JP2005318687A - Brushless motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a brushless motor in which a sensor magnet for detecting the position of a rotor is engaged with a rotating shaft so as to be loose-fitted thereto, and which can suppress the backlash of the sensor magnet to the rotating shaft while preventing the breakage of the sensor magnet caused by the engagement. <P>SOLUTION: A mounting part 17 of a cross-sectional D shape is formed at the lower end of the rotary shaft 10. The mounting hole 15c of an axially seen D shape for engaging the mounting part 17 is formed at the sensor magnet body 15a of the sensor magnet 15. Further, a protruding part 15k is formed along a direction perpendicular to a planer surface 15d through the axial line L1 of the sensor magnet 15 on a contact surface 15j contacted with the lower surface of the sensor magnet body 15a, that is, the abutment surface 15j which abuts with a release preventive washer 16. Further, when the sensor magnet 15 is mounted at the mounting part, the protruding part 15k makes the axial line L1 (axial line of the mounting hole 15c) of the sensor magnet 15 incline to the axial line L2 of the rotary shaft 10. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a brushless motor, and more particularly to a mounting structure of a sensor magnet mounted on a rotating shaft of a brushless motor.

  2. Description of the Related Art Conventionally, a sensor magnet for detecting the rotational position of a rotor is attached to a rotation shaft of a rotor provided in a brushless motor. The sensor magnet has a mounting hole into which the rotation shaft is inserted. And the internal diameter of this attachment hole is formed larger than the outer diameter of the mounting part to which a sensor magnet is attached in a rotating shaft. That is, the mounting hole and the rotating shaft are fitted with a clearance fit. This is based on the results of considering workability when mounting the sensor magnet on the mounting portion, preventing damage to the sensor magnet due to mounting, and dimensional tolerances of the outer diameter of the mounting portion and the inner diameter of the mounting hole.

  However, as described above, if the mounting hole and the rotating shaft are fitted with a clearance fit, the sensor magnet rattles in the rotational direction with respect to the mounting portion during rotation of the rotor and is detected by the sensor magnet. In some cases, the rotational position of the rotor is advanced in the rotational direction or delayed. As a result, there has been a problem that the timing of energization performed in accordance with the rotational position of the rotor is deviated, resulting in variations in motor characteristics and noise.

  Therefore, Patent Document 1 discloses a brushless motor having a configuration that prevents rattling between the mounting hole of the sensor magnet and the mounting portion of the rotating shaft. The brushless motor disclosed in Patent Document 1 is used as a blower motor of a vehicle air conditioner. The rotor of this brushless motor includes a rotating shaft that is rotatably supported by a stator having an exciting coil. A mounting portion to which a sensor magnet for detecting the rotational position of the rotor is fitted is formed at the lower end portion of the rotating shaft. This mounting portion has a D-shaped cross section. In the center of the sensor magnet, a substantially D-shaped mounting hole that fits into the mounting portion is formed.

  The sensor magnet is held so as not to fall out of the mounting portion by a metal plate disposed in close contact with the upper surface thereof. This metal plate is formed to have substantially the same diameter as the outer diameter of the sensor magnet, and a substantially D-shaped insertion hole into which the mounting portion is inserted is formed at the center. An elastic piece extending in the axial direction of the metal plate is cut and raised at the straight portion of the insertion hole. The elastic piece is interposed in a gap formed by the flat surface portion of the mounting portion and the flat surface portion of the mounting hole, abuts on both flat surface portions, and further urges the flat surface portions away from each other by the elastic force. doing. In this way, the outer peripheral surface of the mounting portion and the inner peripheral surface of the mounting hole are in close contact with each other, and the sensor magnet is prevented from rattling with respect to the mounting portion while the rotor is rotating.

Further, Patent Document 1 discloses a configuration in which a plurality of hemispherical convex portions are formed along the axial direction on the flat portion of the mounting hole as a configuration for preventing the sensor magnet from rattling with respect to the mounting portion. . When the mounting portion is inserted into such a mounting hole, the convex portion elastically deforms between the flat portion of the mounting hole and the flat portion of the mounting portion, and the convex portion is flattened by the elastic force. The portion and the flat portion of the mounting portion are biased in a direction away from each other. As a result, the outer peripheral surface of the mounting portion and the inner peripheral surface of the mounting hole are brought into close contact with each other, and the sensor magnet is prevented from rattling with respect to the mounting portion. The sensor magnet is prevented from falling off the rotating shaft by a toothed washer fixed to the lower end of the sensor magnet.
JP-A-11-2899736

  However, in the brushless motor disclosed in Patent Document 1, in order to prevent rattling against the mounting portion of the sensor magnet, the elasticity by the elastic piece of the metal plate or the convex portion formed on the flat portion of the mounting hole. Utilizing power. The sensor magnet is prevented from rattling against the mounting portion of the sensor magnet by the elastic force of the elastic piece, and is prevented from falling off the rotating shaft by the elastic force. Great power is applied. Further, when the mounting portion is inserted into the mounting hole in which the convex portion is formed, the convex portion is elastically deformed, so that a large force is applied to the sensor magnet in the direction of increasing the inner diameter of the mounting hole. Therefore, there is a problem that the sensor magnet may be damaged when a large force is applied to the sensor magnet.

  The present invention has been made in view of such circumstances, and is a brushless motor that fits a sensor magnet for detecting the position of a rotor with a clearance fit with respect to a rotating shaft, and is a sensor magnet by fitting. An object of the present invention is to provide a brushless motor that can prevent rattling of a sensor magnet with respect to a rotating shaft while preventing breakage of the sensor magnet.

  In order to solve the above-mentioned problem, an invention according to claim 1 corresponds to the mounting shaft provided on the rotor, the rotating shaft having a mounting portion having a non-circular cross section and having at least one flat portion, and the mounting portion. A mounting hole having a non-circular shape when viewed in the axial direction and having at least one flat surface portion, and a mounting portion of the rotating shaft fitted into the mounting hole by a clearance fit to be mounted on the rotating shaft A magnet, and a retaining member that is attached to the rotating shaft and contacts the sensor magnet to support the sensor magnet in the axial direction, and detects a change in the magnetic field of the sensor magnet that rotates with the rotation of the rotor. A brushless motor for detecting the rotational position of the rotor, wherein the sensor magnet is tilted so that the axis of the mounting hole is tilted with respect to the axis of the rotating shaft, and the flat portion of the mounting hole and the front And a flat portion of the mounting portion of the rotary shaft with a gradient maintaining means for maintaining causes line contact.

  According to a second aspect of the present invention, the rotor includes a rotating shaft provided with a mounting portion having a D-shaped cross section, and a mounting hole corresponding to the mounting portion and having a D-shape when viewed in the axial direction. A mounting portion of the rotating shaft is fitted with a clearance fit, and a sensor magnet is mounted on the rotating shaft, and is mounted on the rotating shaft and contacts the sensor magnet to support the sensor magnet in the axial direction. A brushless motor that detects a rotational position of the rotor by detecting a change in the magnetic field of the sensor magnet that rotates with the rotation of the rotor. The sensor magnet is tilted so that the axis is tilted, and tilt maintaining means for maintaining the plane portion of the mounting hole and the plane portion of the mounting portion of the rotating shaft while maintaining line contact is provided.

