A motor cooling structure and method integrating oil cooling and air cooling for rotating shaft heat dissipation

Abstract

The application discloses a motor cooling structure and method integrating oil cooling and air cooling of a rotating shaft, and belongs to the technical field of motor cooling, which comprises a rotating shaft assembly, a rotor assembly, a stator assembly, a casing, an end cover assembly, a bearing assembly, an air cooling and heat dissipation assembly and a sealing assembly; the rotating shaft is composed of a first shaft body and a second shaft body which are sealingly connected, and is internally integrated with an oil cooling circulation channel, and is provided with a throttling hole, an elastic valve plate and a cavity with a helical flow guide groove on an inner wall; a W-shaped air duct is arranged on the outer wall of the casing in the axial direction. When cooling, the cooling oil is injected and then divided into two paths, one of which flows along the helical groove in the cavity to heat-exchange and cool the rotor, and the other of which is discharged after the flow is self-adaptively adjusted by the elastic valve plate; the rotating shaft drives the air cooling assembly to drive airflow to pass through the W-shaped air duct to forcibly convection cool the stator. The application realizes partitioned and composite heat dissipation, can self-adaptively adjust the oil amount according to the working condition, improves the heat dissipation efficiency and operation stability, has high structural integration degree, and is suitable for high-power-density motors.

Description

Technical Field

[0001] This invention relates to the field of motor cooling technology, and in particular to a motor cooling structure and cooling method that integrates shaft oil cooling and air cooling. Background Technology

[0002] As motor equipment rapidly develops towards higher power density, higher speed, and smaller size, the heat generated by copper loss, iron loss, and mechanical friction loss during motor operation increases significantly. If the heat cannot be dissipated in a timely and efficient manner, it will cause a series of problems such as accelerated aging of winding insulation, demagnetization of permanent magnets, and shortened bearing life, which will seriously restrict the output performance and operational reliability of the motor.

[0003] Currently, conventional motor cooling methods are mainly divided into two categories: air cooling and oil cooling. Both methods have obvious technical limitations: pure air cooling structures mostly rely on fans blowing directly onto the outer wall of the casing, which has problems such as short airflow paths, limited heat exchange area, and poor heat dissipation uniformity. It can only meet the heat dissipation needs of low-power, low-load motors, and cannot quickly remove the high-temperature heat accumulated in the stator components for high-power motors. Pure oil cooling structures mostly adopt shell spray cooling or external oil circuit circulation cooling mode. The cooling oil cannot directly contact the core heat-generating area of ​​the rotor, resulting in a large heat dissipation blind area inside the rotor. In addition, the overall oil circuit structure is complex, the production and assembly costs are high, and it is easy to waste cooling oil resources.

[0004] Existing composite cooling motors are mostly simple superpositions of air-cooled and oil-cooled structures, without matching dedicated heat dissipation structures to the different heat generation characteristics of the rotor and stator. The oil cooling oil circuit diversion design is unreasonable, and the cooling oil flow state cannot be adaptively adjusted according to the motor load conditions. At the same time, the internal air duct structure of the housing is simple, and the airflow is prone to turbulence and short circuits. The oil cooling system and the air cooling system cannot form a synergistic heat dissipation effect, resulting in low overall heat dissipation efficiency and difficulty in meeting the long-term stable operation requirements of high-power, high-density motors. Summary of the Invention

[0005] The purpose of this invention is to provide a motor cooling structure and method that integrates shaft oil cooling and air cooling. It adopts a composite heat dissipation mode of rotor built-in split oil cooling and stator external forced air cooling to achieve precise heat dissipation in hot and cold zones. At the same time, it relies on an adaptive oil pressure regulating oil circuit structure to adapt to different operating conditions of the motor, thereby improving the overall heat dissipation uniformity and operating stability of the motor.

[0006] To achieve the above objectives, the present invention provides a motor cooling structure and method integrating shaft oil cooling and air cooling, comprising a shaft assembly, a rotor assembly, a stator assembly, a housing, an end cover assembly, a bearing assembly, an air cooling assembly, and a sealing assembly; the rotor assembly is fixed to the outside of the shaft assembly, the stator assembly is fixedly installed inside the housing and arranged around the rotor assembly, with a motor air gap reserved between them; the end cover assembly is sealed and fixed to both ends of the housing, the bearing assembly is installed between the end cover assembly and the shaft assembly to support the rotation of the shaft assembly; the air cooling assembly is installed at the end of the shaft assembly, and the sealing assembly covers the outside of the housing and the air cooling assembly.

