JP5005064B2 - Electric motor rotor, electric motor, method of manufacturing electric motor rotor, and air conditioner - Google Patents

Description

  The present invention relates to an electric motor rotor using a rolling bearing, and more particularly to an electric motor rotor suitable for an electric motor driven by an inverter. The present invention also relates to an electric motor using the rotor of the electric motor, a method for manufacturing the rotor of the electric motor, and an air conditioner equipped with the electric motor.

  Conventionally, when an electric motor is operated using an inverter, the carrier frequency of the inverter is set high for the purpose of reducing the noise of the electric motor that occurs due to switching of the transistors in the power circuit. As the carrier frequency is set higher, the shaft voltage generated on the shaft of the motor based on the high frequency induction increases, and the potential difference existing between the inner ring and the outer ring of the rolling bearing supporting the shaft increases. This makes it easier for current to flow through the rolling bearing. The current flowing through the rolling bearings causes corrosion called electro-corrosion on the rolling surfaces of both the inner and outer ring raceways and the rolling elements (balls and rollers that roll between the inner and outer rings), thereby deteriorating the durability of the rolling bearings. There was a problem.

  Therefore, in order to obtain an electric motor that is easy to assemble with a simple configuration that can prevent electric current from flowing through the rolling bearing provided between the shaft and the motor case and prevent electric corrosion from occurring in the rolling bearing. A stator around which a coil is wound, a frame for fixing the stator, a rotor facing the stator with a slight gap, and the rotor are fixed, and can be freely rotated via a rolling bearing. In an electric motor having a shaft to be supported and a bearing bracket that supports a rolling bearing via an insulating material, a concave portion is provided on a side of the bearing bracket that contacts the insulating material, and a convex portion corresponding to the concave portion of the bearing bracket is provided. There has been proposed an electric motor in which a convex portion of an insulating material is fitted and fixed to a concave portion of a bearing bracket (for example, see Patent Document 1).

  In the case of an electric corrosion prevention type rolling bearing in which an insulating coating is formed on the inner ring fitting surface or the outer ring fitting surface of the rolling bearing, or both the inner ring fitting surface and the outer ring fitting surface, the peripheral surface of the inner ring fitting surface or the outer ring fitting surface. An anti-corrosion-type rolling bearing has been proposed in which the boundary surface between the peripheral surface and the chamfered portion exhibits a loosely tapered surface or an arc surface with a large curvature radius, and at least one fitting surface has an insulating coating of an inorganic compound by thermal spraying. (For example, refer to Patent Document 2).

JP 2000-156952 A JP 59-103023 A

  However, the electric motor disclosed in Patent Document 1 has a concave portion provided on the side of the bearing bracket that contacts the insulating material, and the convex portion of the insulating material provided with a convex portion corresponding to the concave portion of the bearing bracket is fitted into the concave portion of the bearing bracket. However, since it is configured to be fixed, it is easy to assemble with a simple configuration, but on the other hand, there is a problem that it is easily detached from the insulating material from the bearing bracket.

  Further, the electric corrosion prevention type rolling bearing of Patent Document 2 has a loosely tapered surface or an arc surface having a large curvature radius at the peripheral surface of the inner ring fitting surface or the boundary surface between the peripheral surface of the outer ring fitting surface and the chamfered portion, and at least On the other hand, since an insulating coating of an inorganic compound is formed by thermal spraying on the fitting surface, there is a problem that the cost increases.

  The present invention has been made to solve the above-described problems, and in order to suppress the electrolytic corrosion of the bearing, it is possible to reliably fix the insulating shaft portion constituting the non-load side end portion of the shaft by a simple method. An electric motor rotor, an electric motor, a method for manufacturing the electric motor rotor, and an air conditioner are provided.

The rotor of the electric motor according to the present invention is such that a rotor magnet and a shaft are integrated by a resin portion, and rolling bearings are arranged on both axial end surfaces of the resin portion formed on the outer periphery of the shaft. In
The shaft
A shaft main body forming a shaft main body and supporting a load-side rolling bearing;
An anti-load-side rolling bearing provided on the anti-load side end of the shaft main body, and having an insulating shaft portion having insulation properties;
The anti-load side end surface of the shaft main body is formed inside the anti-load side axial end surface of the resin portion.

  In the rotor of the electric motor according to the present invention, the shaft forms a main body of the shaft, and is provided at a shaft main body portion supporting the load side rolling bearing, and an anti-load side end portion of the shaft main body portion. And an insulating shaft portion having an insulating property, and the anti-load side end surface of the shaft body portion is embedded in the resin portion of the insulating shaft portion formed inside the anti-load side axial end surface of the resin portion By providing a plurality of convex portions formed at substantially equal intervals in the circumferential direction in the vicinity of the end surface on the side to be provided and having apexes in the vicinity of the end surface, the end portion on the side opposite to the load side of the shaft is provided to suppress the electrolytic corrosion of the bearing. The insulating shaft portion to be configured can be reliably fixed by a simple method.

FIG. 3 shows the first embodiment and is a cross-sectional view of the electric motor 100. FIG. 3 shows the first embodiment and is a cross-sectional view of the mold stator 10. FIG. 3 shows the first embodiment, and is a cross-sectional view showing a state where a rotor 20 is inserted into a mold stator 10. FIG. 5 shows the first embodiment, and is a cross-sectional view of the bracket 30. FIG. 5 shows the first embodiment, and is a perspective view of a stator 40. FIG. 3 shows the first embodiment and is a cross-sectional view of a rotor 20. FIG. 5 shows the first embodiment, and is a cross-sectional view of the rotor 20-1 from which a load-side rolling bearing 21a and an anti-load-side rolling bearing 21b are removed. Fig. 5 shows the first embodiment, and is a side view of the rotor 20-1 viewed from the load side. FIG. 5 shows the first embodiment, and is a perspective view of a shaft 23. FIG. 6 shows the first embodiment, and shows a state immediately before inserting an insulating shaft portion 60 into the shaft main body portion 23e. FIG. 5 shows the first embodiment, and is a perspective view of the state immediately before the insulating shaft portion 60 is inserted into the shaft main body portion 23e as viewed from the insulating shaft portion 60 side. FIG. 5 shows the first embodiment, and is a perspective view of the state immediately before inserting the insulating shaft portion 60 into the shaft main body portion 23e as viewed from the shaft main body portion 23e side. FIG. 5 shows the first embodiment, and is an enlarged sectional view in the vicinity of an insulating shaft portion 60 of the rotor 20-1. FIG. 5 is a diagram showing the first embodiment, and is an enlarged cross-sectional view in the vicinity of an insulating shaft portion 60 of the rotor 20. FIG. 2 is a diagram illustrating the first embodiment, and is a diagram illustrating an insulating shaft portion 60 ((a) is a side view, and (b) is a front view). FIG. 4 is a diagram showing the first embodiment and is a perspective view showing an insulating shaft portion 60. The B section enlarged view of FIG. The figure which shows Embodiment 1 and is the enlarged side view which looked at the convex part 60g from the end surface 60d side. The A section enlarged view of FIG. FIG. 3 is a diagram illustrating the first embodiment and is a diagram illustrating a resin magnet 22 of a rotor ((a) is a left side view, (b) is a CC cross-sectional view of (a), and (c) is a right side view). FIG. 5 is a diagram illustrating the first embodiment and is a diagram illustrating a position detection resin magnet 25 ((a) is a left side view, (b) is a front view, and (c) is an enlarged view of a portion D in (b)). FIG. 5 shows the first embodiment, and is a cross-sectional view of a rotor 20a of a first modification. FIG. 5 shows the first embodiment, and is a perspective view of a shaft 23-1 of a first modification. FIG. 5 shows the first embodiment, and is a perspective view of the state immediately before inserting the insulating shaft portion 70 into the shaft main body portion 23e as viewed from the insulating shaft portion 70 side. FIG. 5 shows the first embodiment and is a diagram showing an insulating shaft portion 70 ((a) is a front sectional view, (b) is a side view). FIG. 5 is a diagram showing the first embodiment, and is a perspective view showing an insulating shaft portion 70. FIG. 5 shows the first embodiment, and is a cross-sectional view of a rotor 20b of a second modification. FIG. 5 shows the first embodiment and is a front view of a shaft 23-2 of a second modification. FIG. 5 shows the first embodiment and is a diagram showing an insulating shaft portion 80 ((a) is a front sectional view, (b) is a side view). FIG. 5 shows the first embodiment, and is a cross-sectional view of a rotor 20c of a third modification. FIG. 9 shows the first embodiment and is a front view of a shaft 23-3 of a third modification. FIG. 3 is a diagram illustrating the first embodiment and is a diagram illustrating an insulating shaft portion 90 ((a) is a front sectional view, and (b) is a side view). FIG. 6 shows the first embodiment, and is a cross-sectional view of a rotor 20d of a fourth modification. FIG. 5 shows the first embodiment and is a front view of a shaft 23-4 of a fourth modification. FIG. 5 shows the first embodiment and is a diagram showing an insulating shaft portion 95 ((a) is a front sectional view, (b) is a side view). FIG. 10 shows the first embodiment, and is a cross-sectional view of a rotor 20e of a fifth modification. FIG. 5 shows the first embodiment and is a configuration diagram of a drive circuit 200 that drives the electric motor 100; FIG. 5 shows the first embodiment, and shows a manufacturing process of the rotor 20. FIG. 5 shows the second embodiment and is a configuration diagram of an air conditioner 300.

Embodiment 1 FIG.
Embodiment 1 of the present invention will be described below with reference to the drawings. FIG. 1 shows the first embodiment and is a cross-sectional view of an electric motor 100. An electric motor 100 shown in FIG. 1 includes a mold stator 10, a rotor 20 (defined as a rotor of the electric motor), and a metal bracket 30 attached to one axial end of the mold stator 10. The electric motor 100 is, for example, a brushless DC motor having a permanent magnet in the rotor 20 and driven by an inverter.