  According to a third aspect of the present invention, in the brushless motor according to the second aspect, the inclination maintaining means is a convex portion formed on a contact surface of the sensor magnet that contacts the retaining member, and the convex The sensor magnet is inclined by the portion.

  According to a fourth aspect of the present invention, in the brushless motor according to the third aspect, the convex portion is formed on the opposite side of the sensor magnet with respect to the flat portion of the mounting hole across the axis of the sensor magnet. ing.

  According to a fifth aspect of the present invention, in the brushless motor according to the second aspect, the sensor magnet includes a flange portion extending in a radial direction of the rotating shaft, and the inclination maintaining means is provided on the mounting hole. It is a collar part formed with a relatively thin wall thickness along a straight line orthogonal to the plane part.

  According to a sixth aspect of the present invention, in the brushless motor according to the second aspect, the inclination maintaining means changes in an angle with respect to the plane portion of the mounting portion with respect to a plane perpendicular to the plane portion of the mounting portion. The retaining member that is inclined to the direction and fixed to the mounting portion.

  According to a seventh aspect of the present invention, in the brushless motor according to the second aspect, the inclination maintaining means is formed on a contact surface that contacts the retaining member in the sensor magnet and accommodates the retaining member. It is a countersink part, and the bottom surface of the countersink part is formed to be inclined with respect to a plane perpendicular to the plane part of the mounting hole in a direction in which an angle with respect to the plane part of the mounting hole changes.

  According to an eighth aspect of the present invention, in the brushless motor according to any one of the first to seventh aspects, the base end portion of the mounting portion has a surface orthogonal to the flat portion of the mounting portion. A step portion is provided, and the sensor magnet is in contact with the surface.

(Function)
According to the first aspect of the invention, the axis of the mounting hole of the sensor magnet is inclined with respect to the axis of the rotation shaft by the inclination maintaining means. For this reason, the plane portion of the mounting portion that directly transmits the rotation of the rotation shaft to the sensor magnet and the plane portion of the mounting hole of the sensor magnet are in line contact and kept in line contact. Therefore, even if the mounting portion of the rotating shaft and the mounting hole of the sensor magnet are fitted with a clearance fit, the sensor magnet is prevented from rattling with respect to the rotating shaft when the rotating shaft rotates. Further, since the tilt maintaining means only tilts the axis of the mounting hole of the sensor magnet with respect to the axis of the rotation shaft, there is no possibility that a large force is applied to the sensor magnet. Therefore, rattling of the sensor magnet with respect to the rotation shaft can be suppressed while preventing damage to the sensor magnet due to the fitting between the mounting portion and the mounting hole.

  According to the invention described in claim 2, the axis of the sensor magnet mounting hole is inclined with respect to the axis of the rotation shaft by the inclination maintaining means. For this reason, the plane portion of the mounting portion that directly transmits the rotation of the rotation shaft to the sensor magnet and the plane portion of the mounting hole of the sensor magnet are in line contact and kept in line contact. Therefore, even if the mounting portion of the rotating shaft and the mounting hole of the sensor magnet are fitted with a clearance fit, the sensor magnet is prevented from rattling with respect to the rotating shaft when the rotating shaft rotates. Further, since the tilt maintaining means only tilts the axis of the mounting hole of the sensor magnet with respect to the axis of the rotation shaft, there is no possibility that a large force is applied to the sensor magnet. Therefore, rattling of the sensor magnet with respect to the rotation shaft can be suppressed while preventing damage to the sensor magnet due to the fitting between the mounting portion and the mounting hole.

  According to the third aspect of the present invention, the inclination maintaining means is a convex portion formed on the contact surface that contacts the retaining washer in the sensor magnet. With a simple configuration that merely forms such a convex portion, the plane portion of the mounting hole and the plane portion of the mounting portion are maintained in line contact with each other, and rattling with respect to the rotation axis of the sensor magnet is suppressed.

  According to invention of Claim 4, the convex part is formed in the other side on both sides of the axis line of a sensor magnet with respect to the plane part of an attachment hole. For this reason, the sensor magnet causes the flattened portion of the mounting portion to abut the side of the flattened portion of the mounting hole on the side of the retaining washer among the sides orthogonal to the axial direction of the sensor magnet. Therefore, rattling with respect to the rotation axis of the sensor magnet is suppressed more stably.

  According to the fifth aspect of the present invention, the inclination maintaining means is a flange portion that is formed with a relatively thin wall thickness along a straight line perpendicular to the flat surface portion of the mounting hole. Since the thickness of the collar portion is gradually reduced along the straight line, when the collar portion is supported in the axial direction by the retaining member, the axis of the sensor magnet mounting hole is aligned with the axis of the rotating shaft. On the other hand, it inclines to the side where the thickness is formed thinly in the buttocks. Therefore, the flat portion of the mounting hole and the flat portion of the mounting portion are maintained in contact with each other with a simple configuration in which the thickness of the collar portion is formed relatively gradually along the straight line. Shaking with respect to the rotation axis of the magnet is suppressed.

  According to the sixth aspect of the present invention, the retaining member that is the inclination maintaining means is inclined and fixed in a direction in which the angle with respect to the plane portion of the mounting portion changes with respect to a plane perpendicular to the plane portion of the mounting portion. Is done. Therefore, the sensor magnet supported in the axial direction by the retaining member is also supported by being inclined in a direction in which the angle with respect to the plane portion of the mounting portion changes with respect to a plane perpendicular to the plane portion of the mounting portion. That is, the sensor magnet is supported by inclining the axis of the mounting hole of the sensor magnet with respect to the axis of the rotation shaft. Therefore, the retaining member can be mounted on the flat portion of the mounting hole with a simple configuration by simply inclining and fixing the retaining member to the surface perpendicular to the flat portion of the mounting portion in a direction in which the angle of the mounting portion with respect to the flat portion changes. The flat part of the part is kept in contact with the line, and the backlash of the sensor magnet with respect to the rotation axis is suppressed.

  According to the seventh aspect of the present invention, the bottom surface of the countersunk portion that is the tilt maintaining means is inclined in a direction in which the angle with respect to the plane portion of the mounting hole changes with respect to a plane perpendicular to the plane portion of the mounting hole. Is formed. Therefore, when the retaining member is accommodated in the countersunk portion, the sensor magnet is fixed while being inclined with respect to a plane perpendicular to the flat portion of the mounting hole. That is, the sensor magnet is supported by inclining the axis of the sensor magnet mounting hole with respect to the axis of the rotation shaft. Accordingly, the flat surface portion of the mounting hole has a simple configuration in which the bottom surface simply forms a countersink portion inclined in a direction in which the angle with respect to the flat surface portion of the mounting hole changes with respect to a surface perpendicular to the flat surface portion of the mounting hole. And the flat portion of the mounting portion are in line contact with each other and maintained, and rattling of the sensor magnet with respect to the rotation axis is suppressed.

