Outer rotor type electric motor with transmission

Abstract

The present invention provides an outer rotor type motor with a transmission part, which can suppress the processing cost of motor parts, reduce the number of parts, reduce the assembly process, and maintain the load resistance and life of external loads. The rotor hub (8) has an inner cylindrical part (8a) extending axially on the inner surface side of the rotor yoke (6) and an outer cylindrical part (8b) extending axially on the outer surface side of the rotor yoke (6), and a motor gear (8c) is integrally formed on a part of the outer cylindrical part (8b). A fixed shaft (3) is inserted into the cylindrical hole (8d) of the rotor hub (8) and a rotor unit (5) is assembled on the stator unit (1) in a manner that the rotor magnet (7) and the pole teeth (2b) are opposite to each other.

Description

Technical Field

[0001] The present invention relates to an outer rotor type electric motor with a transmission part used as a driving source of an electric motor such as a damper actuator for a high-rise air conditioner. Background Art

[0002] In an outer rotor type DC brushless motor, a metal mounting plate is supported by a metal bearing housing such as brass, and a base plate is integrally assembled to the metal mounting plate. An oil-retaining bearing is assembled in the bearing housing, and a rotor shaft is rotatably supported by the oil-retaining bearing.

[0003] One end of the rotor shaft is integrally connected to the rotor hub that holds the rotor yoke. The rotor hub is made of a metal component such as brass and is riveted to the cup-shaped rotor yoke to be integrally assembled. In addition, a metal motor gear is press-fitted into the other end (output end) of the rotor shaft.

[0004] The stator is integrally assembled to the bearing housing. Specifically, the annular core back of the stator core is pressed and bonded to the outer periphery of the bearing housing and assembled. In addition, the coil is wound around the pole teeth extending radially outward from the core back via an insulator. The tooth tops of the pole teeth, i.e., the flux action surfaces, are assembled in a manner opposite to the annular rotor magnets provided on the inner periphery of the rotor yoke. The blowers (air blowers) used in the past hoped to be miniaturized on the one hand, and on the other hand, to improve the required performance and achieve high pressure, high flow, and high responsiveness. Therefore, the direction of reducing the diameter of the impeller and rotating at a faster speed has been turned.

[0005] The stator-side structural components of the outer rotor type motor, i.e., the bearing housing and the bearing, are made of metal parts, and the rotor-side structural components rotatably supported by the bearing, i.e., the rotor shaft, the rotor yoke, etc., are also made of metal parts, and the rotor hub and the rotor shaft are integrally assembled by press-fitting or the like (see Patent Document 1: Japanese Patent Laid-Open No. 2001-298893, Patent Document 2: Japanese Patent Laid-Open No. 2014-18068)

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Publication No. 2001-298893

[0009] Patent Document 2: Japanese Patent Application Publication No. 2014-18068

[0010] However, in order to maintain the perpendicularity of the rotor shaft and the load-bearing performance, the above-mentioned motor uses metal parts such as oil-retaining bearings, bearing housings, mounting plates, and motor gears, which increases the production cost (parts cost).

[0011] Therefore, in order to reduce production costs, it is considered to reduce component costs as much as possible by making motor components of resin. In this case, there are the following concerns when making motor components of resin.

[0012] (1) When the motor gear is made of resin, it may not be possible to ensure sufficient shaft fastening force with the rotor shaft. It is also conceivable to apply knurling or D-cutting to the rotor shaft, but this will increase the processing cost.

[0013] (2) When the oil-containing bearing or the bearing housing is made of resin, the load resistance performance and life of the bearing against external load may be reduced. Summary of the invention

[0014] The present invention is made to solve the above-mentioned technical problems, and its purpose is to provide an outer rotor type motor with a belt transmission part, which can suppress the processing cost of motor components and reduce the number of components and assembly steps, and can maintain the load resistance performance and life of external loads.

[0015] In order to solve the above technical problems, the present invention at least includes the following structures.

[0016] The transmission part is provided on the output shaft of the rotor, comprising: a stator unit having a stator core and an insulator, the stator core having a plurality of pole teeth protruding radially outward from a core back portion formed in an annular shape, the insulator being integrally formed with a fixed shaft inserted into a center hole of the core back portion through a first resin component covering the stator core; and a rotor unit having an annular rotor magnet on the inner peripheral surface of a rotor yoke formed in a cup shape, and a motor gear being integrally formed on the outer surface of a rotor hub formed by at least a second resin component, the fixed shaft being inserted into the cylindrical hole of the rotor hub and the stator unit and the rotor unit being assembled in a manner that the rotor magnet and the pole teeth are opposite to each other, the rotor unit being assembled to be able to slide and rotate around the fixed shaft.

