JP7051621B2 - Brushless motor - Google Patents

Description

The present invention relates to a brushless motor in which a bearing holder for supporting a shaft and a detection element for detecting a rotational position are arranged at an open end of a motor case.

The brushless motor has a shaft having a rotor provided with a magnetic field magnet and a stator provided with an armature winding. The position of the rotor is detected by the Hall element, which is a magnetically sensitive element, and the energization timing for each stator coil is controlled by the inverter based on the detection signal of the Hall element. The shaft projects from the open end of the motor case that houses the stator and rotor, and the rotational movement of the shaft is transmitted from the protruding end of the shaft to an external driven component.

The shaft is rotatably supported by bearings, which are incorporated into metal bearing holders. In the electric blower described in Patent Document 1, when the resin parts such as the fan case and the motor case are injection-molded, the bearing holder is integrally insert-molded into the resin parts.

In a brushless motor in which the shaft is discharged from the open end of the motor case and the rotational movement of the shaft is transmitted to an external component, bearings are arranged on the closed end side and the open end side of the motor case. .. The bearing holder for supporting the bearing arranged on the open end side can be integrally molded with the bracket, which is a resin part mounted on the open end of the motor case.

Japanese Unexamined Patent Publication No. 2010-209984

When a cylindrical metal part such as a bearing holder of a motor is insert-molded into a resin part, a flange portion is provided in the cylindrical metal part and the flange portion is insert-molded into the resin part. In this way, when the flange part is insert-molded into a resin part, when the flange part is circular, the flange part shifts in the direction of rotation with respect to the resin part due to the vibration applied to the motor, and the durability of the motor It is possible to reduce the sex. Therefore, in order to increase the adhesion strength between the flange portion and the resin component, measures such as enlarging the flange portion and pressing the flange portion with a pin are taken.

However, increasing the diameter of the flange portion leads to an increase in the size of the motor itself and an increase in the number of parts. In particular, in a motor arranged in a limited space such as a motor for a vehicle brake, it is a big problem to reduce the size while maintaining durability.

An object of the present invention is to achieve miniaturization of a brushless motor while maintaining durability.

The brushless motor of the present invention includes a stator fixed inside a motor case having a bottomed cylindrical portion, a rotor provided with a shaft supported by bearings and rotatably supported inside the stator, and the motor case. A brushless motor comprising a resin bracket attached to the axial end of the bearing holder and a bearing holder having a cylindrical portion holding the bearing and being insert-formed into the bracket, wherein the bearing holder has the cylindrical portion. A flange portion extending outward in the radial direction, a sensor board on which a plurality of detection sensors for detecting the rotational position of the rotor are mounted, and a sensor wiring for sending an output signal from the detection sensor. A terminal arrangement portion for a sensor whose distance from the center point changes from one end to the other end is provided on the outer peripheral surface of the flange portion, and an internal terminal of the sensor wiring is provided along the terminal arrangement portion. Placed.

A bearing holder is fixed to the resin bracket attached to the motor case, and the bearing holder has a cylindrical portion that holds the bearing that rotatably supports the shaft, and a flange portion that is insert-molded into the bracket. .. The bracket is provided with the sensor wiring of the detection sensor for detecting the position in the rotation direction of the rotor, and the internal terminal of the sensor wiring is arranged in the terminal arrangement portion for the sensor provided on the outer peripheral surface of the flange portion. Will be done. The distance from the center point of the flange portion of the terminal arrangement portion changes from one end to the other end, and when the flange portion is insert-molded in the bracket, the terminal arrangement portion adheres to the resin material of the bracket. , Prevents the flange from shifting and rotating with respect to the bracket. As a result, the adhesion strength between the flange portion and the bracket can be increased without increasing the outer diameter of the flange portion, and the durability can be improved while achieving miniaturization of the motor.

