JP2021048661A - Brushless motor - Google Patents

Abstract

To realize downsizing and reduction in weight by simplifying a shape and an arrangement structure of a magnetism transfer member and to make high-accurate control possible.SOLUTION: Hall elements 81a, 81b and 81c are disposed side by side at a predetermined spacing S3 on a line segment LN1 orthogonal to an axis (rotation center C) of a first sensor magnet MG1 radially outside of the first sensor magnet MG1. Magnetism transfer members 101, 102 and 103 comprise: first magnetism transfer parts 101a, 102a and 103a opposed to an end face EM1 of the first sensor magnet MG1; second magnetism transfer parts 101b, 102b and 103b opposed to detection surfaces of the Hall elements 81a, 81b and 81c; and third magnetism transfer parts 101c, 102c and 103c connecting the first magnetism transfer parts 101a, 102a and 103a with the second magnetism transfer parts 101b, 102b and 103b.SELECTED DRAWING: Figure 9

Description

The present invention relates to a brushless motor including a stator, a rotor rotatably provided with respect to the stator, and a rotating shaft fixed to the center of rotation of the rotor.

Conventionally, a motor with a reduction mechanism that can obtain a large output while being small has been adopted as a drive source of a wiper device or the like mounted on a vehicle such as an automobile, thereby improving the mountability on the vehicle. Further, in order to suppress the propagation of electromagnetic noise to an in-vehicle device such as a radio, a brushless motor without a commutator and a brush may be adopted for the motor unit. In this way, by adopting a brushless motor for the motor section, it is possible not only to suppress the generation of electromagnetic noise, but also to make it smaller and lighter because it is not provided with a commutator or a brush.

In such a brushless motor, an annular magnet is fixed on the outer circumference of the rotating shaft, and the rotating state of the magnet is detected by a plurality of Hall elements. As a result, the controller can control the rotation speed, rotation direction, etc. (rotation state) of the rotation shaft by sequentially energizing the multi-phase coils at the optimum timing while grasping the rotation state of the rotation shaft.

Further, the brushless motor mounted on the vehicle is desired to be further reduced in size and weight, which makes it difficult to lay out the magnet fixed to the rotating shaft and the Hall element mounted on the substrate. In some cases.

For example, in the technique described in Patent Document 1, a substantially rectangular substrate is arranged so as to extend outward in the radial direction of the magnet. A total of three magnetic transmission members formed in an elongated plate shape are arranged between the magnet and the Hall element mounted on the substrate. Therefore, the change in magnetism accompanying the rotation of the magnet is transmitted to the Hall element at a predetermined timing.

Special Table 2001-506368 Gazette

However, in the technique described in Patent Document 1 described above, each of the three magnetic transmission members in total is bent into a complicated shape and set to a relatively long size. Therefore, there has been a problem that it is difficult to mold each magnetic transmission member, it is difficult to improve the magnetic transmission efficiency, and it is difficult to further reduce the size and weight of the entire brushless motor.

An object of the present invention is to provide a brushless motor that can be controlled with high accuracy while simplifying the shape and arrangement structure of the magnetic transmission member to realize compactness and weight reduction.

In one aspect of the present invention, a brushless motor including a stator, a rotor rotatably provided with respect to the stator, and a rotation shaft fixed to the rotation center of the rotor, the rotation shaft thereof. An annular magnet that is fixed and has a plurality of magnetic poles arranged alternately in the rotation direction of the rotation axis, and a plurality of magnetic transmission members that are provided in a state in which the magnets generated by the magnets are transmitted and are not in contact with each other. It has a plurality of rotation sensors for detecting the magnetism transmitted to the plurality of magnetic transmission members, and the plurality of rotation sensors are on a line segment orthogonal to the axis of the magnet on the radial outer side of the magnet. The plurality of magnetic transmission members are provided side by side at predetermined intervals, and the plurality of magnetic transmission members are a first magnetic transmission unit facing the axial end surface of the magnet and a second magnetic transmission facing the detection surface of the rotation sensor. It is characterized by including a unit and a third magnetic transmission unit that connects the first magnetic transmission unit and the second magnetic transmission unit.

In another aspect of the present invention, the first magnetic transmission unit is arranged in a range of 180 degrees on the axial end surface of the magnet on the side where the rotation sensor is provided. ..

In another aspect of the present invention, of the plurality of magnetic transmission members, the volume of the magnetic transmission member provided on the side where the distance between the magnet and the rotation sensor is longer is larger than the volume of the magnet and the rotation. It is characterized in that the distance from the sensor is larger than the volume of the magnetic transmission member provided on the shorter side.

In another aspect of the present invention, the three rotation sensors are mounted side by side on the substrate, and the distance between the pair of rotation sensors arranged on both sides of the three rotation sensors arranged side by side is large. It is characterized in that it is larger than the outer diameter dimension of the magnet.

In another aspect of the present invention, the magnet is provided with four poles of magnetic poles having different polarities alternately in the circumferential direction, and the magnetic transmission member is wound around the stator in U-phase and V-phase. It is characterized in that three are provided corresponding to the W-phase coil.

In another aspect of the present invention, the rotation sensor is a Hall element.

Another aspect of the present invention is further characterized in that an output shaft rotated by the rotating shaft is provided, and the output shaft swings the wiper member.

According to the present invention, a plurality of rotation sensors are provided side by side at predetermined intervals on a line segment orthogonal to the axis of the magnet on the outer side in the radial direction of the magnet, and the plurality of magnetic transmission members are the axes of the magnet. A first magnetic transmission unit facing one end surface in the direction, a second magnetic transmission unit facing the detection surface of the rotation sensor, and a third magnetic transmission unit connecting the first magnetic transmission unit and the second magnetic transmission unit. Each has.

Therefore, the first magnetic transmission portion of the magnetic transmission member can be opposed to one end surface in the axial direction of the magnet, and the magnet and the rotation sensor can be arranged closer to each other than before. Therefore, the shape and arrangement structure of the magnetic transmission member can be simplified, and the entire brushless motor can be reduced in size and weight.

Further, since the shape of the magnetic transmission member can be simplified, it is possible to improve the transmission efficiency of the magnetism transmitted through the magnetic transmission member, and it is possible to control the brushless motor with higher accuracy.

