motor

Abstract

For example, the present application provides a motor that prevents metal powder from adhering to a sensor. For example, a motor (1) includes a rotating shaft (S), a bracket (2) formed of a non-magnetic material, a bearing (32) that supports the rotating shaft (S) so as to be rotatable with respect to the bracket (2), a commutator (34), a magnet (7) fixed to the rotating shaft (S), a sensor (6) disposed on one face (2a) of the bracket (2) in the direction of the rotating shaft, and a brush (35) disposed on the other face (2b) of the bracket (2) in the direction of the rotating shaft, and the sensor (6) detects the magnetic flux of the magnet (7).

Description

Technical Field

[0001] This invention relates to a motor. Background Technology

[0002] As a brushed DC (Direct Current) motor, motors equipped with sensors that detect the rotation of the motor are known. For example, Patent Document 1 discloses a motor in which a pulse receiver is inserted into a pocket formed in a substrate.

[0003] Existing technical documents Patent documents Patent Document 1: Japanese Patent Publication No. 2003-501997 Summary of the Invention

[0004] The problem that the invention aims to solve In brushed DC motors, if metal powder generated by friction between the brushes and the rectifier adheres to the sensor, a short circuit between terminals may occur, for example. One example of the technical problem addressed by this invention is to provide a motor that prevents metal powder from adhering to the sensor.

[0005] Solution for solving the problem As an example of the present invention, a motor includes: a rotating shaft; a bracket formed of a non-magnetic body; a bearing supporting the rotating shaft so as to be rotatable relative to the bracket; a rectifier; a magnet fixed to the rotating shaft; a sensor disposed on one side of the bracket in the direction of the rotating shaft; and a brush disposed on the other side of the bracket in the direction of the rotating shaft, the sensor detecting the magnetic flux of the magnet. Attached Figure Description

[0006] Figure 1 This is a perspective view of a motor as an example embodiment of the present invention; Figure 2 This is a perspective view of the bracket provided by a motor as an example embodiment of the present invention; Figure 3 This is another perspective view of the bracket provided by the motor as an example embodiment of the present invention; Figure 4 This is a perspective view showing an enlarged view of the pocket of the bracket provided by the motor, which is an example embodiment of the present invention. Figure 5 This is a perspective view of a sensor included in a motor as an example embodiment of the present invention. Figure 6 This is a perspective view showing an example of a scheme in which a sensor in a motor is housed in a pocket of a bracket, as an embodiment of the present invention. Figure 7This is a perspective view showing an example of a scheme in which the wiring of a sensor in a motor is connected to a substrate, as an example embodiment of the present invention. Figure 8 This is a perspective view showing an example of a scheme in which brushes are arranged in a bracket of a motor, which is an example embodiment of the present invention. Figure 9 This is a cross-sectional perspective view showing an example of the configuration of sensors and brushes in a motor, which is an example embodiment of the present invention. Figure 10 This is a cross-sectional perspective view showing an example of the configuration of the rectifier and brushes in a motor, which is an embodiment of the present invention. Figure 11 This is a perspective view showing a cross-sectional view of a motor, as an example embodiment of the present invention, obtained by cutting along a plane of rotation. Detailed Implementation

[0007] In the description of embodiments of the present invention, for ease of explanation, the direction along the rotation axis S is defined as the rotation axis direction. In the rotation axis direction, the direction from the motor body 3 toward the bracket 2 (arrow a direction) is defined as one side, and the opposite direction (arrow b direction) is defined as the other side. Furthermore, the direction of arrow cd, orthogonal to the rotation axis S, is referred to as radial, the direction of arrow c, which is away from the rotation axis S, is referred to as the outer side or one side radially, and the direction of arrow d, which is close to the rotation axis S, is referred to as the inner side or the other side radially. In a certain component or part, sometimes the outer surface radially (arrow c direction) is referred to as the outer peripheral surface, and the inner surface radially (arrow d direction) is referred to as the inner peripheral surface. Moreover, sometimes the direction of rotation about the rotation axis S is referred to as the circumferential direction.

