High-speed motor stator end composite heat dissipation system and heat dissipation method

Abstract

The application discloses a high-speed motor stator end composite heat dissipation system and a heat dissipation method, wherein a liquid cooling water channel and a heat dissipation fin are arranged outside the casing of the high-speed motor, and a detachable air-strike turbulence component fixed on a rotor shaft is arranged between a stator end and an end cover; when the motor runs at high speed, the air-strike turbulence component rotates coaxially with the rotor, guides airflow to perform forced circulation in an annular cavity at the end, destroys a heat exchange boundary layer of the stator end, and improves the convective heat exchange efficiency between the end and the gas; heat of the stator end is transmitted to the inner wall of the casing through the disturbed airflow, and then is dissipated to the outside through the liquid cooling of the casing and the natural convection of the fin. The application utilizes the rotational kinetic energy of the rotor to drive air-strike to strengthen end heat exchange, does not need to introduce external airflow, has no additional driving components, is compact in structure, good in sealing performance, and balances heat dissipation efficiency and structural reliability.

Description

Technical Field

[0001] This invention belongs to the field of high-speed motor thermal management technology, specifically relating to a composite heat dissipation system and method for the stator end of a high-speed motor. Background Technology

[0002] High-speed motors are rapidly developing towards higher power density, miniaturization, and higher speeds, resulting in increasingly compact internal spaces and significantly increased loss density. Because the stator winding ends are far from the main cooling channels, the heat transfer path is long, and air is a poor thermal conductor. Therefore, localized hot spots easily form at the stator winding ends, becoming a key factor restricting motor reliability and lifespan.

[0003] The existing main heat dissipation solution for high-speed motors involves creating spiral or axial closed liquid cooling channels inside or on the outer surface of the motor housing. During motor operation, coolant (such as a mixture of water, oil, or ethylene glycol) is introduced. As the coolant flows through the liquid cooling channels, it carries away heat from the stator core and the housing through the metal walls, achieving forced liquid cooling. Simultaneously, multiple thin metal fins are added to the outer surface of the housing to increase the contact area with the outside air, utilizing natural air convection (i.e., the circulation of rising hot air and replenishing it with cool air) to help dissipate residual heat from the housing surface. While this solution effectively controls the temperature rise of the stator core and the housing itself, the stator winding ends are not located on this cooling path. Heat must travel a relatively long path from the stator winding ends to the housing cooling surface, and the low thermal conductivity of air causes heat to easily accumulate near the stator winding end surfaces, creating a significant temperature gradient. Furthermore, the airflow within the annular cavity formed between the stator winding end and the motor end cover is predominantly laminar, with fluid flowing in stratified layers. There is no macroscopic radial mixing between the layers, only molecular-level thermal diffusion. Within this annular cavity, the air flows slowly tangentially or axially in a laminar state, without generating vortices or scouring effects perpendicular to the end surface, resulting in a low convective heat transfer coefficient, only approximately [value missing]. The direct consequence of a low convective heat transfer coefficient is that heat is difficult to transfer effectively to the outside, the temperature at the end of the stator winding remains high, which accelerates insulation aging, reduces motor efficiency, and in severe cases can even lead to thermal failure.

[0004] To address the aforementioned issues, current improvement solutions include oil spraying / immersion cooling, adding an external fan, and internal potting with thermally conductive materials. Oil spraying / immersion cooling achieves efficient heat exchange by directly spraying insulating oil or coolant onto the stator winding ends, but it requires auxiliary systems such as oil pumps, filters, and oil-gas separators, significantly increasing system complexity and cost. Furthermore, high-speed rotation introduces additional oil churning losses, and research indicates that immersion cooling may lead to significant rotor friction losses, further reducing motor efficiency. External fans or independent air-cooling circuits enhance stator end heat exchange through forced convection. While this directly and effectively dissipates heat from the stator ends, the additional fans require independent power supplies, increasing motor size and energy consumption, which conflicts with the design goals of high-speed motors that prioritize high efficiency and high power density.

[0005] The end-capsulation thermal conductive material solution, which fills the stator winding ends with highly thermally conductive epoxy resin or silicone, aims to enhance the solid-state thermal conduction path from the heat source to the housing. However, the potting material only shortens the conduction distance and does not truly solve the bottleneck in heat transport between the stator winding ends and the housing before it finally enters the liquid cooling circuit. Ultimately, heat dissipation still relies on liquid cooling of the housing. In addition, the potting material significantly increases the weight of the motor, which is not conducive to lightweight design and also brings trouble to later maintenance and modification. Once cured, it is almost impossible to remove.

