JPH0538171A - Ultrasonic motor with built-in reduction mechanism - Google Patents

Abstract

PURPOSE:To present a reduction gear for enabling great torque and low-speed rotation to be obtained by using the containing space of a rotary drum practically without changing the dimension of an ultrasonic wave motor. CONSTITUTION:On an ultrasonic wave motor with a rotary drum 3 circumscribed by a driving module 1, in the containing space section of the rotary drum 3, a plurality of rollers 4 are arranged, and a planetary mechanism is formed in a frictionally driving type so that the planetary motion of the rollers 4 may be performed, and the driving of the rotary drum 3 is retarded via the planetary mechanism, and the output is generated. In other words, the space of the rotary drum 3 is practically used, and a reduction gear is built in, and without changing the dimension, greater torque and low-speed rotation are to be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic motor in which a drive module is externally attached to a rotary drum to obtain rotary drive.

[0002]

2. Description of the Related Art FIG. 4 shows an example of a conventional ultrasonic motor in which a drive module is circumscribed on a rotary drum to obtain rotary drive. FIG. 4 is a front view of a main part of an example of a conventional ultrasonic motor, and FIG. 5 is a cross-sectional view taken along the arrow Woo of FIG. 4, in which a drive module 1 ″ integrally constructed by using a piezoelectric element or the like is used as a rotary drum. It is circumscribed on the outer diameter of 13 and is attached to the case with mounting bracket 2 '.
It is elastically attached to 14, with the required pressure on the circumscribed part,
An ultrasonic motor is configured by integrally supporting the rotary shaft 13a and a shaft 13a which are integrated with the rotary drum 13 and supporting them. To explain the driving action of the ultrasonic motor configured in this way, if a pulsed power supply is supplied to the drive module 1 ″ to the left (for left in FIG. 5) as the required rotation direction, for example, to obtain left rotation. Lower surface of the pressing contact of the drive module 1 ″ (A ′ in FIG. 5)
A right-handed elliptical wave motion is synthesized (not shown) in the section), and the rotary drum 13 pressed against this surface rotates by transmitting the wave motion by friction drive. Of course, in the case of clockwise rotation, the left power source may be turned off and the right power source may be supplied.

[0003]

However, in the above structure, the wave force and speed of the circumscribing surface of the drive module 1 "are determined by the size of the drive module 1", and this size is set to a practical size. Once determined, the output torque rotation speed of the shaft 13a is determined by the outer diameter of the rotating drum 13 which is in contact with the outside. That is, if the diameter is made extremely large, high torque can be obtained at low speed, but the size becomes larger than that of an ordinary electric motor equipped with a speed reducer, and even if the low speed and high torque characteristic of an ultrasonic motor can be obtained, Mass and size increase. On the contrary, if the diameter is made smaller, it becomes more compact, but since only extremely small torque can be obtained at high speed, the required output for high torque and low speed rotation of, for example, robots and FA equipment cannot be obtained, which is extremely problematic in practical use. Has become. The present invention has been made in view of the above-mentioned points, and an object of the present invention is to reduce the size without changing the size by utilizing the internal space (dead space) of the conventional rotary drum 13 and to reduce the speed. The torque and low-speed rotation are obtained, and at the same time, the drive system 2 directly connected to the rotary drum 13
The present invention provides an ultrasonic motor with a built-in reduction mechanism that can obtain various types of output.

[0004]

[Means for Solving the Problems] That is, the means for achieving the purpose are a. In the ultrasonic motor according to claim 1, wherein a drive module is circumscribed on the rotary drum to drive the rotation, three or more rollers are arranged on the circular surface in the internal space of the rotary drum, and the rollers are rigid in the rotational direction. , Which has an elastic function in the radial direction, builds a planetary reduction mechanism by friction drive so that it has a planetary motion, outputs the drive of the rotating drum through this planetary reduction unit, and detects rotation at the tip of this output shaft. Even if slippage occurs in the friction drive system by providing it, by performing correction drive with this,
Easily solve slip position deviation. However, since these planetary mechanisms utilize the space of the rotating drum, the planetary deceleration can be reduced without changing the size of the ultrasonic motor.
The torque is increased and low speed rotation is obtained, which solves the conventional problems. In addition, to increase convenience, one output shaft outputs decelerated high torque, and the other shaft outputs the conventional output drive in which the drive of the rotary drum is directly connected so that two types of output can be obtained. I have to.

B. In Claim 2, the roller that is planetary-moved by frictional drive in the mechanism of Claim 1 is rigid in the rotational direction and has an elastic function in the radial direction. -Shaped multiple grooves (in the shape of a ring) are inserted, the extra thickness between these grooves is formed into an ultra-thin disc spring shape to have the required elastic hardness, and the planetary mechanism is located above and below this roller. The inner and outer rings are arranged, and the elastic function is used to apply a pressing force to the inner and outer rings to form a friction drive system.