It is a perspective view which shows the appearance of the brushless motor which is one Embodiment. It is a vertical sectional view of FIG. It is an enlarged cross-sectional view of FIG. It is a block diagram which shows the rotation control circuit of a motor. FIG. 2 is an enlarged side view showing a connector portion provided on the left side in FIG. 2. It is a top view which shows the inner surface of the bracket shown in FIG. It is a top view which shows the wiring incorporated in a bracket. It is a perspective view of FIG. It is a top view which shows the arrangement relationship between the flange part of a bearing holder, and the inner terminal.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. As shown in FIGS. 1 and 2, the brushless motor 10 includes a motor case 11. The motor case 11 is formed by pressing a metal plate by deep drawing or the like, and as shown in FIG. 2, has a bottomed cylindrical portion 11b provided with a bottom wall portion 11a, and the cylindrical portion 11b. A flange portion 11c is provided at the open end portion 12 of the above. A resin bracket 13 is attached to the flange portion 11c, and the bracket 13 is attached to the axial end portion of the motor case 11.

A plurality of collars 14a to 14c are attached to the bracket 13, and the brushless motor 10 is attached to a member (not shown) by a screw member penetrating each of the collars 14a to 14c. The brushless motor 10 can be applied to drive a brake device of an automobile, in which case the motor case 11 is attached to the speed reducer by a screw member penetrating the collars 14a to 14c.

As shown in FIGS. 2 and 3, a stator 15 is fixed to the cylindrical portion 11b of the motor case 11, and a rotor 16 is rotatably supported inside the stator 15 through an air gap, that is, a gap 17. To. The rotor 16 has a shaft 18 of a motor, the base end portion of the shaft 18 is rotatably supported by a bearing 21 on a motor case 11, and the tip end portion is rotatably supported by a bracket 13 by a bearing 22. The bearing 21 is held by a tubular portion 23 provided on the bottom wall portion 11a of the motor case 11. On the other hand, the bearing 22 is held by the metal bearing holder 24 fixed to the bracket 13. The bearing holder 24 has a cylindrical portion 25 that holds the bearing 22, and a flange portion 26 that is connected to the cylindrical portion 25 and extends radially outward and is fixed to the bracket 13.

When the lower end of the shaft 18 in FIG. 2 is the base end of the shaft 18 and the upper end is the tip, the pinion gear 27 is attached to the tip. When the brushless motor 10 is applied to drive a brake device, the rotation of the pinion gear 27 is transmitted to the feed screw shaft via a reduction gear mechanism (not shown). The lead screw shaft is screw-coupled to a reciprocating member mounted axially reciprocatingly on the caliper of the brake device. A pad pressed against the brake disc of the electric brake device of the automobile is provided on the reciprocating member and the claw portion of the caliper facing the reciprocating member, and a braking force is applied to the automobile by the brushless motor 10.

As shown in FIG. 2, the shaft 18 is provided with a magnet mounting portion 28 having an outer peripheral surface portion having a diameter larger than that of both ends, and a ring magnet is provided on the outer periphery of the magnet mounting portion 28 by an adhesive 29. 31 is fixed. The ring magnet 31 is formed by alternately magnetizing a cylindrical member made of a magnetic material with N poles and S poles as magnetic poles shifted in the circumferential direction. Therefore, the magnetic poles are magnetized on the ring magnet 31 in a state where the different polarities are adjacent to each other in the circumferential direction. As shown in FIG. 3, the ring magnet 31 is magnetized with 10 magnetic poles in the circumferential direction, and the rotor 16 has 10 poles. In FIG. 3, the boundary portion of the magnetic pole of the ring magnet 31 is shown by a broken line. As described above, the brushless motor 10 is a ring magnet type, and unlike a surface magnet type or an embedded magnet type rotor, magnetic poles can be evenly allocated in the circumferential direction, and the rotor 16 requires a small number of assembly steps. Can be manufactured. In the surface magnet type rotor, it is conceivable that the arc-shaped magnet attached to the outer peripheral surface of the cylindrical member will come off, but the ring magnet 31 can improve the durability of the motor.

