JP6226667B2 - motor - Google Patents

Description

  The present invention relates to a motor used in a power transmission device such as an elevator door opening / closing drive device.

Conventionally, a power transmission device is mainly configured by a power transmission belt, a drive pulley, and a motor. For example, in opening / closing driving of an elevator door, the output of the motor is decelerated by a feeding belt and a driving pulley, and the timing belt for opening / closing the elevator door is driven by the reduction ratio. As the motor, an inner rotor type or outer rotor type motor is used as a drive source. As an outer rotor type motor, for example, there is a motor described in JP-A-2004-001982. As a motor for an elevator door driving device, a flat brushless motor in which the outer diameter of the motor is larger than the axial height of the stator core is used.
JP 2004-001982 A

  For example, in the case of an elevator door drive device, it is necessary to accurately grasp the movement of the motor in order to realize a fine opening / closing operation of the door. Therefore, in addition to the hall sensor, a position detection element such as an encoder is further mounted on the motor to accurately detect the position of the motor. Moreover, in the elevator door opening / closing drive device, it is also required to reduce the axial length of the entire device by reducing the thickness of the motor.

  In the outer rotor type motor described in JP 2004-001982 A, the following configuration is disclosed. In the stator, a coil is wound around an iron core having radial slots, and a cylindrical wall of a bracket protruding from the front side in the axial direction is integrally coupled to the inner peripheral side of the iron core. On the other hand, the rotor has a cylindrical peripheral wall portion provided with permanent magnets facing each other with a predetermined gap on the outer peripheral side of the stator, and a shaft portion supported via a bearing on the inner cylindrical wall of the stator. And a connecting wall connected to the shaft portion around the rear side in the axial direction. The shaft portion passes through the stator and the cylindrical wall, and the tip protrudes forward of the cylindrical wall (paragraph 0017).

  In the motor described in Japanese Patent Application Laid-Open No. 2004-001982, when an encoder is attached, it is necessary to increase the axial height of the stator iron core in order to secure an arrangement space for the encoder. Therefore, there is a restriction that the axial height of the motor also increases.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to mount a rotated position detecting portion in a shaft receiving portion when a position detecting element and a rotated position detecting portion for accurately detecting a rotor position are mounted on a motor, An object of the present invention is to provide a motor capable of reducing the axial thickness of the motor by overlapping the position detection unit and the bearing member in the radial direction.

  A motor that solves the above problem includes a stationary part, and a rotating part that is rotatably supported about a central axis that extends vertically with respect to the stationary part, and the stationary part rotates the shaft. A bearing member that supports the bearing member; a mounting plate that holds the bearing member from a radially outer side; an armature that is directly or indirectly held by the mounting plate on a radially outer side of the bearing member; A circuit board disposed on the lower side of the child, and the rotating part includes a shaft disposed along the central axis, a rotor holder fixed to the shaft, and a rotor magnet fixed to the rotor holder And the circuit board includes a rotation position detection element that detects a rotation position of the rotation portion, and the rotation position detection element is disposed below the lower end in the axial direction of the rotor magnet, and the bearing portion And at least one of the rotor magnet and the armature overlaps in the radial direction, the output side end of the shaft projects from the upper side of the rotor holder, and the shaft is rotated at the lower end in the axial direction. It has an accommodating part which accommodates a detecting part.

  According to the first exemplary invention of the present invention, in the motor equipped with the position detection element for accurately detecting the rotor position, at least one of the bearing member, the rotor magnet, and the armature overlaps in the radial direction. Further, it is possible to reduce the axial thickness of the motor while securing an arrangement space for mounting the rotational position detecting element.

FIG. 1 is a longitudinal sectional view of a motor according to the first embodiment. FIG. 2 is a perspective view of the mounting plate according to the first embodiment. FIG. 3 is a bottom view of the motor according to the first embodiment. FIG. 4 is a longitudinal sectional view of a shaft and a bearing member according to a modification. FIG. 5 is a longitudinal sectional view of a motor according to the second embodiment.

