JPH05122959A - Ultrasonic motor with built-in speed increase mechanism - Google Patents

Abstract

PURPOSE:To obtain increased-speed great-rotation without changing the size of an ultrasonic motor, making the most use of the space that a rotary drum contains. CONSTITUTION:In an ultrasonic motor where a driving module is circumscribed about the rotary drum, a plurality of rollers 4 are arranged at the space part that the rotary drum contains, and these rollers 4 are pressed to contact with the inside of the rotary drum and the outside of the output shaft so as to constitute a speed increase friction driving mechanism, and the driving of the rotary drum is output through this speed increase friction mechanism.

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 Conventionally, an example of an ultrasonic motor for externally rotating a rotary drum by providing a driving module on the rotary drum is shown in FIG. FIG. 3 is a front view of a main part of an example of a conventional ultrasonic motor, and FIG. 4 is a sectional view taken along the line EE of FIG. A shaft 8a which is circumscribed from the outer diameter portion of 8 and which is integrated with the rotary drum 8 is rotatably supported, and these are integrally constructed to form an ultrasonic motor. The driving operation of the ultrasonic motor configured as described above will be described. When the driving module 1 ′ is rotated counterclockwise, for example, when left rotation is obtained, power is supplied to the left (for left in FIG. 4) pulsed power source for driving. A clockwise elliptic wave is synthesized (not shown) on the lower surface of the pressing contact (A 'in FIG. 4) of the module 1', and the rotary drum 8 pressed against this surface frictionally drives the wave motion. To transmit and rotate. 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 and the number of rotations of the shaft 8a are determined by the outer diameter of the rotating drum 8 which is circumscribed. That is, if the diameter is made extremely large, high torque can be obtained, but the number of revolutions becomes extremely small, and the required number of revolutions cannot be obtained. On the contrary, if the diameter is made extremely small, high-speed rotation can be obtained, but the torque becomes extremely small. To increase the torque, the number of drive modules 1'can be increased, but since the diameter is small, the number of installations also decreases. After all, high torque cannot be obtained even if high rotation drive is obtained, and it cannot be applied to a drive source requiring high speed and high torque, such as a physical distribution carrier and labor-saving equipment, which is extremely problematic in practical use. ing. The present invention was devised in view of the above-mentioned points, and the purpose thereof is to increase the speed without changing the size by utilizing the internal space (dead space) of the conventional rotary drum 8. High speed rotation and high torque are obtained,
At the same time, the present invention provides an ultrasonic motor with a built-in speed increasing mechanism that can obtain two types of outputs of a drive system directly connected to the rotary drum 8.

[0004]

[Means for Solving the Problems] In other words, the means for achieving the object is an ultrasonic motor for rotatably driving a rotary drum by circumscribing a driving module on the rotary drum. At least three or more rollers are arranged. This roller is rigid in the rotating direction and has an elastic function in the radial direction. Furthermore, the roller shaft is arranged on the outer diameter portion of the roller to press and contact each roller. The friction is transmitted on the surface, the speed-up friction drive mechanism by the roller is constructed, and the drive of the rotary drum is output through this speed-up friction drive system. Thus, since these speed-up friction drive mechanisms utilize the space of the rotary drum, the speed is increased by the speed increase without changing the size of the ultrasonic motor, and the decrease in torque due to the speed increase is reduced by the drive module. By adding and compensating to obtain high speed and high torque, the conventional problems have been solved. In order to increase convenience, one shaft outputs this increased high-speed rotation, and the other output shaft performs the conventional output drive that is directly connected to the drive of the rotary drum. I am trying to get it.

[0005]

The operation will be described in detail in conjunction with the embodiment described below.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a front view of an essential part showing an embodiment of the present invention,
FIG. 2 is a side view of a cross section taken along the arrow line in FIG. 1, and in FIGS. 1 and 2, the rotary drum 3 is provided with a shaft 3b, and
As one of them, the roller 4 is put out to the outside (on the right side) and is contained in the inner ring 3a of the rotating drum 3 so that the roller 4 is equally pressed at three or more points on the circular surface, and the roller 4 is pressed in the radial direction. Has the function of elastically expanding and contracting and becoming rigid in the direction of rotation.
Is rotatably supported by a roller shaft 5, and a roll shaft 6a is further arranged on the outer diameter portion of the roller 4 and pressed against it, and one end of this roll shaft 6a is taken out as the output shaft 6 to the other (left side). A roll shaft 6b is attached to the other end, and this is rotatably supported on the shaft 3b of the rotary drum 3.
It is constructed integrally with Case 7.

Thus, the rotational drive from the rotary drum 3 is
A drive system for transmitting friction to the rollers 4 and the roll shaft 6a is constituted, and the speed increasing ratio is determined by the ratio (D / d) of the diameter D of the inner ring 3a of the rotating drum 3 and the diameter d of the roll shaft 3a. can get. That is, two types of rotation outputs are obtained, in which the rotation drive from the drive module 1 is directly connected to one shaft 3b (right side) and output, and the other side shaft 6 outputs increased rotation by friction transmission drive. And an ultrasonic motor with a built-in speed increasing mechanism. In this embodiment, the drive module 1 using the piezoelectric element is circumscribed on the rotary drum 3. However, the drive module 1 is not limited to this drive module, and other motors driven by the circumscribed portion of the rotary drum 3, for example, an electric motor. It goes without saying that any of the air drums, the water pressure motors, and the like, which have a space inside the rotary drum 3, can be applied. The driving operation of the ultrasonic motor with the speed increasing mechanism thus configured will be described.