The stator 15 has a substantially cylindrical stator core 32. As shown in FIG. 3, the stator core 32 is formed by combining nine tooth portions 33 in the circumferential direction. Each tooth portion 33 is formed by laminating a plurality of metal plates (electromagnetic steel sheets) punched by press working. Each metal plate is provided with a through hole (not shown) for positioning during stacking. An insulator 34 made of an insulating resin material is attached to each tooth portion 33, and a coil 35 is wound around the outside of the insulator 34. A coil 35 is wound around the nine teeth portions 33, and the stator 15 shown in FIGS. 1 to 3 has nine coils 35.

Each coil 35 constitutes three phases of U phase, V phase, and W phase in order in the circumferential direction, and each phase is formed by the three coils 35. As shown in FIG. 2, the bus bar unit 36 is arranged on the end surface of the stator 15 on the distal end side. The bus bar unit 36 is provided with coil terminals 37 for each phase, and the coil terminals 37 are connected to an external power supply source. In FIG. 2, one of the three coil terminals 37 for three phases is shown.

A sensor disk 38 is attached to the shaft 18 in order to detect the position of the rotor 16 in the rotational direction. The sensor disk 38 is provided with a magnet. A sensor board 39 is attached to the bracket 13 so as to face the sensor disk 38, and a Hall element that responds to the magnetic force of a magnet provided on the sensor disk 38 is provided on the sensor board 39.

FIG. 4 is a block diagram showing a rotation control circuit of the motor. The rotation control circuit has three Hall elements 41a to 41c corresponding to the three-phase coil, and each Hall element is attached to the sensor substrate 39 shown in FIG. 2 as described above. Each of the Hall elements 41a to 41c detects the magnetic flux of the magnet provided on the sensor disk 38, and outputs a detection signal when the polarity of the magnetic pole portion of the rotor 16 changes from the N pole to the neutral point of the S pole. It is a magnetic field detection element as a detection sensor that outputs. The position of the rotor 16 is detected based on the detection signal from the Hall element, and the energization switching operation for each coil 35 is performed. The sensor for detecting the rotation position is not limited to the Hall element, and a Hall IC in which an electronic element having a comparator function and a Hall element are integrated into one chip may be used.

The rotation control circuit of the motor includes an inverter circuit 42 for controlling the drive current for each of the U-phase, V-phase, and W-phase coils 35. The inverter circuit 42 is a three-phase full-bridge inverter circuit, and has two switching elements T1 and T2 connected in series, two switching elements T3 and T4, and two switching elements T5 and T6, respectively. Each is connected to the output terminals of the positive electrode and the negative electrode of the DC power supply 43. One coil terminal of the U-phase coil 35 is connected between the two switching elements T1 and T2. One coil terminal of the V-phase coil 35 is connected between the two switching elements T3 and T4. One coil terminal of the W phase coil 35 is connected between the two switching elements T5 and T6. The other coil terminals of the U-phase, V-phase, and W-phase coils 35 are connected to each other, and each coil 35 has a star connection. The connection method may be a delta connection. By adjusting the timing of the control signal supplied to each switching element, electric power is applied to the coil 35 to control the commutation operation for each coil 35.

The rotation control circuit of the motor has a controller 44, and a control signal is sent from the controller 44 to the inverter circuit 42 via the control signal output circuit 45. The detection signals of the Hall elements 41a to 41c as the rotation position detection sensor are sent to the rotor position detection circuit 46. A signal is sent from the rotor position detection circuit 46 to the controller 44. The controller 44 has a microprocessor that calculates a control signal and a memory that stores a control program, data, and the like.

The inverter circuit 42, the controller 44, the rotor position detection circuit 46, and the like are provided outside the motor, and power is supplied to the coils of each phase from the inverter circuit 42. Further, the detection signals from the plurality of Hall elements 41a to 41c are sent to the external rotor position detection circuit 46. Electric power is supplied to each of the Hall elements 41a to 41c from the outside.

6 is a plan view showing the inner surface of the bracket shown in FIG. 1, FIG. 7 is a plan view showing the wiring provided on the bracket, and FIG. 8 is a perspective view of FIG. 7.

