JPH02119580A - Ultrasonic motor - Google Patents

Abstract

PURPOSE:To prevent slackness between a rotor and a connector, and to obviate even the slackness of the whole ultrasonic motor by forming a gripping section retainable to the groove of a nut for adjusting contact bonding force and installing a locking member being charged into an expanding slot and preventing the revolution of the nut for adjusting contact bonding force. CONSTITUTION:Grooves 45 are shaped to the whole circumferential surface of a nut 37 for adjusting contact bonding force being screwed to the nose section of a through-bolt 36 penetrated and mounted to an ultrasonic motor 30 and clamping the ultrasonic motor 30 while expanding slots 43 are formed in the axial direction at the nose of the through-bolt 36, a gripping section 48 retainable to the grooves 45 of the nut 37 for adjusting contact bonding force is shaped, and a locking member 38 being inserted into the expanding slots 43 and obviating the rotation of the nut 37 for regulating contact bonding force is mounted. Accordingly, the revolution of the nut 37 for adjusting contact bonding force is engaged with the gripping section 48 of the locking member 38 and the grooves 45 formed to the nut 37 and prevented, and contact bonding force between a rotor 35 and a connector 34 is kept constant while slackness is obviated regarding the whole ultrasonic motor 30.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an ultrasonic motor, and more particularly to a device for preventing changes in the crimp force of a rotor in an ultrasonic motor after adjustment of the rotor crimp force.

[Conventional technology]

Generally, an ultrasonic motor must maintain an appropriate pressure force between the connector and the rotor at all times in order to maintain a predetermined number of rotations. For this reason, it is necessary to always maintain the attached bolts and the like in a securely tightened state.

Conventionally, as the above-mentioned conventional technology, for example, Japanese Patent Application Laid-Open No. 1986-
Ultrasonic motor disclosed in No. 217876 and No. 7
The ultrasonic motor shown in the figure is known.

As shown in FIG. 6, the ultrasonic motor disclosed in JP-A-62-217876 has a thin metal terminal plate with lead wires connected to the electrode surface of a piezoelectric body 1.2 consisting of a donut-shaped disk. 3.4 are stacked on top of each other, the piezoelectric body 1.2 is sandwiched between the aluminum disks 5 and 6, and the connector 7 is placed on the end face of the aluminum disk 5 on the minus side, and each of these members is capped. The bottle 8 is tightened and integrated, and a rotor 9 is rotatably attached to the connector 7.

This rotor 9 is provided with a hollow pulp-like output shaft 10 on its upper part, and the threaded part of a bolt 12 passed through a bearing 11 inside the shaft is made to protrude from a hole 9b of the rotor 9. The rotor 9 is screwed into the screw hole 13 of the crimping surface 7a, and the elastic force of the crimping spring 14 is compressed between the head of the bolt 12 and the bearing 11.
The crimp surface 9a of the connector 7 and the crimp surface 7a of the connector 7 are closely joined.

On the other hand, in the ultrasonic motor shown in FIG. 7, the rotor 15 is
A circular recess 16 is formed in its upper end surface, and it is rotatably attached to the connector 20 via a pole 19 passed through a bearing 17 provided in the recess 16, and the bolt 19 is attached to the body 19a. and a screw portion 1 having a smaller diameter than the body portion 19a.
9b is provided, and the screw portion 19b is screwed into the screw hole 21 provided in the connector 20, and the rotor 15 is connected by the elasticity of the compression spring 22 compressed between the head of the bolt 190 and the bearing 17. The child 20 is configured in close contact with the child 20.

[Problems to be Solved by the Invention] However, the conventional ultrasonic motor described above has the following problems.

That is, in the ultrasonic motor disclosed in Japanese Patent Application Laid-Open No. 62-217876, a locking agent is applied to the threaded portion because the coupling element 7 and rotor 9 become separated due to ultrasonic vibration.
During assembly, there is a risk that the screw may be stopped at a halfway position and may be accidentally touched while the locking agent hardens, or that the rotating shaft may rotate due to vibration, etc. There was a problem in that care had to be taken when handling it. In addition, since a locking agent is used, there are problems with maintenance and repair samurai, such as when readjustment occurs, it is nearly impossible to peel off and disassemble the once hardened locking agent, resulting in defects. there were.