It is a figure which mounts a wiper motor on a vehicle. It is a top view of the wiper motor seen from the output shaft side. It is a top view of the wiper motor seen from the cover member side. It is a perspective view explaining the internal structure of the reduction mechanism accommodating part. It is an exploded perspective view which shows a cover member, a substrate, and a substrate cover. It is a perspective view which shows the inside of a cover member. It is a perspective view which shows the back side of a substrate. It is a perspective view explaining the structure of a magnetic transmission member. It is a figure which looked at the 1st sensor magnet, 3 magnetic transmission members, and 3 Hall elements from the direction of arrow A of FIG. It is a B arrow view of FIG. (A) is a graph showing the relationship between the separation distance between the sensor magnet and the Hall element and the magnetic flux density, and (b) is a graph showing the relationship between the separation distance between the sensor magnet and the Hall element and the volume of the magnetic transmission member.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a view of mounting the wiper motor on a vehicle, FIG. 2 is a plan view of the wiper motor viewed from the output shaft side, FIG. 3 is a plan view of the wiper motor viewed from the cover member side, and FIG. 4 is a reduction mechanism accommodating portion. 5 is an exploded perspective view showing the cover member, the substrate, and the substrate cover, FIG. 6 is a perspective view showing the inside of the cover member, and FIG. 7 is a perspective view showing the back side of the substrate. FIG. 8 is a perspective view for explaining the structure of the magnetic transmission member, and FIG. 9 is a view of the first sensor magnet, the three magnetic transmission members, and the three Hall elements as viewed from the direction of arrow A in FIG. 9A is a view taken along the line B of FIG. 9, FIG. 11A is a graph showing the relationship between the distance between the sensor magnet and the Hall element and the magnetic flux density, and FIG. 11B is the distance and magnetic transmission between the sensor magnet and the Hall element. Graphs showing the relationship between the volumes of the members are shown.

As shown in FIG. 1, in the present embodiment, a brushless motor is adopted as a drive source of the wiper device. Specifically, a front windshield 11 is provided on the front side of a vehicle 10 such as an automobile. A wiper device 12 for wiping rainwater, dust, etc. adhering to the front windshield 11 is mounted on the front end portion of the front windshield 11 of the vehicle 10. The wiper device 12 includes a pair of wiper arms 13 on the driver's seat side (right side in the drawing) and the passenger seat side (left side in the drawing), and further includes one wiper motor (brushless motor) 20.

The wiper motor 20 is connected to the base end side of the pair of wiper arms 13 via a link mechanism 14, whereby the pair of wiper blades 15 provided on the tip side of the pair of wiper arms 13 are placed on the front windshield 11. Each is oscillated. Here, the vehicle 10 shown in FIG. 1 is a vehicle having a right-hand drive specification, and the wiper device 12 is arranged at a portion closer to the driver's seat along the vehicle width direction of the vehicle 10.

The wiper motor 20 is a so-called reversing wiper motor of a forward / reverse rotation type that alternately performs forward rotation and reverse rotation based on a predetermined control logic. As a result, the wiper motor 20 repeats forward and reverse rotation, so that the link mechanism 14 reciprocates in the left-right direction in the drawing, and the pair of wiper arms 13 and the pair of wiper blades 15 reciprocate and wipe over the pair of wiping ranges 16. Operate. Therefore, rainwater, dust, and the like adhering to the front windshield 11 are wiped off cleanly.

As shown in FIGS. 2 to 4, the wiper motor 20 is a motor device with a speed reduction mechanism, and is a cover that closes the housing 30 that houses the motor 60 and the speed reduction mechanism 70 and the first opening OP of the housing 30. It includes a member 40 and a motor cover 50 that closes a second opening (not shown) of the housing 30. The housing 30, the cover member 40, and the motor cover 50 form an outer shell of the wiper motor 20 in a state of being assembled from each other.

The housing 30 includes a speed reduction mechanism accommodating portion 31 formed in a predetermined shape by casting and molding a molten aluminum material or the like, and formed in a substantially bathtub shape with a bottom. Further, the housing 30 is integrally provided with the speed reduction mechanism accommodating portion 31, and includes a motor fixing portion 32 formed in a bottomed substantially cylindrical shape.

One side of the motor fixing portion 32 in the axial direction is connected to the side wall 31b of the reduction mechanism accommodating portion 31, and the first through hole 31e through which the rotation shaft 64 of the motor 60 (see FIG. 2) penetrates the side wall 31b. And a second through hole 31f through which the motor-side terminal portion 62a of the terminal holder 62 forming the motor 60 penetrates are formed.

A second opening (not shown) is formed on the other side of the motor fixing portion 32 in the axial direction, and the motor 60 is assembled from the second opening to the inside of the motor fixing portion 32. Specifically, the stator 61 (see FIG. 2) forming the motor 60 is fixed radially inside the motor fixing portion 32, and a predetermined gap is formed inside the stator 61 fixed to the motor fixing portion 32 in the radial direction. The rotor 63 is rotatably housed via the rotor 63. Approximately half of the stator 61 on one side in the axial direction is fixed to the inside of the motor fixing portion 32 in the radial direction by press fitting.

An annular flange portion 32a projecting outward in the radial direction is integrally provided on the other side of the motor fixing portion 32 in the axial direction. An annular cover flange 52 provided on the side opposite to the bottom 51 side along the axial direction of the motor cover 50 is in contact with the flange portion 32a. The flange portion 32a and the cover flange 52 are fixed to each other by a pair of fastening screws SC1 (only one is shown in the figure). As a result, substantially half of the stator 61 on the other side in the axial direction is covered with the motor cover 50. The stator 61 is in a non-contact state with respect to the motor cover 50, which makes it possible to easily attach the motor cover 50 to the motor fixing portion 32.

Here, a sealing member such as a sealing agent is provided between the cover flange 52 and the flange portion 32a. This prevents the motor 60 from being exposed to water. Further, an uneven portion (not shown) is formed in the central portion of the bottom portion 51, whereby the rigidity of the bottom portion 51 is increased. Therefore, the resonance of the bottom portion 51 during operation of the motor 60 is suppressed, and the quietness of the wiper motor 20 is improved.

As shown in FIG. 2, the motor 60 housed inside the motor fixing portion 32 and the motor cover 50 includes a stator (stator) 61 fixed inside the motor fixing portion 32 in the radial direction. The stator 61 is formed in a substantially tubular shape by laminating a plurality of magnetic steel plates, and a plurality of teeth (not shown) are provided inside the stator 61 in the radial direction. A U-phase, V-phase, and W-phase (three-phase) coils (not shown) are wound around these teeth by, for example, a winding method such as delta connection.

Further, as shown in FIG. 4, a terminal holder 62 made of an insulating material such as plastic is mounted on one side of the stator 61 in the axial direction. The terminal holder 62 aggregates the three-phase coils wound around the stator 61 and pulls out the ends of the coils to the outside. The terminal holder 62 includes a motor-side terminal portion 62a, and the motor-side terminal portion 62a penetrates a second through hole 31f provided in the side wall 31b. As a result, the end portion of the three-phase coil is pulled out to the outside of the motor fixing portion 32 (inside the reduction mechanism accommodating portion 31).