[0007] Preferably, the shaft assembly includes a first shaft and a second shaft that are sealed together, both of which have hollow oil passages inside and are interconnected to form an oil cooling circulation channel; the first shaft has an oil injection hole, an oil inlet channel, an oil inlet hole, a throttling hole, and an elastic valve plate. The oil injection hole is located on the outer wall of the end of the first shaft opposite to the second shaft and communicates with the oil inlet channel. The oil inlet holes are radially distributed and communicate with the oil inlet channel and the interior of the second shaft. The throttling hole is located at the end of the oil inlet channel. The elastic valve plate is mounted on the end of the throttling hole facing the oil outlet side, and is used to regulate the oil flow. The internal oil pressure adaptively completes the opening and closing to regulate the oil flow rate; the second shaft body has a cavity inside, and the inner wall of the cavity is surrounded by a spiral guide groove, which extends axially to both ends of the cavity. The second shaft body also has an oil outlet channel communicating with the throttling orifice and oil outlet holes distributed radially; the outer wall of the housing is provided with a W-shaped air duct along the axial direction. The W-shaped air duct is composed of a continuous W-shaped corrugated structure, and its two ends pass through the assembly surfaces at both ends of the housing; the oil cooling circulation channel and the air cooling heat dissipation assembly work together to perform zoned heat dissipation on the rotor side and the stator side respectively.

[0008] Preferably, the cavity gradually increases in diameter from the middle symmetrical position to both ends, forming a symmetrical conical slope; the spiral direction of the spiral guide groove is consistent with the working rotation direction of the rotating shaft, and its groove depth and pitch gradually increase from the middle of the cavity to both ends, with the spiral helix angle set to 30° to 60°.

[0009] Preferably, the diameter of the throttling orifice is smaller than the diameter of the oil inlet channel; the elastic valve plate is a thin metal sheet with elasticity, one end of which is fixed to the inner wall of the oil inlet channel, and the other end freely covers the throttling orifice; when the oil pressure inside the oil circuit is higher than a preset threshold, the elastic valve plate undergoes elastic deformation to open, increasing the oil flow rate; when the oil pressure is lower than the preset threshold, the elastic valve plate resets and blocks the throttling orifice, reducing the oil flow rate.

[0010] Preferably, the oil outlet channel includes a first oil outlet channel and a second oil outlet channel, the outlet ends of which are located at the end of the second shaft opposite to the first shaft, and the cooling oil is directly sprayed to the outside of the second shaft through the oil outlet hole.

[0011] Preferably, the end cap assembly is detachably fixed to both ends of the housing through positioning holes, and sealing gaskets are fitted at the joint gap between the two; the bearing assembly includes two sets of bearings, which are respectively embedded and fixed in the central mounting holes of the end cap assemblies at both ends, the inner rings of the bearings are interference-fitted with the first shaft and the second shaft respectively, and the outer rings of the bearings are interference-fitted with the end cap assembly, together bearing the radial load and axial load of the shaft assembly and the rotor assembly.

[0012] Preferably, the air-cooled heat dissipation component is a centrifugal fan, which is fixedly assembled to the end of the second shaft away from the first shaft by a keyway and a flat key, and rotates synchronously with the shaft; the sealing component forms an annular air cavity between itself and the housing, and the fan blade outlet faces the annular air cavity, which is used to radially throw air into the W-shaped air duct.

[0013] Preferably, the crest of the W-shaped air duct fits into the outer wall of the casing, and the trough forms an airflow channel between the trough and the outer wall of the casing; the inner wall of the air duct is mirror-polished, and large rounded corners are provided at the corners to reduce wind resistance and balance the airflow of each parallel branch.

[0014] Preferably, the sealing assembly includes a sealing cover, a sealing cap, and a protective mesh; the sealing cover is installed along the boss of the housing for sealing, the sealing cap is detachably installed at the end of the sealing cover and its position corresponds to the air-cooled heat dissipation assembly, and the protective mesh is set at the air inlet of the sealing cap for filtering dust and impurities in the outside air.