  FIG. 2 is a diagram showing the first embodiment, and is a cross-sectional view of the mold stator 10. The mold stator 10 is open at one axial end (the right side in FIG. 2), and an opening 10b is formed here. The rotor 20 is inserted from this opening 10b. A hole 11a that is slightly larger than the diameter of the shaft 23 of the rotor 20 is formed in the other axial end portion of the mold stator 10 (left side in FIG. 2). Other configurations of the mold stator 10 will be described later.

  FIG. 3 shows the first embodiment, and is a cross-sectional view showing a state where the rotor 20 is inserted into the mold stator 10. The rotor 20 inserted from the opening 10b (see FIG. 2) at one end of the mold stator 10 in the axial direction has a shaft 23 on the load side at the hole 11a at the other end in the axial direction of the mold stator 10 (see FIG. 2). ) To the outside (left side of FIG. 3). Then, the load-side rolling bearing 21a of the rotor 20 (an example of a rolling bearing) is pushed in until it abuts on the bearing support portion 11 at the axial end of the mold stator 10 on the side opposite to the opening 10b. At this time, the load-side rolling bearing 21a is supported by the bearing support portion 11 formed at the axial end of the mold stator 10 on the side opposite to the opening 10b.

  The rotor 20 is integrated with the shaft 23 on the anti-load side by a resin portion 24 described later, is made of resin, and has an insulating shaft portion 60 (right side in FIG. 1) having an insulating property on the anti-load-side rolling bearing 21b (rolling). An example of a bearing) is attached (generally by press fitting). Details of the insulating shaft portion 60 will be described later.

  FIG. 4 shows the first embodiment, and is a cross-sectional view of the bracket 30. The opening 10b of the mold stator 10 is closed, and the bracket 30 that supports the anti-load-side rolling bearing 21b is press-fitted into the mold stator 10. The bracket 30 supports the anti-load-side rolling bearing 21b with a bearing support portion 30a. The bracket 30 is press-fitted into the mold stator 10 by using a press-fit portion 30b having a substantially ring shape of the bracket 30 and a U-shaped cross section as an opening 10b in the inner peripheral portion 10a (mold resin portion) of the mold stator 10. This is done by press-fitting to the side. The outer diameter of the press-fit portion 30b of the bracket 30 is larger than the inner diameter of the inner peripheral portion 10a of the mold stator 10 by the press-fit allowance. The material of the bracket 30 is made of metal, for example, a galvanized steel plate. However, it is not limited to galvanized steel sheet.

  Since the present embodiment is characterized by the structure of the rotor 20, the mold stator 10 will be briefly described.

  A mold stator 10 shown in FIG. 2 includes a stator 40 and a mold resin 50 for molding. For the mold resin 50, for example, a thermosetting resin such as an unsaturated polyester resin is used. The stator 40 is attached to a substrate and the like which will be described later, and has a weak structure. Therefore, thermosetting resins such as unsaturated polyester resins are used.

FIG. 5 is a perspective view of the stator 40 showing the first embodiment. The stator 40 shown in FIG. 5 has the following configuration.
(1) An electromagnetic steel sheet having a thickness of about 0.1 to 0.7 mm is punched into a strip shape, and a strip-shaped stator core 41 is manufactured by laminating by caulking, welding, bonding, or the like. The strip-shaped stator core 41 includes a plurality of teeth (not shown). The inside of which concentrated coil 42 described later is applied is a tooth.
(2) The insulating portion 43 is applied to the teeth. The insulating portion 43 is formed integrally with or separately from the stator core 41 using, for example, a thermoplastic resin such as PBT (polybutylene terephthalate).
(3) Concentrated winding coil 42 is wound around the teeth provided with insulating portion 43. A plurality of concentrated winding coils 42 are connected to form, for example, a three-phase single Y-connection winding. However, distributed winding may be used.
(4) Since it is a three-phase single Y connection, a terminal 44 (power supply to which power is supplied) is connected to the connection side of the insulating portion 43 to the coil 42 of each phase (U phase, V phase, W phase). Terminal 44a and neutral point terminal 44b) are assembled. There are three power terminals 44a and three neutral point terminals 44b.
(5) The board | substrate 45 is attached to the insulation part 43 (side in which the terminal 44 is assembled | attached) on the connection side. A substrate 45 on which a lead wire lead-out component 46 that leads out the lead wire 47 is assembled is assembled to the insulating portion 43 to form the stator 40. The chamfered rectangular column 48 of the insulating part 43 formed in the stator core 41 is inserted into a rectangular column insertion hole (not shown) provided in the substrate 45, thereby positioning in the rotational direction and the insulating unit 43. The position in the axial direction is determined by installing the substrate 45 on the substrate installation surface (not shown). Further, by thermally welding the prisms 48 protruding from the substrate 45, the substrate 45 and the insulating portion 43 are fixed, and the portion protruding from the substrate 45 of the terminal 44 provided in the stator 40 is electrically soldered. Are also joined. On the substrate 45, an IC 49a (drive element) for driving the electric motor 100 (for example, a brushless DC motor), a Hall IC 49b (position detection element, see FIG. 1) for detecting the position of the rotor 20, and the like are mounted. IC 49a, Hall IC 49b, etc. are defined as electronic components.

  Next, the configuration of the rotor 20 will be described. 6 to 8 show the first embodiment. FIG. 6 is a sectional view of the rotor 20. FIG. 7 is a sectional view of the rotor 20-1 from which the load side rolling bearing 21a and the anti-load side rolling bearing 21b are removed. 8 and 8 are side views of the rotor 20-1 as viewed from the load side.

  As shown in FIGS. 6 and 7, the rotor 20 (or the rotor 20-1) includes a shaft 23 provided with a knurling 23a, a ring-shaped rotor resin magnet 22 (an example of a rotor magnet), A ring-shaped position detecting resin magnet 25 (an example of a position detecting magnet) and a resin portion 24 for integrally molding them.

  A load 20 side rolling bearing 21 a and an anti-load side rolling bearing 21 b are attached to the rotor 20-1 to form the rotor 20.

  A resin magnet 22 of a ring-shaped rotor, a shaft 23, and a position detection resin magnet 25 are integrated by a resin portion 24 injected by a vertical molding machine. At this time, the resin portion 24 is formed on the outer periphery of the shaft 23, with a central cylindrical portion 24g (resin portion, formed inside the rotor resin magnet 22), which will be described later, and the rotor resin magnet 22 in the center. It has a plurality of axial ribs 24j (see FIG. 8) that are radially formed around the shaft 23 and connected to the cylindrical portion 24g. A cavity 24k (see FIG. 8) penetrating in the axial direction is formed between the ribs 24j.

  A thermoplastic resin such as PBT (polybutylene terephthalate) or PPS (polyphenylene sulfide) is used for the resin used for the resin portion 24. Those in which a glass filler is blended with these resins are also suitable.

  The anti-load side rolling bearing 21b is attached to the insulating shaft portion 60 (right side in FIG. 6) of the anti-load side shaft 23 (generally, by press fitting). A load-side rolling bearing 21a is attached to a load-side shaft 23 (left side in FIG. 6) to which a fan or the like is attached.

  Since the load side rolling bearing 21a and the anti-load side rolling bearing 21b are well-known rolling bearings, detailed description is omitted.

  The load-side rolling bearing 21a includes an inner ring 21a-1 that is press-fitted into the shaft 23, an outer ring 21a-2 that is supported by the bearing support portion 11 of the mold stator 10, and an inner ring 21a-1 and an outer ring 21a-2. And rolling elements 21a-3 that roll. A ball or a roller is used for the rolling element 21a-3.

  The anti-load-side rolling bearing 21b includes an inner ring 21b-1 that is press-fitted into the insulating shaft part 60 of the shaft 23, an outer ring 21b-2 that is supported by the bearing support part 30a of the bracket 30, and an inner ring 21b-1 and an outer ring 21b-. 2 and rolling elements 21b-3 that roll between the two. A ball or a roller is used for the rolling element 21b-3.

  In this embodiment, the anti-load-side rolling bearing 21b supported by a metal (having conductivity) bracket 30 is press-fitted into the insulating shaft portion 60 of the shaft 23, and the insulating shaft portion 60 is insulated to generate axial current. It is characterized by suppressing the occurrence of electrolytic corrosion of the anti-load side rolling bearing 21b by suppressing.

  As will be described later, the insulating shaft portion 60 of the shaft 23 has a small diameter portion 60b (see FIG. 10) in a recess 23h (see FIG. 10) of the shaft main body portion 23e (made of conductive metal) of the shaft 23. A protrusion, see FIG. 10) is inserted. When the shaft body 23e, the ring-shaped rotor resin magnet 22 and the ring-shaped position detecting resin magnet 25 are integrated by the resin portion 24, the insulating shaft portion 60 is also integrated (for example, FIG. 13).

  The outer diameters of the shaft main body portion 23e and the insulating shaft portion 60 (large diameter portion 60a (see FIG. 10)) are substantially the same.

  Thus, since the insulating shaft portion 60 inserted into the shaft 23 is integrated and fixed by the resin portion 24, fixing of the insulating shaft portion 60 becomes extremely simple and reliably fixed, and the shaft 23 is insulated from the insulating shaft. The possibility that the part 60 will come off is reduced.

  The present embodiment also includes a rotor 20 that does not have the ring-shaped position detecting resin magnet 25.

  The shaft current flowing through the load-side rolling bearing 21a is small as the shaft current flowing through the anti-load-side rolling bearing 21b is reduced by the insulating shaft portion 60 provided between the anti-load-side rolling bearing 21b and the shaft body 23e. Therefore, the shaft 23 may not be insulated.

  9 to 12 are diagrams showing the first embodiment, FIG. 9 is a perspective view of the shaft 23, FIG. 10 is a diagram showing a state immediately before the insulating shaft portion 60 is inserted into the shaft main body portion 23e, and FIG. The perspective view which looked at the state just before inserting the insulated shaft part 60 in the main-body part 23e from the insulated shaft part 60 side, FIG. 12 shows the state just before inserting the insulated shaft part 60 in the shaft main-body part 23e side shaft side 23e side It is the perspective view seen from.

