A hybrid cooling outer rotor permanent magnet motor

Abstract

The present invention discloses a hybrid cooling outer rotor permanent magnet motor, and relates to the field of motors. Most existing outer rotor permanent magnet motors adopt single air cooling or liquid cooling, and the ability to improve the power density of the motor is limited. The present invention includes a stator and an outer rotor, the stator includes a stator support shaft, a stator core, and a stator winding, the outer rotor includes an outer rotor housing, a rotor permanent magnet and an end cover, an axial fan air inlet is provided on the end cover, an air outlet is provided at the lower part of the outer rotor housing, and a core liquid cooling circuit and a winding liquid cooling circuit are provided on the stator for cooling the stator core and the stator winding respectively. The heat generated by the stator armature winding and the stator core can be transferred through the core liquid cooling circuit and the winding liquid cooling circuit, and an air cooling channel is formed through the end cover air inlet, the outer rotor air outlet and the motor internal air duct. The mixed cooling method of these two cooling circuits can effectively improve the cooling effect, improve the motor power density, and reduce the volume and weight of the motor.

Description

Technical Field

[0001] The invention relates to the field of motors, and in particular to a hybrid cooling outer rotor permanent magnet motor. Background Art

[0002] At present, most of the existing outer rotor permanent magnet motors use single air cooling or liquid cooling, and the power density improvement ability of the motor is limited. In special application environments, it is necessary to reduce the weight of the motor as much as possible and improve the power density. Summary of the invention

[0003] The technical problem to be solved and the technical task proposed by the present invention are to improve and perfect the existing technical solutions and provide a hybrid cooling outer rotor permanent magnet motor for the purpose of reducing the weight of the motor and improving the power density. To this end, the present invention adopts the following technical solutions.

[0004] A hybrid cooling outer rotor permanent magnet motor comprises a stator and an outer rotor located outside the stator, wherein the stator comprises a stator support shaft, a stator core arranged on the stator support shaft, and a stator winding arranged on the stator core, the outer rotor comprises an outer rotor casing, a rotor permanent magnet arranged in the outer rotor casing, and an end cover arranged at the upper end of the outer rotor casing, the center of the end cover is rotatably connected to the stator support shaft through a rotor hollow shaft, a running gap exists between the outer periphery of the stator and the inner side of the rotor permanent magnet, the end cover is evenly distributed with axial flow fan air inlet holes, the lower part of the outer rotor casing is evenly distributed with air outlet holes, the air inlet holes, the air outlet holes and the air cooling channel inside the motor form an air cooling circuit, and the stator is provided with an iron core liquid cooling circuit and a winding liquid cooling circuit for cooling the stator core and the stator winding respectively. The heat generated by the stator armature winding and the stator core can be transferred through the core liquid cooling circuit and the winding liquid cooling circuit. The air cooling circuit is formed by the air inlet holes on the end cover, the air outlet holes at the bottom of the outer rotor casing and the air cooling channel inside the motor for air cooling and heat dissipation. The mixed cooling method of these two cooling circuits can effectively improve the cooling effect, increase the motor power density and reduce the motor volume and weight.

[0005] As a preferred technical means: the stator support shaft includes a vertical inner ring, a vertical outer ring, an annular flat ring arranged outside the lower end of the vertical outer ring, and a connecting ring connected between the vertical inner ring and the vertical outer ring. The rotor hollow shaft is rotatably connected to the stator support shaft through an upper bearing and a lower bearing. The outer rotor casing includes a casing body inlaid with the rotor permanent magnet in the middle and upper part and an annular cover plate arranged at the lower end of the casing body. The lower end of the annular cover plate is located outside the upper end of the annular flat ring, and there is a running gap between the annular flat ring and the stator support shaft. The stator support shaft has a simple structure and effectively realizes a rotatable connection with the rotor.

[0006] As the preferred technical means: the air inlet is directly opposite to the winding, the connecting ring is provided with vertical ventilation holes, the lower part of the connecting ring is provided with a wind shielding ring plate between the lower part of the vertical inner ring and the vertical outer ring, the vertical outer ring part between the connecting ring and the wind shielding ring plate is evenly distributed with through side holes, and the annular cover plate is evenly distributed with the air outlet holes. After the incoming axial wind enters the air inlet, it passes through the inner and outer sides of the winding diversion, the outer side passes downward through the winding and the gap between the stator and rotor, and then exits from the air outlet, and the inner side passes downward through the vertical ventilation holes. Due to the obstruction of the wind shielding ring plate below, the cooling wind can only pass through the through side holes laterally to cool the lower end of the stator core and the winding, and then exit from the air outlet, forming a complete air cooling circuit, which can effectively cool the rotor permanent magnet, stator core and stator winding, and has a good cooling effect.

