Oil return structure and equipment

Abstract

The oil return structure and equipment are used for oil return of a motor and / or a gearbox, the motor and the gearbox are each provided with a machine shell and a rotating shaft, an inner oil cavity is formed in each machine shell, each inner oil cavity is provided with a first oil liquid level face, and an oil seal body used for sealing an opening of each inner oil cavity is arranged on each rotating shaft. The oil return structure comprises a negative pressure section and an oil throwing section which are arranged on the rotating shaft, an oil throwing structure which is arranged on the machine shell and corresponds to the oil throwing section, and a negative pressure structure which is arranged on the machine shell and corresponds to the negative pressure section. The scheme can effectively solve the problems of insufficient cooling caused by oil seal abrasion and oil leakage of the oil-cooled motor and damage to an insulation system caused by oil entering the motor due to oil leakage when the motor is matched with a gearbox, and improves the service life and stability of the motor.

Description

Technical Field

[0001] This invention relates to the field of oil-cooled motor structure technology, and in particular to an oil return structure and device for oil cooling. Background Technology

[0002] The statements in this section are merely background information related to this application and do not necessarily constitute prior art.

[0003] In recent years, with increasing environmental awareness and policy support, oil-cooled motors have been widely used in the field of new energy vehicles. Oil-cooled motors ensure the reliability of the stator and rotor by adjusting the cooling method of the stator and rotor, and improve the output power and power density of the motor.

[0004] In the process of developing this application, the applicant discovered that existing oil-cooled motors still have some problems. First, traditional oil seal structures are prone to wear, leading to oil leakage, insufficient cooling, and prolonged exposure of the insulation system to high temperatures, thus affecting the motor's service life. Second, when the motor is used with a gearbox, since the motor insulation system typically does not use oil-resistant materials, the gearbox oil is sealed by oil seals. Wear of these seals can cause oil leakage, which can then enter the motor insulation system and damage it, severely impacting the motor's performance and service life.

[0005] To address the aforementioned problems with oil-cooled motors and their compatibility with gearboxes, some oil-cooling or oil-sealing structures incorporate labyrinth seal rings and external oil seal rings at the rotor shaft and bearing connections, creating a seal on both sides of the bearing. When a small amount of oil leaks to the outside of the bearing, it flows back into the housing through connecting oil holes. However, the sealing effect of this structure varies under different speeds and temperatures. During motor or gearbox operation, the internal temperature and pressure rise, accelerating oil leakage from the oil seal leak or labyrinth structure. Other oil-sealing devices incorporate oil-slinger rings and return sleeves. Leaked lubricating oil flows back into the gearbox cover through the return groove and return hole of the return sleeve. This method has poor leakage prevention capabilities, and during motor or gearbox operation, the increased internal temperature and pressure prevent complete oil return, allowing lubricating oil to continue seeping out, thus reducing equipment performance and lifespan.

[0006] In view of this, how to solve the problems of accelerated oil leakage during operation, inability to achieve oil return, and easy oil leakage due to wear of the oil seals in existing oil-cooled motors and gearboxes has become the research topic to be solved by this invention. Summary of the Invention

[0007] This invention provides an oil return structure and device, the purpose of which is to solve the problems of accelerated oil leakage during operation, inability to achieve oil return, and easy oil leakage due to wear of the oil seals in existing oil-cooled motors and gearboxes.

[0008] To achieve the above objectives, the first aspect of the present invention adopts the following technical solution: providing an oil return structure for oil return from the motor and gearbox in an electric motor-gearbox assembly. The motor and gearbox have a sealed cavity at their mating point. Both the motor and gearbox have a housing and a shaft. The housing has an inner oil cavity with a first oil level surface. The shaft is provided with an oil seal structure for sealing the opening of the inner oil cavity. The oil return structure includes: The negative pressure section and the oil slinger section are provided on the rotating shaft. The negative pressure section is located at the rear end of the oil seal structure inside the housing, and the oil slinger section is located at the front end of the oil seal structure.

[0009] An oil-slinging structure is provided on the housing and corresponding to the oil-slinging section. The oil-slinging structure includes an oil collecting chamber and a reverse oil-slinging ring. The oil collecting chamber is connected to the interior of the inner oil chamber through an oil return hole. The oil collecting chamber has a second oil level surface. The reverse oil-slinging ring is coaxially mounted on the rotating shaft. The oil-slinging part at the rear end of the reverse oil-slinging ring extends into the oil collecting chamber.

[0010] A negative pressure structure is provided on the casing and corresponding to the negative pressure section. The negative pressure structure includes a negative pressure double impeller and a one-way vent valve. The negative pressure double impeller is coaxially mounted on the negative pressure section and is located near the oil return hole. A negative pressure chamber is formed at the position of the negative pressure double impeller near the oil return hole. The one-way vent valve is located on the casing above the middle of the double impellers of the negative pressure double impeller. The oil return structure is configured such that it is located in a sealed cavity at the junction of the motor and the gearbox. In at least one fixed position of the motor and the gearbox, the oil return hole is located above the first oil level. When the motor and the gearbox are running, the shaft drives the reverse oil slinger ring and the negative pressure double impeller to rotate. The reverse oil slinger ring throws the oil leaking from the oil seal structure into the oil collection chamber at the rear end. The rotation of the negative pressure double impeller forms a negative pressure path towards the inner oil chamber in the negative pressure chamber and the oil return hole. After the second oil level is higher than the oil return hole, the oil in the oil collection chamber enters the inner oil chamber through the negative pressure path.

[0011] The second aspect of the present invention adopts a technical solution as follows: a device is proposed, the device including a motor and a gearbox assembly, the mating part of the motor and the gearbox having a sealed cavity, and the sealed cavity having an oil return structure as described in the first aspect of the present invention.