  Hereinafter, exemplary embodiments of the present invention will be described. In this application, the direction parallel to the central axis of the motor is the “axial direction”, the direction orthogonal to the central axis of the motor is the “radial direction”, and the direction along the arc centered on the central axis of the motor is the “circumferential direction”. , Respectively. Further, in the present application, the shape and positional relationship of each part will be described with the axial direction being the vertical direction and the bearing member side facing the rotating part. However, the definition of the vertical direction is not intended to limit the orientation of the motor according to the present invention during manufacture and use.

  Further, in the present application, the “parallel direction” includes a substantially parallel direction. Further, in the present application, the “perpendicular direction” includes a substantially orthogonal direction.

<1. First Embodiment>
This will be described with reference to FIGS. FIG. 1 is a longitudinal sectional view of a motor 1 according to a first embodiment of the present invention. FIG. 2 is a perspective view of the mounting plate 31. The motor 1 is a brushless motor used as a drive source for general industrial equipment such as an elevator door drive device. As shown in FIG. 1, the motor 1 has a rotating part 2 and a stationary part 3.

  The rotating part 2 is supported rotatably about a central axis J1 extending vertically. The rotating unit 2 includes a shaft 21, a rotor holder 22, and a rotor magnet 23. The shaft 21 is disposed along the central axis J <b> 1 and is rotatably supported by the bearing member 33. For example, a metal such as stainless steel is used as the material of the shaft 21. The shaft 21 includes a medium diameter part 211, a large diameter part 212, an output part 213, and a storage part 214. The medium diameter portion 211 has the lower end of the shaft 21 and is supported by a bearing member 33 described later. The large diameter portion 212 is located on the upper side in the axial direction than the medium diameter portion 211. The outer diameter of the large diameter portion 212 is larger than the outer diameter of the medium diameter portion 211. The output part 213 is positioned on the upper side in the axial direction than the large diameter part 212. The output part 213 has an outer diameter smaller than that of the large diameter part 212. The output part 213 protrudes from a lid part 222 of the rotor holder 22 described later. The middle diameter portion 211 has a housing portion 214 that is recessed toward the upper end in the axial direction. In the accommodation unit 214, a rotated position detection unit 500 described later is arranged.

  For example, a driving pulley 80 is mounted on the outer side in the radial direction of the output unit 213. The driving torque of the motor is transmitted from the rotating unit 2 to the driving pulley 80 via the shaft 21. By rotating the driving pulley 80, a feeding belt (not shown) is fed and moved, and for example, the elevator door is driven to open and close at a direction and speed according to the generated torque.

  The rotor holder 22 is attached to the upper side of the shaft 21 in the axial direction. The rotor holder 22 includes a shaft fixing portion 221, a lid portion 222, and a cylindrical portion 223. The shaft fixing portion 221 has a cylindrical shape extending from the center of the lid portion 222 to the upper side in the axial direction along the shaft 21. The shaft fixing portion 221 is fixed to the large diameter portion 212 of the shaft 21. The lid portion 222 has a disk shape that spreads radially outward from the lower end of the shaft fixing portion 221. The cylindrical portion 223 extends downward from the outer edge of the lid portion 222.