[0006] Currently, some high-speed motor research has attempted to disrupt the laminar boundary layer by adding a turbulence device at the rotor end, relying on rotation to agitate the air in the end cavity. However, these solutions all involve placing the turbulence device at the rotor end, requiring related supporting facilities or partial modifications to the motor, and the airflow direction is mainly tangential. For example, patent CN101557143B discloses a liquid-cooled motor and a method for cooling such a motor. This solution arranges a coolant coil in the winding end space, and simultaneously sets a fan impeller at the rotor end to drive internal air circulation. The air flows through the cooling coil to cool down and then washes the winding end. This solution also achieves counter-current circulation between the two end cavities through an axial air pipe inside the rotor, but it requires opening ventilation holes in the winding neck and machining a special air passage inside the rotor, resulting in high overall structural complexity and the liquid cooling components penetrating deep into the motor's internal cavity. Patent CN208078821U discloses a synchronous reluctance motor with an end winding heat dissipation structure. Its core method is to integrate centrifugal fan blades on the outer end face of the rotor pressure plate. By rotating the fan blades with the rotor, the air flow velocity in the end cavity is increased to enhance air convection heat dissipation. This solution only modifies the rotor pressure plate and does not have a matching liquid cooling system. It is a basic air-cooling enhancement solution. It has a simple structure and low cost, but the heat dissipation improvement is limited and it is difficult to effectively dissipate the heat of the end annular cavity. Summary of the Invention

[0007] To address the issues of high system complexity, cost, and poor heat dissipation efficiency in existing stator end cooling technologies, this invention provides a composite heat dissipation system and method for the stator end of a high-speed motor. Without altering the main motor structure, adding extra power components, or significantly increasing the motor weight, this invention utilizes existing liquid cooling channels and heat dissipation fins on the casing for convective cooling. A wind-induced turbulence component is detachably installed at the rotor shaft end, forming a composite heat dissipation structure with forced convection at the stator end. These two components synergistically improve the convective heat transfer efficiency at the stator end, effectively suppressing hot spots and enhancing the overall cooling performance and operational reliability of the motor. This provides reliable thermal management support for the development of high-power-density, high-speed motors.

[0008] To achieve the above objectives, the technical solution provided by this invention is:

[0009] A composite heat dissipation system for the stator end of a high-speed motor includes a housing, a stator winding and a rotor assembly disposed inside the housing, and end caps sealed and fixedly connected to both ends of the housing; the inner wall of the housing is provided with liquid cooling channels, and the outer wall of the housing is provided with heat dissipation fins; it also includes an air blasting and turbulence assemblies, which are coaxially and detachably mounted on the rotor shaft of the rotor assembly and located in the annular cavity formed by the end of the stator winding and the end caps;

[0010] The wind-spiking spoiler assembly includes a wind-spiking spoiler disk and spoiler ribs. The spoiler ribs are protruding structures on the disk surface of the wind-spiking spoiler disk facing the stator winding side.

[0011] Multiple fins are provided, and the multiple fins are evenly distributed around the circumference of the wind-piercing spoiler disk. Each fin extends outward along the radial direction of the wind-piercing spoiler disk from a position close to the center of the wind-piercing spoiler disk.

[0012] The airflow disturbance component is configured to: guide the airflow in the air gap between the rotor and the stator winding into axial turbulent airflow along the rotor axis toward the end of the stator winding when rotating synchronously with the rotor, and at the same time apply shear disturbance to the airflow in the end annular cavity, so that the airflow in the end annular cavity is transformed from laminar flow to turbulent flow.

[0013] Furthermore, the spoiler ribs are teardrop-shaped ribs with a top view on the wind-sharp spoiler disk. The teardrop-shaped ribs are distributed in a ring array around the center of the wind-sharp spoiler disk. Each teardrop-shaped rib has a pointed end and a rounded end opposite to it. The pointed end points to the center of the wind-sharp spoiler disk, and the rounded end is radially away from the center of the wind-sharp spoiler disk.

[0014] Furthermore, the spoiler ribs are ribs with an arc-shaped profile when viewed from above on the wind-sharp spoiler disk. The arc-shaped ribs extend radially outward from the center of the wind-sharp spoiler disk, and all the arcs have the same bending direction. According to the direction of the concave surface, they can be divided into forward-curved arcs in the same direction as the rotation direction and backward-curved arcs in the opposite direction.

[0015] Furthermore, the spoiler rib is a rib with an airfoil-shaped profile when viewed from above on the wind-spiking spoiler disk. The airfoil rib includes a leading edge and a trailing edge. The leading edge is arc-shaped and the trailing edge is pointed. The leading edge faces the center of the wind-spiking spoiler disk and is directed towards the air gap flow direction, while the trailing edge is radially away from the center of the wind-spiking spoiler disk.

[0016] Furthermore, the height of the bulge of the spoiler rib along its axial direction from the surface of the wind-sharpening spoiler is 2-4 mm; the thickness of the wind-sharpening spoiler is 2 mm.

[0017] Furthermore, the wind-piercing spoiler and the spoiler ribs are integrally formed; the wind-piercing spoiler is detachably and fixedly connected to the rotor shaft by means of center interference fit, key connection or threaded locking.

[0018] Furthermore, a vibration damping bushing is provided between the inner wall of the center hole of the wind-piercing spoiler and the outer wall of the rotor shaft.

[0019] Furthermore, there are safety gaps between the wind-spraying spoiler and the end cover, and between the spoiler ribs and the stator winding ends. The design range of the safety gaps is 2mm to 4mm. The outer diameter of the wind-spraying spoiler is smaller than the inner diameter of the housing.

[0020] This invention also provides a high-speed motor heat dissipation method, which employs the aforementioned composite heat dissipation system at the stator end of the high-speed motor; the high-speed motor heat dissipation method includes the following steps:

[0021] End heat accumulation and airflow diversion steps:

[0022] When the high-speed motor is started, Joule heat is generated in the stator windings and accumulates at the ends of the stator windings, forming local hot spots; the high-speed rotation of the rotor drives the wind-piercing turbulence components coaxially fixed on its rotor shaft to rotate synchronously.