[0012] The design principle and technical concept of this invention are: This invention addresses several issues related to the oil seal structure of existing oil-cooled motors and the oil seals in gearboxes when the motor is paired with a gearbox. These include insufficient cooling due to wear and leakage of the oil seal in the oil-cooled motor, and easy wear and leakage of the gearbox oil seal during motor-gearbox pairing, which damages the motor's insulation system. Therefore, a solution is urgently needed to effectively address these problems, improving the motor's lifespan and reliability. Simultaneously, the practicality, maintainability, and cost of the solution must be considered to meet practical application requirements. Based on this, the oil return structure of this invention and the equipment employing this structure were designed.

[0013] To meet the aforementioned special circumstances and requirements, the main part of the oil return structure is designed to include an oil-throwing structure and a negative pressure structure. The cooperation of these two structures allows oil leaking from the oil seal structure to be effectively returned to the motor or gearbox, achieving oil recycling and improving the overall system efficiency. Specifically, a negative pressure section is located at the rear end of the oil seal structure inside the housing, and an oil-throwing section is located at the front end of the oil seal structure inside the housing. An oil-throwing structure is provided corresponding to each oil-throwing section, including an oil collecting chamber and a reverse oil-throwing ring. The oil collecting chamber is connected to the internal oil return structure through an oil return hole. Inside the cavity, a reverse oil slinger ring is coaxially mounted on a rotating shaft. The rotation of the shaft synchronously drives the reverse oil slinger ring to rotate and sling oil. A negative pressure structure is set up corresponding to the negative pressure section. The negative pressure structure includes a negative pressure double impeller and a one-way vent valve. The negative pressure double impeller is coaxially mounted on the negative pressure section and is set close to the oil return hole. A negative pressure cavity is formed at the position of the negative pressure double impeller close to the oil return hole. The one-way vent valve is connected to the negative pressure cavity. The rotation of the shaft synchronously drives the negative pressure double impeller to rotate. The negative pressure double impeller generates negative pressure in the negative pressure cavity near the oil return hole, thereby quickly and effectively returning the oil in the oil collection cavity to the motor or gearbox. Furthermore, considering the characteristic that oil leakage becomes more severe at higher speeds in oil-cooled motors and transmissions, the oil slinger structure is placed at the front end of the oil seal structure, and the negative pressure structure is placed at the rear end of the oil seal structure. Combined with a one-way vent valve, this achieves the following functions: First, the negative pressure generated at the rear end of the oil seal structure slows down oil leakage. Second, the higher the speed, the greater the negative pressure, accelerating the return of oil from the oil collection chamber. Third, before the oil in the oil collection chamber reaches the lower end of the return oil hole, the higher the impeller speed, the greater the negative pressure generated, thus accelerating the return of oil from the oil collection chamber to the outside. The system is open to air, and the airflow flows from the outside to the negative pressure zone and then to the one-way vent valve for discharge, forming an effective circulation. After the oil in the oil collection chamber reaches the lower end of the return oil hole, the higher the impeller speed, the greater the negative pressure generated. Oil returns from the lower part of the return oil hole, while the upper part remains open to the outside air. The airflow flows from the outside to the negative pressure zone and then to the one-way vent valve for discharge, forming an effective circulation. The one-way vent valve allows for precise control of the oil flow direction, ensuring a smooth return oil process and preventing backflow of oil, further improving the system's sealing performance and reliability.Furthermore, in the oil return structure of this invention, the rotation of both the reverse oil slinger ring and the negative pressure double impeller is driven by the rotating shaft. The negative pressure chamber can be formed inside the casing, and the oil collection chamber is also reasonably designed. The oil return structure is simple and reasonable in design, easy to manufacture and install, and compared with traditional sealing structures, it has better practicality and economy, while also having strong adaptability, maintaining a stable sealing effect under different speed and temperature conditions. When the motor and gearbox are running, the rotating shaft drives the reverse oil slinger ring and the negative pressure double impeller to rotate. The reverse oil slinger ring throws the oil leaking from the oil seal structure into the oil collection chamber at the rear end, and the negative pressure double impeller... The impeller rotation creates a negative pressure path towards the inner oil cavity in the negative pressure chamber and oil return hole. After the second oil level is higher than the oil return hole, the oil in the oil collection chamber enters the inner oil cavity through the negative pressure path. The rotation of the negative pressure double impeller generates negative pressure, and the rotation of the reverse oil throwing ring throws the oil leaking from the oil seal structure towards the rear oil collection chamber. The oil in the oil collection chamber enters the inner oil cavity through the negative pressure path. This reasonable and ingenious design of airflow + liquid flow effectively solves the oil leakage problem when oil-cooled motors and gearboxes are connected, significantly improves the service life and reliability of the motor, and has important practical value.

[0014] The relevant content of this invention is explained as follows: 1. In the description of this application, it should be understood that the terms "front", "rear", "inner", "outer", "axial", "radial", "circumferential", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and 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, and therefore should not be construed as a limitation of this application.

[0015] 2. In the description of this application, the terms "installation," "connection," "linking," "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly defined. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0016] 3. In the description of this application, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0017] 4. In the above technical solution of the present invention, the oil collecting cavity is fixedly disposed at the front end of the housing, and the oil collecting cavity has an opening for passing through the rotating shaft and the reverse oil slinger ring. The inner diameter of the opening is larger than the outer diameter of the reverse oil slinger ring. This design makes the structure arrangement of the oil slinger structure more reasonable, so that there is no interference when the reverse oil slinger ring rotates rapidly.

[0018] 5. In the above technical solution of the present invention, in at least one fixed position of the motor and the gearbox, the lower part of the opening is higher than the horizontal position of the oil return hole, and the bottom position inside the oil collecting chamber is lower than the horizontal position of the oil return hole. This design ensures that the second oil level in the oil collecting chamber is always lower than the lower part of the opening, thereby avoiding the possibility of oil seeping out from the opening in extreme cases and making the oil return process more reasonable.

