JP5005063B2 - 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 in order to solve the above-described problems. An insulating sleeve applied to a shaft that insulates between a rolling bearing and a shaft in order to suppress electric corrosion of the bearing. An object of the present invention is to provide an electric motor rotor that can be securely fixed by the method, an electric motor, a method for manufacturing the electric motor rotor, and an air conditioner.

The rotor of the electric motor according to the present invention is an electric motor rotor in which a magnet and a shaft of the rotor are integrated by a resin portion, and rolling bearings are disposed on both end surfaces in the axial direction of the resin portion formed on the outer periphery of the shaft. ,
An insulating sleeve provided between at least one of the rolling bearings and the shaft and integrated by the resin portion;
And a plurality of convex portions formed at substantially equal intervals in the circumferential direction in the vicinity of the end surface on the side embedded in the resin portion of the insulating sleeve and having apexes in the vicinity of the end surface.

  The rotor of the electric motor according to the present invention is provided with a plurality of convex portions formed at substantially equal intervals in the circumferential direction near the end surface on the side embedded in the resin portion of the insulating sleeve, and having apexes near the end surface. The insulating sleeve can be reliably fixed by a simple method, and the thickness of the resin portion in the vicinity of the convex portion can be ensured without increasing the outer diameter of the resin portion.

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 front view of a shaft 23; FIG. 5 shows the first embodiment, and is an enlarged cross-sectional view of an end portion on the counterload side of the rotor 20. FIG. 5 shows the first embodiment and shows the insulating sleeve 26 ((a) is a side view, (b) is a front view). FIG. 3 is a diagram showing the first embodiment, and is a perspective view showing an insulating sleeve 26; The B section enlarged view of FIG. FIG. 5 shows the first embodiment, and is an enlarged side view of a convex portion 26b viewed from the end face 26d side. The A section enlarged view of FIG.11 (b). FIG. 4 is a diagram showing the first embodiment, and is a perspective view showing a state immediately before an insulating sleeve 26 is inserted into a shaft 23; FIG. 4 is a diagram showing the first embodiment, and is a perspective view in which an insulating sleeve is inserted into a shaft. 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 cross-sectional view of a rotor 20b of a second modification. FIG. 5 shows the first embodiment, and is a front view of an insulating sleeve 26 used for the rotor 20b of the second modification. FIG. 5 shows the first embodiment, and is a cross-sectional view of a rotor 20c of a third modification. 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 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 21 a (an example of a rolling bearing) of the rotor 20 is pushed in until it comes into contact with the bearing support portion 11 at the axial end portion on the side opposite to the opening of the mold stator 10. At this time, the load-side rolling bearing 21 a 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.

  The rotor 20 has an anti-load-side rolling bearing 21b (an example of a rolling bearing) attached to an anti-load-side shaft 23 (right side in FIG. 1) (generally by press-fitting).

  Although details will be described later, an insulating sleeve 26 is provided between the anti-load side rolling bearing 21b and the anti-load side shaft 23.

  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 9 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 is a side view of the rotor 20-1 as viewed from the load side, and FIG. 9 is a front view of the shaft 23.

  As shown in FIGS. 6 and 7, the rotor 20 (or the rotor 20-1) includes a shaft 23 (see FIG. 9) provided with a knurl 23 a, a resin magnet 22 of a ring-shaped rotor (of the rotor). An example of a magnet), a ring-shaped position detection resin magnet 25 (an example of a position detection magnet), and a resin portion 24 that integrally molds these.

  The resin magnet 22 of the ring-shaped rotor, the shaft 23 (see also FIG. 9), and the position detection resin magnet 25 are integrated by a resin portion 24 injected by a vertical molding machine. At this time, the resin part 24 is formed on the outer periphery of the shaft 23, and a central cylinder part 24g (formed inside the rotor resin magnet 22), which will be described later, and the rotor resin magnet 22 are arranged in the central cylinder part 24g. And a plurality of axial ribs 24j (see FIG. 8) radially formed in the radial direction with the shaft 23 as a center. A cavity 24k (see FIG. 8) penetrating in the axial direction is formed between the ribs 24j.