[0023] As the rotor shaft rotates, the turbulence ribs of the wind-piercing turbulence assembly guide the airflow in the air gap between the rotor and the stator into axial turbulence airflow flowing along the rotor axis toward the end of the stator winding. At the same time, it applies shear disturbance to the airflow in the end annular cavity, causing the airflow in the end annular cavity to change from laminar flow to turbulent flow.

[0024] Internal airflow heat exchange and heat transfer steps:

[0025] Axial turbulent airflow impacts the end surface of the stator winding, transforming the laminar thermal boundary layer on the end surface of the stator winding into a turbulent boundary layer, and forming a circulating three-dimensional vortex in the end annular cavity; the three-dimensional vortex sweeps across the end surface of the stator winding at multiple angles, carrying away the heat accumulated at the end of the stator winding through convection heat transfer, and transferring the heat to the inner wall of the casing.

[0026] Composite heat dissipation synergy and thermal balance maintenance process:

[0027] The heat transferred to the inner wall of the casing is dissipated outward in two ways: one is carried out by the coolant in the liquid cooling channel through forced convection heat exchange, and the other is dissipated to the external environment through the heat dissipation fins through natural convection.

[0028] Furthermore, it also includes a coolant introduction step:

[0029] Before or during the start-up of the rotor, coolant is introduced through the inlet of the liquid cooling channel. After the coolant absorbs heat from the inner wall of the casing, it is discharged from the outlet of the liquid cooling channel.

[0030] The advantages of this invention are:

[0031] 1. To reliably dissipate heat accumulated at the stator winding ends in a motor, this invention adds a coaxial and detachably mounted airflow turbulence assembly to the rotor shaft, based on the traditional liquid cooling channels and heat dissipation fins on the outer wall of the casing. This assembly includes an airflow turbulence disk and turbulence ribs, with the ribs being protruding structures arranged radially along the disk. This invention utilizes the rotation of the rotor shaft itself to drive the airflow turbulence assembly to rotate synchronously. The ribs, on the one hand, guide the airflow in the air gap axially towards the stator winding ends, forming axial turbulent airflow; on the other hand, they apply shear disturbance to the airflow within the annular cavity at the ends, transforming the originally laminar airflow into turbulent flow. When the turbulent airflow impacts the end surface of the stator winding, it further disrupts the laminar boundary layer on the wall and transforms it into a turbulent boundary layer. This forms a three-dimensional vortex with the turbulence in the annular cavity at the end, sweeping the end of the stator winding at multiple angles. This enhances the convective heat transfer coefficient of the end surface of the stator winding and removes the heat accumulated at the end in a timely manner, fundamentally solving the problem of local overheating caused by the stator winding end being far from the main cooling path.

[0032] 2. The airflow disturbance of the present invention is entirely provided by the kinetic energy of the rotor rotation. As the motor speed increases, the speed of the wind-piercing turbulence disk increases synchronously, and the shearing effect and flow-guiding intensity of the turbulence ribs are enhanced accordingly, and the heat exchange capacity is improved synchronously. No additional power source is required, and the system complexity and operating energy consumption are not increased. This is consistent with the design direction of high-speed motors that pursue high efficiency and high power density.

[0033] 3. This invention uses air as the heat exchange medium, without increasing the weight of the motor body or changing the original assembly structure at the stator end. It only adds a positioning step and locking structure to the rotor shaft, and coaxially installs the wind blasting component at the rotor shaft end, achieving non-destructive installation. No destructive disassembly is required during maintenance, which increases the flexibility of maintenance and modification and avoids the weight increase and maintenance difficulties caused by traditional potting materials.

[0034] 4. In this invention, the heat from the stator winding ends is transferred to the inner wall of the housing via convection heat transfer. One path forcibly removes the heat through the liquid cooling channel, while the other path allows it to dissipate naturally through the heat dissipation fins on the motor housing. The two heat dissipation paths work together, and even if there are short-term fluctuations in the liquid cooling system, the natural convection of the heat dissipation fins can still handle part of the heat dissipation. The thermal stability and operating condition adaptability of the motor system are superior to a single heat dissipation scheme that relies entirely on the liquid cooling channel or entirely on the natural heat dissipation of the fins. Attached Figure Description

[0035] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0036] Figure 1 This is a three-dimensional half-sectional schematic diagram of the composite heat dissipation system at the stator end of the high-speed motor of the present invention;

[0037] Figure 2 This is a cross-sectional view of the composite heat dissipation system at the stator end of the high-speed motor of the present invention along the motor axis;

[0038] Figure 3 This is a schematic diagram of the structure of the wind-blown turbulence component in this invention;

[0039] Figure 4 This is a schematic diagram of the assembly of the wind-piercing turbulence component and the rotor component in this invention, and the direction of the wind-piercing turbulence effect.

[0040] Figure 5 yes Figure 2 A partially enlarged schematic diagram showing the airflow direction at the stator end;

[0041] Figure 6 These are schematic diagrams illustrating the structures of different styles of wind-piercing spoiler components provided by the present invention; wherein, Figure 6 (a) is teardrop-shaped, (b) is arc-shaped, and (c) is wing-shaped;

[0042] Figure 7 This is a stator temperature cloud map of the high-speed motor operating at 10,000 rpm in an embodiment of the present invention;

[0043] Figure 8 This is a flow field distribution diagram of the end annular cavity when the high-speed motor operates at 10,000 rpm in an embodiment of the present invention;

[0044] Figure 9 This is a stator temperature cloud map of the high-speed motor operating at 50,000 rpm in an embodiment of the present invention;

[0045] Figure 10 This is a flow field distribution diagram of the end annular cavity when the high-speed motor operates at a speed of 50,000 rpm in an embodiment of the present invention.