[0019] 6. In the above technical solution of the present invention, the oil return hole is inclined, and one end of the oil return hole in the negative pressure chamber is lower than one end of the middle oil collection chamber. That is, along the radial direction of the rotating shaft, the rear end opening of the oil return hole is closer to the axis of the rotating shaft than the front end opening. When the front end opening of the oil return hole is set at a lower position of the second oil level, the height of the rear end opening is lower than the height of the front end opening, so that the oil can flow more smoothly into the inner oil chamber of the housing. Negative pressure is generated during the downward flow of the oil. When the rotating shaft stops rotating, the oil in the oil collection chamber can also be smoothly drawn into the inner oil chamber. This design also has another function, which is that when the new energy vehicle is on a single-sided inclined road section, the tilt of the motor will not cause the oil in the first oil level on the inner oil chamber of the housing to backflow out of the oil return hole, thereby ensuring that the new energy vehicle using this oil return structure has good stability and reliability on various road surfaces and under various conditions.

[0020] 7. In the above technical solution of the present invention, the inner wall of the oil collecting chamber is provided with an anti-corrosion coating to prevent corrosion by oil, improve the service life of the oil return structure, and reduce the maintenance cycle of the motor or gearbox.

[0021] 8. In the above technical solution of the present invention, the inner side of the oil-throwing part of the reverse oil-throwing ring is provided with a plurality of guide grooves for oil flow. The guide grooves are evenly distributed radially. This radially evenly distributed guide groove design is conducive to the rapid throwing out of the oil. Combined with the rapid rotation of the reverse oil-throwing ring following the rotating shaft, the oil can be thrown into the oil collection chamber in the first time, thereby accelerating the oil circulation.

[0022] 9. In the above technical solution of the present invention, the oil-throwing part of the reverse oil-throwing ring has a first curved segment and a second curved segment from front to back. The first curved segment is located on the front side of the oil collecting chamber, and the second curved segment is located on the inner side of the oil collecting chamber. The distance between a portion of the second curved segment and the central axis of the rotating shaft is less than the distance between the first curved segment and the central axis of the rotating shaft. With this design, the inner diameter of a portion of the first curved segment is larger than the inner diameter of the second curved segment. After the oil seeping out of the rotating shaft is blocked by the reverse oil-throwing ring, the oil is thrown from the front end towards the rear end. When flowing from the first curved segment to the second curved segment, the decrease in inner diameter and the change in centrifugal force allow the oil to be more effectively thrown towards the inner wall of the oil collecting chamber under the action of centrifugal force. Furthermore, this hyperbolic arrangement reduces the space occupied by the reverse oil-throwing ring, allowing for a more compact design. Simultaneously, this structure, combined with a radially distributed uniformly distributed guide groove design, can significantly improve the oil-throwing effect, enhance the local structural strength, and extend the service life of the reverse oil-throwing ring.

[0023] 10. In the above technical solution of the present invention, the negative pressure double impeller adopts a double-blade impeller structure. During the operation of the motor, both the forward and reverse rotation of the shaft will generate negative pressure at the oil return hole, thereby stably providing negative pressure and ensuring the orderly return of oil. The double-blade impeller structure, through its symmetrical blade geometry design and bidirectional adaptability of the flow channel, can effectively perform work on the fluid through the impeller during both forward and reverse rotation, maintaining a low-pressure state near the oil return hole of the negative pressure double impeller to form a continuous and effective negative pressure area. Since the double-blade impeller structure is an existing structural design, it will not be described in detail here.

[0024] 11. In the above technical solution of the present invention, the one-way vent valve is located on the housing above the negative pressure double impeller, and a negative pressure chamber is formed inside the housing. The one-way vent valve is located above the negative pressure chamber and can directly connect the excessive negative pressure generated in the negative pressure chamber to the external atmosphere. The one-way vent valve can only release air from the inside out and cannot release air from the outside in. It is used to form negative pressure in the oil return hole to control the flow direction of the oil. Furthermore, since the diameter of the mist or gaseous oil and gas particles is relatively large, they cannot be discharged through the one-way vent valve.

[0025] 12. In the above technical solution of the present invention, the oil seal structure of the inner oil cavity inside the oil-cooled motor or gearbox is sealed by an oil seal body or a labyrinth seal. Before the oil seal structure fails, there will be basically no oil leakage. After the oil seal structure fails, a small amount of oil will leak out from the gap of the oil seal structure. After the small amount of oil leaks out, it will flow along the rotating shaft to the reverse oil slinger ring, or be directly slinged into the oil collection cavity. Since a negative pressure is always formed in the negative pressure cavity, the small amount of oil in the oil collection cavity can be directly recovered into the machine housing through the oil return hole, and too much oil will accumulate in the oil collection cavity.

[0026] 13. In the above technical solution of the present invention, multiple oil return holes are provided on the front end cover of the housing, and unused oil return holes can be plugged with plugs. At the same time, the cross-section of the oil return holes is designed to be larger than the area of ​​the gap generated after the oil seal structure is worn, so as to increase the negative pressure and enable rapid oil return.

[0027] Due to the application of the above-mentioned solution, the present invention has the following advantages and effects compared with the prior art: 1. The above-mentioned solution of the present invention addresses some problems existing in the oil seal structure of oil-cooled motors and the oil seal of the gearbox when the motor and gearbox are matched. It provides a solution that can effectively solve the problems of insufficient cooling caused by oil seal wear and leakage in oil-cooled motors and oil leakage caused by oil entering the motor and damaging the insulation system when the motor and gearbox are matched. This improves the service life and reliability of the motor. At the same time, the practicality, maintainability and cost of the solution need to be considered to meet the actual application requirements.