  According to the invention described in claim 8, the base end portion of the mounting portion is provided with the step portion having a surface orthogonal to the flat portion of the mounting portion. And since the sensor magnet is contact | abutting to the said surface orthogonal to the plane part of a mounting part, the shakiness of the axial direction of a sensor magnet is suppressed.

  According to the present invention, a brushless motor that fits a sensor magnet for detecting the position of a rotor with a clearance fit with respect to a rotating shaft, while preventing the sensor magnet from being damaged by the fitting, Thus, it is possible to provide a brushless motor in which rattling with respect to the rotation axis is suppressed.

(First embodiment)
A first embodiment of the present invention will be described below with reference to the drawings.
FIG. 1 shows a brushless motor 1 according to this embodiment. The brushless motor 1 is used as a blower motor of a vehicle air conditioner. As shown in FIG. 1, the brushless motor 1 includes a substantially disk-shaped motor holder 2, and a stator 3 is fixed to the upper surface of the motor holder 2. The stator 3 includes a center piece 4, a core 5, and an exciting coil 6 in which a winding is wound around the core 5.

  A rotor 7 is rotatably supported on the stator 3. The rotor 7 includes a bell-shaped yoke 8, a plurality of magnets 9 fixed to the inner peripheral surface of the yoke 8, and a rotating shaft 10 that is press-fitted into the center of the bottom of the yoke 8. The rotary shaft 10 is rotatably supported at the center portion of the center piece 4 via bearings 11 and 12. A fan 13 is attached to the upper end portion of the rotating shaft 10 so as to be rotatable integrally with the rotating shaft 10.

  A sensor magnet 15 for detecting the rotational position of the rotor 7 is mounted on the lower end portion of the rotating shaft 10 together with a hall element 24 described later. The sensor magnet 15 is supported in the axial direction by a retaining washer 16 as a retaining member attached to the rotary shaft 10 on the lower end side of the sensor magnet 15.

  As shown in FIG. 2 (a), in order to mount the sensor magnet 15 on the lower end portion of the rotating shaft 10, a mounting portion 17 having a D-shaped cross section in which a part of the rotating shaft 10 is chamfered (FIG. 2 ( b)) is formed. The mounting portion 17 includes a flat portion 17 a whose chamfered portion is parallel to the axial direction of the rotary shaft 10. Further, a stepped portion 17c having a surface 17b orthogonal to the flat surface portion 17a is formed at the base end portion of the mounting portion 17.

  The sensor magnet 15 includes a sensor magnet main body 15a formed in a disk shape, and a boss portion 15b extending upward from the upper center of the sensor magnet main body 15a. As shown in FIG. 2 (c), a mounting hole 15c for fitting the mounting portion 17 of the rotating shaft 10 is formed in the central portion of the sensor magnet main body 15a. The mounting hole 15 c has an axis that is equal to the axis L 1 of the sensor magnet 15. The mounting hole 15c has a D shape when viewed from the axial direction corresponding to the mounting portion 17, and a portion corresponding to the straight portion of the D shape is a flat portion 15d. The flat portion 15 d is formed in parallel with the axial direction of the sensor magnet 15. Further, as shown in FIG. 2A, the boss portion 15b includes an insertion hole 15e having a circular shape communicating with the mounting hole 15c. A step portion 15g having a surface 15f orthogonal to the planar portion 15d is formed at a joint portion between the insertion hole 15e and the mounting hole 15c. The step portion 15g includes a corner portion 15h chamfered along the upper end of the flat portion 15d.

  The inner diameter of the insertion hole 15e is formed to be slightly larger than the outer diameter of the cylindrical portion of the rotating shaft 10 in order to prevent the sensor magnet 15 from being damaged. For the same reason, the inner periphery of the mounting hole 15 c is formed slightly larger than the outer periphery of the mounting portion 17 of the rotating shaft 10. Accordingly, the sensor magnet 15 is mounted on the rotating shaft 10 by fitting the mounting portion 17 into the mounting hole 15c with a clearance fit.

  On the lower surface of the sensor magnet body 15a, that is, on the contact surface 15j that contacts the retaining washer 16, a convex portion 15k as an inclination maintaining means is formed integrally with the sensor magnet 15. As shown in FIG. 2C, the convex portion 15k is formed along a direction that passes through the axis L1 of the sensor magnet 15 and is orthogonal to the planar portion 15d. Further, the convex portion 15k is formed on the opposite side of the sensor magnet 15 across the axis L1 of the sensor magnet 15 with respect to the flat portion 15d.

  As shown in FIG. 2B, the retaining washer 16 is a so-called toothed washer. The retaining washer 16 has a disk shape, and has a substantially circular press-fit hole 16b formed by a plurality of teeth 16a at the center thereof. The retaining washer 16 is fixed perpendicularly to the rotary shaft 10 in a portion that penetrates from the mounting hole 15 c of the mounting portion 17. At this time, the retaining washer 16 is mounted on the rotary shaft 10 by pressing the tips of the plurality of teeth 16a against the outer peripheral surface of the mounting portion 17 other than the flat portion 17a. By being attached to the rotating shaft 10 in this manner, the retaining washer 16 prevents the sensor magnet 15 from falling off the rotating shaft 10.

  When the sensor magnet 15 is thus mounted, the convex portion 15k is placed on the upper surface of the retaining washer 16. At this time, since the mounting portion 17 and the mounting hole 15c are fitted with a clearance fit, the axis L1 of the sensor magnet 15 (the axis of the mounting hole 15c) is inclined with respect to the axis L2 of the rotating shaft 10. . Therefore, the sensor magnet 15 is held in a state in which the lower side, that is, the side 15m on the retaining washer 16 side of the side in the direction perpendicular to the axial direction of the sensor magnet 15 is in contact with the plane portion 17a in the plane portion 15d. . At the same time, the sensor magnet 15 is opposite to the side 15m across the axis L1 of the sensor magnet 15 and opposite to the side 15m in the axial direction, that is, the opening of the sensor magnet 15, that is, the upper opening of the boss portion 15b. (Abutting portion 15 n) is held in a state where it abuts on the outer peripheral surface of the rotating shaft 10. As a result, the contact state between the flat surface portion 15d of the sensor magnet 15 and the flat surface portion 17a of the mounting portion 17 is always maintained, so that the sensor magnet 15 is mounted on the mounting portion 17 without rattling in the rotation direction. . In this case, the sensor magnet 15 is fitted to the mounting portion 17 with a clearance fit, and the plane portion 15d and the plane portion 17a are always in contact with each other with respect to the axis L2 of the rotary shaft 10. Because of the structure in which the axis L1 is inclined, the sensor magnet 15 is not applied with a large force. Furthermore, since the sensor magnet 15 is held in a state where the corner portion 15h of the step portion 15g is in contact with the surface 17b of the step portion 17c of the rotating shaft 10, the sensor magnet 15 is mounted without shaking in the axial direction.

