Outer rotor motor

Abstract

The present invention provides an outer rotor type electric motor, which can suppress the processing cost of electric motor components, reduce the number of components, and reduce the number of assembly steps, and can maintain the performance of the electric motor without reducing the axial perpendicularity between the stator core and the rotor shaft, and the axial perpendicularity between the stator core and the motor substrate. The stator core (2) and the fixed shaft (3) inserted into the center hole (2c) of the core back (2a) are integrally molded together with an insulator (4) using an insulating resin member, and a plurality of substrate insertion pieces (4a) protruding from the axial output opposite end side of the insulator (4) are engaged with the substrate insertion holes (9a), so that the stator core (2) and the substrate (9) are integrally assembled.

Description

Technical Field

[0001] The present invention relates to an outer rotor type electric motor 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 within the bearing housing, and the rotor shaft is rotatably supported by the oil-retaining bearing.

[0003] One end of the rotor shaft is integrally connected to the rotor hub, which holds the rotor yoke. The rotor hub is riveted to the cup-shaped rotor yoke, using a metal component such as brass. Furthermore, a metal motor gear is press-fitted into the other end of the rotor shaft (the output end).

[0004] The stator is integrally assembled to the bearing housing. Specifically, the annular core back of the stator core is press-fitted and bonded to the outer periphery of the bearing housing. Furthermore, the coil is wound around the pole teeth extending radially outward from the core back through an insulator.

[0005] The tooth tips of the pole teeth, ie, the magnetic flux action surfaces, are assembled so as to face the annular rotor magnet provided on the inner periphery of the rotor yoke.

[0006] In order to maintain the perpendicularity of the rotor shaft, the stator core of the above-mentioned motor is fixed to a relatively rigid member such as a metal motor housing or a bearing housing.

[0007] In addition, the coil leads drawn from the coils wound around the stator teeth are connected to the circuit substrate to control the power supply, or a sensor substrate such as a Hall IC is provided, and the circuit substrate, the sensor substrate and the control substrate of the upper device are electrically connected through external connection terminals.

[0008] In outer rotor motors, the stator-side components, namely the bearing housing and bearings, are made of metal. The rotor-side components, such as the rotor shaft and rotor yoke, which are rotatably supported by the bearings, are also made of metal. The rotor hub and rotor shaft are integrally assembled by press-fitting or the like (see Patent Document 1: Japanese Patent Application Publication No. 2001-298893, Patent Document 2: Japanese Patent Application Publication No. 2014-18068).

[0009] Prior art literature

[0010] Patent Literature

[0011] Patent Document 1: Japanese Patent Application Laid-Open No. 2001-298893

[0012] Patent Document 2: Japanese Patent Application Laid-Open No. 2014-18068

[0013] However, the above-mentioned motor requires wiring connections to multiple substrates such as the circuit substrate on the motor side and the control substrate on the equipment side, which increases the number of components such as the bearing housing and motor housing that fix the stator core, thereby increasing manufacturing costs.

[0014] Therefore, to reduce production costs, one approach is to integrate the rotor shaft and stator core through insert molding and mount the stator core on a unified circuit board, thereby reducing the number of components and lowering costs. However, this approach presents the following concerns when molding motor components into resin.

[0015] (1) The perpendicularity between the stator core and the rotor shaft may be reduced, thereby reducing the performance of the motor.

[0016] (2) The perpendicularity between the stator core and the base plate may be reduced, thereby reducing the performance of the motor. Summary of the Invention

[0017] The present invention is made to solve the above-mentioned technical problems, and its purpose is to provide an outer rotor type electric motor that can suppress the processing cost of motor components and reduce the number of components and assembly steps, and maintain the motor performance without reducing the axial perpendicularity between the stator core and the rotor shaft, and the axial perpendicularity between the stator core and the substrate.

[0018] In order to solve the above technical problems, the present invention at least includes the following structures.