[0028] 2. In the above-described solution of the present invention, the main part of the oil return structure is designed to include an oil-throwing structure and a negative pressure structure. The cooperation of the oil-throwing structure and the negative pressure structure enables the oil leaking from the oil seal structure to be effectively returned to the motor or gearbox, realizing the recycling of oil and improving the overall efficiency of the system. Specifically, a negative pressure section located at the rear end of the oil seal structure inside the housing and an oil-throwing section located at the front end of the oil seal structure inside the housing are provided on the rotating shaft. An oil-throwing structure is provided corresponding to the oil-throwing section. The oil-throwing structure includes an oil collecting chamber and a reverse oil-throwing ring. The oil collecting chamber is connected to the interior of the inner oil chamber through an oil return hole. The reverse oil slinger ring is coaxially mounted on the rotating shaft. The rotation of the rotating shaft synchronously drives the reverse oil slinger ring to rotate and sling oil. A negative pressure structure is set in the corresponding negative pressure section. The negative pressure structure includes a negative pressure double impeller and a one-way vent valve. The negative pressure double impeller is coaxially mounted on the negative pressure section and is set close to the oil return hole. A negative pressure chamber is formed at the position of the negative pressure double impeller close to the oil return hole. The one-way vent valve is connected to the negative pressure chamber. The rotation of the rotating shaft synchronously drives the negative pressure double impeller to rotate. The negative pressure double impeller generates negative pressure in the negative pressure chamber near the oil return hole, thereby quickly and effectively returning the oil in the oil collection chamber to the motor or gearbox.

[0029] 3. In the above-described solution of the present invention, considering the characteristic that the higher the speed of the oil-cooled motor and the transmission, the more severe the oil leakage, the oil slinger structure is set at the front end of the oil seal structure, and the negative pressure structure is set at the rear end of the oil seal structure. Combined with the one-way vent valve, this achieves the following effects: First, the negative pressure generated at the rear end of the oil seal structure slows down oil leakage; second, the higher the speed, the greater the negative pressure, accelerating the return flow of oil in the oil collecting chamber; third, before the oil in the oil collecting chamber reaches the lower end of the return oil hole, the higher the impeller speed, the greater the negative pressure. The oil return hole is connected to the outside air. The airflow goes from the outside to the negative pressure zone and then to the one-way vent valve to be discharged, forming an effective circulation. After the oil in the oil collection chamber reaches the lower end of the oil return hole, the higher the impeller speed, the greater the negative pressure generated. Oil returns from the lower part of the oil return hole, while the upper part is still connected to the outside air. The airflow goes from the outside to the negative pressure zone and then to the one-way vent valve to be discharged, forming an effective circulation. The one-way vent valve can precisely control the direction of oil flow, ensuring the smooth progress of the oil return process and avoiding the problem of oil backflow, further improving the sealing performance and reliability of the system.

[0030] 4. In the above-mentioned solution of the present invention, the rotation of the reverse oil slinger ring and the negative pressure double impeller is driven by the rotating shaft. The blades of the negative pressure double impeller can automatically adjust the negative pressure intensity according to the change of motor speed. The negative pressure chamber can be formed inside the casing. The oil collection chamber is also reasonably set. The oil return structure design is simple and reasonable, easy to manufacture and install. Compared with the traditional sealing structure, it has better practicality and economy, and has strong adaptability. It can maintain a stable sealing effect under different speed and temperature conditions.

[0031] 5. In the above-described solution of the present invention, when the motor and gearbox are running, the rotating shaft drives the reverse oil-throwing ring and the negative pressure double impeller to rotate. The reverse oil-throwing ring throws the oil leaking from the oil seal structure into the oil collection chamber facing the rear end. The rotation of the negative pressure double impeller forms a negative pressure path towards the inner oil chamber in the negative pressure chamber and the oil return hole. After the second oil level is higher than the oil return hole, the oil in the oil collection chamber enters the inner oil chamber through the negative pressure path. The rotation of the negative pressure double impeller generates negative pressure, and the rotation of the reverse oil-throwing ring throws the oil leaking from the oil seal structure into the oil collection chamber facing the rear end. The oil in the oil collection chamber enters the inner oil chamber through the negative pressure path. This reasonable and ingenious fluid dynamics design of airflow + liquid flow effectively solves the oil leakage problem when the oil-cooled motor and gearbox are connected, significantly improves the service life and reliability of the equipment, and has important practical value. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the structure of an embodiment of the present invention; Figure 2 This is a schematic diagram (II) illustrating the working principle of an embodiment of the present invention. Figure 3 This is a three-dimensional schematic diagram of the motor according to an embodiment of the present invention (view 1); Figure 4 This is a three-dimensional schematic diagram of the motor according to an embodiment of the present invention (viewpoint two); Figure 5 This is a cross-sectional schematic diagram of the motor according to an embodiment of the present invention (viewpoint 1); Figure 6 This is a cross-sectional schematic diagram of the motor according to an embodiment of the present invention (viewpoint two); Figure 7 This is a cross-sectional schematic diagram of the motor according to an embodiment of the present invention (viewpoint three); Figure 8 This is a three-dimensional schematic diagram of the oil-slinging structure in an embodiment of the present invention (view 1); Figure 9 This is a three-dimensional schematic diagram (view 2) of the oil-slinging structure in an embodiment of the present invention. Figure 10 This is a front view of the oil-slinging structure in an embodiment of the present invention; Figure 11 for Figure 10 Schematic diagram of AA section in the middle; Figure 12 This is a schematic diagram of the reverse oil-throwing ring in an embodiment of the present invention.

[0033] The parts shown in the above attached diagram are illustrated below: 1. Housing; 11. Inner oil cavity; 12. First oil level; 2. Shaft; 21. Negative pressure section; 22. Oil slingering section; 3. Oil seal structure; 4. Oil-slinging structure; 41. Oil collecting chamber; 410. Second oil level surface; 411. Opening; 42. Reverse oil slinger ring; 421. First curved section; 422. Second curved section; 423. Guide groove; 43. Oil return hole; 5. Negative pressure structure; 50. Negative pressure chamber; 51. Negative pressure double impeller; 52. One-way vent valve. Detailed Implementation

[0034] The present invention will be clearly described below with illustrations and detailed description. Any person skilled in the art who understands the embodiments of the present invention can make changes and modifications based on the technology taught in the present invention without departing from the spirit and scope of the present invention.

[0035] This invention aims to solve the problems in the prior art where oil-cooled motors suffer from insufficient cooling due to wear and leakage of the oil seal, and where the transmission oil seal is prone to wear and leakage during the motor-transmission connection, resulting in damage to the motor's insulation system. To address the urgent need for a solution that effectively solves the problems of insufficient cooling caused by wear and leakage of the oil seal in oil-cooled motors and the damage to the insulation system caused by oil entering the motor due to leakage during the motor-transmission connection, this invention presents an oil return structure and a device employing this oil return structure.