As shown in FIG. 7, three power wirings 51 to 53 are arranged in the bracket 13. Each of the power wirings 51 to 53 energizes the coil 35 with the electric power output from the inverter circuit 42. Sensor wirings 54 to 56 are arranged in the bracket 13. Each sensor wiring transmits the output signals of the Hall elements 41a to 41c to the rotor position detection circuit 46. In the bracket 13, a wiring 57 for a power supply as a power feeding wiring and a wiring 58 for a ground are arranged. Power is supplied from the power supply wiring 57 to the detection sensors such as the Hall elements 41a to 41c provided on the sensor board 39.

Internal terminals 51a to 53a are provided at one end of the power wirings 51 to 53. Each of the internal terminals 51a to 53a is bent in a direction perpendicular to the power wiring 51 to 53 toward the tip end side of the shaft 18. The three internal terminals 51a to 53a are arranged along the outer peripheral surface of the flange portion 26 of the bearing holder 24 at intervals. A part of the portion of the internal terminals 51a to 53a along the axial direction is arranged at a position overlapping the part of the flange portion 26 in the radial direction. FIG. 2 shows the power wiring 52 and its internal terminal 52a, and the internal terminal 52a is connected to the coil terminal 37. Similarly, the internal terminals 51a and 53a of the other power wirings 51 and 53 are connected to the other coil terminals. In this way, the internal terminals 51a to 53a of the power wirings 51 to 53 are connected to the three-phase coil terminals 37, and power is supplied to each coil 35 via the power wirings 51 to 53. The power wirings 51 to 53 extend radially with respect to the central portion of the bearing holder 24, and external terminals 51b to 53b are provided at the other end portions of the power wirings 51 to 53.

Internal terminals 54a to 56a are provided at one end of the sensor wirings 54 to 56. The internal terminals 54a to 56a are bent in a direction perpendicular to the sensor wirings 54 to 56 toward the base end portion side of the shaft 18. The internal terminals 54a to 56a are connected to the Hall elements 41a to 41c, and their respective detection signals are sent to the rotor position detection circuit 46 via the sensor wirings 54 to 56. In FIG. 2, one sensor wiring 55 is shown, and the sensor wirings 54 to 56 are axially displaced toward the proximal end portion of the shaft 18 from the power wirings 51 to 53, and in FIG. It is shifted upward from the power wiring 51 to 53. External terminals 54b to 56b are provided at the other ends of the sensor wirings 54 to 56, and the respective external terminals 54b to 56b are parallel to the external terminals 51b to 53b of the power wirings 51 to 53. The respective internal terminals 54a to 56a are displaced in the circumferential direction of the bearing holder 24 with respect to the internal terminals 51a to 53a of the power wirings 51 to 53, and the sensors between the internal terminals 54a to 56a and the external terminals 54b to 56b. The portions of the wirings 54 to 56 meander.

Internal terminals 57a and 58a are provided at one end of the power supply wiring 57 and the ground wiring 58. The internal terminals 57a and 58a are bent in a direction perpendicular to the power supply wiring 57 and the ground wiring 58 toward the base end side of the shaft 18. Each of the internal terminals 57a and 58a is connected to a terminal (not shown) on the board side provided on the sensor board 39, and power is supplied to an element or the like provided on the sensor board 39. In FIG. 2, the wiring 57 for the power supply is shown, and the wirings 57 and 58 for the power supply and the ground are displaced from the power wirings 51 to 53 toward the tip of the shaft 18, and in FIG. It is shifted below the power wiring 51 to 53. A part of each of the internal terminals 57a and 58a along the axial direction is arranged at a position overlapping with a part of the flange portion 26 in the radial direction. As shown in FIG. 8, external terminals 57b and 58b are provided at the other ends of the power supply and ground wirings 57 and 58, and the external terminals 57b and 58b are power wirings 51 to 53, respectively. The external terminals 51b to 53b of the above are parallel to the external terminals 54b to 56b of the sensor wirings 54 to 56.