[0008] The following refers to the attached diagram ( Figures 1 to 11 The following describes an embodiment that is an example of the present invention. Figure 1 This is a perspective view showing the overall configuration of the motor 1 in this embodiment. Figure 2 This is a perspective view of the bracket 2 provided by the motor 1, showing one side 2a of the bracket 2 in a way that is easily visually recognizable. Figure 3 This is another perspective view of bracket 2, showing another side 2b of bracket 2 in a way that is easily visually recognizable. Figure 4 This is a perspective view showing the other side of the pocket 26 of the bracket 2 along the direction of its rotation axis in a way that is easily visually recognizable. It should be noted that... Figure 4 In the image, the sensor 6, hidden inside the pocket 26, is represented by a dashed line. Figure 5 This is a 3D view of sensor 6, which is part of motor 1. Figure 6 This is a perspective view showing an example of a scheme in which the sensor 6 is housed in the pocket 26 of the bracket 2. Figure 7This is a perspective view showing an example of a scheme in which the wiring 62 of the sensor 6 is connected to the substrate 5. Figure 8 This is a perspective view showing an example of a scheme in which brush 35 is configured in bracket 2. Figure 9 This is a cross-sectional perspective view showing an example of the configuration of sensor 6 and brush 35. Figure 10 This is a cross-sectional perspective view showing an example of the configuration of rectifier 34 and brush 35. Figure 11 It is a sectional perspective view of the surface obtained by cutting along the center line of the rotation axis S in motor 1.

[0009] like Figure 1 As shown, motor 1 includes a rotating shaft S, a bracket 2, a motor body 3, a cover 4 (indicated by a dashed line), a substrate 5, and a sensor 6. Motor body 3 has a cylindrical housing 31. The bracket 2 is disposed on one side of motor body 3 in the direction of the rotating shaft (arrow a). The bracket 2 covers one side of housing 31 of motor body 3 in the direction of the rotating shaft (arrow a).

[0010] The bracket 2 has: a portion of the cylindrical housing 31 covering the motor body 3 (hereinafter referred to as cover 21); a portion protruding from the cover 21 to the radially outward side (arrow c direction) (hereinafter referred to as plate 22); and a housing protruding from the plate 22 to the other side (arrow b direction) in the direction of the rotation axis (hereinafter referred to as connector housing 23).

[0011] The substrate 5 is, for example, a flat printed circuit board (PCB) on which circuits and electronic components (not shown) are disposed. However, the substrate 5 may also have any other arbitrary shape. The substrate 5 is disposed on one side of the plate-shaped portion 22 of the bracket 2 in the direction of rotation axis (arrow a direction). The cover 4 is disposed on one side of the plate-shaped portion 22 of the bracket 2 in the direction of rotation axis (arrow a direction), covering the substrate 5.

[0012] Sensor 6 is positioned near the rotation axis S of the plate-shaped portion 22 of bracket 2. Figure 2 (Angle 221 shown). Sensor 6 is electrically connected to substrate 5. Sensor 6 and substrate 5 are covered by cover 4 from one side (arrow a direction) in the direction of rotation axis.

[0013] The following is for reference Figure 2 , Figure 3 as well as Figure 4 The details of bracket 2 are described below. Bracket 2 is formed of a non-magnetic material. Bracket 2 has a surface 2a ( ) facing one side (in the direction of arrow a) in the direction of the rotation axis. Figure 2 ) and another face 2b (towards the other side in the direction of the rotation axis (arrow b direction) Figure 3Here, one surface 2a refers to the surface of the bracket 2 facing the direction of the rotation axis (in the direction of arrow a). Furthermore, another surface 2b refers to the surface of the bracket 2 facing the other side (in the direction of arrow b) in the direction of the rotation axis.

[0014] The cover 21 of the bracket 2 has: a generally disc-shaped portion extending radially (hereinafter referred to as disc portion 211); a cylindrical portion extending radially outward from the outer edge of the disc portion 211 toward one side in the direction of rotation axis (arrow a direction) (hereinafter referred to as first outer peripheral portion 212); a portion protruding radially inward from another side 2b of the bracket 2 toward the other side in the direction of rotation axis (arrow b direction) (hereinafter referred to as second outer peripheral portion 213) at a position closer to the inner side in the radial direction than the first outer peripheral portion 212; and a first retainer 24 that accommodates or supports the first bearing 32 described later.

