JPH03253271A - vibration wave motor - Google Patents

Abstract

PURPOSE:To prevent the deterioration in a characteristic of a motor, the peeling- off of a piezo-electric body or the decline in the strength of adhesion and the overheating in a mounting section of the motor by circulating a cooling medium in a heating section of the motor to cool off. CONSTITUTION:A cooling medium 18 supplied into a case 1 is circulated in the case 1, and the heat in a stator 5 and motor is absorbed to radiate to the outside of the case 1 through an exhaust pipe 17. According to the constitution, overheating in an oscillation body having high temperature dependency is prevented, and it is possible to stabilize a characteristic of the motor. The decline in the strength or coming-off of the adhesive due to temperature rising, with which electric-mechanical energy conversion element such as of the piezo-electric body 4, etc., is joined to the oscillation body 5 can be prevented to promote reliability.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a vibration wave motor that frictionally drives a moving body using progressive vibration waves, and relates to a cooling structure that cools a heat generating part.

[Prior Art] A proposal regarding the structure of a vibration wave motor using bending vibration of a piezoelectric body has been proposed in Japanese Patent Laid-Open No. 73887/1987.

The above proposal is 1) Small and compact vibration wave motor 2) Vibration wave motor with excellent heat dissipation 3) Highly efficient vibration wave motor 4) Vibration wave motor with easy pressure adjustment It provides:

Since the driving principle of the vibration wave motor is well known, it will not be explained in detail, but will be briefly explained below.

In a vibration wave motor, a piezoelectric element is bonded with adhesive to one side of an elastic body made of metal, for example, formed in an annular shape, and two groups of piezoelectric elements for driving formed on the piezoelectric element have different phases. By applying an alternating voltage, two standing waves are excited on the elastic body, and these standing waves are combined to form a progressive vibration wave, which is a bending vibration.

On the other hand, on the other side of the elastic body, an annular member, for example, is pressurized via a pressure means such as a spring, and the member is moved by friction drive caused by progressive vibration waves formed in the elastic body. or move the elastic body.

A conventional example will be explained with reference to FIG.

2 is a cover of the motor, and 1 is a case. A piezoelectric body 4 is fixed to the annular elastic body 3, and these constitute a stator (vibrating body) 5.

Note that the stator 5 generates heat due to thermal energy generated by electrostriction due to energization of the piezoelectric body 4, and the structure is such that the increase in motor temperature due to the heat generation of the stator 5 is conducted and dissipated from the stator 5 to the cover 2 and the case 1. It has become.

Reference numeral 8 denotes a rotor constructed by fixing a slider 7 to a ring 6. This rotor 8 is pressed against the stator 5 by the pressing force of a spring 10 with a rubber body 9 in between, and the shaft 11
It is designed to rotate together with the Pressure force is shim 12
After selecting and adjusting the thickness of the snap ring 13
It can be adjusted very easily. The shaft 11 is rotatably supported by bearings 14 and 15 attached to the case 1 and the cover 2, respectively.

[Problems to be Solved by the Invention] By the way, in the above conventional example, the stator 5
The transmission paths of the thermal energy generated in the stator 5 include heat radiation from the surface of the stator 5, a path from the drive surface to the rotor, and conduction from the stator thin wall portion 3-a to the cover 2 and the case 1 through the stator mounting portion 3-b.・There are three routes for dissipation,
Of this, the heat dissipated from the surface of the stator 5 and the thermal energy conducted to the rotor 8 are very small, and most of the heat is transferred from the third path from the stator thin wall portion 3-a to the cover 2, via the attachment portion 3-b. It will be conducted and dissipated to Case 1.

In this case, the amount of heat conducted per unit time is proportional to the cross-sectional area perpendicular to the conduction direction, so in the conventional example, the cross-sectional area of the thin-walled portion 3-a for providing flexibility is extremely small, and the amount of heat conducted per unit time is The amount of heat that can be conducted and dissipated to the outside of the motor is extremely small, which may lead to overheating of the stator 5, resulting in deterioration of motor characteristics due to the temperature dependence of the stator resonance frequency, or causing the piezoelectric body 4 and elastic body 3 to stick together. There were cases where adhesive strength decreased or peeling occurred.

The purpose of the present invention is to solve the above-mentioned conventional problems, prevent deterioration of Tanabata performance due to overheating, prevent peeling of the piezoelectric material and decrease in adhesive strength, and prevent overheating of the motor mounting part. Our goal is to provide a vibration wave motor that can.