Here, the motor-side terminal portion 62a is formed in a hollow substantially box shape, and inside the terminal portion 62a, three female terminals TM1, TM2, and TM3 are crimped and fixed to the ends of the three-phase coils. It is provided. The female terminal TM1 corresponds to the U-phase coil, the female terminal TM2 corresponds to the V-phase coil, and the female terminal TM3 corresponds to the W-phase coil.

As shown in FIG. 2, a rotor (rotor) 63 is rotatably housed inside the stator 61 through a predetermined gap. That is, the rotor 63 is rotatably provided with respect to the stator 61. The rotor 63 is formed in a substantially columnar shape by laminating a plurality of steel plates which are magnetic materials. A permanent magnet (not shown) formed in a substantially cylindrical shape is attached to the outer peripheral portion of the rotor 63.

As described above, the wiper motor 20 employs a brushless motor having an SPM (Surface Permanent Magnet) structure in which a permanent magnet is mounted on the surface of the rotor 63. However, the brushless motor having an SPM structure is not limited to the brushless motor having an IPM (Interior Permanent Magnet) structure in which a plurality of permanent magnets are embedded in the rotor 63. Further, instead of one permanent magnet formed in a substantially cylindrical shape, a plurality of permanent magnets having a cross-sectional shape formed in a substantially arc shape in the direction intersecting the axis of the rotor 63 are provided with magnetic poles in the circumferential direction of the rotor 63. Those arranged at equal intervals so as to be arranged alternately may be adopted. Further, the number of poles of the permanent magnet can be arbitrarily set, such as 2 poles or 4 poles or more, depending on the specifications required for the wiper motor 20.

As shown in FIG. 2, the base end side of the rotation shaft 64 is fixed to the rotation center of the rotor 63. Further, a worm 71 (see FIG. 4) formed by rolling or the like is integrally provided on the tip end side of the rotating shaft 64. Here, the worm 71 constitutes the deceleration mechanism 70 together with the worm wheel 72 housed in the deceleration mechanism accommodating portion 31.

As shown in FIG. 4, a bearing member BE is provided at a substantially intermediate portion along the axial direction of the rotating shaft 64, and the bearing member BE is mounted inside the reduction mechanism accommodating portion 31. The bearing member BE rotatably supports the rotating shaft 64 and restricts the movement of the rotating shaft 64 in the axial direction. Therefore, the bearing member to be provided on the base end side of the rotating shaft 64 is omitted. On the other hand, a bearing member (not shown) smaller than the bearing member BE is provided on the tip end side of the rotating shaft 64 in order to suppress the runout of the worm 71. In this way, by omitting the bearing member on the base end side of the rotary shaft 64 and providing a small bearing member on the tip end side of the rotary shaft 64, the dimensions along the axial direction of the rotary shaft 64 of the wiper motor 20 are reduced. , Compact and lightweight.

Further, an annular first sensor magnet (magnet) MG1 is provided between the worm 71 along the axial direction of the rotating shaft 64 and the bearing member BE. The first sensor magnet MG1 is fixed to the outside of the rotating shaft 64 in the radial direction. The first sensor magnet MG1 is provided with a plurality of magnetic poles (N pole, S pole) having different polarities arranged alternately along the rotation direction of the rotation shaft 64. Specifically, the first sensor magnet MG1 is a permanent magnet in which four poles are arranged at 90-degree intervals in the circumferential direction (see FIG. 9).

Then, the first sensor magnet MG1 is rotated together with the rotation shaft 64, whereby the magnetic poles of the first sensor magnet MG1 appear alternately with the rotation of the rotation shaft 64. A total of three magnetic transmission members 101, 102, and 103 are interposed on the outer side of the first sensor magnet MG1 in the radial direction and on the portion of the substrate 80 (see FIGS. 5 and 7) facing the first sensor magnet MG1. A total of three Hall elements (rotation sensors) 81a, 81b, 81c (see FIG. 9) are arranged. As a result, the rotation speed, rotation direction, and the like (rotational state) of the rotation shaft 64 are detected by the three Hall elements 81a, 81b, and 81c.

Further, as shown in FIG. 10, the Hall elements 81a, 81b, and 81c have a size within the width dimension W of the first sensor magnet MG1. As a result, the magnetism from the first sensor magnet MG1 can be detected via the three magnetic transmission members 101, 102, 103 without the three Hall elements 81a, 81b, 81c varying. The Hall element is a sensor that measures the magnetic flux density using the Hall effect.

As shown in FIGS. 2 and 4, the speed reduction mechanism accommodating portion 31 includes a bottom wall 31a and a side wall 31b provided so as to surround the bottom wall 31a. More specifically, the side wall 31b is provided so as to rise at a substantially right angle from the bottom wall 31a.

A worm wheel 72 made of a resin material such as plastic is rotatably housed inside the speed reduction mechanism accommodating portion 31. The base end side of the output shaft 73 is fixed to the center of rotation of the worm wheel 72, and the tip end side of the output shaft 73 extends to the outside of the housing 30 via a boss portion 31c provided on the bottom wall 31a. ing. That is, the extending direction of the output shaft 73 and the extending direction of the rotating shaft 64 are orthogonal to each other. A fixed washer WS is mounted on the tip end side of the output shaft 73, whereby the output shaft 73 is fixed to the boss portion 31c (housing 30) in the axial direction. A link mechanism 14 (see FIG. 1) is fixed to the tip end side of the output shaft 73.

Gear teeth 72a (not shown in detail) are formed on the outer peripheral portion of the worm wheel 72, and the worm 71 integrally provided on the rotating shaft 64 is meshed with the gear teeth 72a. Here, the worm 71 and the worm wheel 72 form a deceleration mechanism 70, and the deceleration mechanism 70 decelerates the rotation of the rotating shaft 64 to a predetermined rotation speed to increase the torque, and the rotation is increased in torque. The force is output from the output shaft 73 to the link mechanism 14. That is, the output shaft 73 is rotated by the rotation of the rotation shaft 64, and the output shaft 73 swings the wiper member including the wiper arm 13 and the wiper blade 15 via the link mechanism 14.