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

  An anti-load-side rolling bearing 21b is attached to the non-load-side shaft 23 (right side in FIG. 6) (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 known rolling bearings, description thereof 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 shaft 23 via an insulating sleeve 26, an outer ring 21b-2 that is supported by the bearing support portion 30a of the bracket 30, and an inner ring 21b-1 and an outer ring 21b. -2 is provided with rolling elements 21b-3 that roll between -2. A ball or a roller is used for the rolling element 21b-3.

  In the present embodiment, an insulating sleeve 26 is interposed between the anti-load-side rolling bearing 21b supported by a metal (conductive) bracket 30 and the shaft 23, so that the insulating sleeve 26 becomes an insulating shaft current. It is characterized in that the occurrence of electrolytic corrosion of the anti-load side rolling bearing 21b is suppressed by suppressing.

  Further, an insulating sleeve 26 provided between the anti-load side rolling bearing 21b and the shaft 23 is inserted in the vicinity of the end of the anti-load side of the shaft 23. The shaft 23, the resin magnet 22 of the ring-shaped rotor, the ring The insulating sleeve 26 is also integrated when the position detecting resin magnet 25 is integrated by the resin portion 24.

  In the portion of the shaft 23 where the insulating sleeve 26 is assembled, the thickness of the insulating sleeve 26 is cut, and the outer diameter of the central portion 23e of the shaft 23 and the insulating sleeve 26 is substantially the same.

  As described above, since the insulating sleeve 26 inserted into the shaft 23 is integrated and fixed by the resin portion 24, the fixing of the insulating sleeve 26 becomes extremely simple, and the insulating sleeve 26 is securely fixed from the shaft 23. The risk of coming off is reduced.

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

  Since the shaft current flowing through the load-side rolling bearing 21a decreases as the shaft current flowing through the anti-load-side rolling bearing 21b decreases due to the insulating sleeve 26 provided between the anti-load-side rolling bearing 21b and the shaft 23, The shaft 23 may not be insulated.

  FIG. 10 is a diagram showing the first embodiment, and is an enlarged cross-sectional view of the end portion on the non-load side of the rotor 20. In FIG. 10, the diameter d <b> 2 of the anti-load side end portion 23 d of the shaft 23 where the anti-load side rolling bearing 21 b is held via the resin portion 24 is that the resin magnet 22 of the rotor is held via the resin portion 24. A step 23c is provided to be smaller than the diameter d1 of the central portion 23e.

  The dimension between the anti-load side end face 23f (axial end face) of the shaft 23 and the step 23c is longer than the thickness (axial length) of the anti-load side rolling bearing 21b. The non-load-side end surface 23f of the shaft 23 is exposed in the example of FIG.

  The resin portion 24 has a bearing abutment surface 24d that is positioned in the axial direction when the anti-load-side rolling bearing 21b is inserted into the anti-load-side end 23d of the shaft 23. The resin portion 24 is formed at the opposite end of the central cylinder portion 24g (resin portion) of the resin portion 24.

  The central cylindrical portion 24g of the resin portion 24 formed on the outer periphery with the knurled portion of the shaft 23 as the center in the axial direction has a stepped portion 24e between the outer peripheral portion of the central cylindrical portion 24g and the bearing contact surface 24d. Is provided.

  It is essential that the diameter of the stepped portion 24e is smaller than the inner diameter of the outer ring 21b-2 of the anti-load side rolling bearing 21b. In the rotor 20 shown in FIG. 6, the stepped portion 24e has a diameter that is substantially the same as or slightly smaller than the outer diameter 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 of the stepped portion 24e is made larger than the outer diameter of the inner ring 21b-1 of the anti-load side rolling bearing 21b, the portion larger than the outer diameter of the inner ring 21b-1 becomes the anti-load side rolling bearing 21b. Do not touch. Accordingly, the diameter of the stepped portion 24e is practically the same as or slightly smaller than the outer diameter 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.

  Since the diameter of the stepped portion 24e is smaller than the inner diameter 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 radial direction of the central cylindrical portion 24g between the stepped portions 24e. Can be made larger than the inner diameter of the outer rings 21a-2 and 21b-2.