[0015] The second outer peripheral portion 213 is radially disposed between the first outer peripheral portion 212 and the first retainer 24. For example... Figure 3 As shown, on the outer peripheral surface 213o of the second outer peripheral portion 213, a plurality of ribs 214 (ten in this embodiment) are formed in a radially outward (arrow c direction) manner. Each of the plurality of ribs 214 has a curved surface (approximately semi-cylindrical in shape) extending along the rotation axis direction. When assembling the motor 1, the curved surface makes line contact or surface contact with the inner peripheral surface 31i of the housing 31 of the motor body 3 (see also...). Figure 10 It should be noted that some or all of the multiple ribs 214 may also be in a shape that makes point contact or surface contact with the inner circumferential surface of the housing 31 of the motor body 3.

[0016] like Figure 2 As shown, the first retainer 24 has: a cylindrical portion 241 that protrudes to one side (arrow a) in the direction of rotation axis and surrounds the rotation axis S; and an annular portion 242 that extends radially inward (arrow d) from the end of the cylindrical portion 241 on one side in the direction of rotation axis. The first retainer 24 supports the first bearing 32 (described later) on the radially inward side (arrow d) of the cylindrical portion 241 and on the other side (arrow b) in the direction of rotation axis of the annular portion 242.

[0017] like Figure 3 As shown, the cover 21 of the bracket 2 has a wall 215 protruding to the other side (in the direction of arrow b) in the direction of the rotation axis. The wall 215 includes two parts 215m and 215n, which are opposite to each other across the rotation axis S and the rectifier 34 described later, and each has an arc-shaped cross-sectional shape centered on the rotation axis S. The wall 215 is radially disposed outside the rectifier 34 described later, opposite to the rectifier 34 (see also...). Figure 10The wall 215 is radially disposed inside the second outer peripheral portion 213.

[0018] like Figure 3 As shown, on the other side (in the direction of arrow b) of the rotation axis direction of the cover 21 of the bracket 2, two radially extending, generally cylindrical frames 216 and 217 are connected. Frames 216 and 217 are symmetrically arranged opposite each other with respect to the rectifier 34 described later, separated by the rotation axis S (see also [reference]). Figure 10 The inner radial sides (in the direction of arrow d) of frames 216 and 217 are respectively arc-shaped with the rotation axis S as the center, and are opposite to rectifier 34.

[0019] Frames 216 and 217 extend radially from near the second outer periphery 213 to near the wall 215. On the other side (arrow b direction) of the rotation axis direction of frames 216 and 217, slits 216s and 217s are formed respectively from the radially outer end toward the inner side (arrow d direction).

[0020] The second outer peripheral portion 213 is divided into two parts 213m and 213n by frames 216 and 217. Similarly, the wall 215 is divided into two parts 215m and 215n by frames 216 and 217, with the two parts 215m and 215n separated by a predetermined distance in the circumferential direction. Part 213m of the second outer peripheral portion 213 is located on the side of part 215m of the wall 215. Similarly, part 213n of the second outer peripheral portion 213 is located on the side of part 215n of the wall 215. Frame 216 accommodates or supports the first brush 351 (described later), and frame 217 accommodates or supports the second brush 352 (described later).

[0021] A plate-shaped portion 22 is connected to the cover portion 21 of the bracket 2. The plate-shaped portion 22 is a generally rectangular portion that extends parallel or substantially parallel to the disc portion 211 of the cover portion 21. Figure 2 As shown, in the plate-shaped portion 22, a corner (the portion extending radially along the first retainer 24) 221 is connected to the vicinity of the first retainer 24 in the cover portion 21. A plurality of holes 222 (five in this embodiment) are formed in the plate-shaped portion 22. Terminals (not shown) that are connected to the substrate 5 and extend into the interior of the connector housing 23 are inserted into each hole 222.