For example, in an elevator apparatus, it is necessary to increase the reduction ratio and increase the torque of the power transmission device. Therefore, it is necessary to improve the fixing strength of the rotor holder 22 with respect to the shaft 21. Therefore, by increasing the outer diameter of the large-diameter portion 212 of the shaft 21 in contact with the rotor holder 22, the contact area between the large-diameter portion 212 and the shaft fixing portion 221 can be increased. Thereby, the fixing strength of the rotor holder 22 to the shaft 21 can be further increased.
In the present embodiment, since the outer diameter of the large diameter portion 212 is larger than the outer diameter of the output portion 213, the reduction ratio can be increased. The motor 1 has a larger reduction ratio than the motor in which the outer diameter of the output portion 213 protruding from the lid portion 222 of the rotor holder 22 is equal to the outer diameter of the large diameter portion 212. As a result, a large torque necessary for opening and closing the elevator door can be obtained via the drive pulley and the feeding belt.
That is, according to the motor 1 of this embodiment, in the flat motor, the reduction ratio required for opening / closing driving of the elevator door can be obtained while the axial height of the motor 1 is reduced, and the shaft fixing portion 221 can be driven. The fixing strength of the rotor holder 22 can also be increased.
Here, the flat type means that the outer diameter of the rotor holder 22 is larger than the axial height of the stator core 321.

  The rotor magnet 23 is fixed inside the cylindrical portion 223 in the radial direction. The rotor magnet 23 may be cylindrical, or a plurality of magnets arranged in the circumferential direction.

  The rotating unit 2 is assembled by fixing the rotor holder 22 to the shaft 21, mounting the rotor magnet 23 on the inner peripheral surface of the rotor holder 22, and mounting the rotated position detection unit 500 in the housing portion 214 of the shaft 21. When a rotational position detecting element such as an encoder is mounted on the motor in addition to the hall sensor, an encoder magnet 501 described later is accommodated in the accommodating portion 214 of the shaft 21. Therefore, the accommodating part 214 has an internal dimension in which at least a part of the encoder magnet 501 can be inserted.

  The stationary part 3 includes a mounting plate 31, an armature 32, a bearing member 33, and a circuit board 40. The mounting plate 31 includes a base portion 311 and a bearing support portion 312. The base 311 supports the armature 32. The base 311 has a recess 313 on the upper surface of the mounting plate 31. The bearing support portion 312 is disposed coaxially with the central axis J1. The bearing support portion 312 extends axially upward from the base portion 311 and supports the bearing member 33 on the inner surface.

  The mounting plate 31 and the armature 32 are held directly or indirectly on the radially outer side of the bearing member 33. In the present embodiment, the mounting plate 31 and the armature 32 are fixed to each other via the armature fastening member 34. The armature fastening member 34 is positioned in the axial range between the uppermost end of the first bearing member 331 and the axially lower surface of the circuit board 40 on the radially outer side of the bearing member 33 described later. Thereby, the axial direction height of a motor can be reduced. In the present embodiment, the armature fastening member 34 is not limited to a screw as long as it fixes the mounting plate 31 and the armature 32, and members such as eyelets and rivets may be used.

  The armature 32 includes a stator core 321, an insulator 323, and a coil 322. The stator core 321 has an annular core back disposed substantially coaxially with the central axis J1 and a plurality of teeth projecting radially outward from the core back. The stator core 321 is formed by laminating a plurality of magnetic steel plates in the vertical direction. The teeth of the stator core 321 face the rotor magnet 23. The insulator 323 covers a portion of the stator core 321 excluding the inner peripheral surface. A conductive wire is wound around each tooth via an insulator 323, and a coil 322 that applies a magnetic field to the rotating unit 2 is configured. The insulator 323 may have any shape as long as it covers a portion of the stator core 321 around which the coil 322 is wound.

  The bearing member 33 is a ball bearing. The bearing member 33 is disposed on the lower side in the axial direction with respect to the lid portion 222 of the rotor holder 22. Further, the bearing member 33 is disposed on the radially inner side of the rotor holder 22. The bearing member 33 and the rotor magnet 23 overlap in the radial direction. It is more preferable that the bearing member 33 overlaps both the rotor magnet 23 and the armature 22 in the radial direction because the axial height of the motor can be reduced. However, the bearing member 33 overlaps at least one of them. Just do it.