  11 to 17 show the first embodiment, FIG. 11 is a view showing the insulating sleeve 26 ((a) is a side view, (b) is a front view), and FIG. 12 is a perspective view showing the insulating sleeve 26. 13 is an enlarged view of a portion B in FIG. 12, FIG. 14 is an enlarged side view of the convex portion 26b as viewed from the end face 26d side, FIG. 15 is an enlarged view of a portion A in FIG. FIG. 17 is a perspective view in which the insulating sleeve 26 is inserted into the shaft 23.

The insulating sleeve 26 will be described with reference to FIGS. As shown in the figure, the insulating sleeve 26 is substantially cylindrical. The insulating sleeve 26 includes a plurality of convex portions 26b having the following configuration at the end of the resin portion 24 on the central cylindrical portion 24g side.
(1) First, on the end surface 26d embedded in the resin portion 24 formed on the outer periphery of the shaft 23 of the insulating sleeve 26, first, the position of the end surface 26d at a predetermined distance away from the outer periphery is a vertex 26b- 1 with respect to a radius passing through the vertex 26b-1 (a line connecting the vertex 26b-1 and the center of the outer circumferential circle of the insulating sleeve 26), the intersection points a and a with the outer circumferential circle of the insulating sleeve 26 at equal angles (α) on both sides. It is a substantially triangular shape intersecting at b (see FIG. 14).
(2) Secondly, the shape on the inner side in the axial direction from the end surface 26d forms a convex portion 26b facing the outer peripheral surface 26a of the insulating sleeve 26 in the axial direction at a predetermined angle (β) from the vertex 26b-1. (See FIG. 15).
(3) As shown in FIG. 11A, the plurality of convex portions 26b are formed at substantially equal intervals in the circumferential direction. In the example of FIG. 11A, seven convex portions 26b are formed at intervals of approximately 45 °.

  The insulating sleeve 26 has a resin-injection gate cutting portion 26c having a predetermined width and extending in the axial direction at the time of resin molding in the vicinity of the end surface 26d. As shown in FIG. Each of the portions 26b is positioned at a substantially central portion of the two convex portions 26b at an interval of about 45 °.

  In short, the shape of the convex portion 26b is “substantially triangular pyramid”. One of the four corners of the triangular pyramid is the apex at the end face 26d, the two corners are located at the intersections a and b where the end face 26d intersects the outer circumference of the insulating sleeve 26, and the remaining one corner is the end face. It is located on the outer peripheral surface 26a at a predetermined distance in the axial direction from 26d.

  As shown in FIGS. 16 and 17, the insulating sleeve 26 is inserted into the anti-load side end 23 d of the shaft 23.

  The protrusion 26b of the insulating sleeve 26 shown in FIGS. 11 to 17 is an example, and the shape thereof is not limited to “substantially triangular pyramid”. The convex portion 26b has a vertex in the vicinity of the end surface 26d of the insulating sleeve 26, and any configuration may be used as long as the convex portion 26b faces the outer circumferential surface 26a for a while in the circumferential direction or the axial direction. And the outer peripheral surface of the convex part 26b may not be a plane, but a curved surface may be sufficient as it.

  When the insulating sleeve 26 is integrated by the resin portion 24, the central cylindrical portion 24g covers and integrates the convex portion 26b in the vicinity of the end face 26d of the insulating sleeve 26, so that the insulating sleeve 26 is moved in the axial direction and the circumferential direction. Suppressed.

  When the convex portion 26b of the insulating sleeve 26 is embedded in the central cylindrical portion 24g of the resin portion 24 formed on the outer periphery of the shaft 23, the convex portion 26b is predetermined (end surface 26d) with respect to the outer peripheral surface 26a of the insulating sleeve 26. Is made to reach the outer circumferential surface 26a from the vertex 26b-1 at an equal angle (α) (see FIG. 14). Thereby, since the space between the convex portions 26b 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 face 26d of the insulating sleeve 26 can be secured.

  Further, by causing the convex portion 26b of the insulating sleeve 26 to reach the outer peripheral surface 26a of the insulating sleeve 26 at a predetermined angle (β) from the vertex 26b-1 in the axial direction (see FIG. 15), the resin portion 24 is obtained. The wall thickness in the vicinity of the axial end surface of the central cylindrical portion 24g can be secured.