Further, as shown in FIG. 4, the second sensor magnet MG2 is fixed at the center of rotation of the worm wheel 72 and on the side opposite to the output shaft 73 side. The second sensor magnet MG2 is provided with a plurality of magnetic poles (N pole, S pole) having different polarities side by side along the rotation direction of the output shaft 73 (see FIG. 2). As a result, the magnetic poles of the second sensor magnet MG2 appear alternately as the output shaft 73 rotates. Then, one MR sensor 82 is provided on the portion of the substrate 80 (see FIGS. 5 and 7) facing the second sensor magnet MG2. As a result, the MR sensor 82 detects the rotation direction, rotation position, and the like (rotational state) of the output shaft 73.

As shown in FIG. 2, a total of three mounting legs 31d are provided on the bottom wall 31a of the speed reduction mechanism accommodating portion 31. These mounting legs 31d are dispersedly arranged around the boss portion 31c, and are projected in the same direction as the protruding direction of the boss portion 31c (front direction in the drawing). A female screw portion F is formed on the mounting leg 31d, whereby the wiper motor 20 is fixed to the mounting bracket mounted on the vehicle 10 side by three fixing bolts (not shown). To.

A plurality of reinforcing ribs RB are radially provided around the boss portion 31c, thereby reinforcing the bottom wall 31a. Therefore, the wall thickness of the bottom wall 31a can be made thinner, which also makes the wiper motor 20 smaller and lighter.

The first opening OP of the speed reduction mechanism accommodating portion 31 is closed by the cover member 40 shown in FIGS. 5 and 6. Here, the cover member 40 is fixed to the speed reduction mechanism accommodating portion 31 with three fixing screws SC2 (see FIG. 3). An elastic seal (not shown) such as a rubber packing is provided between the speed reduction mechanism accommodating portion 31 and the cover member 40 to prevent rainwater or the like from entering the inside of the deceleration mechanism accommodating portion 31. Will be done. The cover member 40 is formed in a bottomed shape by injection molding or the like of a molten plastic material, and its outer shape is substantially the same as the outer shape of the speed reduction mechanism accommodating portion 31 as shown in FIGS. 2 and 3. It has a shape.

As shown in FIGS. 5 and 6, the cover member 40 includes a cover body 41 that forms the bottom of the cover member 40. Further, around the cover main body 41, a seal mounting portion 42 on which an elastic seal is mounted is integrally provided. Further, the seal mounting portion 42 of the cover member 40 is integrally formed with a connector connecting portion 43 to which the external connector CN (see FIG. 2) on the vehicle 10 side is connected.

Here, the connector connection portion 43 is formed in a substantially box shape, and one end side of each of the connector-side conductive members UBAT, GND, and LIN is exposed inside the connector connection portion 43 (not shown). Further, the conductive members UBAT, GND, and LIN on the connector side are bent by press molding or the like of a copper plate or the like having excellent conductivity, and are integrated with the cover main body 41 by insert molding. The other ends of the connector-side conductive members UBAT, GND, and LIN are each exposed in the vicinity of the connector connection portion 43 inside the cover body 41, and are electrically exposed to the substrate 80 (see FIGS. 5 and 7). It is connected.

A drive current (battery power supply) is supplied to the connector-side conductive member UBAT from the external connector CN, and the connector-side conductive member GND is body-grounded (grounded) via the external connector CN to the connector-side conductive member LIN. Is input with an operation signal such as a wiper switch (not shown) from the external connector CN.

As shown in FIG. 6, inside the cover main body 41, in addition to the connector-side conductive members UBAT, GND, and LIN, three motor-side conductive members MC1, MC2, and MC3 are integrated by insert molding, respectively. .. Similar to the connector-side conductive members UBAT, GND, and LIN, these motor-side conductive members MC1, MC2, and MC3 are also bent by press-molding a copper plate or the like having excellent conductivity.

Then, one end side of the motor-side conductive members MC1, MC2, MC3 is electrically connected to the female terminals TM1, TM2, TM3 (see FIG. 4) of the motor-side terminal portion 62a in a state where the wiper motor 20 is assembled. To. That is, one end side of the motor-side conductive members MC1, MC2, and MC3 is a male terminal. Further, the motor-side conductive member MC1 corresponds to the U-phase coil, the motor-side conductive member MC2 corresponds to the V-phase coil, and the motor-side conductive member MC3 corresponds to the W-phase coil.

As shown in FIG. 6, the other ends of the motor-side conductive members MC1, MC2, and MC3 are respectively arranged at substantially central portions inside the cover main body 41. The other ends of the motor-side conductive members MC1, MC2, and MC3 are electrically connected to the substrate 80 (see FIGS. 5 and 7). As described above, the motor-side conductive members MC1, MC2, and MC3 are provided between the substrate 80 and the motor 60, respectively.

Here, the other end side of the connector side conductive members UBAT, GND, and LIN, and the other end side of the motor side conductive members MC1, MC2, and MC3 are electrically connected to the substrate 80 by soldering or the like, respectively. In FIG. 6, in order to make it easy to understand the arrangement relationship of the respective conductive members UBAT, GND, LIN, MC1, MC2, MC3 (six in total), these conductive members UBAT, GND, LIN, MC1, MC2, The MC3 is shaded.

As shown in FIGS. 5 and 7, a substrate 80 for controlling the wiper motor 20 is mounted inside the cover main body 41. Specifically, the substrate 80 is fixed to the inside of the cover main body 41 by a plurality of fixing screws (not shown). A plurality of electronic component EPs are mounted on the front surface 80a (see FIG. 5) and the back surface 80b (see FIG. 7) of the substrate 80, respectively.

Further, as shown in FIG. 7, a total of three Hall elements 81a, 81b, and 81c are mounted on the back surface 80b of the substrate 80. These Hall elements 81a, 81b, and 81c are provided on the outer side in the radial direction of the first sensor magnet MG1 in a state where the wiper motor 20 is assembled (see FIGS. 9 and 10).

More specifically, as shown in FIG. 9, the Hall elements 81a, 81b, 81c are lines orthogonal to the axis (rotation center C) of the first sensor magnet MG1 on the radial outer side of the first sensor magnet MG1. They are provided side by side on the minute LN1 at predetermined intervals S3. As a result, the Hall elements 81a, 81b, and 81c detect the rotation speed, rotation direction, and the like of the rotation shaft 64 (first sensor magnet MG1).

The Hall element 81a is used to drive the U-phase coil, the Hall element 81b is used to drive the V-phase coil, and the Hall element 81c is used to drive the W-phase coil. Used. That is, the motor 60 (see FIG. 2) provided with the three-phase (U-phase, V-phase, W-phase) coil has three Hall elements 81a corresponding to the three-phase coils of the U-phase, V-phase, and W-phase. , 81b, 81c are provided.