[0017] According to the above structure, by making the motor structural parts that are usually made of metal products such as the rotor yoke, bearing, bearing housing, mounting plate, motor gear, etc. resin, the number of parts can be reduced as much as possible and the manufacturing cost can be reduced.

[0018] In addition, since at least the rotor hub in the rotor unit is composed of a second resin component such as engineering plastic, a transmission part (motor gear, connecting part, etc.) is integrally molded on the outer surface of the rotor hub. Therefore, the axial tightening force of the transmission part and the rotor hub replacing the rotor shaft can be fully ensured, and since knurling and D-shaped cutting are not required, the processing cost can be reduced.

[0019] Furthermore, by making the axial load support distance from the transmission part provided on the outer surface side of the rotor hub to the cylindrical hole of the rotor hub longer than before, the load resistance performance and life of the motor against external load can be maintained.

[0020] Preferably, the insulator covers at least the core back and the periphery of the pole teeth, and the center hole of the core back is closed by the insulator connected to the fixed shaft.

[0021] Therefore, since the core back and the surrounding area of ​​the pole teeth are covered with insulators, there is no need to assemble the insulator to the stator core later. Moreover, since the center hole of the core back is closed by the insulator, there is no need to assemble the stator core to the bearing retaining part as in the past. This reduces the number of parts and improves assemblability.

[0022] In the rotor unit, the rotor yoke formed in a cup shape and the rotor hub formed of a resin member may be integrally molded.

[0023] This eliminates the need for assembling the rotating shaft to the rotor yoke, thereby reducing the number of components and improving assemblability.

[0024] The rotor hub comprises an inner cylindrical portion extending axially on the inner surface side of the rotor and an outer cylindrical portion extending axially on the outer surface side of the rotor, a motor gear is integrally formed at the end of the outer cylindrical portion, and the rotor unit is assembled by inserting the inner cylindrical portion of the rotor hub into the center hole of the core back portion.

[0025] Alternatively, the rotor hub may include an inner cylindrical portion extending axially on the inner surface side of the rotor and an outer cylindrical portion extending axially on the outer surface side of the rotor, a motor gear being integrally formed at the end of the outer cylindrical portion, and the rotor unit being assembled by inserting the inner cylindrical portion of the rotor hub into the center hole of the core back portion.

[0026] Thus, the load fulcrum distance from the transmission part (motor gear or coupling part) can be extended by extending the axial length of the inner cylindrical part of the rotor hub, and the axial load fulcrum distance from the inner cylindrical part of the rotor hub to the transmission part can be extended by providing the motor gear and the coupling part at the end of the outer cylindrical part of the rotor hub. Therefore, the load resistance performance and life of the motor against external load can be maintained.

[0027] An outer rotor type motor with a transmission part can be provided, which can suppress the processing cost of motor parts, reduce the number of parts, reduce the number of assembly steps, and maintain the load resistance performance and life of the motor with respect to external loads. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a three-dimensional diagram of the stator unit.

[0029] Figure 2 It is a three-dimensional diagram of the rotor unit.

[0030] Figure 3 This is a perspective view of an outer rotor type motor with gears.

[0031] Figure 4 yes Figure 3 An axial cross-sectional view of an outer rotor type motor with a gear.

[0032] Figure 5 This is a perspective view of another example of a rotor unit.

[0033] Figure 6 This is a perspective view of another example of a rotor unit.

[0034] Figure 7 This is a perspective view of another example of a rotor unit. DETAILED DESCRIPTION

[0035] Hereinafter, an example of an outer rotor type motor with a transmission part will be described with reference to the accompanying drawings. The description will be made using an outer rotor type motor with a gear as an example of a transmission part. The outer rotor type motor with a gear is a motor in which a rotor is rotatably assembled on the radial outer side of a stator and a gear is provided on the output shaft of the rotor.

[0036] exist Figure 1 In the embodiment, the stator unit 1 includes a stator core 2 having pole teeth 2b protruding radially outward from a core back 2a formed in an annular shape. A fixed shaft 3 is inserted into a center hole 2c of the core back 2a of the stator core 2, and the stator unit 1 is formed by insert molding of a first resin member (insulating resin member, such as PBT: polybutylene terephthalate resin, etc.). Specifically, the core back 2a and the pole teeth 2b are covered by an insulator 4, and the fixed shaft 3 is integrally molded with the insulator 4. The fixed shaft 3 becomes the rotation center of the rotor unit as described later, thereby realizing the fixed axis of the rotor shaft.