[0015] This invention also discloses a motor cooling method integrating shaft oil cooling and air cooling, comprising the following steps: S1. Cooling oil injection and distribution steps: Cooling oil is injected through the oil injection hole on the first shaft. After being transported through the oil inlet channel, the cooling oil is divided into two paths. One path enters the cavity of the second shaft through the oil inlet hole, and the other path enters the oil outlet channel after passing through the throttle hole and adaptively adjusting the opening through the elastic valve plate. S2. Rotary shaft oil cooling heat dissipation steps: The cooling oil entering the cavity flows spirally towards both ends of the cavity along the spiral guide groove under the action of centrifugal force generated by the rotation of the shaft, and exchanges heat with the inner wall of the cavity to remove the heat of the rotor assembly and the shaft; the cooling oil entering the oil outlet channel is discharged through the oil outlet hole, removing the heat of the shaft core area. S3. Stator air-cooling heat dissipation steps: The rotating shaft drives the air-cooling heat dissipation components to rotate synchronously, drawing in external air and pressurizing it before sending it into the W-shaped air duct of the casing. The airflow flows along the W-shaped air duct and undergoes forced convection heat exchange with the outer wall of the casing. The hot air after heat exchange is discharged to the outside, completing the air-cooling cooling of the stator components.

[0016] Therefore, the present invention employs the above-mentioned integrated shaft oil cooling and air cooling heat dissipation motor cooling structure and cooling method, which has the following technical effects: (1) The present invention adopts a composite heat dissipation architecture of internal oil cooling and external air cooling, which is adapted to the heating characteristics of rotor and stator. It uses the built-in oil circuit to directly contact the heating core of rotor, which solves the problem of large blind area of ​​traditional oil-cooled rotor heat dissipation. Combined with the W-shaped air duct of the casing to increase the heat exchange area of ​​airflow on the stator side, it achieves bidirectional synchronous heat dissipation. Compared with the traditional single heat dissipation structure, the heat dissipation efficiency is significantly improved, which can effectively adapt to the long-term operating conditions of high-power heavy-load motors.

[0017] (2) The present invention adopts a purely mechanical passive valve structure composed of a throttling orifice and an elastic valve plate, which can automatically adjust the cooling oil flow rate according to the oil pressure fluctuation caused by the change of rotation speed. When the motor is at low speed and light load, the oil circulation is reduced and the oil stirring loss is reduced. When the motor is at high speed and heavy load, the flow rate is automatically increased to enhance heat dissipation, taking into account both heat dissipation performance and operating economy, and adapting to the needs of multiple working conditions.

[0018] (3) The present invention provides a spiral guide groove on the inner wall of the cavity, which forces the cooling oil to flow in a spiral along the inner wall, destroys the fluid thermal boundary layer, extends the heat exchange path, and significantly improves the oil side heat transfer coefficient; the conical slope combined with centrifugal force realizes the uniform axial distribution of oil, which not only ensures the uniformity of rotor heat dissipation, but also effectively improves the dynamic balance performance under high speed rotation.

[0019] (4) The W-shaped air duct of the present invention achieves the dual effects of increasing the heat dissipation area and inducing turbulence to enhance heat transfer through the continuous corrugated structure. The airflow is attached to the wall without short circuit, and the stator heat dissipation is more uniform. The mirror polishing of the inner wall of the air duct and the large rounded corner transition design effectively reduce wind resistance and improve airflow utilization.

[0020] (5) The present invention integrates the oil circuit into the inside of the rotating shaft and the air circuit into the space between the housing and the sealing cover. There is no need for an external oil pump and an independent fan motor. The overall structure is compact and the components are highly integrated. The multiple sealing and protection structures improve the reliability of motor operation. The detachable sealing cover design facilitates the maintenance and replacement of the air-cooled heat dissipation components.

[0021] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0022] Figure 1 This is an overall axial sectional view of a motor cooling structure integrating shaft oil cooling and air cooling according to the present invention. Figure 2 This is an axial sectional view of the second shaft of a motor cooling structure integrating oil cooling and air cooling of the rotating shaft according to the present invention. Figure 3 This is a right-side structural schematic diagram of the housing of a motor cooling structure integrating shaft oil cooling and air cooling according to the present invention. Figure 4 This is an axial cross-sectional view of the W-shaped air duct of the housing of a motor cooling structure integrating shaft oil cooling and air cooling heat dissipation according to the present invention. Figure 5 This is a right-side structural schematic diagram of a motor cooling structure sealing assembly integrating shaft oil cooling and air cooling according to the present invention. Figure 6 This is a right-side structural schematic diagram of the air-cooled heat dissipation component of a motor cooling structure integrating shaft oil cooling and air cooling according to the present invention. Figure 7 This is a right-side structural schematic diagram of the end cover assembly of a motor cooling structure integrating shaft oil cooling and air cooling according to the present invention.

