JPS63220777A - Ultrasonic motor - Google Patents

Abstract

PURPOSE:To improve output efficiency, and to miniaturize an ultrasonic motor by forming a slit from one surface of a stator, shaping a contact surface at a stepped section and fixing a piezoelectric element to the side surface of the stator. CONSTITUTION:With an ultrasonic motor, piezoelectric elements 1 conducting longitudinal vibrations arc fastened to side surfaces partitioned by slits 3 formed from one surface of a stator 2. A rotor 4 is mounted to the stator 2 as the state of pressure is left as it is by a machine screw 8 through a bearing 5, a washer 6, a spring 7, etc. on the surfaces on the slit 3 side of said stator 2. Stepped sections 9 are shaped besides the slits 3 to the stator 2, and contact surfaces 10 are formed. Accordingly, when voltage is applied to the piezoelectric element 1 and the element 1 is driven, the stator 2 conducts flexural vibrations in the slits 3, and a vector is worked to the contact surfaces 10 and the rotor 4 is turned.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention 1 (Industrial Application Field) The present invention relates to an ultrasonic motor that utilizes bending vibration.

(Prior Art) Ultrasonic motors using piezoelectric bare hands are being researched and developed, but their principles and structures vary. for example,
An ultrasonic motor that performs rotational motion using elastic traveling waves has a plurality of piezoelectric elements 6 as shown in FIGS. 22 and 23.
1 is attached to an elastic ring and the piezoelectric elements 61 are sequentially driven with a signal having a small phase, an elastic traveling wave 63 that performs an elliptical motion is generated in the elastic ring 62.

This elliptical motion was used to rotate the rotor 64 which was brought into pressure contact with the elastic ring 62, but the ultrasonic motor with this configuration requires a large number of piezoelectric elements 61, and these piezoelectric elements 61 The drive circuits had to be driven by signals with different phases, which made the drive circuits complicated and large in size. Further, since rotational motion is obtained using the elliptical motion of the elastic traveling wave 63 generated in the elastic ring 62, there is a problem in that the mechanical energy output is small relative to the input electrical energy and the efficiency is low.

(Problems to be Solved by the Invention) The present invention provides an ultrasonic motor that uses a piezoelectric element that vibrates in the longitudinal direction, has a simple drive circuit configuration, has high output efficiency, and can be made compact. It is.

[Configuration 1 of the Invention (Means for Solving Problems) The ultrasonic motor according to the present invention has a slit provided from one side of the stator, and a contact surface formed by a step formed on the surface provided with the slit, The rotor is brought into contact with or brought into contact with the contact surface, and a piezoelectric element fixed to the side surface of the stator divided by the slit is driven, thereby bending the stator and rotating the rotor.

(Function) The ultrasonic motor of the present invention generates bending vibration in the stator by driving a piezoelectric element that vibrates in the longitudinal direction, and directly transmits the bending vibration to the rotor. Transferring information to others is more efficient.

(Example) Example 1 As shown in an exploded perspective view in FIG. 1 and an assembled view in FIG. The rotor 4 is attached to the side surface of the stator 2 with the slit 3 formed thereon by means of adhesive or the like. Washi 1
/6° It is attached to the stator 2 in a pressurized state by screws 8 via a spring 7 or the like. As shown in the figure, the stator 2 has the two slits 3 formed therein and also has a step 9.
A contact surface 10 is formed by the step 9.

When the piezoelectric element 1 is driven by applying a voltage in an ultrasonic wave having such a configuration, the stator 2 forms two slits 3, so that the bending vibration 11 as shown in the figure is generated. As a result, a vector of 12 acts on the contact surface 10, causing the rotor 4 to rotate. Other examples of this stator 2 are shown in FIGS. 3 to 6, each with 10a
, 10b.

10c and 10d are contact surfaces that contact the rotor, and 9a, 9b, 9c, and 9d are steps. In addition, in FIGS. 3 to 5, the sleeve 1-3a is shown.

Although the slits 3b and 3c are straight and parallel, the slits 3d may be curved as shown in FIG. In Fig. 2, the stator 2 undergoes first-order bending vibration 1.
Although it has been described that 1 is performed, it is also possible to perform high-order bending vibration by changing the driving frequency. Furthermore, enlarged views of the contact surfaces of the stator are shown in FIGS. 7 to 10. As shown in FIGS. In this case, when the stator is bent, the area in contact with the rotor can be increased, so it has been confirmed that it has a larger torque and has excellent transmission efficiency. The contact surface 10q may have a slope rising from the outside to the inside as shown in FIG. 9, or the contact surface 10h may have a curved slope as shown in FIG. It is possible to arbitrarily determine the rotational direction of the ultrasonic wave using such a gradient.

Although it has been described in FIG. 2 that the stator 2 is in contact with the rotor 4 at the contact surface 10, the rotor 4 may be brought into contact with the contact surface 10 only when bending vibration is performed.

Embodiment 2 As shown in a perspective view in FIG. 11 and a plan view in FIG. An ultrasonic motor is constructed using other parts similar to those shown in FIGS. 1 and 2 of the first embodiment. Note 2
1 indicates a portion to which the piezoelectric element is fixed. As other embodiments of such a stator, the contact surface 30a formed by the step 29a is subdivided into circumferential parts as shown in FIG. 13, or the contact surface 30a formed by the step 29b as shown in FIG.
0b may be subdivided in the radial direction. A similar effect can be obtained by providing a step and a contact surface which are a combination of circumferential and radial directions, or a contact surface having a slope may be used.