[0019] An outer rotor type electric motor, wherein the rotor of the outer rotor type electric motor is rotatably assembled on the radially outer side of the stator, comprising: a stator unit, the stator unit having a stator core, an insulator, and a base plate, the stator core having a plurality of pole teeth projecting 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 member covering the stator core, the base plate being assembled with the stator core via the insulator and being electrically connected to a magnetic wire wound around the pole teeth via the insulator; and a rotor unit The rotor unit is provided with an annular rotor magnet on the inner peripheral surface of a rotor yoke formed in a cup shape, and is integrally formed with a rotor hub composed of at least a second resin member, a plurality of substrate insertion pieces protruding from the axially opposite output end side of the above-mentioned insulator are engaged with the substrate insertion holes, so that the stator core and the above-mentioned substrate are assembled as a whole, the above-mentioned fixed shaft is inserted into the cylindrical hole of the above-mentioned rotor hub, and the above-mentioned stator unit and the above-mentioned rotor unit are assembled in such a manner that the above-mentioned rotor magnet and the above-mentioned pole teeth are opposed to each other, and the above-mentioned rotor unit is assembled so as to be able to slide and rotate around the above-mentioned fixed shaft.

[0020] According to the above structure, by making the motor components that are usually made of metal, such as the bearing, bearing housing, mounting plate, and motor gear, resin, the number of components can be reduced as much as possible and the manufacturing cost can be reduced.

[0021] Furthermore, by integrally molding the fixed shaft inserted into the center hole of the core back with the first resin member covering the stator core, i.e., the insulator, the motor performance can be maintained without reducing the axial perpendicularity between the stator core and the fixed shaft to which the rotor unit is assembled.

[0022] The stator core and the substrate are integrally assembled by fitting a plurality of substrate insertion pieces protruding from the axially opposite output end of the insulator into the substrate insertion holes, thereby maintaining motor performance without reducing the axial perpendicularity between the stator core and the substrate.

[0023] The substrate insertion piece may include a step portion inserted into the substrate insertion hole of the substrate and abutting against an insertion surface, and a substrate fixing portion having a front end extending to the opposite surface and fixed thereto.

[0024] By inserting the multiple substrate insertion pieces of the insulator into the substrate insertion holes and placing the stepped portions against the insertion surfaces, the stator core is positioned at the same height relative to the substrate. The stator core and substrate are then positioned and assembled by securing the front ends on the opposite sides. This maintains the axial perpendicularity between the stator core and substrate, improving assembly efficiency.

[0025] The insulator may include substrate insertion pieces provided corresponding to the pole teeth of the stator core, and support legs provided between the substrate insertion pieces corresponding to the pole teeth to abut against and support the substrate.

[0026] Therefore, since substrate insertion pieces are provided corresponding to the pole teeth of the stator core, the stator core can be assembled parallel to the substrate in a manner maintaining the axial right angle. When support legs that abut against the substrate for support are provided between the substrate insertion pieces corresponding to the pole teeth, the assembly posture of the stator core to the substrate can be stabilized.

[0027] An outer rotor type motor can be provided, which can suppress the processing cost of motor components and reduce the number of components and assembly steps, and can maintain the motor performance without reducing the axial perpendicularity between the stator core and the rotor shaft assembled with the rotor unit, and the axial perpendicularity between the stator core and the substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a perspective view of the stator unit.

[0029] Figure 2 This is a perspective view of the rotor unit.

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

[0031] Figure 4 yes Figure 3 Axial cross-sectional view of a rotor-type motor.

[0032] Figure 5 These are a front view, a right side view, and a perspective view showing the assembled state of the stator unit and the base plate.

[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] An example of an outer rotor type motor will be described below with reference to the drawings. An outer rotor type motor is a motor in which a rotor is rotatably mounted radially outside a stator and a gear is provided on an 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 projecting radially outward from an annular core back 2a. A fixed shaft 3 is inserted into the center hole 2c of the core back 2a of the stator core 2, and the stator unit 1 is formed by insert molding a first resin member (an insulating resin member, such as PBT (polybutylene terephthalate) resin). Specifically, the core back 2a and the pole teeth 2b are covered with an insulator 4, and the fixed shaft 3 and the insulator 4 are integrated. As described later, the fixed shaft 3 serves as the rotation center of the rotor unit 5, thereby achieving a fixed rotor shaft.

[0037] like Figure 4 As shown, the center hole 2c of the core back portion 2a at one axial end of the stator core 2 is sealed by an insulator 4 connected to the fixed shaft 3. Thus, since the stator core 2 and the fixed shaft 3 are insert-molded, the center hole 2c of the core back portion 2a is sealed by the insulator 4. This eliminates the need for conventional assembly steps such as assembling the stator core 2 to a bearing holder. Furthermore, since the core back portion 2a and the pole teeth 2b are covered by the insulator 4, the subsequent assembly of the insulator 4 to the stator core 2 is also unnecessary. This reduces the number of components and improves assembly efficiency.

