JP5931460B2 - Outer rotor type brushless motor - Google Patents

Description

  The present invention relates to an outer rotor type brushless motor.

  Generally, an outer rotor type brushless motor includes a stator and a rotor that is rotatably disposed outside the stator. The stator includes a stator core and a coil, and the stator core is formed of a substantially annular core body and a plurality of teeth integrally formed on the outer wall of the core body, and the coil is wound around the teeth of the stator. The rotor includes a rotor main body and a magnet. The rotor main body is formed in a substantially low-cylindrical shape by a bottom portion that closes the opening of the cylindrical portion and the cylindrical portion, and is rotatable around one side of the stator core and surrounding the stator. The magnet is provided on the inner wall of the cylinder portion of the rotor body so as to face the stator.

  Such an outer rotor type brushless motor can increase the volume of the magnet as compared with the inner rotor type, and can increase the effective magnetic flux of the motor. Therefore, the outer rotor type brushless motor has a feature that the output performance per unit volume is higher than that of the inner rotor type, and the size and cost are reduced. As an application example in which the above features can be utilized, a drive motor for an electric vehicle or an electric motorcycle can be considered.

  Here, a drive motor of an electric vehicle or the like has a larger output than a small motor (for example, a wiper motor or a power window motor) used for auxiliary machinery such as an automobile. In general, the rated output of a drive motor for an electric motorcycle is several kW, and the rated output of the drive motor for an electric vehicle is several tens kW. Therefore, if the efficiency of the motor is 90%, there is a high level of heat loss of several hundred watts for electric motorcycles and a few kW level for electric automobiles, and the drive motor generates heat due to this high level of heat loss. Due to this heat generation, the driving motor becomes hot.

  Therefore, drive motors such as electric vehicles need to be constantly cooled. And as a cooling method, there are a “water cooling method” and an “air cooling method”.

Here, in the “water cooling system”, piping for supplying cooling water to the motor, a heat exchanger, and a pump for circulating the cooling water are required, and the number of parts is complicated, the structure is complicated, and the cost is increased. is there.

The “air cooling method” includes 1) “natural air cooling method” and 2) “forced air cooling method”. Here, 1) The “natural air cooling system” has a problem that the structure has a simple structure but the amount of heat released is small. On the other hand, 2) “forced air cooling method” is, for example, as shown in Patent Document 1, in which a vent hole is formed in the motor case, and outside air is introduced into the motor case through the vent hole by a fan provided in the motor. This is a system in which the motor is cooled by the introduced outside air. As described above, 2) “forced air cooling method” is a method of introducing outside air into the motor case, and thus water, dust, or the like may flow into the case.

JP 2004-274907 A (open type)

Accordingly, the present invention has been made in view of the above-described circumstances, and an outer rotor type brushless motor having a small number of parts, a simple structure, excellent waterproof and dustproof properties, and high cooling performance. It is to provide.

In order to solve the above problems, an outer rotor type brushless motor described in claim 1 includes a stator and a rotor, and a motor case including the stator and the rotor. Here, the stator includes a stator core having a substantially annular core body in which a plurality of teeth are integrally formed, and a plurality of coils wound around the teeth of the stator core. In addition, the rotor is formed in a substantially bottomed cylindrical shape by a cylindrical portion and a bottom portion that closes the opening of the cylindrical portion, and faces a rotor main body that is rotatably disposed surrounding the stator from one side surface side of the stator core. And a magnet provided inside the cylindrical portion of the rotor body. In the outer rotor type brushless motor, the motor case includes a case main body formed in a substantially annular shape and disposed on the outer side in the radial direction of the rotor, and a substantially annular shape formed at least partially in the diameter of the stator. And a stator mounting member that is disposed on the inner side in the direction and integrally connected to one peripheral end portion of the case main body. Further, the motor case includes the stator and the rotor in a substantially sealed state, and the core body of the stator is integrally attached to the outer wall of the stator attachment member.

  An outer rotor type brushless motor according to claim 1 includes a stator core having a substantially annular core body in which a plurality of teeth are integrally formed, and a plurality of coils wound around the teeth of the stator core. A rotor, a rotor body that is formed in a substantially bottomed cylindrical shape by a cylindrical portion and a bottom portion that closes the opening of the cylindrical portion, and that is rotatably disposed around the stator from one side surface of the stator core, and a rotor that faces the stator A rotor having a magnet provided inside a cylindrical portion of the main body, a case main body arranged radially outside the rotor, and at least a part of the case main body arranged radially inside the stator, and one peripheral edge of the case main body And a first lid member attached to the other peripheral end of the case main body, and a stator main body attached to the outer wall of the stator main body. A motor case including a case main body and a first lid member and enclosing the stator and the rotor in a substantially sealed state, a plurality of first radiating fins provided on an outer wall of the case main body, and the rotor main body And an outer rotor type brushless motor provided with a motor shaft with a rotating portion protruding outward from the motor case, the rotating portion includes an outer fan that rotates integrally with the motor shaft, The radially outer side of the outer fan and the radially outer side of one end of the first radiator fin are opposed to each other, and the outer fan blows outside air toward the radially outer side. This is an outer rotor type brushless motor.

