Stator bushing structure for oil-cooled motor

Abstract

The utility model relates to a stator bushing structure used for an oil-cooled motor, a stator bushing is sleeved outside a stator of a motor system and used for isolating the motor system from a control system above the motor system, the stator bushing is connected with a motor shell through a flange, the stator bushing is cylindrical, and the stator bushing is provided with an oil-cooled motor. One end of the outer surface of the stator bushing is provided with a spigot, the middle part and the other end of the outer surface of the stator bushing are respectively provided with an O-shaped ring setting groove, and the stator bushing is contacted with the motor shell through the mounting flange surface and the spigot, so that the contact area of the stator and the motor shell is smaller than 10% of the area of a heating area of the stator, and the heat conducted to the shell through the stator bushing is greatly reduced. And the heat cannot be conducted to the control system above, so that the heat management safety of a controller chip in the control system is protected. And the smooth wall surface in the stator bushing is attached to the iron core outer ring oil duct. And under the high-temperature condition, the thermal expansion coefficient of the aluminum shell can expand the gap between the aluminum shell and the lining, heat conduction is isolated, and the heat conduction influence on the controller under the high-temperature working condition is reduced.

Description

Technical Field

[0001] This utility model relates to the technical field of electric motors, specifically to a stator bushing structure for oil-cooled motors, and more particularly to a stator bushing structure that enables a more efficient oil-cooling circulation system and simultaneously isolates the motor system and the control system. Background Technology

[0002] The motor and control systems are core components of electric vehicles, responsible for converting electrical energy into mechanical energy and precisely controlling the motor's operation. In existing technologies, the internal heat dissipation structures of oil-cooled motors suffer from mutual interference. Control systems typically use water cooling, which is unsuitable for contact with oil or gas, while the motor system's interior cannot come into contact with cooling water, as this would cause insulation problems. Therefore, the motor and control systems generally need to be separate and independent, but this inevitably increases the overall size and weight of the device. Furthermore, because they are independent, separate external cables are required for connection. High-power motor cables often have large diameters, are heavy, and are difficult to bend, further increasing the overall size and weight, making the internal volume and space layout issues particularly prominent.

[0003] On the one hand, the stator of the motor system is a high-heat component during the operation of a heavy-duty vehicle, and its internal cooling system can affect the cooling performance of other components within the system. If the stator is placed far away from other components within the housing, the motor controller will be too large, making it impossible to achieve a compact vehicle design, further affecting vehicle performance.

[0004] On the other hand, oil-cooled motors typically use the casing as the main carrier for the oil channels. However, the oil channels require high precision; otherwise, internal oil leakage will increase, reducing heat dissipation efficiency. The casing is usually made of aluminum, which, besides requiring high machining precision and being difficult to manufacture, also results in a significant difference in thermal expansion coefficients between the iron core and the aluminum casing at high motor temperatures. This thermal expansion further exacerbates internal oil leakage and reduces oil cooling efficiency.

[0005] Therefore, there is an urgent need for a structure to isolate the heat conduction efficiency of the motor stator, so that the motor stator is effectively isolated from other components, reducing the heat conduction efficiency, allowing the motor stator and controller to coexist in one cavity without affecting their own heat dissipation efficiency, and ultimately controlling the overall size of the motor. Summary of the Invention

[0006] The purpose of this invention is to provide an improved stator bushing structure for oil-cooled motors. Through structural improvements, the stator bushing is fitted onto the outside of the motor stator, replacing the conventional oil-cooled aluminum housing, thus forming a closed oil passage for the motor stator. This simultaneously isolates the heat from the motor and control system, reducing the heat conduction effect of the motor system and preventing internal leakage of cooling oil from the motor stator core.

[0007] To achieve the above objectives, the technical solution of this utility model is: a stator bushing structure for an oil-cooled motor, comprising a motor housing, characterized in that: the stator bushing is fitted outside the stator of the motor to isolate the motor system and the control system above the motor system, blocking heat transfer between the two; the stator bushing and the motor housing are connected by a flange; the stator bushing is cylindrical; one end of the outer surface of the stator bushing is provided with a stop; the middle and the other end are respectively provided with O-ring mounting grooves; the stator bushing contacts the motor housing through the mounting flange surface and the stop, such that the contact area between the stator and the motor housing is less than 10% of the area of ​​the heating region of the stator.

