JP2010045890A - Geared outer-rotor brushless motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a geared outer-rotor brushless motor which can be made compact with simple configuration. <P>SOLUTION: When a rotor shaft 101, a gear shaft 201 and a shaft 301 are arranged substantially in parallel, a worm gear which is required in a conventional inner rotor type motor is eliminated and rotation of an outer rotor 104 can be transmitted to a slowdown section 20 and a rotation output section 30 with simple configuration. Furthermore, the rotation output section 30 is arranged in a case 2 so that one end of the shaft 301 is pivotally supported by a sleeve 29 provided in the case 2, and the distance L between the centers of rotation of the shaft 301 and a driven gear 202 becomes shorter than the radius R of the driven gear 202. Consequently, the case 2 can be made compact by arranging the slowdown section 20 and the rotation output section 30 more closely each other, and thereby a brushless motor 1 can be made compact. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an outer rotor type brushless motor with a gear mechanism in which a gear mechanism is integrated.

  Conventionally, there is known a motor with a gear mechanism in which a motor unit and a gear mechanism such as a speed reduction mechanism are integrally provided in a case. In the motor with a gear mechanism described in Patent Document 1, an inner rotor type motor as a motor unit and a plurality of reduction gears as a gear mechanism are provided in a case, and the rotation shaft of the inner rotor type motor and the rotation shaft of the reduction gear are provided. Are arranged so as to be substantially orthogonal to each other. The rotation speed of the inner rotor type motor is reduced at a predetermined rate by transmitting the rotation of the inner rotor type motor to each reduction gear via a worm gear attached to the rotation shaft of the inner rotor type motor. Has been.

Japanese Patent Laying-Open No. 2005-54950 ([0026] to [0032], FIGS. 1 to 3 etc.)

  By the way, because of the structure, the inner rotor type motor has a small moment of inertia, so that the motor tends to increase in size in the direction of the rotation axis in order to obtain a sufficient driving torque, and the size of the motor in the direction of the rotation axis increases. There was a problem of increasing the size. Therefore, in the motor with a gear mechanism described above, the thickness of the case can be prevented from increasing by arranging the rotation shaft of the inner rotor type motor and the rotation shaft of the reduction gear in the case so as to be substantially orthogonal to each other. The motor with gear mechanism is made compact.

  However, with such a configuration, since the direction of the rotation axis of the inner rotor type motor is different from the direction of the rotation axis of the reduction gear, it is necessary to transmit the rotation of the inner rotor type motor to the reduction gear via the worm gear. There is a problem that the number of parts increases as the worm gear is required. Further, both ends of the rotation shaft of each reduction gear are rotatably supported by the upper and lower surfaces facing each other. Therefore, in order to prevent one reduction gear and the rotation shafts of the other reduction gears from contacting each other, place each reduction gear in the case so that the distance between the rotation shafts of each reduction gear is longer than the gear radius. Since it was necessary to arrange it, it was an obstacle to making the case compact, and an improvement was demanded.

  The present invention has been made in view of the above problems, and an object thereof is to provide an outer rotor type brushless motor with a gear mechanism that can be made compact with a simple configuration.

  In order to solve the above-described problems, an outer rotor type brushless motor with a gear mechanism according to the present invention is disposed in a case, with the case and both ends rotatably supported on one surface and the other surface of the case facing each other. A motor portion having a rotor shaft that is formed, an outer rotor that rotates integrally with the rotor shaft, and a circuit board for driving control of the motor portion that is fixedly disposed on the one surface side in the case. Both ends of the case are rotatably supported on the one surface and the other surface of the case and are fitted in the outer periphery of the rotor shaft near the other surface, and a gear rotation shaft disposed in the case in parallel with the rotor shaft. A rotor gear, a driven gear that has a larger diameter than the outer diameter of the outer rotor, is fitted on the outer periphery of the gear rotation shaft, and meshes with the rotor gear; A speed reduction portion having a transmission gear attached to a gear rotation shaft and rotating integrally with the driven gear; and disposed in the case in parallel with the rotor shaft and the gear rotation shaft, with one end on the one surface A rotation output portion having a shaft portion rotatably supported and an output gear provided on the other end side of the shaft portion and meshing with the transmission gear to rotate integrally with the shaft portion, The rotation output unit is arranged in the case so that a distance between a rotation center of the rotation output unit and a rotation center of the driven gear is shorter than a radius of the driven gear. 1).

  Further, at least the one surface of the case is made of metal, and the circuit board is disposed in close contact with the one surface of the case (Claim 2).