Further, one MR sensor 82 is mounted on the back surface 80b of the substrate 80. The MR sensor 82 faces the second sensor magnet MG2 (see FIG. 4) in a state where the wiper motor 20 is assembled. As a result, the MR sensor 82 detects the rotation direction, rotation position, and the like of the output shaft 73.

Further, as shown in FIG. 7, one CPU 83 and two FET elements 84 (six in total) for each of the U phase, the V phase, and the W phase are mounted on the back surface 80b of the substrate 80. .. Then, sensor signals from the Hall elements 81a, 81b, 81c and the MR sensor 82 are input to the CPU 83, respectively. The CPU 83 switches the FET elements 84 at predetermined timings in response to the input of these sensor signals, whereby the motor 60 (see FIG. 2) is rotationally driven (controlled) at a predetermined rotation speed in a predetermined direction. Will be done.

The first, second, and third through holes TH1, TH2, and TH3 are provided side by side in the vicinity of the corners of the substrate 80. The other end side (see FIG. 6) of the connector-side conductive member UBAT is electrically connected to the first through-hole TH1, and the other end side (FIG. 6) of the connector-side conductive member GND is electrically connected to the second through-hole TH2. 6) is electrically connected, and the other end side (see FIG. 6) of the connector-side conductive member LIN is electrically connected to the third through hole TH3.

Fourth, fifth, and sixth through holes TH4, TH5, and TH6 are provided side by side in a substantially central portion of the substrate 80. The other end side (see FIG. 6) of the motor-side conductive member MC1 is electrically connected to the fourth through hole TH4, and the other end side (FIG. 6) of the motor-side conductive member MC2 is electrically connected to the fifth through-hole TH5. 6) is electrically connected, and the other end side (see FIG. 6) of the motor-side conductive member MC3 is electrically connected to the sixth through hole TH6.

Further, the substrate 80 is mounted with a substrate cover 90 as shown in FIGS. 5 and 8. That is, the substrate 80 is arranged between the cover main body 41 and the substrate cover 90 inside the reduction mechanism accommodating portion 31 (see FIG. 4).

The substrate cover 90 is formed in a thin plate shape by injection molding a resin material such as plastic, and has a front surface 90a (see FIG. 5) on the substrate 80 side and a back surface 90b on the reduction mechanism 70 (see FIG. 4) side. (See FIG. 8). By providing the substrate cover 90 between the substrate 80 and the deceleration mechanism 70 in this way, the grease (not shown) applied to the deceleration mechanism 70 (worm 71 and worm wheel 72) is scattered on the substrate 80. Is prevented from adhering.

A through hole 91 that penetrates the front surface 90a side and the back surface 90b side is provided in a substantially central portion of the substrate cover 90. The through hole 91 is provided at a portion facing the second sensor magnet MG2 (see FIG. 4) and the MR sensor 82 (see FIG. 7), whereby an obstacle between the second sensor magnet MG2 and the MR sensor 82 is provided. Is eliminated to prevent the detection accuracy of the MR sensor 82 from being lowered. Here, since the grease is applied to the meshing portion between the worm 71 and the worm wheel 72, the grease does not reach the portion of the through hole 91.

As shown in FIG. 5, a total of three support claws 92 are provided on the surface 90a side of the substrate cover 90, and these support claws 92 are hooked on the substrate 80 fixed to the cover main body 41. It has become. As a result, the substrate cover 90 is fixed to the cover member 40 via the substrate 80 without rattling.

Further, as shown in FIG. 8, a covering wall 93 that covers a part of the periphery of the worm 71 (see FIG. 4) is provided on the back surface 90b side of the substrate cover 90. The worm 71 is rotatably housed inside the covering wall 93, and the covering wall 93 prevents the grease applied to the worm 71 from scattering to the surroundings.

Here, a plurality of holding walls 93a are provided inside the covering wall 93, and these holding walls 93a extend in a direction orthogonal to the axial direction of the worm 71 (extending direction of the rotation center C) and are worms. They are arranged side by side at substantially equal intervals in the axial direction of 71. The holding wall 93a prevents the grease applied to the worm 71 from being biased to one side in the axial direction or the other side in the axial direction as the worm 71 rotates. As a result, the deceleration mechanism 70 (see FIG. 4) can operate smoothly for a long period of time.

Further, as shown in FIGS. 5 and 8, a total of three magnetic transmission members 101, 102, are formed between the front surface 90a and the back surface 90b of the substrate cover 90 so as to cross in the thickness direction of the substrate cover 90. 103 is provided. These magnetic transmission members 101, 102, and 103 are in a non-contact state with each other, and a part of them is embedded in the substrate cover 90 when the substrate cover 90 is injection-molded. That is, the magnetic transmission members 101, 102, and 103 are integrated with the substrate cover 90 by insert molding.

The magnetic transmission members 101, 102, and 103 are made of a soft magnetic material (ferritic stainless steel or the like) having a small force for holding a magnetic force and excellent magnetic permeability, and have a shape as shown in FIG. The magnetic transmission members 101, 102, and 103 are formed into a predetermined shape by punching and bending a plate-shaped soft magnetic material. Then, the magnetism generated by the first sensor magnet MG1 (see FIGS. 9 and 10) is transmitted to the magnetic transmission members 101, 102, 103, and the magnetism is transmitted to the three Hall elements 81a, 81b, 81c (FIGS. 9 and 10). It has a function to transmit to (see).

The magnetic transmission member 101 is provided corresponding to the Hall element 81a (U-phase coil), and the magnetic transmission member 102 is provided corresponding to the Hall element 81b (V-phase coil). Is provided corresponding to the Hall element 81c (W phase coil).

More specifically, the magnetic transmission member 101 includes a first magnetic transmission unit 101a arranged on the back surface 90b side of the substrate cover 90, and a second magnetic transmission unit 101b arranged on the front surface 90a side of the substrate cover 90. It includes a third magnetic transmission unit 101c that connects the first magnetic transmission unit 101a and the second magnetic transmission unit 101b.

Further, the magnetic transmission member 102 is exposed on both the first magnetic transmission portion 102a arranged on the back surface 90b side of the substrate cover 90 and both the front surface 90a side and the back surface 90b side of the substrate cover 90 (see FIGS. 5 and 8). The second magnetic transmission unit 102b is provided, and a third magnetic transmission unit 102c that connects the first magnetic transmission unit 102a and the second magnetic transmission unit 102b is provided.