[0008] Preferably, the stator bushing material is stainless steel or other steel materials to ensure that the coefficient of thermal expansion is the same as or close to that of the iron core. The inner wall of the bushing has a smooth surface, and the inner wall of the bushing fits with the outer circle of the iron core, so that the oil passages on the surface of the outer circle of the iron core form a closed oil circuit.

[0009] Preferably, the inner wall of the stator bushing is provided with a positioning keyway for assembling the motor stator, and one end of the stator bushing is provided with an outwardly flanged mounting surface for mounting a flange.

[0010] Furthermore, the stator bushing has an oil inlet and an oil outlet in the middle section, and raised O-ring grooves are provided on both sides of the oil inlet and the oil outlet.

[0011] Furthermore, the other end of the stator bushing is provided with a nozzle, and the stator bushing is provided with an O-ring setting groove that mates with the nozzle.

[0012] Furthermore, an O-ring is installed in the O-ring groove. The outer diameter of the O-ring groove and the motor housing are in clearance fit, with the clearance value ranging from 0.05 to 0.3 mm. The top of the O-ring abuts against the motor housing, and the clearance value between the other parts of the stator bushing outer diameter and the motor housing is greater than 2 mm. The stator bushing is an integral structure.

[0013] Compared with the prior art, the technical solution of this utility model not only improves the overall technical solution, but also includes many detailed improvements. Specifically, it has the following beneficial effects:

[0014] 1. In the improved solution described in this utility model, the stator bushing is fitted outside the stator of the motor to isolate the motor system and the control system above the motor system, and to block the heat transfer between the two. The stator bushing is connected to the motor housing through a flange. The stator bushing contacts the motor housing through the mounting flange face and the stop, so that the contact area between the stator and the motor housing is less than 10% of the area of ​​the heat-generating area of ​​the stator. The bushing of the iron core part of the main heat-generating area is completely physically isolated from the housing, which greatly reduces the heat conduction effect during the heat dissipation process of the motor, ensures that the control system on the top of the motor is not affected by the heat of the stator, and makes the overall motor system structure layout more compact.

[0015] 2. The smooth inner wall of the stator bushing allows for a better fit with the oil channels on the outer ring of the iron core. During motor operation, the heat generated by the iron core itself and the windings can reach hundreds of degrees Celsius when conducted to the bushing. At this temperature, the similar coefficients of thermal expansion reduce changes in the fit clearance, mitigating the risk of increased clearance due to large differences in thermal expansion, which would lead to increased oil leakage and reduced cooling efficiency of the oil cooling system. Furthermore, the bushing and housing are sealed with O-rings, preventing metal-to-metal contact. At high temperatures, the coefficient of thermal expansion of the aluminum housing increases the gap with the bushing, further isolating the bushing from heat conduction to the aluminum housing and further reducing the impact of heat conduction on the controller under high-temperature conditions.

[0016] 3. In the technical solution of this utility model, the stator bushing is cylindrical, and one end of the outer surface of the stator bushing is provided with a stop, and the middle and the other end are respectively provided with O-ring setting grooves. The outer diameter of the O-ring setting groove is clearance-fitted with the motor housing, which further reduces the contact area between the stator bushing and the motor housing, so that the heat dissipation structure inside the motor does not affect each other and ensures the heat dissipation effect.

[0017] 4. In the structure of this utility model, the stator bushing is an integrated structure, fitted onto the outside of the stator. The inner wall of the stator bushing is provided with a positioning keyway for assembling the motor stator. The clearance fit at the O-ring position allows for easy installation and disassembly of the stator assembly. The overall structure is compact and reasonable, effectively isolating and separating the stator's oil cooling system from the controller's water cooling system, while also ensuring a miniaturized overall structure, optimizing the internal space layout of the motor, and facilitating future maintenance and upkeep.

[0018] 5. This utility model has a simple structure, reasonable layout, is easy to use, has outstanding heat insulation effect, and is easy to promote and utilize. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of this utility model.

[0020] Figure 2 This is a partial structural schematic diagram of the present invention.

[0021] Figure 3 This is a structural schematic diagram of an embodiment of the present utility model.