Here, the stator is a heating element that generates heat due to the current flowing through the coil. Since the stator, which is a heating element, is integrally attached to the stator mounting member, the heat generated by the stator is effectively transmitted to the stator mounting member. Be heated. Further, since the stator mounting member is integrally connected to the case main body disposed on the radially outer side of the rotor, the heat from the stator transferred to the stator mounting member is effectively transmitted to the case main body, Effectively discharged from the main body toward the outside air. As described above, since the heat generated in the stator is effectively transferred from the stator mounting member to the case main body and is effectively released from the case main body toward the outside air, the brushless motor according to claim 1 is high. Has cooling performance.

In addition, since the brushless motor according to claim 1 adopts an air cooling method instead of a water cooling method, a pipe for supplying cooling water to the motor, a heat exchanger, and a pump for circulating the cooling water are unnecessary. The structure is simple with few parts. Furthermore, the brushless motor according to claim 1 is included in a state where the stator and the rotor are substantially sealed by the motor case, and is excellent in waterproofness and dustproofness.

Next, an outer rotor type brushless motor according to a second aspect of the present invention is the outer rotor type brushless motor according to the first aspect , wherein a plurality of heat absorbing fins integrally provided on the inner wall of the case body of the motor case are provided. It is characterized by providing. According to a second aspect of the present invention, the brushless motor includes a plurality of heat absorbing fins integrally provided on the inner wall of the case body in a motor case including the stator and the rotor. In the brushless motor according to the second aspect, the heat in the case is effectively transmitted to the case main body by the plurality of heat-absorbing fins, and has a higher cooling performance.

Next, the outer rotor type brushless motor described in claim 3 is the outer rotor type brushless motor described in claim 2 , wherein a plurality of air holes are formed in the circumferential direction at the bottom of the rotor body, It is provided with the inner fan which forms the flow of the inside air which is provided in the bottom part and penetrates a vent hole.

According to a third aspect of the present invention, the brushless motor has a vent hole formed in the bottom portion of the rotor body that is disposed to face one side surface of the stator core, and a flow of internal air that passes through the vent hole is formed in the bottom portion. An inner fan is provided. Here, since the bottom portion where the insertion hole is formed is disposed to face one side surface of the tooth around which the coil is wound, the flow of the inside air formed by the inner fan is wound around the tooth. It is introduced in the axial direction between the coils which are heat sources. The inside air introduced between the coils is introduced in the axial direction to the outside in the radial direction of the rotor, and the flow of the inside air becomes a flow circulating between the coils and the outside in the radial direction of the rotor. Due to the flow of the inside air circulating in this way, the heat of the coil, which is a heat generation source, is effectively transmitted to the case body arranged on the radially outer side of the rotor. Therefore, the brushless motor described in claim 3 has higher cooling performance.

In the brushless motor according to the fifth aspect, an outer fan that rotates together with the motor shaft is provided on the outer side of the motor case, and the outer heat is integrally formed on the outer side of the motor case by the outer fan. It is sprayed on the fin. Thus, the outside air is blown onto the first heat radiating fins, so that the heat transmitted from the stator to the motor case is effectively released to the outside of the motor. Therefore, the brushless motor described in claim 5 has higher cooling performance.

Next, an outer rotor type brushless motor according to a fourth aspect of the present invention is the brushless motor according to the third aspect , wherein the motor case is formed in a substantially disk shape and attached to the other peripheral end of the case body. A first lid member is provided, and a plurality of second radiating fins are formed on the outer wall of the first lid member. According to a sixth aspect of the present invention, the brushless motor includes a first lid member that closes the other peripheral end that is an opening of the case main body, and the outer wall of the first lid member is provided with a first lid from the case main body. A second radiating fin for effectively releasing the heat transmitted to the lid member to the outside of the motor is formed. Therefore, the brushless motor described in claim 6 has higher cooling performance.

According to the present invention, it is possible to provide an outer rotor type brushless motor having a small number of parts, a simple structure, excellent waterproofness and dustproofness, and high cooling performance.

It is a longitudinal cross-sectional view of the brushless motor in embodiment of this invention. It is a bottom view of the brushless motor seen from the viewpoint A in FIG. It is a front view of the brushless motor seen from the viewpoint B in FIG.