[0038] Furthermore, the stator core 2 and the fixed shaft 3 are insert-molded together using an insulating resin member and assembled integrally while covered by the insulator 4. Consequently, the axial perpendicularity between the fixed shaft 3 and the stator core 2, which are integrated by insert molding, is maintained. Magnetic wire 2d is wound around the pole teeth 2b of the stator core 2, which is covered by the insulator 4, to complete the stator unit 1. In this way, the stator core 2 and the fixed shaft 3, inserted into the center hole 2c of the core back 2a, are integrally molded using an insulating resin member and the insulator 4. This maintains motor performance without compromising the axial perpendicularity between the stator core 2 and the fixed shaft 3, to which the rotor unit 5 is assembled.

[0039] In addition, if Figure 1 As shown, the end portion on the opposite side of the output of the insulator 4 covering each pole tooth 2b of the stator core 2 is inserted into the substrate insertion hole 9a of the substrate 9 (see Figure 5 (b) Figure 5 (c)), the substrate insertion pieces 4a with the front ends welded are arranged at multiple locations (at least three locations) at equal angles. Each substrate insertion piece 4a has a step portion 4b that abuts against the substrate 9 and a welding portion 4c (substrate fixing portion) that is inserted into the substrate insertion hole 9a and extends to the opposite side of the substrate 9 and is welded. The magnetic wire 2d wound around the pole teeth 2b of the stator core 2 via the insulator 4 is connected to the substrate 9 described later (see Figure 5 )'s substrate terminals are electrically connected.

[0040] In this way, the multiple substrate insertion pieces 4a protruding from the axially opposite output end of the insulator 4 are engaged with the substrate insertion holes 9a, allowing the stator core 2 and substrate 9 to be integrally assembled. This maintains motor performance without compromising the axial perpendicularity between the stator core 2 and substrate 9. Furthermore, by inserting the multiple substrate insertion pieces 4a of the insulator 4 into the substrate insertion holes 9a and abutting the stepped portion 4b against the insertion surface, the stator core 2 is positioned at the same height relative to the substrate 9. By welding the welded portion 4c at the front end to the opposite surface, the stator core 2 and substrate 9 are positioned and assembled. Furthermore, the substrate securing portion is not limited to the welded portion 4c; other structures are also possible, such as snap-fitting, bolted fastening, or adhesive fastening. Furthermore, the substrate insertion pieces 4a provided at multiple locations on the insulator 4 do not need to be arranged at equal angles.

[0041] like Figure 5 (a)~ Figure 5 As shown in (c), the welding portion 4c is extended to the surface of the substrate 9 opposite to the motor mounting surface, and the front end of the welding portion 4c protruding from the substrate 9 is welded. For example, in the case of a stator core 2 with nine slots, the substrate insertion pieces 4a are provided at least at three locations, and the remaining six locations are provided with support legs 4d that abut against the substrate surface for support (see Figure 1、 Figure 4 ) In addition, substrate insertion pieces 4 a may be provided corresponding to all the pole teeth 2 b of the insulator 4 covering the stator core 2 .

[0042] Therefore, since the substrate insertion pieces 4a are arranged at equal intervals corresponding to the pole teeth 2b of the stator core 2, the stator core 2 can be assembled parallel to the substrate 9 in a manner maintaining the axial right angle. When the support legs 4d that abut against the substrate 9 for support are provided between the substrate insertion pieces 4a corresponding to the pole teeth 2b, the assembly posture of the stator core 2 on the substrate 9 can be stabilized.

[0043] Next, refer to Figure 2 and Figure 4 The structure of the rotor unit 5 will be described. Figure 2 As shown, the rotor yoke 6 is made of a magnetic material and is formed into a cup shape, and a through hole 6a is formed with a hollowed-out center portion (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.