  By forming the convex part 26b that prevents the insulation sleeve 26 integrally formed with the resin part 24 from rotating and coming off as described above, the central cylindrical part 24g of the resin part 24 is formed in the vicinity of the convex part 26b. . 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.

  The electric motor 100 (including the rotor 20) is required to have thermal shock resistance. 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 central cylindrical part 24g of the resin part 24 needs to have a predetermined thickness. By forming the convex part 26b that prevents the insulation sleeve 26 integrally formed with the resin part 24 from rotating and coming off as described above, the thickness of the central cylindrical part 24g of the resin part 24 near the convex part 26b is increased. It can be ensured without increasing the outer diameter of the central cylindrical portion 24g.

  When the resin injection port is on the outer periphery of the insulating sleeve 26, if the gate cutting part 26c remains as a projection (protruding part), the rolling bearing inner diameter and the gate cutting part 26c come into contact with each other when the bearing (anti-load-side rolling bearing 21b) is inserted. As a result, unexpected stress is generated, and the gate cutting part 26c is cut, and it is expected that the quality deteriorates due to adhesion as dust.

  Further, when the resin injection port is provided on the surface opposite to the end surface 26 d provided with the convex portion 26 b of the insulating sleeve 26, when the resin magnet 22 of the rotor and the shaft 23 are integrally formed with the resin portion 24, the mold Since the gate cutting portion 26c of the resin injection port comes to the portion that comes into contact with the gate, if the gate cutting portion 26c remains as a projection (protruding portion), the surface is not secured, making it difficult to secure the dimensions during molding. Also, when the mold is tightened, the gate cutting part 26c of the resin injection port is crushed and adheres to the mold as dust, so that the gate cutting part 26c does not remain at the time of molding. Due to the difficulty in securing the dimensions, there is a concern about the deterioration of quality. Further, in the case where the resin inlet is provided on the surface of the end surface 26d provided with the convex portion 26b of the insulating sleeve 26 in contact with the shaft, the gate cutting portion 26c is convex (protruding portion) when the insulating sleeve 26 is installed on the shaft 23. If the surface remains, the surface is not secured, and it is difficult to secure the dimensions during molding.

  On the other hand, by providing the resin injection port in the portion embedded in the resin portion 24, the above-mentioned concern can be eliminated, and even if the gate cutting portion 26c becomes a convex portion or a concave portion, the resin is injected. As a result, the gate cutting portion 26c functions as a stopper for the insulating sleeve 26, so that the quality can be improved.

As the material of the insulating sleeve 26, it is preferable to use a resin material having substantially the same linear expansion coefficient as that of iron (the shaft 23). 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.

  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, the 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. In the present embodiment, the insulating sleeve 26 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.

  The thickness d (FIG. 11B) in the radial direction of the insulating sleeve 26 is, for example, 1 to 2 mm. However, it is not limited to this range.

  18A and 18B are views showing the resin magnet 22 of the rotor. FIG. 18A is a left side view, FIG. 18B is a cross-sectional view taken along the line CC of FIG. 18A, and FIG. is there. A configuration of the resin magnet 22 of the ring-shaped rotor will be described with reference to FIG. The rotor resin magnet 22 has an axial end of the inner diameter (on the right side in FIG. 18B) to ensure the coaxiality of 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. 18, the notches 22a are formed at eight locations at substantially equal intervals in the circumferential direction (FIG. 18 (c)).

  In addition, on the resin magnet 22 of the rotor, pedestals 22b for mounting the position detection resin magnet 25 are formed at substantially equal intervals in the circumferential direction on the end surface of the other axial end portion (left side in FIG. 18B). 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.

  The structure of the ring-shaped position detection resin magnet 25 will be described with reference to FIG. FIG. 19A is a left side view of the position detection resin magnet 25, FIG. 19B is a front view of the position detection resin magnet 25, and FIG. 19C is an enlarged view of a portion D of 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. 19, 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 rotor resin magnet 22 is formed by mixing a thermoplastic material with a magnetic material. As shown in FIG. 18, 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. 19, 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 the resin, on the steps 25b on both sides. 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. 20 is a diagram illustrating the first embodiment, and is a cross-sectional view of a rotor 20a of a first modification. A difference from the rotor 20 shown in FIG. 6 is that a center hole 23 b is formed at the end of the shaft 23 on the side opposite to the load.

