JP2019041518A - Rotary electric machine - Google Patents

Abstract

To provide a rotary electric machine capable of reducing electric noise.SOLUTION: A blower motor 10 includes a stator 12 in which a coil 22 is wound around a stator core 20, a circuit board 48 constituting a part of a control section 16 for controlling energization to the core 22, and a rotor 14 rotating by generation of a magnetic field by the stator 12. The blower motor 10 includes a holder 18 that is formed using a resin material and to which the stator 12 and the circuit board 48 are fixed, and a fixing member (bolt 28 and bag nut 60) which is formed using a conductive material, fixes at least one of the stator 12 and the circuit board 48 to the holder, and electrically connects the stator core 20 and the circuit board 48.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a rotating electrical machine.

  Patent Document 1 listed below discloses a rotating electrical machine including a rotor that rotates in response to a rotating magnetic field generated by a stator. In this rotating electrical machine, a stator and a circuit unit that controls energization of the stator are fixed to a center piece.

JP2015-122844A

  By the way, from the viewpoint of electromagnetic compatibility, it is desired to reduce electrical noise when the motor is operating.

  An object of the present invention is to obtain a rotating electrical machine capable of reducing electrical noise in consideration of the above facts.

  The rotating electrical machine according to claim 1, wherein a stator has a winding wound around a stator core, a circuit board that forms part of a control unit that controls energization of the winding, and the stator generates a magnetic field. And a rotor that is rotated by a resin material, a holder to which the stator and the circuit board are fixed, and a conductive material, and at least one of the stator and the circuit board And a fixing member that is fixed to the holder and electrically connects the stator core and the circuit board.

  According to the rotating electrical machine of the first aspect, the stator generates a magnetic field by controlling the energization to the winding by the control unit. As a result, the rotor rotates. Here, in the rotary electric machine according to claim 1, the stator and the circuit board are fixed to a holder formed using a resin material. Further, at least one of the stator and the circuit board is fixed to the holder by a fixing member formed using a conductive material. The stator core of the stator and the circuit board of the control unit are electrically connected via a fixing member. Thereby, the electric noise generated in the control unit can be looped between the circuit board and the stator core. As a result, the electrical noise is suppressed from being released to the outside of the rotating electrical machine, and the electrical noise can be reduced.

  The rotating electrical machine according to claim 2 is the rotating electrical machine according to claim 1, wherein the circuit board is fixed to a side of the holder opposite to a side where the stator is fixed, and a part of the fixing member is It is exposed on the circuit board side.

  According to the rotating electric machine of the second aspect, the stator core of the stator and the circuit board of the control unit are electrically connected via the fixing member by electrically connecting the portion exposed to the circuit board side of the fixing member to the circuit board. Can be connected to.

  The rotating electrical machine according to claim 3 is the rotating electrical machine according to claim 2, wherein the fixing member is a nut fixed to the holder and a bolt inserted into the stator core and screwed to the nut, and the nut Is exposed to the circuit board side.

  According to the rotating electrical machine of the third aspect, the stator is fixed to the holder by the bolt inserted through the stator core being screwed into the nut embedded in the holder. And the part exposed to the circuit board side in the nut is electrically connected to the circuit board, so that the stator core of the stator and the circuit board of the control unit can be electrically connected via the nut and the bolt.

  The rotating electrical machine according to claim 4 is the rotating electrical machine according to claim 3, wherein an elastic member formed of a conductive material is joined to the circuit board, and the circuit board is fixed to the holder. In this state, the elastic member is in contact with the nut in a bent state.

  According to the rotating electric machine according to claim 4, the portion of the nut embedded in the holder is electrically connected to the circuit board via the elastic member, so that the stator core of the stator and the circuit of the control unit are electrically connected. A board | substrate can be electrically connected through a fixing member. In addition, in the state where the circuit board is fixed to the holder, the elastic member is configured to be in contact with the nut while being bent, so that the variation in the clearance between the circuit board and the holder is caused by the bending of the elastic member. Can be absorbed.

  The rotating electrical machine according to claim 5 is the rotating electrical machine according to claim 3 or claim 4, wherein the nut is a cap nut with the circuit board side closed.

  According to the rotating electrical machine of the fifth aspect, the nut into which the bolt is screwed is a cap nut with the circuit board side closed. Therefore, even if conductive foreign matter (such as sliding powder between the bolt and nut) is generated when the bolt is screwed into the nut, the conductive foreign matter is prevented from entering the circuit board side. Or it can be prevented.