[0046] Reference numerals: 1-Casing, 2-Liquid cooling channel, 3-Liquid cooling channel inlet, 4-Liquid cooling channel outlet, 5-Heat dissipation fins, 6-Stator, 7-Stator winding end, 8-Rotor, 9-Rotor shaft, 10-End cover, 11-Wind blasting assembly, 12-Wind blasting disc, 13-Blast ribs, 14-End annular cavity. Detailed Implementation

[0047] The embodiments of the present invention are described in detail below. These embodiments are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0048] Reference Figure 1 This invention provides a composite heat dissipation system for the stator end of a high-speed motor, including a motor body assembly and a wind-blown turbulence assembly. The motor body assembly consists of a housing 1, a stator 6, a rotor 8, a rotor shaft 9, and end covers 10. A liquid cooling channel 3 is provided on the inner wall of the housing, its position corresponding radially to or simultaneously covering the end area of ​​the stator core, for introducing coolant to remove heat conducted by the housing and stator core. The liquid cooling channel 2 has a coolant inlet 3 and a coolant outlet 4. Heat dissipation fins 5 are provided on the outer wall of the housing, evenly distributed circumferentially and extending axially, exposed to the external ambient air, for assisting natural convection heat dissipation. The liquid cooling channel 3 and heat dissipation fins 5 are existing devices in conventional high-speed motors. The stator 6 is fixed inside the housing, the rotor shaft 9 is located inside the stator, and the rotor 8 is sleeved on the rotor shaft 9. Two end covers 10 are respectively sealed and fixedly connected to both ends of the housing, forming a closed internal cavity of the motor. No airflow passage is provided on the end cover 10, and the internal cavity of the motor is sealed and isolated from the external environment, which can effectively prevent external dust, water vapor and other impurities from entering.

[0049] Reference Figure 2 and Figure 3 The wind-piercing spoiler assembly 11 is a core component added to this invention. The wind-piercing spoiler assembly 11 includes a wind-piercing spoiler disk 12 and spoiler ribs 13, both integrally molded. The entire assembly is made of lightweight metal or non-metal materials, preferably aluminum-magnesium alloy, carbon fiber reinforced plastic, or polyetheretherketone (PEEK). This design reduces the weight of the wind-piercing spoiler assembly while ensuring structural strength and thermal conductivity, meeting the lightweight design requirements of high-speed motors. The overall weight of the wind-piercing spoiler assembly designed in this invention is approximately 0.015 kg. The wind-piercing spoiler assembly 11 is detachably and coaxially fixedly mounted on the rotor shaft 9, located within the annular cavity 14 between the stator winding end 7 and the end cover 10, and rotates synchronously with the rotor shaft 9. This detachable design makes this invention suitable for lightweight retrofitting of existing high-speed motors. The wind-piercing spoiler assembly 11 can be added to the end of the rotor shaft 9 simply by opening the end cover 10, without requiring modifications to core components such as the stator 6 and rotor 8. The outer diameter of the wind-piercing spoiler 12 is smaller than the inner diameter of the housing to avoid dimensional interference with the inner diameter of the housing.

[0050] The turbulence ribs 13 are disposed on the side of the wind-piercing turbulence disk 12 facing the stator winding end 7, and are evenly distributed circumferentially. The axial protrusion height of the turbulence ribs from the disk surface of the wind-piercing turbulence disk is 2-4 mm. The lower limit of the rib protrusion height is set at 2 mm to ensure that it completely penetrates the laminar thermal boundary layer on the stator end surface during rotation, realizing effective turbulent conversion and axial airflow guidance, and ensuring heat transfer enhancement effect. The upper limit is set at 4 mm to avoid the wind resistance loss from increasing sharply with the windward area at high speed, while reserving sufficient safety clearance to avoid the risk of mechanical interference, and controlling the centrifugal stress at the root of the rib to ensure structural strength. In this embodiment, there are 8 turbulence ribs 13, and the protrusion height is 2 mm.

[0051] In this embodiment, the thickness of the wind-piercing spoiler needs to be determined by comprehensively considering the space within the annular cavity and the mechanical strength requirements. Since excessively high rib height leads to high wind friction loss, while excessively low height results in insignificant turbulence, this embodiment designs the wind-piercing spoiler to have a thickness of 2mm. This thickness design satisfies the structural rigidity and operational stability requirements at the highest speed, reliably supports the ribs and transmits torque, controls the rotational inertia and end-face wind friction loss of rotating components, fits the compact axial space of the end annular cavity described in this embodiment, and combines good manufacturability with lightweighting. To ensure no contact risk and mechanical interference between the wind-piercing spoiler assembly and the stator winding under high vibration and high speed operating environments, guaranteeing the safe operation of the motor system, safety gaps are provided between the wind-piercing spoiler 12 and the end cover 10, and between the spoiler rib 13 and the stator winding end 7. The design range of these safety gaps is 2mm to 4mm. In this embodiment, the safety gap between the wind-spraying spoiler 12 and the end cover 10 is 2mm, and the safety gap between the spoiler rib 13 and the stator winding end 7 is 4mm.

