JP2008259316A - Motor and driving device for vehicle opening/closing bodies using the motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor having a reverse rotation preventing function wherein motor efficiency is maintained and influence on noise, size, weight, and manufacturing cost can be reduced and a driving device for vehicle opening/closing bodies using the motor. <P>SOLUTION: The motor 2 includes: a rotating shaft 5; a motor case 3 that houses and rotatably supports the rotating shaft; a rotor 6; and a stator. The rotor is obtained by winding an armature coil on multiple teeth 8 that are provided integrally with the rotating shaft and radially with respect to the rotating shaft and respectively have at their tips a flange 8a protruded toward the circumference of the rotating shaft. The stator has a magnet 7 of multiple magnetic poles placed on the inner circumferential surface of the motor case so that it is opposed to the outer circumferential surface of the rotor and multiple magnetic poles are formed on the inner circumferential surface of the motor case 3. When the motor is not energized, the teeth are placed in positions opposite the areas between the magnetic poles of the magnet in the circumferential direction. Multiple teeth whose flange is partly cut are included in the above teeth so that they are symmetric with respect to the rotating shaft. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an electric motor and an electric motor used in a drive device for a vehicle opening / closing body, and more specifically, an electric motor capable of self-holding a rotation stop position of the electric motor to prevent reverse rotation and the electric motor. The present invention relates to a drive device for a vehicle opening / closing body that can hold a stop position of the used vehicle opening / closing body.

  Conventionally, an electric motor has been used as a drive source for a power window of an automobile. These motors receive external force from the driven member side, that is, when the rotor rotates by applying external force from the outside of the window glass, the window glass may open and close. Measures are taken to prevent motor rotation.

For example, a thrust bearing made of resin is fixed to the axial end surface of the motor rotation shaft, the contact tip surface of the thrust bearing can be brought into contact with the plate of the opposite part of the motor case, and the rotation shaft is axially moved by an external force. In the case of displacement, there was one that generated a frictional force between the contact surface between the tip of the thrust bearing and the plate, thereby generating a force (braking force) that prevents opening and closing of the window from the outside ( For example, see Patent Document 1).
JP 61-36476 A

  However, with the conventional structure described above, it is possible to prevent the window glass from being opened and closed by an external force from the outside of the window glass. Since a force is generated and becomes a resistance, there is a problem that a motor with a large output must be obtained in order to obtain a desired motor driving efficiency. In addition, there is a problem that noise is generated due to friction and a problem that the manufacturing cost increases because it is necessary to use an expensive resin material because a resin thrust bearing requires wear resistance.

  The present invention has been made in view of the above problems, and is an electric motor having a reverse rotation prevention function that reduces the influence on noise while maintaining the driving efficiency of the motor, and is small, light, and inexpensive to manufacture. It is an object of the present invention to provide a motor and a driving device for a vehicle opening / closing body using the motor.

  In order to solve the above-mentioned problem, the invention according to claim 1 includes a rotating shaft 5, a motor case 3 including and supporting the rotating shaft 5, an integral body with the rotating shaft 5, and the rotating shaft. A rotor 6 in which an armature coil is wound around a plurality of teeth 8 provided radially with respect to 5 and provided with flanges 8a projecting in the circumferential direction of the rotary shaft 5 at each tip thereof; and the motor case A stator having a plurality of magnetic pole magnets 7 disposed on the inner peripheral surface of the motor case 3 so as to face the outer peripheral surface of the rotor 6 in order to form a plurality of magnetic poles on the inner peripheral surface of the motor 3. In the electric motor 2 having the electric motor 2, the flange portion 8 a is partially cut out of the plurality of teeth 8 positioned at positions opposed to the magnetic poles in the circumferential direction of the magnet 7 in a non-energized state of the electric motor 2. The rotating tooth 5 Characterized in that it comprises a plurality so as to be symmetrical against.

  The invention according to claim 2 is the invention according to claim 1, wherein the teeth in which a part of the flange portion 8 a is cut off are intermediate portions of the flange portion 8 a in the axial direction of the rotating shaft 5. Is cut out.

  The invention according to claim 3 is the invention according to claim 1 or 2, characterized in that both end surfaces in the axial direction of the rotating shaft 5 are supported by the motor case 2 via steel balls 10. And

  The invention according to claim 4 is the invention according to any one of claims 1 to 3, wherein the teeth 8 are provided integrally with the rotary shaft 5 with a skew angle.

