Oil-cooled outer rotor motor

Abstract

The invention discloses an oil cooling external rotor motor, which comprises a casing and a rotating shaft, the casing is rotatably connected with the rotating shaft, a rotor assembly and a stator are arranged in the casing, the rotor assembly is fixedly connected with the rotating shaft, the stator is fixedly connected with the casing, and cooling oil is stored in the casing. And at least one part of the rotor assembly and at least one part of the stator are immersed in the cooling oil. The complexity of equipment can be reduced, and the cooling efficiency is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of motors, and particularly relates to an oil-cooled outer rotor motor. Background Art

[0002] In many fields, motors are widely used, and motor heat dissipation is a relatively important issue. At present, there is already an oil immersion cooling method for motors. For example, in a Chinese invention patent with the publication number CN112491197A and the patent name "An oil-cooled axial flux motor with an internal axial flow fan", this patent mainly uses an annular oil-cooled sleeve to separate the rotor assembly and the stator in the machine shell, so that the stator is accommodated in a sealed oil immersion chamber. The oil immersion chamber is composed of the first end cover and the second end cover at both ends, the inner wall of the machine shell, and the outer wall of the oil-cooled sleeve. Cooling oil is introduced through the oil inlet, and then the cooling oil passes through the axial channels provided in the stator core and flows out from the oil outlet, thereby realizing the oil cooling cycle. However, this oil immersion cooling method needs to be connected to an external cooling oil circulation system, increasing the complexity of the equipment. Summary of the Invention

[0003] In order to solve the above problems, the present invention provides an oil-cooled outer rotor motor, which can reduce the complexity of the equipment and improve the cooling efficiency.

[0004] The embodiments of the present invention are realized through the following technical solutions:

[0005] An oil-cooled outer rotor motor includes a machine shell and a rotating shaft. A rotor assembly and a stator are provided inside the machine shell. The stator is fixedly connected to the machine shell, and the rotor assembly is fixedly connected to the rotating shaft. Cooling oil is stored in the machine shell, and at least a part of the rotor assembly and the stator is immersed in the cooling oil. The rotor assembly includes a rotor fixedly connected to the rotating shaft. The rotor is provided with a first oil guiding hole, which communicates the inner side and the outer side of the rotor. A second oil guiding hole is provided at the connection between the stator and the machine shell, which communicates the inner side and the outer side of the stator.

[0006] In an embodiment of the present invention, a heat dissipation part is provided on the outer wall of the machine shell.

[0007] In an embodiment of the present invention, the rotor is of a barrel-shaped structure, and permanent magnets are installed on the barrel wall of the rotor. The first oil guiding hole is located on the end wall of the rotor.

[0008] In an embodiment of the present invention, the rotor is further provided with a stirring part for stirring the cooling oil.

[0009] In an embodiment of the present invention, the machine shell includes a stator seat, and the stator seat is rotatably connected to the rotating shaft through a bearing, and the stator is fixedly connected to the stator seat.

[0010] In an embodiment of the present invention, the stator includes a cylindrical wall and a high-pressure oil inlet ring; one end of the cylindrical wall is a low-pressure oil outlet end, the other end of the cylindrical wall is fixed to the high-pressure oil inlet ring, and the low-pressure oil outlet end corresponds to the first oil guiding hole; the high-pressure oil inlet ring is fixed to the stator base, and the high-pressure oil inlet ring is provided with a plurality of oil passing grooves. When the stator is fixed to the stator base, the oil passing grooves and the stator base enclose the second oil guiding hole.

[0011] In an embodiment of the present invention, the inner diameter of the high-pressure oil inlet ring is smaller than the inner diameter of the cylindrical wall, and a step is formed after the high-pressure oil inlet ring is fixed to the cylindrical wall.

[0012] In an embodiment of the present invention, the stator base is provided with a limiting ring, and the limiting ring cooperates with the rotor assembly to limit the installation position of the stator.

[0013] In an embodiment of the present invention, the machine shell further includes an end cover and an outer sealing ring cover; the end cover is parallel to the vertical surface of the stator base; the outer sealing ring cover is located between the end cover and the stator base, and the outer sealing ring cover is fixed to the end cover and the stator base respectively.

[0014] In an embodiment of the present invention, the rotating shaft is a hollow shaft.