[0052] Reference Figures 2-4 An end annular cavity 14 is formed between the stator winding end and the end cover 10 (e.g., Figure 2(As shown in the dashed area) The wind-piercing spoiler assembly 11 is located within this cavity, specifically using a combination of center interference fit and locking nut, and is coaxially fixed to the side of the rotor shaft 9 near the stator winding end 7. This arrangement ensures that the wind-piercing spoiler assembly 11 and the stator winding end 7 maintain an axial relative relationship, with the spoiler ribs 13 facing the surface of the stator winding end 7, ensuring that the airflow generated during rotation directly acts on the surface of the stator winding end. The rotor shaft 9 also has a positioning step (not shown in the figure due to view obstruction). This positioning step, in conjunction with the locking nut, achieves axial limitation of the wind-piercing spoiler disk, ensuring that the wind-piercing spoiler assembly 11 and the rotor shaft 9 rotate synchronously without relative slippage. In addition to the above interference fit method, the fixation between the wind-piercing spoiler assembly 11 and the rotor shaft 9 can also be achieved by key connection or threaded locking. In applications requiring higher vibration reduction, a vibration damping bushing can be added between the wind-piercing spoiler disk 12 and the rotor shaft 9 to absorb the vibration energy generated by high-speed rotation and reduce the stress between the spoiler assembly and the rotor shaft.

[0053] Specifically, multiple turbulence ribs 13 are evenly distributed around the circumference of the wind-piercing turbulence disk 12 on one side of the disk surface. Each turbulence rib 13 extends radially outward from a position near the center of the wind-piercing turbulence disk. The turbulence ribs are raised structures arranged radially along the wind-piercing turbulence disk. During the high-speed synchronous rotation of the wind-piercing turbulence assembly with the rotor, the turbulence ribs 13 guide the airflow in the air gap between the rotor 8 and the stator through their guide surfaces, transforming it into axial turbulent airflow flowing axially towards the end of the stator winding. Simultaneously, they apply shear disturbance to the airflow in the end annular cavity 14, causing the airflow in the end annular cavity to change from laminar to turbulent, and the laminar flow on the end surface of the stator winding to turbulent flow. The axial turbulent airflow also impacts the surface of the stator winding end 7, transforming the laminar thermal boundary layer on the stator winding end surface into a turbulent boundary layer, and forming a circulating three-dimensional vortex in the end annular cavity, such as... Figure 5 As shown.

[0054] The shape of the baffle fins 13 can be changed according to actual operating conditions to meet the heat dissipation requirements of specific operating conditions. For example... Figure 6As shown, the spoiler ribs can be arranged in two forms: radial straight ribs or inclined ribs. The inclination angle of the inclined ribs is based on the radial direction of the wind-piercing spoiler disk, that is, the straight line in the radial direction from the center of the spoiler disk to the outer edge is the reference line. The angle between the center line of the rib length direction and the reference line in the plane of the spoiler disk end face is the inclination angle. The preferred range of this inclination angle is 15° to 35°. This range is constrained by the flow guiding effect, loss control and structural reliability, and has been verified by a large number of tests. Experiments show that if the tilt angle is less than 15°, the flow characteristics of the fins on the airflow are basically the same as those of the radial straight fins. The axial pumping and directional guidance effects on the airflow are weak, making it difficult to effectively enhance the axial delivery of the air gap airflow to the end of the stator winding. Therefore, the heat transfer benefits brought by the tilt design are very limited. When the tilt angle is greater than 35°, the circumferential windward area of ​​the fins increases significantly. The wind friction loss under high-speed rotation conditions will increase rapidly with the increase of the tilt angle, and the increase in additional power consumption will exceed the efficiency gains brought by the improvement in heat dissipation. At the same time, an excessively large tilt angle will reduce the normal shear strength of the fins on the airflow, which is not conducive to the peeling of the laminar thermal boundary layer on the winding surface. Moreover, the centrifugal bending stress borne by the root of the fins will increase significantly, reducing the structural reliability under high-speed operation.

[0055] Different profiles of the spoiler ribs affect the direction and shear strength of airflow. Radial straight ribs primarily generate tangential shear disturbances, while inclined ribs can simultaneously generate shear disturbances and axial flow. Specifically, the top-view profile of the spoiler ribs 13 on the wind-piercing spoiler disk 12 is preferably teardrop-shaped, arc-shaped, or airfoil-shaped. Different rib shapes affect the direction and shear strength of airflow. Radial straight ribs primarily generate tangential shear disturbances, while inclined ribs can simultaneously generate shear disturbances and axial flow. Specifically, teardrop-shaped ribs are arranged in a ring array around the center of the wind-piercing spoiler disk. Each teardrop-shaped rib has a pointed tip and an opposite blunt end. The pointed tip points towards the center of the wind-piercing spoiler disk, while the blunt end radially moves away from the center. This design results in low drag, with its primary function being tangential turbulence, effectively controlling wind friction loss under high-speed operating conditions. The ribs, with an arc-shaped profile when viewed from above, extend radially outward from the center of the spoiler disk. All arc-shaped ribs bend in the same direction, and based on the orientation of their concave surfaces, they can be divided into forward-curved arcs (in the same direction as rotation) and backward-curved arcs (in the opposite direction). The forward-curved arcs have stronger axial airflow guidance capabilities, while the backward-curved arcs have lower operating losses, adaptable to different operating conditions. The ribs, with an airfoil-shaped profile when viewed from above, employ an aerodynamic profile of a rounded leading edge and a pointed trailing edge. The leading edge faces the center of the spoiler disk and the direction of the incoming airflow in the air gap, while the trailing edge radially moves away from the center of the spoiler disk. This arrangement reduces airflow separation losses and provides superior overall performance in terms of both airflow guidance and turbulence under the same losses.