[0007] As a preferred technical means: the iron core liquid cooling circuit comprises vertical iron core cooling pipes uniformly distributed around the iron core, the vertical iron core cooling pipes are connected in parallel or in series to form an iron core liquid cooling circuit, and liquid cooling medium is injected into the iron core liquid cooling circuit to effectively realize the iron core liquid cooling circuit.

[0008] As an optimal technical means: the vertical iron core cooling pipe is arranged in the outer peripheral wall of the vertical outer ring, and the outer side of the vertical iron core cooling pipe is in contact with the inner peripheral wall of the iron core, so that the iron core can be directly heat exchanged, and the cooling effect is good.

[0009] As a preferred technical means: the winding liquid cooling circuit comprises vertical winding cooling pipes uniformly distributed around, the vertical winding cooling pipes are connected in parallel or in series to form a winding liquid cooling circuit, and liquid cooling medium is injected into the winding liquid cooling circuit to effectively realize the winding liquid cooling circuit.

[0010] As an optimal technical means: each vertical winding cooling pipe is arranged between two adjacent stator windings, and the vertical winding cooling pipe is close to the windings on both sides, so that the windings can be directly heat exchanged, and the cooling effect is good.

[0011] As a preferred technical means: the core liquid cooling circuit and the winding liquid cooling circuit are made of non-magnetic conductive materials, which will not change the electromagnetic structure of the motor itself.

[0012] As a preferred technical means: the rotor permanent magnet is made of a plurality of small pieces of magnetic steel bonded by insulating adhesive, which can effectively reduce the eddy current loss of the magnetic steel.

[0013] As a preferred technical means: the stator support shaft and the iron core liquid cooling circuit are integrally formed by casting or 3D printing, which simplifies the manufacturing process and effectively saves the weight added by separately setting up cooling pipes.

[0014] As a preferred technical means: the outer rotor housing and the end cover are matched by a stopper. The stopper matching method is widely used and has accurate positioning.

[0015] As a preferred technical means: the stator core is formed by laminating silicon steel sheets or pressing iron powder, and adopts conventional manufacturing methods with low cost.

[0016] Beneficial effects: The heat generated by the stator armature winding and the stator core can be transferred through the core liquid cooling circuit and the winding liquid cooling circuit. The rotor permanent magnet, stator core and stator winding can be effectively cooled through the air cooling circuit. The mixed cooling method of these two cooling circuits can effectively improve the cooling effect, increase the motor power density, and reduce the motor volume and weight. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the 3D structure with a radial section of the present invention.

[0018] Figure 2 It is a horizontal cross-sectional schematic diagram of the present invention.

[0019] Figure 3 The present invention Figure 1 Enlarged schematic diagram of part A in the middle.

[0020] Figure 4 It is a schematic diagram of the air cooling circuit of the present invention.

[0021] In the figure: 1- stator support shaft; 2- stator core; 3- stator winding; 4- outer rotor casing; 5- rotor permanent magnet; 6- end cover; 7- rotor hollow shaft; 8- iron core liquid cooling circuit; 9- winding liquid cooling circuit; 10- wind shield ring plate; 11- upper bearing; 12- lower bearing; 101- vertical outer ring; 102- vertical inner ring; 103- connecting ring; 104- annular flat ring; 105- ventilation hole; 106- through side hole; 401- air outlet; 402- casing body; 403- annular cover plate; 601- air inlet. DETAILED DESCRIPTION

[0022] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings.

[0023] like Figure 1-4As shown, a hybrid cooling outer rotor permanent magnet motor comprises a stator and an outer rotor located outside the stator, the stator comprises a stator support shaft 1, a stator core 2 arranged on the stator support shaft 1, and a stator winding 3 arranged on the stator core 2, the outer rotor comprises an outer rotor casing 4, a rotor permanent magnet 5 arranged in the outer rotor casing 4, and an end cover 6 arranged at the upper end of the outer rotor casing 4, the center of the end cover 6 is rotatably connected to the stator support shaft 1 through a rotor hollow shaft 7, and there is a running gap between the outer periphery of the stator and the inner side of the rotor permanent magnet 5, the end cover 6 is evenly distributed with axial flow fan air inlet holes 601, the lower part of the outer rotor casing 4 is evenly distributed with air outlet holes 401, the air inlet holes 601, the air outlet holes 401 and the air cooling channel inside the motor form an air cooling circuit, and the stator is provided with an iron core liquid cooling circuit 8 and a winding liquid cooling circuit 9 for cooling the stator core 2 and the stator winding 3 respectively.

