JP5173636B2 - Rotating electric machine - Google Patents

Description

  The present invention relates to a rotating electrical machine, and more particularly, to a rotating electrical machine having a stator core configured by fastening a plurality of divided cores each having a coil wound around a tooth portion in an annular shape.

  Conventionally, a hybrid vehicle that can use both an engine and a motor as a driving force source for wheels is known. In a hybrid vehicle, a three-phase AC permanent magnet type motor is generally used. This three-phase AC permanent magnet type motor has a rotor and a stator. The rotor or rotor has a substantially columnar shape with a permanent magnet fixed on the outer peripheral surface or in the vicinity thereof, and is supported so as to be rotatable about rotation shafts that project from both axial end surfaces.

  The stator or the stator includes a stator core made of, for example, an electromagnetic steel material that forms an annular shape disposed on the outer periphery of the rotor. The stator core has a teeth portion made of an electromagnetic steel material that is evenly arranged in the circumferential direction and that protrudes radially inward. Each of these teeth is wound with a coil around which a conductive wire such as an enamel wire is wound. By applying a three-phase AC voltage to these coils, a magnetic field with varying strength and magnetic poles is formed so as to rotate in the circumferential direction inside the stator core, and the rotor including the permanent magnet is driven to rotate by the action of this magnetic field. It is like that.

  Further, the stator core is not integrally molded, and a type in which a plurality of divided cores each having a tooth portion are assembled in an annular shape and fastened using a fastening member is known. In such a split core type stator core, each split core can be manufactured relatively easily and accurately as compared to the integral molding type, and a stator core can be configured by assembling a split core in which a coil is wound around a tooth portion in advance. There is an advantage that coil winding work is also easy.

  In the motor composed of the rotor and the stator, when a current flows through the coil of the stator core, the coil generates heat, thereby increasing the temperature of the stator core. Due to this temperature rise, there is a problem that the magnetic flux density passing through the inside of the stator core is reduced and the magnetic field strength is lowered, and the operating efficiency of the motor is lowered. Therefore, in order to maintain and improve the operation efficiency of the motor, it is important how to efficiently dissipate heat generated by energization of the coil to the outside of the motor.

Here, in Patent Document 1, a plurality of divided pieces 12C are arranged in an annular shape in the circumferential direction, and the divided pieces 12C are clamped and held from the outside in the radial direction by a cylindrical annular member 18 arranged on the outer periphery thereof. Thus, a rotating electrical machine is described in which a stator core 12 is configured, and a cylindrical case 20 is fixed to the outer periphery of the stator core 12 via a holding member 30 made of, for example, resin.

  In Patent Document 2, a thread groove is formed on the outer peripheral surface of the split core 12 so that a male screw is formed on the outer peripheral surface of the annular ring when the plurality of split cores 12 are arranged in an annular shape. An internal thread is formed on the inner surface of the cylindrical housing 11 for tightening and holding the divided cores 12 arranged in an annular shape from the outside. The divided housings 12 are divided into two parts. A rotating electrical machine is described in which each divided core 12 is fastened by being screwed from a direction opposite to the outer peripheral male screw of the core 12.

  Patent Document 3 discloses a cylindrical housing 2 in which a plurality of recesses 3c extending in the axial direction are arranged side by side in the circumferential direction on the outer circumferential surface of a ring-shaped stator 3 and fitted to the outer circumference of the stator 3. A plurality of convex portions 2c extending in the axial direction are arranged in the circumferential direction on the inner peripheral surface, and the housing 2 is sintered on the outer peripheral portion of the stator 3 so that the concave portions 3c and the convex 2c portions are engaged with each other. A motor to be fitted and fixed is described.

  Patent Document 4 describes a rotating electrical machine including a stator core in which heat radiation concave portions 27 and 37 and heat radiation convex portions 28 and 38 are alternately formed in the axial direction and the circumferential direction.

JP 2007-49838 A JP 2007-252040 A JP 2007-259560 A JP 2006-14463 A

  In the rotating electric machine of Patent Document 1, since a resin-made holding member is interposed between the split core type stator core and the motor case, heat is transferred from the stator core to the motor case by the holding member. Will be disturbed.

  In addition, the rotating electrical machine of Patent Document 2 described above uses a screw formed on the outer peripheral surface of each divided core and the inner surface of the housing when the plurality of divided cores are fastened in an annular shape by a cylindrical housing. The housing is assembled, but no consideration is given to heat radiation from a case member provided on the outer periphery of the housing to the outside of the motor.