[0056] The parameters described above are optimal parameters based on this embodiment and should not be construed as limiting the scope of the invention. In practical engineering applications, the above parameters can also be adaptively adjusted according to the motor power rating, speed range, and end annular cavity size, etc.

[0057] The following describes in detail the heat dissipation method of the composite heat dissipation system at the stator end of a high-speed motor designed based on the present invention, including the following steps:

[0058] (1) Steps for heat accumulation and airflow at the end:

[0059] After the high-speed motor starts running, current flows through the stator winding, generating Joule heat. Because the stator winding end 7 is far from the liquid cooling surface of the housing 1, the heat transfer path is long, and the air in the end annular cavity 14 has low thermal conductivity, the air on the end surface is rapidly heated, and heat accumulates near the surface of the stator winding end 7, forming local hot spots and a large temperature gradient.

[0060] The high-speed rotation of rotor 8 drives the wind-blown aerodynamic assembly 11 to rotate synchronously, and in turn drives the air gap airflow in the closed cavity inside the motor. This air gap airflow includes the air gap airflow between the stator and rotor, and the airflow between the stator end air gap and the rotor. Figure 4 As shown, the turbulence fin 13 generates two airflow-driven effects during rotation: First, the side of the turbulence fin 13 guides the airflow in the air gap, drawing the air in the air gap between the rotor 8 and the stator 6 axially out along the rotor shaft 9, forming an axial turbulent airflow from the air gap to the stator winding end 7. Second, the circumferential motion of the turbulence fin 13 applies shear disturbance to the airflow in the end annular cavity 14, causing the airflow in the end annular cavity to change from laminar to turbulent, thereby increasing the convective heat transfer coefficient between the stator winding end surface and the gas inside the end annular cavity 14.

[0061] (2) Internal airflow heat exchange and heat transfer steps:

[0062] Under the continuous rotational agitation of the turbulence fins 13, the axial turbulent airflow acts on the end surface of the stator winding, causing the laminar thermal boundary layer on the end surface of the stator winding to transform into a turbulent boundary layer. The turbulent airflow within the end annular cavity 14 further evolves into a circulating three-dimensional vortex system. Figure 6 As shown, the three-dimensional vortex system rotates in the circumferential direction and reciprocates between the surface of the stator winding end 7 and the inner wall of the housing 1 in the axial direction, sweeping the surface of the stator winding end 7 at multiple angles. The convective heat transfer coefficient between the wall and the fluid is further improved. The heat accumulated at the end of the stator winding is removed through convective heat transfer, avoiding the accumulation of heat in the local air layer at the end of the stator winding.

[0063] The heat accumulated at the end 7 of the stator winding is transferred to the airflow in the end annular cavity 14 through convection heat transfer. The heated airflow moves to the inner wall of the housing 1 and then transfers the heat to the inner wall of the housing.

[0064] (3) Steps for combined heat dissipation and thermal balance maintenance:

[0065] The heat transferred to the inner wall of the housing 1 is dissipated outward through the two existing heat dissipation channels of the high-speed motor. One channel is conducted through the side wall of the housing 1 to the liquid cooling channel 2, where it is carried away by the coolant through forced convection heat exchange. Specifically, before starting the rotor rotation or during rotation, coolant is introduced into the liquid cooling channel inlet 3. After absorbing heat from the inner wall of the housing, the coolant flows through the liquid cooling channel 2 and is discharged from the liquid cooling channel outlet 4, thus realizing the outward transfer and dissipation of heat conducted by the housing and stator core. The coolant is preferably 4050 aviation lubricating oil, and the coolant flow rate is preferably 3-6 m / s. In this embodiment, the coolant flow rate is set to 4.3 m / s.

[0066] Another route is through the outer wall of the casing 1 to the heat dissipation fins 5, and the heat dissipation fins 5 dissipate the heat from the surface of the casing 1 to the external environment through natural convection.

[0067] This invention enhances the front-end heat transfer link between the stator winding end heat source, internal gas, and the inner wall of the housing by adding an airflow turbulence component 11. This allows for efficient heat transfer from the stator winding end to the inner wall of the housing 1, where existing liquid cooling channels and heat dissipation fins are used for final heat dissipation, forming a composite heat dissipation system. This system can quickly balance the internal heat of the motor, keeping the temperature of the stator winding end 7 within a safe range and ensuring long-term stable operation of the motor. The composite heat dissipation system of this invention relies entirely on the rotation of the motor itself to drive the airflow turbulence component 11 to maintain airflow turbulence circulation, achieving stable turbulence heat dissipation under all operating conditions, whether at low or high speeds, without relying on any external power source.