[0015] The technical solution of the present invention has at least the following advantages and beneficial effects:

[0016] In the present invention, cooling oil is injected into the machine shell, and the rotor is used to splash the cooling oil at the bottom of the machine shell to the entire machine shell, and then the cooling oil flows back to the bottom of the machine shell to achieve the cooling of the motor. Compared with the prior art, the motor does not need to be connected to an external cooling oil filling system, but directly injects the cooling oil into the machine shell, reducing the complexity of the equipment and improving the cooling efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required in the embodiments. It should be understood that the following drawings only show some embodiments of the present invention, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0018] Figure 1 It is a schematic diagram of the connection between the oil-cooled outer rotor motor and the load transmission shaft in the present invention;

[0019] Figure 2 For Figure 1 the rear view schematic diagram of the oil-cooled outer rotor motor in

[0020] Figure 3 It is a cross-sectional view of the oil-cooled outer rotor motor in the present invention;

[0021] Figure 4 This is a cross-sectional view of the oil-cooled outer rotor motor in the present invention, omitting the outer sealing ring cover and the end cover;

[0022] Figure 5 This is a schematic diagram of the rotor in the oil-cooled outer rotor motor of the present invention;

[0023] Figure 6 This is a schematic diagram of the stator base and the stator in the oil-cooled outer rotor motor of the present invention;

[0024] Figure 7 This is a schematic diagram of the stator base in the oil-cooled outer rotor motor of the present invention;

[0025] Figure 8 This is a schematic diagram of the stator in the oil-cooled outer rotor motor of the present invention.

[0026] Icon: 1 - housing, 11 - stator base, elevation - 111, 12 - end cover, 13 - outer sealing ring cover, 14 - limiting ring, 2 - rotating shaft, 31 - rotor, 32 - stirring part, 4 - stator, 41 - oil passing groove, 42 - cylindrical wall, 43 - high-pressure oil inlet ring, 5 - support structure, 51 - motor bracket, 52 - connecting piece, 61 - first oil guiding hole, 62 - second oil guiding hole, 7 - heat dissipation part, 81 - motor winding coil, 82 - permanent magnet. Detailed implementation manners

[0027] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. Usually, the components of the embodiments of the present invention described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations.

[0028] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed present invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0029] It should be noted that: similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0030] In the description of the present invention, it should be noted that if terms such as "inner" and "outer" are used to indicate the orientation or positional relationship, which is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the invention product is usually placed during use, it is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention.

[0031] In the description of the present invention, it should also be noted that unless otherwise clearly specified and defined, if terms such as "set", "installed", "configured", "connected" are used, they should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0032] An oil-cooled outer-rotor motor includes a housing 1 and a rotating shaft 2. A rotor assembly and a stator 4 are provided inside the housing 1. The stator 4 is fixedly connected to the housing 1, and the rotor assembly is fixedly connected to the rotating shaft 2. Cooling oil is stored inside the housing 1, and at least a part of the rotor assembly and the stator 4 is immersed in the cooling oil; the rotor assembly includes a rotor 31 fixedly connected to the rotating shaft 2, and the rotor 31 is provided with a first oil guiding hole 61, and the first oil guiding hole 61 communicates the inner side and the outer side of the rotor 31; a second oil guiding hole 62 is provided at the connection between the stator 4 and the housing 1, and the second oil guiding hole 62 communicates the inner side and the outer side of the stator 4.

[0033] The following embodiment solutions are elaborated in detail based on the above solutions.

[0034] Embodiment

[0035] Please refer to Figures 1-3, this embodiment provides an oil-cooled outer rotor motor, which includes a housing 1 and a rotating shaft 2. The housing 1 is rotatably connected to the rotating shaft 2. A rotor assembly and a stator 4 are arranged inside the housing 1. The rotor assembly is fixedly connected to the rotating shaft 2, and the stator 4 is fixedly connected to the housing 1. Specifically, the housing 1 includes a stator base 11, an end cover 12, and an outer sealing ring cover 13. The end cover 12 is parallel to the vertical surface 111 of the stator base 11. The outer sealing ring cover 13 is located between the end cover 12 and the stator base 11, and the outer sealing ring cover 13 is fixedly connected to the end cover 12 and the stator base 11 respectively. The stator base 11 is rotatably connected to the rotating shaft 2 through a bearing. A circular hole is provided at the center of the end cover 12. When the stator base 11 and the rotating shaft 2 are assembled, one end of the rotating shaft 2 passes through the circular hole of the end cover 12. Since the end cover 12 remains stationary when the rotating shaft 2 rotates, a gap is left between the end cover 12 and the rotating shaft 2 to avoid movement interference between the end cover 12 and the rotating shaft 2. The stator 4 is fixed on the stator base 11. A motor winding coil 81 is installed on the stator 4. The rotor assembly includes a rotor 31 fixedly connected to the rotating shaft 2. The rotor 31 is of a barrel-shaped structure, and permanent magnets 82 are installed on the barrel wall of the rotor 31.