[0022] like Figure 2As shown, a pocket 26 for accommodating the sensor 6 is provided at corner 221 of the plate-shaped portion 22 of the bracket 2. The pocket 26 opens on one side of the bracket 2, face 2a. The pocket 26 has a first recess 261 and a second recess 262. Both the first recess 261 and the second recess 262 are recessed toward the other side (arrow b) in the direction of the rotation axis. The first recess 261 is formed in a shape corresponding to the body 61 of the sensor 6 described later (hexagonal prism in this embodiment). The second recess 262 is formed radially from the first recess 261 toward the connector housing 23 (arrow c). The cross-section of the second recess 262 along the rotation axis S (the surface that passes through the centerline of the rotation axis S and extends radially and in the direction of the rotation axis) and the cross-section along the surface perpendicular to the direction of the rotation axis are both approximately quadrilateral. The size (depth of the recess) of the second recess 262 in the direction of the rotation axis is smaller than the size (depth of the recess) of the first recess 261.

[0023] Three grooves 263, 264, and 265, extending radially and along the axis of rotation, are formed circumferentially across the first recess 261 and the second recess 262 in the pocket 26. Two of the three grooves 263 and 265 have the same or approximately the same dimensions. Groove 264, sandwiched between two grooves 263 and 265, extends to a position radially closer to the connector housing 23 (in the direction of arrow c) than grooves 263 and 265.

[0024] like Figure 4 As shown, the pocket 26 protrudes towards the other side (in the direction of arrow b) in the direction of the rotation axis of the bracket 2 or towards the inside of the motor body 3. The pocket 26 is connected to a portion 215n of the wall 215 of the bracket 2. The pocket 26 has an inner peripheral portion 266, a side portion 267, and a bottom portion 268 that are radially opposite to the magnet 7 described later. The inner peripheral portion 266 is the radially inner side (in the direction of arrow d) of the pocket 26. The inner peripheral portion 266 is located on the side of the magnet 7 described later relative to the wall 215 of the bracket 2. That is, the pocket 26 protrudes radially inward (in the direction of arrow d) beyond the portion 215n of the wall 215 of the bracket 2.

[0025] Bottom 268 is the end of the pocket 26 on the other side (in the direction of arrow b) in the direction of rotation axis. Side 267 extends from the edge of bottom 268 toward one side (in the direction of arrow a) in the direction of rotation axis and reaches the disk portion 211. When sensor 6 is received in pocket 26, sensor 6 is surrounded by the inner periphery 266, side 267, and bottom 268 of pocket 26. Figure 4 In the diagram, the sensor 6 housed in the pocket 26 is indicated by a dashed line. In this embodiment, on the other side of the rotation axis of the bracket 2 (in the direction of arrow b), the sensor 6 is completely covered by the pocket 26.

[0026] like Figure 2and Figure 3 As shown, the connector housing 23 is a generally square-cylindrical portion whose end on one side (in the direction of arrow a) in the direction of rotation axis is covered by the plate-like portion 22. The connector housing 23 is axially disposed on the other side of the plate-like portion 22 of the bracket 2 (in the direction of arrow b), and radially disposed on the opposite side of the first retainer 24. By inserting the connector (not shown) into the connector housing 23, the substrate 5 is electrically connected to an external device (not shown).

[0027] The following is for reference Figure 5 , Figure 6 as well as Figure 7 The details of sensor 6 are described below. Sensor 6 is a sensor capable of detecting magnetic flux, and may be, for example, any of a Hall element, a Hall IC (Integrated Circuit), or a magnetoresistive element. Sensor 6 detects the magnetic flux of the magnet 7, which will be described later. It should be noted that in this specification, "detecting magnetic flux" may also refer to detecting changes in magnetic flux. Figure 5 As shown, the sensor 6 includes a body 61 and wiring (terminals) 62. The body 61 of the sensor 6 is formed in the shape of a hexagonal prism or a substantially hexagonal prism. The body 61 of the sensor 6 has: two parallel hexagonal or substantially hexagonal base surfaces (first base surface 611 and second base surface 612); and six side surfaces perpendicular to the first base surface 611 and the second base surface 612 (when viewed from the first base surface 611 side, they are, clockwise, first surface 613, second surface 614, third surface 615, fourth surface 616, fifth surface 617, and sixth surface 618). However, the body 61 of the sensor 6 may also have other shapes.