[0068] The turbulence intensity of the wind-piercing turbulence component 11 is positively correlated with the rotor speed 8. Under low-speed conditions, the turbulence intensity is moderate; under high-speed, high-load conditions, as the heat generated at the stator winding ends increases dramatically, the rotor speed 8 increases, leading to an increase in internal airflow velocity. Consequently, the rotational speed of the wind-piercing turbulence component also increases, and the turbulence intensity is simultaneously enhanced, forming an adaptive heat dissipation capability that matches the thermal load. Furthermore, since the end cover 10 does not have inlet or outlet air passages, the internal cavity of the motor remains sealed and isolated from the external environment. The wind-piercing turbulence effect is entirely achieved within the closed cavity, avoiding the risk of external dust, moisture, corrosive gases, and other contaminants entering the motor.

[0069] Although the wind-piercing turbulence assembly 11 generates a small amount of additional power loss due to the high-speed rotation of the rotor shaft 9, actual verification shows that under typical motor operating conditions (speed range 10,000–50,000 r / min), the additional power loss introduced by adding the wind-piercing turbulence assembly designed in this invention is approximately in the hundreds of watts range, while the temperature drop at the stator winding end can reach 20–40°C, keeping the stator winding end temperature within the safe threshold of 180°C. This allows the motor to output higher power at the same temperature boundary, with a measured increase in motor power density of over 15%. It also reduces the thermal aging rate of the stator winding insulation, improving motor reliability and lifespan. Therefore, the overall effect of adding the wind-piercing turbulence assembly far outweighs the additional losses it brings.

[0070] To verify the actual heat dissipation effect of the wind-piercing turbulence component of this invention, this embodiment establishes a simulation model of the overall heat transfer of a certain type of high-power-density, high-speed motor. During operation, 4050 aviation lubricating oil with a flow rate of 4.3 m / s is introduced into the cooling channels on the inner wall of the motor casing to remove heat conducted from the casing and stator core; simultaneously, heat dissipation fins are distributed on the outer surface of the casing to assist in natural convection cooling. The aforementioned cooling channels and heat dissipation fins remain unchanged in the comparative simulation test; the only change is whether or not the wind-piercing turbulence component of this invention is installed.

[0071] In this example, the wind-spraying spoiler and the spoiler ribs are integrally formed into a disc-shaped structure, made of aluminum-magnesium alloy, with a weight of 0.015kg. The side of the spoiler ribs facing the stator winding end has 8 spoiler ribs evenly distributed circumferentially, with a protrusion height of 2mm. The safety clearance between the wind-spraying spoiler and the end cover is 2mm, and the safety clearance between the spoiler ribs and the stator winding end is 4mm. There is no mechanical interference between the components.

[0072] The simulation conditions were set at typical operating speeds of 10,000 rpm and 50,000 rpm. Under the same simulation model, the temperature field of the top and the flow field of the end annular cavity were compared between the side with the wind-blowering turbulence component (referred to as the wind-blowering side, i.e., the left side of the figure) and the side without the wind-blowering turbulence component (i.e., the right side of the figure). The results are as follows. Figures 7-10 As shown. Among them, Figure 7 and Figure 8 The stator temperature distribution and the flow field distribution within the annular cavity formed between the stator end and the end cover are shown respectively under an operating speed of 10000 rpm. Figure 7 It can be seen that the temperature on the side with the ventilator is approximately 118℃, while the highest temperature on the side without the ventilator reaches 138℃; from Figure 8 It can be seen that the turbulence on the side with the whistles is significant, while the airflow on the side without the whistles is basically stagnant. Figure 9 and Figure 10The stator temperature distribution and the flow field distribution within the annular cavity formed between the stator end and the end cover are shown respectively under an operating speed of 50,000 rpm. Figure 9 It can be seen that the temperature on the side with the air vents is approximately 103℃, while the highest temperature on the side without air vents is 138℃. From... Figure 8 It can be seen that the turbulence on the side with the whistles is significant, while the airflow on the side without the whistles is basically stagnant.

[0073] Based on the above data, it can be seen that the present invention effectively disrupts the thermal boundary layer within the annular cavity at the end by generating periodic disturbances as the rotor rotates through the wind-piercing turbulence component. This improves the convective heat transfer coefficient and allows the heat accumulated at the stator winding end to dissipate rapidly. Furthermore, the heat dissipation performance of the wind-piercing turbulence component increases synchronously with the increase of motor speed.

[0074] This invention retains the existing liquid cooling channel 2 and heat dissipation fins 5 of the high-speed motor, and only adds a wind-driven aerodynamic component 11 to the end of the rotor shaft 9. It requires no modification to core components such as the stator 6 and rotor 8, nor the addition of external fans, oil pumps, or other auxiliary power components, resulting in a simple structure and light weight. For existing motors already in operation, installation and modification can be completed simply by opening the end cover 10, resulting in a short cycle and low cost. The detachable design facilitates maintenance, and during inspection, the aerodynamic discs with different fin shapes can be disassembled for cleaning or replacement to adapt to different operating conditions.

[0075] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the scope of the technology disclosed in the present invention, and such modifications or substitutions should all be covered within the scope of protection of the present invention.