  The invention according to claim 5 is a vehicle opening / closing body drive device 1 that opens and closes the vehicle opening / closing body by the electric motor 2, and the drive device 1 outputs the electric motor 2 and the rotation of the electric motor 2. The output shaft 9a and a power transmission mechanism for transmitting the rotation of the output shaft 9a to the vehicle opening / closing body. The electric motor 2 includes the rotary shaft 5 and the rotary shaft 5 so as to support the shaft. A plurality of teeth that are provided integrally with the rotating shaft and radially with respect to the rotating shaft 5, and are provided with flange portions 8 a projecting in the circumferential direction of the rotating shaft 5. The inner surface of the motor case 3 is opposed to the outer peripheral surface of the rotor 6 in order to form a plurality of magnetic poles on the inner peripheral surface of the rotor 6 and the motor case 3. A plurality of magnetic pole magnets 7 disposed on the peripheral surface are provided. An electric motor 2 having a stator, wherein the teeth 8 are partially cut out of the plurality of teeth 8 in a range corresponding to the magnetic pole spacing in the circumferential direction of the magnet. A plurality are included so as to be symmetric with respect to the axis 5.

  The invention according to claim 6 is the invention according to claim 5, wherein the teeth 8 in which a part of the flange portion 8 a is cut off have an intermediate portion in the axial direction of the flange portion 8 a on the rotating shaft. It is cut out.

  The invention according to claim 7 is the invention according to claim 5 or 6, wherein both end faces in the axial direction are supported by the motor case 3 via steel balls 10.

  An invention according to an eighth aspect is the invention according to any one of the fifth to seventh aspects, wherein the teeth 8 are provided integrally with the rotary shaft 5 with a skew angle.

  The invention according to claim 9 is the invention according to any one of claims 5 to 8, wherein the rotor 6 includes ten teeth 8, and the magnet 7 is provided on the rotating shaft 5. A range having two arc arc angles corresponding to three teeth 8 continuous in the circumferential direction and two symmetrical positions with respect to the rotating shaft 5 and corresponding to the circumferential magnetic pole spacing of the two magnets 7 The four teeth 8 out of the ten teeth 8 in FIG. 4 are the teeth 8 in which a part of the flange portion 8a is cut off.

  According to the first aspect of the present invention, the teeth that do not have the brim portion are formed on a part of the teeth of the rotor, so that the cogging torque of the motor generated by the magnetic flux between the rotor and the magnet is increased by this part. Become. Since the main factor that generates the cogging torque is a groove (slot) between the ridges of the teeth, removing the ridge increases the distance between the teeth and increases the cogging torque. In addition, in order to ensure that a plurality of teeth that do not have a collar portion are disposed at positions facing between the magnetic poles of the electric motor when the electric motor is not energized, the teeth that do not have a collar portion are adjacent to a predetermined position. As a result, the interval between the portions where the flanges do not exist is widened, and a larger cogging torque is generated. Therefore, in order to rotate the motor in a non-energized state of the electric motor, it is necessary to apply a force that overcomes the cogging torque, so that it effectively works to prevent the motor from reversing due to an external force.

  In addition, since the teeth that do not have a collar gather at positions opposite to the magnetic poles of the magnet when the electric motor is not energized, the magnitude of the cogging torque with respect to the rotation of the motor depends on the number of poles. Will change greatly. In the cycle, there are two directions in which cogging torque is applied, a direction for preventing rotation and a direction for promoting rotation, which are alternately repeated. Therefore, a large cogging torque can be generated at a certain rotational position when the motor is stopped, and a cogging torque can be generated in a direction that promotes the rotational direction while keeping the cogging torque low at other rotational positions. The motor rotation efficiency can be kept high. Further, by arranging the teeth having no flanges symmetrically with respect to the rotation axis, it is possible to minimize the vibration generated in the motor while minimizing the deterioration of the magnetic and weight balance. With this effect, the deterioration of noise generated from the motor can be minimized.

  According to the invention of claim 2, since the notch position of the collar portion is provided in an intermediate portion in the axial direction of the tooth rotation shaft, the collar portion is provided at both ends in the tooth rotation axis direction and is wound around the tooth. The armature coil can be reliably held without causing collapse.

  According to the invention of claim 3, since both end surfaces of the rotating shaft in the axial direction are supported via the steel balls, the manufacturing cost of the motor can be reduced. As described above, conventionally, when a rotation prevention function is added to a motor, an expensive resin thrust bearing is used to generate a frictional force at the axial end portion of the rotating shaft. According to the first aspect of the invention, the motor can be prevented from reversing due to an external force using the cogging torque of the motor, so that it is not necessary to generate a frictional force in the bearing portion, and it is not necessary to use an expensive resin bearing. Therefore, an inexpensive steel ball bearing can be used, the bearing structure is simplified, and the entire motor can be reduced in size and weight. In addition, the steel ball support structure can reduce friction and maintain high motor efficiency.