[0024] In order to realize the rotatable connection with the rotor, the stator support shaft 1 includes a vertical inner ring 102, a vertical outer ring 101, an annular flat ring 104 arranged outside the lower end of the vertical outer ring 101, and a connecting ring 103 connected between the vertical inner ring 102 and the vertical outer ring 101. The rotor hollow shaft 7 is rotatably connected to the stator support shaft 1 through an upper bearing 11 and a lower bearing 12. The outer rotor housing 4 includes a housing body 402 with a rotor permanent magnet 5 embedded in the middle and upper part and an annular cover plate 403 arranged at the lower end of the housing body 402. The lower end of the annular cover plate 403 is located outside the upper end of the annular flat ring 104, and there is a running gap between the annular flat ring 104. The stator support shaft 1 has a simple structure and effectively realizes the rotatable connection with the rotor.

[0025] In order to achieve a better air cooling effect, the air inlet 601 is opposite to the winding, a vertical ventilation hole 105 is provided on the connecting ring 103, and a wind shielding ring plate 10 is provided below the connecting ring 103 between the lower parts of the vertical inner ring 102 and the vertical outer ring 101, and the vertical outer ring 101 between the connecting ring 103 and the wind shielding ring plate 10 is evenly distributed with through side holes 106, and the annular cover plate 403 is evenly distributed with air outlet holes 401. After the incoming axial wind enters the air inlet hole 601, it passes through the inner and outer sides of the winding diversion, passes downward through the winding and the gap between the stator and rotor from the outside, and then exits from the air outlet hole 401, and passes downward through the vertical ventilation hole 105 from the inside. Due to the obstruction of the wind shielding ring plate 10 below, the cooling wind can only pass laterally through the side hole 106 to cool the stator core 2 and the lower end of the winding before exiting from the air outlet hole 401, forming a complete air cooling circuit, which can effectively cool the rotor permanent magnet 5, the stator core 2 and the stator winding 3, and the cooling effect is better.

[0026] In order to realize the iron core liquid cooling loop 8, the iron core liquid cooling loop 8 includes vertical iron core cooling pipes uniformly distributed around, and the vertical iron core cooling pipes are connected in parallel to form the iron core liquid cooling loop 8, and the liquid cooling medium is filled in the iron core liquid cooling loop 8. In order to effectively realize the iron core liquid cooling loop 8, in this example, a series connection method can also be used for replacement.

[0027] In order to better cool the iron core, the vertical iron core cooling pipe is arranged inside the outer peripheral wall of the vertical outer ring 101, and the outer side of the vertical iron core cooling pipe is in contact with the inner peripheral wall of the iron core, so that the iron core can be directly heat exchanged, and the cooling effect is better.

[0028] In order to realize the winding liquid cooling loop 9, the winding liquid cooling loop 9 includes vertical winding cooling pipes uniformly distributed around, and the vertical winding cooling pipes are connected in parallel to form the winding liquid cooling loop 9, and the liquid cooling medium is filled in the winding liquid cooling loop 9. In order to effectively realize the winding liquid cooling loop 9, in this example, a series connection can also be used for replacement.

[0029] In order to better cool the winding, each vertical winding cooling pipe is arranged between two adjacent stator windings 3, and the vertical winding cooling pipe is close to the windings on both sides, so that the winding can be directly heat exchanged, and the cooling effect is better.

[0030] In order not to change the electromagnetic structure of the motor itself, the core liquid cooling loop 8 and the winding liquid cooling loop 9 are made of non-magnetic conductive materials, which will not change the electromagnetic structure of the motor itself.

[0031] In order to reduce the eddy current loss of the magnetic steel, the rotor permanent magnet 5 is made of small pieces of magnetic steel bonded by insulating glue, which can effectively reduce the eddy current loss of the magnetic steel.

[0032] In order to reduce costs, the stator support shaft 1 and the iron core liquid cooling circuit 8 are integrally formed by casting. The manufacturing process is simplified, and the weight added by setting up a cooling pipeline separately can be effectively saved, and the cost can be reduced. In this example, the additive manufacturing method of 3D printing integrally formed can also be used instead.

[0033] In order to facilitate installation, the outer rotor housing 4 and the end cover 6 are matched by a stopper. The stopper matching method is widely used, easy to install and accurate in positioning.

[0034] In this example, the stator core 2 is formed by laminating silicon steel sheets, and may also be formed by pressing iron powder instead of laminating silicon steel sheets.

[0035] The heat generated by the stator armature winding and the stator core 2 can be transferred through the core liquid cooling circuit 8 and the winding liquid cooling circuit 9. The air cooling circuit composed of the air inlet hole 601 on the end cover 6, the air outlet hole 401 at the lower part of the outer rotor casing 4 and the air cooling channel inside the motor can effectively cool the rotor permanent magnet 5, the stator core 2 and the stator winding 3. The mixed cooling mode of these two cooling circuits can effectively improve the cooling effect, increase the power density of the motor, and reduce the volume and weight of the motor.