[0036] Example 1, as shown in the appendix Figure 1 To be continued Figure 12 As shown, Embodiment 1 of the present invention discloses an oil return structure for oil return from the motor and gearbox in an electric motor-gearbox assembly. The motor and gearbox have a sealed cavity at their mating point. Both the motor and gearbox have a housing 1 and a rotating shaft 2. The housing 1 has an inner oil cavity 11 with a first oil level surface 12. The rotating shaft 2 is provided with an oil seal structure 3 for sealing the opening of the inner oil cavity 11. The oil return structure includes: The negative pressure section 21 and the oil-slinging section 22 are provided on the rotating shaft 2. The negative pressure section 21 is located at the rear end of the oil seal structure 3 inside the housing 1, and the oil-slinging section 22 is located at the front end of the oil seal structure 3.

[0037] An oil-throwing structure 4 is provided on the housing 1 and corresponding to the oil-throwing section 22. The oil-throwing structure 4 includes an oil collecting chamber 41 and a reverse oil-throwing ring 42. The oil collecting chamber 41 is connected to the interior of the inner oil chamber 11 through an oil return hole 43. The oil collecting chamber 41 has a second oil level surface 410. The reverse oil-throwing ring 42 is coaxially mounted on the rotating shaft 2. The oil-throwing part at the rear end of the reverse oil-throwing ring 42 extends into the oil collecting chamber 41.

[0038] A negative pressure structure 5 is provided on the housing 1 and corresponding to the negative pressure section 21. The negative pressure structure 5 includes a negative pressure double impeller 51 and a one-way vent valve 52. The negative pressure double impeller 51 is coaxially mounted on the negative pressure section 21 and is located near the oil return hole 43. A negative pressure chamber 50 is formed on the negative pressure double impeller 51 near the oil return hole 43. The one-way vent valve 52 is located on the housing 1 above the middle of the double impellers of the negative pressure double impeller 51.

[0039] The oil return structure is configured such that, in at least one fixed position of the motor and the gearbox, the oil return hole 43 is located above the first oil level 12. When the motor and the gearbox are running, the rotating shaft 2 drives the reverse oil slinger ring 42 and the negative pressure double impeller 51 to rotate. The reverse oil slinger ring 42 throws the oil leaking from the oil seal structure 3 into the oil collection chamber 41 facing the rear end. The rotation of the negative pressure double impeller 51 forms a negative pressure path towards the inner oil chamber 11 in the negative pressure chamber 50 and the oil return hole 43. After the second oil level 410 is higher than the oil return hole 43, the oil in the oil collection chamber 41 enters the inner oil chamber 11 through the negative pressure path.

[0040] like Figure 2 As shown, the working process of Embodiment 1 of the present invention can be referred to as follows: When the motor and gearbox are running, the rotating shaft 2 drives the reverse oil slinger ring 42 and the negative pressure double impeller 51 to rotate. Oil seeps out from the oil seal structure 3, and the seeping oil flows along the rotating shaft 2 to the reverse oil throwing ring 42. The reverse oil throwing ring 42 rotates at high speed in the oil collecting chamber 41, throwing the seeping oil into the oil collecting chamber 41 facing the rear end. The negative pressure double impeller 51 rotates at high speed inside the housing 1, creating a negative pressure environment in the negative pressure chamber 50 near the oil return hole 43. This draws the oil from the oil collection chamber 41 and returns it to the inner oil chamber 11, thus achieving oil recycling. The blades of the negative pressure double impeller 51 can automatically adjust the negative pressure intensity according to the change in motor speed to ensure the oil return effect.

[0041] Through the implementation of the above embodiment 1 of the present invention, the main part of the oil return structure is designed to include an oil-throwing structure 4 and a negative pressure structure 5. The cooperation of the oil-throwing structure 4 and the negative pressure structure 5 enables the oil leaking from the oil seal structure 3 to be effectively returned to the motor or gearbox, realizing the recycling of oil and improving the overall efficiency of the system. Specifically, a negative pressure section 21 located at the rear end of the oil seal structure 3 inside the housing 1 and an oil-throwing section 22 located at the front end of the oil seal structure 3 inside the housing 1 are provided on the rotating shaft 2. An oil-throwing structure 4 is provided corresponding to the oil-throwing section 22. The oil-throwing structure 4 includes an oil collecting chamber 41 and a reverse oil-throwing ring 42. The oil collecting chamber 41 is connected to the interior of the inner oil chamber 11 through an oil return hole 43, and the reverse oil-throwing ring... The 42 is coaxially mounted on the rotating shaft 2. The rotation of the rotating shaft 2 synchronously drives the reverse oil-throwing ring 42 to rotate and throw oil. A negative pressure structure 5 is set corresponding to the negative pressure section 21. The negative pressure structure 5 includes a negative pressure double impeller 51 and a one-way vent valve 52. The negative pressure double impeller 51 is coaxially mounted on the negative pressure section 21 and is set close to the oil return hole 43. A negative pressure chamber 50 is formed at the position of the negative pressure double impeller 51 close to the oil return hole 43. The one-way vent valve 52 is connected to the negative pressure chamber 50. The rotation of the rotating shaft 2 synchronously drives the negative pressure double impeller 51 to rotate. The negative pressure double impeller 51 generates negative pressure in the negative pressure chamber 50 near the oil return hole 43, thereby quickly and effectively returning the oil in the oil collection chamber 41 to the motor or gearbox.