  The rotating electrical machine according to claim 6 is the rotating electrical machine according to any one of claims 1 to 5, wherein the fixing member is provided at a plurality of locations, and the winding is provided on the circuit board. And the fixing member farthest from the terminal portion of the winding electrically connects the stator core and the circuit board.

  According to the rotating electric machine of the sixth aspect, the fixing member farthest from the terminal portion of the winding among the plurality of fixing members electrically connects the stator core and the circuit board. Thereby, the electrical noise generated in the control unit can be looped between the circuit board and the stator core via the one fixing member. As a result, the electrical noise is suppressed from being released to the outside of the rotating electrical machine, and the electrical noise can be reduced.

  The rotating electrical machine according to claim 7 is the rotating electrical machine according to any one of claims 1 to 6, wherein the rotor is rotatably supported by a shaft portion formed using a conductive member. The shaft portion is electrically connected to the circuit board.

  According to the rotating electric machine of the seventh aspect, since the shaft portion that supports the rotor is electrically connected to the circuit board, the electric noise radiated from the rotor can be reduced.

It is sectional drawing which shows a blower motor. It is a top view which shows a blower motor, and has shown the state which removed the rotor. It is a rear view which shows a blower motor, and has shown the state which removed the cover. It is sectional drawing which shows the blower motor of another form.

  A rotating electrical machine according to an embodiment of the present invention will be described with reference to FIGS. In addition, the arrow Z direction, the arrow R direction, and the arrow C direction that are appropriately shown in the drawings indicate one side of the rotating electrical machine (rotor) in the rotational axis direction, one side in the rotational radial direction, and one side in the rotational circumferential direction. In the following description, when only the axial direction, radial direction, and circumferential direction are indicated, the rotational axis direction, rotational radial direction, and rotational circumferential direction of the rotating electrical machine (rotor) are indicated unless otherwise specified.

  As shown in FIG. 1, a blower motor 10 as a rotating electrical machine of the present embodiment is an outer rotor type brushless motor that constitutes a part of an air conditioner for a vehicle. The blower motor 10 includes a stator 12 that generates a rotating magnetic field, a rotor 14 that rotates in response to the rotating magnetic field generated by the stator 12, and a control unit 16 that controls energization of the stator 12. The blower motor 10 also includes a holder 18 on which the stator 12 and the control unit 16 are fixed and the rotor 14 is rotatably supported.

  As shown in FIG. 2, the stator 12 is formed by winding a conductive winding 22 around a stator core 20 formed using a magnetic material such as iron or steel. The stator core 20 has an annular portion 24 formed in an annular shape when viewed from the axial direction, and a plurality of (this embodiment) that extends radially outward from the annular portion 24 and is arranged at equal intervals in the circumferential direction. And 12 teeth portions 26 in the form. The annular portion 24 is formed with three bolt insertion holes 30 through which bolts 28 (see FIG. 1) as fixing members formed using a conductive member such as a steel material are inserted. The holes 30 are arranged at equal intervals along the circumferential direction. A coil 32 is formed around the tooth portion 26 by winding a conductive winding 22. In this embodiment, twelve coils 32 are formed by winding the windings 22 around each tooth portion 26.

  As shown in FIG. 1, the rotor 14 is configured by joining a rotor magnet 36 to an inner peripheral portion of a rotor housing 34. The rotor housing 34 is formed in a bottomed cylindrical shape in which the holder 18 side (the other side in the axial direction (the side opposite to the arrow Z direction)) is opened. The rotor housing 34 has a bottom wall portion 42 having a bearing receiving recess 40 in which two bearings 38 are fixed to the shaft center portion by press-fitting or the like, and is bent from the outer peripheral end of the bottom wall portion 42 toward the holder 18 side. And a peripheral wall portion 44 that extends. A rotor magnet 36 that is a ring magnet or a segment magnet is joined to the inner peripheral surface of the peripheral wall portion 44 via an adhesive or the like. Then, the shaft 14 fixed to the holder 18 described later is inserted into the two bearings 38 fixed to the rotor housing 34, so that the rotor 14 is rotatably supported by the shaft 46.

  The control unit 16 includes a circuit board 48 formed in a plate shape extending in the radial direction with the axial direction as the thickness direction, and circuit elements (not shown) attached to the circuit board 48. By supplying power to the control unit 16 via an external connector connected to the connector unit 50 of the holder 18 to be described later, energization to the winding 22 (coil 32) of the stator 12 is switched. The circuit board 48 is formed using a copper plate or the like, and a spring 52 as an elastic member that can be bent and deformed in the thickness direction is joined to the circuit board 48. The spring 52 is joined to a portion corresponding to the ground in a conductive pattern portion (not shown) formed on the circuit board 48 by soldering. Further, the terminal portion 22A of the winding 22 is connected to the circuit board 48.