  According to the invention of claim 4, by providing the skew angle, harmonic loss can be reduced, and vibration and noise during motor driving can be reduced.

  According to the invention of claim 5, it is possible to obtain a drive device for a vehicle opening / closing body using the electric motor according to the invention of claim 1. When the driving device according to the present invention is provided for driving a vehicle opening / closing body, the electric motor of the driving device has a rotation preventing function using cogging torque in the non-energized state, so that the vehicle opening / closing body is opened and closed. Even if an external force is applied, the electric motor resists the external force and does not rotate, so that the opening / closing body does not open / close. Therefore, the crime prevention function is demonstrated.

  The sixth, seventh, and eighth aspects of the invention provide the vehicle opening / closing body drive device of the fifth aspect with the same effects as those of the second, third, and fourth aspects of the invention.

  The invention according to claim 9 provides an optimum configuration of the drive device for the vehicle opening / closing body according to claims 5 to 8.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of an electric motor used in an electric motor to which the present invention is applied and a drive device for a vehicle power window as a vehicle opening / closing body. 2 is a cross-sectional view showing a motor and a power window device for an automobile using the motor as viewed from an arrow X in FIG. FIG. 3 is a perspective view showing the tooth shape of the rotor of the motor according to the present embodiment. FIG. 4 is a diagram showing a waveform of cogging torque.

  As shown in FIG. 1, an electric motor 1 used in an automotive power window driving device as a driving device for a vehicle opening / closing body includes a motor unit 2 and a speed reduction mechanism 4 integrally connected to a motor case 3 of the motor unit 2. And a reduction gear case 12 that performs the same. A rotating shaft 5 supported in the motor unit 2 is supported by a radial bearing 3a and a thrust bearing 3b provided at the bottom of the motor case 3 having one end formed in a bottomed cylindrical shape. The projecting other end extends into the speed reducer case 12 and is supported by a radial bearing 4a and a thrust bearing 4b provided inside the speed reducer case 12, and an intermediate portion is rotatably supported by the radial bearing 4c. A rotor 6 provided coaxially and integrally with the rotary shaft 5 and a commutator 13 provided coaxially and integrally with the rotary shaft. Two magnets 7 are provided as a plurality of magnetic poles fixed to the inner peripheral surface of the motor case 3 so as to face the outer peripheral surface. In addition, a pair of brushes 14 for driving the electric motor 1 by energization is provided inside the motor unit 2 so as to be in sliding contact with the commutator 13.

  A worm 5a is integrally provided at an intermediate portion between the radial bearings 4a and 4c extending in the speed reducer case 12 of the rotary shaft 5. A worm wheel 9 is gear-coupled to the worm 5a, and the speed reduction mechanism 4 is constituted by these worm gears. The central axis of the worm wheel 9 is configured as an output shaft 9a of the motor device, and a link mechanism as a power transmission mechanism for opening and closing a window glass (not shown) is connected to the output shaft 9a.

  The rotor 6 is provided integrally with the rotating shaft 5 and radially with respect to the rotating shaft 5, and includes a plurality of teeth 8 each including a flange portion 8 a projecting in the circumferential direction of the rotating shaft 5 at each tip portion thereof. A plurality of armature coils (not shown) wound around the teeth 8 are configured. Each terminal line of the plurality of armature coils is electrically connected to a desired position of the commutator 13 described above. The tooth 8 includes a tooth 8 having a wrinkleless portion 8b that does not have the flange portion 8a in some of the plurality of teeth 8. In the present embodiment, the wrinkleless portion 8b is provided at an intermediate portion in the axial direction of the rotating shaft 5 of the tooth 8, but may be provided at an end portion of the tooth 8 in the axial direction of the rotating shaft 5 or the like. Further, the tooth 8 of the rotor 5 in the present embodiment is provided with a skew angle with respect to the rotating shaft 5.