  The magnet 9 of the rotor 7 is disposed on the inner peripheral surface of the yoke 8 with reference to the flat portion 17a of the mounting portion 17. The sensor magnet 15 is magnetized corresponding to the magnet 9 with reference to the flat portion 15d of the mounting hole 15c.

  As shown in FIG. 1, a circuit board 20 is disposed on the lower surface of the motor holder 2 so as to be positioned below the sensor magnet 15. The circuit board 20 is fixed to the motor holder 2 with screws 21 and is covered with a lower case 22 attached to the motor holder 2. The circuit board 20 is provided with an excitation circuit 23 for supplying a drive current to the excitation coil 6 in order to generate a rotating magnetic field in the stator 3. The circuit board 20 is provided with a hall element 24 in the vicinity of the outer periphery of the sensor magnet 15. The Hall element 24 detects a magnetic field change due to the rotation of the sensor magnet 15 and outputs a detection signal to the excitation circuit 23.

  In the brushless motor 1 configured as described above, when a driving current is supplied from the exciting circuit 23 to the exciting coil 6, a rotating magnetic field is generated in the stator 3, and the rotor 7 is driven and rotated based on the rotating magnetic field. And the fan 13 is rotated with rotation of the rotor 7, and ventilation operation | movement is performed. The excitation circuit 23 detects the position of the magnet 9 of the rotor 7 based on the detection signal based on the rotation of the sensor magnet 15 output from the Hall element 24, and the position of the magnet 9 and the timing for exciting the excitation coil 6 are optimal. The drive current supplied to the exciting coil 6 is controlled so that

  (1) The axis L1 of the sensor magnet 15 (the axis of the mounting hole 15c) is inclined with respect to the axis L2 of the rotating shaft 10 by the convex portion 15k. Therefore, the planar portion 17a that directly transmits the rotation of the rotating shaft 10 to the sensor magnet 15 and the planar portion 15d of the mounting hole 15c are kept in line contact and in a line contact state. Therefore, even if the mounting portion 17 of the rotating shaft 10 and the mounting hole 15c of the sensor magnet 15 are fitted with a clearance fit, the sensor magnet 15 rattles against the rotating shaft 10 when the rotating shaft 10 rotates. It is prevented. As a result, the rotation position of the rotor 7 detected using the sensor magnet 15 during the rotation of the rotor 7 is prevented from shifting in the rotation direction, and the excitation coil 6 is appropriately timed according to the rotation position of the rotor 7. Can be supplied with an exciting current.

  (2) Since the convex portion 15k only inclines the axis L1 of the sensor magnet 15 (the axis of the mounting hole 15c) with respect to the axis L2 of the rotating shaft 10, there is no possibility that a large force is applied to the sensor magnet 15. Therefore, rattling of the sensor magnet 15 with respect to the rotating shaft 10 can be suppressed while preventing damage to the sensor magnet 15 due to the fitting between the mounting portion 17 and the mounting hole 15c.

  (3) With a simple configuration in which the convex portion 15k is formed on the contact surface 15j, the side 15m of the flat surface portion 15d is brought into contact with the flat surface portion 17a to suppress rattling of the sensor magnet 15 with respect to the rotating shaft 10. can do.

  (4) The convex portion 15k is formed on the opposite side of the plane portion 15d across the axis L1 of the sensor magnet 15. For this reason, the sensor magnet 15 abuts the flat portion 17a with the lower portion of the side of the flat portion 15d perpendicular to the axial direction of the sensor magnet 15, that is, the side 15m on the retaining washer 16 side. Therefore, rattling of the sensor magnet 15 with respect to the rotating shaft 10 can be suppressed more stably.

  (5) The sensor magnet 15 has a side 15m of the flat portion 15d on the side of the retaining washer 16 and a side opposite to the side 15m across the axis L1 of the sensor magnet 15 and is opposite to the side 15m in the axial direction. The sensor magnet is held in a state where the two portions of the opening of the sensor magnet, that is, the upper opening (contact portion 15n) of the boss portion 15b are in contact with the rotating shaft 10. Therefore, the sensor magnet 15 is stably mounted on the mounting portion 17 even when the axis L1 of the sensor magnet 15 is inclined with respect to the axis L2 of the rotating shaft 10.

  (6) Since the sensor magnet 15 is held in a state where the corner portion 15h of the step portion 15g is in contact with the surface 17b of the step portion 17c of the rotating shaft 10, the sensor magnet 15 is prevented from rattling in the axial direction. Is done.

(Second Embodiment)
Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. In addition, about the structure similar to the said 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  The sensor magnet 30 of this embodiment is provided in the brushless motor 1 in place of the sensor magnet 15 of the first embodiment. As shown in FIG. 3, the sensor magnet 30 of the present embodiment includes a sensor magnet main body 30 a having a disc shape as an inclination maintaining means and a flange portion, and a boss portion 15 b. A mounting hole 30c for fitting the mounting portion 17 of the rotating shaft 10 is formed in the central portion of the sensor magnet body 30a. The mounting hole 30c is formed such that its axis is equal to the axis L3 of the sensor magnet 30. The mounting hole 30c has a D shape when viewed from the axial direction corresponding to the mounting portion 17, and a portion corresponding to the straight portion of the D shape is a flat portion 30d. The flat portion 30 d is formed in parallel with the axial direction of the sensor magnet 30.

  A step portion 30f having a surface 30e orthogonal to the plane portion 30d is formed at a joint portion between the insertion hole 15e of the boss portion 15b and the mounting hole 30c. The step portion 30f includes a corner portion 30g chamfered along the upper end of the flat surface portion 30d.

  The inner periphery of the mounting hole 30 c is formed to be slightly larger than the outer periphery of the mounting portion 17 of the rotating shaft 10 in order to prevent the sensor magnet 30 from being damaged. Therefore, the sensor magnet 30 is mounted on the rotating shaft 10 by fitting the mounting portion 17 into the mounting hole 30c with a clearance fit.

  The sensor magnet main body 30a is formed so as to have a relatively thin wall thickness along a straight line L4 orthogonal to the plane portion 30d. In the present embodiment, the sensor magnet body along the straight line L4 from the D-shaped curved portion side of the mounting hole 30c toward the flat surface portion 30d (from the left side to the right side in FIG. 3). The thickness of 30a is gradually reduced.