[0036] It should be noted that, please refer to Figure 6 and Figure 7 , a limit ring 14 is provided on the stator base 11. By cooperating the limit ring 14 with the stator 4, the installation position of the stator 4 is limited to ensure that the coaxiality between the stator 4 and the rotating shaft 2 meets the accuracy requirements. At the same time, by limiting the installation position of the stator 4 through the limit ring 14, the relative positional relationship between the stator 4 and the rotor 31 is ensured.

[0037] It should be noted that the rotating shaft 2 can be a hollow shaft or a solid shaft. When the rotating shaft 2 is a hollow shaft, the drive shaft of the load can be connected to the hollow shaft through a key connection. When the rotating shaft 2 is a solid shaft, the drive shaft of the load can be connected to the solid shaft through a gear drive, a belt drive, or a coupling.

[0038] It should be noted that when the motor is in use, in order to provide a force application point for the motor, a support structure 5 is provided on the housing 1. One end of the support structure 5 is fixedly connected to the stator base 11, and the other end is connected to a load device, the ground, or other fixed points. Specifically, please refer to Figure 1 and Figure 3 , the support structure 5 includes a motor bracket 51 and a connecting member 52. The connecting member 52 is fixedly connected to a load device, the ground, or other fixed points. One end of the motor bracket 51 is connected to the connecting member 52, and the other end of the motor bracket 51 is fixedly connected to the stator base 11 to provide a force application point for the motor.

[0039] Please refer to Figures 1-8, to achieve the cooling of the motor, cooling oil is stored in the housing 1. That is, an oil injection port is provided on the end cover 12, the stator base 11 or the outer sealing ring cover 13, and the cooling oil is poured into the housing 1 through the oil injection port. Moreover, at least a part of the rotor 31 and the stator 4 are immersed in the cooling oil to ensure that the cooling oil can be stirred when the rotor 31 rotates. In this embodiment, the cooling oil in the housing 1 accounts for half of the volume inside the housing 1, and the rotor 31 is provided with a number of first oil guiding holes 61. Please refer to Figure 5 , to enable the rotor 31 to better drive the cooling oil to rotate, the rotor 31 is provided with a stirring part 32 for stirring the cooling oil. The stirring part 32 can adopt a stirring rod or other structures that can realize stirring the cooling oil. In this embodiment, the stirring part 32 adopts a stirring rod, such as Figure 5 shown, the stirring rod is a straight rod-shaped structure arranged parallel to the axis of the motor. One end of it is fixed on the bottom surface of the barrel-shaped outer rotor 31, and the other end extends towards the stator 4 to the inner cavity of the stator. Its position in the radial direction of the barrel-shaped outer rotor 31 matches the height of the cooling oil liquid level in the use state, and a number of stirring rods are provided. When the rotor 31 rotates, the cooling oil in the stator 4 rotates at a high speed along the inner wall of the stator 4, forming a high-speed rotating oil ring.

