid valve is closed, the air intake and exhaust paths are cut off; when the solenoid valve is open, air can be introduced or exhausted to ensure pressure balance inside the installation cavity. Both the vent valve and the solenoid valve can be readily selected from existing commercially available products; there are no restrictions on their specific specifications or models, and users can choose according to their needs.

[0054] Considering that a large amount of heat may be generated when the high-speed bearing is running, a heat dissipation structure is provided on the outer wall or bottom of the oil storage cavity 111. The heat dissipation structure is a heat dissipation fin or a cooling channel opened within the wall thickness range of the bearing seat 10. The cooling channel is connected to an external liquid circulation pipeline, and a circulating cooling medium (such as water) is used to continuously cool and reduce the temperature of the lubricating oil in the oil storage cavity 111.

[0055] To monitor the oil level in the oil reservoir 111 in real time, a liquid level sensor is installed inside the reservoir 111. The liquid level sensor is electrically connected to the controller and is used to monitor the lubricating oil level in real time. The controller is used to control the movement of the telescopic component 32. The structure, working principle, and installation method of the liquid level sensor are all existing technologies and will not be described in detail here.

[0056] Secondly, embodiments of this application provide a motor, including a high-speed bearing for an electric drive assembly as described in any of the above embodiments, with the motor shaft, i.e., the rotating shaft 50, as the motor shaft. During motor operation, the position of the piston 31 is dynamically adjusted based on real-time monitoring of the bearing temperature or rotational speed to control the fluctuation of the lubricating oil level within a preset range. When the bearing operates at low speed (e.g., less than 1000 rpm), the oil level can be kept at a higher position (e.g., 2 / 3h), improving the lubrication effect.

[0057] It is understood that the parts in the above embodiments can be freely combined or deleted to form different combined embodiments. The specific contents of each combined embodiment will not be repeated here. After this description, it can be considered that the present invention specification has recorded each combined embodiment and can support different combined embodiments.

[0058] 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, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A high-speed bearing for an electric drive assembly, characterized in that, include: The bearing housing (10) has a mounting cavity for accommodating a rolling bearing (20), the central axis of the mounting cavity is arranged in the horizontal direction, the bottom wall of the mounting cavity is provided with an oil storage cavity (111), and the opposite side walls of the mounting cavity are respectively provided with shaft holes for the rotating shaft (50) to pass through. A rolling bearing (20) is coaxially disposed in the mounting cavity and includes an outer ring (21), an inner ring (22), and a plurality of rolling elements (23) disposed between the outer ring (21) and the inner ring (22). The oil-pushing assembly (30) includes a piston (31) and a telescopic member (32). The piston (31) is in sliding sealing cooperation with the inner wall of the oil reservoir (111), and the telescopic member (32) is used to drive the piston (31) to move up and down. Two sealing elements (40) are respectively disposed between the rotating shaft (50) and the gap formed by the two shaft holes; Before the motor is cold-started, the telescopic member (32) drives the piston (31) to move upward, pushing the lubricating oil in the oil reservoir (111) up to at least submerge all the rolling elements (23); then the telescopic member (32) drives the piston (31) to move downward, and before the motor reaches the preset operating state, the lubricating oil level in the oil reservoir (111) drops to below the center position of the lowest rolling element (23) of the rolling bearing (20).

2. The high-speed bearing for an electric drive assembly according to claim 1, characterized in that, The oil storage chamber (111) includes a first chamber (1111) and a second chamber (1112) arranged at an upper and lower interval, and a connecting hole (1113) connecting the first chamber (1111) and the second chamber (1112). The first chamber (1111) is connected to the mounting cavity. The bottom of the first chamber (1111) is funnel-shaped. The inner diameter of the first chamber (1111) is smaller than that of the second chamber (1112). The inner diameter of the connecting hole (1113) is smaller than that of the first chamber (1111). The piston (31) is in sliding sealing cooperation with the inner wall of the second chamber (1112).

3. The high-speed bearing for an electric drive assembly according to claim 1, characterized in that, The sealing element (40) includes: The mounting ring (41) is annular and is disposed on the inner wall of the shaft hole; A sealing lip (42), annular in shape, is disposed on the inner wall of the mounting ring (41) and adjacent to the mounting cavity, for forming a dynamic sealing contact with the rotating shaft (50); and An airbag (43) is annular and is axially spaced from the sealing lip (42) and located on the side of the sealing lip (42) away from the mounting cavity. The airbag (43) has an inflatable internal cavity. The airbag (43) has an air passage for connecting to an external air source. Before the motor is cold-started, the airbag (43) is inflated through the air passage until the airbag (43) and the rotating shaft (50) are sealed together; during the normal operation of the motor, the airbag (43) is deflated and contracted to reduce or eliminate the contact pressure between the airbag (43) and the rotating shaft (50).

4. The high-speed bearing for an electric drive assembly according to claim 3, characterized in that, The mounting ring (41) has a plurality of air holes (411) spaced apart along its circumference. The air holes (411) are connected to the airbag (43) to form the air passage. The inner wall of the shaft hole has an annular groove (114) connected to the air holes (411).

5. The high-speed bearing for an electric drive assembly according to claim 3, characterized in that, The root of the sealing lip (42) is connected to the mounting ring (41), and the free end of the sealing lip (42) extends obliquely toward the mounting cavity to contact the rotating shaft (50).

6. The high-speed bearing for an electric drive assembly according to claim 1, characterized in that, The piston (31) is provided with a magnetic suction element (311) on its top surface.

7. The high-speed bearing for an electric drive assembly according to claim 1, characterized in that, The top wall of the mounting cavity is provided with a vent (112), and a filter nozzle (113) is installed in the vent (112).

8. The high-speed bearing for an electric drive assembly according to claim 1, characterized in that, The preset operating states include the motor speed reaching a preset threshold or the operating time reaching a preset time.

9. An electric motor, characterized in that, Includes a high-speed bearing for an electric drive assembly as described in any one of claims 1 to 8.

10. The motor according to claim 9, characterized in that, During motor operation, the position of the piston (31) is dynamically adjusted according to the real-time monitored bearing temperature or speed to control the fluctuation of the lubricating oil level within a preset range.

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