[Means for Solving the Problems] The gist of the present invention, which is related to the object of the present invention, is that by applying an alternating current voltage to an electro-mechanical energy conversion element bonded to an elastic body, It has a vibrating body that forms progressive vibration waves, and a member that is pressed into contact with the vibrating body through a pressure means, and the member and the vibrating body are connected by the progressive vibration waves formed in the elastic body. A vibration wave motor for relative movement is characterized in that it has forced cooling means for circulating a cooling medium to a heat generating part of the motor to cool it.

[Function] The vibration wave motor configured as described above forcibly cools the motor heat generating portion with a cooling medium.

[Example] The present invention will be described in detail below based on an example shown in the drawings.

In the description of the embodiment, members having the same structure as those of the conventional example shown in FIG. 3 are denoted by the same reference numerals, and the description thereof will be omitted.

Embodiment 1 FIG. 1 is a sectional view showing Embodiment 1 of a vibration wave motor according to the present invention.

In this embodiment, a cooling medium 18 such as air is introduced into a closed space formed by a case 1 and a cover 2 and housing a stator 5 and a rotor 8, to perform forced cooling of the stator 5 and the like.

Reference numeral 16 denotes a cooling medium feeding vibrator inserted into a hole ia formed in the side wall surface of the case 1, and 17 a hole 1 formed opposite to the stator 5 at a position symmetrical to the hole 1-a. -b, the cooling medium 18 supplied by a cooling medium charging means (not shown) is supplied into the case 1 from the cooling medium feeding vibration 16.

The cooling medium 18 supplied into the case 1 circulates within the case, absorbs the heat inside the stator 5 and the motor, and exhausts the heat to the outside of the case from the exhaust vibrator 17.

Example 2 FIG. 2 is a sectional view showing the second embodiment.

In the first embodiment described above, the coolant inlet vibrator 16 and the discharge vibrator 17 are provided at symmetrical positions, but in this embodiment, the coolant inlet vibrator 16, the discharge vibrator 17, and the lead wire 19 of the piezoelectric body 4 are covered with an outer jacket. 20 to make a Riet wire vibrator bundle 2
1 and inserted into a hole 1-c drilled in the side wall surface of the case 1, a cooling medium inlet vibrator 16 is provided facing the elastic body 3, and a discharge vibrator 17 is provided above it. There is.

In this embodiment, as in the first embodiment, the cooling medium 18 circulates within the case, thereby absorbing the heat inside the stator 5 and the motor, and exhausting the heat from the exhaust vibrator 17.

[Effects of the Invention] As explained above, according to the present invention, by circulating a cooling medium through the motor heat generating part to cool it, overheating of the vibrating body, which is highly temperature dependent, is prevented and motor performance is stabilized. It becomes possible.

In addition, it is possible to prevent the strength of the adhesive that fixes the vibrating body and the electro-mechanical energy conversion element such as the piezoelectric body from decreasing or peeling off due to a rise in temperature, thereby improving reliability.

By roughly cooling the motor, heat conduction to the motor device mounting portion can be reduced and the effects of heat can be eliminated.

Further, the present invention is very effective in cases where dustproofing is required and the inside of the motor must be hermetically sealed.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a first embodiment of a vibration wave motor according to the present invention, FIG. 2 is a sectional view of a second embodiment, and FIG. 3 is a sectional view of a conventional vibration wave motor. 1...Motor case 2...Cover 3...
Elastic body 4... Piezoelectric body 5... Stator (vibrating body) 6... Ring 7... Slider
8... Rotor 9... Rubber ring 1o.
...Rice spring 11...Shaft 12...Spacer 13...Snap ring 14.15...Bearing 16.17...Pipe 18...Cooling medium 19...Lead wire 20... Outer cover 1st figure 1st figure

Claims (1)

[Scope of Claims] 1. A vibrating body that forms progressive vibration waves in the elastic body by applying an alternating current voltage to an electro-mechanical energy conversion element bonded to the elastic body, and a means for applying pressure to the vibrating body. A vibration wave motor has a member that is pressed into contact with the elastic member through a vibration wave motor, and the vibration wave motor moves the member and the vibrating body relative to each other by progressive vibration waves formed in the elastic body, the vibration wave motor having a cooling medium circulating through a heat generating part of the motor. A vibration wave motor characterized by having a forced cooling means for cooling. 2. Claim 1, wherein the forced cooling means is characterized in that a pipe for feeding a cooling medium is provided in a container that covers the heat generating part of the motor, and a hole or a pipe for discharging the cooling medium is provided in the container.
The vibration wave motor described in . 3. The vibration wave according to claim 1, wherein the cooling means is configured by bundling a pipe for inserting the cooling medium into the container, a pipe for discharging the cooling medium, and a signal line of the electro-mechanical energy conversion element. motor.