  Furthermore, in the motor of Patent Document 3, the heat transfer area is obtained by providing the outer peripheral surface of the integrally molded annular stator and the inner peripheral surface of the cylindrical housing disposed on the outer periphery thereof so as to engage with each other. However, if the concave portion is formed in a cylindrical portion connecting the teeth portions in an integrally molded type stator, the cross-sectional area of the magnetic path is reduced. is there.

  Furthermore, in the rotating electrical machine of Patent Document 4, by forming a large number of heat radiation recesses and heat radiation recesses on the outer periphery of the stator core so as to appear alternately in the axial direction and the circumferential direction, the outer peripheral area that becomes the heat dissipation surface of the stator core is reduced. Although increased, the outer periphery of the stator core is disposed in a non-contact manner with respect to the motor case (see FIG. 1), so there is a difficulty in improving the heat dissipation efficiency to the outside of the motor.

  An object of the present invention is to provide a rotating electrical machine having a split core type stator core that can efficiently dissipate heat transferred from the coil to the stator core to the outside of the motor.

A rotating electrical machine according to the present invention includes a plurality of divided cores in which a coil is wound around a tooth portion, and a cylindrical fastening member that fastens from the outer periphery in a state where the divided cores are arranged in an annular shape and fastens each divided core. And a heat dissipating member that is disposed in contact with the outer periphery of the fastening member and dissipates heat transmitted from the fastening member to the outside, and the stator core is provided at a contact portion between the fastening member and the heat dissipating member. The heat transfer section is formed of a plurality of ridges and grooves that extend in the circumferential direction perpendicular to the axial direction of the two and engage and contact each other.

  According to the rotating electrical machine according to the present invention, the stator core, which is formed by fastening a plurality of split cores in an annular shape with a fastening member, is fitted to the contact portion between the fastening member and the heat dissipating member arranged in contact with the outer periphery thereof. By forming the heat transfer part consisting of the projecting ridge and the groove part, the heat transfer area between the fastening member and the heat radiating member is increased, and the heat transfer efficiency from the stator core to the heat radiating member is improved. Heat can be effectively radiated to the outside of the motor via the heat radiating member.

  Embodiments according to the present invention will be described below in detail with reference to the accompanying drawings. In this description, specific shapes, materials, numerical values, directions, and the like are examples for facilitating the understanding of the present invention, and can be appropriately changed according to the application, purpose, specification, and the like.

  FIG. 1 is a plan view of a stator core 10 constituting a rotating electrical machine 1 according to an embodiment of the present invention, FIG. 2 is a side view of the stator core 10, and FIG. 3 is a perspective view of a split core 12 constituting the stator core 10. The stator core 10 is made of, for example, an electromagnetic steel material, and is divided into a plurality of (12 in the example of FIG. 1) divided cores 12 arranged in an annular shape, and the divided cores 12 are tightened inward in the radial direction. And a cylindrical ring member (fastening member) 14 for fastening the core 12. In the following description, the “axial direction” refers to a direction that coincides with or follows the central axis C of the annular stator core 10, and the “radial direction” refers to a direction orthogonal to the axial direction.

  As shown in FIG. 3, the split core 12 has a yoke portion 16 having a substantially trapezoidal axial upper and lower end surface, and the yoke portion 16 is integrated with the yoke portion 16. A substantially rectangular parallelepiped tooth portion 18 that is molded and protrudes radially inward, and a substantially rectangular flange portion 20 having a peripheral edge larger than the outer contour of the tooth portion 18 in the radially innermost portion of the tooth portion 18. Is integrally molded or fixed.

  A coil 22 is wound around the teeth portion 18 of the split core 12 by winding a conductive wire such as an enamel wire several times. Since the coils 22 are individually arranged for each of the divided cores 12 before the divided cores 12 are assembled into an annular shape, the coils 22 are compared with the case where the coils 22 are wound around the plurality of teeth portions of the integrally formed stator core later. Thus, there is an advantage that the coil 22 can be easily wound or arranged.

  Moreover, the flange part 20 provided in the edge part of the teeth part 18 has controlled that a coil moves to an axial direction inner side. However, the flange part 20 in the split core 12 is not essential and may be omitted.

  Further, in the split core 12, a resin insulating sheet 21 is interposed between the coil 22 wound around the tooth portion 18 and the yoke portion 16. Thereby, the insulation between the coil 22 and the yoke part 16 is made more reliable.

In a state in which a plurality of divided cores 12 each having a coil wound around each tooth portion 18 are arranged in an annular shape using a jig or an internal mold (not shown), a cylindrical ring member 14 is shrink-fitted on the outer periphery thereof. It is placed by the press-fitting, the stator core 10 is constructed. Thereafter, a cylindrical case member (heat radiating member) 24 made of metal is brought into contact with the outer periphery of the ring member 14 of the stator core 10 by a method such as shrink fitting. Details of the contact portion between the ring member 14 and the case member 24 will be described later.