On the other hand, in the ultrasonic motor shown in FIG. 7, the bolts 19 are tightened to an appropriate level during the work process, or bolts 19 with different lengths of the body 19a are selectively used each time. The stepped portion 19c is tightened until it reliably contacts the connector 20, but the tightening easily loosens due to ultrasonic vibrations, requiring a large number of man-hours in production, and cannot be completely tightened. There was a problem in that it did not effectively prevent loosening. Furthermore, when the poles 1-19 are selectively used, a large number of bolts 19 must be prepared, resulting in problems such as being uneconomical.

The present invention has been made in view of the problems of the conventional ultrasonic morph described above, and has a method of constantly holding the rotor and the connector at a constant level with a desired pressure force to prevent loosening between the rotor and the connector. It is an object of the present invention to provide an ultrasonic motor which can also prevent loosening of the entire ultrasonic motor.

[Means to solve the problem]

In order to achieve the above object, in the ultrasonic motor of the present invention, the rotor is crimped onto a surface that generates ultrasonic elliptical vibration and the rotor is rotated. A groove is formed on the entire circumference of a crimp force adjustment nut that is screwed onto the tip of the through bolt to tighten the ultrasonic morph, and a groove is formed in the axial direction at the tip of the through bolt to adjust the crimp force. It is constructed by forming a grip portion that can be freely engaged with the groove of the adjusting nut, and providing a locking member that is inserted into the split groove to prevent rotation of the crimp force adjusting nut.

[Effect]

In the above configuration, the rotation of the crimp force adjusting nut that is screwed onto the through bolt and adjusts the crimp force between the rotor and the connector to the desired pressing force engages the gripping portion of the locking member and the groove provided in the nut. The compressive force between the rotor and the connector is maintained constant, and the entire ultrasonic motor is also prevented from loosening.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

(First Embodiment)- Fig. 1 shows a first embodiment of an ultrasonic motor 30 according to the present invention, Fig. 1a is a partially cutaway front view of the ultrasonic motor 30, and Fig. 1 3 is an exploded perspective view of an ultrasonic motor 30. FIG.

As shown in the figure, the ultrasonic motor 30 includes a piezoelectric element 31 provided with a terminal plate 31a, a collar 32 disposed on one side of the piezoelectric element 31, and a beam 33 disposed on the other side of the piezoelectric element 31. A rotor 35 is held in contact with the connector 34 and the elliptical vibration generating surface 33a of the beam 33, a through bolt 36 having a tip protruding above the rotor 35, and a crimp screwed onto the tip of the through bolt 36. It is composed of a force adjusting nut 37, a locking plate 38 for preventing rotation of the crimp force adjusting nut 37, and the like.

The connector 34 is composed of a disk portion 39 as a base and a beam 33, and has the circumference of the axis 3 of the disk 39 and the side surface 40 in the counter-rotation direction of the rotor 35 axially symmetrical with respect to the axis a. ,
It is formed into a horn shape with a beam lower part 41 at the axis a remaining. That is, a U-shaped recess 43 is formed in the center of the beam 33 from the elliptical vibration generating surface 33a, and there is an appropriate height between the bottom surface of the recess 43 and the plate surface of the disc 39. The beam is set so that the lower part 41 of the beam remains. Two beam parts are formed by the U-shaped recess 43, which are divided in the longitudinal direction of the beam 33 with the axis a as the center. side 40 and opposite side 40 of
A is formed as a vertical surface, and the other side surface 40 is formed as a curved surface, and the shape of each beam portion described above is formed symmetrically with respect to the axis a.