When the drive module 1 is rotated counterclockwise as a required rotation direction, for example, by supplying a pulse-shaped power source to the left (left in FIG. 2), the right side of the lower pressing surface (portion A in FIG. 2) of the drive module 1 is rotated. The rotating drum 3 which is composed of the undulating elliptical motion (not shown) and presses against this surface.
Rotates by transmitting the wave motion by friction drive. The roller 4 pressed against the inner ring 3a that is integral with the rotary drum 3 also rotates due to the pressing frictional force. At this time,
Since the roller 4 is rotatably supported by the roller shaft 5,
Rotate in that position. Then, the roll shaft 6a pressed against the outer diameter portion of the roller 4 also rotates due to the pressing frictional force. That is, the rotational drive of the rotary drum 3 is output to the one shaft 6 (left side) via the roll shaft 6a with the speed increasing ratio (D / d) by the speed increasing friction drive mechanism. At the same time, the rotating drum 3
As a matter of course, the output shaft 3b directly connected to (the right side in FIG. 1) can be obtained as it is as the drive output of the rotary drum 3. That is, two types of drive can be obtained with the left and right output shafts 6, 3b. Further, by arranging the rollers 4 at three or more locations on the circular surface, the pressing force of the rollers required for friction transmission drive is canceled out as an internal force in each of the inner ring 3a and the roll shaft 6a, so that each shaft 6, The pressing force does not act on the shaft supporting portions such as 3b and the case 7, and efficient and balanced driving is performed.

[0009]

As described above, according to the present invention, the dead space of the conventional rotary drum 8 is utilized to increase the high speed rotation and the high torque without changing the size, that is, the high output capacity. At the same time, two types of output of the drive system directly connected to the rotary drum 8 can be obtained. Moreover, since friction drive is used, high rigidity can be obtained, and extremely accurate drive can be obtained which can solve all problems such as backlash of gears and transmission system delay due to weak rigidity of teeth.
It is considered that if the diameter of the rotary drum 8 is reduced, the dead space is eliminated, but if the diameter is reduced (assuming that the tangential force and linear velocity of the drive module 1 ′ are constant), the drive output is low torque and high rotation. Therefore, in order to increase the torque, the number of drive modules 1'provided may be increased. However, since the diameter is small, the space cannot be obtained, and even if high-speed rotation is obtained, low torque is obtained. Although it cannot actually be specified for a drive source such as a physical distribution carrier or a labor-saving device that requires torque, the present invention can provide a stronger drive torque and high rotation, and can be widely applied to high-speed robots. Since it can be used, it will be extremely useful.

[0010]

[Brief description of drawings]

FIG. 1 is a front view of a main part showing an embodiment of an ultrasonic motor having a speed increasing mechanism according to the present invention.

FIG. 2 is a sectional view taken along the arrow line A-A in FIG.

FIG. 3 is a front view of a main part of a conventional ultrasonic motor.

FIG. 4 is a cross-sectional view taken along the line EE.

[0011]

[Explanation of symbols]

 1 Drive Module 1'Drive Module 2 Mounting Bracket 2'Mounting Bracket 3 Rotating Drum 3'Rotating Drum 4 Roller 5 Roller Shaft 6 Shaft 7 Case 8 Rotating Drum 9 Case 3a Inner Ring 3b Shaft 6a Roll Shaft 6b Roll Shaft 8a Shaft

Claims (1)

[Claims] 1. In an ultrasonic motor for rotatively driving a rotary drum by circumscribing a drive module, the shaft and the rotary drum are integrated, the shaft as an output shaft is taken out of a case, and the rotary drum is The roller is housed in a contact ring, and the roller is evenly arranged at least at three points on the circular surface and pressed against it. The roller elastically expands and contracts in the radial direction and becomes rigid in the rotational direction. The roller shafts are rotatably supported by the roller shafts, and the roller shafts are arranged and pressed against the outer diameter portions of the rollers, and the roll shafts are taken out from the case on the opposite side of the shafts as output shafts. The other of the shafts is engaged with the shaft of the rotary drum and supports the rotary shaft, and a drive system for rotating the rotary drum is attached to the case to integrally build the rotary drum. Friction transmission with The ratio is obtained from the ratio (D / d) of the inscribed diameter D of the rotary drum and the diameter d of the roll shaft. The rotary drive from the drive module is directly connected to one shaft and output, and the other side shaft An ultrasonic motor with a built-in speed increasing mechanism, characterized in that two kinds of rotations, that is, a speed-up rotation output of a drive system by friction transmission of a roller inscribed in a rotary drum, are obtained.