[0006]

The operation will be described together with the following embodiment. An embodiment of the ultrasonic motor of the present invention will be described below in detail with reference to the drawings.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (a) In claim 1, FIG. 1 is a front view of an essential part showing an embodiment of the present invention, and FIG.
2 is a sectional side view of the rotary drum 3 in FIG. 1 and 2 with an axis, one end of which is an output shaft (3b).
And the shaft at the other end is included within the width of the rotating drum 3, and the roller 4 is rigid to the outer diameter (FIG. 1d) of the roll shaft 3a in the rotating direction and elastic in the circular direction. Are arranged in three or more equal parts on the circular surface and pressed against each other, and the roller 4 is rotatably supported by a roller shaft 5 and attached to an arm 6 to be integrated with each other. The fixing ring 8 is inscribed (FIG. 1D). By this, the roller 4 is made to perform a planetary movement about the center of the arm 6 by friction drive,
A shaft 7 is attached to this arm 6, and this is output to the outside as the output shaft 7 (left side in FIG. 1) at the other end and is rotatably supported by the case 11. The fitting shaft 7a on the other side is the center of the roller shaft 5 described above. It is integrally attached to a rotary shaft. The required reduction ratio is obtained from the ratio (d / D) of the diameter of the roller shaft 3a of the rotary drum 3 (Fig. 1d) to the inscribed diameter of the fixed ring (Fig. 1D).
Further, a detection plate 9 is attached to the output shaft 7 (left side in FIG. 1) at the other end, and a rotation detector 10 is provided on the detection plate 9 to integrally configure them, and the drive module 1 rotationally drives one shaft (right side in FIG. 1). It is configured so that two types of rotation outputs can be obtained by directly connecting to and outputting to the shaft 7, and the other end of the shaft 7 to output decelerated rotation by friction drive of the planetary mechanism. In the present embodiment, the drive module 1 using the piezoelectric element is circumscribed to the rotary drum 3, but the present invention is not limited to this drive module, and other motors driven at the circumscribed portion of the rotary drum 3, such as an electric motor,
It goes without saying that any of the air motors, the water pressure motors, and the like can be applied as long as the internal portion of the rotary drum 3 has a space.

(B) Regarding Claim 2, FIG. 3 is a front view of a main portion of another embodiment of the present invention. The planetary-moving roller 4 is rigid in the rotational direction and elastic in the radial direction. A cylindrical roller 12 is provided as a means for this.
A plurality of conical grooves (ring-shaped) are inserted in the groove, the extra thickness between the grooves is formed into an extremely thin disc spring shape, and a plurality of elastic conical plates 12a having the required elastic hardness are integrally constructed. . This is attached to the roller shaft 5 ', the fixing ring 8'and the inner and outer diameters of the roll shaft 3' (Fig. 1D, d) are pressed against the upper and lower diameter portions of the roller 12, and the inner space of the rotating drum 3'is The planetary mechanism is built in the section and these are integrated into an ultrasonic motor with a built-in reduction mechanism.
The drive operation of the ultrasonic motor with a built-in speed reduction mechanism configured as described above will be described.

(A) Claim 1 When the driving module 1 is rotated counterclockwise as a required rotation direction, for example, when a pulsed power source is supplied to the left side (FIG. 2 left side), the pressing contact lower surface of the driving module 1 ( (Figure 2A part)
The right-handed elliptical wave motion is rigidized (not shown), and the rotary drum 3 pressed against this surface is rotated by frictional drive of the wave motion. Then, the roll shaft 3a integrated with the rotary drum 3 also rotates at the same time, and the roller 4 pressed against this also rotates due to the pressing frictional force. At this time, since the other diameter portion of the roller 4 is inscribed in the fixed ring 8, the frictional force causes the roller 4 to rotate while rotating at the inscribed diameter D portion. Ie roller 4
Makes a planetary motion. Then, the roller shaft 5, which is the support shaft of the roller 4, rotates about the center of the arm 6 with a reduction ratio of d / D. Since the arm 6 and the shaft 7 are integrated, the output decelerated by the planetary mechanism can be obtained. The output shaft 3b (right in FIG. 1) directly connected to the rotary drum 3 at the same time (left in FIG. 1) is, of course, obtained as the drive output of the rotary drum 3. That is, two types of drive can be obtained by the left and right output shafts 7 and 3b. Further, even if a slip occurs in the friction drive system, the slip detection against the input is immediately detected by the rotation detection units 9 and 10, and the correction control is performed accordingly, so that the drive accuracy can be easily and surely obtained, and the slip of the friction is not a problem. Not.