  When the shaft 23, the rotor resin magnet 22 and the position detection resin magnet 25 are integrated (molded) by the resin portion 24, the center hole 23 b of the shaft 23 is inserted into the center hole of the mold (upper mold) shaft 23. 23b, and provided with a projection that is coaxial with the upper and lower mold shaft insertion portions, the projection fits into the center hole 23b of the shaft 23 when the mold is closed. The concentricity between the resin magnet 22 of the rotor and the shaft 23 is improved by being stuck.

  The center hole 23b may be formed at both ends of the shaft 23.

  FIG. 21 is a diagram showing the first embodiment, and is a cross-sectional view of a rotor 20b of a second modification. A difference from the rotor 20 shown in FIG. 6 is that an insulating sleeve 26 covers the entire anti-load side end 23 d of the shaft 23.

  FIG. 22 shows the first embodiment, and is a front view of the insulating sleeve 26 used in the rotor 20b of the second modification. As shown in FIG. 22, the insulating sleeve 26 has a cap shape in which one end in the axial direction is open and the other end is closed. Therefore, when the rotor 20 is molded by the resin portion 24, the closed end face 26e of the insulating sleeve 26 is pressed by the mold.

  The advantage of the insulating sleeve 26 shown in FIG. 22 is that the anti-load-side rolling bearing 21b is held by the diameter d2 (FIG. 10) of the anti-load-side end 23d of the shaft 23 held via the insulating sleeve 26, and the central cylindrical portion 24g. Even when the fitting shaft diameter d1 (FIG. 10) is the same and there is no step 23c (FIG. 9), when the insulating sleeve 26 is inserted into the shaft 23, the end surface of the shaft 23 on the non-load side end 23d is insulated. By pushing in until the end face 26e of the sleeve 26 comes into contact, the axial position of the insulating sleeve 26 with respect to the shaft 23 is determined. In addition, the thickness d in the radial direction of the insulating sleeve 26 is, for example, 1 to 1.5 mm. However, it is not limited to this range.

  6 and 20, when the shaft 23 has no step 23c (FIG. 9), when the insulation sleeve 26 is inserted into the shaft 23, the insulation sleeve 26 is positioned in the axial direction with respect to the shaft 23. difficult.

  FIG. 23 is a diagram showing the first embodiment, and is a cross-sectional view of a rotor 20c of a third modification. A difference from the rotor 20 shown in FIG. 21 is that a center hole 23 b is formed at the end of the shaft 23 opposite to the load.

  When the shaft 23 into which the insulating sleeve 26 is inserted, the rotor resin magnet 22 and the position detection resin magnet 25 are integrated (molded) by the resin portion 24, a mold (upper mold) is inserted into the center hole 23b of the shaft 23. ) And a projection that fits in the center hole 23b of the shaft 23 and is coaxial with the upper and lower mold shaft insertion portions, so that when the mold is closed, the projection becomes the shaft. By fitting into the center hole 23b of the rotor 23, the coaxiality between the resin magnet 22 of the rotor and the shaft 23 is improved.

  FIG. 24 is a diagram illustrating the first embodiment, and is a cross-sectional view of a rotor 20d according to a fourth modification. 6 differs from the rotor 20 shown in FIG. 6 in that an insulating sleeve 26 is interposed between the load-side rolling bearing 21a and the shaft 23 to insulate them.

  With the configuration as shown in FIG. 24, the shaft current in the load-side rolling bearing 21a can be further reduced. Furthermore, the shaft current of the motor other than the mold stator 10, for example, using a steel plate frame for the outer shell and using a metal bracket on the load side and the non-load side can be reduced.

  The rotor 20d shown in FIG. 24 has the same configuration as the anti-load side end 23d of the shaft 23 as shown in FIG. 6, but may have other configurations shown in FIGS.

  In addition, although the electric motor 100 shown in FIG. 1 showed what the mold stator 10 side becomes a load side and the bracket 30 side becomes an anti-load side, the reverse may be sufficient.

