CN105827148B - A kind of dust protected traveling wave type ultrasonic motor precompression rotor-support-foundation system - Google Patents

Abstract

A dust-proof traveling wave type ultrasonic motor pre-pressure rotor system, including a central shaft, a motor casing, a rotor and a gland, the motor casing and the rotor are sequentially sleeved on the central shaft, the motor casing and the rotor are arranged concentrically, and the gland It is arranged on the top of the central shaft; the surface of the rotor is provided with a pre-pressing point, and the gland is in contact with the pre-pressing point, and the thickness of the rotor gradually becomes thinner from the center to the outside to produce elastic deformation; with this pre-pressed rotor system, the motor Both the output stall torque and the no-load speed can be increased by more than 50%, which can greatly improve the output performance of the traveling wave ultrasonic motor and provide solutions for more applications; Preloaded rotor system with good contact between the driving surface and the friction interface of the rotor.

Description

A Dustproof Traveling Wave Ultrasonic Motor Preloaded Rotor System

technical field

The invention relates to a dust-proof traveling wave ultrasonic motor pre-pressure rotor system, which belongs to the field of ultrasonic motors.

Background technique

Ultrasonic motor is a new concept of micro motor. It uses the inverse piezoelectric effect of the piezoelectric material to excite the elastic body to vibrate slightly in the ultrasonic frequency range, and convert it into the rotation (linear) of the rotor (mover) through the friction between the stator and the rotor (mover) sports. In 1983, Japan's Sashida proposed and manufactured a traveling wave ultrasonic motor, which realized the conversion from standing wave fixed point and regular pushing of the rotor to continuously pushing the rotor by traveling waves, which greatly reduced the friction on the contact surface between the stator and the rotor. wear and tear. The traveling wave type rotary ultrasonic motor is pasted with a piezoelectric ceramic element on one side of the stator. The piezoelectric ceramic element is divided into two groups of polarization, and the same frequency with a phase difference of 90 degrees is applied to the two groups of piezoelectric ceramic elements (ultrasonic frequency domain), constant amplitude alternating voltage. Through the inverse piezoelectric effect of the piezoelectric ceramic element, two modal responses with equal amplitude and 90 degrees difference in time and space can be excited at the modal frequency of the stator. These two modal responses superimpose on the stator to form a traveling wave. If a certain pre-pressure is applied to the rotor at this time, through the friction between the stator and the mover, then the slight vibration of the particles on the surface of the stator will be converted into the rotational motion of the rotor. The interior of the traveling wave ultrasonic motor rotor proposed by Sashida is a continuously variable cross-section annular structure, and the preloading method is that the shaft shoulder is directly connected with the rotor, and the motor casing is pressurized to generate preloading. This preloaded rotor system has the following disadvantages:

1. The internal variable interface annular structure of the rotor has complex processing technology, high processing difficulty and low yield;

2. When pressure is applied to the center of the rotor, the contact part between the outer end of the rotor and the stator of the motor is prone to warping, and it is difficult for the rotor friction interface to fully contact the stator driving surface. Usually, only part of the friction interface is in contact with the stator driving surface;

3. Due to the incomplete contact of the friction interface, the output performance of the motor is low.

Contents of the invention

The invention provides a dust-proof traveling wave type ultrasonic motor pre-pressure rotor system, using the pre-pressure rotor system, the motor output stall torque and no-load speed can be increased by more than 50%, can greatly improve the traveling wave type ultrasonic motor The output performance provides solutions for more applications; moreover, the pre-pressure rotor system is a pre-pressure rotor system with simple processing technology and good contact between the stator driving surface and the rotor friction interface.