  The sensor magnet 30 configured as described above is mounted on the rotating shaft 10 by fitting the mounting portion 17 in the mounting hole 30c. The sensor magnet 30 is supported in the axial direction by a retaining washer 16. At this time, since the thickness of the sensor magnet body 30a is gradually reduced along the straight line L4, the axis L3 of the sensor magnet 30 is inclined to the side where the thickness of the sensor magnet body 30a is thin. Therefore, the axis L3 of the sensor magnet 30 (the axis of the mounting hole 30c) is inclined with respect to the axis L2 of the rotating shaft 10. As a result, the sensor magnet 30 is held in a state in which the lower side, that is, the side 30h on the retaining washer 16 side, of the side in the direction perpendicular to the axial direction of the sensor magnet 30 is in contact with the flat part 17a in the flat part 30d. The At the same time, the sensor magnet 30 is opposite to the side 30h across the axis L3 of the sensor magnet 30 and opposite to the side 30h in the axial direction, that is, the opening of the sensor magnet 30, that is, the upper opening of the boss portion 15b. (Abutting portion 15 n) is held in a state where it abuts on the outer peripheral surface of the rotating shaft 10. As a result, the contact state between the flat portion 30d of the sensor magnet 30 and the flat portion 17a of the mounting portion is always maintained, so that the sensor magnet 30 is mounted on the mounting portion 17 without rattling in the rotational direction. In this case, the sensor magnet 30 is mounted on the mounting portion 17 with a clearance fit, and the flat portion 30d and the flat portion 17a are always in contact with each other with respect to the axis L2 of the rotary shaft 10. Due to the structure in which the axis L3 is inclined and attached, no large force is applied to the sensor magnet 30. Further, since the sensor magnet 30 is held in a state where the corner portion 30g of the step portion 30f is in contact with the surface 17b of the step portion 17c of the rotating shaft 10, the sensor magnet 30 is mounted without shaking in the axial direction.

As described above, according to the present embodiment, in addition to the same effects as the effects (5) and (6) of the first embodiment, the following effects are obtained.
(1) Since the thickness of the sensor magnet body 30a is gradually reduced along the straight line L4, the axis L3 of the sensor magnet 30 (the axis of the mounting hole 30c) is relative to the axis L2 of the rotary shaft 10. It is inclined. Therefore, the flat surface portion 17a that directly transmits the rotation of the rotating shaft 10 to the sensor magnet 30 and the flat surface portion 30d of the mounting hole 30c are kept in line contact and in a line contact state. Therefore, even if the mounting portion 17 of the rotating shaft 10 and the mounting hole 30c of the sensor magnet 30 are fitted with a clearance fit, when the rotating shaft 10 rotates, the sensor magnet 30 moves relative to the rotating shaft 10. Shaking is prevented. As a result, the rotation position of the rotor 7 detected using the sensor magnet 30 during the rotation of the rotor 7 is prevented from being shifted in the rotation direction, and the excitation coil 6 is applied at an appropriate timing according to the rotation position of the rotor 7. An exciting current can be supplied.

  (2) By forming the sensor magnet body 30a thin along the straight line L4, the axis L3 of the sensor magnet 30 (the axis of the mounting hole 30c) is simply inclined with respect to the axis L2 of the rotary shaft 10. Therefore, there is no possibility that a large force is applied to the sensor magnet 30. Therefore, rattling of the sensor magnet 30 with respect to the rotating shaft 10 can be suppressed while preventing damage to the sensor magnet 30 due to the fitting between the mounting portion 17 and the mounting hole 30c.

  (3) The side 30h of the side in the direction perpendicular to the axial direction of the sensor magnet 30 is flat in the flat portion 30d with a simple configuration in which the thickness of the sensor magnet main body 30a is gradually reduced along the straight line L4. The backlash with respect to the rotating shaft 10 of the sensor magnet 30 can be suppressed by contacting the portion 17a.

(Third embodiment)
Hereinafter, a third embodiment of the present invention will be described with reference to the drawings. In addition, about the structure similar to the said 1st and 2nd embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  The sensor magnet 40 of this embodiment is provided in the brushless motor 1 in place of the sensor magnet 15 of the first embodiment. As shown in FIG. 4, the sensor magnet 40 of this embodiment includes a sensor magnet body 40a and a boss portion 15b. The sensor magnet body 40a has a disk shape and is formed with a constant thickness in the axial direction. A mounting hole 40c for fitting the mounting portion 17 of the rotating shaft 10 is formed at the center of the sensor magnet body 40a. The mounting hole 40c is formed such that its axis is equal to the axis L5 of the sensor magnet 40. The mounting hole 40c has a D shape when viewed from the axial direction corresponding to the mounting portion 17, and a portion corresponding to the straight portion of the D shape is a flat portion 40d. The flat portion 40 d is formed in parallel with the axial direction of the sensor magnet 40.

  A stepped portion 40f having a surface 40e orthogonal to the flat surface portion 40d is formed at a joint portion between the insertion hole 15e of the boss portion 15b and the mounting hole 40c. The stepped portion 40f includes a corner portion 40g chamfered along the upper end of the flat surface portion 40d.

  The inner periphery of the mounting hole 40 c is formed to be slightly larger than the outer periphery of the mounting portion 17 of the rotating shaft 10 in order to prevent the sensor magnet 40 from being damaged. Accordingly, the sensor magnet 40 is mounted on the rotating shaft 10 by fitting the mounting portion 17 into the mounting hole 40c with a clearance fit.

  The sensor magnet 40 configured as described above is mounted on the rotary shaft 10 by fitting the mounting portion 17 in the mounting hole 40c. The sensor magnet 40 is supported in the axial direction by a retaining washer 41 as an inclination maintaining means having the same shape as the retaining washer 16 of the first and second embodiments. At this time, the retaining washer 41 is fixed to the mounting portion 17 so as to incline in a direction in which the angle with respect to the plane portion 17a changes with respect to the surface S1 perpendicular to the plane portion 17a. In the present embodiment, the retaining washer 41 is fixed to the mounting portion 17 while being inclined from the surface S1 by lowering the flat portion 40d side downward with respect to the D-shaped curved portion side of the mounting hole 40c. Therefore, the sensor magnet 40 supported in the axial direction by the retaining washer 41 is also supported by being inclined with respect to the surface S1 in a direction in which the angle with respect to the flat portion 17a changes. That is, the sensor magnet 40 is supported by inclining the axis L5 of the sensor magnet 40 (the axis of the mounting hole 40c) with respect to the axis L2 of the rotating shaft 10. As a result, among the sides in the direction perpendicular to the axial direction of the sensor magnet 40 in the plane portion 40d, the lower side, that is, the side 40h on the retaining washer 41 side is held in contact with the plane portion 17a. At the same time, the sensor magnet 40 is opposite to the side 40h across the axis L5 of the sensor magnet 40 and is opposite to the side 40h in the axial direction, that is, the opening of the sensor magnet 40, that is, the upper opening of the boss portion 15b. (Abutting portion 15 n) is held in a state where it abuts on the outer peripheral surface of the rotating shaft 10. As a result, since the contact state between the flat surface portion 40d of the sensor magnet 40 and the flat surface portion 17a of the mounting portion 17 is always maintained, the sensor magnet 40 is mounted on the mounting portion 17 without rattling in the rotation direction. . In this case, the sensor magnet 40 is mounted on the mounting portion 17 with a clearance fit, and the flat surface portion 40d and the flat surface portion 17a are always in contact with each other with respect to the axis L2 of the rotary shaft 10. Due to the structure in which the axis L5 is inclined and attached, a large force is not applied to the sensor magnet 40. Furthermore, since the sensor magnet 40 is held in a state where the corner portion 40g of the step portion 40f is in contact with the surface 17b of the step portion 17c of the rotating shaft 10, the sensor magnet 40 is mounted without shaking in the axial direction.

