JP4480065B2 - Brushless motor - Google Patents

Description

  The present invention relates to a novel brushless motor. More specifically, the present invention relates to a technology that makes the rotor member light and improves the responsiveness.

  There are no brushless motors that rotate in contact other than between the rotating shaft and the bearings. The motor operating environment can be kept clean. The axial length can be shortened and the thickness can be reduced. Control is easy and accurate. Because it has certain advantages, etc., it is used in various situations. Patent Document 1 and Patent Document 2 also show brushless motors.

JP 2002-160581 A

JP 2003-299267 A

  By the way, in the brushless motor described in Patent Document 1 described above, the rotor magnet is fixed to the inner peripheral surface of the rotor case (rotor member). Since a simple coupling structure is not seen, the rotor magnet is fixed to the inner peripheral surface of the rotor case by adhesion, as is generally done conventionally.

  Indeed, the rotor magnet can be fixed to the rotor case by bonding, but there is a problem that the management of the bonding conditions is troublesome and the manufacturing cost is increased. In addition to the problem of manufacturing cost, there is a problem of decrease in adhesive strength due to heat and aging, and there is a problem of lack of reliability. In addition, the rotor case is positioned so as to completely cover the outer peripheral surface of the rotor magnet in order to ensure adhesive strength, which increases the weight of the rotor and, as a result, increases the moment of inertia. There is a problem that the responsiveness of the system becomes dull.

  In the brushless motor described in Patent Document 2, the rotor magnet is fitted in the rotor case, and the engagement protrusion formed on the outer circumferential surface of the rotor magnet is formed on the inner circumferential surface of the rotor case. Thus, the rotor case and the rotor magnet are mechanically coupled to each other. Therefore, although it is free from the various disadvantages related to the above-mentioned adhesion, the rotor case is formed in a size that covers the entire rotor magnet from the outside, thus increasing the weight of the rotor and, as a result, the moment of inertia. There is a problem that the response at start and stop becomes dull.

  Therefore, the present invention increases the reliability by integrating the rotor member and the rotor magnet by mechanical coupling, and reduces the weight of the rotor to reduce the moment of inertia so that a good response can be obtained. The task is to do.

In order to solve the above-described problems, the brushless motor of the present invention has a stator coil fixed at a position surrounding the rotating shaft, a rotor member fixed to the rotating shaft, and a cylindrical shape and is supported by the rotor member. In the brushless motor having a rotor magnet disposed at a position surrounding the stator coil, the rotor member is made of synthetic resin, and the inner peripheral area of the portion overlapping the outer peripheral surface of the rotor magnet in the radial direction is determined by the rotor magnet. An outer peripheral wall that contacts the outer peripheral surface of the rotor magnet, an inner peripheral wall that contacts the inner peripheral surface of the rotor magnet, a gear portion, and the outer peripheral wall and the inner peripheral wall. Engaging protrusions extending in the circumferential direction on the inner peripheral surface of the outer peripheral wall of the rotor member. Formed by engaging the engagement protrusion formed on the upper end portion of the rotor magnet in engagement protrusion of the rotor member, it is obtained by coupling the upper end of the rotor magnet to the rotor member.

Therefore, in the brushless motor of the present invention, the rotor member and the rotor magnet are integrated by mechanical coupling, so that there is no decrease in coupling strength due to heat or aging. Further, since the inner peripheral area of the portion overlapping the rotor magnet in the radial direction of the rotor member is made smaller than the outer peripheral area of the rotor magnet, the weight of the rotor member is reduced. Further, since the upper end portion of the rotor magnet is coupled to the rotor member by engagement, the coupling process of the rotor member and the rotor magnet can be simplified, and the outer peripheral surface of the rotor magnet in the radial direction of the rotor member. It is possible to further reduce the inner peripheral area of the overlapping portion. Further, the rotor magnet engagement protrusions engage with the engagement protrusions of the rotor member, so that the rotor magnet and the rotor member are integrated, and the upper end portion of the rotor magnet is formed by the inner peripheral wall and the outer peripheral wall of the rotor member. Since it can be pressed from inside and outside, it is possible to prevent rattling of the rotor magnet with respect to the rotor member.