[0040] Please refer to Figures 6-8 , the stator 4 includes a cylindrical wall 42 and a high-pressure oil inlet ring 43. One end of the cylindrical wall 42 is a low-pressure oil outlet end, and the other end is fixed to the high-pressure oil inlet ring 43. The low-pressure oil outlet end corresponds to the first oil guiding hole 61 of the rotor 4, and the high-pressure oil inlet ring is fixed to the stator base 11 by bolts or other means to realize the fixation of the stator 4 and the stator base 11. Moreover, the high-pressure oil inlet ring 43 is provided with a number of oil passing grooves 41. After the stator 4 and the stator base 11 are fixed, the oil passing grooves 41 and the stator base 11 enclose and form a second oil guiding hole 62, and the second oil guiding hole 62 communicates the inside and the outside of the stator 4. Importantly, the inner diameter of the high-pressure oil inlet ring 43 is smaller than the inner diameter of the cylindrical wall 42, so that a step is formed after the high-pressure oil inlet ring 43 and the cylindrical wall 42 are fixed, and the cross section of the stator 4 is in an L shape. When the rotor 31 rotates at a high speed, the stirring rod drives the cooling oil to rotate at a high speed along the inner wall of the stator 4, forming a high-speed rotating oil ring. Due to the blockage of the high-pressure oil inlet ring of the stator 4, the oil ring cannot cross the high-pressure oil inlet ring and flow out of the stator 4 from the second oil guiding hole 62. It should be noted that, for the convenience of describing the structure of the stator 4, the structural names of the cylindrical wall 42 and the high-pressure oil inlet ring 43 are used in the stator 4, but the stator 4 is an integrally formed structure and is not composed of two parts combined.

[0041] Please refer to Figure 3Since the matching gap between the motor winding coil 81 and the permanent magnet 82 is very small, an approximately closed space is formed between the stator 4 and the rotor 31. When the rotor 31 rotates at high speed, the cooling oil rotates at high speed along the inner wall of the stator 4 under the drive of the stirring rod, and at the same time, part of the cooling oil rotates with the rotor 31 on the inner wall of the rotor 31, so that an internal oil ring rotating at high speed is formed in the approximately closed space between the stator 4 and the rotor 31, and has a high pressure. An external oil ring rotating at high speed is also formed outside the stator 4 and the rotor 31. Due to the obstruction of the high-pressure oil inlet ring of the stator 4, the internal oil ring cannot pass through the high-pressure oil inlet ring and flow from the smaller second oil guide hole 62 to the outside of the stator 4. At the same time, the fitting gap between the motor winding coil 81 and the permanent magnet 82 is very small, and the internal oil ring with higher pressure cannot flow out in large quantities from the fitting gap between the motor winding coil 81 and the permanent magnet 82. Therefore, the internal oil ring with higher pressure between the stator 4 and the rotor 31 can only flow out from the first oil guide hole 61 with a larger opening, enter the outside of the stator 4 and the rotor 31, and merge with the external oil ring. After the confluence, the amount of oil in the outer oil ring increases. Since the pressure in the space of the casing is balanced as a whole, in order to balance the pressure of the inner and outer oil rings, the cooling oil of the gradually pressurized outer oil ring enters the stator 4 from the second oil guide hole 62. At the same time, since the second oil guide hole 62 has a small aperture, the flow rate of the cooling oil increases when passing through the second oil guide hole 62, further increasing the pressure. When the cooling oil enters the stator 4, the pressure is reduced due to the increase in space, and it merges with the inner oil ring. At this point, the cooling oil in the casing forms such a circulation path: the inner oil ring between the stator 4 and the rotor 31 flows out from the first oil guide hole 61 at the low-pressure oil outlet end, merges with the outer oil ring outside the stator 4 and the rotor 31, and then enters the inside of the stator 4 and the rotor 31 from the second oil guide hole 62 on the side of the high-pressure oil inlet ring, and merges with the inner oil ring. During the oil circulation process, the heat generated by the motor winding coil 81 is taken away by the cooling oil, and the heat of the cooling oil is then heat-exchanged with the casing, and the casing is then heat-exchanged with the external environment, thereby achieving heat dissipation. It should be emphasized that, since the inner diameter corresponding to the outlet of the second oil guide hole 62 is small and the outer diameter corresponding to the first oil guide hole 61 is large, the cooling oil forms a pressure difference between the first oil guide hole 61 and the second oil guide hole 62 under the action of centrifugal force, and the oil cannot flow from the first oil guide hole 61 through the oil groove to the second oil guide hole 62 side, but can only flow from the second oil guide hole 62 side through the oil groove to the first oil guide hole 61 side. Only when the inner diameter is small and the outer diameter is large can a pressure difference be formed, and the cooling oil can be self-circulated.

[0042] It should be noted that the distance between the stirring rod and the inner wall of the cylindrical wall 42 of the stator 4 cannot be too large. If the distance is too large, the high-speed rotating oil ring formed on the inner wall of the stator 4 cannot contact the stirring rod, and it cannot provide power for the oil ring, resulting in the oil ring cannot be formed.

