JP6946859B2 - Rotating machine - Google Patents

Description

The present invention relates to a rotary electric machine.

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

Japanese Unexamined Patent Publication No. 2015-122844

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 rotary electric machine capable of reducing electrical noise in consideration of the above facts.

The rotary electric machine according to claim 1 has a stator in which a winding is wound around a stator core, a circuit board that forms a part of a control unit that controls energization of the winding, and the stator generating a magnetic field. It is formed by using a rotor that rotates with a resin material, a holder to which the stator and the circuit board are fixed, and at least one of the stator and the circuit board, which is formed by using a conductive material. A fixing member which is fixed to the holder and electrically connects the stator core and the circuit board is provided . The fixing members are provided at a plurality of places, and the circuit board is provided with a winding of the winding. The terminal portion is connected, and the fixing member farthest from the terminal portion of the winding electrically connects the stator core and the circuit board .

According to the rotary electric machine according to claim 1, the stator generates a magnetic field by controlling the energization of the winding by the control unit. This causes the rotor to rotate. Here, in the rotary electric machine according to claim 1, the stator and the circuit board are fixed to a holder formed of a resin material. Further, at least one of the stator and the circuit board is fixed to the holder by a fixing member formed of a conductive material. The stator core of the stator and the circuit board of the control unit are electrically connected via a fixing member. As a result, the electrical noise generated in the control unit can be looped between the circuit board and the stator core. As a result, the electric noise is suppressed from being emitted to the outside of the rotating electric machine, and the electric noise can be reduced.
Further, according to the rotary electric machine according to claim 1, the fixing member farthest from the terminal portion of the winding in the plurality of fixing members electrically connects the stator core and the circuit board. As a result, 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 electric noise is suppressed from being emitted to the outside of the rotating electric machine, and the electric noise can be reduced.

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

According to the rotary electric machine according to claim 2, by electrically connecting the portion of the fixing member exposed on the circuit board side to the circuit board, the stator core of the stator and the circuit board of the control unit are electrically connected via the fixing member. Can be connected to.

The rotary electric machine according to claim 3 is the rotary electric 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 into the nut. Is partially exposed on the circuit board side.

According to the rotary electric machine according to claim 3, the stator is fixed to the holder by screwing the bolt inserted into the stator core into the nut embedded in the holder. Then, by electrically connecting the portion of the nut exposed to the circuit board side to the circuit board, 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 rotary electric machine according to claim 4 is the rotary electric machine according to claim 3, wherein an elastic member formed by using 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 rotary electric machine according to claim 4, the portion of the nut embedded in the holder exposed on the circuit board side is electrically connected to the circuit board via an elastic member to electrically connect the stator core of the stator and the circuit of the control unit. The substrate can be electrically connected via the fixing member. Further, when the circuit board is fixed to the holder, the elastic member is in contact with the nut in a bent state, so that the clearance between the circuit board and the holder varies due to the bending of the elastic member. Can be absorbed.

The rotary electric machine according to claim 5 is the rotary electric machine according to claim 3 or 4, wherein the nut is a cap nut whose circuit board side is closed.

According to the rotary electric machine according to claim 5, the nut into which the bolt is screwed is a cap nut whose circuit board side is closed. From this, even if conductive foreign matter (sliding powder between the bolt and nut, etc.) is generated by screwing the bolt into the nut, it is possible to prevent the conductive foreign matter from entering the circuit board side. Or it can be prevented.

The rotary electric machine according to claim 6 is the rotary electric machine according to any one of claims 1 to 5 , wherein the rotor is rotatably supported by a shaft portion formed by using a conductive member. The shaft portion is electrically connected to the circuit board.

According to the rotary electric machine according to claim 6, the electric noise radiated from the rotor can be reduced by electrically connecting the shaft portion supporting the rotor to the circuit board.

