JP2010187512A - Motor damper, and motor using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To facilitate achieving a low-vibration motor. <P>SOLUTION: A damper 100a for a stepping motor includes a shaft 10 fixed to a motor shaft b of a stepping motor M, an annular inertial body 20 coaxially arranged outside the shaft 10, an elastic member 30a fixed between the shaft 10 and the inertial body 20. The elastic member 30a is composed of parts such as a cylindrical part 31a and an annular part 32a along the axial direction of the shaft 10. The hardness or the like of each rubber material used as the cylindrical part 31a and the annular part 32a is different from each other. As a result, it is also possible to suppress vibration in a low-speed region of ≤1 kHz. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a motor damper or the like for suppressing vibrations generated when various motors such as stepping motors are driven.

  Stepping motors are widely used because they can easily perform high-precision positioning, and are small in size and capable of obtaining high torque. In addition to this, there is a new demand for low vibration and low noise.

 In order to reduce the vibration of stepping motors, etc., it is indispensable to suppress resonance and instability phenomena (increased rotation unevenness, step-out, etc.) that appear when driving from low speed to high speed in a short time. There is a method in which a damper is used to absorb vibration (for example, Patent Documents 1 and 2, etc.).

  FIG. 10 is a cross-sectional view of a conventional stepping motor damper, and FIG. 11 is a rear view of the damper. In the figure, 1 is a damper for a stepping motor, 2 is a motor shaft of a stepping motor, 3 is a cylindrical flange portion fixed to the motor shaft 2, and 4 is an annular shape fixed to the outside of the flange portion 3 and using a rubber material The elastic member 5 is an annular inertia body having an outer shape equivalent to that of the elastic member 4. In the figure, 6 is a set screw for fixing the damper 1 to the motor shaft 2, 7 is a screw hole of the set screw 6 formed on the outer peripheral surface of the flange portion 3, and 8 is a motor shaft 2 formed on the flange portion 3. The through holes 9 are steel wires provided radially in the elastic member 4 at 45-degree pitch intervals.

  FIG. 12 shows the transient response characteristics of the stepping motor using the damper 1. During the step operation of the motor, the rotational force of the motor shaft 2 is transmitted to the inertial body 5 via the flange portion 3 and the elastic member 4. At this time, as shown in the figure, the motor shaft 2 tries to rotate due to the inertia of the inertial body 5 at the stop timing of the motor, but the rotation is limited by the elastic member 4, and then the motor shaft undergoes a damped vibration. Stops. The damping vibration of the motor is absorbed as the torsional force of the elastic member 4. Since the vibration of the motor is greatly influenced not only by the basic structure of the motor but also by the driver and load, it is necessary to use the optimal damper 1 to sufficiently suppress this. It becomes.

Japanese Examined Patent Publication No. 6-67173 JP 61-9156 A

  However, when the damper 1 is used in the stepping motor, the vibration of the motor is effectively partially absorbed, but it is very difficult to sufficiently suppress the vibration in the low speed region of about 1 kHz or less as shown in FIG. is there. Unless this problem is solved, it is difficult to develop a low-cost and low-vibration stepping motor that can sufficiently satisfy the user's demand. Moreover, although the frequency band which produces a vibration differs, the same problem is pointed out also about various motors other than a stepping motor, and it is difficult to achieve low vibration of a motor easily.

  The present invention has been created under the above-described background, and an object of the present invention is to provide a motor damper and the like that can easily reduce the vibration of the motor.

  In order to solve the above-described problems, a motor damper according to the present invention includes a shaft portion fixed to a motor shaft of a motor, an annular inertial body coaxially disposed on a radially outer side of the shaft portion, and a shaft portion. And an elastic member fixed between the inertial body and the inertial body, the elastic member is composed of a plurality of portions along the axial direction of the shaft portion, and at least the hardness of each of the plurality of portions is different from each other. Rubber material is used. The rubber material here refers to a substance that has the property of extending by an external force and returning almost instantaneously when the external force is removed. Examples thereof include butyl rubber, nitrile rubber, and chloroprene rubber.