As described above, according to the present embodiment, in addition to the same effects as the effects (5) and (6) of the first embodiment, the following effects are obtained.
(1) With respect to the axis L2 of the rotating shaft 10, the axis L5 of the sensor magnet 40 (of the mounting hole 40c) is tilted with respect to the plane S1 perpendicular to the plane part 17a and fixed to the mounting part 17. The axis) is tilted. Therefore, the flat surface portion 17a that directly transmits the rotation of the rotating shaft 10 to the sensor magnet 40 and the flat surface portion 40d of the mounting hole 40c are kept in line contact and in a line contact state. Therefore, even if the mounting portion 17 of the rotating shaft 10 and the mounting hole 40c of the sensor magnet 40 are fitted with a clearance fit, when the rotating shaft 10 rotates, the sensor magnet 40 moves relative to the rotating shaft 10. Shaking is prevented. As a result, the rotation position of the rotor 7 detected using the sensor magnet 40 during the rotation of the rotor 7 is prevented from shifting in the rotation direction, and the excitation coil 6 is applied to the excitation coil 6 at an appropriate timing according to the rotation position of the rotor 7. An exciting current can be supplied.

  (2) The retaining washer 41 is tilted with respect to the surface S1 perpendicular to the flat surface portion 17a and fixed to the mounting portion 17, so that the axis L5 (mounting hole) of the sensor magnet 40 with respect to the axis L2 of the rotating shaft 10 is secured. Therefore, there is no possibility that a large force is applied to the sensor magnet 40. Therefore, rattling of the sensor magnet 40 with respect to the rotating shaft 10 can be suppressed while preventing damage to the sensor magnet 40 due to the fitting between the mounting portion 17 and the mounting hole 40c.

  (3) The retaining washer 41 is simply configured to be inclined and fixed to the mounting portion 17 with respect to a plane perpendicular to the planar portion 17a in a direction in which the angle with respect to the planar portion 17a is changed. The side 15m can be brought into contact with the flat surface portion 17a to prevent rattling of the sensor magnet 40 with respect to the rotating shaft 10.

(Fourth embodiment)
Hereinafter, a fourth embodiment of the present invention will be described with reference to the drawings. In addition, about the structure similar to the said 1st thru | or 3rd embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  The sensor magnet 50 of the present embodiment is provided in the brushless motor 1 in place of the sensor magnet 15 of the first embodiment. As shown in FIG. 5, the sensor magnet 50 of this embodiment includes a sensor magnet body 50a and a boss portion 15b. A mounting hole 50c for fitting the mounting portion 17 of the rotating shaft 10 is formed in the central portion of the sensor magnet main body 50a. The mounting hole 50c is formed so that its axis is equal to the axis L6 of the sensor magnet 50. The mounting hole 50c has a D shape when viewed from the axial direction corresponding to the mounting portion 17, and a portion corresponding to the straight portion of the D shape is a flat portion 50d. The flat portion 50 d is formed in parallel with the axial direction of the sensor magnet 50.

  A step portion 50f having a surface 50e orthogonal to the flat surface portion 50d is formed at a joint portion between the insertion hole 15e and the mounting hole 50c of the boss portion 15b. The step portion 50f includes a corner portion 50g chamfered along the upper end of the flat portion 50d.

  The inner periphery of the mounting hole 50 c is formed to be slightly larger than the outer periphery of the mounting portion 17 of the rotating shaft 10 in order to prevent the sensor magnet 50 from being damaged. Accordingly, the sensor magnet 50 is mounted on the rotary shaft 10 by fitting the mounting portion 17 into the mounting hole 50c with a clearance fit.

  On the contact surface 50h that contacts the retaining washer 16 in the sensor magnet 50, a countersink portion 50j as an inclination maintaining means is formed at the center thereof. The counterbore 50j is a recess having a diameter slightly larger than the diameter of the retaining washer 16. The bottom surface 50k of the counterbore 50j is formed so as to be inclined with respect to the plane S2 perpendicular to the plane 50d in a direction in which the angle with respect to the plane 50d changes. In the present embodiment, the bottom surface 50k of the counterbore 50j is such that the flat surface portion 50d side rises upward with respect to the D-shaped curved portion side of the mounting hole 50c, in other words, the D-shaped curved portion side of the mounting hole 50c. On the other hand, the countersunk portion 50j is formed deeper on the flat surface portion 50d side. The counter-pasting portion 50j accommodates the retaining washer 16 that is mounted perpendicular to the axis L2 of the rotating shaft 10 when the sensor magnet 50 is supported in the axial direction by the retaining washer 16. .

  The sensor magnet 50 configured as described above is mounted on the rotary shaft 10 by fitting the mounting portion 17 in the mounting hole 50c. The sensor magnet 50 is supported in the axial direction by the retaining washer 16. At this time, since the bottom surface 50k of the countersunk portion 50j is formed to be inclined with respect to the surface S2 perpendicular to the flat surface portion 17a, when the retaining washer 16 is accommodated in the countersink portion 50j, the sensor magnet 50 Is attached to the rotary shaft 10 while being inclined with respect to the surface S2. Then, the axis L6 of the sensor magnet 50 (the axis of the mounting hole 50c) is inclined with respect to the axis L2 of the rotating shaft 10, and the sensor magnet 50 has a side in a direction perpendicular to the axial direction of the sensor magnet 50 in the flat portion 50d. Among them, the lower side, that is, the side 50m on the side of the retaining washer 16 is held in contact with the flat surface portion 17a. At the same time, the sensor magnet 50 has an opening on the opposite side of the side 50m across the axis L6 of the sensor magnet 50 and opposite to the side 50m in the axial direction, that is, an upper opening of the boss portion 15b. (Abutting portion 15 n) is held in a state where it abuts on the outer peripheral surface of the rotating shaft 10. As a result, the contact state between the flat surface portion 50d of the sensor magnet 50 and the flat surface portion 17a of the mounting portion 17 is always maintained, so that the sensor magnet 50 is mounted on the mounting portion 17 without rattling in the rotational direction. . In this case, the sensor magnet 50 is mounted on the mounting portion 17 with a clearance fit, and the flat portion 50d and the flat portion 17a are always in contact with each other with respect to the axis L2 of the rotary shaft 10. Due to the structure in which the axis L6 is mounted with an inclination, a large force is not applied to the sensor magnet 50. Further, since the sensor magnet 50 is held in a state where the corner portion 50g of the step portion 50f is in contact with the surface 17b of the step portion 17c of the rotating shaft 10, the sensor magnet 50 is mounted without shaking in the axial direction.