[0043] During the operation of the motor, in order to improve the heat dissipation efficiency of the motor housing 1, at least one of the stator base 11, the end cover 12 and the outer sealing ring cover 13 is provided with a heat dissipation part 7. The heat dissipation part 7 can adopt heat dissipation strips, heat dissipation fins or other heat dissipation structures. In this embodiment, the heat dissipation part 7 adopts heat dissipation strips to increase the contact area between the motor housing 1 and the external environment and improve the heat dissipation efficiency of the motor housing 1.

[0044] It should be noted that, in order to avoid oil leakage at the gap between the stator base 11 and the rotating shaft 2 and at the gap between the end cover 12 and the rotating shaft 2, oil seals are installed between the stator base 11 and the rotating shaft 2 and between the end cover 12 and the rotating shaft 2.

[0045] In the present invention, cooling oil is injected into the motor housing 1, and the rotor 31 is used to splash the cooling oil at the bottom of the motor housing 1 to the entire motor housing 1 and then flow back to the bottom of the motor housing 1 to achieve the cooling of the outer rotor motor. Compared with the prior art, the outer rotor motor does not need to be connected to an external cooling oil filling system, but directly fills the cooling oil into the motor housing 1, reducing the complexity of the equipment and improving the cooling efficiency.

[0046] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An oil-cooled outer rotor motor, comprising a housing and a rotating shaft. A rotor assembly and a stator are arranged inside the housing, and the stator is fixedly connected to the housing. It is characterized in that, The rotor assembly is fixedly connected to the rotating shaft. Cooling oil is stored in the machine housing, and at least a part of the rotor assembly and the stator are immersed in the cooling oil; The rotor assembly includes a rotor fixedly connected to the rotating shaft. The rotor is provided with a first oil guiding hole that communicates the inner and outer sides of the rotor; A second oil guiding hole is provided at the connection between the stator and the machine housing, and the second oil guiding hole communicates the inner and outer sides of the stator.

2. The oil-cooled outer rotor motor according to claim 1, characterized in that, A heat dissipation part is provided on the outer wall of the machine housing.

3. The oil-cooled outer rotor motor according to claim 1, wherein The rotor is of a barrel-shaped structure. Permanent magnets are installed on the barrel wall of the rotor, and the first oil guiding hole is located on the end wall of the rotor.

4. The oil-cooled outer rotor motor according to claim 1, characterized in that, The rotor is further provided with a stirring part for stirring the cooling oil.

5. The oil-cooled outer rotor motor according to claim 1, characterized in that, The machine housing includes a stator seat that is rotatably connected to the rotating shaft through a bearing, and the stator is fixedly connected to the stator seat.

6. The oil-cooled outer rotor motor according to claim 5, wherein, The stator includes a cylindrical wall and a high-pressure oil inlet ring; one end of the cylindrical wall is a low-pressure oil outlet end, the other end of the cylindrical wall is fixedly connected to the high-pressure oil inlet ring, and the low-pressure oil outlet end corresponds to the first oil guiding hole; the high-pressure oil inlet ring is fixedly connected to the stator seat, and the high-pressure oil inlet ring is provided with a plurality of oil passing grooves. When the stator is fixedly connected to the stator seat, the oil passing grooves and the stator seat enclose to form the second oil guiding hole.

7. The oil-cooled outer rotor motor according to claim 6, characterized in that, The inner diameter of the high-pressure oil inlet ring is smaller than the inner diameter of the cylindrical wall, and a step is formed after the high-pressure oil inlet ring is fixedly connected to the cylindrical wall.

8. The oil-cooled outer rotor motor according to claim 5, characterized in that, The stator seat is provided with a limiting ring that cooperates with the stator to limit the installation position of the stator.

9. The oil-cooled outer rotor motor according to claim 5, characterized in that, The machine housing further includes an end cover and an outer sealing ring cover; the end cover is parallel to the vertical surface of the stator seat; the outer sealing ring cover is located between the end cover and the stator seat, and the outer sealing ring cover is fixedly connected to the end cover and the stator seat respectively.

10. A liquid-cooled outer rotor motor according to any one of claims 1-9, characterized in that, The rotating shaft is a hollow shaft.

Images