  According to the present invention, the rotational force of the motor shaft is transmitted to the inertial body via the shaft portion and the elastic member during the step operation of the motor. At this time, even if the torque generated by the motor instantaneously becomes zero, the motor shaft rotates due to the inertia of the inertial body. However, the rotation is limited by the elastic member, and then the motor shaft stops through the damping vibration. The damping vibration of the motor is absorbed as a torsional force of a plurality of parts constituting the elastic member. In this respect, since the elastic member is made of rubber materials having different hardnesses at least for all or a part of the plurality of parts, the magnitude of the torsional moment acting on each part at the time of damped vibration is in each part. Depending on it. Therefore, if the hardness, dimensions, etc. of each part constituting the elastic member are changed, the degree of absorption of the frequency component contained in the damped vibration is effectively changed, and the motor can be easily reduced in vibration. Become. In particular, in the case of a stepping motor, it is possible to easily suppress vibrations in a low speed region of about 1 kHz or less, and accordingly, resonance and unstable phenomena (rotational unevenness) that appear when the motor is driven from a low speed to a high speed range. Increase or step-out) can be effectively suppressed.

  As a specific example of the elastic member in the damper, a cylindrical portion disposed between the outer peripheral surface of the shaft portion and the inner peripheral surface of the inertia body, and at least one end portion in the axial direction of the cylindrical portion are provided coaxially. There exists a thing of the structure which has an annular part which contact | abuts the axial direction surface of an inertia body as a collar part. In particular, the cylindrical portion may be composed of a plurality of annular bodies arranged in contact with each other in the axial direction.

According to the invention of this subordinate concept, since it is a simple configuration that is very easy to assemble, there is an advantage in reducing the cost.

  The motor of the present invention includes a motor body and the motor damper connected to the motor shaft of the motor body.

  According to the present invention, since the motor damper described above is used, it is possible to easily reduce the vibration of the motor. In particular, in the case of a stepping motor, it is possible to effectively suppress resonance and instability phenomenon (increase in rotation unevenness, step-out, etc.) that appear when driving from a low speed range to a high speed range. And reduction in vibration can be achieved.

  In the motor, it is preferable that the motor shaft of the motor main body is press-fitted and fixed in the hole of the shaft portion of the motor damper.

According to the invention of this subordinate concept, not only is it easy to fix the damper, but also the deviation of the center of gravity of the damper is unlikely to occur, and it is possible to further reduce the vibration of the motor.

1 is a schematic view of a stepping motor according to an embodiment of the present invention, and includes a cross-sectional view of a stepping motor damper. It is the front view and back view of the damper for stepping motors shown in FIG. It is a graph which shows the speed-vibration characteristic at the time of using the damper for stepping motors shown in FIG. It is sectional drawing of the damper for stepping motors which concerns on a 1st modification. It is a graph which shows the speed-vibration characteristic at the time of using the damper for stepping motors shown in FIG. It is sectional drawing of the damper for stepping motors concerning a 2nd modification. It is a graph which shows the speed-vibration characteristic at the time of using the damper for stepping motors shown in FIG. It is sectional drawing of the damper for stepping motors concerning a 3rd modification. It is a graph which shows the speed-vibration characteristic at the time of using the damper for stepping motors shown in FIG. It is sectional drawing of the damper for conventional stepping motors. It is a reverse view of the damper shown in FIG. It is a graph which shows the transient response characteristic of the damper shown in FIG. It is a graph which shows the speed-vibration characteristic of the damper for stepping motors shown in FIG.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 3 by taking a stepping motor as an example. In addition, for those in which the correspondence between the invention specific matters of the invention described in the claims and the constituent elements of the invention according to the embodiments of the specification is unclear, it will be combined in the column of the reference numerals of the invention described later. Shall be shown.

FIG. 1 is a schematic view of a stepping motor M, and also shows a cross-sectional view of a stepping motor damper 100a. 2A and 2B show a front view and a back view of the damper 100a, respectively.

  In FIG. 1, a is a motor body, b is a motor shaft, and 100a is a stepping motor damper. These constitute the stepping motor M. Further, in the figure, 10 is a flange portion fixed to the motor shaft b, 20 is an annular inertial body disposed coaxially on the radially outer side of the flange portion 10, and 30 a is between the flange portion 10 and the inertial body 20. It is an elastic member fixed to the. These parts constitute a stepping motor damper 1.