  The holder 18 is formed using a resin material that is a highly insulating material. The holder 18 is a cross-sectional view cut along the axial direction (in the cross-sectional view shown in FIG. 1), and a base 54 that separates the side on which the stator 12 and the rotor 14 are disposed from the side on which the control unit 16 is disposed. It is equipped with. A cylindrical boss 56 is erected on one axial side of the base 54. The shaft portion 46 is fixed to the shaft center portion of the boss portion 56 by insert molding or the like. Further, a bolt insertion hole 58 into which a bolt 28 for fixing the stator 12 to the holder 18 is inserted is formed in the outer peripheral portion of the boss portion 56. Furthermore, a fixing member to which the tip end of the bolt 28 inserted into the bolt insertion hole 58 is screwed and a cap nut 60 as a nut are inserted into the base 54 on the other axial side of the bolt insertion hole 58 by insert molding. It is fixed. The cap nut 60 may be fixed to the holder 18 by a method other than insert molding. The cap nut 60 is open on one axial side (arrow Z direction side) and closed on the other axial side. As shown in FIGS. 1 and 3, the end surface (closed end surface 60 </ b> A) on the other side in the axial direction of the cap nut 60 is exposed to the circuit board 48 side. In the present embodiment, three bolt insertion holes 58 corresponding to the three bolts 28 are formed, and three cap nuts 60 are embedded in the holder 18.

  In addition, on the other side in the axial direction of the holder 18, a control unit accommodating recess 62 in which the control unit 16 is disposed is formed. The base 54 that forms the bottom of the control unit accommodating recess 62 is provided with four tapping screw screwing portions 64 into which tapping screws (not shown) for fixing the circuit board 48 to the holder 18 are screwed. Then, the tapping screw inserted through the circuit board 48 is screwed into the tapping screw screwing portion 64 so that the circuit board 48 is fixed to the holder 18. In the state where the circuit board 48 is fixed to the holder 18, the spring 52 fixed to the circuit board 48 is in contact with the closed end surface 60 </ b> A of one cap nut 60 while being bent. The single cap nut 60 is a cap nut 60 disposed at a position farthest from the portion of the circuit board 48 to which the end portion of the winding 22 is connected. In addition, six winding insertion holes 66 through which the terminal portions of the windings 22 forming the coils 32 of the stator 12 are inserted are formed in the base 54 that forms the bottom of the control unit accommodating recess 62. The end portion 22A of the winding 22 inserted through the winding insertion hole 66 is joined to the circuit board 48 by soldering or the like. The open end of the control unit receiving recess 62 is closed by a cover member 68 attached to the holder 18. Further, the base 54 of the holder 18 is formed with three fixing bolt insertion holes 70 for fixing bolts for fixing the blower motor 10 to other members constituting the vehicle air conditioner.

(Operation and effect of this embodiment)
Next, the operation and effect of this embodiment will be described.

  As shown in FIG. 1, in the blower motor 10 according to the present embodiment, power is supplied to the control unit 16 via an external connector connected to the connector unit 50 of the holder 18, so that the winding 22 (coil) of the stator 12 is provided. The energization to 32) is switched. As a result, a rotating magnetic field is generated around the stator 12, and the rotor 14 rotates around the shaft portion 46.

  Here, in the present embodiment, the stator core 20 of the stator 12 and the circuit board 48 of the control unit 16 include one bolt 28 for fixing the stator 12 to the holder 18, a cap nut 60 to which the bolt 28 is screwed, and It is electrically connected via a spring 52 that contacts the cap nut 60. Thereby, as indicated by an arrow Y in FIG. 1, the electric noise generated by the control unit 16 can be looped between the circuit board 48 and the stator core 20. As a result, the electrical noise is suppressed from being released to the outside of the blower motor 10, and the electrical noise generated from the blower motor 10 can be reduced. The electrical noise generated in the control unit 16 is generated from a MOSFET or the like that is a switching element for switching energization to each winding 22 forming the coil 32.

  In the present embodiment, when the circuit board 48 is fixed to the holder 18, the spring 52 fixed to the circuit board 48 is in contact with the closed end surface 60 </ b> A of one cap nut 60 while being bent. Thereby, even if the clearance between the circuit board 48 and the closed end surface 60 </ b> A of the cap nut 60 embedded in the holder 18 varies, the variation can be absorbed by the bending of the spring 52.