As described above, according to the present embodiment, in addition to the same effects as the effects (5) and (6) of the first embodiment, the following effects are obtained.
(1) By accommodating the retaining washer 16 in the countersunk portion 50j, the axis L6 of the sensor magnet 50 (the axis of the mounting hole 50c) is inclined with respect to the axis L2 of the rotating shaft 10. Therefore, the flat surface portion 17a that directly transmits the rotation of the rotating shaft 10 to the sensor magnet 50 and the flat surface portion 50d of the mounting hole 50c are in line contact and maintained in a line contact state. Therefore, even when the mounting portion 17 of the rotating shaft 10 and the mounting hole 50c of the sensor magnet 50 are fitted with a clearance fit, when the rotating shaft 10 is rotated, the sensor magnet 50 is in contact with the rotating shaft 10. Shaking is prevented. As a result, the rotation position of the rotor 7 detected using the sensor magnet 50 is prevented from being shifted in the rotation direction while the rotor 7 is rotating, and the excitation coil 6 is applied to the excitation coil 6 at an appropriate timing according to the rotation position of the rotor 7. An exciting current can be supplied.

  (2) The retaining washer 16 fixed perpendicularly to the plane portion 17a is accommodated in the countersink portion 50j, and the axis L6 of the sensor magnet 50 (the axis of the mounting hole 50c) with respect to the axis L2 of the rotary shaft 10 ) Is merely inclined, and there is no possibility that a large force is applied to the sensor magnet 50. Therefore, rattling of the sensor magnet 50 with respect to the rotating shaft 10 can be suppressed while preventing damage to the sensor magnet 50 due to the fitting between the mounting portion 17 and the mounting hole 50c.

  (3) The bottom surface 50k is simply configured to form a countersink portion 50j that is inclined in a direction in which the angle with respect to the plane portion 50d changes with respect to the plane S2 perpendicular to the plane portion 50d. The backlash of the sensor magnet 50 with respect to the rotating shaft 10 can be suppressed by bringing 50 m into contact with the flat portion 17a.

In addition, you may change embodiment of this invention as follows.
In the above embodiments, the upper end portion of the boss portion 15b is inclined due to the inclination of the axis lines L1, L3, L5, and L6 of the sensor magnets 15, 30, 40, and 50 with respect to the axis line L2 of the rotating shaft 10. Yes. However, as shown in FIG. 6, the upper end portion of the boss portion 15 b may be adjusted so as to be formed in parallel with the surface S <b> 3 orthogonal to the axis L <b> 2 of the rotating shaft 10. More specifically, FIG. 6 shows the sensor magnet 15 as an example. In the first embodiment, when the sensor magnet 15 is mounted on the mounting portion 17 so that the axis L1 of the sensor magnet 15 is inclined with respect to the axis L2 of the rotating shaft 10, the sensor magnet 15 is applied to the lower end surface of the bearing 12. The upper end surface of the head is inclined and comes into contact. Here, as shown in FIG. 6, the upper end portion of the boss portion 15 b (the upper end portion of the sensor magnet 15) is configured in parallel with the surface S <b> 3 orthogonal to the axis L <b> 2 of the rotating shaft 10. Then, the upper end surface of the sensor magnet 15 can abut on the entire lower surface of the bearing 12, and a more stable structure can be obtained. The sensor magnets 30, 40, and 50 can be configured in a similar manner to have a more stable structure.

  In the first embodiment, the convex portion 15k is formed along the direction perpendicular to the plane portion 15d through the axis L1 of the sensor magnet 15, but is formed without passing through the axis L1 of the sensor magnet 15. May be. For example, like the sensor magnet 60 shown in FIG. 7, it is good also as the convex parts 60b and 60c as an inclination maintenance means formed along the direction orthogonal to the plane part 60a. Moreover, in FIG. 7, although two convex parts 60b and 60c are formed, you may form only one and may form three or more.

  In the first embodiment, the convex portion 15k is formed along the direction passing through the axis of the sensor magnet 15 and orthogonal to the flat portion 15d, but is not limited thereto. The convex portion 15k may be formed like a protrusion on a straight line that passes through the axis of the sensor magnet 15 and is orthogonal to the flat portion 15d on the surface in contact with the retaining washer 16.

  In each of the above embodiments, the lower sides 15m, 30h, 40h, 50m of the flat portions 15d, 30d, 40d, 50d abut against the flat portion 17a, and the sensor magnets 15, 30, 40, The contact portion 15n of the upper opening of the boss portion 15b on the opposite side across the 50 axis lines L1, L3, L5, and L6 is in contact with the rotary shaft 10. However, the present invention is not limited to this, and a configuration as shown in FIG. A sensor magnet 70 shown in FIG. 8 is obtained by changing the shape of the insertion hole 15e of the boss portion 15b and the position of the convex portion 15k in the sensor magnet 15 of the first embodiment. In the center of the sensor magnet 70, an attachment hole 70c having a D-shape in an axial direction passing through the sensor magnet main body 70a and the boss portion 70b is formed. The mounting hole 70 c is formed such that its axis is equal to the axis L 7 of the sensor magnet 70. In the mounting hole 70c, a portion corresponding to the D-shaped straight portion is a flat portion 70d. The sensor magnet 70 is attached to a mounting portion 81 formed at the lower end portion of the rotating shaft 80 with a clearance fit. The mounting portion 81 has a D-shaped cross section, and a portion corresponding to the D-shaped straight portion is a flat surface portion 81a. The mounting portion 81 is formed longer than the axial length of the sensor magnet 70. Further, a stepped portion 81c having a surface 81b orthogonal to the flat surface portion 81a is formed at the base end portion of the mounting portion 81. On the contact surface 70e that comes into contact with the retaining washer 82 of the sensor magnet 70, a convex portion 70f is formed as an inclination maintaining means. The convex portion 70f is formed along a direction passing through the axis L7 of the sensor magnet 70 and orthogonal to the flat surface portion 70d. Furthermore, the convex part 70f is formed in the plane part 70d side in the contact surface 70e. Such a sensor magnet 70 is mounted by fitting the mounting portion 81 into the mounting hole 70c, and is supported in the axial direction by a retaining washer 82. The axis L7 of the sensor magnet 70 (the axis of the mounting hole 70c) is inclined with respect to the axis L8 of the rotating shaft 80 by the convex portion 70f. At this time, the sensor magnet 70 is held by contacting the upper side, that is, the side 70g on the side of the anti-retaining washer 82, of the side in the direction perpendicular to the axial direction of the sensor magnet 70 in the plane portion 70d. ing. At the same time, a part of the lower opening of the mounting hole 70c (abutment portion 70h) is held in contact with the rotary shaft 80 on the opposite side of the axis L7 of the sensor magnet 70. Further, the sensor magnet 70 is held in a state in which the upper end portion thereof is in contact with the surface 81b of the step portion 81c of the rotating shaft 80. Even if comprised in this way, the effect similar to said each embodiment can be acquired.