The brushless motor of the present invention has a stator coil fixed at a position surrounding the rotating shaft, a rotor member fixed at the rotating shaft, and a cylindrical shape and is supported by the rotor member and disposed at a position surrounding the stator coil. in the brushless motor having a rotor magnet that is, the rotor member while being formed of a synthetic resin, the inner circumferential area of a portion overlapping the outer circumferential surface of the rotor magnet is smaller than the outer circumference area of the rotor magnet in the radial direction, the An outer peripheral wall that contacts the outer peripheral surface of the rotor magnet, an inner peripheral wall that contacts the inner peripheral surface of the rotor magnet, and a gear portion are integrally formed, and the outer peripheral wall and the inner peripheral wall are part of the rotor member. Alternatively, an engagement protrusion is formed on the inner peripheral surface of the outer peripheral wall of the rotor member and formed in the circumferential direction. By Tsu preparative upper engaging ridges formed on part of the is engaged with the engaging protrusion of the rotor member, an upper end portion of the rotor magnet is characterized by being coupled to the rotor member.

Therefore, in the brushless motor of the present invention, the rotor member and the rotor magnet are integrated by mechanical coupling, so that there is no decrease in coupling strength due to heat or aging. Therefore, there is no possibility that the coupling force between the rotor member and the rotor magnet is reduced due to the influence of heat or aging, and the reliability is high. Further, since the upper end portion of the rotor magnet is coupled to the rotor member by engagement, the coupling process of the rotor member and the rotor magnet can be simplified, and the outer peripheral surface of the rotor magnet in the radial direction of the rotor member. It is possible to further reduce the inner peripheral area of the overlapping portion. Further, the rotor magnet engagement protrusions engage with the engagement protrusions of the rotor member, so that the rotor magnet and the rotor member are integrated, and the upper end portion of the rotor magnet is formed by the inner peripheral wall and the outer peripheral wall of the rotor member. Since it can be pressed from inside and outside, it is possible to prevent rattling of the rotor magnet with respect to the rotor member.

  Further, there are no troublesome handling items such as management of bonding conditions at the time of manufacturing, and the manufacturing cost can be reduced.

  Further, since the inner peripheral area of the portion overlapping the outer peripheral surface of the rotor magnet in the radial direction of the rotor member is made smaller than the outer peripheral area of the rotor magnet, the weight of the rotor member is reduced. Therefore, the moment of inertia can be reduced, the response at the time of starting and stopping can be improved, and the control performance is improved.

In the invention described in claim 2 and claim 3, the rotor member is formed with a plurality of confirmation holes opened in the vertical direction at intervals in the circumferential direction, and the upper end portion of the rotor magnet is formed in the confirmation direction. Since the rotor member is engaged below the confirmation hole at the position where the hole is formed, the coupling state between the rotor member and the rotor magnet can be confirmed through the confirmation hole. Therefore, it is possible to prevent the unreliable connection from being left.

In the invention described in claim 4 , an engagement protrusion that protrudes in the radial direction is formed on the inner peripheral surface of the rotor member or the outer periphery of the rotor magnet, and the outer periphery of the rotor magnet or the above Since the engagement recess that engages with the engagement protrusion is formed on the inner peripheral surface of the rotor member, relative rotation between the rotor member and the rotor magnet can be prevented, and the rotor member Positioning when connecting with the rotor magnet.

  The best mode for carrying out the brushless motor of the present invention will be described below with reference to the accompanying drawings.

  2 to 6 show a first embodiment of the brushless motor of the present invention.

  The brushless motor 1 includes a stator portion 10 and a rotor 20 that is rotatably supported with respect to the stator portion 10.

  The stator portion 10 includes a bearing portion 11 and a stator coil 12 fixedly provided around the bearing portion 11.