  As shown in FIG. 9, the shaft 23 includes a shaft main body portion 23 e and an insulating shaft portion 60. The shaft main body 23e and the insulating shaft 60 are configured to have substantially the same outer diameter.

  As shown in FIGS. 10 to 12, the shaft main body 23e and the insulating shaft 60 are formed by inserting the small-diameter portion 60b of the insulating shaft 60 into the recess 23h formed at the opposite end of the shaft main body 23e. The At this stage, it has been inserted but not integrated. When the rotor 20-1 is assembled, the insulating shaft portion 60 inserted into the shaft main body portion 23 e is integrated and fixed by the resin portion 24.

  FIG. 13 shows the first embodiment, and is an enlarged cross-sectional view of the vicinity of the insulating shaft portion 60 of the rotor 20-1. As shown in FIG. 13, the insulating shaft portion 60 in which the small diameter portion 60 b is inserted into the concave portion 23 h of the shaft main body portion 23 e is integrated by the resin portion 24. The rotation prevention and retaining of the insulating shaft portion 60 will be described later.

  In FIG. 13, the diameter d2 of the large-diameter portion 60a (the bearing fitting portion, the portion into which the anti-load-side rolling bearing 21b is press-fitted) of the insulating shaft portion 60 of the shaft 23 on which the anti-load-side rolling bearing 21b is held is expressed as follows. 23 is substantially the same as the diameter d1 of the shaft body 23e.

  Further, since the anti-load-side rolling bearing 21b is press-fitted and held in the large-diameter portion 60a of the insulating shaft portion 60, the insulating shaft portion 60 side (anti-load side) end surface of the central cylindrical portion 24g of the resin portion 24 is insulated. The distance L1 between the large-diameter portion 60a of the shaft portion 60 and the anti-load side (right side in FIG. 13) is larger than the axial length of the anti-load side rolling bearing 21b.

  The resin portion 24 has a bearing abutment surface 24d which is positioned in the axial direction when the anti-load-side rolling bearing 21b is inserted into the insulating shaft portion 60 of the shaft 23. The knurled 23a of the shaft main body portion 23e is centered in the axial direction. It is formed at the opposite end of the central cylindrical portion 24g (resin portion) of the resin portion 24 formed on the outer periphery.

  A step 24e is provided between the outer peripheral portion of the central cylindrical portion 24g and the bearing contact surface 24d on the central cylindrical portion 24g of the resin portion 24 formed on the outer periphery with the knurl 23a of the shaft 23 as an axial center. Is provided.

  FIG. 14 is a diagram showing the first embodiment, and is an enlarged cross-sectional view of the vicinity of the insulating shaft portion 60 of the rotor 20. It is essential that the diameter d3 of the stepped portion 24e of the central cylindrical portion 24g of the resin portion 24 is smaller than the inner diameter d4 of the outer ring 21b-2 of the anti-load side rolling bearing 21b. In the rotor 20 shown in FIG. 6 (FIG. 14), the diameter d3 of the stepped portion 24e is substantially the same as or slightly smaller than the outer diameter d5 of the inner ring 21b-1 of the anti-load side rolling bearing 21b.

  Generally, a rolling bearing is provided with a cover between an outer ring and an inner ring so that grease does not leak out from the inside of the rolling bearing or dust does not enter from the outside. This cover is located inside the both end faces of the rolling bearing.

  Therefore, even if the diameter d3 of the stepped portion 24e is larger than the outer diameter d5 of the inner ring 21b-1 of the anti-load-side rolling bearing 21b, a portion (stepped portion 24e) that is larger than the outer diameter d5 of the inner ring 21b-1 is still present. The anti-load side rolling bearing 21b does not contact. Therefore, it is practical that the diameter d3 of the stepped portion 24e is substantially the same as or slightly smaller than the outer diameter d5 of the inner ring 21b-1 of the anti-load-side rolling bearing 21b.

  By providing the stepped portion 24e, when the shaft 23, the resin magnet 22 of the rotor and the resin magnet 25 for position detection are integrally formed of resin, the bearing contact surface 24d of the central cylindrical portion 24g of the resin portion 24 is erected. In the case of forming, the step portion 24e is formed by the above-mentioned eroko. Therefore, since the mating surface of the mold is the anti-load side end surface 24h of the central cylinder portion 24g, the anti-load side rolling bearing 21b is the anti-load that becomes the mating surface of the mold even if burrs occur on the mating surface of the mold. Since the stepped portion 24e is separated from the side end surface 24h, the burr does not come into contact with the anti-load side rolling bearing 21b. Therefore, there is little possibility of adversely affecting the anti-load side rolling bearing 21b.

  Further, when the rotor 20 receives a thermal shock, the central cylindrical portion 24g of the resin portion 24 may break. Even in such a case, the step portion 24e is provided in the central cylindrical portion 24g, the radial dimension of the step portion 24e is constant, and the diameter of the central cylindrical portion 24g between the step portions 24e (the load side and the anti-load side) at both ends. The thickness of the direction can be increased to cope with it.

  The diameter d3 of the stepped portion 24e is set to the inner diameter d4 of the outer rings 21a-2 and 21b-2 of the load side rolling bearing 21a and the anti-load side rolling bearing 21b (the inner diameter of the outer ring 21a-2 is not shown, but the inner diameter of the outer ring 21b-2). Therefore, the thickness in the radial direction of the central cylindrical portion 24g between the stepped portions 24e can be made larger than the inner diameter d4 of the outer rings 21a-2 and 21b-2.

  FIGS. 15 to 19 are diagrams showing the first embodiment, FIG. 15 is a diagram showing the insulating shaft portion 60 ((a) is a side view, (b) is a front view), and FIG. 16 shows the insulating shaft portion 60. FIG. 17 is an enlarged view of a portion B in FIG. 16, FIG. 18 is an enlarged side view of the convex portion 60g viewed from the end surface 60d side, and FIG. 19 is an enlarged view of the portion A in FIG.

  The insulating shaft portion 60 will be described with reference to FIGS. 15 to 19. As shown in the figure, the insulating shaft portion 60 includes a substantially cylindrical large-diameter portion 60a and a substantially cylindrical small-diameter portion 60b protruding in the axial direction from the axial end surface of the large-diameter portion 60a on the shaft main body 23e side. With. The large diameter part 60a and the small diameter part 60b are substantially concentric. And the diameter of the small diameter part 60b is smaller than the diameter of the large diameter part 60a.

The large-diameter portion 60a of the insulating shaft portion 60 includes a plurality of convex portions 60g having the following configuration at the end of the resin portion 24 on the central cylindrical portion 24g side.
(1) In the vicinity of the end surface 60d on the side embedded in the resin portion 24 formed on the outer periphery of the shaft 23 of the large diameter portion 60a of the insulating shaft portion 60, first, the shape of the end surface 60d is a predetermined distance from the outer periphery. The distant position is defined as a vertex 60g-1, and a large diameter portion at an equal angle (α) on both sides with respect to a radius passing through the vertex 60g-1 (a line connecting the vertex 60g-1 and the center of the outer circumference of the large diameter portion 60a). It is a substantially triangular shape that intersects at the intersection points a and b with the outer circle of 60a (see FIG. 18).
(2) Secondly, the shape in the axial direction from the end surface 60d is a convex portion 60g facing the outer peripheral surface 60a-1 of the large diameter portion 60a in the axial direction at a predetermined angle (β) from the vertex 60g-1. (See FIG. 19).
(3) As shown in FIG. 15A, the plurality of convex portions 60g are formed at substantially equal intervals in the circumferential direction. In the example of FIG. 15A, seven convex portions 60g are formed at approximately 45 ° intervals.

  The large-diameter portion 60a of the insulating shaft portion 60 has a resin injection gate gate cutting portion 60c extending in the axial direction with a predetermined width and having a predetermined height (radial direction) in the vicinity of the end surface 60d during resin molding. As shown in FIG. 15 (a), each of the two convex portions 60g is located at a substantially central portion of the two convex portions 60g at an interval of approximately 45 °.

  The shape of the convex portion 60g is “substantially triangular pyramid” in a nutshell. One of the four corners of the triangular pyramid is the apex at the end face 60d, and the two corners are located at the intersection points a and b where the end face 60d intersects the outer circumference circle of the large diameter part 60a, and the remaining one corner is It is located on the outer peripheral surface 60a-1 on the inner side in the axial direction from the end surface 60d.

  The convex portion 60g of the large diameter portion 60a of the insulating shaft portion 60 shown in FIGS. 15 to 19 is an example, and the shape thereof is not limited to “substantially triangular pyramid”. The convex portion 60g has a vertex in the vicinity of the end surface 60d of the large-diameter portion 60a, and any configuration may be used as long as the convex portion 60g faces the outer peripheral surface 60a-1 for a while in the circumferential direction or the axial direction. And the outer peripheral surface of the convex part 60g may not be a plane, but may be a curved surface.

  When the insulating shaft portion 60 is integrated with the shaft body portion 23e by the resin portion 24, the central cylindrical portion 24g covers and integrates the convex portion 60g near the end surface 60d of the large diameter portion 60a of the insulating shaft portion 60. The movement of the insulating shaft portion 60 in the axial direction and the circumferential direction is suppressed (rotation prevention and retaining prevention).

  When the convex portion 60g of the insulating shaft portion 60 is embedded in the central cylindrical portion 24g of the resin portion 24 formed on the outer periphery of the shaft 23, the outer peripheral surface 60a-1 of the large-diameter portion 60a of the insulating shaft portion 60 is The convex portion 60g is made to reach the outer peripheral surface 60a-1 at an equal angle (α) from a predetermined (end surface 60d) vertex 60g-1 (see FIG. 18). Thereby, since the space between the convex portions 60g becomes a part of the central cylindrical portion 24g of the resin portion 24, the thickness of the central cylindrical portion 24g of the resin portion 24 in the vicinity of the end surface 60d of the large diameter portion 60a of the insulating shaft portion 60 is reduced. It can be secured.