  The rotor 20 shown in FIGS. 6, 20, 21, 23, and 24 uses a rotor resin magnet 22 formed by mixing a permanent magnet with a thermoplastic resin and a magnetic material. Other permanent magnets (rare earth magnets (neodymium, samarium iron), ferrite sintered, etc.) may 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 of the present embodiment is particularly effective for reducing the shaft current when the electric motor 100 is operated using an inverter.

  FIG. 25 is a diagram illustrating the first embodiment, and is a configuration diagram of a drive circuit 200 that drives the electric motor 100. As shown in FIG. 25, 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. 26 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 23 is processed and the insulating sleeve 26 is formed (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 sleeve 26 is inserted is set in the lower mold, and the mold 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 mold (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 shaft 23 and at least one of the load side rolling bearing 21a or the anti-load side rolling bearing 21b are interposed between them. Then, integral molding is performed so that the insulating sleeve 26 is interposed.
(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 sleeve 26 is interposed between the anti-load-side rolling bearing 21b supported by the metal (conductive) bracket 30 and the shaft 23, and this insulating sleeve. 26 is integrated with the resin portion 24. By the insulating sleeve 26, the anti-load side rolling bearing 21b and the shaft 23 are insulated from each other and the shaft current is suppressed, so that the occurrence of electrolytic corrosion on the load side and the anti-load side rolling bearing 21b can be suppressed. 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 step portion 24e between the central cylindrical portion 24g of the resin portion 24 formed on the outer periphery of the central portion 23e of the shaft 23 and the bearing contact surface 24d, the shaft 23 and the resin magnet 22 of the rotor are provided. Further, when the position detecting 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 sleeve 26 is integrated by the resin portion 24, the central cylindrical portion 24g covers and integrates the convex portion 26b in the vicinity of the end surface 26d of the insulating sleeve 26, so that the axial direction and the circumferential direction of the insulating sleeve 26 are integrated. Movement can be suppressed.

  Further, when the convex portion 26b of the insulating sleeve 26 is embedded in the central cylindrical portion 24g of the resin portion 24 formed on the outer periphery of the shaft 23, the convex portion 26b is set to a predetermined (end surface) with respect to the outer peripheral surface 26a of the insulating sleeve 26. 26d) by reaching the outer peripheral surface 26a from the vertex 26b-1 at an equal angle (α), the space between the convex portions 26b becomes a part of the central cylindrical portion 24g of the resin portion 24. Therefore, the end surface 26d of the insulating sleeve 26 The thickness of the central cylinder part 24g of the resin part 24 in the vicinity can be secured.

  Further, by causing the convex portion 26b of the insulating sleeve 26 to reach the outer peripheral surface 26a of the insulating sleeve 26 at a predetermined angle (β) with respect to the axial direction from the apex 26b-1, the central cylindrical portion 24g of the resin portion 24 is obtained. It is possible to secure a wall thickness in the vicinity of the end face in the axial direction.

  In addition, the convex portion 26b that prevents and prevents the insulating sleeve 26 integrally formed with the resin portion 24 from being formed in a substantially triangular pyramid shape and has an apex formed on the end surface 26d of the insulating sleeve 26, so that the convex portion 26b is located near the convex portion 26b. A central cylindrical portion 24g of the resin portion 24 is formed. 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, by providing the resin injection port in the portion embedded in the resin part 24, the concern that the resin injection port is on the outer periphery of the insulating sleeve 26 and the gate cutting part 26c remains as a protrusion (protrusion) is eliminated. .

  Further, the quality of the insulating sleeve 26 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.

  Further, as in the rotor 20a of the first modification shown in FIG. 20, the center hole 23b is formed in the end portion on the opposite side of the shaft 23, so that the shaft 23, the resin magnet 22 of the rotor, and the position detection resin magnet are formed. When integrally molding 25 with a resin, a projection that fits into the center hole 23b of the shaft 23 is secured in the center hole 23b of the shaft 23 with the shaft insertion portion provided in the mold (upper mold and lower mold). By fitting, the shaft 23 can be held in a state where the coaxiality is secured, and the coaxiality between the resin magnet 22 of the rotor and the shaft 23 is improved.