[0028] The first surface 613 is the largest surface area, extending parallel or substantially parallel to the fourth surface 616, which is the second largest surface area. The second surface 614 and the sixth surface 618, adjacent to the first surface 613, are the smallest surfaces, having the same or substantially the same size and shape, and extending parallel or substantially parallel to each other. The third surface 615 connects the second surface 614 and the fourth surface 616, and the fifth surface 617 connects the fourth surface 616 and the sixth surface 618.

[0029] Wiring 62 includes a first wiring 621, a second wiring 622, and a third wiring 623. The first wiring 621, the second wiring 622, and the third wiring 623 are arranged in a direction from the second surface 614 toward the sixth surface 618. Each of the first wiring 621, the second wiring 622, and the third wiring 623 extends perpendicularly from the second bottom surface 612 of the sensor 6 body 61, then bends and extends in the direction facing the first surface 613, and further bends and extends in the direction from the second bottom surface 612 toward the first bottom surface 611. The first wiring 621 and the third wiring 623 have the same shape and size. The second wiring 622, sandwiched between the first wiring 621 and the third wiring 623, extends longer in the direction facing the first surface 613 than the other two wirings in that direction.

[0030] Sensor 6 is inserted into the pocket 26 of bracket 2 in a direction from one side to the other (arrow b direction) along the rotation axis. In this way, sensor 6 is positioned on one surface 2a of bracket 2. Figure 6 As shown, when the sensor 6 is accommodated in the pocket 26 of the bracket 2, the body 61 of the sensor 6 is accommodated in the first recess 261 of the pocket 26, and the first wiring 621, the second wiring 622, and the third wiring 623 are accommodated in the slots 263, 264, and 265, respectively. That is, the first recess 261 of the pocket 26 becomes the part that accommodates the body 61 of the sensor 6, and the slots 263, 264, and 265 of the pocket 26 become the parts that accommodate the wiring 62 of the sensor 6. When the sensor 6 is accommodated in the pocket 26 of the bracket 2, the fourth surface 616 of the body 61 of the sensor 6 faces the radially inward side (arrow d direction), and the first surface 613 faces the radially outward side (arrow c direction). The first bottom surface 611 of the body 61 of the sensor 6 protrudes to one side in the direction of the rotation axis (arrow a direction). The first wiring 621, the second wiring 622 and the third wiring 623 extend and protrude from slots 263, 264 and 265 to one side (arrow a) in the direction of the rotation axis, respectively.

[0031] like Figure 7As shown, when the substrate 5 is positioned on one side of the bracket 2 in the direction of the rotation axis (arrow a direction), the first wiring 621, the second wiring 622, and the third wiring 623 of the sensor 6 are respectively inserted into holes 51, 52, and 53, which are through holes formed in the substrate 5. Therefore, the wiring 62 of the sensor 6 extends from the other side 2b of the bracket 2 toward one side 2a (towards one side in the direction of the rotation axis) and is electrically connected to the substrate 5. The bottom surface 611 of the body 61 of the sensor 6 is also exposed to one side in the direction of the rotation axis (arrow a direction) after the substrate 5 is positioned. In this embodiment, the bottom surface 611 of the body 61 of the sensor 6 is located slightly closer to one side in the direction of the rotation axis (arrow a direction) than the substrate 5. After the substrate 5 is positioned, the substrate 5 and the sensor 6 are covered by the cover 4 (see reference 4). Figure 1 ).

[0032] The following is for reference Figure 8 , Figure 9 as well as Figure 10 The configuration of sensor 6 and brush 35 is described in detail. Figure 8 As shown, the first brush 351 and the second brush 352 constituting the brush 35 are respectively housed in frames 216 and 217. In this way, the brush 35 is disposed on the other side 2b of the bracket 2. Both the first brush 351 and the second brush 352 are formed into approximately quadrangular prisms.

[0033] Wiring 351w and wiring 352w are respectively connected to the first brush 351 and the second brush 352. Wiring 351w extends to the outside of frame 216 via slit 216s, and wiring 352w extends to the outside of frame 217 via slit 217s.