[0044] In addition, if Figure 4 As shown, a through-hole 6a is formed in the center of the rotor yoke 6. A cup-shaped magnetic metal member with minimal metal content is insert-molded using a second resin member with excellent wear resistance and sliding properties, such as an engineering plastic resin member (POM: polyacetal resin), thereby integrally forming a rotor hub 8 including a motor gear 8c, described later. The rotor hub 8 extends axially integrally on the inner and outer surfaces of the rotor yoke 6 through the through-hole 6a.

[0045] 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 includes an inner cylindrical portion 8a extending axially on the inner surface of the rotor yoke 6 and an outer cylindrical portion 8b extending axially on the outer surface of the rotor yoke 6. A motor gear 8c is integrally formed at the end of the outer cylindrical portion 8b. The motor gear 8c does not necessarily have to be provided at the end of the outer cylindrical portion 8b, and may also be provided at the outer cylindrical portion 8b, for example. Figure 6 As shown, a portion 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 .

[0046] 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 7 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 circumference of the cup-shaped rotor yoke 6 and integrally assembled.

[0047] like Figure 3 As shown, the fixed shaft 3 is inserted into the cylindrical hole 8d of the cylindrical rotor hub 8, and the rotor unit 5 is assembled to the stator unit 1 so that the rotor magnet 7 and the pole teeth 2b face each other. The rotor unit 5 is assembled so as to be slidable and rotatable about 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 of the core back portion 2a, and the cylindrical end is brought into contact with the insulator 4, thereby assembling the rotor unit 5 to the stator unit 1.

[0048] 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 support distance D between the inner cylindrical portion 8a of the rotor hub 8 and 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-bearing performance and life of the motor against external loads can be maintained.

[0049] In summary, by making the motor structural components that are usually made of metal products such as 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.

[0050] In addition, the stator core 2 and the fixed shaft 3 inserted into the center hole 2c of the core back 2a are integrally molded with the insulator 4 using an insulating resin component, thereby maintaining the motor performance without reducing the axial perpendicularity between the stator core 2 and the fixed shaft 3 assembled with the rotor unit 5.

[0051] The plurality of substrate insertion pieces 4a protruding from the axially opposite output end of the insulator 4 are fitted into the substrate insertion holes 9a, and the stator core 2 and the substrate 9 are integrally assembled, thereby maintaining the motor performance without reducing the axial perpendicularity between the stator core 2 and the substrate 9.

[0052] Furthermore, by insert-molding the rotor unit 5 and the stator unit 1 using an optimal resin, the number of structural components can be reduced, and an outer rotor type motor with good assemblability can be provided at a low cost.

[0053] In the outer rotor type motor, the motor gear 8 c does not necessarily need to be formed integrally with the rotor hub 8 .

Claims

1. An outer rotor type electric motor, wherein a rotor of the outer rotor type electric motor is rotatably assembled on the radially outer side of a stator, characterized in that: include: a stator unit comprising a stator core, an insulator, and a base plate, the stator core having a plurality of pole teeth projecting radially outward from a core back portion formed in an annular shape; the insulator having a fixed shaft insert-molded with a first resin member covering the stator core and inserted into a center hole of the core back portion; the base plate being assembled with the stator core via the insulator and electrically connected to a magnetic wire wound around the pole teeth via the insulator; and A rotor unit is provided with an annular rotor magnet on the inner peripheral surface of a cup-shaped rotor yoke, and a rotor hub is insert-molded with a second resin member. The rotor hub has a cylindrical portion extending on the inner and outer surfaces of the central portion of the rotor yoke. The stator core and the substrate are assembled as a whole by fitting a plurality of substrate insertion pieces protruding from the opposite end side of the axial output of the insulator into substrate insertion holes, the fixed shaft is inserted into the cylindrical hole of the rotor hub, and the stator unit and the rotor unit are assembled in such a manner that the rotor magnet and the pole teeth are opposed to each other, and the rotor unit is assembled so as to be able to slide and rotate around the fixed shaft.

2. The outer rotor type motor according to claim 1, wherein The substrate insertion piece is formed with a step portion that is inserted into the substrate insertion hole of the substrate and abuts against the insertion surface side, and a substrate fixing portion whose front end portion extends to the opposite surface side and is fixed.

3. The outer rotor type motor according to claim 1 or 2, wherein: The insulator is provided with the substrate insertion pieces corresponding to the pole teeth of the stator core, and support legs are provided between the substrate insertion pieces corresponding to the pole teeth to abut against and support the substrate.

Images