JPH081366U - Ultrasonic motor - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To obtain an ultrasonic motor having a vibrating body that is excellent in durability with less abrasion of a friction material and has good self-starting property. SOLUTION: The chamfers 4c, 4c 'are formed on the inner peripheral side ridge line and the outer peripheral side ridge line of the tip end portion of the comb tooth 4a with respect to the circumferential direction of the comb tooth portion 4a where the friction material 3 and the vibrating body 4 are in contact with each other.
Is given. By chamfering the tips of the comb teeth 4a in this manner, it is possible to realize an ultrasonic motor having good self-starting characteristics even when driven, less abrasion of the friction material 3, and excellent durability. .

Description

[Detailed description of the device]

[0001]

[Technical field to which the device belongs]

 The present invention relates to the shape of a vibrator of an ultrasonic motor.

[0002]

[Prior art]

 In a general ultrasonic motor that has been considered in the past, as shown in FIGS. 3 and 4, by applying a high frequency voltage of two different phases to the vibrating body 4 to which the piezoelectric element 5 is bonded, A traveling wave is generated in the vibrating body, and the friction material 3 adhered to the moving body 2 and the surface of the vibrating body 4 that is in contact with the friction material 3 and forms the comb tooth portion 4a are pressed and driven.

[0003]

[Problems to be solved by the device]

 In the structure of the ultrasonic motor as described above, since the comb teeth of the vibrating body and the friction material attached to the moving body are pressed to rotate, the soft friction material is worn away. Also, when the maximum displacement position of the vibrating body varies from individual to individual, and when the comb teeth part has deviated from the maximum displacement position in the radial direction, the friction material will change depending on the contact method between the comb teeth part and the friction material. The way it was shaved was wrong. Further, if left in a static state, the vibrating body will slip into the friction material, increasing the static torque and deteriorating the self-startability.

Therefore, an object of the present invention is to obtain an ultrasonic motor having a vibrating body which has less abrasion of the friction material and which is excellent in durability and has a good self-starting property.

[0005]

[Means for Solving the Problems]

 In order to solve the above-mentioned problems, the present invention relates to an ultrasonic motor, wherein an inner peripheral side ridge line and an outer peripheral side of a tip portion of a plurality of comb teeth of a vibrator having a plurality of comb teeth arranged in an annular shape. The chamfered portion is provided on the ridgeline of.

In addition, the chamfered portions are provided on all the ridge lines of the tips of the plurality of comb teeth of the vibrating body. According to the above-mentioned configuration, the friction material is less likely to be scraped, and the abrasion powder generated by scraping the friction material is reduced. Further, since the friction material is prevented from sinking into the vibrating body even when it is left stationary, a vibrating body having excellent durability and good self-starting property can be obtained.

[0007]

[Embodiment of device]

 An embodiment of the present invention will be described below with reference to the drawings. 3 and 4 show a general ultrasonic motor. The moving body 2 to which the friction material 3 is adhered has the central axis 1, and is rotatable via the bearing 6 to the vibrating body 4 to which the piezoelectric element 5 is adhered. The moving body 2, which is in pressure contact with the vibrating body 4, is moved by the bending vibrating wave component generated by applying two high-frequency voltages having different phase differences to the piezoelectric element 5 bonded to the vibrating body 4. The comb tooth portion 4a is frictionally driven to rotate. The comb tooth 4a referred to here is a so-called displacement magnifying mechanism for magnifying a minute bending vibration wave component generated on the surface of the vibrating body 4.

FIG. 1 and FIG. 2 show a first embodiment of a vibrating body of an ultrasonic motor according to the present invention, in which the friction material 3 and the vibrating body 4 shown in FIG. 4 are in contact with each other. Chamfers 4b and 4b 'are formed on both sides of the comb tooth 4a in the circumferential direction of the comb tooth portion 4a. By chamfering 4b and 4b 'on both sides in this way, it is possible to realize an ultrasonic motor that has good self-starting characteristics even when it is driven and that has little abrasion of the friction material 3 shown in FIG. 4 and has excellent durability. Becomes

5 (a), (b), (c) and (d) are diagrams showing the behavior of the comb tooth portion according to the change of the comb tooth setting position according to the present invention. Here, FIG. 5 (a) is a diagram showing the behavior in the longitudinal direction in the radial direction of the vibrating body, FIG. 5 (b) is a diagram showing the case where the comb tooth setting position is set on the maximum displacement position, FIG. FIG. 5 (c) is a diagram showing a case where the set position of the comb teeth is displaced outward from above the maximum displacement position, and FIG. is there.