The technical solution adopted by the present invention to solve its technical problems is:

A dust-proof traveling wave type ultrasonic motor pre-pressure rotor system, including a central shaft, a motor casing, a rotor and a gland, the motor casing and the rotor are sequentially sleeved on the central shaft, the motor casing and the rotor are arranged concentrically, and the gland It is arranged on the top of the central shaft; the surface of the rotor is provided with a pre-compression point, and the gland is in contact with the pre-compression point, and the thickness of the rotor gradually becomes thinner from the center to the outside for elastic deformation;

As a further preference of the present invention, the rotor is a segmented stepped rotor, a square hole is opened in the middle of the rotor, the upper surface inside the rotor is a three-stage step, the lower surface inside the rotor is a two-stage step, and the thickness of the step is determined by the rotor. The center gradually becomes thinner outward;

As a further preference of the present invention, the rotor system also includes a stator and a motor base, the stator is installed on the motor base, the rotor, the gland, the central shaft, and the motor casing are sequentially installed on the stator, and are all arranged concentrically, and the central shaft There is an adjusting gasket between the shoulder of the shaft and the motor housing;

As a further preference of the present invention, the gland is detachably connected to the top of the central shaft, the gland is a concave circular plate with a center hole, and the central shaft is a round shaft with a shoulder;

As a further preference of the present invention, the gland is integrally formed with the central shaft;

As a further preference of the present invention, the outer upper surface of the gland is provided with a protruding first annular groove, and the outer diameter of the gland is equal to the diameter of the second step on the upper surface of the rotor;

As a further preference of the present invention, the inner surface of the motor casing is provided with a protruding second annular groove;

As a further preference of the present invention, after the motor is installed in the first annular groove and the second annular groove, the two annular grooves are fitted into each other to form a labyrinth structure.

Through the above technical solutions, compared with the prior art, the present invention has the following beneficial effects:

The invention simplifies the processing technology of the motor rotor, and applies a pre-pressure on the edge of the second step on the upper surface of the rotor through the gland, so that the contact between the friction interface of the rotor and the driving surface of the stator is greatly improved. Compared with the system, the output stall torque and no-load speed of the traveling wave ultrasonic motor can be increased by more than 50%.

Description of drawings

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

Fig. 1 is a cross-sectional view of a traveling wave ultrasonic assembly of the present invention;

Fig. 2 is a sectional view of the segmented rotor structure proposed by the present invention;

Fig. 3 is a structural schematic diagram of the pre-pressure rotor system proposed by the present invention;

Fig. 4 is a structural schematic diagram of the detachable connection between the gland and the top of the central shaft of the present invention;

Fig. 5 is a structural schematic view of the integral molding of the gland and the central shaft of the present invention.

In the figure: 1. Motor shell; 2. Rotor; 3. Gland; 4. Stator; 5. Central shaft; 6. Adjusting gasket; 7. Motor base.

detailed description

The present invention is described in further detail now in conjunction with accompanying drawing. These drawings are all simplified schematic diagrams, which only illustrate the basic structure of the present invention in a schematic manner, so they only show the configurations related to the present invention.

As shown in Figures 1 to 3, a dust-proof traveling wave type ultrasonic motor pre-pressure rotor system of the present invention includes a central shaft, a motor casing, a rotor and a gland, and the motor casing and the rotor are sequentially socketed in the center On the shaft, the motor casing and the rotor are concentrically arranged, and the gland is arranged on the top of the central shaft; the surface of the rotor is provided with a pre-pressing point, and the gland is in contact with the pre-pressing point, and the thickness of the rotor gradually becomes thinner from the center to the outside;

As a further preference of the present invention, the rotor is a segmented stepped rotor, a square hole is opened in the middle of the rotor, the upper surface inside the rotor is a three-stage step, the lower surface inside the rotor is a two-stage step, and the thickness of the step is determined by the rotor. The center gradually becomes thinner outward; the rotor is elastically deformed by the action of the gland to obtain the preload required for motor operation. This structure can effectively elastically deform and generate a suitable preload;

As a further preference of the present invention, the rotor system also includes a stator and a motor base, the stator is installed on the motor base, the rotor, the gland, the central shaft, and the motor casing are sequentially installed on the stator, and are all arranged concentrically, and the central shaft There is an adjusting gasket between the shoulder of the shaft and the motor casing. When the motor casing and the motor base are fixed with screws, the rotor shows a certain elastic deformation and produces the required preload. The value of the preload is determined by the adjusting gasket. Decide;