As shown in FIG. 5, the bracket 13 is provided with a connector 47. The connector 47 has a resin cylindrical portion 48. External terminals 51b to 53b of the power wirings 51 to 53 project from the bottom surface of the connector 47, and these are arranged in a straight line with each other. External terminals 54b to 56b of the sensor wirings 54 to 56 project from the bottom surface of the connector 47 to the lower side in FIG. 5 with respect to the external terminals 51b to 53b, and these are arranged in a straight line with each other. Further, the external terminals 57b and 58b of the wirings 57 and 58 for power supply and ground protrude from the bottom surface of the connector 47, and are arranged on the upper side in FIG. 5 with respect to the external terminals 51b to 53b.

A connection plug (not shown) is attached to the connector 47, and the cable of the connection plug is connected to all the external terminals 51b to 58b. As a result, electric power is supplied from the inverter circuit 42 to each coil 35 at a predetermined timing, and the detection signals of the Hall elements 41a to 41c are transmitted to the rotor position detection circuit 46. Further, power is supplied from the power supply wiring 57 to the detection sensors such as the Hall elements 41a to 41c provided on the sensor board 39.

As shown in FIG. 7, a reference line extending radially from the center point O of the bearing holder 24, that is, the center point O of the cylindrical portion 25, and passing through the circumferential center portion of the three internal terminals 51a to 53a. The reference line P1 is defined as the second reference line P2, which extends radially from the center point O and passes through the circumferential central portion of the three internal terminals 54a to 56a, and extends radially from the center point O. The reference line passing through the central portion of the two internal terminals 57a and 58a in the circumferential direction is referred to as a third reference line P3. The angle α formed by the first reference line P1 and the second reference line P2 and the angle β formed by the first reference line P1 and the third reference line P3 are about 60 degrees, respectively, and the second reference line P2 and the second reference line P2 are formed. The angle formed by the three reference lines P3, that is, the angle γ (γ = α + β) at which the internal terminals 54a to 56a and the internal terminals 57a and 58a are separated in the circumferential direction is about 120 degrees, and is 90 degrees to 180 degrees. It is an obtuse angle in the range of degrees. The center point O indicates a point where the central axis of the cylindrical portion 25 intersects with a plane or a straight line in a direction perpendicular to the central axis.

In this way, the internal terminals 54a to 56a of the sensor wiring and the internal terminals 57a and 57b for the power supply and the ground as the power supply wiring are distributed and arranged in the circumferential direction with respect to the flange portion 26 of the bearing holder 24. Will be done. As a result, the diameter of the flange portion 26 can be reduced without complicating the circuit pattern of the sensor board 39 as compared with the case where these internal terminals 54a to 58a are collectively arranged, and the motor can be miniaturized. Can be done.

Sensor wiring 54 to 56 and wirings 57 and 58 for power supply and ground so that the external terminals 54b to 56b and the external terminals 57b and 58b are gathered at substantially the same portion in the circumferential direction of the flange portion 26. Is routed toward the external terminals 51b to 53b in the space outside the radial direction of the flange portion 26 of the bearing holder 24, so that all the external terminals 51b to 58b can be arranged in one connector 47. As a result, all external terminals can be connected by inserting one connection plug into the connector 47. However, if the bracket 13 is provided with a connector provided with external terminals 51b to 53b of the power wirings 51 to 53 and a connector provided with other external terminals 54b to 58b, the bracket 13 has two connectors.

As shown in FIGS. 7 and 8, all the wirings 51 to 58 described above are insert-molded into the resin wiring holding block 61 by preforming. Next, during the main molding for molding the bracket 13, the preformed, that is, the premolded wiring holding block 61 and the bearing holder 24 are insert-molded into the bracket 13. FIG. 6 shows the inner surface of the insert-molded bracket 13.