[0042] Through the implementation of the above-described embodiment 1 of the present invention, addressing the characteristic that oil leakage is more severe at higher speeds in oil-cooled motors and transmissions, the oil slinger structure 4 is positioned at the front end of the oil seal structure 3, and the negative pressure structure 5 is positioned at the rear end of the oil seal structure 3. Combined with the one-way vent valve 52, the following effects are achieved: First, the negative pressure generated at the rear end of the oil seal structure 3 slows down oil leakage; second, the higher the speed, the greater the negative pressure, accelerating the return flow of oil in the oil collecting chamber 41; third, before the oil in the oil collecting chamber 41 reaches the lower end of the return oil hole 43, the higher the impeller speed, the greater the negative pressure. The oil return hole 43 is connected to the outside air. The airflow goes from the outside to the negative pressure zone and then to the one-way vent valve 52 to be discharged, forming an effective circulation. After the oil in the oil collection chamber 41 reaches the lower end of the oil return hole 43, the higher the impeller speed, the greater the negative pressure generated. The lower part of the oil return hole 43 returns oil, while the upper part is still connected to the outside air. The airflow goes from the outside to the negative pressure zone and then to the one-way vent valve 52 to be discharged, forming an effective circulation. The one-way vent valve 52 can be set to precisely control the direction of oil flow, ensuring the smooth progress of the oil return process and avoiding the problem of oil backflow, further improving the sealing performance and reliability of the system.

[0043] Through the implementation of the above-described embodiment 1 of the present invention, the rotation of the reverse oil slinger ring 42 and the negative pressure double impeller 51 is driven by the rotating shaft 2. The negative pressure chamber 50 can be formed inside the housing 1. The setting of the oil collecting chamber 41 is also very reasonable. The oil return structure design is simple and reasonable, easy to manufacture and install. Compared with the traditional sealing structure, it has better practicality and economy, and at the same time has strong adaptability, maintaining a stable sealing effect under different speed and temperature conditions. When the motor and gearbox are running, the rotating shaft 2 drives the reverse oil slinger ring 42 and the negative pressure double impeller 51 to rotate. The reverse oil slinger ring 42 throws the oil leaking from the oil seal structure 3 into the oil collecting chamber 41 at the rear end. The negative pressure double impeller 51... The rotation of the impeller 51 creates a negative pressure path towards the inner oil cavity 11 in the negative pressure chamber 50 and the return oil hole 43. After the second oil level 410 is higher than the return oil hole 43, the oil in the oil collection chamber 41 enters the inner oil cavity 11 through the negative pressure path. The rotation of the negative pressure double impeller 51 generates negative pressure, and the rotation of the reverse oil throwing ring 42 throws the oil leaking from the oil seal structure 3 towards the rear end of the oil collection chamber 41. The oil in the oil collection chamber 41 enters the inner oil cavity 11 through the negative pressure path. This reasonable and ingenious design of airflow + liquid flow effectively solves the oil leakage problem when the oil-cooled motor and the gearbox are connected, significantly improves the service life and reliability of the motor, and has important practical value.

[0044] In Embodiment 1 of the present invention, as Figure 8As shown, the oil collecting chamber 41 is fixedly installed at the front end of the housing 1. The oil collecting chamber 41 has an opening 411 for passing through the rotating shaft 2 and the reverse oil slinger ring 42. The inner diameter of the opening 411 is larger than the outer diameter of the reverse oil slinger ring 42. This design makes the structure of the oil slinger structure 4 more reasonable, so that there will be no interference when the reverse oil slinger ring 42 rotates quickly.

[0045] In Embodiment 1 of the present invention, with at least one of the motor and gearbox fixed in place, the lower part of the opening 411 is higher than the horizontal position of the oil return hole 43, and the bottom position inside the oil collecting chamber 41 is lower than the horizontal position of the oil return hole 43. This design ensures that the second oil level 410 in the oil collecting chamber 41 is always lower than the lower part of the opening 411, thereby avoiding the possibility of oil seeping out from the opening 411 in extreme cases and making the oil return process more reasonable.

[0046] In Embodiment 1 of the present invention, the oil return hole 43 is inclined, and one end of the oil return hole 43 is lower than one end of the middle oil collecting chamber 41 in the negative pressure chamber 50. That is, along the radial direction of the rotating shaft 2, the rear end opening of the oil return hole 43 is closer to the axis of the rotating shaft 2 than the front end opening. When the front end opening of the oil return hole 43 is set at a lower position of the second oil level surface 410, the height of the rear end opening is lower than the height of the front end opening, so that the oil can flow more smoothly into the inner oil chamber 11 of the housing 1. During the downward flow of the oil, negative pressure is generated. When the rotating shaft 2 stops running, the oil in the oil collecting chamber 41 can also be smoothly drawn into the inner oil chamber 11. This design also has another function, that is, when the new energy vehicle is on a single-sided inclined road section, the tilt of the motor will not cause the oil in the first oil level surface 12 on the inner oil chamber 11 of the housing 1 to backflow out from the oil return hole 43, thereby ensuring that the new energy vehicle using this oil return structure has good stability and reliability on various road surfaces and under various conditions.

[0047] In Embodiment 1 of the present invention, the inner wall of the oil collecting chamber 41 is provided with an anti-corrosion coating to prevent corrosion by oil, improve the service life of the oil return structure, and reduce the maintenance cycle of the motor or gearbox.

[0048] In Embodiment 1 of the present invention, as Figure 9 , Figure 11 As shown, the inner side of the oil-throwing part of the reverse oil-throwing ring 42 is provided with a plurality of guide grooves 423 for oil flow. The guide grooves 423 are radially and evenly distributed. This radially and evenly distributed guide groove design is conducive to the rapid throwing out of the oil. In conjunction with the rapid rotation of the reverse oil-throwing ring 42 following the rotating shaft 2, the oil can be thrown into the oil collection chamber 41 as soon as possible, thus accelerating the oil circulation.