[0023] Figure Labels 1. First shaft; 2. Second shaft; 3. Rotor assembly; 4. Stator assembly; 5. End cover assembly; 6. Housing; 7. Bearing assembly; 8. Air-cooled heat dissipation assembly; 9. Sealing assembly; 101. Oil injection hole; 102. Oil inlet channel; 103. Oil inlet hole; 104. Throttling hole; 105. Elastic valve plate; 201. First oil outlet channel; 202. Second oil outlet channel; 203. Oil outlet hole; 204. Spiral guide groove; 205. Cavity; 601. W-shaped air duct; 602. Positioning hole; 603. Boss; 801. Keyway; 901. Sealing cover; 902. Sealing cap; 903. Protective net. Detailed Implementation

[0024] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0025] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0026] like Figures 1 to 7 As shown, a motor cooling structure integrating shaft oil cooling and air cooling is composed of a shaft assembly, a rotor assembly 3, a stator assembly 4, an end cover assembly 5, a housing 6, a bearing assembly 7, an air cooling assembly 8, a sealing assembly 9, and an oil cooling circulation system integrated inside the shaft.

[0027] The shaft assembly consists of a first shaft 1 and a second shaft 2 coaxially sealed together. The mating ends of the two shafts have a stepped fit structure, which can be fixed and sealed by welding or interference fit. Together, they serve as the rotational support and torque transmission components of the motor. The rotor assembly 3 is fixedly fitted to the outer middle of the second shaft 2 by interference fit. The inner diameter of the rotor assembly 3 is completely and tightly fitted with the outer diameter of the second shaft 2. The iron loss and copper loss heat generated by the rotor operation can be directly transferred to the wall of the second shaft 2 through solid heat conduction, and then quickly carried away by the internal cooling oil.

[0028] The stator assembly 4 is press-fitted to the inner wall of the housing 6 and is arranged around the outer side of the rotor assembly 3. A uniform air gap is maintained between the stator assembly 4 and the rotor assembly 3, and there is no contact interference between the moving and stationary parts. The left and right ends of the housing 6 are fixedly connected to the end cover assembly 5 through positioning holes 602, respectively. Sealing gaskets are provided on the contact surfaces of the end cover assembly 5 and the housing 6 to prevent dust and moisture from entering the motor.

[0029] Two sets of bearing assemblies 7 are provided, which are respectively installed in the central mounting holes of the end cap assemblies 5 at both ends. The outer ring of the bearing assembly 7 is interference-fitted with the central hole of the end cap, and the inner ring is fixedly sleeved on the left end of the first shaft 1 and the right end of the second shaft 2 respectively. The two sets of bearings jointly bear the radial and axial loads of the shaft assembly and the rotor assembly 3, ensuring the stable circumferential rotation of the shaft.

[0030] The air-cooled heat dissipation component 8 is installed on the outer end face of the right end cover. The main body is a centrifugal fan. A keyway 801 is opened on the inner wall of the fan hub. The flat key is embedded in the keyway 801 to realize the synchronous transmission of torque between the air-cooled heat dissipation component 8 and the second shaft 2, so that the air-cooled heat dissipation component 8 can rotate synchronously with the second shaft 2 without the need for an additional drive motor.

[0031] The sealing assembly 9 is completely enclosed on the exterior of the housing 6 and the air-cooled heat dissipation assembly 8, and is positioned and sealed by the boss 603 on the housing 6. The sealing assembly 9 consists of three parts: a sealing cover 901, a sealing cap 902, and a protective mesh 903. The sealing cover 901 has an annular vent at its end, the sealing cap 902 has a circular air inlet on its side wall, and the protective mesh 903 is installed outside the air inlet to intercept metal debris and dust particles in the air, preventing impurities from entering the housing 6 with the airflow and damaging the insulation structure of the stator and rotor. The sealing cap 902 adopts a detachable installation structure, and its position corresponds to that of the air-cooled heat dissipation assembly 8. After removal, it can be used as an operating window for fan maintenance and replacement.