  As shown in FIG. 2, in this embodiment, the rotor 6 has, for example, ten teeth 8, and the angle between the teeth 8 is set to 36 °, and four of them have a wrinkleless portion 8b. Teeth 8 Two teeth 8 each having a wrinkleless portion 8 b are provided adjacent to each other at an angle of 72 °, and each adjacent set is provided symmetrically with respect to the rotation axis 5. The teeth 8 having the flange portions 8a are provided adjacent to each other at an angle of 108 °, and each adjacent set is provided symmetrically with respect to the rotation axis 5. FIG. 3 shows the rotor 6 (core) formed by the teeth 8 arranged in this way. When the size of the wrinkleless portion is illustrated, when the core diameter formed by the teeth 8 of the rotor 6 is 25 mm and the length in the axial direction of the core is 24 mm, the wrinkleless portion is the axial direction of the teeth 8. The middle part is formed with a size of 10 mm. Two magnets 7 are provided on the inner periphery of the motor case 3 to form two poles, and one magnet 7 has a polar arc angle (108 °) corresponding to three adjacent flanges.

  The rotary shaft 5 is pivotally supported by the motor case 3 and the speed reducer case 12, and both end portions in the axial direction are abutted and supported by the thrust bearings 3 b and 4 b by the steel balls 10 and 11. In addition, the bearing structure by the steel balls 10 and 11 may be a well-known one and may not be described in detail.

  The effect obtained by the above configuration will be described. By providing the teeth 8 with the flange 8a cut off as described above, the cogging torque at the rotational position of the rotor 6 changes as shown in FIG. FIG. 4 shows the cogging torque at the rotational position of the rotor between the electric motor 2 according to the present embodiment and the electric motor of the same configuration except for the absence of the wrinkleless portion 8b as compared with the present embodiment. . A cogging torque having a period corresponding to the number of slots is generated in a normal electric motor that does not have the wrinkleless portion 8b. On the other hand, since the electric motor 2 according to the present embodiment is provided with the wrinkleless portions 8b adjacent to the teeth 8 two by two, a large cogging torque change can be generated, and the rotational axis is symmetrical. Therefore, the cogging torque changes greatly at a cycle of 180 ° according to the number of poles (two poles).

  All of the teeth 8 having the six flange portions of the electric motor 2 in the present embodiment are opposed to the magnet 7, that is, the angle 108 ° between the adjacent three teeth having the flange portion 8 a and the polar arc angle of the magnet 7. At the initial position where (108 °) coincides, the cogging torque becomes 0, and when an external force is applied to the output shaft 9a from this position to rotate the rotor 6, a cogging torque in the direction opposite to the rotational direction is generated. . The cogging torque in the reverse direction is maximized when the rotor 6 is rotated 45 ° from the initial position, and then the cogging torque decreases as the rotation proceeds further, and becomes zero again at the position rotated 90 °. Thereafter, when the rotation is advanced, the cogging torque is generated in the direction in which the rotor 6 is rotated. The forward cogging torque becomes maximum at a position rotated 135 ° from the initial position, and then decreased to 0 at a position rotated 180 °. In this embodiment, since the arrangement of the teeth 8 is symmetrical at 180 °, the cogging torque similarly changes when rotating from 180 ° to 360 °, that is, the peak of the cogging torque is during one rotation of the rotor 6. Will occur twice.

  In the present embodiment, the anti-rotation force is, for example, a core diameter formed by the teeth 8 of the rotor 6 is 25 mm, the core length in the axial direction is 24 mm, and the wrinkle-free portion is 10 mm in the middle portion of the teeth in the axial direction. Is about 20 mN · m. This is about 3 to 10 times the anti-rotation force of the electric motor having all the normal flange portions 8a. When it is desired to increase or decrease the cogging torque, adjustment can be performed by changing the axial length of the wrinkleless portion 8b.

  In addition, when the brush 14 of the electric motor 2 is energized to rotate the electric motor 2, the force that prevents rotation and the force that promotes rotation are alternately generated with the same magnitude as described above. There is no reduction in efficiency.

  Further, the anti-rotation force using the cogging torque eliminates the need to generate a frictional force at the thrust bearing portion. Therefore, a steel ball having a simple and inexpensive structure can be adopted as the thrust bearing, and the manufacturing cost can be reduced. Further, since the frictional resistance generated from the thrust bearing is eliminated, the motor efficiency is improved.

  Further, there is a concern about the occurrence of vibration and noise by increasing the cogging torque, but only slight deterioration is confirmed in the low frequency component (around 200 Hz), and there is almost no influence on the sound pressure.

  Further, even if the teeth 8 are provided with a skew angle with respect to the rotation shaft 5, a cogging torque that can be used for preventing rotation can be obtained as shown in FIG. Generally, when a skew angle is provided, the cogging torque is reduced, but in this embodiment, a skew angle is provided to prevent harmonic loss and noise and vibration. When the skew angle is not provided, the harmonic loss increases, and a small wave noise is additionally generated in the waveform of the graph shown in FIG.