  Next, an outer rotor type brushless motor 1 according to an embodiment of the present invention will be described with reference to FIGS. 1, 2, and 3. Here, FIG. 1 is a longitudinal sectional view of the brushless motor 1 in the embodiment of the present invention. 2 is a bottom view of the brushless motor 1 viewed from the viewpoint A in FIG. 1, and FIG. 3 is a front view of the brushless motor 1 viewed from the viewpoint B in FIG.

  As shown in FIG. 1, the outer rotor type brushless motor 1 includes a stator 20 and a rotor 30, a motor case 10 that encloses the stator 20 and the rotor 30 in a substantially sealed state, a motor shaft 40, an inner fan 70, and an outer Fan 80 is mainly provided.

  The stator 20 includes a stator core 21, an insulator 22, and a plurality of coils 23. The stator core 21 is formed by stacking a plurality of steel plates, and has a core body 21a formed in a substantially annular shape, and a core body 21a. A plurality of teeth 21b integrally formed radially on the outer wall radially outward. The coil 23 is formed of a magnet wire W, and is wound around the teeth 21b by concentrated winding from the outside of the insulator 22 attached to both ends of the teeth 21b of the stator core 21. The coil 23 is supplied with a drive current from an external driver device (not shown) through a power line L1.

  The rotor 30 includes a rotor body 31 made of an aluminum material, a back yoke 34 formed by laminating a plurality of steel plates, and a magnet 35 in which different magnetic poles are formed in the circumferential direction.

The rotor main body 31 includes a cylindrical cylindrical portion 32 disposed on the radially outer side of the stator 20, and a disk-shaped bottom portion 33 that closes the opening of the cylindrical portion 32 and is opposed to one side surface 21 c of the stator core 21. And surrounding the stator 20 from the one side surface 21c side of the stator core 21 so as to be rotatable in the motor 1.

  The back yoke 34 is provided on the inner wall of the cylinder portion 32 of the rotor body 31, and the magnet 35 is attached to the inner wall of the bag yoke 34 inside the cylinder portion 32 of the rotor body 31 so as to face the stator 20.

  Next, the motor case 10 of the brushless motor 1 will be described. As shown in FIG. 1, the motor case 10 includes a case main body 11, a stator mounting member 12, a front cover 13 as a first lid member, and an end cover 14 as a second lid member. The stator 20 and the rotor 30 are enclosed in a substantially sealed state.

  The case body 11 and the stator attachment member 12 are integrally formed from an aluminum material. Here, the case main body 11 is formed in a substantially annular shape and disposed on the outer side in the radial direction of the rotor 30, and the stator mounting member 12 is formed in a substantially annular shape and has a cylindrical shape that is at least a part. The attachment portion 12 b is disposed on the radially inner side of the stator 20. The stator mounting member 12 has a structure integrally connected to one peripheral end portion 11c of the case main body 11, and the outer wall 12a of the mounting portion 12b of the stator mounting member 12 is provided on the core main body of the stator 20. 21a is integrally attached by the bolt S1.

As shown in FIGS. 1 and 2, a plurality of first heat radiating fins 11a are arranged in the axial direction at substantially equal intervals in the circumferential direction on the outer wall 11e in contact with the outside air in the case body 11 as an air cooling structure. It is integrally formed in the state. A plurality of heat-absorbing fins 11b are integrally formed on the inner wall 11f in contact with the inside air in the case body 11 in a state where the heat-absorbing fins 11b are arranged in the axial direction at substantially equal intervals in the circumferential direction. An end cover 14 is integrally attached to one peripheral end portion 11 c of the case body 11 from the outside of the case body 11.

  As shown in FIGS. 1 and 3, a substantially disc-shaped front cover 13 is integrally attached to the other peripheral end portion 11d, which is an opening of the case body 11, from the outside of the case body 11 by screws S2. ing. The opening formed by the other peripheral end portion 11 d of the case body 11 is closed by the front cover 13. A plurality of second radiating fins 13a are integrally formed in the radial direction on the outer wall 13b of the front cover 13 that comes into contact with the outside air.

  Next, the motor shaft 40 provided in the brushless motor 1 will be described with reference to FIG. The motor shaft 40 is formed in a substantially rod shape and is rotatably supported by a bearing B1 provided on the front cover 13 and a bearing B2 provided on the stator mounting member 12. Here, the output portion 41 that is one end portion of the motor shaft 40 protrudes toward the outside of the motor 1 from the front cover 13 side, and the rotating portion 42 that is the other end portion of the motor shaft 40 is the stator mounting member 12. Projecting outward from the motor 1. A disc-shaped flange 43 formed integrally with the motor shaft 40 is attached to the rotor body 31 with screws S3.