(B) According to the second aspect, the roller 4 which is planetary-moving is rigid in the rotating direction and elastic cone plate 12a as the roller 12 having an elastic function in the radial direction.
The inner diameter D'of the fixing ring 8'is constructed from multiple
And the outer diameter d'of the roll shaft 3'a, the outer diameter is made larger than the distance by a required amount so that a required pressing force can be obtained at the distance between the inner diameter and the outer diameter. A desired frictional force is obtained simply by inserting and incorporating the roller 12 in the portions D and d, and the drive of the rotary drum 3'is decelerated while performing planetary movement by frictional drive and transmitted to the output shaft 7 '. Further, by disposing the roller 12 at three or more locations on the circular surface, the pressing force of the roller 12 and the inner and outer diameters d and D cancel each other out as an internal force, and each shaft, 7 ', 7'a, 3 The pressing force does not act on the shaft supporting portions such as ′ b and the case 11, and efficient and balanced driving is performed.

[0011]

As described above, according to the present invention, by utilizing the internal space (dead space) of the conventional rotary drum 13, large decelerated torque and low speed rotation can be obtained without changing the size. At the same time, two types of outputs of the drive system directly connected to the rotary drum 13 can be obtained. Moreover,
Rotation detection on output side even if slippage occurs in friction drive system 9.10
Since you can immediately perform correction control with
Since it is a friction drive, high rigidity can be obtained, and extremely accurate drive can be obtained that can solve all the problems such as the backlash of gears and the delay of the transmission system due to the weak rigidity of the teeth. It is considered that when the diameter of the rotary drum 13 is reduced, the dead space is eliminated, but when the diameter is reduced (assuming that the tangential force of the drive module 1 ″ is constant), its drive output is low torque and high rotation. Therefore, it cannot be actually used for robots, FA, etc. that require high torque and low rotation. It is also possible to dispose the drive module 1 ″ inside the rotary drum 13, but in this case The strong surface pressure acts on both ends of the drive module 1 ″ due to the curvature of the drive module, and smooth drive characteristics cannot be obtained, which is also a difficult mechanism in practice. It will be arranged on the outer diameter portion of 13. In this case, according to the present invention, a stronger driving torque and a lower rotation can be obtained, and the invention can be widely used for ultra-precision positioning and the like, which is an extremely useful invention.

[0012]

[Brief description of drawings]

FIG. 1 is a front view of a main part showing an embodiment of an ultrasonic motor with a built-in reduction gear mechanism of the present invention according to claim 1.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a front view of an essential part showing an embodiment of the present invention according to claim 2;

FIG. 4 is a front view of a main part of an example of a conventional ultrasonic motor.

FIG. 5 is a sectional view taken in the direction of arrow W-U.

[0013]

[Explanation of symbols]

1 Drive module 2 Mounting hardware 3 rotating drums 4 roller 5 roller shaft 6 arms 7 axes 8 fixing ring 9 Detection plate 10 rotation detector 11 cases 12 roller 13 rotating drum 14 cases 1'drive module 2'mounting bracket 3'rotary drum 5'roller shaft 6'arm 7'axis 8'fixing ring 9'detection plate 10 'rotation detector 11 ′ case 1 ″ drive module 3a roll axis 3b axis 7a Lathe shaft 12a Elastic conical plate 13a axis 3′a roll axis 3′b axis 7'a ladle shaft

Claims (2)

[Claims] 1. An ultrasonic motor for rotatively driving a rotary drum by circumscribing a drive module, wherein a shaft is attached to the rotary drum, one end of which is output to the outside, and the other end of the rotary drum has the width of the rotary drum. A roller having rigidity in the direction of rotation and an elastic function in the direction of the diameter of the roll shaft is housed inside the roller shaft and equally pressed at three or more locations on the circular surface to press the roller. It is rotatably supported by a shaft, attached to an arm and integrated, and a fixing ring is inscribed on the outer diameter of each roller, so that the roller frictionally drives the center of the arm as a planet. This arm is equipped with a shaft, which is output to the outside as the output shaft of the other end, and the case has a planetary speed reduction mechanism that rotatably supports it by friction drive in the internal part of the rotary drum. Ratio is the shaft diameter of the other end of the rotating drum To the inscribed diameter of the fixing ring (d /
D), a rotation detector is provided on the output shaft at the other end, and these are integrally configured, and the rotary drive from the drive module is directly connected to one shaft for output, and is output to the other end shaft. Is an ultrasonic motor with a built-in speed reduction mechanism, which is configured to obtain two types of rotation output for outputting decelerated rotation by friction drive of the planetary mechanism. 2. The planetary roller is rigid in the rotation direction and has an elastic function in the radial direction. As a means for this, a cylindrical roller is provided with a plurality of conical ring-shaped grooves, The extra thickness between the grooves is formed in the shape of an extremely thin disc spring, and a plurality of elastic conical plates having the required elastic hardness are integrally constructed and attached to a roller shaft to be integrally configured. The ultrasonic motor with a built-in reduction mechanism according to claim 1.