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

The rotary electric machine according to the embodiment of the present invention will be described with reference to FIGS. 1 to 3. The arrow Z direction, arrow R direction, and arrow C direction, which are appropriately shown in the drawing, indicate one side in the rotation axis direction, one side in the rotation radial direction, and one side in the rotation circumferential direction of the rotary electric machine (rotor), respectively. In the following, when simply indicating the axial direction, the radial direction, and the circumferential direction, the rotational axis direction, the rotational radial direction, and the circumferential direction of the rotary electric machine (rotor) shall be indicated unless otherwise specified.

As shown in FIG. 1, the blower motor 10 as a rotary electric machine of the present embodiment is an outer rotor type brushless motor that constitutes a part of an air conditioner of 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. Further, the blower motor 10 includes a holder 18 to 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 of a magnetic material such as iron or steel. The stator core 20 includes an annular portion 24 formed in an annular shape when viewed from the axial direction, and a plurality of stator cores 20 extending outward in the radial direction from the annular portion 24 and arranged at equal intervals along the circumferential direction (this embodiment). In the form, it is provided with (12) teeth portions 26. The annular portion 24 is formed with three bolt insertion holes 30 through which bolts 28 (see FIG. 1) as fixing members formed by using a conductive member such as a steel material are inserted, and three bolt insertion holes 30 are formed. The holes 30 are arranged at equal intervals along the circumferential direction. Further, a coil 32 is formed by winding a conductive winding 22 around the teeth portion 26. In the present embodiment, 12 coils 32 are formed by winding the winding 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 open. The rotor housing 34 is bent toward the holder 18 side from the bottom wall portion 42 having a bearing accommodating recess 40 in which two bearings 38 are fixed to the axial center portion by press fitting or the like, and the outer peripheral end of the bottom wall portion 42. It is provided with an extending peripheral wall portion 44. A ring magnet or a rotor magnet 36, which is a segment magnet, is joined to the inner peripheral surface of the peripheral wall portion 44 via an adhesive or the like. Then, the rotor 14 is rotatably supported by the shaft portion 46 by inserting the shaft portion 46 fixed to the holder 18, which will be described later, into the two bearings 38 fixed to the rotor housing 34.

The control unit 16 includes a plate-shaped circuit board 48 extending in the radial direction with the axial direction as the thickness direction, and a circuit element (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, which will be described later, the energization of the winding 22 (coil 32) of the stator 12 can be switched. Further, the circuit board 48 is formed by using a copper plate or the like, and a spring 52 as an elastic member that can bend and deform in the thickness direction is joined to the circuit board 48. The spring 52 is soldered to a portion corresponding to the ground in a conductive pattern portion (not shown) formed on the circuit board 48. Further, the terminal portion 22A of the winding 22 is connected to the circuit board 48.

The holder 18 is formed by using a resin material which 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 the base portion 54 that separates the side on which the stator 12 and the rotor 14 are arranged from the side on which the control unit 16 is arranged. I have. A cylindrical boss portion 56 is erected on one side of the base portion 54 in the axial direction. The shaft portion 46 described above 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. Further, at the base 54 on the other side of the bolt insertion hole 58 in the axial direction, a fixing member into which the tip of the bolt 28 inserted into the bolt insertion hole 58 is screwed and a cap nut 60 as a nut are inserted. 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 side in the axial direction (side in the direction of arrow Z) and closed on the other side in the axial direction. Then, as shown in FIGS. 1 and 3, the end surface (closed end surface 60A) on the other side in the axial direction of the cap nut 60 is exposed to the circuit board 48 side. In this 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.

Further, on the other side of the holder 18 in the axial direction, a control unit accommodating recess 62 in which the control unit 16 is arranged is formed. The base 54 forming 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. Further, 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 60A of one cap nut 60 in a bent state. This one cap nut 60 is a cap nut 60 arranged at the position farthest from the portion of the circuit board 48 to which the terminal portion of the winding 22 is connected. Further, the base 54 forming the bottom of the control unit accommodating recess 62 is formed with six winding insertion holes 66 into which the terminal portion of the winding 22 forming each coil 32 of the stator 12 is inserted. The terminal 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 accommodating recess 62 is closed by the 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 the blower motor 10 to other members constituting the air conditioner of the vehicle.