[0032] Multiple sets of W-shaped air ducts 601 are evenly distributed along the axial direction on the outer wall of the casing 6. Each set of W-shaped air ducts 601 is arranged close to the outer wall of the casing 6, with its left and right ends extending to the mating surfaces of the casing 6 and the end caps, forming a through-flow airflow channel. The W-shaped air ducts 601 are composed of a continuous W-shaped corrugated structure, with each corrugation containing two peaks and one trough. The peaks are in contact with the outer wall of the casing 6, while the troughs form independent airflow channels between themselves and the outer wall of the casing 6. This structure significantly expands the effective heat dissipation area, and the reciprocating bends of the flow channel force the airflow to constantly change direction, scouring dead corners that conventional straight air ducts cannot cover, disrupting the laminar boundary layer, inducing turbulence generation, and improving the convective heat transfer coefficient. Preferably, the inner wall of the W-shaped air ducts 601 is mirror-polished, and large rounded corners are provided at the corners to eliminate airflow separation and large-area vortex dead zones at right-angle corners, significantly reducing the total airflow resistance of the air ducts and making the flow of each parallel branch more uniform.

[0033] The oil cooling circulation system is fully integrated inside the first shaft 1 and the second shaft 2, including an oil injection hole 101, an oil inlet channel 102, an oil inlet hole 103, a throttle hole 104, an elastic valve plate 105, a first oil outlet channel 201, a second oil outlet channel 202, an oil outlet hole 203, a spiral guide groove 204, and a cavity 205.

[0034] Oil filling hole 101 is located on the outer wall of the end of the first shaft 1 furthest from the second shaft 2, serving as an interface for adding external cooling oil and connecting to an external oil supply system. Oil inlet channel 102 is axially oriented along the axis of the first shaft 1, with one end connected to oil filling hole 101 and the other end extending to the mating position between the first shaft 1 and the second shaft 2. Oil inlet holes 103 are radially distributed on the sidewalls of oil inlet channel 102, connecting oil inlet channel 102 with the cavity 205 inside the second shaft 2, forming the main heat dissipation branch of the rotor.

[0035] A throttling orifice 104 is located at the end of the oil inlet channel 102, and its diameter is smaller than the main diameter of the oil inlet channel 102. An elastic valve plate 105 is a thin, elastic metal sheet that is detachably mounted on the side of the throttling orifice 104 facing the first oil outlet channel 201. One end of the valve plate 105 is fixed to the inner wall of the oil inlet channel 102, and the other end freely covers the throttling orifice 104, forming a unidirectional passive flow regulation structure. When the oil pressure inside the oil circuit is higher than a preset threshold, the oil pressure drives the elastic valve plate 105 to undergo elastic deformation, increasing the opening of the throttling orifice 104 and increasing the cooling oil flow rate. When the oil pressure is lower than the preset threshold, the elastic valve plate 105 resets due to its own elasticity, blocking the throttling orifice 104 and reducing the cooling oil flow rate. This structure can automatically adjust the oil volume according to changes in motor speed and load, achieving low flow rate at low speeds and high flow rate at high speeds, avoiding oil churning losses caused by excessive oil supply at low speeds.

[0036] Cavity 205 is located at the center of the second shaft 2, and its axial length matches the axial width of the rotor assembly 3. The inner wall of cavity 205 is not a uniform diameter structure in the axial direction; instead, its inner diameter gradually increases from the symmetrical center towards both ends, forming a symmetrical conical slope. This design, combined with the centrifugal force of the rotating shaft, guides the cooling oil to diffuse evenly to both ends, preventing oil accumulation in the middle and ensuring uniform axial heat dissipation of the rotor, while also optimizing the dynamic balance performance of the rotor at high speeds. Preferably, the inner wall of cavity 205 is coated with an oleophobic coating. When the shaft stops rotating, this reduces the adhesion of cooling oil to the inner wall of cavity 205, allowing the cooling oil to flow back to the bottom of cavity 205 under gravity, preventing dynamic balance deviations due to uneven oil distribution during the next startup.