As shown in FIG. 8, the wiring holding block 61 has a preforming portion 62 in which the wiring 57 for the power supply and the wiring 58 for the ground are insert-molded, and a preforming portion 63 in which the sensor wirings 54 to 56 are insert-molded. And have. The preformed portion 62 includes an external terminal holding portion 62a, a wiring holding portion 62b, and an internal terminal holding portion 62c. The external terminals 57b and 58b protrude from the external terminal holding portion 62a, and the internal terminals 57a and 58a are internal terminal holding portions. It protrudes from 62c. On the other hand, the preforming portion 63 has a first wiring holding portion 63a and a second wiring holding portion 63b, and the external terminal holding portion 63c is integrated with the first wiring holding portion 63a to form a second wiring. An internal terminal holding portion 63d is integrated with the holding portion 63b. The external terminals 54b to 56b protrude from the external terminal holding portion 63c, and the internal terminals 54a to 56a protrude from the internal terminal holding portion 63d.

Window portions 64a to 64c are formed in the premolded portions 62 and 63, respectively, and each of the window portions is formed by a positioning jig for positioning the wiring at the time of preforming. The power wiring 51 is arranged between both preformed portions 62, 63.

Four holes 65a to 65d are formed in the external terminal holding portion 63c of the preforming portion 63 by a pin provided in a mold for preforming. The pins forming the three holes 65a to 65c abut on the three sensor wirings 54 to 56 during preforming to position the wirings. When the preformed wiring holding block 61 is placed in the molding die and the bracket 13 is main-molded together with the bearing holder 24, the wiring holding block 61 is placed in the two holes 65c and 65d in the main molding die. A pin for positioning is inserted.

FIG. 9 is a plan view showing the arrangement relationship between the flange portion of the bearing holder and each inner terminal. As shown in FIGS. 7 and 9, assuming that the maximum outer diameter of the flange portion 26 of the bearing holder 24 is R1, the facing surfaces 71 of the flange portions 26 facing the internal terminals 51a to 53a of the power wirings 51 to 53 Is formed by an arc surface shape having an outer diameter R2 smaller than the maximum outer diameter R1. As described above, the facing surface 71 is formed by an arc surface having a radius R2 having a diameter smaller than the maximum outer diameter by providing a notch portion in the flange portion 26.

The internal terminal holding portion 63d of the preformed portion 63 is arranged at a position deviated by an angle α in the circumferential direction with respect to the facing surface 71, and abuts on the inner surface of the flange portion 26. As shown in FIG. 9, a straight line portion 72 is provided on the outer peripheral surface of the flange portion 26 as a terminal arrangement portion for the sensor, and the internal terminals 54a to 56a provided in the internal terminal holding portion 63d are straight line portions 72. It is placed along. In the terminal arrangement portion composed of the straight line portion 72, the distance from the center point O, that is, the point on the central axis of the cylindrical portion 25 changes from one end to the other end in the circumferential direction, and the distance from the center point O of the terminal arrangement portion changes. The distance is smaller than the maximum radius R1 of the flange portion 26.

As shown in FIGS. 8 and 9, the internal terminal holding portion 63d is provided with a facing surface 73 extending along the straight line portion 72. Therefore, when the premolded portion 63 is insert-molded into the bracket 13 by the main molding, the resin enters between the straight portion 72 and the facing surface 73, and the resin material of the bracket 13 is formed in the straight portion 72 of the flange portion 26. In close contact. As a result, even if the flange portion 26 receives an external force in the direction of rotation with respect to the resin bracket 13 due to vibration applied to the motor, the flange portion 26 is prevented from shifting and moving with respect to the bracket 13, and the durability of the motor is maintained. The sex is enhanced.

The terminal arrangement portion is formed by a straight portion 72, but if the terminal arrangement portion is an arc portion having the same radius as the whole distance from the center point O from one end to the other end, the motor may be used. When the flange portion 26 receives an external force in the direction of rotation with respect to the bracket 13 due to the applied vibration, the flange portion 26 may be displaced with respect to the bracket 13. However, if the flange portion 26 is provided with a terminal arrangement portion such as a straight portion whose distance from the center point O changes from one end to the other end, the flange portion 26 shifts with respect to the bracket 13. Can be prevented.