  Further, the circuit board may be formed to have substantially the same size as the one surface of the case, and may be disposed in close contact over substantially the entire surface of the one surface.

  Further, the apparatus further includes a preventing means for preventing the lubricant from scattering from the transmission gear and the output gear in the case to the circuit board.

  In addition, the rotor shaft, the gear rotation shaft, and the shaft portion are arranged substantially in a straight line in the case (Claim 5).

  In addition, a connector is disposed at a position near the gear rotation axis on the circuit board, and the connector is exposed to the outside of the case so that an external device and the drive control circuit board can be electrically connected. (Claim 6).

  According to the first aspect of the present invention, the motor portion is configured by an outer rotor type having a larger moment of inertia than the inner rotor type, and even if the rotor shaft is configured shorter than the inner rotor type, Since the desired driving torque can be obtained, the axial thickness of the outer rotor type brushless motor with gear mechanism is increased even if the rotor shaft, the gear rotation shaft, and the shaft portion are arranged substantially in parallel. At the same time, the size in the direction of the rotation axis does not increase as in the case of adopting the conventional inner rotor type. In addition, by arranging the rotor shaft of the motor unit, the gear rotation shaft of the speed reduction unit, and the shaft unit of the rotation output unit almost in parallel, the rotation of the outer rotor can be performed with a simple configuration without the need for a worm gear, which was necessary in the past. Can be transmitted to the speed reduction unit and the rotation output unit. Further, the rotation output portion is rotatably supported at one end of the shaft portion on one surface of the case, and the distance between the rotation center of the shaft portion and the rotation center of the driven gear is shorter than the radius of the driven gear. It arrange | positions in a case so that it may become. Therefore, the case can be made compact by arranging the speed reduction portion and the rotation output portion closer to each other, and the outer rotor type brushless motor with gear mechanism can be made compact.

  According to the second aspect of the present invention, since the circuit board is disposed in close contact with one side of the case made of metal, the electronic component for driving the motor unit provided on the circuit board generates heat. However, the generated heat can be efficiently dissipated through one side of the case made of metal.

  According to the third aspect of the present invention, the circuit board is formed in substantially the same size as the one surface of the case, and is arranged in close contact over the entire surface of the one surface. As a result, the heat generated when the electronic component generates heat can be dissipated more efficiently to the outside of the case. Further, since the circuit board is formed to be approximately the same size as the one surface of the case, the area of the circuit board is increased, and all the electronic components for driving the motor unit can be easily provided on the circuit board.

  According to the fourth aspect of the invention, the lubricant can be prevented from scattering from the transmission gear and the output gear in the case to the circuit board by the prevention means for preventing the lubricant from scattering.

  According to the fifth aspect of the present invention, the rotor shaft, the gear rotation shaft, and the shaft portion are arranged substantially in a straight line in the case. A brushless motor can be provided.

  According to the sixth aspect of the present invention, the connector is provided outside the case at a position near the gear rotation shaft on the circuit board so that the external device and the drive control circuit board can be electrically connected. Therefore, it is possible to obtain a configuration in which an external device and an outer rotor type brushless motor with a gear mechanism can be easily electrically connected.

  An embodiment of an outer rotor type brushless motor 1 with a gear mechanism of the present invention will be described with reference to FIGS. FIG. 1 is a cut front view of an outer rotor type brushless motor 1 with a gear mechanism, and is a cross-sectional view taken along line AA in FIG. 2 is an external view of the outer rotor type brushless motor 1 with a gear mechanism in FIG. 1, wherein (a) is a rear view, (b) is a plan view, (c) is a front view, and (d) is a bottom view. . 3A and 3B are views showing the case main body 21, wherein FIG. 3A is a plan view, FIG. 3B is a cut front view, and is a cross-sectional view taken along line B-B in FIG. 4A and 4B are views showing the lid 22, wherein FIG. 4A is a plan view, FIG. 4B is a cut front view, and is a cross-sectional view taken along line CC of FIG. 4A, and FIG. FIG. 5 is a bottom view of the drive control circuit board 3. 6A and 6B are views showing the resin plate 4, in which FIG. 6A is a bottom view, and FIG. 6B is a cross-sectional view taken along line D-D in FIG.

  As shown in FIG. 1, an outer rotor type brushless motor with a gear mechanism (hereinafter simply referred to as “brushless motor”) 1 of the present invention includes a motor unit 10 and a drive control circuit board (hereinafter simply referred to as “circuit board”). 3), a speed reduction unit 20, and a rotation output unit 30 are integrally provided in the case 2. As shown in FIG. 2A, a connector 31 is disposed in the vicinity of the gear rotation shaft 201 of the speed reduction unit 20 on the circuit board 3, and the connector 31 electrically connects the external device and the circuit board 3 to each other. The case 2 is provided so as to be exposed to the outside. Further, the rotation output unit 30 is disposed in the case 2 so that the shaft portion 301 of the rotation output unit 30 is exposed to the outside of the case 2 so that the rotation of the motor unit 10 can be output to an external device. Hereinafter, the brushless motor 1 will be described in detail.