  Furthermore, in this embodiment, the nut for fixing the stator 12 is the cap nut 60 with the circuit board 48 side closed. Thus, even if conductive foreign matter (such as sliding powder between the bolt and the nut) is generated by screwing the bolt 28 to the cap nut 60, the conductive foreign matter is a holder in which the circuit board 48 is accommodated. It is possible to suppress or prevent intrusion into the 18 control unit housing recess 62 side.

  In the present embodiment, the example in which the nut for fixing the stator 12 is the cap nut 60 has been described, but the present invention is not limited to this. For example, when the conductive foreign matter does not occur or is at a negligible level, a through nut may be used instead of the cap nut 60.

  Further, in this embodiment, the example in which the stator core 20 of the stator 12 and the circuit board 48 of the control unit 16 are electrically connected via the bolts 28, the cap nuts 60, and the springs 52 has been described. It is not limited. For example, the circuit board 48 and the closed end surface 60 </ b> A of the cap nut 60 may be brought into direct contact without providing the spring 52.

  Further, in the present embodiment, the stator core 20 of the stator 12 and the circuit board 48 of the control unit 16 are electrically connected via the bolts 28 for fixing the stator 12 to the holder 18 and the cap nuts 60 to which the bolts 28 are screwed. Although an example of connecting to is described, the present invention is not limited to this. For example, the stator core 20 of the stator 12 and the circuit board 48 of the control unit 16 may be electrically connected via fixing members such as bolts and nuts for fixing the circuit board 48 to the holder 18. Further, the stator core 20 of the stator 12 and the circuit board 48 of the control unit 16 may be electrically connected via a fixing member other than bolts and nuts.

(Other types of blower motor 72)
Next, a blower motor 72 as a rotating electrical machine according to another embodiment of the above embodiment will be described. In addition, in the blower motor 72 of another form, the member and part corresponding to the blower motor 10 of the said embodiment are attached | subjected with the same code | symbol as each member and part of the blower motor 10, and the description is abbreviate | omitted.

  As shown in FIG. 4, in the blower motor 72 of another form, the end surface 46A on the other side in the axial direction of the shaft portion 46 formed using a metal material that is a conductive member is exposed to the circuit board 48 side. Yes. A spring 52 joined to the circuit board 48 is in contact with the end face 46A on the other axial side of the shaft portion 46 in a bent state. Thereby, the rotor 14 is grounded to the circuit board 48 via the bearing 38 and the shaft portion 46.

  According to the blower motor 72 of the other form described above, the rotor 14 is grounded to the circuit board 48 via the bearing 38 and the shaft portion 46, thereby reducing electrical noise radiated from the rotor 14. it can.

  Although one embodiment of the present invention has been described above, the present invention is not limited to the above, and various modifications other than the above can be implemented without departing from the spirit of the present invention. Of course.

10 Blower motor (rotary electric machine)
12 Stator 14 Rotor 16 Control unit 18 Holder 20 Stator core 22 Winding 28 Bolt (fixing member)
46 Shaft part 48 Circuit board 52 Spring (elastic member)
60 Cap nut (fixing member, nut)
72 Blower motor (rotary electric machine)

Claims (7)

A stator having a winding wound around a stator core;
A circuit board constituting a part of a control unit for controlling energization to the winding;
A rotor that rotates when the stator generates a magnetic field;
A holder formed with a resin material, and the stator and the circuit board are fixed;
A fixing member formed using a conductive material, fixing at least one of the stator and the circuit board to the holder, and electrically connecting the stator core and the circuit board;
Rotating electric machine with The circuit board is fixed on the opposite side of the holder from the side on which the stator is fixed,
The rotating electrical machine according to claim 1, wherein a part of the fixing member is exposed to the circuit board side. The fixing member is a nut fixed to the holder and a bolt inserted through the stator core and screwed into the nut,
The rotating electrical machine according to claim 2, wherein a part of the nut is exposed to the circuit board side. An elastic member formed using a conductive material is bonded to the circuit board,
The rotating electrical machine according to claim 3, wherein in a state where the circuit board is fixed to the holder, the elastic member is in contact with the nut while being bent.   The rotating electrical machine according to claim 3 or 4, wherein the nut is a cap nut with the circuit board side closed. The fixing member is provided at a plurality of locations,
A terminal portion of the winding is connected to the circuit board,
The rotating electrical machine according to any one of claims 1 to 5, wherein the fixing member farthest from a terminal portion of the winding electrically connects the stator core and the circuit board. The rotor is rotatably supported by a shaft portion formed using a conductive member,
The rotating electrical machine according to claim 1, wherein the shaft portion is electrically connected to the circuit board.