The bearing member 33 includes a first bearing member 331 and a second bearing member 332. The first bearing member 331 is located above the second bearing member 332. The inner ring at the upper end of the first bearing member 331 is in contact with the lower end surface of the large diameter portion 212 of the shaft 21. The outer diameter of the large-diameter portion 212 of the shaft 21 is larger than the inner diameter and outer diameter of the inner ring of the first bearing member 331 and smaller than the inner diameter of the outer ring. The lower end surface of the large diameter portion 212 is in contact with the inner ring of the first bearing member 331. By making the outer diameter of the large diameter portion 212 larger than the inner diameter and outer diameter of the inner ring of the first bearing member 331, the fixing strength of the rotor holder 22 with respect to the shaft 21 can be increased. Furthermore, since the lower end surface of the large diameter portion 212 is in contact with the inner ring of the first bearing member 331, the height of the motor 1 in the axial direction can be reduced. When it is desired to reduce the axial height of the motor 1, a step portion 212 </ b> A that is recessed radially inward may be formed on the lower end surface of the large diameter portion 212 as shown in FIG. 4. In FIG. 4, the large-diameter portion 212 has a step portion 212A and a rotor holder fixing portion 212B. The rotor holder fixing part 212 </ b> B is in contact with the shaft fixing part 221 of the rotor holder 22. The outer diameter of the step portion 212A is larger than the inner diameter and outer diameter of the inner ring of the first bearing member 331 and smaller than the inner diameter of the outer ring. The outer diameter of the rotor holder 221B is larger than the outer diameter of the step portion 212A. Further, the lower end surface of the step portion 212 </ b> A is in contact with the inner ring of the first bearing member 331. Since the outer diameter of the step portion 212A is larger than the inner diameter and outer diameter of the inner ring of the first bearing member 331, the contact area between the rotor holder fixing portion 212B and the shaft fixing portion 221 having a larger outer diameter than the step portion 212A is large. Therefore, the fixing strength of the rotor holder 22 with respect to the shaft 21 can be increased.
The first bearing member 331 and the second bearing member 332 are in contact with each other in the axial direction. The upper end of the first bearing member 331 is located on the upper side in the axial direction from the upper end portion 231 of the rotor magnet 23. The lower end of the second bearing member 332 is positioned below the lower end portion 232 of the rotor magnet 23 in the axial direction. The second bearing member 332 is positioned in the axial direction of the second bearing member 332 by contacting the bearing support portion 312 of the mounting plate 31. The outer ring of the first bearing member 331 is supported by the fixing member 60. The upper end surface of the fixing member 60 is in contact with the bearing support portion 312. For example, a metal C-ring is used as the fixing member 60. A bearing retainer 61 that supports the second bearing member 332 is attached to the lower end of the shaft 21. The bearing retainer 61 is, for example, a metal C-ring. Thereby, the positioning accuracy of the first bearing member 331 and the second bearing member 332 is improved. The inner ring of the first bearing member 331 and the inner ring of the second bearing member 332 are supported by the medium diameter portion 211 of the shaft 21. The inner ring of the first bearing member 331 and the inner ring of the second bearing member 332 need not be in contact with each other. When there is a gap in the axial position between the first bearing member 331 and the second bearing member 332, the gap is smaller than the radial outer diameter of each bearing member 33. Therefore, the axial height of the motor 1 can be further reduced.

  FIG. 3 is a bottom view of the motor 1 in the present embodiment. With reference to FIGS. 1 to 3, the circuit board 40 is disposed below the armature 32. The circuit board 40 is fixed to the base 311 of the mounting plate 31 and faces the bearing member 33 in the axial direction. The circuit board 40 has an annular shape centered on the central axis J <b> 1 and is fixed to the base 311 by a circuit board fastening member 341. Torque is generated between the armature 32 and the rotor magnet 23 by causing a current to flow from the circuit board 40 to the coil 322. Thereby, the rotation part 2 rotates centering on the central axis J1.