  As shown in FIGS. 3 and 4, the case 2 includes a substantially rectangular parallelepiped case main body 21 having an opening 23 on one surface, and a metal lid 22 formed so as to close the opening 23 of the case main body 21. It is configured. A bottom surface 24 (corresponding to the “other surface” of the present invention) 24 of the case body 21 includes a bearing 24 a that can rotatably support the other end of the rotor shaft 101 of the motor unit 10, and a gear rotation shaft 201 of the speed reduction unit 20. A bearing 24b that can rotatably support the other end is formed. A side groove 21a is formed on the inner side wall of the case body 21 so that a resin plate 4 described later can be fitted and fixed.

  The lid 22 has a fitting hole 25 into which a bottomed cylindrical bearing bush 28 that rotatably supports one end of the rotor shaft 101 is fitted, and a support that can rotatably support one end of the gear rotation shaft 201. A hole 26 and a fitting hole 27 into which a sleeve 29 that rotatably supports one end of the shaft portion 301 is formed are formed. As shown in FIG. 1, a bearing bush 28 is fitted in the fitting hole 25, and one end of the rotor shaft 101 is rotatably supported by a recess 28 a formed on the bottom surface of the bearing bush 28. It is configured. A sleeve 102 that rotatably supports the rotor shaft 101 is disposed inside the bearing bush 28. Thereby, both ends of the rotor shaft 101 are rotatably supported by the bearing 24 a and the recess 28 a, and the motor unit 10 is disposed in the case 2.

  Further, as shown in FIG. 1, a sleeve 29 is fitted in the fitting hole 27, and one end of the shaft portion 301 is rotatably supported by the sleeve 29, so that the rotation output portion 30 is provided in the case 2. It is arranged. Further, both ends of the gear rotation shaft 201 are rotatably supported by the bearing 24 b and the support hole 26, and the speed reduction unit 20 is disposed in the case 2. In addition, the rotor shaft 101, the gear rotation shaft 201, and the shaft portion 301 are arranged substantially in a straight line in the case 2 in parallel.

  In addition, four mounting holes 21c and 22c are provided in the corners of the case body 21 and the lid 22, respectively. Then, with the cover 22 attached to the case main body 21, by inserting screws and bolts into the attachment holes 21c and 22c, the brushless motor 1 is attached at a predetermined location or incorporated in an external device. be able to. In this embodiment, the cover 22 is configured to be attached to the case body 21 by a concavo-convex structure provided in a one-to-one correspondence with each of the case body 21 and the cover 22.

  As shown in FIG. 1, the motor unit 10 includes a rotor shaft 101 having both ends rotatably supported by a bearing 24a and a recess 28a and rotatably supported by a sleeve 102, a stator 103 formed of a coil, The outer rotor 104 which has the rotor magnet 104a and rotates integrally with the rotor shaft 101 is provided. In this way, by configuring the motor unit 10 as an outer rotor type motor, it is possible to obtain a desired driving torque without increasing the size of the motor unit 10 in the longitudinal direction of the rotor shaft 101 as compared to the inner rotor type. it can. In general, when the same driving torque is obtained for an inner rotor type motor and an outer rotor type motor, the axial length of the stator and rotor of the outer rotor type motor is an inner rotor type motor. This is because it becomes shorter. A rotor gear 105 is fitted near the bottom surface 24 of the outer periphery of the rotor shaft 101 and is configured to mesh with a driven gear 202 of the speed reduction unit 20 described later.

  As shown in FIG. 1, the circuit board 3 is formed to be approximately the same size as the lid 22, and the circuit board 3 is fixedly disposed in close contact with an insulating film over almost the entire surface of the lid 22. As shown in FIG. 5, the circuit board 3 is formed with through holes 3a, 3b, and 3c through which the bearing bush 28, the gear rotation shaft 201, and the shaft portion 301 can be respectively inserted. On the circuit board 3, all driving electronic components such as a Hall element H and a control IC necessary for driving the motor unit 10 are disposed. Thus, by providing all the driving electronic components in the case 2 in an integrated manner, the brushless motor 1 can be driven without providing a driving circuit outside. In addition, the connector 31 is provided at a position near the gear rotation shaft 201 that is narrower than the bearing bush 28 and the shaft portion 301. Thus, by providing the connector 31 in the vicinity of the gear rotation shaft 201 configured to be thin, the space in the case 2 can be used efficiently.