  As shown in FIG. 1, in the space formed by the stator attachment member 12 and the end cover 14, a rotation member 50 to which a ring magnet 51 is attached, and a rotation detection substrate 60 having a rotation detection element 61 are provided. , Is provided. The rotating member 50 is integrally attached to the rotating portion 42 of the motor shaft 40, and the rotation detecting element 61 is disposed at a position facing the ring magnet 51. The ring magnet 51 is formed with different magnetic poles alternately in the circumferential direction. The rotation information of the motor shaft 40 detected by the rotation detection element 61 is transmitted from the rotation detection substrate 60 to the external driver device (by the sensor line L2). (Not shown)

  Here, as shown in FIG. 1, the gap between the rotary member 50 and the end cover 14 that covers the rotary member 50 and the rotation detection substrate 60 has a labyrinth seal structure LS. By this labyrinth seal structure LS, the rotary member 50 and the rotation detection substrate 60 are kept waterproof and dustproof.

  Finally, the inner fan 70 and the outer fan 80 provided in the brushless motor 1 will be described in order based on FIG. 1 and FIG. As shown in FIG. 1, a plurality of ventilation holes 33 a are formed in the circumferential direction in the bottom 33 of the rotor body 31. And the inner fan 70 which forms the flow of the inside air which penetrates this ventilation hole 33a is attached to the upper surface of the bottom part 33 integrally. Further, an outer fan 80 is integrally attached to the fan attachment portion 46 in the rotating portion 42 of the motor shaft 40 by a nut N. Then, the outer fan 80 blows outside air to the first radiating fins 11 a formed on the case body 11.

The present invention is not limited to the above-described embodiment, and includes various modifications made to the above-described embodiment without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 Outer rotor type brushless motor 10 Motor case 11 Case main body 11a 1st radiation fin 11b Heat absorption fin 11c One peripheral edge part 11d The other peripheral edge part 11e Outer wall 11f Inner wall 12 Stator attachment member 12a Outer wall 12b A part (attachment part)
13 First lid member (front cover)
13a 2nd radiation fin 13b outer wall 14 2nd cover member (end cover)
20 Stator 21 Stator Core 21a Core Main Body 21b Teeth 21c One Side 22 Insulator 23 Coil 30 Rotor 31 Rotor Main Body 32 Tube 33 Bottom 33a Vent 34 Back Yoke 35 Magnet 40 Motor Shaft 41 Output 42 Rotation 43 Flange 44 Bearing 45 Bearing portion 46 Fan mounting portion 50 Rotating member 51 Ring magnet 60 Rotation detection substrate 61 Rotation detection element 70 Inner fan 80 Outer fan S1 Bolt S2 Screw S3 Screw N Nut L1 Power line L2 Sensor line B1 Bearing B2 Bearing LS Labyrinth seal W Magnet Wire

Claims (4)

A stator core having a substantially annular core body in which a plurality of teeth are integrally formed, a stator having a plurality of coils wound around the teeth of the stator core, and the cylindrical portion and the opening of the cylindrical portion are closed. A rotor body that is formed in a substantially bottomed cylindrical shape by a bottom portion and is rotatably disposed surrounding the stator from one side surface of the stator core, and is provided inside the cylinder portion of the rotor body so as to face the stator. A rotor having a magnet formed therein, a case main body disposed on the radially outer side of the rotor, and at least a part thereof is disposed on the radial inner side of the stator, and is connected to one peripheral end of the case main body, A stator attachment member to which the core body of the stator is attached to an outer wall; a first lid member attached to the other peripheral end of the case body; A motor case including the stator body and the first lid member, and including the stator and the rotor in a substantially sealed state, a plurality of first radiating fins provided on an outer wall of the case body, In an outer rotor type brushless motor comprising a motor shaft connected to the rotor body and having a rotating portion protruding outward from the motor case ,
The rotating portion includes an outer fan that rotates integrally with the motor shaft, and the outer fan is provided on a radially inner side of the first radiating fin, and a radially outer side of the outer fan and the first radiating heat. An outer rotor type brushless motor characterized in that a radially inner end of one end in the axial direction of the fin faces and the outer fan blows outside air toward a radially outer side . In the outer rotor type brushless motor according to claim 1 ,
An outer rotor type brushless motor comprising a plurality of heat absorbing fins integrally provided on an inner wall of a case body of the motor case. In the outer rotor type brushless motor according to claim 2 ,
A plurality of air holes are formed in the bottom portion of the rotor body in the circumferential direction, and an outer rotor type brushless provided with an inner fan provided in the bottom portion and forming a flow of internal air passing through the air holes. motor. In the outer rotor type brushless motor according to claim 3 ,
An outer rotor type brushless motor, wherein a plurality of second heat radiation fins are formed on the outer wall of the first lid member.

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