When the maximum displacement position of the vibrating body 4 varies from one to another, and as shown in FIGS. 5C and 5D, the comb tooth portion 4a is displaced from the maximum displacement position in the radial direction. In this case, in order to exhibit the behaviors shown in FIGS. 5 (c ') and 5 (d'), respectively, depending on how the comb teeth 4a and the friction material 3 shown in FIG. The way the friction material 3 was shaved was different as shown in. Further, when it was left standing still, the comb tooth portion 4a was caught in the friction material 3 shown in FIG. 4, and the self-starting property deteriorated.

Therefore, as in the embodiment shown in FIGS. 6 and 7, the comb tooth portion 4 a, which is the portion where the friction material 3 and the vibrating body 4 are in contact with each other, shown in FIG. The above problem is solved by chamfering the inner and outer circumferences of the tooth portion 4a.

8 and 9 show a third embodiment according to the present invention, and the chamfers 4b and 4b 'shown in FIGS. 1 and 2 above and FIGS. 6 and 7 above. It is a figure when both the examples of 4c and 4c 'are combined. Also, the same effect can be obtained by cutting the corners of the chamfered comb tooth portion 4a shown in FIGS. 1 and 2 and FIGS. 6 and 7 into a circle instead of chamfering.

In the embodiment described above, the vibrating body 4 of the ultrasonic motor is chamfered by the chamfering of the ridge line formed by the surface in contact with the friction material 3 and the vertical surface forming the comb tooth portion 4a. Is less likely to be scraped, and the amount of wear debris is reduced. Further, even if the vibrating body 4 sinks into the friction material 3, since it is chamfered and has no corners, a vibrating body having a good self-starting property can be obtained.

[0014]

[Effect of device]

 In this ultrasonic motor, a chamfered portion is provided on the inner peripheral edge line and the outer peripheral edge line of the tips of a plurality of comb teeth of a vibrating body having a plurality of annularly arranged comb teeth. And Also, because the chamfered parts are provided on all the ridges of the tips of the multiple comb teeth of the vibrating body, the abrasion of the friction material is small and the durability is excellent, and even when left standing still The effect is that an ultrasonic motor having a friction material with good self-starting can be obtained.

[Brief description of drawings]

FIG. 1 is a plan view showing a first embodiment of a vibrating body of an ultrasonic motor according to the present invention.

FIG. 2 is a sectional view of the first embodiment.

FIG. 3 is a plan view of a vibration body of a conventional general ultrasonic motor.

FIG. 4 is a sectional view of a conventional general ultrasonic motor.

FIG. 5 is an explanatory view showing the behavior of the comb tooth portion according to the variation of the comb tooth setting position according to the present invention.

FIG. 6 is a plan view showing a second embodiment of a vibrating body of an ultrasonic motor according to the present invention.

FIG. 7 is a cross-sectional view of the second embodiment.

FIG. 8 is a plan view showing a third embodiment of a vibrating body of an ultrasonic motor according to the present invention.

FIG. 9 is a sectional view of a third embodiment.

[Explanation of symbols]

 2 moving body 3 friction material 4 vibrating body 4a comb tooth

Claims (2)

[Scope of utility model registration request] 1. An ultrasonic motor having a vibrating body that generates a vibrating wave and a moving body that is frictionally driven by the vibrating body, wherein the vibrating body has a plurality of comb teeth arranged in an annular shape,
An ultrasonic motor, characterized in that chamfered portions are provided on the ridge lines on the inner peripheral side and the ridge lines on the outer peripheral side of the tips of the plurality of comb teeth of the vibrating body. 2. The ultrasonic motor according to claim 1, wherein chamfered portions are provided on all the ridgelines of the tips of the plurality of comb teeth.