Further, the magnetic transmission member 103 includes a first magnetic transmission unit 103a arranged on the back surface 90b side of the substrate cover 90, a second magnetic transmission unit 103b arranged on the front surface 90a side of the substrate cover 90, and a first magnetic transmission. A third magnetic transmission unit 103c that connects the unit 103a and the second magnetic transmission unit 103b is provided. Here, as shown in FIG. 9, the magnetic transmission member 103 has a shape to be mirrored with respect to the magnetic transmission member 101 on the left and right sides in the drawing with the portion of the rotation center C of the rotation shaft 64 as a boundary. There is.

That is, as shown in FIG. 9, the volumes of the magnetic transmission member 101 and the magnetic transmission member 103 arranged on both sides of the rotation center C in the drawing are set to the same volume VL1. On the other hand, the volume of the magnetic transmission member 102 arranged directly below the rotation center C in the drawing is set to a volume VL2 smaller than the volume VL1 of the magnetic transmission members 101 and 103 (VL2 <VL1).

As described above, of the magnetic transmission members 101, 102, 103, the volume of the magnetic transmission member provided on the side where the separation distance between the first sensor magnet MG1 and the Hall element is long, that is, the separation distance is L1. The volume VL1 of the magnetic transmission members 101 and 103 corresponding to the Hall elements 81a and 81c is the volume of the magnetic transmission member provided on the side where the separation distance between the first sensor magnet MG1 and the Hall element is shorter, that is, the separation distance. Is larger than the volume VL2 of the magnetic transmission member 102 corresponding to the Hall element 81b at L2.

Here, in FIG. 9, in order to make it easy to understand the arrangement relationship of the magnetic transmission members 101, 102, 103, the magnetic transmission members 101, 102, 103 are shaded and the magnetic transmission members 101, 102, 103, Only the substrate 80 on which the rotating shaft 64 to which the first sensor magnet MG1 is fixed and the Hall elements 81a, 81b, 81c are mounted is shown.

As shown in FIGS. 8 and 9, the first magnetic transmission portions 101a, 102a, 103a forming the magnetic transmission members 101, 102, 103 are end faces (one in the axial direction) of the first sensor magnet MG1 on one end side in the axial direction. (End face) Arranged along EM1 and facing each other, each is formed in a substantially arc shape. The first magnetic transmission units 101a, 102a, 103a each include a facing surface SF1 (see FIG. 8) facing the end surface EM1 of the first sensor magnet MG1.

In this way, by making the first magnetic transmission units 101a, 102a, 103a face the end face EM1 of the first sensor magnet MG1, it is necessary to arrange the first magnetic transmission unit on the radial outer side of the first sensor magnet MG1. As a result, the wiper motor 20 (see FIG. 2) can be miniaturized.

Here, as shown in FIG. 10, the clearance dimensions between the end surface EM1 of the first sensor magnet MG1 and the facing surfaces SF1 of the first magnetic transmission portions 101a, 102a, 103a are the magnetic transmission members 101, 102, The clearance dimension S1 is set to be smaller than the wall thickness dimension of 103. As a result, the magnetism of the first sensor magnet MG1 is surely transmitted to the first magnetic transmission units 101a, 102a, 103a (improvement of sensing accuracy).

Then, as shown in FIG. 9, the first magnetic transmission units 101a, 102a, 103a are the sides of the end face EM1 of the first sensor magnet MG1 provided with the Hall elements 81a, 81b, 81c (lower in the figure). It is arranged in the range of 180 degrees on the side). Specifically, the Hall element 81a, rather than the line segment LN2 that is orthogonal to the rotation center C, passes through the rotation center C, and is parallel to the line segment LN1 connecting the Hall elements 81a, 81b, and 81c. The first magnetic transmission units 101a, 102a, 103a are arranged on the 81b, 81c side (the substrate 80 side).

As a result, it is possible to avoid increasing the size of the magnetic transmission members 101, 102, 103, and from the back surface 80b side of the substrate 80, that is, the side on which the Hall elements 81a, 81b, 81c are mounted (upper side in FIG. 9), the first sensor The rotating shaft 64 to which the magnet MG1 is fixed can be easily assembled at a specified position (improvement of assembling property).

The first magnetic transmission units 101a, 102a, and 103a are each set to the same size (volume), and are arranged in a range of approximately 60 degrees with respect to the rotation direction of the first sensor magnet MG1. The first magnetic transmission units 101a, 102a, and 103a are in a non-contact state with each other through a predetermined gap S2. Here, the predetermined gap S2 is set to a gap such that the respective magnetisms passing through the first magnetic transmission units 101a, 102a, 103a do not adversely affect (not transmit) the other magnetic transmission units (S2≈ 3 x S1). Therefore, the decrease in sensing accuracy is suppressed (improvement in sensing accuracy).

As shown in FIGS. 8 and 9, the second magnetic transmission portions 101b, 102b, 103b forming the magnetic transmission members 101, 102, 103 are set to the same size (volume), respectively, and have a substantially rectangular flat plate shape. It has become. The second magnetic transmission unit 101b, 102b, 103b includes facing surfaces SF2 facing the detection surfaces EM2 (see FIG. 7) of the Hall elements 81a, 81b, 81c, respectively.

Then, as shown in FIG. 9, the gap dimensions between the second magnetic transmission units 101b, 102b, 103b and the Hall elements 81a, 81b, 81c are the first sensor magnet MG1 and the first magnetic transmission unit 101a. , 102a, 103a are set to have substantially the same gap dimension S1 as the gap dimension S1. As a result, the respective magnetism transmitted to the second magnetic transmission units 101b, 102b, 103b can be accurately detected by the respective Hall elements 81a, 81b, 81c (improvement of sensing accuracy).

Further, as shown in FIGS. 8 and 9, the third magnetic transmission units 101c, 102c, 103c have the first magnetic transmission units 101a, 102a, 103a and the second magnetic transmission units 101b, 102b, 103b, respectively. It is connected. That is, the third magnetic transmission units 101c, 102c, 103c have a function of transmitting the magnetism transmitted to the first magnetic transmission units 101a, 102a, 103a to the second magnetic transmission units 101b, 102b, 103b. ..

Then, the third magnetic transmission units 101c and 103c of the magnetic transmission member 101 and the magnetic transmission member 103 are set to the same volume, respectively, and the volume of the third magnetic transmission unit 102c of the magnetic transmission member 102 is the volume of the third magnetic transmission unit 101c. , 103c is smaller than the volume. By making the volumes of the third magnetic transmission units 101c and 103c different from those of the third magnetic transmission unit 102c in this way, the total volume VL2 of the magnetic transmission member 102 can be changed to the total volume of the magnetic transmission members 101 and 103. It is smaller than VL1.