[0034] The first brush 351 is subjected to radial inward force (in the direction of arrow d) by the elastic member 351s. In this embodiment, the elastic member 351s is a spring (elastic body) wound into a spiral shape and disposed on the post 271 provided on the bracket 2. The post 271 is a portion that protrudes to the other side in the direction of the rotation axis (in the direction of arrow b) and is disposed circumferentially between the frame 216 and the pocket 26.

[0035] The second brush 352 is subjected to radial inward force (in the direction of arrow d) by the elastic member 352s. In this embodiment, the elastic member 352s is a spring (elastic body) wound into a spiral shape and disposed on the post 272 provided on the bracket 2. The post 272 is a portion that protrudes to the other side in the direction of the rotation axis (in the direction of arrow b), and is configured to be symmetrical or substantially symmetrical with respect to the post 271 about the rotation axis S.

[0036] Figure 9 This is a three-dimensional sectional view showing a section obtained by cutting the motor 1 parallel to the rotating shaft S, passing through the sensor 6 and the first brush 351. (Example) Figure 9 As shown, sensor 6 and substrate 5 are disposed on one side 2a of bracket 2, and brushes 35 (first brush 351 and second brush 352) are disposed on the other side 2b of bracket 2. On the other side 2b of bracket 2, sensor 6 is covered by pocket 26 (in this embodiment, it is completely covered).

[0037] Figure 10 This is a three-dimensional sectional view showing a section obtained by cutting the motor 1 perpendicular to the rotating shaft S through the first brush 351 and the second brush 352. For example... Figure 10 As shown, brushes 35 (first brush 351 and second brush 352) contact the rectifier 34 from the radially outer side. On the other side 2b of the bracket 2, the path from the contact portion of the brushes 35 with the rectifier 34 to the sensor 6 is blocked by the inner circumference 266, side 267, and bottom 268 of the pocket 26. It should be noted that, according to Figure 10 It is also possible to visually identify the situation where multiple ribs 214 of the second outer periphery 213 of the bracket 2 are in contact with the inner peripheral surface 31i of the housing 31 of the motor body 3.

[0038] The following is for reference Figure 11 The overall structure of motor 1 will be described in detail below. Motor 1 has a motor body 3. Motor body 3 has a housing 31, a first bearing 32, a second bearing 33, a rectifier 34, a brush 35, a rotor 36, and a stator 37.

[0039] The housing 31 is a cylindrical component (e.g., cylindrical, rectangular, quadrilateral, or polygonal, or polygonal with multiple curved corners) formed of a magnetic material such as iron. The housing 31 houses the rotor 36. A cylindrical stator 37, serving as a permanent magnet, is fixed radially to the inner circumferential surface 31i of the housing 31. The end of the housing 31 on the other side (arrow b direction) in the direction of the rotation axis is covered by a bottom 311. A second retainer 312 protruding towards the other side (arrow b direction) in the direction of the rotation axis is provided in the central portion of the bottom 311. The second retainer 312 has: a cylindrical portion 312a protruding towards the other side (arrow b direction) in the direction of the rotation axis and surrounding the rotation axis S; and an annular portion 312b extending radially inward (arrow d direction) from the end of the cylindrical portion 312a on the other side in the direction of the rotation axis. The second retainer 312 supports the second bearing 33 (described later) on the inner side of the cylindrical portion 312a in the radial direction (in the direction of arrow d) and on one side of the annular portion 312b in the direction of the rotation axis (in the direction of arrow a).

[0040] In this embodiment, the stator 37 is a permanent magnet having multiple (e.g., four) magnetic poles. The stator 37 can be composed of multiple permanent magnets with multiple magnetic poles, or it can be composed of a single permanent magnet with multiple magnetic poles. The stator 37 is alternately magnetized with two different magnetic poles (N pole and S pole) in the circumferential direction.

[0041] The rotor 36 includes: an iron core 361 having multiple magnetic poles; and a coil 362 wound around the iron core 361. The rotor 36 is radially opposed to the stator 37. The iron core 361 of the rotor 36 is fixed to the rotation shaft S and rotates integrally with the rotation shaft S.