[0037] The spiral guide groove 204 is formed around the inner wall of the cavity 205, extending continuously from the center of the cavity 205 to both ends in a spiral shape. Its spiral direction is consistent with the normal operating rotation direction of the motor shaft. The groove depth and pitch of the spiral guide groove 204 gradually increase from the center of the cavity 205 towards both ends as the inner diameter of the cavity 205 increases, with the helix angle set to 30° to 60°. When the shaft rotates, the centrifugal force and the guiding effect of the spiral groove work together to force the cooling oil to flow in a spiral pattern along the inner wall of the cavity 205, significantly extending the contact time between the oil flow path and the wall surface. Simultaneously, the spiral shearing action disrupts the fluid thermal boundary layer, significantly improving the heat transfer coefficient.

[0038] The first oil outlet channel 201 and the second oil outlet channel 202 are located inside the second shaft body 2. The oil inlet end of the first oil outlet channel 201 is connected to the throttle hole 104, and the second oil outlet channel 202 extends radially, with its outer end connected to the oil outlet hole 203. The oil outlet hole 203 consists of multiple small holes evenly distributed around the circumference of the second shaft body 2. Cooling oil is ultimately sprayed out from the oil outlet hole 203 to the outside of the shaft body, carrying away the heat from the shaft's central region. The working process of the motor cooling structure described in this embodiment is as follows: Oil cooling process: External cooling oil is continuously injected into the oil inlet channel 102 through the oil injection hole 101 at the end of the first shaft 1. The cooling oil is axially transported along the oil inlet channel 102 to the position of the throttle hole 104 and then divided into two paths: one path enters the cavity 205 through the oil inlet hole 103, forming the main heat dissipation branch of the rotor; the other path enters the first oil outlet channel 201 through the throttle hole 104 and the elastic valve plate 105, forming the shaft heat dissipation branch.

[0039] The cooling oil entering cavity 205, under the centrifugal force generated by the rotation of the shaft, adheres to the inner wall of cavity 205 and flows in a bidirectional spiral direction along the spiral guide groove 204 to both sides of cavity 205, fully contacting the shaft wall and absorbing the heat conducted by the rotor assembly from all directions, achieving uniform cooling of the entire rotor. The conical slope guides the oil to be evenly distributed to both ends, avoiding local overheating.

[0040] Cooling oil from the shaft branch is ejected from the oil outlet 203 through the second oil outlet channel 202, carrying away heat from the shaft center area. Under light load and low speed conditions, the rotor heat generation power is low, and the oil pressure inside the oil circuit is lower than the preset opening threshold. The elastic valve plate 105 relies on its own elasticity to tightly seal the throttling orifice 104, preventing a large amount of cooling oil from entering the oil outlet channel. Only a small amount of oil circulation is maintained, reducing cooling oil consumption and churning losses. Under heavy load and high speed conditions, the rotor loss heat generation increases significantly, and the oil pressure inside the oil circuit rises. The oil pressure continuously pushes the elastic valve plate 105 to undergo elastic deformation, causing the valve plate to detach from the throttling orifice 104. Cooling oil flows steadily into the oil outlet channel, greatly improving heat dissipation efficiency and matching the high load heat dissipation requirements.

[0041] Air-cooled heat dissipation process: The air-cooled heat dissipation component 8 rotates synchronously with the second shaft 2, generating negative pressure inside the sealing cover 901. Outside ambient air passes through the protective mesh 903 on the sealing component 9 to filter impurities. The clean airflow, driven by the fan pressure, is then sent into the air inlet of the W-shaped air duct 601 on the outer wall of the housing 6. The airflow follows the reciprocating bends of the W-shaped air duct 601, adhering to the outer wall of the housing 6 throughout, continuously carrying away the heat generated by the stator assembly 4. After heat exchange, the high-temperature hot air is discharged outwards along the other end of the W-shaped air duct 601 to the external environment of the motor, continuously carrying away the heat accumulated on the stator side.

[0042] The oil cooling system cools the core heat-generating components inside the motor, such as the rotor and bearings, while the air cooling system cools the heat-generating components on the outside of the motor, such as the stator. The two cooling systems operate independently and do not interfere with each other. They simultaneously remove heat loss from both the inside and outside of the motor, avoiding the shortcomings of insufficient rotor cooling by air cooling alone and insufficient heat exchange area of ​​stator by oil cooling alone. This significantly reduces the overall operating temperature rise of the motor and improves the continuous output capability and insulation life of high-power motors.