Here, as shown in FIG. 9, the three Hall elements 81a, 81b, and 81c are provided side by side on the flat back surface 80b of the substrate 80 at predetermined intervals. Specifically, the three Hall elements 81a, 81b, and 81c are arranged side by side through an interval S3 larger than the radial dimension D / 2 of the first sensor magnet MG1 (S3> D / 2). That is, the separation distance (2 × S3) between the pair of Hall elements 81a, 81c arranged on both sides of the three Hall elements 81a, 81b, 81c arranged side by side is the outer diameter dimension D of the first sensor magnet MG1. (2 x S3> D).

In this way, by setting the distance S3 of the three Hall elements 81a, 81b, 81c to be relatively large, the respective Hall elements 81a, 81b, 81c are prevented from picking up magnetism from other magnetic transmission members. .. Therefore, this also suppresses the decrease in sensing accuracy (improvement in sensing accuracy).

Furthermore, by setting the distance S3 between the Hall elements 81a, 81b, and 81c to be relatively large, the distance S3 between the first sensor magnet MG1 and the Hall element 81b (corresponding to the V-phase coil) is higher than the distance L2. The separation distance L1 between the 1-sensor magnet MG1 and the Hall elements 81a and 81c (corresponding to the U-phase coil and the W-phase coil) is lengthened to increase the difference (L1-L2). Specifically, the separation distance L1 is approximately three times the separation distance L2 (L1≈3 × L2).

As described above, in the present embodiment, the difference (L1-L2) between the separation distance L1 and the separation distance L2 is increased by setting the distance S3 between the adjacent Hall elements 81a, 81b, 81c to be large. .. Along with this, the total volume VL1 of the magnetic transmission members 101 and 103 (see FIG. 8) is also larger than the total volume VL2 of the magnetic transmission members 102 (see FIG. 8). It has been found that the difference in size between the volume VL1 and the volume VL2 has an advantageous effect in improving the sensing accuracy of the Hall elements 81a, 81b, and 81c, respectively.

That is, as shown in the graph of FIG. 11A, the farther (larger) the separation distance L between the sensor magnet and the Hall element is, the more difficult it is for magnetism to reach the Hall element. In other words, the farther the separation distance L is, the weaker the magnetic flux density B passing through the Hall element. A decrease in the magnetic flux density B passing through the Hall element causes a decrease in sensing accuracy.

On the other hand, as shown in the graph of FIG. 11B, the larger the volume V of the magnetic transmission member arranged between the sensor magnet and the Hall element, the larger the separation distance L between the sensor magnet and the Hall element. Even if it is far away, the magnetism transmitted through the magnetic transmission member can easily reach the Hall element. That is, in the graph of FIG. 11B, as the separation distance L between the sensor magnet and the Hall element increases, the volume V of the magnetic transmission member arranged between the sensor magnet and the Hall element increases. , It is shown that the decrease in sensing accuracy can be suppressed.

Based on the above reasons, in the present embodiment, the distance S3 between adjacent Hall elements is set to a relatively large value (S3> D / 2). As a result, each Hall element can be made less susceptible to the influence of magnetism from other magnetic transmission members, and the volume VL1 of the magnetic transmission members 101 and 103 is made larger than the volume VL2 of the magnetic transmission member 102. Can be done (VL1> VL2). Therefore, it is possible to suppress variations in the magnetic sensing accuracy from the first sensor magnet MG1 in the Hall elements 81a, 81b, and 81c, and to drive the wiper motor 20 (see FIG. 2) with higher accuracy. Become.

As described in detail above, according to the wiper motor 20 according to the present embodiment, the Hall elements 81a, 81b, 81c are located on the radial outer side of the first sensor magnet MG1 along the axis (rotation center C) of the first sensor magnet MG1. ), The magnetic transmission members 101, 102, 103 are provided side by side at predetermined intervals S3, respectively, and the magnetic transmission members 101, 102, 103 are the first magnetic transmission portions 101a, 102a facing the end surface EM1 of the first sensor magnet MG1. , 103a, the second magnetic transmission units 101b, 102b, 103b facing the detection surface EM2 of the Hall elements 81a, 81b, 81c, the first magnetic transmission units 101a, 102a, 103a and the second magnetic transmission units 101b, 102b, The third magnetic transmission units 101c, 102c, and 103c for connecting the 103b are provided, respectively.

Therefore, the first magnetic transmission portions 101a, 102a, 103a of the magnetic transmission members 101, 102, 103 are opposed to the end face EM1 of the first sensor magnet MG1, and the first sensor magnet MG1 and the Hall elements 81a, 81b, 81c are combined with each other. Can be placed closer than before. Therefore, the shapes and arrangement structures of the magnetic transmission members 101, 102, and 103 can be simplified, and the entire wiper motor 20 can be made smaller and lighter.

Further, according to the wiper motor 20 according to the present embodiment, the first magnetic transmission units 101a, 102a, 103a are on the side of the end face EM1 of the first sensor magnet MG1 where the Hall elements 81a, 81b, 81c are provided. It is arranged in the range of 180 degrees.

As a result, it is possible to avoid increasing the size of the magnetic transmission members 101, 102, 103, and the first sensor magnet MG1 is fixed from the back surface 80b side of the substrate 80, that is, the side on which the Hall elements 81a, 81b, 81c are mounted. The rotating shaft 64 can be easily assembled at a specified position (improvement of assembling property).

Further, according to the wiper motor 20 according to the present embodiment, the volume of the magnetic transmission member provided on the magnetic transmission member 101, 102, 103 having a longer separation distance between the first sensor magnet MG1 and the Hall element. That is, the volume VL1 of the magnetic transmission members 101 and 103 corresponding to the Hall elements 81a and 81c having a separation distance of L1 is provided on the side where the separation distance between the first sensor magnet MG1 and the Hall element is short. The volume of the magnetic transmission member, that is, the separation distance is L2, which is larger than the volume VL2 of the magnetic transmission member 102 corresponding to the Hall element 81b.

As a result, it is possible to prevent variations in the magnetic sensing accuracy from the first sensor magnet MG1 in the Hall elements 81a, 81b, and 81c, and to drive the wiper motor 20 with higher accuracy.

Further, according to the wiper motor 20 according to the present embodiment, the three Hall elements 81a, 81b, 81c are mounted side by side on the substrate 80, and among the three Hall elements 81a, 81b, 81c arranged side by side. The separation distance (2 × S3) between the pair of Hall elements 81a and 81c arranged on both sides is larger than the outer diameter dimension D of the first sensor magnet MG1.

As a result, the Hall elements 81a, 81b, and 81c can be prevented from picking up magnetism from other magnetic transmission members, and thus a decrease in sensing accuracy can be suppressed.