  A rotor or rotor 26 is disposed inside the stator core 10. The rotor 26 has a substantially cylindrical shape having a diameter that does not contact the flange portion 20 of each divided core 12, and is disposed concentrically with the stator core 10. Further, the rotary shafts 28 are formed so as to protrude from both axial end surfaces of the rotor 26. Each rotary shaft 28 is rotatably supported by bearings fixed to motor end case members (not shown) that are respectively attached to both end portions of the case member 24 in the axial direction by bolts or the like. It can be rotated inside.

  In addition, although the permanent magnet is being fixed to the rotor 26, the state which the permanent magnet exposed to the rotor outer peripheral surface may be fixed, or it may be embed | buriedly fixed inside the rotor of outer peripheral surface vicinity. .

  As shown in FIG. 2, in the stator core 10, both end portions in the axial direction of each coil 22 constitute a coil end portion 23 that protrudes from the axial end portion of the ring member 14. An insulating resin molding 29 is applied to cover the coil end portion 23. The resin molding 29 is formed inside the ring member 14 so as to enter between the coils 22 of the divided cores 12, thereby ensuring insulation between the adjacent coils 22.

  4 shows the AA cross section in FIG. 1, but the resin molding 29 is not shown. The ring member 14 is formed of a metal material having good heat conductivity. The ring member 14 fastens the plurality of divided cores 12 and transmits heat generated when a current flows through the coil 22 from the divided cores 12 to the case member 24. It also has a function to The case member 24 is also formed of a metal material having good heat conductivity, and functions as a housing that houses the stator core 10 and also functions as a heat radiating member that radiates heat transmitted from the ring member 14 to the outside of the motor.

  A contact portion between the ring member 14 and the case member 24, that is, an outer peripheral surface of the ring member 14 and an inner peripheral surface of the case member 24, are formed with heat transfer portions 30 including protrusions and groove portions that are fitted and in contact with each other. . More specifically, a protrusion 32 having a substantially triangular cross section is formed on the outer peripheral surface of the ring member 14, and a groove 34 having a V-shaped cross section that substantially matches the protrusion is formed on the inner peripheral surface of the case member 24. Has been. However, if viewed in reverse, it may be seen that a groove portion having a V-shaped cross section is formed on the outer peripheral surface of the ring member 14 and a protrusion having a substantially triangular cross section is formed on the inner peripheral surface of the case member 24. it can.

  A large number of the protrusions 32 are formed adjacent to each other in the axial direction, and a large number of the groove portions 34 are formed adjacent to each other in the axial direction. The protrusion 32 and the groove 34 are fitted and brought into contact with each other to constitute the heat transfer section 30. Further, the ridge 32 and the groove 34 are formed to extend in a direction intersecting with the axial direction of the stator core 10 on the projection plane viewed from the side of the rotating electrical machine (arrow B direction). Furthermore, the protrusion 32 and the groove part 34 may be formed linearly on the projection surface or may be formed in a curved line.

  Here, the “intersecting direction” includes all directions other than the direction along the axial direction. Therefore, on the projection surface, the protrusion 32 and the groove 34 may be formed to extend in a direction orthogonal to the central axis C of the stator core 10, in other words, the protrusion 32 and the groove 34 in the circumferential direction. Alternatively, it may be stretched in a direction inclined with respect to a direction orthogonal to the central axis C. FIG. 5 is a partial plan view of the case member 24 as viewed from the inside. FIG. 5A shows the groove 34 (and the protrusion 32 fitted thereto) extending in a direction perpendicular to the central axis C direction. FIG. 5B illustrates a state in which the groove 34 (and the protrusion 32 fitted therein) is stretched and formed in a direction inclined with respect to the central axis C direction.

  Moreover, the said protrusion 32 and the groove part 34 may each be formed in multiple numbers independently, or may be formed as a screw thread and a screw groove connected to one by the spiral. In this way, if the protrusion 32 and the groove 34 are formed as screw parts that can be screwed together, the case member 24 is screwed from above in FIG. 4 when the case member 24 is attached to the stator core 10, and the ring member 14. The case member 24 is connected and fixed to the ring member 14, that is, the stator core 10 by tightening until it is in contact with the screwing portion 36 provided at the lower outer periphery of the ring member 14.

  Thus, according to the rotating electrical machine including the stator core 10 and the case member 24, the ring member 14 of the stator core 10 formed by fastening the plurality of divided cores 12 in an annular shape by the ring member 14 and the outer periphery thereof are arranged in contact with each other. The heat transfer portion 30 including the protrusions 32 and the groove portions 34 that are fitted and in contact with each other is formed at the contact portion between the ring member 14 and the case member 24. The area is increased and the efficiency of heat transfer from the stator core 10 to the case member 24 is improved, whereby heat can be effectively radiated to the outside of the motor via the case member 24.