The rotor 35 has a crimp surface 35a that contacts the elliptical vibration generating surface 33a at its lower end surface, a recess 35b formed from its upper end surface, and a bearing 41 fitted into the recess 35b.

The through bolt 36 is attached to the collar 32. Piezoelectric element 31° rotor 34. A distal end portion 36a thereof protrudes through the rotor 35 and the bearing 41.

A threaded portion 42 is formed on this tip portion 36a, and a slot (split groove) 43 is provided in the direction of the axis a.

The crimp force adjustment nut 37 is screwed onto the threaded portion 42, presses and holds the rotor 35 and the elliptical vibration generating surface 33a of the rotor 34 with a desired crimp force via the disk spring 44, and presses and holds the rotor 35 and the elliptical vibration generating surface 33a of the rotor 34 with a desired crimp force, A serrated groove 45 that can be freely engaged with the lock plate 38 is formed on the surface.

The lock plate 38 is inserted into the slot 43 to prevent the crimp force adjustment nut 37 from rotating. Two legs 4 protrude in parallel from both sides of the main body.
It consists of 7. A gripping portion 48 that grips the nut 37 by engaging with a groove 45 formed in the crimp force adjusting nut 37 is formed in a protruding manner at the distal end of each leg portion 47 . That is, the re-grip portion 48 is formed such that the interval T1 between its tip portions is larger than the root diameter of the groove 45 of the nut 37, and the interval T! between the intermediate portions thereof. is formed to be slightly smaller than the root diameter of the groove 45, and has a spring effect to grip the nut 37. In addition, in order to make it easier to hold, a continuous sloped or curved surface is formed from the tip end to the middle part.

In the ultrasonic motor 30 having the above configuration, the lock plate 38
is not inserted into the slit 43, while rotating the crimp force adjustment nut 37, set the desired pressing force to the disc spring 44. The crimping surface 35a of the rotor 35 is connected to the connector 34 via the bearing 41.
Adjust so that it is pressed against the elliptical vibration generating surface 33a of
Next, insert the main body 46 of the lock plate 38 into the slot 43 from above, and insert the tip of the grip 48 into the groove 45 of the nut 37.
While guiding the nut 37 inward, the lock plate 38 is lowered and the circumferential surface of the nut 37 is clamped by the intermediate portion of the grip portion 48 to prevent the nut 37 from rotating.

Note that the groove 45 formed around the entire circumference of the crimp force adjustment nut 37 has a rectangular cross-sectional shape (FIG. 2b), and a groove in which the ridgeline of the convex portion is chamfered linearly (FIG. 2b). Diagram c
), the ridgeline of the convex portion can be formed into a shape such as eight chamfered edges (FIG. 2 d).

According to this embodiment, the lock Fi3B has the through bolt 36
Rotation is prevented by the slit 43 at the tip 36a of the tip 36a, and the screw is screwed onto the through bolt 36, and the crimping force between the elliptical vibration generating surface 33a of the connector 34 and the crimping surface 35a of the rotor 35 and the entire ultrasonic motor 30 are prevented. Rotation of the crimp force adjusting nut 37 for tightening can be prevented by engagement between the grip portion 48 of the lock plate 38 and the groove 45 provided around the entire circumference of the nand 37.

Therefore, the nut 37 can be fixed at any position, and a desired pressure force can be constantly applied and maintained between the connector 37 and the rotor 35.

Furthermore, simply by press-fitting the lock plate 38 into the slot 43 from above, the nut 37 can be prevented from rotating and fixed, and the assembly of the ultrasonic motor 30 can be automated.

Note that the lock plate 38 is attached to the main body 4 as shown in FIG.
It can be configured by providing a stopper 50 at the lower end of 6. For example, even if the thickness of the main body part 46 is thinner than the groove width of the slot 43, the lock plate 3 and the slot 43 can be firmly fixed without play. This makes it possible to prevent the crimp force adjustment nut 37 from rotating.

(Second Embodiment) FIG. 4 shows a second embodiment of the ultrasonic motor according to the present invention. In the figure, only the lock plate 51 is shown, and the other configurations are the same as those of the first embodiment, so illustration and explanation thereof will be omitted.