  The circuit board 40 includes an encoder board 400 and a sensor board 401. The sensor substrate 401 has a substantially arc shape, and is fixed to the lower end portion in the axial direction of the insulator 323 via the sensor substrate fastening member 42. The lower end portion of the sensor board fastening member 42 is accommodated in the recess 313 of the mounting plate 31. Therefore, the height of the motor 1 in the axial direction can be reduced as compared with a motor that employs the mounting plate 31 without the recess 313. The sensor board fastening member 42 is a screw. However, the sensor board 401 and the insulator 323 are not limited to screws as long as the sensor board 401 and the insulator 323 are fixed, and may be a member such as an eyelet or a rivet.

  On the upper surface of the sensor substrate 401, a hall sensor (a hall element or hall IC, not shown) is mounted in the vicinity of the rotor magnet 23. The hall sensor detects a magnetic field generated from the rotor magnet 23. Thereby, the rotation position of the rotation part 2 is detected.

  The encoder substrate 400 is a substantially circular substrate. The encoder substrate 400 is disposed on the lower side in the axial direction than the lower end portion 231 of the rotor magnet 23. The encoder board 400 has a rotational position detection element 70. The rotational position detecting element 70 faces an encoder magnet 501 described later in the axial direction. The rotational position detecting element 70 can detect the rotational speed and rotational position of the rotating unit 2 in cooperation with the encoder magnet 501. The rotational position detection element 70 is, for example, a hall sensor.

  The rotated position detection unit 500 is housed in the housing portion 214 of the shaft 21. The rotated position detection unit 500 includes an encoder magnet 501 that detects the rotation angle and rotation speed of the shaft 21 and a magnet holder 502 that holds the encoder magnet 501. The encoder board 400 and the encoder magnet 501 are arranged to face each other in the axial direction. The axial position of the encoder magnet 501 overlaps with the bearing member 33 in the radial direction. The magnet holder 502 has a substantially cylindrical shape. In this embodiment, there is one encoder magnet 502 and one magnet holder 502.

  In the motor 1, the output portion 213 of the shaft 21 protrudes from the lid portion 222 of the rotor holder 22, and the encoder magnet 501 and the bearing member 33 overlap in the radial direction, whereby the rotational position detection element 70 is mounted in the motor 1. In addition, it is possible to reduce the thickness of the motor 1 in the axial direction by storing the encoder magnet 501 in the storage portion 214 of the shaft 21 while securing an arrangement space for this purpose.

<2. Other embodiments>
As mentioned above, although exemplary embodiment of this invention was described, this invention is not limited to the said embodiment. FIG. 5 is a view showing a configuration of a motor according to another embodiment of the present invention.

  As shown in FIG. 5, the motor of the present invention may be an inner rotor type motor 1A. In the case of an inner rotor type motor, the rotor magnet 23A is arranged on the radially inner side of the stator core 321A.

  The rotational position detecting element 70 may be a light emitting element such as an LED, and the rotated position detecting unit 500 may be a light receiving element such as a photodiode. Further, the circuit board 40 may be one or three or more.

  The output portion 213A may have an outer diameter smaller than that of the large diameter portion 212A and may be larger than that of the middle diameter portion 211A.

  In addition, about the detailed structure of a motor, you may differ from the structure shown by each figure of this invention. Moreover, you may combine suitably each element which appeared in the said embodiment and modification in the range which does not produce inconsistency.

  The present invention can be used for a motor.