  Further, by causing the convex portion 60g of the insulating shaft portion 60 to reach the outer peripheral surface 60a-1 of the large-diameter portion 60a of the insulating shaft portion 60 at a predetermined angle (β) with respect to the axial direction from the vertex 60g-1. (Refer FIG. 19) and the thickness in the axial direction end surface vicinity of the center cylinder part 24g of the resin part 24 are securable.

  By forming the convex portion 60g that prevents and prevents the insulating shaft portion 60 integrally formed with the resin portion 24 from being formed as described above, the central cylindrical portion 24g of the resin portion 24 is formed in the vicinity of the convex portion 60g. The Therefore, the thickness of the central cylinder part 24g of the resin part 24 can be ensured. Thereby, cost reduction and quality can be ensured.

  Since the electric motor 100 (including the rotor 20) is used outdoors, thermal shock resistance is required. The resin portion 24 made of a thermoplastic resin such as PBT (polybutylene terephthalate) or PPS (polyphenylene sulfide) and the shaft 23 made of iron have different linear expansion coefficients. There is a possibility that the central tube portion 24g of the resin portion 24 may break. Therefore, the center cylinder part 24g of the resin part 24 needs a predetermined thickness. By forming the convex portion 60g to prevent and prevent the insulating shaft portion 60 integrally formed with the resin portion 24 from being formed as described above, the wall thickness of the central cylindrical portion 24g of the resin portion 24 near the convex portion 60g is formed. Can be secured without increasing the outer diameter of the central cylindrical portion 24g.

  When the resin injection port is on the outer periphery of the insulating shaft portion 60, if the gate cutting portion 60c remains as a projection (protruding portion), the rolling bearing inner diameter and the gate cutting portion 60c are not inserted when the bearing (anti-load-side rolling bearing 21b) is inserted. It is expected that unexpected stress is generated due to contact, and that the quality is deteriorated due to the gate cutting portion 60c being cut and adhering as dust.

  Further, when the resin injection port is provided on the opposite surface of the end surface 60 d having the convex portion 60 g of the large diameter portion 60 a of the insulating shaft portion 60, the resin magnet 22 of the rotor and the shaft 23 are integrated with the resin portion 24. At the time of molding, the gate cutting portion 60c of the resin injection port comes to the portion that comes into contact with the mold. Therefore, when the gate cutting portion 60c remains as a protrusion (protruding portion), the surface is not secured and the resin portion 24 is not secured. It becomes difficult to ensure the dimensions during molding, or when the mold is tightened, the gate cutting part 26c of the resin injection port is crushed and adheres to the mold as dust, and the gate cutting part 26c Even when there is no remaining, it is difficult to ensure the dimensions during molding, and there is a concern that the quality may deteriorate. Further, in the case where the end surface 60d of the insulating shaft portion 60g having the convex portion 60g is provided with a resin injection port on the surface in contact with the shaft, when the insulating shaft portion 60 is installed on the shaft 23, the gate cutting portion 60c protrudes (projects). In the case where it remains as (part), since the surface is not secured, it is difficult to secure the dimensions during molding, and there is a concern that the quality may deteriorate.

  On the other hand, by providing the resin injection port in the portion embedded in the resin part 24, the above-mentioned concern is eliminated, and even if the gate cutting part 60c becomes a convex part or a concave part, the resin is injected. As a result, the gate cutting part 60c functions as a stopper around the insulating shaft part 60, so that the quality can be improved.

As the material of the insulating shaft portion 60, it is preferable to use a resin material having a linear expansion coefficient substantially the same as that of iron (the shaft main body portion 23e). As such a resin material, for example, a BMC resin of a thermosetting resin can be given. BMC (bulk molding compound) resin is a block clay-like thermosetting resin in which various additives are added to an unsaturated polyester resin. BMC resin has the following characteristics.
(1) Good productivity due to shorter curing time than epoxy resin;
(2) Good balance between material cost and properties;
(3) Possible to mold at low pressure;
(4) High dimensional stability;
(5) High surface hardness and hardly scratched;
(6) Lighter than metal, excellent in moldability of complex shapes, and excellent in vibration absorption. Further, in the present embodiment, the insulating shaft portion 60 made of a thermosetting resin is disclosed. However, it goes without saying that the present invention is applied to other materials such as ceramic as long as the configuration is the same.

  In the rotor of the electric motor, stress is generated when the thermal history of rising and falling heat is received and the linear expansion coefficients of iron and resin are different. For this reason, the resin undergoes a creep phenomenon (a phenomenon in which the deformation of the material increases with time under a constant load), and the initial dimensions of the part into which the bearing (bearing) is inserted cannot be maintained. Sometimes. In that case, creep of the inner ring of the bearing (bearing) (a phenomenon in which a minute gap is generated between the inner ring and the shaft and the contact position shifts by the difference in circumference every rotation) may be caused, and there is a concern about the deterioration of the quality. The On the other hand, quality can be improved by using a thermosetting resin having high creep resistance and using a BMC resin having a linear expansion coefficient close to that of iron.

  20A and 20B are views showing the resin magnet 22 of the rotor, in which FIG. 20A is a left side view, FIG. 20B is a cross-sectional view taken along the line CC of FIG. The configuration of the resin magnet 22 of the ring-shaped rotor will be described with reference to FIG. In the rotor resin magnet 22, an axial end of the inner diameter (on the right side in FIG. 20B) is secured to ensure coaxiality between the shaft 23 and the rotor resin magnet 22 during mold clamping during resin molding. The notch 22a is formed. In the example of FIG. 20, the notches 22a are formed at eight locations at substantially equal intervals in the circumferential direction (FIG. 20 (c)).

  Further, the rotor resin magnet 22 is formed with pedestals 22b on the end face of the other end in the axial direction (left side in FIG. 20B) on which the position detecting resin magnet 25 is placed at substantially equal intervals in the circumferential direction. ing.

  The pedestal 22b is formed from the vicinity of the inner diameter of the resin magnet 22 of the rotor toward the outer diameter, and the positioning projection 22c is radially directed from the tip of the pedestal 22b toward the outer periphery of the resin magnet 22 of the rotor. It extends to. The positioning protrusions 22c are used for positioning the rotor resin magnet 22 in the circumferential direction (rotation direction) when the rotor magnet, the position detection magnet, and the shaft are integrally formed by the resin portion 24.

  FIG. 21 is a diagram showing the first embodiment, and is a diagram showing the position detecting resin magnet 25 ((a) is a left side view, (b) is a front view, and (c) is an enlarged view of a D portion of (b)). It is. The configuration of the ring-shaped position detection resin magnet 25 will be described with reference to FIG.

  The position detecting resin magnet 25 includes steps 25b at both axial end portions on the inner diameter side. The step 25b is necessary to prevent the position detecting resin magnet 25 from coming off in the axial direction by filling the step 25b on the axial end portion side of the rotor 20 with a part of the resin portion 24.

  In FIG. 21, the step provided with the step 25 b at both ends is shown, but the step 25 b may be provided at either one end, and it should be positioned on the axial end portion side of the rotor 20. However, the one provided with the step 25b at both ends can be set without worrying about the front and back when setting the resin magnet 25 for position detection on the mold when the resin portion 24 of the rotor 20 is integrally formed. Excellent.

  Further, the position detecting resin magnet 25 includes eight ribs 25a (substantially triangular in cross section) that are circumferentially detented when embedded in the resin portion 24 in the step 25b at substantially equal intervals in the circumferential direction. However, the number, shape, and arrangement interval of the ribs 25a may be arbitrary.

  As shown in FIG. 6, in the resin portion 24, a mold inner diameter holding portion 24a for holding the inner diameter of the position detecting resin magnet 25 and the position detecting resin magnet 25 are set in a mold (lower mold). A taper part 24b for facilitating and a resin injection part 24c at the time of resin molding are formed after resin molding.

  The resin magnet 22 of the rotor is formed by mixing a thermoplastic material with a magnetic material. As shown in FIG. 20, the inner diameter is provided with a notch 22a in a tapered shape from one end surface in the axial direction. A pedestal 22b on which the position detecting resin magnet 25 is placed is provided on the other axial end surface opposite to one axial end surface.

  The pedestal 22b of the rotor resin magnet 22 formed integrally with the shaft 23 enables the position detection resin magnet 25 to be separated from the end surface of the rotor resin magnet 22, and the thickness of the position detection resin magnet 25 is increased. Can be disposed at an arbitrary position, and the cost can be reduced by filling a thermoplastic resin cheaper than the resin magnet 22 of the rotor.

  As shown in FIG. 21, the position detecting resin magnet 25 has steps 25b on both sides in the thickness direction, and ribs 25a that prevent rotation when embedded in resin. Further, the coaxiality between the inner diameter of the position detecting resin magnet 25 and the outer diameter of the position detecting resin magnet 25 is made with high accuracy.

  When molded integrally with the shaft 23, the outer periphery of the position detection resin magnet 25 is filled with a taper-shaped resin (resin portion 24). Correspondingly, the resin to be filled is blocked by the axial end face (outer side) on one side of the position detection resin magnet 25 and the axial end faces of the rotor resin magnet 22, so that the outer diameter of the rotor resin magnet 22 is variable. It is possible to suppress the occurrence of the problem, and the quality is improved.

  Further, by arranging the gate port at the time of integral molding with the shaft 23 further inside than the inner diameter of the resin magnet 22 of the rotor and arranging the resin injection portion 24c in a convex shape, the concentration of pressure is alleviated, and the resin Can be easily filled, and the convex portion of the resin injection portion 24c can be used for positioning.