Claims

1. A composite heat dissipation system for the stator ends of a high-speed motor, comprising a housing, a stator winding and a rotor assembly disposed inside the housing, and end caps sealed and fixedly connected to both ends of the housing; the inner wall of the housing is provided with liquid cooling channels, and the outer wall of the housing is provided with heat dissipation fins; characterized in that, It also includes a wind-piercing turbulence assembly, which is coaxially and detachably mounted on the rotor shaft of the rotor assembly and located in the end annular cavity formed by the stator winding end and the end cover; The wind-piercing spoiler assembly includes a wind-piercing spoiler disk and spoiler ribs, wherein the spoiler ribs are protrusions on the disk surface of the wind-piercing spoiler disk facing the stator winding side. The deflector ribs are provided in multiple ways, and the multiple deflector ribs are evenly distributed around the circumference of the wind-piercing deflector disk, and each deflector rib extends radially outward from a position close to the center of the wind-piercing deflector disk. The wind-induced turbulence component is configured to: guide the airflow in the air gap between the rotor and the stator winding into an axial turbulent airflow flowing along the rotor axis toward the end of the stator winding when rotating synchronously with the rotor, and at the same time apply shear disturbance to the airflow in the end annular cavity, so that the airflow in the end annular cavity is transformed from laminar flow to turbulent flow.

2. The composite heat dissipation system at the stator end of the high-speed motor according to claim 1, characterized in that, The spoiler ribs are teardrop-shaped ribs with a top view on the wind-spiking spoiler disk. The teardrop-shaped ribs are arranged in a ring array around the center of the wind-spiking spoiler disk. Each teardrop-shaped rib has a pointed end and a rounded end opposite to it. The pointed end points to the center of the wind-spiking spoiler disk, and the rounded end is radially away from the center of the wind-spiking spoiler disk.

3. The composite heat dissipation system at the stator end of the high-speed motor according to claim 1, characterized in that, The spoiler ribs are arc-shaped ribs with a top view on the wind-sharp spoiler disk. The arc-shaped ribs extend radially outward from the center of the wind-sharp spoiler disk, and all the arcs have the same bending direction. According to the direction of the concave surface, they can be divided into forward-curved arcs in the same direction as the rotation direction and backward-curved arcs in the opposite direction.

4. The composite heat dissipation system at the stator end of the high-speed motor according to claim 1, characterized in that, The spoiler rib is a rib with an airfoil-shaped profile when viewed from above on the wind-spiking spoiler disk. The airfoil-shaped rib includes a leading edge and a trailing edge. The leading edge is arc-shaped and the trailing edge is pointed. The leading edge faces the center of the wind-spiking spoiler disk and is directed towards the air gap flow direction, while the trailing edge is radially away from the center of the wind-spiking spoiler disk.

5. The high-speed motor stator end composite heat dissipation system according to claim 1, characterized in that, The height of the bulge rib along the axial direction of the wind-piercing spoiler is 2-4 mm; the thickness of the wind-piercing spoiler is 2 mm.

6. The composite heat dissipation system at the stator end of the high-speed motor according to claim 1, characterized in that, The wind-piercing spoiler and the spoiler rib are integrally formed; the wind-piercing spoiler is detachably and fixedly connected to the rotor shaft by means of center interference fit, key connection or threaded locking.

7. The high-speed motor stator end composite heat dissipation system according to claim 6, characterized in that, A vibration damping bushing is provided between the inner wall of the center hole of the wind-piercing spoiler and the outer wall of the rotor shaft.

8. The composite heat dissipation system at the stator end of the high-speed motor according to claim 1, characterized in that, There are safety gaps between the wind-piercing spoiler and the end cover, and between the spoiler rib and the end of the stator winding. The design range of the safety gap is 2mm to 4mm. The outer diameter of the wind-piercing spoiler is smaller than the inner diameter of the housing.

9. A method for heat dissipation of a high-speed motor, characterized in that, The high-speed motor stator end composite heat dissipation system according to any one of claims 1-8 is used; the high-speed motor heat dissipation method includes the following steps: End heat accumulation and airflow diversion steps: When the high-speed motor is started, Joule heat is generated in the stator windings and accumulates at the ends of the stator windings, forming local hot spots; the high-speed rotation of the rotor drives the wind-piercing turbulence assembly, which is coaxially fixed on its rotor shaft, to rotate synchronously. As the rotor shaft rotates, the turbulence ribs of the wind-piercing turbulence assembly guide the airflow in the air gap between the rotor and the stator into axial turbulence airflow flowing along the rotor axis toward the end of the stator winding. At the same time, it applies shear disturbance to the airflow in the end annular cavity, causing the airflow in the end annular cavity to change from laminar flow to turbulent flow. Internal airflow heat exchange and heat transfer steps: The axial turbulent airflow impacts the end surface of the stator winding, causing the laminar thermal boundary layer on the end surface of the stator winding to transform into a turbulent boundary layer, and forming a circulating three-dimensional vortex in the annular cavity at the end. The three-dimensional vortex sweeps across the end surface of the stator winding at multiple angles, dissipating the heat accumulated at the end of the stator winding through convection heat transfer, and transferring the heat to the inner wall of the housing. Composite heat dissipation synergy and thermal balance maintenance process: The heat transferred to the inner wall of the casing is dissipated outward in two ways: one is carried out by the coolant in the liquid cooling channel through forced convection heat exchange, and the other is dissipated to the external environment through the heat dissipation fins through natural convection.

10. The high-speed motor heat dissipation method according to claim 9, characterized in that, It also includes the coolant introduction step: Before or during the rotation of the rotor, coolant is introduced into the inlet of the liquid cooling channel. After the coolant absorbs heat from the inner wall of the casing, it is discharged from the outlet of the liquid cooling channel.

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