[0043] This embodiment also provides a motor cooling method that integrates shaft oil cooling and air cooling. Based on the above cooling structure, it specifically includes the following steps: S1. Cooling oil injection and distribution: Cooling oil is injected through the oil injection hole 101 on the first shaft 1. The cooling oil is axially transported to the position of the throttle hole 104 through the oil inlet channel 102. Part of the cooling oil enters the cavity 205 of the second shaft 2 through the oil inlet hole 103, and the other part of the cooling oil acts on the elastic valve plate 105 at the throttle hole 104. The elastic valve plate 105 adaptively adjusts the opening according to the real-time oil pressure in the oil circuit to control the flow rate of cooling oil entering the first oil outlet channel 201 and the second oil outlet channel 202.

[0044] S2. Rotary shaft oil cooling: The cooling oil entering the cavity 205 flows spirally to both ends along the spiral guide groove 204 on the inner wall of the cavity 205 under the action of the centrifugal force of the rotating shaft, extending the heat exchange path and breaking the thermal boundary layer, fully absorbing the heat conducted by the rotating shaft and rotor assembly 3; the cooling oil entering the first oil outlet channel 201 and the second oil outlet channel 202 is discharged to the outside of the shaft through the oil outlet hole 203, taking away the heat in the shaft core area and completing the oil cooling of the rotor side.

[0045] S3. Stator air cooling: The rotating shaft drives the air cooling component 8 to rotate synchronously, drawing in and pressurizing the outside air after it is filtered by the protective mesh 903. The pressurized air is sent into the W-shaped air duct 601 on the outer wall of the casing 6. During the flow of the air along the W-shaped corrugated channel, it undergoes forced convection heat exchange with the outer wall of the casing 6, carrying away the heat conducted by the stator component 4. The hot air after heat exchange is discharged to the outside from the other end of the air duct, completing the air cooling of the stator side.

[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A motor cooling structure integrating shaft oil cooling and air cooling, characterized in that: The device includes a shaft assembly, a rotor assembly, a stator assembly, a housing, an end cover assembly, a bearing assembly, an air-cooled heat dissipation assembly, and a sealing assembly. The rotor assembly is fixed to the outside of the shaft assembly, and the stator assembly is fixedly installed inside the housing and arranged around the rotor assembly, with a motor air gap reserved between them. The end cover assembly is sealed and fixed to both ends of the housing, and the bearing assembly is installed between the end cover assembly and the shaft assembly to support the rotation of the shaft assembly. The air-cooled heat dissipation assembly is installed at the end of the shaft assembly, and the sealing assembly covers the outside of the housing and the air-cooled heat dissipation assembly.

2. The motor cooling structure integrating shaft oil cooling and air cooling according to claim 1, characterized in that: The rotating shaft assembly includes a first shaft and a second shaft that are sealed together. Both shafts have hollow oil passages inside and are interconnected to form an oil-cooling circulation channel. The first shaft contains an oil injection hole, an oil inlet channel, an oil inlet port, a throttling orifice, and a flexible valve plate. The oil injection hole is located on the outer wall of the end of the first shaft opposite to the second shaft and communicates with the oil inlet channel. The oil inlet ports are radially distributed and connect the oil inlet channel to the interior of the second shaft. The throttling orifice is located at the end of the oil inlet channel. The flexible valve plate is mounted on the end of the throttling orifice facing the oil outlet side, used to regulate the oil flow according to the internal oil passage. The oil pressure adaptively completes the opening and closing to adjust the oil flow rate; the second shaft body has a cavity inside, and the inner wall of the cavity is surrounded by a spiral guide groove, which extends axially to both ends of the cavity. The second shaft body also has an oil outlet channel communicating with the throttling orifice and oil outlet holes distributed radially; the outer wall of the housing is provided with a W-shaped air duct along the axial direction. The W-shaped air duct is composed of a continuous W-shaped corrugated structure, and its two ends pass through the assembly surfaces at both ends of the housing; the oil cooling circulation channel and the air cooling heat dissipation assembly work together to perform zoned heat dissipation on the rotor side and the stator side respectively.