[0036] above Figure 1-4 The hybrid cooling outer rotor permanent magnet motor shown is a specific embodiment of the present invention, which has embodied the outstanding substantial features and significant progress of the present invention. According to actual use needs and under the guidance of the present invention, equivalent modifications in shape, structure, etc. can be made to it, which are all within the protection scope of this scheme.

Claims

1. A hybrid cooling outer rotor permanent magnet motor, comprising a stator and an outer rotor located outside the stator, characterized in that: The stator comprises a stator support shaft (1), a stator core (2) arranged on the stator support shaft (1), and a stator winding (3) arranged on the stator core (2); the outer rotor comprises an outer rotor casing (4), a rotor permanent magnet (5) arranged in the outer rotor casing (4), and an end cover (6) arranged at the upper end of the outer rotor casing (4); the center of the end cover (6) is rotatably connected to the stator support shaft (1) via a rotor hollow shaft (7); the outer periphery of the stator is rotatably connected to the rotor permanent magnet (5) and the outer periphery of the stator is rotatably connected to the rotor permanent magnet (5). (5), there is a running gap between the inner sides, the end cover (6) is evenly distributed with axial fan air inlet holes (601), the lower part of the outer rotor housing (4) is evenly distributed with air outlet holes (401), the air inlet holes (601), the air outlet holes (401) and the air cooling channel inside the motor form an air cooling circuit, and the stator is provided with an iron core liquid cooling circuit (8) and a winding liquid cooling circuit (9) for cooling the stator iron core (2) and the stator winding (3) respectively; The stator support shaft (1) comprises a vertical inner ring (102), a vertical outer ring (101), an annular flat ring (104) arranged outside the lower end of the vertical outer ring (101), and a connecting ring (103) connected between the vertical inner ring (102) and the vertical outer ring (101); the rotor hollow shaft (7) and the stator support shaft (1) are rotatably connected via an upper bearing (11) and a lower bearing (12); the outer rotor casing (4) comprises a casing body (402) inlaid with the rotor permanent magnet (5) at the middle and upper part, and an annular cover plate (403) arranged at the lower end of the casing body (402); the lower end of the annular cover plate (403) is located outside the upper end of the annular flat ring (104), and there is a running gap between the annular flat ring (104); The air inlet (601) is directly opposite to the winding, the connecting ring (103) is provided with vertical ventilation holes (105), a wind shielding ring plate (10) is provided below the connecting ring (103) and between the lower parts of the vertical inner ring (102) and the vertical outer ring (101), and penetrating side holes (106) are evenly distributed around the vertical outer ring (101) between the connecting ring (103) and the wind shielding ring plate (10), and the air outlet holes (401) are evenly distributed around the annular cover plate (403).

2. A hybrid cooling outer rotor permanent magnet motor according to claim 1, characterized in that: The iron core liquid cooling circuit (8) comprises vertical iron core cooling pipes evenly distributed around the iron core, and the vertical iron core cooling pipes are connected in parallel or in series to form an iron core liquid cooling circuit (8), in which liquid cooling medium is injected.

3. A hybrid cooling outer rotor permanent magnet motor according to claim 2, characterized in that: The vertical iron core cooling pipe is arranged inside the outer peripheral wall of the vertical outer ring (101), and the outer side of the vertical iron core cooling pipe is in contact with the inner peripheral wall of the iron core.

4. The hybrid cooling outer rotor permanent magnet motor according to claim 1, characterized in that: The winding liquid cooling circuit (9) comprises vertical winding cooling pipes that are evenly distributed around the winding, and the vertical winding cooling pipes are connected in parallel or in series to form a winding liquid cooling circuit (9), in which a liquid cooling medium is injected.

5. A hybrid cooling outer rotor permanent magnet motor according to claim 4, characterized in that: Each vertical winding cooling duct is arranged between two adjacent stator windings (3), and the vertical winding cooling duct is in contact with the windings on both sides.

6. The hybrid cooling outer rotor permanent magnet motor according to claim 1, characterized in that: The iron core liquid cooling circuit (8) and the winding liquid cooling circuit (9) are made of non-magnetic conductive materials.

7. The hybrid cooling outer rotor permanent magnet motor according to claim 1, characterized in that: The rotor permanent magnet (5) is formed by bonding a plurality of small pieces of magnetic steel by means of insulating adhesive.

8. The hybrid cooling outer rotor permanent magnet motor according to claim 1, characterized in that: The stator support shaft (1) and the iron core liquid cooling circuit (8) are integrally formed by casting or 3D printing.

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