The internal terminal holding portion 62c of the preformed portion 62 is arranged at a position deviated by an angle γ (α + β) in the circumferential direction with respect to the internal terminal holding portion 63d, and abuts on the inner surface of the flange portion 26. As shown in FIG. 9, a straight line portion 74 is provided on the outer peripheral surface of the flange portion 26 as a terminal arrangement portion for power supply, and the internal terminals 57a and 58a provided in the internal terminal holding portion 62c are straight line portions 74. It is placed along. Similar to the straight line portion 72, the terminal arrangement portion composed of the straight line portion 74 changes the distance from the center point O from one end to the other end in the circumferential direction, and the distance from the center point O of the terminal arrangement portion is It is smaller than the maximum radius R1 of the flange portion 26. On the other hand, the internal terminal holding portion 62c is also formed with a facing surface 75 extending along the straight line portion 74.

Therefore, when the premolded portion 62 is insert-molded into the bracket 13 by the main molding, the resin enters between the straight portion 74 and the facing surface 75, and the straight portion 74 of the flange portion 26 is the same as the straight portion 72. The resin material of the bracket 13 is in close contact with the metal. As a result, even if the flange portion 26 receives an external force in the direction of rotation with respect to the resin bracket 13 due to the vibration applied to the motor, the flange portion 26 is prevented from shifting and moving with respect to the bracket 13.

As each terminal arrangement portion, a straight portion is preferable from the viewpoint of ease of processing of the bearing holder 24, but an arcuate surface shape having a radius not centered on the center point O may be used, or a concave surface shape portion may be used.

A straight line portion 72a for stress relief is formed on the outer peripheral surface of the flange portion 26 located on the opposite side of the straight line portion 72 in the radial direction as a similar shape portion to the straight line portion 72, and the straight line portion 72a is a straight line portion. It is parallel to the part 72. Similarly, a straight portion 74a for stress relaxation parallel to the straight portion 74 is formed on the outer peripheral surface of the flange portion 26 located on the opposite side in the radial direction of the straight portion 74, and the straight portion 74a has a similar shape portion. Is forming. The two straight lines 72 and 74 as the terminal arrangement parts are offset by an angle γ in the circumferential direction and are set to an obtuse angle of 180 degrees or less, so that the straight lines 72 and 74 are on opposite sides in the radial direction. The straight portions 72a and 74a can be provided.

In this way, if the straight portions 72a and 74a for stress relaxation are provided so as to be located on the opposite sides of the straight portions 72 and 74 in the radial direction, the roundness of the cylindrical portion 25 is rounded even after the bearing holder 24 is machined. Can be retained. When the metal plate is drawn and the cylindrical portion 25 and the flange portion 26 are plastically worked, residual stress is generated in the entire bearing holder 24 including the flange portion 26 during the plastic working. When either or both of the two straight portions 72 and 74 are cut on the flange portion 26 after the plastic working, the residual stress is concentrated on the cut straight portion to become a stress concentration portion. The stress concentration portion is easily deformed and may affect the roundness of the cylindrical portion 25.

On the other hand, when the straight portions 72a and 74a as similar figures for stress relaxation are formed on the opposite sides of the linear portions 72 and 74 in the radial direction, the roundness of the cylindrical portion 25 is secured and the roundness of the cylindrical portion 25 is secured. Durability can be improved.

As shown by the two-dot chain line in FIG. 9, an arc surface 71a as a similar shape portion to the facing surface 71 may be formed on the opposite side in the radial direction of the facing surface 71. In that case, the facing surface 71 may be formed. Stress concentration can be relaxed.

FIG. 6 shows the inner surface of the bracket 13 in a state where the resin bracket 13 is molded by the main molding. When the wiring holding block 61 including the preformed portions 62 and 63 and the bearing holder 24 are insert-molded into the bracket 13, an opening that exposes the internal terminals 51a to 53a to the inside by the resin material of the bracket 13. 81 is formed on the bracket 13. Further, a cylindrical hole 82 is formed inside the bracket 13, and a portion of the flange portion 26 of the bearing holder 24 inside the cylindrical hole 82 is exposed inside the bracket 13. The internal terminal holding portions 62c and 63d are incorporated inside the bracket 13, leaving the terminal protruding surface. In FIG. 6, reference numeral 83 is a through hole formed in the bearing holder 24, and the shaft 18 penetrates the through hole 83. Reference numeral 84 is an inner peripheral surface of the cylindrical portion 25 of the bearing holder 24.