[0022] Figure 4 This is a schematic diagram of the usage state of this utility model.

[0023] Figure 5 This is another schematic diagram of the usage state of this utility model.

[0024] Figure label:

[0025] 1. Motor housing; 2. Motor system; 3. Control system; 4. Stator bushing;

[0026] 41. Locating keyway; 42. Stop; 43. O-ring setting groove; 44. Mounting flange face. Detailed Implementation

[0027] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0028] This utility model provides a stator bushing structure for an oil-cooled motor, including a motor housing 1, see details below. Figure 1 The difference between this and existing technologies lies in the following: the stator bushing 4 is fitted outside the stator of the motor to isolate the motor system 2 and the control system 3 above the motor system, ensuring complete physical metal-to-metal isolation between the two in the heating area of ​​the iron core. The stator bushing 4 is connected to the motor housing 1 via a flange. The stator bushing is cylindrical, with a stop 42 at one end of its outer surface, and O-ring grooves 43 at the middle and the other end. The stator bushing contacts the motor housing 1 through the mounting flange surface 44 and the stop, while other metal parts do not contact each other, ensuring that the contact area between the stator and the motor housing is less than 10% of the heating area of ​​the stator. The stator iron core or armature assembly is installed inside the stator bushing. The inner wall of the stator bushing has a smooth surface, and a closed oil channel is formed between the inner wall of the stator bushing and the outer circle of the stator iron core, improving heat dissipation efficiency.

[0029] In practice, because the four stator bushings are set on the outside of the stator, completely enclosing the entire stator, the motor stator and the control system above the motor system are completely physically isolated by metal, thus achieving the effect of temperature isolation. After setting the stator bushings, less than 10% of the heat-generating area of ​​the stator is in contact with the motor housing. In this way, the heat generated by the stator during operation is greatly reduced from being conducted to the motor housing through the stator bushings. This ensures that the heat generated by the stator during operation will not be conducted to the control system above, ensuring that the heat dissipation structure inside the motor does not affect each other, thereby protecting the thermal management safety of the controller chip in the control system.

[0030] Example 1

[0031] In this embodiment, a stator bushing structure for an oil-cooled motor is described, including a motor housing 1, wherein the stator bushing 4 is sleeved on the outside of the stator of the motor system, so that the motor stator and the control system above the motor system are completely physically isolated on the metal, thereby achieving the effect of temperature isolation.

[0032] Specifically, the stator bushing 4 is connected to the motor housing 1 via a flange. The stator bushing is cylindrical, with a stop 42 at one end of its outer surface and O-ring grooves 43 at the middle and the other end. The stator bushing only contacts the motor housing 1 through the mounting flange surface 44 and the stop 42, ensuring that the contact area between the stator and the motor housing is less than 10% of the heat-generating area of ​​the stator. This guarantees that most of the heat generated during stator operation will not be conducted to the motor housing through the stator bushing, nor will it be further conducted to the control system above the motor stator. In this way, the heat dissipation structures between the motor system and the control system will not affect each other, ensuring the heat dissipation effect inside the motor.

[0033] Furthermore, the inner wall of the stator bushing is provided with a positioning keyway 41 for assembling the motor stator, so that the motor stator and the stator bushing form an effective fit and a tight engagement, ensuring a stable connection between the two during motor operation and ensuring safety in use.

[0034] One end of the stator bushing has an outwardly flanged mounting surface 44 with several mounting holes for mounting the flange. The middle section of the stator bushing has oil inlet and outlet ports, with raised O-ring grooves 43 on both sides of the ports. The other end of the stator bushing has a nozzle, and the stator bushing has an O-ring groove that mates with the nozzle.

[0035] Furthermore, an O-ring seal is installed within the O-ring groove. The outer diameter of the O-ring groove and the motor housing have a clearance fit, with the clearance value ranging from 0.05-0.3mm. This clearance reduces heat conduction between the stator bushing and the motor housing. The top of the O-ring seal abuts against the motor housing. This clearance fit at the O-ring position allows for easy installation and removal of the stator assembly. The stator bushing is an integrated structure, making the motor system more compact, optimizing the internal space layout of the motor, and facilitating future maintenance and upkeep.