  Although the embodiment according to the present invention has been described above, various changes can be made in addition to the described embodiment. For example, in the present embodiment, a two-pole motor is used, but the number of poles can be arbitrarily selected as four or six poles, and the teeth of the teeth located at a position corresponding to the interval between the magnets are notched as in the embodiment. Thus, the cogging torque can be increased. Furthermore, although the two magnets 7 are used in the present embodiment, a ring-shaped magnet in which the magnetic poles are connected may be used.

It is sectional drawing which shows the power window drive device for motor vehicles using the motor and motor to which this invention was applied. It is sectional drawing which shows the power window apparatus for motor vehicles using the motor and motor which were seen from the arrow X direction in FIG. It is a perspective view which shows the teeth shape of the rotor of the motor which concerns on this embodiment. It is a figure which shows the waveform of a cogging torque.

Explanation of symbols

DESCRIPTION OF SYMBOLS 2 Motor part 3 Motor case 4 Deceleration mechanism 5 Rotating shaft 6 Rotor 7 Magnet 8 Teeth 8a Hail 8b Hailless part 9a Output shaft 10.11 Steel ball 12 Reduction gear case 13 Commutator 14 Brush

Claims (9)

A rotation axis;
A motor case that includes the rotating shaft and supports the rotating shaft;
An armature coil is wound around a plurality of teeth that are provided integrally with the rotating shaft and radially with respect to the rotating shaft, and each has a flange portion protruding in the circumferential direction of the rotating shaft. A rotor,
In order to form a plurality of magnetic poles on the inner peripheral surface of the motor case, a stator having a plurality of magnetic pole magnets disposed on the inner peripheral surface of the motor case so as to face the outer peripheral surface of the rotor. An electric motor,
Of the plurality of teeth positioned at positions facing each other between the magnetic poles in the circumferential direction of the magnet in a non-energized state of the electric motor, a tooth in which the flange portion is partially cut is provided with respect to the rotating shaft. An electric motor comprising a plurality of symmetrical motors.   2. The electric motor according to claim 1, wherein the teeth in which a part of the hook part is cut off have an intermediate part in the axial direction of the rotating shaft of the hook part cut out.   3. The electric motor according to claim 1, wherein both end surfaces of the rotating shaft in the axial direction are supported by the motor case via steel balls.   The electric motor according to claim 1, wherein the teeth have a skew angle and are provided integrally with a rotating shaft. A drive device for a vehicle opening / closing body that opens and closes the vehicle opening / closing body by an electric motor,
The drive device includes an electric motor, an output shaft that outputs the rotation of the electric motor, and a power transmission mechanism that transmits the rotation of the output shaft to the vehicle opening and closing body,
The electric motor is
A rotation axis;
A motor case that includes the rotating shaft and supports the rotating shaft;
An armature coil is wound around a plurality of teeth that are provided integrally with the rotating shaft and radially with respect to the rotating shaft, and each has a flange that protrudes in the circumferential direction of the rotating shaft. A rotor,
In order to form a plurality of magnetic poles on the inner peripheral surface of the motor case, a stator having a plurality of magnetic pole magnets disposed on the inner peripheral surface of the motor case so as to face the outer peripheral surface of the rotor. An electric motor,
Including a plurality of teeth in which the flange portion is partially cut out of the plurality of teeth in a range corresponding to the magnetic pole spacing in the circumferential direction of the magnet so as to be symmetric with respect to the rotation axis. A drive device for a vehicle opening / closing body.   The drive device for a vehicle opening / closing body according to claim 5, wherein the teeth in which a part of the collar part is cut off have an intermediate part in the axial direction cut away from the rotation shaft of the collar part.   The drive device for a vehicle opening / closing body according to claim 5 or 6, wherein both end surfaces of the rotating shaft in the axial direction are supported by the motor case via steel balls.   The drive device for a vehicle opening / closing body according to any one of claims 5 to 7, wherein the teeth have a skew angle and are provided integrally with a rotating shaft. The rotor has 10 teeth,
The magnet has two polar arc angles corresponding to three teeth continuous in the circumferential direction of the rotating shaft, and two magnets are disposed at positions symmetrical to the rotating shaft,
The four teeth out of the ten teeth in a range corresponding to the magnetic pole interval in the circumferential direction of the two magnets are teeth in which a part of the flange portion is cut off. The drive device for a vehicle opening / closing body according to any one of 5 to 8.

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