Further, according to the wiper motor 20 according to the present embodiment, the first sensor magnet MG1 is provided with four poles of magnetic poles having different polarities alternately in the circumferential direction, and the magnetic transmission members 101, 102, 103 are provided. Three are provided corresponding to the U-phase, V-phase, and W-phase coils wound around the stator 61.

As a result, it is possible to detect four magnetic changes at different timings for each of the Hall elements 81a, 81b, and 81c while the rotation shaft 64 makes one rotation. Therefore, the CPU 83 mounted on the substrate 80 can control the rotational state of the rotating shaft 64 with high accuracy.

Further, according to the wiper motor 20 according to the present embodiment, the Hall elements 81a, 81b, 81c are used to detect the rotational state of the rotating shaft 64.

As a result, it is possible to reduce the number of failures in addition to being relatively inexpensive, compact and lightweight, and it is possible to further reduce the size and weight of the wiper motor 20 and improve its reliability.

Further, according to the wiper motor 20 according to the present embodiment, the output shaft 73 rotated by the rotating shaft 64 is provided, and the output shaft 73 swings the wiper arm 13 and the wiper blade 15.

As a result, the output shaft 73 can be rotated in the forward and reverse directions with high accuracy, and the wiper arm 13 and the wiper blade 15 can be reliably inverted at the specified inversion positions (upward inversion position and downward inversion position). It is possible to cleanly wipe the wiped range 16.

It goes without saying that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist thereof. For example, in the above embodiment, the sensor for detecting the rotation direction, rotation position, etc. of the output shaft 73 is the MR sensor 82, but the present invention is not limited to this, and a plurality of Hall elements are included in one component. It is also possible to use a rotation angle sensor configured by.

Further, in the above embodiment, the case where the wiper motor 20 is used as the drive source of the wiper device for wiping the front windshield 11 of the vehicle 10 is shown, but the present invention is not limited to this, and the rear wiper of a vehicle such as an automobile is not limited to this. It can also be used as a drive source for a device or a wiper device such as a railroad vehicle or an aircraft.

In addition, the material, shape, dimensions, number, installation location, etc. of each component in the above embodiment are arbitrary as long as the present invention can be achieved, and are not limited to the above embodiment.

10 Vehicle 11 Front windshield 12 Wiper device 13 Wiper arm (wiper member)
14 Link mechanism 15 Wiper blade (wiper member)
16 Wiping range 20 Wiper motor (brushless motor)
30 Housing 31 Deceleration mechanism accommodating part 31a Bottom wall 31b Side wall 31c Boss part 31d Mounting leg 31e First through hole 31f Second through hole 32 Motor fixing part 32a Flange part 40 Cover member 41 Cover body 42 Seal mounting part 43 Connector connection part 50 Motor cover 51 Bottom 52 Cover flange 60 Motor 61 Stator 62 Terminal holder 62a Motor side terminal 63 Rotor 64 Rotating shaft 70 Deceleration mechanism 71 Warm 72 Warm wheel 72a Gear tooth 73 Output shaft 80 Board 80a Front surface 80b Back surface 81a, 81b, 81c Element (rotation sensor)
82 MR sensor 83 CPU
84 FET element 90 Substrate cover 90a Front surface 90b Back surface 91 Through hole 92 Support claw 93 Covering wall 93a Holding wall 101, 102, 103 Magnetic transmission member 101a, 102a, 103a First magnetic transmission unit 101b, 102b, 103b Second magnetic transmission unit 101c, 102c, 103c Third magnetic transmission part B Magnetic flux density BE Bearing member C Rotation center CN External connector EM1 end face (one end face in the axial direction)
EM2 Detection surface EP Electronic component F Female thread part GND Connector side conductive member L, L1, L2 Separation distance LIN Connector side conductive member LN1, LN2 Line segment MC1, MC2, MC3 Motor side conductive member MG1 First sensor magnet (magnet)
MG2 2nd sensor magnet OP 1st opening RB Reinforcing rib SC1 Fastening screw SC2 Fixing screw SF1, SF2 Facing surface TH1 1st through hole TH2 2nd through hole TH3 3rd through hole TH4 4th through hole TH5 5th through hole TH6 6th Through Hole TM1, TM2, TM3 Female Terminal UBAT Connector Side Conductive Member V, VL1, VL2 Volume WS Fixed Washer

Claims (7)

With the stator
A rotor rotatably provided with respect to the stator and
A rotating shaft fixed to the center of rotation of the rotor,
It is a brushless motor equipped with
An annular magnet fixed to the rotating shaft and having a plurality of magnetic poles arranged alternately in the rotating direction of the rotating shaft.
The magnetism generated by the magnet is transmitted, and a plurality of magnetic transmission members provided in a state of non-contact with each other
A plurality of rotation sensors for detecting the magnetism transmitted to the plurality of magnetic transmission members, and
Have,
The plurality of rotation sensors
On the radial outer side of the magnet, they are provided side by side at predetermined intervals on a line segment orthogonal to the axis of the magnet.
The plurality of the magnetic transmission members are
A first magnetic transmission unit facing the axial end surface of the magnet, and
A second magnetic transmission unit facing the detection surface of the rotation sensor,
A third magnetic transmission unit that connects the first magnetic transmission unit and the second magnetic transmission unit,
A brushless motor that is characterized by having each. The brushless motor according to claim 1, wherein the first magnetic transmission unit is arranged in a range of 180 degrees on the side of the one end surface of the magnet in the axial direction where the rotation sensor is provided. .. Of the plurality of magnetic transmission members, the volume of the magnetic transmission member provided on the side where the distance between the magnet and the rotation sensor is long is the one in which the distance between the magnet and the rotation sensor is short. The brushless motor according to claim 1 or 2, wherein the volume is larger than the volume of the magnetic transmission member provided in the above. The three rotation sensors are mounted side by side on the board.
Any of claims 1 to 3, wherein the distance between the pair of rotation sensors arranged on both sides of the three arranged rotation sensors is larger than the outer diameter of the magnet. The brushless motor according to item 1. The magnet is provided with four poles of magnetic poles having different polarities alternately in the circumferential direction, and the magnetic transmission member corresponds to a U-phase, V-phase, and W-phase coil wound around the stator. The brushless motor according to any one of claims 1 to 4, characterized in that three are provided. The brushless motor according to any one of claims 1 to 5, wherein the rotation sensor is a Hall element. The brushless motor according to any one of claims 1 to 6.
Further, an output shaft rotated by the rotation shaft is provided.
The output shaft is a brushless motor characterized by swinging a wiper member.

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