  As shown in FIG. 1, the speed reduction unit 20 includes a gear rotation shaft 201 whose both ends are rotatably supported by a bearing 24 b and a support hole 26, and a gear rotation shaft 201 formed to have a larger diameter than the outer diameter of the outer rotor 104. A driven gear 202 fitted to the outer periphery of the rotor gear 105 and meshed with the rotor gear 105, and a transmission gear 203 attached to the gear rotation shaft 201 and rotating integrally with the driven gear 202. As described above, the gear rotation shaft 201 is arranged in parallel with the rotor shaft 101, and the rotor gear 105 and the driven gear 202 are directly meshed with each other without using the worm gear, which has been conventionally required. The rotational speed of the outer rotor 104 can be reduced with a simple configuration.

  As shown in FIG. 1, the rotation output unit 30 is engaged with a shaft portion 301 rotatably supported by a sleeve 29 and a transmission gear 203 of the speed reduction portion 20 provided on the other end side of the shaft portion 301. An output gear 303 that rotates integrally with the unit 301 is provided. In addition, the sleeve 29 is configured to be loosely sandwiched by a fastener 304 disposed on one end side of the shaft portion 301 and a convex portion 305 formed integrally with the output gear 303. The part 301 is prevented from coming off from the sleeve 29. In addition, a hollow bearing 302 is formed in the shaft portion 301 so that the rotation of the motor portion 10 can be output to an external device via an output shaft (not shown). In addition, as shown in FIG. 2, the bearing 302 is formed in the substantially cylindrical shape by which the side surface was notched.

  The rotation output unit 30 is disposed in the case 2 such that the distance L between the rotation center and the rotation center of the driven gear 202 is shorter than the radius R of the driven gear 202. Therefore, even if the diameter of the driven gear 202 is increased to reduce the rotation speed of the outer rotor 104, the rotation output unit 30 can be disposed closer to the gear rotation shaft 201.

  Further, as shown in FIG. 1, a resin plate 4 is disposed as an “prevention means” of the present invention so as to be extrapolated to the gear rotation shaft 201 and the sleeve 29, and at least the transmission gear 203 and Scattering of lubricant such as grease from the output gear 303 to the circuit board 3 is prevented. As shown in FIG. 6, a through hole 4 a and a through hole 4 b through which the gear rotation shaft 201 and the shaft portion 301 are inserted are formed in the resin plate 4. In addition, as shown in FIG. 1, the through hole 4b is configured to support the sleeve 29 from the outside in a state of being inserted into the sleeve 29, whereby the strength of the sleeve 29 is reinforced and the shaft 29 The part 301 can be supported more reliably and the shaft part 301 can be prevented from tilting.

  The resin plate 4 includes an arcuate portion 41, and the resin plate 4 is disposed in the case 2 so that the outer peripheral portion of the outer rotor 104 of the motor unit 10 is located here. That is, the resin plate 4 is disposed in the case 2 so as to cover the right side portion of the circuit board 3 toward the paper surface of FIG. With such a configuration, the resin plate 4 can prevent the lubricant from scattering from the transmission gear 202 and the output gear 303 to the right side portion of the circuit board 3. On the other hand, since the left portion of the circuit board 3 is covered with the outer rotor 104, it is possible to prevent the lubricant from scattering from the rotor gear 105 and the driven gear 202 to the left portion of the circuit board 3.

  The resin plate 4 is formed with a locking claw 4c. The resin plate 4 is fixedly disposed in the case 2 by being fitted into the side groove 21a formed on the inner side wall of the case body 21 described above. Is done.

  As described above, in the above-described embodiment, since the motor unit 10 is an outer rotor type, a sufficient driving torque can be obtained even if the rotor shaft 101 is shorter than the inner rotor type. Therefore, since the rotor shaft 101 can be configured to be short, even if the rotor shaft 101, the gear rotation shaft 201, and the shaft portion 301 are arranged substantially in parallel, it is possible to prevent the axial thickness of the brushless motor 1 from increasing. . Further, by arranging the rotor shaft 101, the gear rotation shaft 201, and the shaft portion 301 substantially in parallel, it is possible to reduce the rotation of the outer rotor 104 with a simple configuration without providing a worm gear that has been conventionally required. 20 and the rotation output unit 30. Further, the rotation output portion 30 is rotatably supported at one end of the shaft portion 301 by the sleeve 29 provided in the case 2, and the distance between the rotation center of the shaft portion 301 and the rotation center of the driven gear 202. L is disposed in the case 2 so that L is shorter than the radius R of the driven gear 202. Therefore, the case 2 can be made compact by arranging the speed reduction unit 20 and the rotation output unit 30 closer to each other, and the brushless motor 1 can be made compact.