  The flange portion 10 is a metal pipe having a hole 11 formed in the axial direction at the center thereof. The motor shaft b is passed through the hole 11 of the flange portion 10 and is press-fitted and fixed.

  The inertia body 20 is a metal disk having a thickness about half that of the flange portion 10 and is fixed to the outside of the flange portion 10 via an elastic member 30a.

  The elastic member 30a is a shaft-like elastic body interposed between the flange portion 10 and the inertia body 20, and is disposed between the outer peripheral surface 12 of the flange portion 10 and the inner peripheral surface 21 of the inertia body 20. A cylindrical portion 31a, and a flange portion coaxially provided at one end portion 311a in the axial direction of the cylindrical portion 31a, and an annular portion 32a, most of which abuts against the axial surface 22 of the inertial body 20. It has become.

In the present embodiment, the length of the cylindrical portion 31 a is the same as the thickness of the inertial body 20, and the annular portion 32 a has a smaller diameter than the inertial body 20. Further, butyl rubber is used as the material of the cylindrical portion 31a and the annular portion 32a, the hardness of the cylindrical portion 31a is HS30, and the hardness of the annular portion 32a is HS50. For hardness, the hardness measurement method defined in JISK6253 (when a small contact force is applied to the surface of a rubber test piece through a sphere and then a larger indentation force is applied, the total is added. Measured based on the difference between the indentation depth of the ball by the indentation force and the indentation depth of the ball by the contact force). The same applies to the description of hardness described later.

  That is, the elastic member 30a is composed of a cylindrical portion 31a and an annular portion 32a along the axial direction of the flange portion 10, and the hardness of the rubber material used as the cylindrical portion 31a and the annular portion 32a is different from each other. Yes. The elastic member 30a may be integrally formed, or the cylindrical portion 31a and the annular portion 32a may be bonded with an adhesive or the like.

  FIG. 3 shows the speed-vibration characteristics when the stepping motor damper 100a constructed as described above is fixed to the motor shaft b of the stepping motor M and the motor is actually driven. The experimental conditions such as the motor, driver, and motor current when measuring the speed-vibration characteristics are exactly the same as those shown in FIG. This also applies to the graphs of FIGS. 5, 7, and 9 described later.

  As shown in FIG. 3, when the stepping motor damper 100a is used for the stepping motor M, it has been confirmed through experiments that the vibration level in the low speed region of about 1 kHz or less can be suppressed to about ３ compared to the conventional case. Yes.

  FIG. 4 is a sectional view of a stepping motor damper 100b according to a first modification. What differs from the stepper motor damper 100a shown in FIG. 1 is the material of the elastic deformable member 30b. That is, chloroprene rubber is used as the material of the cylindrical portion 31b, butyl rubber is used as the material of the annular portion 32b, the hardness of the cylindrical portion 31b is HS60, and the hardness of the annular portion 32b is HS50. Other configurations are the same as those of the stepping motor damper 100a.

  The speed-vibration characteristics when such a stepping motor damper 100b is used are as shown in FIG. It was confirmed that the peak of the vibration level in the low speed region of about 0.8 kHz or less was suppressed to a low level as compared with the case where the stepping motor damper 100a was used.

  FIG. 6 shows a sectional view of a stepping motor damper 100c according to a second modification. What differs from the stepping motor damper 100a shown in FIG. 1 is the material of the elastic member 30c. That is, butyl rubber is used as the material of the cylindrical portion 31c, and nitrile rubber is used as the material of the annular portion 32c. The hardness of the cylindrical portion 31c is HS30, and the hardness of the annular portion 32c is HS80. Further, most of the annular portion 32 c is in contact with the axially rear surface 23 of the inertial body 20. Other configurations are the same as those of the stepping motor damper 100a.

  The speed-vibration characteristics when such a stepping motor damper 100c is used are as shown in FIG. It was confirmed by experiments that the vibration level in the low speed region of about 1 kHz or less was suppressed to the same level as when the stepping motor damper 100a was used.