  The bearing portion 11 includes a cylindrical portion 11a formed of an insulating material and a bearing metal 11b fixed in a press-fit manner in the cylindrical portion 11a. When the brushless motor 1 is configured as a single product, the cylindrical portion 11a is formed by protruding integrally from a substantially flat base plate. However, when the brushless motor 1 is integrally incorporated in a device using the brushless motor 1, In many cases, it is integrally formed in the housing of the apparatus, and in the first embodiment, a case where it is integrally incorporated in an actuator for changing the irradiation direction of an automotive headlamp described later is shown. It is integrally formed from the bottom plate 13 of the actuator housing.

  The stator coil 12 is formed by winding a coil winding 12b around a core 12a, and the core 12a is fixed in a state where the core 12a is externally fitted to the cylindrical portion 11a.

  Terminal pins 12c, 12c,... (Only one is shown in FIG. 1) for supplying power to the coil winding 12b are press-fitted into a core base 12d that is formed of an insulating material and supports the core 12a. Is initially positioned higher than a predetermined position, and an end portion 12b 'of the coil winding 12b is entangled with an upper end portion of the terminal pin 12c by a winding machine for winding the coil winding 12b. After soldering the end 12b 'to the upper end of the terminal pin 12c, the terminal pin 12c is pushed into the core base 12d to a predetermined position. Thus, the end 12b 'of the coil winding 12b can be curled to the terminal pin 12c by the winding machine, and the end of the coil winding 12b by pushing the terminal pin 12c to a predetermined position from the position where the curling is performed. Since the portion 12b 'approaches the coil winding 12b and can sag, it is possible to prevent disconnection due to excessive tension. Further, the brushless motor 1 can be configured in a small size.

  The rotor 20 is composed of a rotor member 30 formed of an insulating material, for example, a synthetic resin such as Duracon (trade name of copolymer plastics of copolymer polyacetal), and a rotor magnet mechanically coupled to the rotor member 30. 40, and is rotatably supported by the stator unit 10 via the rotation shaft 50.

  The rotor member 30 includes a substantially circular disc portion 31, a cylindrical portion 32 provided so as to penetrate the center of the disc portion 31, and a peripheral wall portion 33 suspended downward from the outer edge of the disc portion 31. Are integrally formed.

  A through hole 32 a is formed through the center of the cylindrical portion 32, and the upper end portion of the rotary shaft 50 is press-fitted into the through hole 32 a, whereby the rotor member 30 is inserted into the upper end portion of the rotary shaft 50. Fixed. A portion 32b of the cylindrical portion 32 protruding upward from the upper surface of the disc portion 31 is formed with gear teeth on the outer peripheral surface to form a pinion gear.

  The part from the lower side to the lower side from the upper end of the peripheral wall 33 is doubled inside and outside. That is, a narrow flange-like portion 34 is formed projecting outward from a slightly lower position from the upper end of the peripheral wall portion 33, and the outer peripheral wall 35 is projected downward from the outer edge of the flange-like portion 34. The A portion 33a of the peripheral wall portion 33 located below the flange-shaped portion 34 serves as an inner peripheral wall, and a groove 36 opened downward is formed between the inner peripheral wall 33a and the outer peripheral wall 35. The flange-shaped portion 34 is formed with circumferentially long confirmation holes 37, 37, 37 at intervals in the circumferential direction, and is formed on the inner circumferential surface of the outer peripheral wall 35 at a position below the confirmation holes 37, 37, 37. Engagement protrusions 38, 38, 38 extending in the circumferential direction are formed. The lower surfaces of the engaging protrusions 38, 38, 38 are inclined surfaces 38a, 38a, 38a that are displaced outward as they go downward. Engagement protrusions 39, 39, 39 projecting inward are formed at positions corresponding to the positions between the check holes 37, 37 on the inner peripheral surface 35 a of the outer peripheral wall 35.