The lock plate 51 in this embodiment has a circular hole 53 above the main body 52, and other structures are the same as in the first embodiment, so the same parts are given the same numbers. , the explanation thereof will be omitted. It should be noted that the shape of the hole 53 is not limited to a circular shape, but can be configured and implemented in any shape such as an ellipse or a rectangle.

According to this embodiment, the same functions and effects as those of the first embodiment can be achieved, and in addition, the lock plate 38 can be easily taken out from the slot by hooking a hook or the like into the hole. , rotor replacement after rotor wear as a result of readjustment of rotor crimp force and torque transmission of ultrasonic vibrations;
Readjustment can be easily performed.

(Third Embodiment) FIG. 5 shows a third embodiment of the ultrasonic motor according to the present invention. In the figure, only the lock plate 55 is shown, and the other configurations are the same as those of the first embodiment, so illustration and explanation thereof will be omitted.

The lock Fi 55 in this embodiment is configured by forming a taber 59 on the edge of the grip portion 58 of the leg portion 57 protruding from the main body portion 56 . That is, as shown in an enlarged view in FIG. 5, the end surface of the gripping portion 58 is formed to have a width narrower than the hinge T of the groove 45 provided around the entire circumference of the pressure-adjusting nut 37.

According to this embodiment, the same functions and effects as those of the first embodiment described above can be obtained. Further, a taber 59 is attached to the grip portion 58.
, the lock plate 55 and the groove 45 can be more easily engaged, and the crimp force adjustment nut 37 can be prevented from rotating and the crimp force between the rotor and the connector can be adjusted more accurately. be able to.

〔Effect of the invention〕

As described above, according to the present invention, even if an ultrasonic motor is used for a long period of time, the desired pressing force between the rotor and the connector can be maintained, and separation between the rotor and the connector can be prevented, and the connection The elliptical vibration generated in the child can be efficiently transmitted to the rotor.

Furthermore, a desired pressure bonding force can be maintained with a simple structure consisting of a nut and a locking member, and the locking member can be assembled from above the slit, thereby making it possible to automatically assemble the ultrasonic morph. As a result, it is possible to provide an inexpensive ultrasonic motor that can easily and stably maintain high torque and high rotation for a long period of time.

[Brief explanation of drawings]

Fig. 1 shows a first embodiment of the ultrasonic motor according to the present invention, Fig. 1a is a partially cutaway front view of the ultrasonic motor, and Fig. 1 is an exploded perspective view of the ultrasonic motor. Figure, Figure 2 a-
d is a plan view showing an enlarged part of the crimp force adjustment nand;
FIG. 3 is a perspective view showing another embodiment of the locking member, FIG. 4 is a perspective view showing main parts of the second embodiment of the ultrasonic motor according to the present invention, and FIG. 5 is a perspective view showing another embodiment of the locking member. 3rd part of ultrasonic motor
A perspective view showing a main part of the embodiment, and FIGS. 6 and 7 are cross-sectional views showing a conventional ultrasonic morph. 30...Ultrasonic motor 34...Connector 35...Rotor 36...Through bolt 37...Crimping force adjustment nut 3 days...Lock plate 43...Slot 48... Gripping part

Claims (1)

[Claims] In an ultrasonic motor that rotates the rotor by crimping the rotor to a surface that generates ultrasonic elliptical vibrations, the crimping force adjustment is used to tighten the ultrasonic motor by screwing it into the tip of a through-bolt that passes through the ultrasonic motor. A groove is formed on the entire circumferential surface of the nut for adjusting the pressure, and a groove is formed in the axial direction at the tip of the through bolt to form a gripping part that can be freely engaged with the groove of the crimp force adjustment nut. 1. A piezoelectric motor characterized in that the piezoelectric motor is constructed by providing a locking member that prevents rotation of the crimp force adjusting nut when inserted into the piezoelectric motor.