  FIG. 8 shows a cross-sectional view of a stepping motor damper 100d according to a third modification. What differs from the stepping motor damper 100a shown in FIG. 1 is the material of the elastic member 30d. That is, the cylindrical portion 31d is composed of annular bodies 311d and 312d arranged in contact with each other in the axial direction of the flange portion 10. The material of the annular body 311d is butyl rubber, and the material of the annular body 312d is chloroprene rubber. The hardness of the annular body 311d is HS30, and the hardness of the annular body 312d is HS60. The material of the annular portion 32d is nitrile rubber, and its hardness is HS80. Other configurations are the same as those of the stepping motor damper 100a.

  The speed-vibration characteristics when such a stepping motor damper 100d is used are as shown in FIG. It has been confirmed by experiments that the vibration level in the low speed region of about 1 kHz or less can be suppressed to approximately the same level as when the stepping motor damper 100a is used.

  From these experimental results, when the materials, hardness, dimensions, shape, etc. of the plurality of parts constituting the elastic members 30a-30d used in the stepper motor dampers 100a-100d are optimized through experiments, the range from the low speed range to the high speed range is obtained. Resonance and unstable phenomena (increase in rotation unevenness, step-out, etc.) appearing during driving can be suppressed in a short time, and the stepping motor M can be reduced in vibration. In addition, since the entire configuration of the damper is very simple and the optimization work is very easy as compared with the conventional one, the cost of the motor M can be reduced.

  The motor damper according to the present invention can be applied not only to the stepping motor but also to various motors such as a DC motor, an induction motor, a synchronous motor, and an ultrasonic motor. The basic shape may be used. The shape or the like of the shaft portion fixed to the motor shaft of the motor is not limited. For example, the shaft portion may have a shape provided with a flange or may not penetrate the motor shaft. Regarding the annular inertial body arranged coaxially on the outer side of the shaft in the radial direction, the required speed- What is necessary is just to adjust suitably according to a vibration characteristic. Further, the outside of the inertial body may be used as a pulley or a gear. About the elastic member fixed between the shaft portion and the inertial body, the rubber material is composed of a plurality of portions along the axial direction of the shaft portion, and the hardness is different from each other at least for all or a part of the plurality of portions. As long as is used, its shape, thickness, material, etc. are not questioned. For example, in the damper 1 shown in FIG. 10, the elastic member 4 is composed of a plurality of portions along the axial direction of the flange portion 3, and rubber materials having different hardnesses are used at least for all or a part of each portion. You may do it.

 The motor according to the present invention can be similarly applied to various motors such as a DC motor, an induction motor, a synchronous motor, and an ultrasonic motor as well as a stepping motor as long as the motor damper is provided. The fixing method between the motor shaft and the motor damper is not limited. For example, the motor shaft may be screwed to the motor shaft 2 as in the damper 1 shown in FIG. The positional relationship between the motor body and the motor damper is not limited. For example, a motor damper may be connected to a motor shaft located in the motor body. Further, the motor damper may be integrated with the rotor of the motor instead of being connected to the motor shaft.

M Stepping motor (motor)
a Motor body b Motor shaft 100 Stepper motor damper (motor damper)
10 Flange (shaft)
20 Inertial body 30 Elastic member 31 Cylindrical part 32 Annular part

Claims (5)

A shaft portion fixed to the motor shaft of the motor, an annular inertia body coaxially disposed on the outer side in the radial direction of the shaft portion, and an elastic member fixed between the shaft portion and the inertia body And the elastic member is composed of a plurality of portions along the axial direction of the shaft portion, and rubber materials having different hardnesses are used for all or a part of the plurality of portions. Motor damper. 2. The motor damper according to claim 1, wherein the elastic member includes a cylindrical portion disposed between an outer peripheral surface of the shaft portion and an inner peripheral surface of the inertia body, and at least one end portion in the axial direction of the cylindrical portion. And a ring-shaped portion that is a flange portion that is provided coaxially and abuts against an axial surface of the inertial body. 3. The motor damper according to claim 2, wherein the cylindrical portion is composed of a plurality of annular bodies arranged in contact with each other in the axial direction. A motor comprising: a motor body; and the motor damper according to claim 1, 2 or 3 connected to a motor shaft of the motor body. 5. The motor according to claim 4, wherein a motor shaft of the motor main body is press-fitted and fixed in a hole of a shaft portion of the motor damper.

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