  The rotor magnet 40 has a substantially cylindrical shape, and is S and N alternately magnetized in, for example, eight divisions in the circumferential direction. An engagement protrusion 41 extending in the circumferential direction is formed on the outer peripheral surface of the upper end portion of the rotor magnet 40. And the said engagement protrusion 41 is removed at intervals in the circumferential direction, and the engagement recessed parts 42, 42, 42 are formed there.

  The rotor member 30 and the rotor magnet 40 are coupled as follows.

  That is, the upper end portion of the rotor magnet 40 is inserted into the groove 36 between the inner peripheral wall 33a and the outer peripheral wall 35 of the rotor member 30 from below. At this time, it is necessary to align the engaging recesses 42, 42, 42 of the rotor magnet 40 with the engaging protrusions 39, 39, 39 of the rotor member 30. Thereby, the upper end portion of the rotor magnet 40 is fitted into the groove 36 while the engagement recesses 42, 42, 42 of the rotor magnet 40 engage with the engagement protrusions 39, 39, 39 of the rotor member 30. go. When the upper end of the rotor magnet 40 comes to a position where the upper end of the rotor magnet 40 comes into contact with the flange-like portion 34 of the rotor member 30, the engagement protrusions 41, 41, 41 of the rotor magnet 40 are engaged with the engagement protrusions 38, 38, Engage with the top surface of 38. Thereby, the rotor magnet 40 is integrated with the rotor member 30, and the engagement recesses 42, 42, 42 of the rotor magnet 40 are engaged with the engagement protrusions 39, 39, 39 of the rotor member 30, Mutual rotation between the rotor member 30 and the rotor magnet 40 is prevented. Since the upper end portion of the rotor magnet 40 is pressed from the inside and outside by the inner peripheral wall 33 a and the outer peripheral wall 35 of the rotor member 30, the rotor magnet 40 does not rattle against the rotor member 30.

  The rotor 20 is positioned so as to surround the stator coil 12 by inserting the rotary shaft 50 fixed to the rotor 20 assembled as described above into the bearing metal 11b and supporting it, and the rotor 20 is thus positioned in the stator portion 10. Is supported rotatably.

  A circuit board 14 is supported on the lower surface of the bottom plate 13 of the housing, and a Hall element 15 mounted on the circuit board 14 is provided at the lower end surface of the rotor magnet 40 through a hole 13a formed in the bottom plate 13 of the housing. It faces in the proximity state. The lower ends of the terminal pins 12c, 12c,... Are inserted through holes 13b, 13b,... (Only one is shown in FIG. 1), 14a, 14a,. ... (only one is shown in FIG. 1) is inserted and soldered to terminal portions 14b, 14b formed on the lower surface of the circuit board 14 (only one is shown in FIG. 1).

  In the brushless motor 1 described above, since the rotor member 30 and the rotor magnet 40 are integrated by mechanical coupling, there is no reduction in coupling strength due to heat or aging. Therefore, there is no possibility that the coupling force between the rotor member 30 and the rotor magnet 40 is reduced due to the influence of heat or aging, and the reliability is high.

  Further, there are no troublesome handling items such as management of bonding conditions at the time of manufacturing, and the manufacturing cost can be reduced.

  Further, since the area (inner peripheral area) of the inner peripheral surface 35a of the outer peripheral wall 35 that overlaps the outer peripheral surface 40a of the rotor magnet 40 in the radial direction of the rotor member 30 is smaller than the outer peripheral area of the rotor magnet 40, the rotor member The weight of 30 becomes lighter. Therefore, the moment of inertia of the rotor 20 can be reduced, the responsiveness at the time of starting and stopping can be improved, and the control performance is improved.

  In the brushless motor 1, since the upper end portion of the rotor magnet 40 is coupled to the rotor member 30 by engagement, the coupling process of the rotor member 30 and the rotor magnet 40 can be simplified. It is possible to further reduce the inner peripheral area of the outer peripheral wall 35 that is a portion overlapping the outer peripheral surface 40a of the rotor magnet 40 in the radial direction of the rotor member 30.