  FIG. 22 is a diagram showing the first embodiment, and is a cross-sectional view of the rotor 20a of the first modification. Compared to the rotor 20 shown in FIG. 6, the configuration of the shaft (insulating shaft portion) is different. The rotor 20 shown in FIG. 6 has a configuration in which the small-diameter portion 60b of the insulating shaft portion 60 is inserted into the recess 23h of the shaft main body portion 23e, whereas the rotor 20a of the first modification includes the shaft main body portion. The shaft 23-1 is configured such that a shaft main body small diameter portion 23g, which is thinner than the shaft main body portion 23e formed at the opposite end portion of 23e, is inserted into a recess 70h (described later) of the insulating shaft portion 70.

  23 and 24 are diagrams showing the first embodiment. FIG. 23 is a perspective view of the shaft 23-1 of the first modification. FIG. 24 is a diagram showing the state immediately before the insulating shaft portion 70 is inserted into the shaft main body portion 23e. It is the perspective view seen from the axial part 70 side.

  As shown in FIG. 23, the shaft 23-1 of Modification 1 includes a shaft main body portion 23e and an insulating shaft portion 70 inserted into the shaft main body portion 23e. At this stage, the shaft body portion 23e and the insulating shaft portion 70 are not fixed (only inserted). The resin portion 24 is integrated in a later process.

  Here, a portion of the insulating shaft portion 70 where the anti-load-side rolling bearing 21b is fitted is formed as a bearing fitting portion 70a, and a stepped portion 70j (see FIG. 26) is formed adjacent to the shaft fitting portion 70a. A portion where 23e is fitted is referred to as a shaft fitting portion 70b.

  As shown in FIG. 24, in the shaft 23-1 of the first modification, a shaft main body small diameter portion 23g thinner than the shaft main body portion 23e is formed at the opposite end of the shaft main body portion 23e. The shaft main body small diameter portion 23g is inserted into a recess 70h (see FIG. 25) formed in the shaft fitting portion 70b of the insulating shaft portion 70.

  25 and 26 are diagrams showing the first embodiment. FIG. 25 is a diagram showing the insulating shaft portion 70 ((a) is a front sectional view, (b) is a side view), and FIG. It is a perspective view shown. The insulating shaft portion 70 will be described with reference to FIGS. 25 and 26.

  As shown in FIG. 25A, the insulating shaft portion 70 has a substantially cylindrical shape as a whole. The insulating shaft portion 70 is formed with a substantially cylindrical shaft fitting portion 70b at an end portion on the shaft main body portion 23e side, and includes a concave portion 70h opened on the shaft main body portion 23e side inside the shaft fitting portion 70b.

  A bearing fitting portion 70a into which the anti-load-side rolling bearing 21b is fitted is connected to the shaft fitting portion 70b via a step 70j (see FIG. 26). The bearing fitting part 70a is thinner than the shaft fitting part 70b by the level difference 70j. The shape of the bearing fitting portion 70a is substantially cylindrical.

  A plurality of ribs 70g extending in the axial direction from the step 70j are formed on the outer peripheral surface of the bearing fitting portion 70a. As shown in FIG. 25 (b), seven ribs 70g are formed at approximately 45 ° intervals. The rib 70g has a substantially right-angled cross-sectional shape in the axial direction, and coincides with the outer peripheral surface of the shaft fitting portion 70b at the step 70j, and the thickness (radial dimension) of the rib 70g gradually decreases, and the outer peripheral surface of the bearing fitting portion 70a. To. However, the number of ribs 70g, the manner of arrangement, etc. may be arbitrary.

  The insulating shaft portion 70 is provided with a resin injection gate cutting portion 70c extending in the axial direction from the step 70j. The gate cutting part 70c extends in a axial direction from the step 70j with a predetermined width and has a predetermined height. As shown in FIG. 25 (b), each of the two ribs 70g is positioned at a substantially central portion of the two ribs 70g at an interval of about 45 °.

  The rib 70g mainly functions as a detent for the insulating shaft portion 70 after the insulating shaft portion 70 is integrated with the shaft main body portion 23e by the resin portion 24. However, as shown in FIGS. 25 (a) and 26, the rib 70g is inclined from the step 70j in the axial direction to the outer peripheral surface of the bearing fitting portion 70a, and thus also has a function of retaining.

  The step 70j functions as a retaining member for the insulating shaft portion 70 after the insulating shaft portion 70 is integrated with the shaft main body portion 23e by the resin portion 24.

  Compared with the rotor 20, the rotor 20 a of the first modification can reduce the amount of cutting of the shaft body 23 e or the cutting process as much as possible, thereby reducing the cost. That is, as shown in FIG. 10, the shaft main body portion 23e of the rotor 20 needs to be cut in order to form the recess 23h at the end on the side opposite to the load. On the other hand, the shaft main body portion 23e of the rotor 20a of the first modification only needs to cut the outer peripheral portion of the shaft main body portion 23e in order to form the shaft main body small diameter portion 23g at the opposite end portion on the load side. is there.

  Next, the rotor 20b of the modification 2 is demonstrated. FIG. 27 shows the first embodiment, and is a cross-sectional view of a rotor 20b of a second modification. Compared to the rotor 20 shown in FIG. 6, the configuration of the shaft (insulating shaft portion) is different. The rotor 20 shown in FIG. 6 is configured such that the small-diameter portion 60b of the insulating shaft portion 60 is inserted into the concave portion 23h of the shaft main body portion 23e, whereas the rotor 20b of the second modification has the shaft main body portion. 23e is a structure using the shaft 23-2 comprised by inserting the non-load side edge part of 23e in the recessed part 80h (after-mentioned) of the insulation shaft part 80. As shown in FIG.

  28 and 29 show the first embodiment, FIG. 28 is a front view of the shaft 23-2 of the second modification, FIG. 29 is a view showing the insulating shaft portion 80 ((a) is a front sectional view, b) is a side view).

  As shown in FIG. 28, the shaft 23-2 of the second modification includes a shaft main body portion 23 e and an insulating shaft portion 80. The recessed portion 80h of the insulating shaft portion 80 is inserted into the opposite end portion of the shaft body portion 23e. At this stage, the shaft main body 23e and the insulating shaft 80 are not fixed. In the subsequent process, the resin portion 24 is integrated.

  As shown in FIG. 29A, the insulating shaft portion 80 has a substantially cylindrical shape as a whole. The insulating shaft portion 80 has a substantially cylindrical shaft fitting portion 80b formed at an end portion on the shaft main body portion 23e side, and includes a recess 80h that opens on the shaft main body portion 23e side inside the shaft fitting portion 80b.

  A bearing fitting portion 80a into which the anti-load-side rolling bearing 21b is fitted is connected to the shaft fitting portion 80b via a step 80j (see FIG. 29B). The bearing fitting portion 80a is thinner than the shaft fitting portion 80b by the level difference 80j. The shape of the bearing fitting portion 80a is substantially cylindrical.

  A plurality of ribs 80g extending in the axial direction from the step 80j are formed on the outer peripheral surface of the bearing fitting portion 80a. As shown in FIG. 29B, seven ribs 80g are formed at approximately 45 ° intervals. The rib 80g has a substantially right-angled cross-sectional shape in the axial direction, and coincides with the outer peripheral surface of the shaft fitting portion 80b at the step 80j. To. However, the number of ribs 80g, the manner of arrangement, etc. may be arbitrary.

  The insulating shaft 80 includes a resin injection gate cutting part 80c extending in the axial direction from the step 80j. The gate cutting part 80c extends from the step 80j in the axial direction with a predetermined width and has a predetermined height. As shown in FIG. 29 (b), each of the two ribs 80g is positioned at a substantially central portion of the two ribs 80g at an interval of about 45 °.

  The rib 80g mainly functions as a detent for the insulating shaft portion 80 after the insulating shaft portion 80 is integrated with the shaft main body portion 23e by the resin portion 24. However, as shown in FIG. 29 (a), the rib 80g is inclined from the step 80j in the axial direction to the outer peripheral surface of the bearing fitting portion 80a, and thus also has a function of retaining.

  The step 80j functions as a retainer for the insulating shaft portion 80 after the insulating shaft portion 80 is integrated with the shaft main body portion 23e by the resin portion 24.

  Compared with the rotor 20, the rotor 20b of the modified example 2 can reduce cost by not cutting the shaft main body portion 23e. Further, since the insulating shaft portion 80 is directly fitted on the outer periphery of the shaft main body portion 23e, it is easy to ensure the coaxiality between the bearing fitting portion 80a of the insulating shaft portion 80 and the outer periphery of the shaft main body portion 23e. Can be improved. However, since the outer diameter of the central cylindrical portion 24g of the resin portion 24 is larger than that of the rotor 20, the cost increases.

  Next, the rotor 20c of the modification 3 is demonstrated. FIG. 30 shows the first embodiment, and is a cross-sectional view of a rotor 20c of a third modification. Compared to the rotor 20 shown in FIG. 6, the configuration of the shaft (insulating shaft portion) is different. The rotor 20 shown in FIG. 6 is configured such that the small-diameter portion 60b of the insulating shaft portion 60 is inserted into the concave portion 23h of the shaft main body portion 23e, whereas the rotor 20c of the third modification has a shaft main body portion. This is a configuration using a shaft 23-3 configured by inserting a foot portion 90h (described later) of the insulating shaft portion 90 into an end portion on the non-load side of 23e.

  FIGS. 31 and 32 are diagrams showing the first embodiment, FIG. 31 is a front view of the shaft 23-3 of the third modification, FIG. 32 is a view showing the insulating shaft portion 90 ((a) is a front sectional view, b) is a side view).

  As illustrated in FIG. 31, the shaft 23-3 of the third modification includes a shaft main body portion 23e and an insulating shaft portion 90. The foot portion 90h of the insulating shaft portion 90 is inserted into the opposite end portion of the shaft main body portion 23e. At this stage, the shaft body 23e and the insulating shaft 90 are not fixed. In the subsequent process, the resin portion 24 is integrated.