DESCRIPTION OF SYMBOLS 1, 1A Motor 2 Rotating part 3 Stationary part 21 Shaft 211, 211A Medium diameter part 212, 212A Large diameter part 213, 213A Output part 214 Storage part 22 Rotor holder 221 Shaft fixing part 222 Cover part 223 Cylindrical part 23, 23A Rotor magnet 31 Mounting plate 311 Base 312 Bearing support 313 Recess 32 Armature 321, 321A Stator core 322 Winding 323 Insulator 33 Bearing member 34 Armature fastening member 40 Circuit board 400 Encoder board 401 Sensor board 500 Rotated position detector 501 Encoder magnet 502 Magnet Holder 60 Fixing member 61 Bearing retainer 70 Rotation position detecting element 80 Drive pulley

Claims (12)

A stationary part;
A rotating part supported to be rotatable about a central axis extending vertically with respect to the stationary part;
With
The stationary part is
A mounting plate;
An armature that is held directly or indirectly by the mounting plate on the outside in the radial direction of the mounting plate;
A bearing member held inside in the radial direction of the mounting plate;
A circuit board disposed under the armature;
Have
The rotating part is
A shaft rotatably supporting the bearing member and disposed along the central axis;
A rotor holder fixed to the shaft;
A rotor magnet fixed to the rotor holder;
Have
The circuit board includes a rotation position detection element that detects a rotation position of the rotation unit,
The rotational position detection element is arranged below the lower end in the axial direction of the rotor magnet,
The bearing member and at least one of the rotor magnet and the armature overlap in the radial direction,
The output side end of the shaft protrudes from the upper side of the rotor holder,
The shaft is a motor having an accommodating portion for accommodating a rotated position detecting portion at a lower end portion in the axial direction. The motor according to claim 1,
The motor according to claim 1, wherein the rotational position detection unit and the bearing member overlap in a radial direction. The motor according to claim 1 or 2,
The rotor holder has a substantially cylindrical shape with a lid,
The rotor magnet is held by a cylindrical portion of the rotor holder,
The motor is characterized in that the bearing member is disposed on the lower side in the axial direction with respect to the lid portion of the rotor holder. The motor according to claim 3, wherein
The motor according to claim 1, wherein the bearing member is disposed radially inward of the rotor holder. The motor according to claim 1,
The bearing member has a first bearing member and a second bearing member;
The upper end of the first bearing member is positioned on the lower side in the axial direction than the upper end of the armature or the rotor magnet,
The motor characterized in that the lower end of the second bearing member is positioned on the upper side in the axial direction than the lower end of the armature or the rotor magnet. The motor according to any one of claims 1 to 5,
The bearing member has a first bearing member and a second bearing member;
A motor characterized in that an axial distance between the first bearing member and the second bearing member is smaller than a radial outer diameter of the bearing member. The motor according to claim 6, wherein
The first bearing member is positioned above the second bearing member;
The motor according to claim 1, wherein the first bearing member is in contact with the second bearing member in the axial direction.
The motor according to claim 5 or 6 ,
The mounting plate has a base portion and a bearing support portion extending axially upward from the base portion,
The bearing support portion holds a fixing member that comes into contact with the upper end surface in the axial direction of the first bearing member,
A motor characterized in that the first bearing member is held by the fixing member.
The motor according to any one of claims 1 to 8,
The motor according to claim 1, wherein the rotational position detecting element and the rotational position detecting unit are arranged to face each other in the axial direction.
The motor according to any one of claims 1 to 9,
The armature includes an annular core back,
Teeth protruding radially from the core back;
A stator core having
A coil configured by winding a winding around the teeth;
An insulator partially covering the surface of the teeth;
Have
The circuit board has a sensor board,
The sensor substrate is fixed to the lower side in the axial direction of the insulator via a substrate fastening member,
The mounting plate has a recess on the upper surface in the axial direction,
The motor according to claim 1, wherein a lower end portion of the substrate fastening member is accommodated in the recess. The motor according to claim 3 or 4,
The rotor magnet is disposed on the radially inner side of the rotor holder,
The motor according to claim 1, wherein the armature is disposed radially inside the rotor magnet. The motor according to claim 5 , wherein
The mounting plate is fixed by the armature and an armature fastening member,
The motor according to claim 1, wherein the armature fastening member is located outside in a radial direction of the bearing member and within an axial range between an uppermost end of the first bearing member and an axially lowermost end of the circuit board.

Images