  The rotor member 30 is formed with a plurality of confirmation holes 37, 37, 37 that are opened in the vertical direction at intervals in the circumferential direction, and the upper end portion of the rotor magnet 40 has the confirmation holes 37, 37, 37. Since it is engaged with the rotor member 30 below the confirmation holes 37, 37, 37 at the formed position, when the rotor member 30 and the rotor magnet 40 are coupled, the coupling state of the two is confirmed by the confirmation holes 37, 37, 37 can be confirmed. Therefore, it is possible to prevent the unreliable connection from being left.

  Further, an outer peripheral wall 35 that contacts the outer peripheral surface 40a of the rotor magnet 40 and an inner peripheral wall 33a that contacts the inner peripheral surface of the rotor magnet 40 are formed over the entire circumference of the rotor member 30. Since the confirmation holes 37, 37, 37 are formed between the outer peripheral wall 35 and the inner peripheral wall 33a, the rotor magnet 40 can be pressed from the inside and outside by the outer peripheral wall 35 and the inner peripheral wall 33a of the rotor member 30, The rattling of the rotor magnet 40 can be prevented.

  Furthermore, engagement protrusions 39, 39, 39 that protrude in the radial direction are formed on the inner peripheral surface 35 a of the outer peripheral wall 35 of the rotor member 30, and the engagement protrusions are formed on the outer peripheral portion of the rotor magnet 40. Since the engaging recesses 42, 42, 42 that engage with the portions 39, 39, 39 are formed, relative rotation between the rotor member 30 and the rotor magnet 40 can be prevented, and the rotor member 30. Is positioned when the rotor magnet 40 is coupled. Note that an engagement recess may be formed in the rotor member 30 and an engagement protrusion may be formed in the rotor magnet 40.

  5 and 6 show specific examples of use of the brushless motor 1 described above. Here, the brushless motor 1 is used as a drive source of an actuator that tilts a lamp unit that irradiates a beam in a horizontal direction in an automotive headlamp to change the irradiation direction of the beam in the horizontal direction.

  The automotive headlamp 100 includes a lamp body 110 having a recess opening forward, and the front opening of the lamp body 110 is covered with a transparent cover 120 to form a lamp chamber 130. A bracket 140 that is tiltably supported with respect to the lamp body 110 is disposed in the lamp chamber 130, and the lamp unit 150 is supported by the bracket 140 so as to be tiltable in the horizontal direction.

  The lamp unit 150 limits the upper edge of the reflector 151, the light source bulb 152 supported by the reflector 151, the light projection lens 153 provided so as to cover the front of the reflector 151, and the pattern (light distribution pattern) of the irradiation light. A shade 154 is provided. The reflector 151 includes a reflecting surface 151 a having a light collecting property, and the light projecting lens 153 having a convex lens shape is supported at the tip of a substantially cylindrical mounting frame 155 fixed to the front end of the reflector 151. .

  The light emitted from the light source bulb 152 and reflected by the reflecting surface 151a of the reflector 151 is collected near the upper edge 154a of the shade 154. Further, the focal point of the light projecting lens 153 is located in the vicinity of the upper edge 154a of the shade 154. Therefore, a light beam whose front edge is limited by the upper edge 154 a of the shade 154 is irradiated forward by the light projecting lens 153.

  A fulcrum shaft 156 protrudes upward from the upper surface of the rear end portion of the mounting frame 155, and a connecting boss 157 protrudes downward from the lower surface of the rear end portion. The connection boss 157 has a connection recess 157a that opens downward. In addition, the center of the connection recessed part 157a and the center of the said fulcrum shaft 156 are coaxially located.

  In the lamp unit 150, the fulcrum shaft 156 is rotatably supported by a shaft support portion 142 provided at the front end portion of the support piece 141 on the upper side of the bracket 140, and the connecting boss 157 is connected to the support piece 143 on the lower side of the bracket 140. The insertion hole 144 provided in the front end is inserted downward. The rear end portion of the lamp unit 150 protrudes rearward from a large opening 145 provided in the bracket 140.