[0049] In Embodiment 1 of the present invention, as Figure 12As shown, the oil-throwing section of the reverse oil-throwing ring 42 has a first curved section 421 and a second curved section 422 from front to back. The first curved section 421 is located on the front side of the oil collecting chamber 41, and the second curved section 422 is located on the inner side of the oil collecting chamber 41. The distance between part of the second curved section 422 and the central axis of the rotating shaft 2 is less than the distance between the first curved section 421 and the central axis of the rotating shaft 2. With this design, the inner diameter of part of the first curved section 421 is larger than the inner diameter of the second curved section 422. After the oil seeping out of the rotating shaft 2 is blocked by the reverse oil-throwing ring 42, the oil is thrown from the front end to the rear end. When flowing from the first curved section 421 to the second curved section 422, due to the decrease in inner diameter and the change in centrifugal force, the oil is more effectively thrown towards the inner wall of the oil collecting chamber 41 under the action of centrifugal force. Moreover, this hyperbolic setting also makes the space occupied by the reverse oil-throwing ring 42 smaller, and it can be set more compactly. At the same time, this structure, combined with the radially and evenly distributed guide grooves 423, can effectively improve the oil-throwing effect, enhance the local structural strength, and extend the service life of the reverse oil-throwing ring 42.

[0050] In Embodiment 1 of the present invention, the negative pressure double impeller adopts a double impeller structure. During the operation of the motor, the forward and reverse rotation of the shaft 2 will generate negative pressure at the oil return hole 43, thereby stably providing negative pressure and ensuring the orderly return of oil.

[0051] In Embodiment 1 of the present invention, the one-way vent valve 52 is installed on the housing 1 above the middle of the two impellers of the negative pressure double impeller 51. A negative pressure chamber 50 is formed inside the housing 1. The one-way vent valve 52 is located above the negative pressure chamber 50 and can directly connect the excessive negative pressure generated in the negative pressure chamber 50 to the outside atmosphere. The one-way vent valve 52 can only release air from the inside and cannot release air from the outside. It is used to create negative pressure in the oil return hole 43 and control the flow direction of the oil.

[0052] Example 2: This invention proposes a device that includes a motor and a gearbox assembly, and has a sealed cavity at the mating point of the motor and the gearbox, and the sealed cavity is provided with an oil return structure as described in Example 1 of this invention.

[0053] Through the implementation of Embodiment 2 of the present invention, a more practical, easier to maintain, and lower-cost solution is adopted, which effectively solves the problems of insufficient cooling caused by oil seal wear and leakage in oil-cooled motors and oil leakage during the operation of motor and gearbox causing oil to enter the motor and damage the insulation system. This effectively improves the service life and reliability of the motor, thereby increasing the overall reliability and safety of the equipment.

[0054] The technical solution of the present invention will now be described in detail with reference to one specific embodiment.

[0055] In this detailed embodiment, a device is disclosed, which is equipped with an oil-cooled motor and a gearbox. The mating part of the oil-cooled motor and the gearbox has a sealed cavity. An oil return structure is provided in the sealed cavity of the oil-cooled motor and the gearbox. The oil-cooled motor includes a housing 1 and a rotating shaft 2. The housing 1 has an inner oil cavity 11. The inner oil cavity 11 has a first oil level surface 12. The rotating shaft 2 is provided with an oil seal structure 3 for sealing the opening of the inner oil cavity 11.

[0056] In this detailed embodiment, the oil return structure includes: The negative pressure section 21 and the oil-slinging section 22 are provided on the rotating shaft 2. The negative pressure section 21 is located at the rear end of the oil seal structure 3 inside the housing 1, and the oil-slinging section 22 is located at the front end of the oil seal structure 3.

[0057] An oil-slinging structure 4 is provided on the housing 1 and corresponding to the oil-slinging section 22. The oil-slinging structure 4 includes an oil collecting chamber 41 and a reverse oil-slinging ring 42. The inner wall of the oil collecting chamber 41 is provided with an anti-corrosion coating. The oil collecting chamber 41 is fixedly provided at the front end of the housing 1. The oil collecting chamber 41 has an opening 411 for the shaft 2 and the reverse oil-slinging ring 42 to pass through. The inner diameter of the opening 411 is larger than the outer diameter of the reverse oil-slinging ring 42. The lower part of the opening 411 is higher than the horizontal position of the oil return hole 43. The bottom position inside the oil collecting chamber 41 is lower than the horizontal position of the oil return hole 43. The oil collecting chamber 41 is connected to the inner oil chamber 11 through the oil return hole 43. The oil return hole 43 is inclined and is located in the negative pressure chamber 50. The end of the oil collection chamber 41 is lower than the middle oil collection chamber 41. The oil collection chamber 41 has a second oil level surface 410. The reverse oil slinger ring 42 is coaxially mounted on the rotating shaft 2. The oil slinger portion of the rear end of the reverse oil slinger ring 42 extends into the oil collection chamber 41. The oil slinger portion of the reverse oil slinger ring 42 has a first curved section 421 and a second curved section 422 from front to back. The first curved section 421 is located on the front side of the oil collection chamber 41, and the second curved section 422 is located on the inner side of the oil collection chamber 41. The distance between part of the second curved section 422 and the central axis of the rotating shaft 2 is less than the distance between the first curved section 421 and the central axis of the rotating shaft 2. The inner side of the oil slinger portion of the reverse oil slinger ring 42 is provided with a plurality of guide grooves 423 for oil flow guidance. The guide grooves 423 are radially and evenly distributed.

[0058] A negative pressure structure 5 is installed on the housing 1 and corresponding to the negative pressure section 21. The negative pressure structure 5 includes a negative pressure double impeller 51 and a one-way vent valve 52. The negative pressure double impeller 51 is coaxially mounted on the negative pressure section 21 and is located near the oil return hole 43. A negative pressure chamber 50 is formed at the position of the negative pressure double impeller 51 near the oil return hole 43. The one-way vent valve 52 is connected to the negative pressure chamber 50. The negative pressure double impeller adopts a double impeller structure. During the operation of the motor, both the forward and reverse rotation of the shaft 2 will generate negative pressure at the oil return hole 43. The one-way vent valve 52 is located on the housing 1 above the negative pressure double impeller 51. A negative pressure chamber 50 is formed inside the housing 1. The one-way vent valve 52 is located on the housing 1 above the middle of the double impellers of the negative pressure double impeller 51.