  In each of the above embodiments, the sensor magnets 15, 30, 40, 50, 70 are configured to include the boss portions 15b, 70b, but may be configured not to include the boss portions 15b, 70b.

  In each of the above embodiments, the sensor magnets 15, 30, 40, 50, 70 are supported in the axial direction by the retaining washers 16, 41, 82, but this is not restrictive. The sensor magnets 15, 30, 40, 50, 70 may be supported in the axial direction by a member other than the toothed washer such as the retaining washers 16, 41, 82.

  In each of the above embodiments, the mounting portions 17 and 81 have a D-shaped cross section, but the present invention is not limited to this. Any mounting part having a non-circular cross section having at least one flat part may be used. In this case, the mounting hole also has a non-circular sectional shape in the axial direction having at least one flat portion corresponding to the mounting portion. Even if comprised in this way, it has the same effect as said each embodiment.

In the above embodiments, the brushless motor 1 is used as a blower motor for a vehicle air conditioner, but may be a brushless motor used for other purposes.
The technical idea that can be grasped from each of the above embodiments will be described below.

  (B) The brushless motor according to any one of claims 2 to 7, wherein the sensor magnet has one side in a direction perpendicular to the axial direction of the sensor magnet in the flat portion of the mounting hole. The sensor magnet is brought into contact with the flat portion of the mounting portion, and the opening of the sensor magnet opposite to the side in the axial direction opposite to the side across the axis of the sensor magnet is brought into contact with the rotating shaft. A brushless motor characterized by being held.

  (B) The brushless motor according to (A) and any one of claims 1 to 8, wherein an end portion of the sensor magnet on the side of the anti-falling member is orthogonal to the axis of the rotating shaft. The brushless motor is adjusted so as to be parallel to the surface to be moved.

Sectional drawing of the brushless motor concerning each embodiment. (A) is sectional drawing (AA sectional drawing in (b)) which shows the mounting part vicinity concerning 1st Embodiment, (b) is a bottom view of a rotor, (c) is a sensor magnet concerning 1st Embodiment. FIG. Sectional drawing which shows the mounting part vicinity concerning 2nd Embodiment. Sectional drawing which shows the mounting part vicinity concerning 3rd Embodiment. Sectional drawing which shows the mounting part vicinity concerning 4th Embodiment. Sectional drawing which shows the sensor magnet by which the upper end part was adjusted in parallel with the surface orthogonal to the axis line of a rotating shaft. The bottom view of the sensor magnet which shows the convex part of another form. Sectional drawing which shows the mounting part vicinity of another form.

Explanation of symbols

  7 ... Rotor 10, 80 ... Rotating shaft, 15, 30, 40, 50, 60, 70 ... Sensor magnet, 15c, 30c, 40c, 50c, 70c ... Mounting hole, 15d, 30d, 40d, 50d, 60a, 70d ... Flat plane part of mounting hole, 15j, 50h, 70e ... Abutting surface, 15k, 60b, 60c, 70f ... Convex part as inclination maintaining means, 16, 82 ... Retaining stopper washer as retaining member, 17, 81 ... Mounting part, 17a, 81a ... flat part of mounting part, 17b, 81b ... surface, 17c, 81c ... step part, 30a ... sensor magnet body as inclination maintaining means and collar part, 41 ... retaining member, and inclination maintaining means Retaining washer as 50j ... Countersink as tilt maintaining means, 50k ... Bottom, L1, L3, L5, L6, L7 ... Sensor magnet axis (axis of mounting hole) ), L2, L8: Axis of rotation axis, L4: A straight line passing through the axis of the sensor magnet and orthogonal to the plane of the mounting hole, S1: A plane perpendicular to the plane of the mounting section, S2: A plane of the mounting hole Vertical plane.

Claims (8)

A rotating shaft provided with a mounting portion provided in the rotor and having a non-circular cross-sectional shape and having at least one plane portion;
A mounting hole having a non-circular shape in the axial direction corresponding to the mounting portion and having at least one flat surface portion is provided, and the rotating shaft is fitted into the mounting hole by a clearance fit to perform the rotation. A sensor magnet attached to the shaft;
A retaining member that is attached to the rotating shaft and contacts the sensor magnet to support the sensor magnet in the axial direction;
A brushless motor that detects a rotational position of the rotor by detecting a magnetic field change of the sensor magnet that rotates with the rotation of the rotor;
The sensor magnet is tilted so that the axis of the mounting hole is tilted with respect to the axis of the rotating shaft, and the plane portion of the mounting hole and the plane portion of the mounting portion of the rotating shaft are in line contact and maintained. A brushless motor comprising a maintenance means. A rotating shaft provided with a mounting portion provided in the rotor and having a D-shaped cross section;
A sensor magnet mounted on the rotating shaft by fitting the mounting portion of the rotating shaft into the mounting hole with a clearance fit;
A retaining member that is attached to the rotating shaft and contacts the sensor magnet to support the sensor magnet in the axial direction;
A brushless motor that detects a rotational position of the rotor by detecting a magnetic field change of the sensor magnet that rotates with the rotation of the rotor;
The sensor magnet is tilted so that the axis of the mounting hole is tilted with respect to the axis of the rotating shaft, and the plane portion of the mounting hole and the plane portion of the mounting portion of the rotating shaft are in line contact and maintained. A brushless motor comprising a maintenance means. The brushless motor according to claim 2,
The tilt maintaining means is a convex portion formed on a contact surface of the sensor magnet that contacts the retaining member, and the sensor magnet is inclined by the convex portion. The brushless motor according to claim 3,
The brushless motor according to claim 1, wherein the convex portion is formed on the opposite side of the sensor magnet with respect to the flat portion of the mounting hole with the axis of the sensor magnet interposed therebetween. The brushless motor according to claim 2,
The sensor magnet includes a flange extending in the radial direction of the rotation shaft,
The brushless motor is characterized in that the inclination maintaining means is a flange portion that is formed with a relatively thin wall thickness along a straight line orthogonal to the flat portion of the mounting hole. The brushless motor according to claim 2,
The inclination maintaining means is the retaining member that is fixed to the mounting portion by being inclined in a direction in which an angle of the mounting portion with respect to the flat portion changes with respect to a plane perpendicular to the flat portion of the mounting portion. Brushless motor characterized by The brushless motor according to claim 2,
The inclination maintaining means is a countersunk portion that is formed on a contact surface that contacts the retaining member in the sensor magnet and accommodates the retaining member,
The brushless motor, wherein a bottom surface of the counterbored portion is formed to be inclined with respect to a plane perpendicular to the flat portion of the mounting hole in a direction in which an angle with respect to the flat portion of the mounting hole changes. The brushless motor according to any one of claims 1 to 7,
A brushless motor, wherein a base end portion of the mounting portion is provided with a step portion having a surface orthogonal to a flat surface portion of the mounting portion, and the sensor magnet is in contact with the surface.

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