  As shown in FIG. 32A, the insulating shaft portion 90 has a substantially cylindrical shape as a whole. The insulating shaft portion 90 includes a plurality of foot portions 90h fitted to the outer periphery of the shaft main body portion 23e at the end portion on the shaft main body portion 23e side. In the example of FIG. 32, four leg portions 90h are provided. The four leg portions 90h are arranged at substantially equal intervals (90 °) in the circumferential direction. However, the number of foot portions 90h and the manner of arrangement may be arbitrary.

  The non-load side end of the shaft main body 23e is housed in a space formed inside the four legs 90h.

  A bearing fitting portion 90a into which the anti-load-side rolling bearing 21b is fitted is formed so as to be connected to the four foot portions 90h with a diameter smaller than the diameter of a contact circle in contact with the outer periphery of the four foot portions 90h. . The shape of the bearing fitting portion 90a is substantially cylindrical.

  The three leg portions 90h have the anti-load side end portion 90h-1 inclined toward the outer peripheral surface of the bearing fitting portion 90a (tapered extending to the outer peripheral surface of the bearing fitting portion 90a at a predetermined angle). One of the foot portions 90h (located approximately 45 ° apart from two of the three foot portions 90h) is positioned on the opposite end of the load-side end. A resin injection gate cutting portion 90c extending in the direction is provided. The gate cutting portion 90c has a predetermined width and extends in the axial direction from the opposite end portion of one leg portion 90h, and has a predetermined height.

  Each foot part 90h functions as a detent for the insulating shaft part 90 after the insulating shaft part 90 is integrated with the shaft body part 23e by the resin part 24.

  Further, the step 90c-1 of the gate cutting part 90c and the anti-load side end part 90h-1 of the three leg parts 90h are integrated with the shaft main body part 23e by the resin part 24. , Functioning as a retainer for the insulating shaft 90.

  In the rotor 20c of the third modification, the insulating shaft portion 90 can be easily assembled to the shaft main body portion 23e, and the cost can be reduced. Moreover, since the thickness of the central cylinder part 24g of the resin part 24 can be ensured with respect to the modified example 2, the cost can be reduced by suppressing the outer diameter of the central cylinder part 24g.

  Next, the rotor 20d of Modification 4 will be described. FIG. 33 shows the first embodiment, and is a cross-sectional view of a rotor 20d of a fourth modification. Compared to the rotor 20 shown in FIG. 6, the configuration of the shaft (insulating shaft portion) is different. The rotor 20 shown in FIG. 6 is configured such that the small-diameter portion 60b of the insulating shaft portion 60 is inserted into the concave portion 23h of the shaft main body portion 23e, whereas the rotor 20d of the modified example 4 includes the shaft main body portion. The shaft main body small diameter portion 23 g of 23 e is inserted into the recess 95 h of the insulating shaft portion 95. Furthermore, the outer periphery of the shaft fitting part 95b of the insulating shaft part 95 is provided with a plurality of ribs 95g formed over the axial length of the shaft fitting part 95b.

  34 and 35 show the first embodiment, FIG. 34 is a front view of the shaft 23-4 of the fourth modification, FIG. 35 is a view showing the insulating shaft portion 95 ((a) is a front sectional view, b) is a side view).

  As shown in FIG. 34, the shaft 23-4 of the fourth modification includes a shaft main body portion 23 e and an insulating shaft portion 95. The recessed portion 95h of the insulating shaft portion 95 is inserted into the shaft main body small diameter portion 23g at the opposite end of the shaft main body portion 23e. At this stage, the shaft main body portion 23e and the insulating shaft portion 95 are not fixed. In the subsequent process, the resin portion 24 is integrated.

  As shown in FIG. 35A, the insulating shaft portion 95 has a substantially cylindrical shape as a whole. The insulating shaft portion 95 has a substantially cylindrical shaft fitting portion 95b formed at an end portion on the shaft main body portion 23e side, and includes a concave portion 95h opened on the shaft main body portion 23e side inside the shaft fitting portion 95b.

  A bearing fitting portion 95a into which the anti-load-side rolling bearing 21b is fitted is connected to the shaft fitting portion 95b through a step 95j (see FIG. 35A). The bearing fitting portion 95a is thinner than the shaft fitting portion 95b by the level difference 95j. The shape of the bearing fitting portion 95a is substantially cylindrical.

  The outer peripheral surface of the shaft fitting part 95b is provided with a plurality of ribs 95g formed over the axial length of the shaft fitting part 95b. In the example of FIG. 35, eight ribs 95g are formed at substantially equal intervals (90 °) in the circumferential direction (see FIG. 35B).

  Each rib 95g extends to the central cylindrical portion 24g of the resin portion 24 in the radial direction. Accordingly, since the strength is ensured only by the insulating shaft portion 95, the quality can be stabilized and the quality can be improved by omitting external factors such as variations in molding conditions of the resin portion 24.

  Further, by fitting the rib 95g to the mold of the resin portion 24, the shaft receiving portion (not shown) of the mold for molding the resin portion 24 and the resin portion 24 can be kept coaxial so that Since the coaxiality of the bearing fitting portion 95a on the load side and the shaft main body portion 23e is ensured, the quality can be improved.

  Each rib 95g functions as a detent of the insulating shaft portion 95 after the insulating shaft portion 95 is integrated with the shaft main body portion 23e by the resin portion 24.

  Each rib 95g and step 95j function as a retaining member for the insulating shaft portion 95 after the insulating shaft portion 95 is integrated with the shaft main body portion 23e by the resin portion 24.

  FIG. 36 shows the first embodiment, and is a cross-sectional view of a rotor 20e of a fifth modification. The rotor 20e of Modification 5 includes a center hole 60j at the end of the insulating shaft 60 opposite to the load. Other than that, the configuration is the same as that of the rotor 20.

  The rotor 20e of the modified example 5 has a center hole 60j of the insulating shaft portion 60 of the shaft 23 when the shaft 23, the resin magnet 22 of the rotor and the resin magnet 25 for position detection are integrated (molded) by the resin portion 24. In addition, the metal mold (the upper mold) is fitted into the center hole 60j of the shaft 23 and provided with a projection that is coaxial with the upper mold and the lower mold shaft insertion portion, so that the mold is closed. When the protrusions are fitted into the center hole 60j of the shaft 23, the coaxiality between the resin magnet 22 of the rotor and the shaft 23 is improved.

  The center hole 60j may be formed at the load side end of the shaft body 23e.

  The electric motor 100 shown in FIG. 1 shows the one in which the mold stator 10 side is the load side and the bracket 30 side is the anti-load side, but the opposite may be possible.

  In addition, although a rotor resin magnet 22 formed by mixing a magnetic material with a thermoplastic resin in a permanent magnet such as the rotor 20 is used, other permanent magnets (rare earth magnets (neodymium, samarium iron), ferrites are used. Sintering etc.) may also be used.

  Similarly, other permanent magnets (rare earth magnets (neodymium, samarium iron), sintered ferrite, etc.) may be used for the position detecting resin magnet 25.

  As described above, when an electric motor is operated using an inverter, the carrier frequency of the inverter is set high for the purpose of reducing the noise of the electric motor generated due to the switching of the transistor in the power circuit. Yes. As the carrier frequency is set higher, the shaft voltage generated on the shaft of the motor based on the high frequency induction increases, and the potential difference existing between the inner ring and the outer ring of the rolling bearing supporting the shaft increases. This makes it easier for current to flow through the rolling bearing. The current flowing through the rolling bearings causes corrosion called electro-corrosion on the rolling surfaces of both the inner and outer ring raceways and the rolling elements (balls and rollers rolling between the inner and outer rings), thereby deteriorating the durability of the rolling bearings. .

  Therefore, the rotor 20 and the like of the present embodiment are particularly effective for reducing the shaft current when the electric motor 100 is operated using an inverter.

  FIG. 37 shows the first embodiment, and is a configuration diagram of a drive circuit 200 that drives the electric motor 100. As shown in FIG. 37, the inverter type drive circuit 200 includes a position detection circuit 110, a waveform generation circuit 120, a pre-driver circuit 130, and a power circuit 140.

  The position detection circuit 110 detects the magnetic pole of the position detection resin magnet 25 of the rotor 20 using the Hall IC 49b.

  The waveform generation circuit 120 generates a PWM (Pulse Width Modulation) signal for driving the inverter based on a speed command signal for instructing the rotation speed of the rotor 20 and a position detection signal from the position detection circuit 110, and a pre-driver Output to the circuit 130.

  The pre-driver circuit 130 outputs a transistor drive signal that drives the transistors 141 (six) of the power circuit 140.

  The power circuit 140 includes a DC power supply input unit and an inverter output unit, and includes an arm in which a transistor 141 and a diode 142 are connected in parallel and further connected in series.

  Since the electric motor 100 has three phases, a three-arm inverter output unit is connected to each coil 42 (FIG. 1). A 140V or 280V DC power source +, − obtained by rectifying AC 100V or 200V of commercial power is connected to the DC power source input unit.

  When the speed command signal is input to the drive circuit 200, the waveform generation circuit 120 sets the energization timing to each of the three-phase coils 42 according to the position detection signal and generates a PWM signal according to the input of the speed command signal. The pre-driver circuit 130 that outputs the PWM signal drives the transistor 141 in the power circuit 140.

  The inverter output unit drives the transistor 141 to apply a voltage to the coil 42, a current flows through the coil 42, torque is generated, and the rotor 20 rotates. It becomes the rotational speed of the electric motor 100 according to a speed command signal. The motor 100 is also stopped by a speed command signal.