  Further, if the heat transfer portion 30 including the protrusions 32 and the groove 34 is configured as a screw portion, the case member 24 is simply screwed and tightened to the stator core 10 without depending on methods such as shrink fitting, press fitting, and bolt fastening. On the other hand, it can be easily connected and fixed.

  In the above description, the protrusion 32 and the groove 34 that are fitted and contacted with each other are illustrated as being formed adjacent to each other without any gap in the axial direction, but are not limited thereto. The protrusion 32 and the groove part 34 may be formed with a space formed by a circumferential surface along the axial direction. Moreover, each cross-sectional shape of the protrusion 32 and the groove part 34 is not limited to a substantially triangular shape, and may be another shape such as a semicircular shape as long as the contact area is increased by being fitted to each other. Good.

  Next, a rotating electrical machine 2 according to another embodiment will be described with reference to FIG. In the rotating electrical machine of this another embodiment, only the configuration of the heat transfer portion that is a contact portion between the stator core 10 and the case member 24 is different from the rotating electrical machine 1 including the stator core 10 and the case member 24. Accordingly, the same components such as the stator core 10 and the case member 24 are denoted by the same reference numerals and redundant description will be omitted, and only the differences will be described.

  6 is a partially enlarged plan view of a region D in FIG. In this embodiment, the ridge 32 formed on the outer peripheral surface of the ring member 14 and the groove portion 34 formed on the inner peripheral surface of the case member 24 so as to fit and contact with the ridge 32 are axially, that is, the center of the stator core 10. It is stretched along the axis C direction. Further, a large number of the protrusions 32 and the groove portions 34 are formed over the entire circumferential direction regardless of the position of the teeth portion 18 of the split core 12. In this case, the case member 24 is fixed to the ring member 14 constituting the outer periphery of the stator core 10 by a method such as shrink fitting or press fitting.

  As described above, even when the protrusions 32 and the grooves 34 that are fitted and brought into contact with each other are formed to extend along the axial direction, it is possible to improve the motor heat dissipation efficiency by increasing the heat transfer area. Further, a heat transfer portion 30 including a protrusion 32 and a groove portion 34 that are fitted to each other at a contact portion between a ring member 14 that fastens the plurality of split cores 12 in an annular shape and a case member 24 that is disposed on the outer periphery thereof. Therefore, the formation of these protrusions or grooves does not reduce the cross-sectional area of the yoke portion 16 that becomes a magnetic path in the divided core 12, and therefore, a large number of the entire circumferential direction regardless of the position of the teeth portion 18. There is also an advantage that it can be formed.

  In addition, in the said another embodiment, although the protrusion 32 and the groove part 34 which are mutually fitted and contacted were illustrated as each adjoining without the clearance gap in the circumferential direction, it is limited to this. Instead, the protrusion 32 and the groove 34 may be formed with an appropriate interval formed by an outer peripheral surface along the circumferential direction. Moreover, each cross-sectional shape of the protrusion 32 and the groove part 34 is not limited to a substantially triangular shape, and may be another shape such as a semicircular shape as long as the contact area is increased by being fitted to each other. Good.

It is a top view of the stator core of the rotary electric machine which is one Embodiment of this invention. It is a side view of the stator core of FIG. It is an expansion perspective view of one division core which constitutes a stator core. It is the sectional view on the AA line in FIG. It is the fragmentary top view which looked at the case member from the inside. It is a fragmentary top view which shows the contact part of the ring member and case member in the rotary electric machine of another embodiment.

Explanation of symbols

  1, 2 Rotating electrical machine, 10 Stator core, 12 Split core, 14 Ring member, 16 Yoke part, 18 Teeth part, 20 Flange part, 21 Insulating sheet, 22 Coil, 23 Coil end part, 24 Case member, 26 Rotor, 28 Rotation Axis, 29 Insulating resin molding, 30 Heat transfer part, 32 Projection, 34 Groove part, 36 Screwing part, C Center axis.

Claims (1)

A stator core configured to include a plurality of split cores around which coils are wound around the teeth portion, and a cylindrical fastening member that fastens the split cores from the outer periphery in a state where the split cores are arranged in an annular shape. A heat dissipating member disposed in contact with the outer periphery of the fastening member and dissipating heat transmitted from the fastening member to the outside;
The contact portion between the fastening member and the heat radiating member is formed with a heat transfer portion including a plurality of protrusions and groove portions that extend in the circumferential direction orthogonal to the axial direction of the stator core and are in contact with each other. Rotating electric machine.

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