3. The motor cooling structure integrating shaft oil cooling and air cooling according to claim 2, characterized in that: The cavity gradually increases in diameter from the middle symmetrical position to both ends, forming a symmetrical conical slope; the spiral direction of the spiral guide groove is consistent with the working rotation direction of the shaft, and its groove depth and pitch gradually increase from the middle of the cavity to both ends, with the spiral helix angle set to 30° to 60°.

4. The motor cooling structure integrating shaft oil cooling and air cooling according to claim 3, characterized in that: The diameter of the throttling orifice is smaller than the diameter of the oil inlet channel; the elastic valve plate is a thin metal sheet with elasticity, one end of which is fixed to the inner wall of the oil inlet channel, and the other end freely covers the throttling orifice; when the oil pressure inside the oil circuit is higher than the preset threshold, the elastic valve plate undergoes elastic deformation to open, increasing the oil flow rate; when the oil pressure is lower than the preset threshold, the elastic valve plate resets and blocks the throttling orifice, reducing the oil flow rate.

5. The motor cooling structure integrating shaft oil cooling and air cooling according to claim 4, characterized in that: The oil outlet channel includes a first oil outlet channel and a second oil outlet channel. The outlet ends of the two channels are located at the ends of the second shaft body away from the first shaft body. The cooling oil is directly sprayed to the outside of the second shaft body through the oil outlet holes.

6. The motor cooling structure integrating shaft oil cooling and air cooling according to claim 5, characterized in that: The end cap assembly is disassembled and fixed to both ends of the housing through positioning holes, and sealing gaskets are installed at the joint gap between the two. The bearing assembly includes two sets of bearings, which are respectively embedded and fixed in the central mounting holes of the end cap assemblies at both ends. The inner ring of the bearing is interference-fitted with the first shaft and the second shaft respectively, and the outer ring of the bearing is interference-fitted with the end cap assembly, together bearing the radial load and axial load of the shaft assembly and the rotor assembly.

7. The motor cooling structure integrating shaft oil cooling and air cooling according to claim 6, characterized in that: The air-cooled heat dissipation component is a centrifugal fan, which is fixedly assembled on the end of the second shaft away from the first shaft by a keyway and a flat key, and rotates synchronously with the shaft; the sealing component forms an annular air cavity between itself and the housing, and the fan blade outlet faces the annular air cavity, which is used to radially throw air into the W-shaped air duct.

8. The motor cooling structure integrating shaft oil cooling and air cooling according to claim 7, characterized in that: The crests of the W-shaped air duct fit against the outer wall of the casing, and the troughs form an airflow channel between the troughs and the outer wall of the casing. The inner wall of the air duct is mirror-polished, and large rounded corners are provided at the corners to reduce wind resistance and balance the airflow of each parallel branch.

9. The motor cooling structure integrating shaft oil cooling and air cooling according to claim 8, characterized in that: The sealing assembly includes a sealing cover, a sealing cap, and a protective mesh; the sealing cover is installed along the boss of the housing for sealing, the sealing cap is detachably installed at the end of the sealing cover and its position corresponds to the air-cooled heat dissipation assembly, and the protective mesh is set at the air inlet of the sealing cap to filter dust and impurities in the outside air.

10. A motor cooling method integrating shaft oil cooling and air cooling, based on the motor cooling structure of claim 9, characterized in that, Includes the following steps: S1. Cooling oil injection and distribution steps: Cooling oil is injected through the oil injection hole on the first shaft. After being transported through the oil inlet channel, the cooling oil is divided into two paths. One path enters the cavity of the second shaft through the oil inlet hole, and the other path enters the oil outlet channel after passing through the throttle hole and adaptively adjusting the opening of the elastic valve plate. S2. Rotary shaft oil cooling heat dissipation steps: The cooling oil entering the cavity flows spirally towards both ends of the cavity along the spiral guide groove under the action of centrifugal force generated by the rotation of the shaft, and exchanges heat with the inner wall of the cavity to remove the heat of the rotor assembly and the shaft; the cooling oil entering the oil outlet channel is discharged through the oil outlet hole, removing the heat of the shaft core area. S3. Stator air-cooling heat dissipation steps: The rotating shaft drives the air-cooling heat dissipation components to rotate synchronously, drawing in external air and pressurizing it before sending it into the W-shaped air duct of the casing. The airflow flows along the W-shaped air duct and undergoes forced convection heat exchange with the outer wall of the casing. The hot air after heat exchange is discharged to the outside, completing the air-cooling cooling of the stator components.

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