FIG. 38 is a diagram illustrating the first embodiment, and is a diagram illustrating a manufacturing process of the rotor 20. The manufacturing process of the rotor 20 will be described with reference to FIG.
(1) Forming and demagnetizing the resin magnet 25 for position detection and the resin magnet 22 of the rotor. The shaft body 23e is processed and the insulating shaft 60 is molded (step 1).
(2) The position detection resin magnet 25 is set in the lower mold with the end portion having the step 25b facing downward, and the inner diameter pressing portion provided in the lower mold holds the inner diameter of the position detection resin magnet 25 (step 2). ).
(3) The positioning projection 22c of the resin magnet 22 of the rotor is fitted into the positioning projection insertion portion provided in the lower mold and set in the lower mold (step 3).
(4) The shaft 23 into which the insulating shaft 60 is inserted is set in the lower die, and the die 22 is clamped so that the notch 22a of the resin magnet 22 of the rotor is pressed by the notch holding portion of the upper die (step 4). .
(5) Resin (resin portion 24) is molded (step 5). When the resin magnet 22 of the rotor, the resin magnet 25 for position detection, and the shaft 23 are integrally formed by the resin portion 24, the insulating shaft portion 60 is interposed between the shaft 23 and the anti-load-side rolling bearing 21b. Is integrally molded.
(6) Magnetization of the resin magnet 22 of the rotor and the resin magnet 25 for position detection is performed (step 6).
(7) The load-side rolling bearing 21a and the anti-load-side rolling bearing 21b are assembled to the shaft 23 (step 7).

  According to the manufacturing process described above, when the resin magnet 22 of the rotor, the shaft 23, and the position detection resin magnet 25 are integrated with the resin (resin portion 24), all the parts are set in the mold and the resin. Since the molding is performed, the cost of the rotor 20 can be reduced by reducing the work process.

  Further, the pedestal 22b of the rotor resin magnet 22 enables the position detection resin magnet 25 to be separated from the end surface of the rotor resin magnet 22, and the thickness of the position detection resin magnet 25 is minimized and arbitrary. The cost can be reduced by filling a thermoplastic resin that is cheaper than the resin magnet 22 of the rotor.

  Further, since the position detecting resin magnet 25 is symmetrical in the thickness direction, it can be set in the mold without matching the orientation.

  In addition, since the portion through which the outer diameter passes when setting the lower mold position detection resin magnet 25 is tapered (tapered portion 24b of the resin portion 24), the lower die position detecting resin magnet 25 is set without being caught by the lower die. Therefore, the cost can be reduced with the improvement of productivity by simplifying the work process.

  Further, when the position detecting resin magnet 25 is set in the lower mold, the inner diameter is held by the inner diameter pressing portion provided in the lower mold, thereby ensuring the accuracy of the coaxiality between the shaft 23 and the resin magnet 22 of the rotor. Is done.

  Further, the notch holding portion provided in the upper mold presses the notch 22a provided in the inner diameter of the resin magnet 22 of the rotor, so that the accuracy of the coaxiality between the shaft 23 and the resin magnet 22 of the rotor is ensured. .

  As described above, in the present embodiment, the insulating shaft portion 60 is interposed between the anti-load-side rolling bearing 21b supported by the metal (conductive) bracket 30 and the shaft main body portion 23e, The insulating shaft part 60 is integrated with the resin part 24. The insulating shaft portion 60 insulates the anti-load side rolling bearing 21b from the shaft body 23e and suppresses the shaft current, thereby suppressing the occurrence of electrolytic corrosion on the load side and the anti-load side rolling bearing 21b. it can. However, the same effect can be obtained by integrating the ring-shaped position detecting resin magnet 25 with the resin portion 24 together with the shaft 23 and the resin magnet 22 of the ring-shaped rotor.

  Further, by providing a stepped portion 24e between the central cylindrical portion 24g of the resin portion 24 formed on the outer periphery of the shaft main body portion 23e and the bearing contact surface 24d, the shaft 23, the resin magnet 22 of the rotor, and the position are provided. When the detection resin magnet 25 is integrally formed of resin, when the bearing contact surface 24d of the central cylindrical portion 24g of the resin portion 24 is formed of ileco, the step portion 24e is formed of the eleco. Therefore, since the mating surface of the mold is the anti-load side end surface 24h of the central cylinder portion 24g, the anti-load side rolling bearing 21b is the anti-load that becomes the mating surface of the mold even if burrs occur on the mating surface of the mold. Since the stepped portion 24e is separated from the side end face 24h, the burr does not contact the anti-load side rolling bearing 21b. Therefore, there is little possibility of adversely affecting the anti-load side rolling bearing 21b.

  Further, when the rotor 20 receives a thermal shock, the central cylindrical portion 24g of the resin portion 24 may break, but a stepped portion 24e is provided in the central cylindrical portion 24g, and the radial direction of the central cylindrical portion 24g between the stepped portions 24e. Can be dealt with by increasing the thickness.

  Further, when the insulating shaft portion 60 is integrated by the resin portion 24, the central cylindrical portion 24g covers and integrates the convex portion 60g near the end surface 60d of the insulating shaft portion 60, so that the axial direction of the insulating shaft portion 60 and Circumferential movement can be suppressed.

  Further, when the convex portion 60g of the insulating shaft portion 60 is embedded in the central cylindrical portion 24g of the resin portion 24 formed on the outer periphery of the shaft main body portion 23e, the outer peripheral surface 60a- of the large diameter portion 60a of the insulating shaft portion 60 is provided. 1, the convex portion 60g is made to reach the outer peripheral surface 60a-1 at an equal angle (α) from a predetermined vertex 60g-1 (end surface 60d), so that the central cylindrical portion of the resin portion 24 is between the convex portions 60g. Since it becomes a part of 24g, the thickness of the central cylinder part 24g of the resin part 24 in the vicinity of the end surface 60d of the insulating shaft part 60 can be secured.

  Further, by causing the convex portion 60g of the insulating shaft portion 60 to reach the outer peripheral surface 60a-1 of the large-diameter portion 60a of the insulating shaft portion 60 at a predetermined angle (β) with respect to the axial direction from the vertex 60g-1. Further, it is possible to ensure the thickness in the vicinity of the axial end surface of the central cylindrical portion 24g of the resin portion 24.

  Further, the convex portion 60g that prevents and prevents the insulating shaft portion 60 integrally formed with the resin portion 24 from being formed in a substantially triangular pyramid shape and has a vertex formed on the end surface 60d of the large-diameter portion 60a of the insulating shaft portion 60. Thus, the central cylindrical portion 24g of the resin portion 24 is formed in the vicinity of the convex portion 60g. Therefore, the outer diameter of the central cylinder part 24g of the resin part 24 can be reduced. Thereby, cost reduction and quality can be ensured.

  Further, when the resin injection port is provided in a portion embedded in the resin portion 24, the resin injection port is on the outer periphery of the large diameter portion 60a of the insulating shaft portion 60, and the gate cutting portion 60c remains as a projection (projection portion). The concerns are dispelled.

  Moreover, the quality can be improved by using a thermosetting resin having a high creep resistance as a material of the insulating shaft portion 60 and a BMC resin of a thermosetting resin having a linear expansion coefficient close to that of iron.

  Compared with the rotor 20, the rotor 20 a of the first modification can reduce the amount of cutting of the shaft body 23 e or the cutting process as much as possible, thereby reducing the cost.

  Compared with the rotor 20, the rotor 20b of the modified example 2 can reduce cost by not cutting the shaft main body portion 23e. Further, since the insulating shaft portion 80 is directly fitted on the outer periphery of the shaft main body portion 23e, it is easy to ensure the coaxiality between the bearing fitting portion 80a of the insulating shaft portion 80 and the outer periphery of the shaft main body portion 23e. Can be improved.

  In the rotor 20c of the third modification, the insulating shaft portion 90 can be easily assembled to the shaft main body portion 23e, and the cost can be reduced. Moreover, since the thickness of the central cylinder part 24g of the resin part 24 can be ensured with respect to the modified example 2, the cost can be reduced by suppressing the outer diameter of the central cylinder part 24g.

  As for the rotor 20d of the modification 4, each rib 95g is extended to the center cylinder part 24g of the resin part 24 in radial direction. Accordingly, since the strength is ensured only by the insulating shaft portion 95, the quality can be stabilized and the quality can be improved by omitting external factors such as variations in molding conditions of the resin portion 24. Further, by fitting the rib 95g to the mold of the resin portion 24, the shaft receiving portion (not shown) of the mold for molding the resin portion 24 and the resin portion 24 can be kept coaxial so that Since the coaxiality of the bearing fitting portion 95a on the load side and the shaft main body portion 23e is ensured, the quality can be improved.

  The rotor 20e of the modified example 5 has a center hole 60j of the insulating shaft portion 60 of the shaft 23 when the shaft 23, the resin magnet 22 of the rotor and the resin magnet 25 for position detection are integrated (molded) by the resin portion 24. In addition, the metal mold (the upper mold) is fitted into the center hole 60j of the shaft 23 and provided with a projection that is coaxial with the upper mold and the lower mold shaft insertion portion, so that the mold is closed. When the protrusions are fitted into the center hole 60j of the shaft 23, the coaxiality between the resin magnet 22 of the rotor and the shaft 23 is improved.

  In addition, when the motor is operated using an inverter, the carrier frequency of the inverter is set higher for the purpose of reducing the noise of the motor. However, as the carrier frequency is set higher, the shaft of the motor is increased. In addition, the shaft voltage generated based on the high-frequency induction increases, and the potential difference existing between the inner ring and the outer ring of the rolling bearing supporting the shaft increases, so that the current flowing through the rolling bearing also increases. Therefore, the rotor 20 of the present embodiment is particularly effective for reducing the shaft current when the electric motor 100 is operated using an inverter. Here, the detection method is described using the Hall IC 49b which is a sensor for detecting the magnetic pole of the position detection resin magnet 25 of the rotor 20. However, the coil is not used without using the position detection resin magnet 25 and the Hall IC 49b. Needless to say, the sensorless driving method in which the flowing current is detected by a current detector (not shown) and the electric motor is driven by using a microcomputer or the like in the waveform generation circuit 120 has the same effect.

  38, when the resin magnet 22 of the rotor, the shaft 23 into which the insulating shaft portion 60 is inserted, and the position detection resin magnet 25 are integrated with the resin (resin portion 24). Since all the parts are set in a mold and resin-molded, the cost of the rotor 20 can be reduced by reducing the work process.