As shown in Figure 4, as a further preference of the present invention, the gland is detachably connected to the top of the central shaft, the gland is a concave circular plate with a center hole, the central shaft is a round shaft with a shoulder, and the motor casing is directly first Generate pressure on the central shaft, then transmit the pressure to the gland through the contact between the shaft shoulder and the gland, and finally transmit the pressure to the rotor through the gland;

As shown in Figure 5, as a further preference of the present invention, the gland and the central shaft are integrally formed, and the motor casing directly generates pressure on the integrated structure, and the pressure is transmitted to the rotor through the integrated structure;

As a further preference of the present invention, the outer upper surface of the gland is provided with a protruding first annular groove, and the outer diameter of the gland is equal to the diameter of the second step on the upper surface of the rotor;

As a further preference of the present invention, the inner surface of the motor casing is provided with a protruding second annular groove;

As a further preference of the present invention, after the motor is installed, the first annular groove and the second annular groove are fitted into each other to form a labyrinth structure, which can effectively prevent the excess friction between the stator and rotor of the motor from invading the motor in bearings built into the housing.

Those skilled in the art can understand that, unless otherwise defined, all terms (including technical terms and scientific terms) used herein have the same meaning as commonly understood by those of ordinary skill in the art to which this application belongs. It should also be understood that terms such as those defined in commonly used dictionaries should be understood to have a meaning consistent with the meaning in the context of the prior art, and will not be interpreted in an idealized or overly formal sense unless defined as herein Explanation.

The meaning of "and/or" in this application means that each exists alone or both exist simultaneously.

The meaning of "connection" in this application may be a direct connection between components or an indirect connection between components through other components.

Inspired by the above-mentioned ideal embodiment according to the present invention, through the above-mentioned description content, relevant workers can make various changes and modifications within the scope of not departing from the technical idea of the present invention. The technical scope of the present invention is not limited to the content in the specification, but must be determined according to the scope of the claims.

Claims (5)

1. A dust-proof traveling wave type ultrasonic motor pre-pressure rotor system, comprising a central shaft, a motor housing, a rotor and a gland, the motor housing and the rotor are sequentially socketed on the central shaft, the motor housing and the rotor are arranged concentrically, The gland is arranged on the top of the central shaft, and it is characterized in that: the surface of the rotor is provided with a pre-compression point, and the gland is in contact with the pre-compression point, and the thickness of the rotor gradually becomes thinner from the center to the outside for elastic deformation; The rotor is a segmented stepped rotor with a square hole in the middle of the rotor. The inner upper surface of the rotor is a three-stage step, and the lower surface inside the rotor is a two-stage step. The thickness of the steps gradually becomes thinner from the center of the rotor to the outside; The rotor system also includes a stator and a motor base, the stator is installed on the motor base, the rotor, the gland, the central shaft, and the motor housing are sequentially installed on the stator, and they are all arranged concentrically. There is an adjusting gasket between them; The gland is detachably connected to the top of the central shaft, the gland is a concave circular plate with a center hole, and the central shaft is a round shaft with a shoulder. 2. The dust-proof traveling wave type ultrasonic motor pre-pressure rotor system according to claim 1, characterized in that: the gland and the central shaft are integrally formed. 3. The dust-proof traveling wave type ultrasonic motor pre-pressure rotor system according to claim 1, characterized in that: the outer upper surface of the gland is provided with a protruding first annular groove, and the outer diameter of the gland is the same as The diameter of the second step on the upper surface of the rotor is equal. 4. The dust-proof traveling wave type ultrasonic motor pre-pressure rotor system according to claim 3, characterized in that: the inner surface of the motor casing is provided with a protruding second annular groove. 5. The dust-proof traveling-wave type ultrasonic motor pre-pressure rotor system according to claim 4, characterized in that: after the motor is installed in the first annular groove and the second annular groove, the two annular grooves form a mutually fitting shape , forming a maze structure.