[0036] Example 2

[0037] This embodiment describes a stator bushing structure for an oil-cooled motor. The stator bushing is fitted over the stator of the motor system to isolate the temperature transfer between the motor system 2 and the control system 3 above it, achieving physical metal-to-metal isolation. The stator bushing is connected to the motor housing via a flange. The stator bushing is cylindrical, with a stop 42 at one end of its outer surface and O-ring grooves 43 at the middle and other ends. The stator bushing contacts the motor housing 1 through the mounting flange and the stop, ensuring that the contact area between the stator and the motor housing is less than 10% of the stator's heat-generating area. This significantly reduces the amount of heat generated by the stator during operation that is conducted to the housing through the stator bushing. This further reduces heat transfer to the cooling water channels, effectively reducing the possibility of heat transfer to the controller chip and protecting the thermal management safety of the controller chip.

[0038] Specifically, the aforementioned O-ring groove is equipped with an O-ring seal. The O-ring groove and the housing are in a clearance fit, not directly connected to the housing structure, which effectively reduces heat conduction between the stator bushing and the housing. The stator bushing 4 has an oil inlet and outlet in the middle, and three O-ring grooves that mate with the oil inlet and outlet. The O-ring grooves are arranged on both sides of the oil inlet and outlet, and O-ring seals are installed in the O-ring grooves to seal the oil inlet and outlet, so that the cooling oil inside the stator forms a cooling circuit only within the stator core and does not leak.

[0039] The smooth inner wall of the stator bushing creates a better fit with the oil channels on the outer ring of the iron core. During motor operation, the heat generated by the iron core itself and the windings can reach hundreds of degrees Celsius when conducted to the bushing. At this temperature, the similar coefficients of thermal expansion reduce changes in the fit clearance, mitigating the risk of increased clearance due to large differences in thermal expansion, which would lead to increased leakage in the oil circuit and reduce the cooling efficiency of the oil cooling system. Furthermore, the bushing and housing are sealed with O-rings, preventing metal-to-metal contact. At high temperatures, the coefficient of thermal expansion of the aluminum housing increases the gap between it and the bushing, further isolating the bushing from heat conduction to the aluminum housing and further reducing the impact of heat conduction on the controller under high-temperature conditions.

[0040] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications or substitutions should be considered within the protection scope of the present invention.

Claims

1. A stator liner structure for an oil-cooled electric machine comprising a machine housing, characterized by: The stator bushing is sleeved outside the stator of the motor system to isolate the motor system and a control system above the motor system, and is connected with the motor housing through a flange. The stator bushing is in a cylindrical shape, and an end of an outer surface of the stator bushing is provided with a stopper, and a middle part and the other end are respectively provided with O-ring setting grooves. The stator bushing is in contact with the motor housing through the mounting flange surface and the stopper, so that the contact area of the stator and the motor housing is less than 10% of the heating area of the stator.

2. A stator sleeve structure for an oil-cooled electric machine according to claim 1, characterized in that: The inner side wall of the stator bushing is provided with a positioning key groove to assemble the motor stator. An end of the stator bushing is provided with an outwardly turned flange mounting surface for mounting the flange.

3. A stator sleeve structure for an oil-cooled electric machine according to claim 1, characterized in that: The middle part of the stator bushing is provided with an oil inlet and an oil outlet, and the two sides of the oil inlet and the oil outlet are provided with protruding O-ring setting grooves.

4. A stator sleeve structure for an oil-cooled electric machine according to claim 1, characterized in that: The other end of the stator bushing is provided with a nozzle, and the stator bushing is provided with an O-ring setting groove matched with the nozzle.

5. A stator sleeve structure for an oil-cooled electric machine according to claim 1, characterized in that: An O-ring is arranged in the O-ring setting groove, and the outer diameter of the O-ring setting groove is in clearance fit with the motor housing. The clearance value is in the range of 0.05-0.3 mm, and the top of the O-ring is in abutment with the motor housing.

6. A stator sleeve structure for an oil-cooled electric machine according to claim 1, characterized in that: The stator bushing is in an integrated structure, the material of the stator bushing is stainless steel, the inner wall of the bushing is a smooth surface, and the inner wall of the bushing and the outer circle of the iron core form a closed oil path.

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