  Further, the pedestal 22b of the rotor resin magnet 22 enables the position detection resin magnet 25 to be separated from the end surface of the rotor resin magnet 22, and the thickness of the position detection resin magnet 25 is minimized and arbitrary. The cost can be reduced by filling a thermoplastic resin that is cheaper than the resin magnet 22 of the rotor.

  Further, since the position detecting resin magnet 25 is symmetrical in the thickness direction, it can be set in the mold without matching the orientation.

  In addition, since the portion through which the outer diameter passes when setting the lower mold position detection resin magnet 25 is tapered (tapered portion 24b of the resin portion 24), the lower die position detecting resin magnet 25 is set without being caught by the lower die. Therefore, the cost can be reduced with the improvement of productivity by simplifying the work process.

  Further, when the position detecting resin magnet 25 is set in the lower mold, the inner diameter is held by the inner diameter pressing portion provided in the lower mold, thereby ensuring the accuracy of the coaxiality between the shaft 23 and the resin magnet 22 of the rotor. Is done.

  Further, the notch holding portion provided in the upper mold presses the notch 22a provided in the inner diameter of the resin magnet 22 of the rotor, so that the accuracy of the coaxiality between the shaft 23 and the resin magnet 22 of the rotor is ensured. .

Embodiment 2. FIG.
FIG. 39 is a diagram showing the second embodiment and is a configuration diagram of the air conditioner 300.

  The air conditioner 300 includes an indoor unit 310 and an outdoor unit 320 connected to the indoor unit 310. The indoor unit 310 is equipped with an indoor unit blower (not shown), and the outdoor unit 320 is equipped with an outdoor unit blower 330.

  The outdoor unit blower 330 and the indoor unit blower include the electric motor 100 of the first embodiment as a drive source.

  The durability of the air conditioner 300 is improved by mounting the electric motor 100 of the first embodiment on the outdoor unit blower 330 and the indoor unit blower that are main components of the air conditioner 300.

  As an application example of the electric motor 100 of the present invention, the electric motor 100 can be used by being mounted on a ventilation fan, a home appliance, a machine tool, or the like.

  DESCRIPTION OF SYMBOLS 10 Mold stator, 10a Inner peripheral part, 11 Bearing support part, 20 Rotor, 20a Rotor, 20b Rotor, 20c Rotor, 20d Rotor, 20e Rotor, 21a Load side rolling bearing, 21a-1 Inner ring, 21a-2 outer ring, 21a-3 rolling element, 21b anti-load side rolling bearing, 21b-1 inner ring, 21b-2 outer ring, 21b-3 rolling element, 22 rotor resin magnet, 22a notch, 22b pedestal, 22c positioning Protrusion, 23 Shaft, 23-1 Shaft, 23-2 Shaft, 23-3 Shaft, 23-4 Shaft, 23a Knurl, 23e Shaft Main Body, 23f Anti-load-side End Surface, 23g Shaft Main Body Small Diameter, 23h Recess, 24 Resin part, 24a Inner diameter holding part, 24b Taper part, 24c Resin injection part, 24d Contact surface, 24e Stepped portion, 24f Fitting portion, 24g Center tube portion, 24h Anti-load side end surface, 24j Rib, 24k Cavity, 25 Position detection resin magnet, 25a Rib, 25b Step, 30 Bracket, 30a Bearing support portion 30b Press-fit part, 40 Stator, 41 Stator core, 42 Coil, 43 Insulating part, 44 terminal, 44a Power supply terminal, 44b Neutral point terminal, 45 Substrate, 46 Lead wire lead-out part, 47 Lead wire, 48 prism, 49a IC, 49b Hall IC, 50 Mold resin, 60 Insulating shaft part, 60a Large diameter part, 60a-1 Outer peripheral surface, 60b Small diameter part, 60c Gate cutting part, 60d End face, 60g Convex part, 60g-1 Vertex, 60j Center Hole, 70 Insulated shaft part, 70a Bearing fitting part, 70b Shaft fitting part, 70c Gate cutting part 70g rib, 70h recess, 70j step, 80 insulation shaft, 80a bearing fitting, 80b shaft fitting, 80c gate cutting part, 80g rib, 80h recess, 80j step, 90 insulation shaft, 90a bearing fitting 90c gate cutting part, 90c-1 step, 90h foot part, 90h-1 non-load side end part, 95 insulating shaft part, 95a bearing fitting part, 95b shaft fitting part, 95g rib, 95h concave part, 100 electric motor, 110 position detection circuit, 120 waveform generation circuit, 130 pre-driver circuit, 140 power circuit, 141 transistor, 142 diode, 200 drive circuit, 300 air conditioner, 310 indoor unit, 320 outdoor unit, 330 blower for outdoor unit.

Claims (13)

In the rotor of the electric motor in which the magnet and the shaft of the rotor are integrated by the resin portion, and rolling bearings are arranged on both axial end surfaces of the resin portion formed on the outer periphery of the shaft,
The shaft is
Forming a main body of the shaft, and supporting a load side rolling bearing;
An anti-load-side rolling bearing provided at an anti-load-side end of the shaft main body, and having an insulating shaft portion having an insulating property;
The rotor end of the electric motor according to claim 1, wherein an end surface on the anti-load side of the shaft main body is formed inside an end surface on the anti-load side axial direction of the resin portion. The insulating shaft portion includes a bearing fitting portion that supports the anti-load side rolling bearing, and a protruding portion that protrudes from the bearing fitting portion toward the shaft main body portion, and the anti-load of the shaft main body portion. The projecting portion of the insulating shaft portion is fitted into the recess formed in the side end portion,
Further, the insulating shaft portion includes a plurality of convex portions formed at substantially equal intervals in the circumferential direction on the outer peripheral surface near the protruding portion side end surface of the bearing fitting portion, and having apexes near the end surface. The rotor of the electric motor according to claim 1. The convex portion of the insulating shaft portion is
1stly, let the position away from the outer peripheral surface of the said bearing fitting part of the said insulation shaft part the predetermined distance be the said vertex, and the line which connects the center of the outer periphery circle | round | yen of the said bearing fitting part of the said insulation shaft part with the said vertex In contrast, it extends to the outer peripheral surface at substantially equal angles on both sides,
2ndly, it is the structure which faces the said outer peripheral surface of the said bearing fitting part of the said insulation shaft part in the axial direction at a predetermined angle from the said vertex, The rotor of the motor of Claim 2 characterized by the above-mentioned. The shaft main body has a protruding portion that protrudes in the axial direction at the opposite end portion on the load side,
The insulating shaft portion includes a bearing fitting portion that supports the anti-load-side rolling bearing, and a shaft fitting portion that has a recessed portion that opens to the load side inside the load-side end portion of the bearing fitting portion. Prepared,
The protruding portion of the shaft main body portion is fitted into the concave portion of the shaft fitting portion of the insulating shaft portion,
Further, the insulating shaft portion includes a plurality of ribs extending a predetermined length from the step between the shaft fitting portion and the bearing fitting portion toward the outer peripheral surface on the bearing fitting portion side. The rotor of the electric motor according to claim 1, wherein the rotor is an electric motor. The insulating shaft portion includes a bearing fitting portion that supports the anti-load-side rolling bearing, and a shaft fitting portion that has a recessed portion that opens to the load side inside the load-side end portion of the bearing fitting portion. Prepared,
The opposite end portion of the shaft main body portion is fitted into the concave portion of the shaft fitting portion of the insulating shaft portion,
Further, the insulating shaft portion includes a plurality of ribs extending a predetermined length from the step between the shaft fitting portion and the bearing fitting portion toward the outer peripheral surface on the bearing fitting portion side. The rotor of the electric motor according to claim 1, wherein the rotor is an electric motor. The insulating shaft portion is fitted to a bearing fitting portion that supports the anti-load side rolling bearing, a load-side end portion of the bearing fitting portion, and an outer peripheral surface of the anti-load side end portion of the shaft main body portion. A plurality of feet, and
2. The electric motor rotor according to claim 1, wherein an end of the foot on the side opposite to the load extends in a tapered manner on an outer peripheral surface of the bearing fitting portion at a predetermined angle. The insulating shaft portion includes a bearing fitting portion that supports the anti-load-side rolling bearing, and a shaft fitting portion that has a recessed portion that opens to the load side inside the load-side end portion of the bearing fitting portion. Prepared,
The opposite end portion of the shaft main body portion is fitted into the concave portion of the shaft fitting portion of the insulating shaft portion,
2. The electric motor according to claim 1, wherein the insulating shaft portion includes a plurality of ribs extending on an outer peripheral surface of the shaft fitting portion to an outer periphery of the resin portion formed on the outer peripheral surface of the shaft. Rotor.   The rotor of the electric motor according to any one of claims 1 to 7, wherein a material of the insulating shaft portion is a resin material having a linear expansion coefficient substantially equal to that of iron.   9. The rotor of an electric motor according to claim 8, wherein the material of the insulating shaft portion is a BMC (bulk molding compound) resin of a thermosetting resin.   An electric motor using the rotor of the electric motor according to claim 1. A position detection circuit for detecting a magnetic pole of the rotor by a position detection element;
A waveform generation circuit for generating a PWM (Pulse Width Modulation) signal for driving the inverter based on a speed command signal for instructing the rotation speed of the rotor and a position detection signal from the position detection circuit;
A pre-driver circuit that generates a drive signal from the output of the waveform generation circuit;
11. The electric motor according to claim 10, further comprising an inverter type drive circuit comprising a power circuit having an arm in which a transistor and a diode are connected in parallel and these are connected in series.   An air conditioner using the electric motor according to claim 10 or 11 as an electric motor for a blower. In the method of manufacturing a rotor of an electric motor in which a magnet and a shaft of a rotor are integrated by a resin portion, and rolling bearings are arranged on both axial end surfaces of the resin portion formed on the outer periphery of the shaft,
A method for manufacturing a rotor of an electric motor, comprising: an insulating shaft portion having an insulating property between the shaft and the rolling bearing, wherein the insulating shaft portion is integrated and fixed by the resin portion.