JP2016127703A - Outer rotor motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an outer rotor motor which can easily rotate at a high speed and can correspond to a super low speed.SOLUTION: At least two pairs of deviation expansion mechanisms of a bending type with an expansion type piezo electric element as a driving source are oppositely arranged while sandwiching a rotational axis therebetween, and a stator outer periphery is elliptically driven by the deviation expansion mechanism. Therefore, an outer rotor motor can be provided that increases a transmission amount that a stator side gear provided in the stator outer periphery transmits a rotor side gear provided in a rotor inner periphery to a rotational direction, and can easily correspond from a super low speed to a high speed.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an outer rotor motor using a drive source that expands and contracts in a direction orthogonal to a rotation axis.

  At present, a piezoelectric motor using an elastic member typified by a piezoelectric element is widely used as an actuator for fine processing and a fine driving device. Among such motors, Japanese Patent Application Laid-Open Nos. 61-177178 (hereinafter referred to as Patent Document 1) and Japanese Patent Publication No. 06-048910 (hereinafter referred to as Patent Document 2) have been published and registered, respectively, as typical structures. Yes.

  Of these two cases, the structure described in Patent Document 1 has a technical feature in that a displacement is output by bending a piezoelectric element that expands and contracts, and a gear on the rotor side is sequentially fed. A stepping motor using three piezoelectric elements is disclosed. In addition, the structure described in Patent Document 2 has a stator in which three or more piezoelectric elements are arranged circumferentially inscribed in the rotor, and each piezoelectric element has a frequency equal to 1 / N of the period in the circumferential direction. The technical feature is to supply a sinusoidal voltage having a phase difference, and it is possible to provide a motor that can easily obtain a low-speed and high-torque rotational force based on the technical feature.

JP 61-177178 A JP 06-048910

  While having the above-described technical features and the effects thereof, the structure described in Patent Document 1 is premised on step driving using gears. For this reason, devices that require continuous high-precision driving such as one turn per day, such as a turntable used for microfabrication and a camera head used for astronomical observation, can be handled by intermittent rotation. There must be. Further, in the structure described in Patent Document 2, the expansion and contraction of the piezoelectric element is used as a drive source as it is, and when the number of rotations is increased, the piezoelectric element breaks down in the vicinity of the natural frequency of the piezoelectric element that is the drive source. Have.

  In order to solve the above-mentioned problems, the invention described in the present application aims to provide an outer rotor motor that is easy to rotate at high speed and can cope with ultra-low speed rotation.

  For the above-mentioned purpose, the invention described in the first aspect of the present invention is a displacement enlarging mechanism that is paired with two or more pairs of displacement enlarging mechanisms in which both ends of the piezoelectric element are connected by two output members. The feature is that they are arranged opposite each other. More specifically, the technical feature is that a stator for an outer rotor is configured by disposing the displacement enlarging mechanism so as to face the rotating shaft.

The invention described in the second aspect of the present invention is characterized in that the stator described in the first aspect is laminated in the direction of the rotation axis.

  Due to the technical features described above, the invention described in the first aspect of the present invention can provide an outer rotor motor that is easy to rotate at high speed while supporting ultra-low speed rotation. This is due to the fact that, with regard to the two pairs of displacement magnifying mechanisms, the pair of displacement magnifying mechanisms are arranged to face each other and the stator is configured.

  That is, in the structure described in this aspect, the piezoelectric element arranged in the direction orthogonal to the rotation axis is used as a drive source, and the rotor is rotated after the displacement is passed through the displacement magnifying mechanism. For this reason, the rotor can be driven by continuously inputting a signal to the piezoelectric element during the ultra-low speed rotation. In addition, when the rotor rotates at high speed, it is possible to increase the rotation speed while suppressing the increase of the input frequency to the piezoelectric element by causing the enlargement mechanism to function. Further, by using the stator configuration for the outer rotor motor, it is possible to secure the length of the piezoelectric element serving as the drive source and to obtain the effect of saving the space of the stator serving as the drive source.