[0042] Along the rotation axis, a generally cylindrical rectifier 34 is disposed on one side of the rotor 36 (in the direction of arrow a). The rectifier 34 is fixed to the rotation axis S and rotates integrally with the rotation axis S. Multiple rectifier vanes 34c arranged circumferentially (see reference) of the rectifier 34... Figure 10 It is energized by contacting the brush 35.

[0043] Along the rotation axis, a generally disk-shaped magnet 7 is disposed on one side of the rectifier 34 (in the direction of arrow a). The magnet 7 is fixed to the rotation axis S and rotates integrally with it. The magnet 7 is a permanent magnet with multiple magnetic poles. The magnet 7 can be composed of multiple permanent magnets with multiple magnetic poles, or it can be composed of a single permanent magnet with multiple magnetic poles. The magnet 7 is alternately magnetized with two different magnetic poles (N pole and S pole) in the circumferential direction.

[0044] The arrangement of the magnet 7 along its rotation axis overlaps with the arrangement of the disk portion 211 of the bracket 2 along its rotation axis. The magnet 7 is radially opposed to the inner circumferential surface 211i of the disk portion 211 of the bracket 2. Furthermore, the arrangement of the magnet 7 along its rotation axis overlaps with the arrangement of the sensor 6 (specifically, the body 61 of the sensor 6) along its rotation axis. That is, the magnet 7 is radially opposed to the sensor 6 (specifically, the body 61 of the sensor 6) across the bracket 2. Therefore, the sensor 6 can detect the magnetic flux or changes in magnetic flux of the magnet 7.

[0045] In the direction of rotation, a first bearing 32 is disposed on one side of the magnet 7 (in the direction of arrow a). In this embodiment, the first bearing 32 is a ball bearing having an inner ring 321, an outer ring 322, and rolling elements. It should be noted that the first bearing 32 is not limited to a ball bearing, and may also be various other bearings such as sleeve bearings.

[0046] The first bearing 32 is radially disposed inside the cylindrical portion 241 of the first retainer 24 of the bracket 2 (in the direction of arrow d). The inner ring 321 of the first bearing 32 is bonded or pressed into the outer circumferential surface of the rotating shaft S. Thus, the inner ring 321 of the first bearing 32 is fixed to the rotating shaft S. The outer ring 322 of the first bearing 32 is bonded or pressed into the cylindrical portion 241 of the first retainer 24 of the bracket 2. In this way, the first bearing 32 supports the rotating shaft S so that it can rotate relative to the bracket 2.

[0047] In the direction of rotation, a second bearing 33 is disposed on the other side of the rotor 36 (in the direction of arrow b). In this embodiment, the second bearing 33 is a ball bearing having an inner ring 331, an outer ring 332, and rolling elements. It should be noted that the second bearing 33 is not limited to a ball bearing, and may also be various other bearings such as a sleeve bearing.

[0048] The second bearing 33 is radially disposed inside the cylindrical portion 312a of the second retainer 312 of the housing 31 (in the direction of arrow d). The inner ring 331 of the second bearing 33 is bonded or pressed into the outer circumferential surface of the rotating shaft S. Thus, the inner ring 331 of the second bearing 33 is fixed to the rotating shaft S. The outer ring 332 of the second bearing 33 is bonded or pressed into the cylindrical portion 312a of the second retainer 312 of the housing 31. In this way, the second bearing 33 supports the rotating shaft S so that it can rotate relative to the housing 31.

[0049] The motor 1 in this embodiment is a brushed DC motor with the above configuration. When current flows sequentially from wirings 351w and 352w connected to a power source or the like through brush 35, rectifier 34, and coil 362, rotor 36 and rotating shaft S begin to rotate. Rectifier 34 rotates together with rotating shaft S, thereby switching the rectifier segments 34c contacted by brush 35, and rotor 36 continues to rotate. Sensor 6 detects the magnetic flux from magnet 7, which rotates together with rotating shaft S, and the signal output from sensor 6 is input to substrate 5.