  The lamp unit 150 is tilted in the horizontal direction by an actuator 160 fixed to the lower surface of the support piece 143 below the bracket 140.

  The actuator 160 includes a drive shaft 162 that protrudes upward from the upper surface of the housing 161, and the drive shaft 162 is coupled to the coupling recess 157a of the lamp unit 150 in an internally fitted manner. Engaging protrusions 162a, 162a,... Extending in the axial direction protrude from the outer peripheral surface of the drive shaft 162, and the drive shaft 162 is fitted in a connecting recess 157a formed on the lower surface of the lamp unit 150. When the engagement protrusions 162a, 162a,... Engage with an engagement groove (not shown) formed on the inner peripheral surface of the connection recess 157a, the rotation between the drive shaft 162 and the connection recess 157a. Directional slippage is prevented.

  The brushless motor 1 is used as a drive source for rotating the drive shaft 162.

  The housing 161 of the actuator 160 includes a mid case 161a, an upper cover 161b that covers the upper surface of the mid case 161a, and a lower cover 161c that covers the lower surface of the mid case 161a. A partition wall 161d (corresponding to the bottom plate 13 of the housing) that covers the bottom is formed in the mid case 161a, thereby forming a large space 161e that opens upward. The lower surface of the mid case 161a is covered with a lower cover 161c, and the circuit board 14 is disposed in a space between the mid case 161a and the lower cover 161c.

  A sector gear 162b is integrally formed at the lower end of the drive shaft 162, and is rotatably supported by a support shaft 161f raised from the partition wall 161d of the midcase 161a.

  A cylindrical portion 11a of the bearing portion 11 of the brushless motor 1 is integrally projected from the partition wall 161d of the midcase 161a. A stator coil 12 is disposed so as to surround the cylindrical portion 11a. Is rotatably supported by the bearing metal 11b disposed in the cylindrical portion 11a via the rotation shaft 50.

  Three intermediate gears 163, 164, 165 are interposed between the pinion gear 32 b of the brushless motor 1 and the sector gear 162 b of the drive shaft 162. Each of the intermediate gears 163, 164, 165 is not shown in the figure because the large gears 163a, 164a, 165a and the small gear 165b (the small gears of the intermediate gears 163, 164 are located below the large gears 163a, 164a) ) Are integrally formed, and are rotatably supported by support shafts 163c, 164c, and 165c provided upright on the partition wall 161d. The large gear 163a of the intermediate gear 163 is engaged with the pinion gear 32b of the brushless motor 1, the small gear of the intermediate gear 163 is engaged with the large gear 164a of the intermediate gear 164, and the small gear of the intermediate gear 164 is large of the intermediate gear 165. The small gear 165b of the intermediate gear 165 is meshed with the sector gear 162b of the drive shaft 162. Accordingly, when the brushless motor 1 is driven, the drive shaft 162 is rotated via the intermediate gears 163, 164, 165.

  7 to 10 show a second embodiment of the brushless motor of the present invention. In the second embodiment, since the stator portion is the same as that in the first embodiment, only the rotor is shown in FIGS.

  The rotor 60 is formed by mechanically coupling a rotor member 70 and a rotor magnet 80.

  The rotor member 70 is made of an insulating material, for example, a synthetic resin material such as Duracon (trade name). The rotor member 70 has a disk portion 71, a cylindrical portion 72 provided so as to penetrate the center of the disk portion 71, and the above A side surface portion 73 protruding downward from the outer edge of the disc portion 71 is integrally formed.

  The cylindrical portion 72 is formed with a through hole 72a penetrating the center up and down, and the upper end portion of the rotary shaft 90 is fixed in a press-fit manner to the through hole 72a. Further, gear teeth are formed on the outer peripheral surface of a portion of the cylindrical portion 72 protruding upward from the disc portion 71 to form a pinion gear 72b.