[0037] like Figure 4 As shown, the center hole 2c of the core back portion 2a at one axial end side of the stator core 2 is closed by the insulator 4 connected to the fixed shaft 3. In this way, since the center hole 2c of the core back portion 2a is closed by the insulator 4 by insert molding the stator core 2 and the fixed shaft 3, it is not necessary to assemble the stator core 2 to the bearing holding portion as in the past, and since the core back portion 2a and the periphery of the pole teeth 2b are covered by the insulator 4, it is not necessary to assemble the insulator 4 to the stator core 2 later, which reduces the number of parts and improves the assemblability.

[0038] Furthermore, the stator core 2 and the fixed shaft 3 are insert-molded together with an insulating resin member and are integrally assembled by being covered with an insulator 4. Therefore, the axial right angle of the fixed shaft 3 and the stator core 2 integrated by insert molding is maintained. The magnetic wire 2d is wound around the pole teeth 2b of the stator core 2 covered with the insulator 4, and the stator unit 1 is assembled.

[0039] In addition, if Figure 1 As shown, the end of the insulator 4 on the opposite side of the output of each pole tooth 2b of the stator core 2 is inserted into the insertion hole of the substrate (not shown), and the substrate insertion pieces 4a whose front ends are welded are arranged at multiple locations (at least three locations) at equal angles. Each substrate insertion piece 4a is formed with a step portion 4b that abuts against the substrate and a welding portion 4c that is inserted into the substrate insertion hole (not shown) and extends to the opposite side of the substrate for welding. In addition, instead of the welding portion 4c, a snap-fit, bolt fastening, or adhesive fixation may be used.

[0040] Next, refer to Figure 2 and Figure 4 The structure of the rotor unit 5 is described. Figure 2 As shown, the rotor yoke 6 is formed of a magnetic metal member formed into a cup shape and has a through hole 6a (see Figure 4 ) An annular rotor magnet 7 is provided on the inner peripheral surface of the rotor yoke 6. The rotor magnet 7 is magnetized so that N poles and S poles are alternately formed in the circumferential direction.

[0041] In addition, if Figure 4 As shown, a through hole 6a is formed in the center of the rotor yoke 6, and a magnetic metal member with a reduced metal portion as much as possible is insert-molded using a second resin member having good wear resistance and sliding properties, such as an engineering plastic resin member (POM: polyacetal resin, etc.), thereby integrally molding a rotor hub 8 including a motor gear 8c described later. The rotor hub 8 extends axially on the inner and outer surface sides of the rotor yoke 6 through the through hole 6a.

[0042] like Figure 4 As shown, the rotor hub 8 is integrally formed in a cylindrical shape at the center of the rotor yoke 6, and has an inner cylindrical portion 8a extending axially on the inner surface side of the rotor yoke 6 and an outer cylindrical portion 8b extending axially on the outer surface side of the rotor yoke 6. A motor gear 8c is integrally formed at the cylindrical end of the outer cylindrical portion 8b.

[0043] In addition, the motor gear 8c does not necessarily have to be provided at the end of the outer cylindrical portion 8b. Figure 5 As shown, a part of the outer cylindrical portion 8 b on the axially outer surface side of the rotor yoke 6 is integrally formed with the rotor hub 8 .

[0044] In the rotor unit 5, as long as at least the rotor hub 8 integrally formed with the motor gear 8c is a resin member, it may be Figure 6 As shown, the cup-shaped rotor yoke 6 is integrally molded from, for example, an engineering plastic resin member. In this case, the annular rotor magnet 7 is insert-molded on the inner peripheral surface of the cup-shaped rotor yoke 6 and integrally assembled.

[0045] like Figure 3 As shown, the fixed shaft 3 is inserted into the cylindrical hole 8d of the cylindrical rotor hub 8, and the stator unit 1 and the rotor unit 5 are assembled in such a manner that the rotor magnet 7 and the pole teeth 2b are opposite to each other, and the rotor unit 5 is assembled so as to be able to slide and rotate around the fixed shaft 3. Specifically, the inner cylindrical portion 8a of the rotor hub 8 is inserted into the center hole 2c on the other axial end side of the core back portion 2a, and the end of the cylinder is abutted against the insulator 4, so that the rotor unit 5 is assembled to the stator unit 1.

[0046] Thus, the axial load support distance D from the motor gear 8c can be extended by extending the axial length of the inner cylindrical portion 8a of the rotor hub 8 (see Figure 4 ), the axial load fulcrum distance D from the inner cylindrical portion 8a of the rotor hub 8 to the motor gear 8c can be extended by providing a motor gear 8c at the end of the outer cylindrical portion 8b of the rotor hub 8 (refer to Figure 4 ). Therefore, the load resistance performance and life of the motor to the external load can be maintained.