Therefore, the outer peripheral surface of the flange portion 26 is embedded inside the bracket 13, and the resin material of the bracket 13 is in close contact with the straight portions 72, 72a, 74, 74a, respectively. As a result, the flange portion 26 is firmly fixed to the bracket 13.

The present invention is not limited to the above embodiment, and various modifications can be made without departing from the gist thereof.

11 Motor case 13 Bracket 15 Stator 16 Rotor 18 Shaft 21, 22 Bearing 24 Bearing holder 25 Cylindrical part 26 Flange part 31 Ring magnet 35 Coil 36 Busbar unit 37 Coil terminal 39 Sensor board 41a to 41c Hall element 47 Connector 51 to 53 Power wiring 51a to 53a Internal terminals 51b to 53b External terminals 54 to 56 Sensor wiring 54a to 56a Internal terminals 54b to 56b External terminals 57 Power supply wiring 58 Ground wiring 57a, 58a Internal terminals 57b, 58b External terminals 61 Wiring holding blocks 62, 63 Pre-molded portion 71 Facing surface 72, 72a Straight portion 73 Facing surface 74, 74a Straight portion 75 Facing surface

Claims (8)

A stator fixed inside a motor case having a bottomed cylinder, a rotor rotatably supported inside the stator with a shaft supported by bearings, and attached to the axial end of the motor case. A brushless motor comprising a resin bracket to be made of bearing and a bearing holder having a cylindrical portion for holding the bearing and being insert-formed into the bracket.
A flange portion provided in the bearing holder in connection with the cylindrical portion and extending outward in the radial direction, and a flange portion.
A sensor board on which a plurality of detection sensors for detecting the rotational position of the rotor are mounted, and
It has a sensor wiring that sends an output signal from the detection sensor.
A terminal arrangement portion for a sensor whose distance from the center point changes from one end to the other end is provided on the outer peripheral surface of the flange portion.
A brushless motor in which the internal terminals of the sensor wiring are arranged along the terminal arrangement portion. In the brushless motor according to claim 1,
It has power supply wiring for power supply and ground to supply power to the detection sensor.
The terminal arrangement portion for power supply whose distance from the center point changes from one end to the other end is shifted in the circumferential direction at an obtuse angle with respect to the terminal arrangement portion for the sensor, and the outer peripheral surface of the flange portion is formed. Provided in
A brushless motor in which the internal terminals of the power supply wiring are arranged along the terminal arrangement portion for power supply. In the brushless motor according to claim 1 or 2.
A similar shape portion for residual stress relaxation is provided on the outer peripheral surface of the flange portion located on the opposite side of the terminal arrangement portion in the radial direction to relax the residual stress generated in the bearing holder when the bearing holder is machined. Also, a brushless motor. In the brushless motor according to claim 2,
It has a power wiring that supplies power to the coil provided in the stator.
The internal terminals of the power wiring are arranged between the terminal arrangement portion for the sensor and the terminal arrangement portion for power supply.
A brushless motor in which a facing surface facing the internal terminals of the power wiring is formed on the flange portion by a notch portion. In the brushless motor according to claim 4,
A notch for stress relaxation for relieving residual stress that relieves residual stress generated in the bearing holder when the bearing holder is machined on the outer peripheral surface of the flange portion located on the opposite side in the radial direction of the facing surface. Brushless motor with a part. In the brushless motor according to claim 2,
A connector is provided on the bracket,
A brushless motor in which an external terminal of the sensor wiring and an external terminal of the power feeding wiring are provided in the connector. In the brushless motor according to claim 4,
A connector is provided on the bracket,
A brushless motor in which an external terminal of the sensor wiring, an external terminal of the power feeding wiring, and an external terminal of the power wiring are provided in the connector. The brushless motor according to any one of claims 1 to 7.
The terminal arrangement portion is a straight line portion, which is a brushless motor.

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