[0050] In motor 1, sensor 6 and substrate 5 are disposed on one side 2a of bracket 2, and brushes 35 (first brush 351 and second brush 352) are disposed on the other side 2b of bracket 2. On the other side 2b of bracket 2, sensor 6 is covered by the inner periphery 266, side 267, and bottom 268 of pocket 26. In this way, the path from the contact portion of brush 35 and rectifier 34 to sensor 6 is blocked by bracket 2, thus preventing metal powder generated at the contact portion of brush 35 and rectifier 34 due to friction from adhering to sensor 6 and substrate 5. Furthermore, in motor 1, sensor 6 and substrate 5 are covered together by cover 4. Therefore, the adhesion of other dust and the like to sensor 6 is also suppressed.

[0051] In motor 1, the second outer periphery 213 of bracket 2 contacts the inner peripheral surface 31i of housing 31 of motor body 3 via multiple ribs 214. As a result, vibrations of motor body 3 are less likely to propagate to sensor 6, thus improving the accuracy of sensor 6.

[0052] In motor 1, substrate 5 is disposed on one surface 2a of bracket 2. As a result, the overall structure including motor body 3 and substrate 5 is miniaturized.

[0053] In motor 1, sensor 6 can be installed after bracket 2 is attached to motor body 3. Therefore, the installation of sensor 6 is simple.

[0054] In motor 1, the inner circumference 266 of pocket 26 is located on the magnet 7 side relative to the wall 215 of bracket 2. That is, the portion 215n of pocket 26 protrudes radially inward (in the direction of arrow d) from the wall 215 of bracket 2. As a result, sensor 6 can be configured closer to magnet 7, and the accuracy of sensor 6 is improved.

[0055] The preferred embodiments of the motor of the present invention have been described above, but the motor of the present invention is not limited to the configuration of the above embodiments. Hereinafter, examples of other configurations that can be used in the motor of the present invention will be described.

[0056] In the motor of the present invention, the sensor may be indirectly supported on one side of the bracket via other components. Furthermore, in the motor of the present invention, the brush may be indirectly supported on the other side of the bracket via other components. The number of wires for the sensor in the motor of the present invention may be two or more. In the motor of the present invention, the outer periphery of the bracket may be in surface contact with the inner periphery of the motor body housing. In the motor of the present invention, the substrate and the bracket may be separately configured. In the motor of the present invention, the wall of the bracket may be located closer to the magnet side than the inner periphery of the pocket.

[0057] Furthermore, those skilled in the art can appropriately modify the motor of the present invention based on previously known insights, and can change the shape, size, and combination of various configurations. If the invention is still achieved through such modifications, it is naturally included within the scope of the present invention.

[0058] Explanation of reference numerals in the attached figures 1: Motor; 2: Bracket; 2a: One side; 2b: The other side; 215: Wall; 26: Pocket; 266: Inner perimeter; 267: Side; 268: Bottom; 32: Bearing; 34: Rectifier; 35: Brush; 5: Substrate; 6: Sensor; 61: Body; 62: Wiring; 7: Magnet; S: Rotating shaft.

Claims

1. A motor, comprising: Rotation axis; The bracket is formed of a non-magnetic material; A bearing supports the rotating shaft so that it can rotate relative to the bracket; Rectifier; A magnet is fixed to the rotating shaft; The sensor is disposed on one surface of the bracket in the direction of rotation axis; and The brush is disposed on the other side of the bracket in the direction of the rotation axis. The sensor detects the magnetic flux of the magnet.

2. The motor according to claim 1, wherein, The motor includes a base plate disposed on one side of the bracket. The sensor is electrically connected to the substrate.

3. The motor according to claim 1 or 2, wherein, The bracket is provided with a pocket for accommodating the sensor. The pocket opens on one side of the bracket. The pocket has: The inner circumference is radially opposed to the magnet; Side; and bottom, The sensor is surrounded by the inner periphery, the side, and the bottom of the pocket.

4. The motor according to claim 3, wherein, The sensor has a main body and wiring. The pocket has a portion for accommodating the body of the sensor and a portion for accommodating the wiring of the sensor.

5. The motor according to claim 4, wherein, The wiring of the sensor extends from the other side of the bracket toward the first side and is electrically connected to the substrate.

6. The motor according to any one of claims 3 to 5, wherein, The bracket has a wall in the radial direction that is opposite to the rectifier. The inner periphery of the pocket is located on the magnet side relative to the wall.

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