Example 3 Fig. 15 shows a perspective view, and Figs. 16 to 18 show plan views.
An example of an ultrasonic motor using a 1F electric element that vibrates in the longitudinal direction, and other components similar to those of Example 1 and Ii'g is shown. That is, FIGS. 15 and 16 show the slit 33 degree step 39 and the contact surface 40 formed, and FIG. 17 shows the contact surface 40a subdivided into linear shapes. Also, change the shape of the stator to 6 as shown in Figure 18.
The same effect is obtained when the stator has a polygonal shape, such as one in which the contact surface 40b1 step 39b; J3 and slit 33b are formed as a rectangular shape.

Embodiment 4 FIG. 19 shows an exploded perspective view, and FIGS. 20 and 21 show plan views of the stator. That is, a piezoelectric cord 41 that vibrates in the longitudinal direction is attached to a side surface of a stator 42 separated by a slit 43, and a rotor 44 is connected to a spring 47 through a bearing 45° plate 46. screw 48
The stator 42 is pressurized by the stator 42.

In FIG. 20, the contact surface is 60 and the height difference is 59. Also, in Figure 21, in J3, the contact point is 60a.

The step is 59a. Note that 53 is a slit. In this embodiment as well, the shape of the stator is not limited to a circular shape, but a polygonal shape such as a quadrangular shape may be used.

In addition to the embodiments described above, the contact surface may have a slope, or the contact surface may be subdivided into steps having a slope. In addition, although two or more slits were formed in the stator in the example, a single slit in the center or off-center may be used, the sides and bottom of the slit may be stepped, or the width of the slit may be varied. But it doesn't matter. Note that the slit drawing and slit shape are not limited to each of the above individually described, but may be constructed from a combination of each as necessary, or may be constructed as appropriate within the scope of design changes. It is also possible to obtain bending vibration, and the same effect as in the embodiment can be obtained (q).Roughly speaking, the drive number 18 of the piezoelectric element may be not only an alternating current signal but also a pulse signal.

Also, rubber on the rotor and/or contact surfaces.

11 made of JliM, polymeric materials or composite materials thereof, etc. A rubbing material or the like may be provided.

[Effects of the Invention] According to the ultrasonic motor of the present invention, there is no need for driving signals with appropriate phases for each of the plurality of piezoelectric elements as in the conventional case, and the ultrasonic motor can be used in the longitudinal direction! By simply applying a single-phase drive signal to the piezoelectric element r that performs the vibration, the structure and circuit are simple, and since direct bending vibration is used, the transmission efficiency from the stator to the rotor is extremely high. Correct the effect that is out of place.

[Brief explanation of the drawing]

4. FIGS. 1 to 21 show embodiments of the present invention. Fig. 1 is an exploded perspective view of the ultrasonic motor, Fig. 2 is a front view of the ultrasonic motor, Figs. 3 to 6 are plan views showing examples of the stator, and Figs. 7 to 10 are FIG. 11 is a partially enlarged front view showing a stator with a sloped contact surface; FIG. 11 is a perspective view showing another embodiment of the stator; FIGS. 12 to 14 are plan views showing other embodiments of the stator; FIG. 15 is a perspective view showing another embodiment of the stator, FIGS. 16 to 18 are plan views showing another embodiment of the stator, and FIG. 19 is an exploded perspective view of an ultrasonic motor according to another embodiment. , FIG. 20 and FIG. 21 are plan views of stators according to other embodiments, FIG. 22 is an exploded perspective view of a conventional ultrasonic motor, and FIG. 23 is a diagram showing the configuration of a conventional ultrasonic motor. FIG. 1...Piezoelectric element, 2...Stator, 3...Slit. 4... Rotor, 9... Step, 10... Contact surface. 11...Bending vibration, 12...Vector patent
Applicant: Hito Marukon Electronics Co., Ltd. Exploded perspective view of the ultrasonic motor Figure 1 Front view of the ultrasonic motor Figure 3 Figure 4 Plan view of the stator Figure 5 Plan view of the stator
Figure 6 Figure 7
No. 8 Figure 9
No. 10 No. 13
Figure 14: Perspective view of another embodiment of the stator Figure 15: Plan view of another embodiment of the stator Figure 16: Plan view of another embodiment of the stator Figure 17: Plane view of another embodiment of the stator 18 Figure 19 Disassembled perspective view of ultrasonic motor of another embodiment
FIG. 20 A plan view of a stator according to another embodiment. FIG. 21 A plan view of a stator according to another embodiment.

Claims (3)

[Claims] (1) a stator having one or more slits from one surface and a step provided on the surface where the slits are formed; a piezoelectric element that vibrates in the longitudinal direction and is fixed to a side surface of the stator divided by the slits; An ultrasonic motor comprising: a rotor that abuts the stator; the rotor contacts a contact surface formed by steps of the stator. (2) The ultrasonic motor according to claim (1), wherein the contact surface formed by the steps is subdivided. (3) The ultrasonic motor according to claim (1) or (2), wherein the contact surface has a slope.