  In addition, by using the above-described structure, the motor described in this aspect can incorporate a minimum of four displacement magnifying mechanisms on the same plane in the stator and rotate the rotor as a one-stage configuration. This is an effect obtained by using the displacement enlarging mechanism for the outer rotor motor. That is, in the outer rotor motor described in this aspect, a displacement enlarging mechanism arranged orthogonal to the axis is used as a drive source, and the outer rotor is sent in the rotation direction by the elliptical motion of the stator using the displacement enlarging mechanism to rotate. Drive. For this reason, in the structure described in this aspect, it is possible to reduce the size of the stator mounted in the rotor while setting the lengths of the actuator and the piezoelectric element mounted in the rotor large. Further, since the output torque is proportional to the outer diameter of the rotor, the torque can be easily increased as compared with an inner rotor motor of the same size. In addition, by using the one-stage configuration, an overall thin configuration is also possible.

  Furthermore, by using a stator structure on which a minimum of four displacement magnifying mechanisms are mounted, the motor described in this aspect can be driven stably and without interruption even when driven at the ultra-low speed. That is, the stator used in this aspect expands the displacement of the piezoelectric element serving as a driving source by the resultant force obtained by reversing the bending direction of the output member constituting the displacement enlarging mechanism, and performs the feeding operation by the elliptical motion. Is going. For this reason, in the motor according to this aspect, the displacement amount of the output member can be given a margin, and the rotational drive can be performed with a stable torque and displacement.

  Moreover, in the structure described in this aspect, the structure is a rotor, a stator, and an enlarging mechanism from the outside, and a structure in which main structures other than the rotor shaft are not disposed in the central portion. For this reason, it becomes possible to respond | correspond to a wide usage form, such as mounting to a fixed shaft and a movable shaft, by comprising the whole outer rotor motor hollow.

  In addition to the effects described above, in the invention described in the second aspect of the present invention, the outer rotor motor described in the first aspect can be improved in versatility as a rotational drive source. Yes. That is, by stacking the stator according to the first aspect using the hollow structure or the like, an actuator provided with a plurality of rotors on the same rotating shaft can be formed. Thereby, it is possible not only to simply add torque as the outer rotor motor but also to give a different rotational speed to each rotor corresponding to each stator.

As described above, by using the structure described in the present invention, it is possible to provide an outer rotor motor that is easy to rotate at high speed and that can handle ultra-low speed rotation.

The perspective view of the outer rotor motor used in the best mode of the present invention 1 is a side sectional view taken along the line A-A 'shown in FIG. 1 is an exploded perspective view of the outer rotor motor shown in FIG. Drive unit explanatory diagram of the outer rotor motor shown in FIG.

  Hereinafter, the best embodiment of the present invention will be described with reference to FIGS. 1, 2, 3 and 4. In addition, about the symbol and component number in a figure, the common symbol or number is provided to what functions as the same component.

  FIG. 1 is a perspective view of an outer rotor motor used in this embodiment, FIG. 2 is a side sectional view taken along the line AA ′ in FIG. 1, and FIG. 3 is an exploded perspective view of the outer rotor motor shown in FIG. FIG. 4 and FIG. 4 are diagrams for explaining the drive section of the outer rotor motor. In addition, about the wiring and the drive circuit, description in a figure is abbreviate | omitted.

  As can be seen from FIGS. 1, 2, and 3, in this embodiment, two pairs of piezoelectric elements 3 and a displacement magnifying mechanism v are provided on the stator 2 provided with the stator side gear s on the outer periphery. A rotor side gear r that partially meshes with the stator side gear s is formed on the inner periphery of the rotor 4, and the stator and the rotor are supported by the base 5 via the spacer 6 and the bearing 8. Yes. In addition, the number of teeth is a structure in which the number of teeth of the stator side gear s is reduced by one than that of the rotor side gear r.

  In addition to the components described above, as can be seen from FIGS. 3 and 4, the present embodiment uses a structure in which two pairs of displacement magnifying mechanisms v arranged orthogonal to the rotation axis o are integrally formed with the stator 2. Therefore, it is possible to reduce the size of the stator 2 while ensuring the lengths of the displacement enlarging mechanism v and the piezoelectric element 3 mounted on the stator 2. In addition, since the stator 2 has a one-stage configuration, an overall thinning effect can be obtained.

  Further, as described above, the motor 1 described in the present embodiment has two pairs of the displacement enlarging mechanism v in which both ends of the piezoelectric element 3 are connected by the two output members p, and the stator 2 having the gear s formed on the outer periphery. It has a provided structure. As a result, the motor described in the present embodiment can be easily driven at a high speed while corresponding to an ultra-low speed such as one rotation per day.