  The side surface portion 73 extends downward from the outer edge of the disc portion 71 and then protrudes outward and further extends downward, forming a crank shape with a cross-sectional shape, and facing downward from the lower surface of the disc portion 71 to a position slightly below. A recessed surface 73a is formed. Further, from the disk portion 71 to the side surface portion 73, grooves that form a U-shape when viewed from the outer edge side down are formed at three locations at intervals in the circumferential direction, and are surrounded by the U-shaped grooves. Elastic contact pieces 74, 74, 74 having elasticity are formed in the corresponding portions.

  Further, the engagement pieces 75, 75,... Protrude downward from four locations that are spaced at substantially equal intervals in the circumferential direction at the lower end of the side surface portion 73, and the engagement pieces 75, 75,. Engaging claws 75a, 75a,... Project from the lower end of the. The lower surfaces of the engaging claws 75a, 75a,... Are inclined surfaces 75b, 75b,.

  The rotor magnet 80 has a substantially cylindrical shape, and is divided into eight parts at equal intervals in the circumferential direction, for example, and S and N are alternately magnetized. The outer peripheral surface is formed with, for example, eight plane portions 82, 82,... At equal intervals in the circumferential direction, leaving the intermediate portion 81, and immediately below the lower plane portions 82, 82,. .. Are formed on the upper surface by the lower surface of the intermediate portion 81.

  Therefore, when the upper end portion of the rotor magnet 80 is inserted inside the side surface portion 73 of the rotor member 70, the upper end of the intermediate portion 81 is inclined surfaces 75b, 75b of the engaging claws 75a, 75a,.・ Press and bend the engaging pieces 75, 75,. When the upper end of the rotor magnet 80 is inserted to a position where the upper end of the rotor magnet 80 comes into contact with the surface 73a facing the lower side of the side surface portion 73, the engaging claws 75a, 75a,. Are engaged with each other, whereby the rotor member 70 and the rotor magnet 80 are coupled by engagement to form the rotor 60. The tip portions of the elastic contact pieces 74, 74,... Of the rotor member 70 are located slightly below the surface 73a facing downward, and the upper surface of the rotor magnet 80 faces the downward surface 73a. In the state of contact with each other, the tip portions of the elastic contact pieces 74, 74,... Elastically press the upper end of the rotor magnet 80 downward, thereby preventing the rotor magnet 80 from rattling against the rotor member 70. Is done.

  In the rotor 20 of the brushless motor according to the second embodiment described above, since the rotor member 70 and the rotor magnet 80 are integrated by mechanical coupling, there is no decrease in coupling strength due to heat or aging. For this reason, there is no possibility that the coupling force between the rotor member 70 and the rotor magnet 80 is lowered due to the influence of heat or aging, and the reliability becomes high.

  Further, there are no troublesome handling items such as management of bonding conditions at the time of manufacturing, and the manufacturing cost can be reduced.

  Further, the area (inner peripheral area) of the inner peripheral surface 73b ′ of the outer peripheral wall 73b located outside the rotor magnet 80 in the side surface portion 73 that overlaps the outer peripheral surface 80a of the rotor magnet 80 in the radial direction of the rotor member 70. And the area (inner peripheral area) of the inner peripheral surfaces 75c, 75c, ... of the engaging pieces 75, 75, ... is made smaller than the outer peripheral area of the rotor magnet 80, so the weight of the rotor member 70 is reduced. Therefore, the moment of inertia of the rotor 60 can be reduced, the responsiveness at the time of starting and stopping can be improved, and the control performance is improved.

  Further, since the rotor magnet 80 is coupled to the rotor member 70 by engagement, the coupling process of the rotor member 70 and the rotor magnet 80 can be simplified, and the rotor magnet 80 in the radial direction of the rotor member 70 can be achieved. It is possible to further reduce the inner peripheral area of the outer peripheral wall 73b and the engagement pieces 75, 75,.