(Action 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 of 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 supplied. 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 have one bolt 28 for fixing the stator 12 to the holder 18, a cap nut 60 to which the bolt 28 is screwed, and a cap nut 60. It is electrically connected via a spring 52 that comes into contact with the cap nut 60. As a result, as shown by the arrow Y in FIG. 1, the electrical noise generated by the control unit 16 can be looped between the circuit board 48 and the stator core 20. As a result, the electric noise is suppressed from being emitted to the outside of the blower motor 10, and the electric noise generated from the blower motor 10 can be reduced. The electrical noise generated by the control unit 16 is generated from a MOSFET or the like which is a switching element for switching the energization of each winding 22 forming the coil 32.

Further, 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 60A of one cap nut 60 in a bent state. As a result, even if the clearance between the circuit board 48 and the closed end surface 60A of the cap nut 60 embedded in the holder 18 varies, the variation can be absorbed by the bending of the spring 52.

Further, in the present embodiment, the nut for fixing the stator 12 is a cap nut 60 whose circuit board 48 side is closed. From this, even if conductive foreign matter (sliding powder between the bolt and nut, etc.) is generated by screwing the bolt 28 into the cap nut 60, the holder in which the conductive foreign matter is housed in the circuit board 48. It is possible to suppress or prevent invasion of the control unit accommodating recess 62 side of 18.

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

Further, in the present embodiment, an 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 bolts 28, cap nuts 60, and springs 52 has been described. Not limited. For example, the circuit board 48 and the closed end surface 60A of the cap nut 60 may be brought into direct contact with each other 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 a bolt 28 for fixing the stator 12 to the holder 18 and a cap nut 60 to which the bolt 28 is screwed. Although the example connected to the above has been 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 fixing members other than bolts and nuts.

(Other forms of blower motor 72)
Next, the blower motor 72 as a rotary electric machine of another embodiment of the above embodiment will be described. In the blower motor 72 of another form, the members and parts corresponding to the blower motor 10 of the above embodiment are designated by the same reference numerals as the members and parts of the blower motor 10, and the description thereof will be 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 by using a metal material which is a conductive member is exposed to the circuit board 48 side. There is. The spring 52 joined to the circuit board 48 is in contact with the end surface 46A on the other side in the axial direction of the shaft portion 46 in a bent state. As a result, 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 another form described above, the rotor 14 is grounded to the circuit board 48 via the bearing 38 and the shaft portion 46, so that the electrical noise radiated from the rotor 14 can be reduced. can.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above, and can be modified in various ways other than the above within a range not deviating from the gist thereof. Of course.

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

Claims (6)

A stator with windings wound around the stator core,
A circuit board that constitutes a part of the control unit that controls the energization of the winding
A rotor that rotates when the stator generates a magnetic field,
A holder formed of a resin material and to which the stator and the circuit board are fixed,
A fixing member formed of a conductive material, which fixes at least one of the stator and the circuit board to the holder and electrically connects the stator core and the circuit board.
Equipped with a,
The fixing members are provided at a plurality of places, and the fixing members are provided at a plurality of places.
The terminal portion of the winding is connected to the circuit board.
A rotary electric machine in which the fixing member farthest from the terminal portion of the winding electrically connects the stator core and the circuit board. The circuit board is fixed in the holder on the side opposite to the side on which the stator is fixed.
The rotary electric machine according to claim 1, wherein a part of the fixing member is exposed on the circuit board side. The fixing member is a nut fixed to the holder and a bolt inserted into the stator core and screwed into the nut.
The rotary electric machine according to claim 2, wherein a part of the nut is exposed on the circuit board side. An elastic member formed of a conductive material is bonded to the circuit board.
The rotary electric machine according to claim 3, wherein when the circuit board is fixed to the holder, the elastic member is in contact with the nut in a bent state. The rotary electric machine according to claim 3 or 4, wherein the nut is a cap nut whose circuit board side is closed. The rotor is rotatably supported by a shaft portion formed by using a conductive member.
The rotary electric machine according to any one of claims 1 to 5 , wherein the shaft portion is electrically connected to the circuit board.

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