  That is, as can be seen from FIG. 4, during the ultra-low speed rotation, the motor 1 described in the present embodiment moves the stator side gear s in an elliptical shape by the displacement magnifying mechanism v and sequentially sends the rotor side gear r in the rotational direction. Rotation drive is generated. More specifically, the rotation drive is performed by continuously inputting a signal to the piezoelectric element 3 and shifting the stator side gear s by one tooth per circumference to perform the feeding operation of the rotor side gear r. Yes. For this reason, as compared with a conventional motor using a piezoelectric element as a direct drive source, the feed amount of the rotor-side gear r is increased, and rotation drive at a wide speed is possible. Note that, due to the rotational drive, in the motor 1 described in the present embodiment, the stator side gear s and the rotor side gear r are always in partial contact. For this reason, by adjusting the initial position, the rotor 4 can be fixed even when no power is supplied.

  In addition, because of the structure of the stator 2 described in the present embodiment, the direction of bending caused by the two displacement magnifying mechanisms sandwiching the rotation axis o is reversed for the output member p constituting the displacement magnifying mechanism v in the stator. The feeding operation is performed using the resultant force. For this reason, by using the motor described in the present embodiment, even when driving at the ultra-low speed, it is possible to provide a sufficient amount of displacement of the displacement enlarging mechanism and to perform rotational driving with stable torque and displacement. Further, regarding the feed operation of the stator 2, the operation of the displacement magnifying mechanism v alone provided in the stator 2 is balanced with the movement of applying a voltage to the piezoelectric element 3 and extending the output member p and the output of the piezoelectric element 3. The movement of the output member p is restored by the restoring force acting on the displacement enlarging mechanism v. For this reason, the stator 2 can output a continuous operation in its structure. Due to these effects, the motor 1 described in the present embodiment can provide a stable rotational drive that is not interrupted when driven at the ultra-low speed.

  Further, in the case of driving at the high speed rotation, in the present embodiment, by using the enlargement mechanism v, it is possible to increase the rotation speed while suppressing the increase of the signal frequency input to the piezoelectric element 3. This is due to an increase in the amount of feed that can be transmitted from the stator 2 to the rotor 4 for each expansion / contraction by the displacement enlarging mechanism v. That is, in a motor using a telescopic member such as a piezoelectric element as a drive source, when the displacement of the telescopic member is used for a direct feed operation in the rotational direction, the upper limit of the feed rate is determined by the natural frequency of the telescopic member. On the other hand, since the motor 1 of the present embodiment performs a feed operation in the rotational direction via the displacement enlarging mechanism v, it is possible to set the upper limit of the feed speed high while using the same drive source. ing. In the present embodiment, a structure is used in which the number of teeth of the stator side gear s is reduced by one than that of the rotor side gear r. However, the feed rate can also be increased by increasing the difference in the number of teeth.

  In addition to the effects of the basic structure described above, the present embodiment uses a structure in which the stator 2 and the displacement enlarging mechanism v are integrally formed. For this reason, it is possible to suppress the concentration of stress during driving, and to perform the above-described transfer driving with high durability. Moreover, it is the structure of the rotor 4, the stator 2, the piezoelectric element 3, and the expansion mechanism v from the outside, and has a hollow structure in which main structures other than the rotor shaft h are not arranged in the central portion. For this reason, it is possible to deal with a wide range of usage forms such as mounting on a fixed shaft and a movable shaft, and it is also possible to easily give an effect of multi-function by the multi-stage of the stator 2.

As described above, by using the structure described in this embodiment, it has been possible to provide an outer rotor motor that is easy to rotate at high speed and can handle ultra-low speed rotation.

DESCRIPTION OF SYMBOLS 1 Outer rotor motor 2 Stator 3 Piezoelectric element 4 Rotor 5 Base 6 Spacer 7 Bearing 8 Stopper r Rotor side gear s Stator side gear v Displacement expansion mechanism p Output member h Rotor shaft o Rotating shaft

Claims (2)

An outer rotor motor using a piezoelectric element that expands and contracts in a direction perpendicular to the rotation axis as a drive source,
Two or more displacement magnifying mechanisms in which both ends of the piezoelectric element are connected by two output members,
The outer rotor motor which has a stator which the output member of the displacement expansion mechanism used as each pair opposes across the said rotating shaft.   An outer rotor motor in which a plurality of the stators are stacked in the rotation axis direction.

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