  Further, since the circuit board 3 formed to be approximately the same size as the lid 22 is disposed in close contact with the entire surface of the lid 22 made of metal, the motor unit 10 provided on the circuit board 3 is driven. Even if the electronic component generates heat, the generated heat can be efficiently radiated to the outside of the case 2 through the lid 22.

  Further, the resin plate 4 can prevent the lubricant from scattering from the transmission gear 202 and the output gear 303 in the case 2 to the circuit board 3.

  Further, since the rotor shaft 101, the gear rotation shaft 201, and the shaft portion 301 are arranged in a substantially straight line in the case 2, the brush 2 can be provided with a narrow width by configuring the case 2 to be thin.

  In addition, since the connector 31 is provided outside the case 2 at a position near the gear rotation shaft 201 on the circuit board 3 so that the external apparatus and the circuit board 3 can be electrically connected, The brushless motor 1 can be easily electrically connected.

  The present invention is not limited to the above-described embodiment, and various modifications can be made to the above-described one without departing from the spirit of the present invention. For example, the gears 105, 202, 203, and 303 may be formed integrally with resin, or individually formed on the shafts 101, 201, and 301.

  The “outer rotor type brushless motor with gear mechanism” of the present invention can be used in various devices, and is particularly preferably employed in OA devices such as printers that require a compact gear mechanism.

It is a cutting front view of the outer rotor type brushless motor with a gear mechanism of the present invention. It is an external view of the outer rotor type brushless motor with a gear mechanism of FIG. It is a figure which shows a case main body. It is a figure which shows a lid | cover. It is a figure which shows the circuit board for drive control. It is a figure which shows a resin board.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Outer rotor type brushless motor with a gear mechanism 10 Motor part 101 Rotor shaft 104 Outer rotor 105 Rotor gear 2 Case 22 Lid (one side)
24 Bottom (other side)
20 speed reduction part 201 gear rotation shaft 202 driven gear 203 transmission gear 3 drive control circuit board 31 connector 30 rotation output part 301 shaft part 303 output gear 4 resin plate (prevention means)

Claims (6)

A motor unit having a case, a rotor shaft whose both ends are rotatably supported by one surface and the other surface of the case facing each other, and an outer rotor that rotates integrally with the rotor shaft When,
A circuit board for driving control of the motor unit disposed fixedly on the one surface side in the case;
Both ends of the rotor shaft are rotatably supported by the one surface and the other surface of the case, and are fitted in the outer periphery of the rotor shaft near the other surface, and a gear rotation shaft disposed in the case in parallel with the rotor shaft. A rotor gear, a driven gear that has a larger diameter than the outer diameter of the outer rotor, is fitted on the outer periphery of the gear rotation shaft and meshes with the rotor gear, and is attached to the gear rotation shaft and integrated with the driven gear. A speed reducer having a rotating transmission gear;
A shaft portion disposed in the case in parallel with the rotor shaft and the gear rotation shaft and having one end rotatably supported on the one surface, and the transmission gear provided on the other end side of the shaft portion; A rotation output portion having an output gear that meshes with and rotates integrally with the shaft portion,
The rotation output unit is disposed in the case such that the distance between the rotation center of the rotation output unit and the rotation center of the driven gear is shorter than the radius of the driven gear. With outer rotor type brushless motor. At least the one surface of the case is made of metal,
The outer rotor brushless motor with a gear mechanism according to claim 1, wherein the circuit board is disposed in close contact with the one surface of the case.   3. The gear mechanism according to claim 2, wherein the circuit board is formed to have substantially the same size as the one surface of the case, and is disposed in close contact over substantially the entire surface of the one surface. Outer rotor type brushless motor.   The gear mechanism according to any one of claims 1 to 3, further comprising prevention means for preventing scattering of lubricant from the transmission gear and the output gear in the case to the circuit board. Outer rotor type brushless motor.   5. The outer rotor brushless motor with a gear mechanism according to claim 1, wherein the rotor shaft, the gear rotation shaft, and the shaft portion are arranged substantially in a straight line in the case. . A connector is disposed at a position near the gear rotation axis on the circuit board,
6. The connector according to claim 1, wherein the connector is provided to be exposed outside the case so that an external device and the drive control circuit board can be electrically connected. Outer rotor type brushless motor with gear mechanism.

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