  Further, of the outer peripheral surface 80a of the rotor magnet 80, the engaging claws 75a formed on the engaging pieces 75, 75,... Of the rotor member 70 at the portions where the flat portions 82, 82,. , 75a,... Engage with the engaging surfaces 83, 83,... Of the rotor magnet 80, so that the engaging pieces 75, 75,. Accordingly, the rotation is stopped, and relative rotation between the rotor member 70 and the rotor magnet 80 can be prevented. The upper plane portions 82, 82,... Formed on the rotor magnet 80 are inserted into the side portions 73 of the rotor member 70 when the rotor magnet 80 is inserted into the plane portions 82, 82,. The positioning is achieved by bringing the engaging pieces 75, 75,.

  It should be noted that the shapes and structures of the respective parts shown in the above-described embodiments are merely examples of implementations in carrying out the present invention, and the technical scope of the present invention is limited by these. It should not be interpreted in a general way.

  According to the present invention, a brushless motor having a very small moment of inertia and high reliability can be provided, which is suitable for application to various control devices.

2 to 6 show a first embodiment of the brushless motor of the present invention, and this figure is a longitudinal sectional view. It is a disassembled perspective view of a rotor. It is a top view of a rotor. It is a bottom view of a rotor member. FIG. 6 shows an example of use of the brushless motor according to the present invention, and FIG. 6 is a longitudinal sectional view of an automotive headlamp. It is a disassembled perspective view of an actuator. 8 to 10 show a rotor in a second embodiment of the brushless motor of the present invention, and this figure is a side view. It is a top view. It is a bottom view. It is a longitudinal cross-sectional view.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Brushless motor, 12 ... Stator coil, 30 ... Rotor member, 33a ... Inner peripheral wall, 35 ... Outer peripheral wall (part which overlaps with the outer peripheral surface of a rotor magnet in radial direction), 37 ... Confirmation hole, 39 ... Engagement protrusion, DESCRIPTION OF SYMBOLS 40 ... Rotor magnet, 42 ... Engagement recessed part, 50 ... Rotating shaft, 70 ... Rotor member, 73b ... Outer peripheral wall (part overlapped with outer peripheral surface of rotor magnet in radial direction), 75 ... Engagement piece (rotor magnet in radial direction) Part overlapping with the outer peripheral surface), 90...

Claims (4)

A stator coil fixed at a position surrounding the rotating shaft, a rotor member fixed at the rotating shaft, and a rotor magnet that is cylindrical and supported by the rotor member and disposed at a position surrounding the stator coil. Brushless motor
The rotor member is formed of synthetic resin, and the inner peripheral area of the portion overlapping the outer peripheral surface of the rotor magnet in the radial direction is smaller than the outer peripheral area of the rotor magnet,
An outer peripheral wall that comes into contact with the outer peripheral surface of the rotor magnet, an inner peripheral wall that comes into contact with the inner peripheral surface of the rotor magnet, and a gear portion are integrally formed. Formed over the entire circumference or
An engagement protrusion extending in the circumferential direction is formed on the inner peripheral surface of the outer peripheral wall of the rotor member, and an engagement protrusion formed on the upper end portion of the rotor magnet is engaged with the engagement protrusion of the rotor member. Thus , the brushless motor, wherein the upper end portion of the rotor magnet is coupled to the rotor member . The rotor member is formed with a plurality of confirmation holes opened in the vertical direction at intervals in the circumferential direction, and the upper end portion of the rotor magnet is engaged with the rotor member below the confirmation hole at the position where the confirmation hole is formed. The brushless motor according to claim 1, wherein the brushless motor is combined. The brushless motor according to claim 1, wherein the confirmation hole is formed between the outer peripheral wall and the inner peripheral wall. Engaging protrusions that project in the radial direction are formed on the inner peripheral surface of the rotor member or the outer peripheral portion of the rotor magnet, and the engaging protrusions are formed on the outer peripheral portion of the rotor magnet or the inner peripheral surface of the rotor member. The brushless motor according to claim 1, wherein an engagement recess that engages with the portion is formed.

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