  Further, as in the rotor 20b of the modified example 2 shown in FIG. 21, the insulating sleeve 26 may cover the entire anti-load side end 23d of the shaft 23, and the insulating sleeve 26 has one end in the axial direction. Since the cap is open and the other end is closed, the end surface 20c of the insulating sleeve 26 is pressed by a mold during molding by the resin portion 24 of the rotor 20.

  22, the insulating sleeve 26 covers the entire anti-load side end portion 23d of the shaft 23 and a center hole 23b is formed at the anti-load side end portion of the shaft 23. Thus, when the shaft 23 into which the insulating sleeve 26 is inserted, the resin magnet 22 of the rotor, and the resin magnet 25 for position detection are integrated (molded) by the resin portion 24, a mold is formed in the center hole 23b of the shaft 23. By providing a protrusion that fits into the center hole of the shaft of the (upper mold) and that is coaxial with the upper mold and the lower mold shaft insertion portion, the protrusion is formed when the mold is closed. By fitting in the center hole of the shaft, the coaxiality between the resin magnet 22 of the rotor and the shaft 23 is improved.

  Further, as in the rotor 20d of the fourth modification shown in FIG. 24, an insulating sleeve 26 is interposed between the load side rolling bearing 21a and the shaft 23 so as to insulate the load side rolling bearing 21a. And the shaft current in the anti-load side rolling bearing 21a can be further reduced. Furthermore, the shaft current of the motor other than the mold stator 10, for example, using a steel plate frame for the outer shell and using a metal bracket on the load side and the non-load side can be reduced.

  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.

  Further, according to the manufacturing process shown in FIG. 26, when the resin magnet 22 of the rotor, the shaft 23 into which the insulating sleeve 26 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. 27 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, 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, 23a Knurl, 23b Center hole, 23c Step, 23d Anti-load side End part, 23e center part, 23f anti-load side end face, 24 resin part, 24a inner diameter pressing part, 24b taper part, 24c resin injection part, 24d contact surface, 24e step part, 24f fitting part, 24g center tube part, 24h Anti-load side end face, 25 Position detection resin magnet, 25a Rib, 25b Step, 26 Insulation thread 26a, outer peripheral surface, 26b convex portion, 26b-1 apex, 26c gate cutting portion, 26d end surface, 26e end surface, 30 bracket, 30a bearing support portion, 30b press-fit portion, 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 Square pillar, 49a IC, 49b Hall IC, 50 Mold resin, 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 (10)

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,
An insulating sleeve provided between at least one of the rolling bearings and the shaft and integrated by the resin portion;
A rotation of the electric motor comprising: a plurality of convex portions formed at substantially equal intervals in the circumferential direction near the end surface of the insulating sleeve on the side embedded in the resin portion and having apexes near the end surface Child. The convex portion of the insulating sleeve is
First, a position separated from the outer peripheral surface of the insulating sleeve by a predetermined distance is the apex, and extends to the outer peripheral surface at substantially equal angles on both sides with respect to a line connecting the apex and the center of the outer peripheral circle of the insulating sleeve. ,
2ndly, it is the structure which faces the said outer peripheral surface of the said insulation sleeve in the axial direction at a predetermined angle from the said vertex, The rotor of the motor of Claim 1 characterized by the above-mentioned.   The insulating sleeve includes a resin injection port having a predetermined width and extending in the axial direction on an outer periphery of the end surface side on the side including the convex portion, and a gate cutting portion of the resin injection port is also embedded in the resin portion. The rotor of the electric motor according to claim 2, wherein the rotor is stopped.   4. The rotor of an electric motor according to claim 1, wherein the material of the insulating sleeve is a resin material having a coefficient of linear expansion substantially the same as that of iron. 5. The rotor of an electric motor according to claim 4, wherein the material of the insulating sleeve is BMC (bulk molding compound) resin of thermosetting resin.   The portion of the shaft to which the insulating sleeve is assembled is cut by the thickness of the insulating sleeve, and the outer diameter of the central portion of the shaft and the insulating sleeve is substantially the same. The rotor of the electric motor according to any one of 5.   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;
8. The electric motor according to claim 7, 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 7 or 8 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, wherein an insulating sleeve is inserted between the shaft and the rolling bearing, and the insulating sleeve is integrated and fixed by the resin portion.