[0059] In this detailed embodiment, the working principle of this oil return structure applied to oil-cooled motors or gearboxes is as follows: The oil seal structure 3 of the inner oil cavity 11 inside the oil-cooled motor or gearbox is sealed by an oil seal body or a labyrinth seal. The front end of the oil seal body or labyrinth seal is provided with a reverse oil-throwing ring 42, which is used to throw out the oil leaking from the oil seal body or labyrinth seal. The outer periphery of the reverse oil-throwing ring 42 is provided with multiple guide grooves 423 for oil flow. The guide grooves 423 are evenly distributed radially, which is conducive to the rapid throwing out of the oil.

[0060] An oil collecting chamber 41 is formed between the oil seal body or labyrinth seal and the reverse oil throwing ring 42. The oil collecting chamber 41 is used to collect the thrown-out oil. The inner wall of the oil collecting chamber 41 is provided with an anti-corrosion coating to prevent oil corrosion. Multiple oil return holes 43 are provided on the inner wall of the oil collecting chamber 41. The oil return holes 43 are located above the first oil level 12. The number of oil return holes 43 is determined according to actual needs.

[0061] When the motor is running, the negative pressure double impeller 51 rotates at high speed inside the oil return hole 43, creating a negative pressure inside the oil return hole 43. This draws the oil out of the oil collection chamber 41 and returns it to the oil chamber, achieving oil recycling. The blades of the negative pressure double impeller 51 can automatically adjust the negative pressure intensity according to changes in motor speed to ensure effective oil return.

[0062] A one-way vent valve 52 is located on the housing 1 at the top of the negative pressure double impeller 51. The one-way vent valve 52 allows air to flow outwards only, preventing air from flowing inwards. It is used to create negative pressure within the oil return hole 43, controlling the flow direction of the oil. Through this structural design, the present invention achieves oil recycling, effectively solving the problem of oil leakage caused by easy wear of the traditional oil seal structure 3, and greatly improving the service life and reliability of the motor.

[0063] By implementing the above embodiments, the problems of insufficient cooling caused by oil seal wear and leakage in oil-cooled motors and oil leakage during the operation of motor and gearbox causing oil to enter the motor and damage the insulation system can be effectively solved, thereby improving the service life and stability of the motor and achieving the purpose of the present invention.

[0064] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. An oil return structure for oil return from the motor and gearbox in an electric motor-gearbox assembly, wherein the mating area of ​​the motor and gearbox has a sealed cavity, both the motor and gearbox have a housing and a shaft, the housing has an inner oil cavity with a first oil level surface, and the shaft is provided with an oil seal structure for sealing the opening of the inner oil cavity, characterized in that, The oil return structure includes: The negative pressure section and the oil slinger section are located on the rotating shaft. The negative pressure section is located at the rear end of the oil seal structure inside the housing, and the oil slinger section is located at the front end of the oil seal structure. An oil-slinging structure is provided on the housing and corresponding to the oil-slinging section. The oil-slinging structure includes an oil collecting chamber and a reverse oil-slinging ring. The oil collecting chamber is connected to the interior of the inner oil chamber through an oil return hole. The oil collecting chamber has a second oil level surface. The reverse oil-slinging ring is coaxially mounted on the rotating shaft. The oil-slinging part at the rear end of the reverse oil-slinging ring extends into the oil collecting chamber. A negative pressure structure is provided on the casing and corresponding to the negative pressure section. The negative pressure structure includes a negative pressure double impeller and a one-way vent valve. The negative pressure double impeller is coaxially installed on the negative pressure section and is located near the oil return hole. A negative pressure chamber is formed at the position of the negative pressure double impeller near the oil return hole. The one-way vent valve is located on the casing above the middle of the double impellers of the negative pressure double impeller. The oil return structure is configured such that it is located in the sealed cavity at the junction of the motor and the gearbox. In at least one fixed position of the motor and the gearbox, the oil return hole is located above the first oil level. When the motor and the gearbox are running, the shaft drives the reverse oil slinger ring and the negative pressure double impeller to rotate. The reverse oil slinger ring throws the oil leaking from the oil seal structure into the oil collection chamber at the rear end. The rotation of the negative pressure double impeller forms a negative pressure path towards the inner oil chamber in the negative pressure chamber and the oil return hole. After the second oil level is higher than the oil return hole, the oil in the oil collection chamber enters the inner oil chamber through the negative pressure path.

2. The oil return structure according to claim 1, characterized in that: The oil collecting chamber is fixedly disposed at the front end of the housing. The oil collecting chamber has an opening for the shaft and the reverse oil slinger ring to pass through. The inner diameter of the opening is larger than the outer diameter of the reverse oil slinger ring.

3. The oil return structure according to claim 2, characterized in that: With at least one of the motor and gearbox in a fixed position, the lower part of the opening is higher than the horizontal position of the oil return hole, and the bottom position inside the oil collecting chamber is lower than the horizontal position of the oil return hole.

4. The oil return structure according to claim 1, characterized in that: The oil return hole is inclined, with one end of the oil return hole in the negative pressure chamber lower than one end of the central oil collection chamber.

5. The oil return structure according to claim 1, characterized in that: The inner wall of the oil collecting chamber is provided with an anti-corrosion coating.

6. The oil return structure according to claim 1, characterized in that: The inner side of the oil-throwing section of the reverse oil-throwing ring is provided with multiple guide grooves for oil flow, and the guide grooves are evenly distributed radially.

7. The oil return structure according to claim 1 or 6, characterized in that: The oil-slinging part of the reverse oil-slinging ring has a first curved section and a second curved section from front to back. The first curved section is located on the front side of the oil collecting chamber, and the second curved section is located on the inner side of the oil collecting chamber. The distance between a portion of the second curved section and the central axis of the rotating shaft is less than the distance between the first curved section and the central axis of the rotating shaft.

8. The oil return structure according to claim 1, characterized in that: The negative pressure double impeller adopts a double impeller structure. During the operation of the motor, both the forward and reverse rotation of the shaft will generate negative pressure at the oil return hole.

9. A device, characterized in that: The device includes a motor and a gearbox assembly, and the mating part of the motor and gearbox has a sealed cavity, in which an oil return structure as described in any one of claims 1 to 8 is provided.

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