[0047] Although the rotor unit 5 is integrally formed with a motor gear 8c as a transmission part at the end of the outer cylindrical portion 8b of the rotor hub 8, the present invention is not limited thereto. Figure 7 As shown in the figure, a connecting portion 8e is formed on a part of the outer cylindrical portion 8b. Specifically, a connecting portion 8e in the shape of a regular hexagonal column is formed on the outer cylindrical portion 8b. The drive is transmitted by fitting the connecting portion 8e with a connecting portion having a hexagonal hole not shown in the figure. In addition, although the connecting portion 8e is formed in the middle of the outer cylindrical portion, it can also be formed at the end of the cylinder.

[0048] In summary, by making the motor structural parts that are usually made of metal products such as the rotor yoke, bearings, bearing housings, mounting plates, and motor gears into resin, the number of parts can be reduced as much as possible and the manufacturing cost can be reduced.

[0049] In addition, since at least the rotor hub 8 in the rotor unit 5 is composed of a resin component such as engineering plastic, a transmission part (motor gear 8c, connecting part 8e, etc.) is integrally molded on the outer surface of the rotor hub 8. Therefore, the axial tightening force between the motor gear 8c and the rotor hub 8 replacing the rotor shaft can be fully ensured, and since knurling and D-shaped cutting are not required, the processing cost can be reduced.

[0050] Furthermore, by making the axial load support distance from the motor gear 8c provided on the outer surface side of the rotor hub 8 to the cylindrical hole of the rotor hub 8 longer than before, the load resistance performance and life of the motor against external load can be maintained.

[0051] Furthermore, by insert-molding the rotor unit 5 and the stator unit 1 using an optimum resin, it is possible to reduce the number of structural parts and provide an outer rotor type motor with a transmission part having good assemblability at a low cost.

Claims

1. An outer rotor type electric motor with a transmission part, wherein the rotor of the outer rotor type electric motor with a transmission part is rotatably assembled on the radially outer side of the stator, and the transmission part is provided on the rotor, characterized in that: include: a stator unit including a stator core having a plurality of pole teeth projecting radially outward from a core back portion formed in an annular shape, and an insulator having a fixed shaft integrally formed with a first resin member covering the stator core and inserted into a center hole of the core back portion; and A rotor unit having an annular rotor magnet on the inner peripheral surface of a rotor yoke formed in a cup shape, and having a motor gear portion integrally molded on the outer surface of a rotor hub formed of at least a second resin member, The rotor hub includes an inner cylindrical portion extending axially on the inner surface side of the rotor yoke and an outer cylindrical portion extending axially on the outer surface side of the rotor yoke, the motor gear portion is formed on the outer cylindrical portion, and the inner cylindrical portion of the rotor hub of the rotor unit is inserted into the center hole of the core back portion. The fixed shaft is inserted into the cylindrical hole of the rotor hub, and the stator unit and the rotor unit are assembled so that the rotor magnet and the pole teeth face each other. The rotor unit is assembled so as to be slidable and rotatable around the fixed shaft.

2. An outer rotor type electric motor with a transmission part, wherein the rotor of the outer rotor type electric motor with a transmission part is rotatably assembled on the radially outer side of the stator, and the transmission part is provided on the rotor, characterized in that: include: a stator unit including a stator core having a plurality of pole teeth projecting radially outward from a core back portion formed in an annular shape, and an insulator having a fixed shaft integrally formed with a first resin member covering the stator core and inserted into a center hole of the core back portion; and A rotor unit, wherein an annular rotor magnet is provided on the inner peripheral surface of a rotor yoke formed in a cup shape, and a coupling portion is integrally formed on the outer surface of a rotor hub composed of at least a second resin member, The rotor hub comprises an inner cylindrical portion extending axially on the inner surface side of the rotor yoke and an outer cylindrical portion extending axially on the outer surface side of the rotor yoke, the coupling portion being formed on the outer cylindrical portion, and the inner cylindrical portion of the rotor hub of the rotor unit is inserted into the center hole of the core back portion. The fixed shaft is inserted into the cylindrical hole of the rotor hub, and the stator unit and the rotor unit are assembled so that the rotor magnet and the pole teeth face each other. The rotor unit is assembled so as to be slidable and rotatable around the fixed shaft.

3. The outer rotor type motor with a belt transmission according to claim 1 or 2, characterized in that: The insulator covers at least the core back and the periphery of the pole teeth, and the center hole of the core back is closed by the insulator connected to the fixed shaft.

4. The outer rotor type motor with a belt transmission according to claim 1 or 2, characterized in that: In the rotor unit, a rotor yoke formed in a cup shape and a rotor hub formed of a second resin member are integrally molded.

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