Stator double-sided excitation traveling wave rotary ultrasonic motor

Abstract

The application discloses a kind of stator double-face excitation row wave type rotary ultrasonic motor, belong to ultrasonic motor technical field, specifically including base, stator and rotor, stator includes cylinder wall and cylinder bottom, stator has upper end and lower end, cylinder bottom has upper side and lower side, upper side and lower side are provided with several positioning grooves, each positioning groove is equipped with piezoelectric ceramic stack, each piezoelectric ceramic stack is excited by different phase power supply, forms an excitation unit, the polarization direction of piezoelectric ceramic stack of each excitation unit is parallel to the circumferential direction of stator;The application is provided with several piezoelectric ceramic stacks on upper side and lower side, and simultaneously excitation is carried out to upper side and lower side, each piezoelectric ceramic stack is excited by corresponding phase power supply, effectively increase the input power of motor, and then improve the mechanical power output by stator when vibrating, the application can realize the operation of stator under non-resonance state, and then expand the speed operating range of motor.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ultrasonic motor, in particular to a stator double-surface excitation traveling wave type rotary ultrasonic motor. BACKGROUND

[0002] The ultrasonic motor is a new type of motor which utilizes the inverse piezoelectric effect of piezoelectric material to excite the micro-vibration of the stator in the ultrasonic frequency band, so as to form a specific movement track on the surface of the stator and realize the conversion of mechanical energy and electrical energy through friction. According to the driving principle of the ultrasonic motor, it can be divided into several types such as standing wave type ultrasonic motor, traveling wave type ultrasonic motor and composite type ultrasonic motor. Among them, the traveling wave type ultrasonic motor utilizes the traveling wave excited in the stator to make the elastic body driving surface particles obtain elliptical track vibration with driving effect.

[0003] The traditional traveling wave type rotary ultrasonic motor usually adopts equal-amplitude alternating voltage signals with a phase difference of 90° in the ultrasonic frequency band to excite two groups of piezoelectric ceramic sheets which are pasted on the bottom of the disc type stator and have a spatial position difference of 1 / 4 of the wavelength of the traveling wave. Then, two standing waves with a time difference of 90° electrical angle and a spatial difference of 90° mechanical angle are generated in the stator. The two standing waves are finally combined into a traveling wave propagating along the circumference of the stator on the side surface of the stator. Finally, the rotor is rotated through friction to output mechanical power. This type of motor has the advantages of simple structure, fast response speed, high positioning accuracy, no electromagnetic radiation and no external electromagnetic interference. The above-mentioned traveling wave type rotary ultrasonic motor has the disadvantage of small output mechanical power, and the stator needs to work in the resonance state, so the speed range of the motor is also greatly limited.

[0004] Therefore, the present application is produced based on the in-depth research on the above problems by the present inventor. SUMMARY

[0005] The present application aims to provide a stator double-surface excitation traveling wave type rotary ultrasonic motor which uses multiple piezoelectric stacks to excite the stator. Each piezoelectric ceramic stack is excited by power sources with different phases, which can improve the output mechanical power of the stator vibration, increase the displacement of the stator side surface in the non-resonance state, realize the operation of the motor in the non-resonance state of the stator, and effectively expand the speed operating range of the motor.

[0006] In order to achieve the above-mentioned purpose, the present application adopts the following technical scheme:

[0007] The utility model provides a kind of stator double-sided excitation row wave type rotary ultrasonic motor, including base, stator and rotor, the stator is cylindrical structure, the stator includes integrally connected cylinder wall and cylinder bottom, and the stator has upper end and lower end, the cylinder bottom has upper side and lower side, the stator is arranged above the base, the upper end is connected with the rotor, the upper side and the lower side of the cylinder bottom are all provided with several positioning grooves, each positioning groove is mounted with piezoelectric ceramic stack, each piezoelectric ceramic stack is excited by different phase power supply, forms an excitation unit, the polarization direction of the piezoelectric ceramic stack of each excitation unit is parallel with the circumferential direction of the stator, the base extends upwards along the direction of the stator and has positioning step, the lower end is provided with recess matched with the positioning step corresponding the position of the positioning step, and the positioning step is matched with the recess.

[0008] Further, the piezoelectric ceramic stack of each excitation unit is excited by voltage, to excite symmetric vibration mode and antisymmetric vibration mode of the excitation unit, and each excitation unit is deformed and displaced along the circumferential direction of the stator.

[0009] Further, the positioning grooves of the upper side and the positioning grooves of the lower side are both 2n, n is a natural number greater than or equal to 1.

[0010] Further, the adjacent two piezoelectric ceramic stacks of the upper side and the adjacent two piezoelectric ceramic stacks of the lower side are a group, and the corresponding upper side and lower side are evenly divided into n regions along the circumferential direction, and the length of each region along the circumferential direction is one row wave wavelength.

[0011] Further, the n groups of piezoelectric ceramic stacks evenly arranged on the lower side are spaced apart from the n groups of piezoelectric ceramic stacks evenly arranged on the upper side by a distance of 1 / 4 row wave wavelength along the circumferential direction in space.

[0012] Further, the piezoelectric ceramic stacks are excited by alternating current power supply with the same amplitude and frequency, the excitation power supply phases of the adjacent two piezoelectric ceramic stacks arranged on the same side of the cylinder bottom are different by 180°, and the excitation power supply phases of the piezoelectric ceramic stacks of the upper side and the piezoelectric ceramic stacks of the lower side are different by 90°.

[0013] Further, the side of the rotor in contact with the stator is provided with a friction layer, and the side of the rotor away from the stator is provided with a spring, a gland and a locking nut, and the spring, the gland and the locking nut are coupled and pressed on the rotor.

[0014] Further, a plurality of tooth grooves are evenly arranged on the cylinder wall along the circumferential direction.

[0015] Further, the base and the rotor are hollow and / or solid structures, and the stator is a hollow structure.

[0016] By adopting the foregoing design scheme, the application has the advantages that: by arranging a plurality of piezoelectric ceramic stacks on the upper side and the lower side and simultaneously exciting the upper side and the lower side of the stator, each piezoelectric ceramic stack is excited by a power supply of a corresponding phase, the input power of the motor is effectively increased, and the mechanical power output by the stator when vibrating is improved; meanwhile, compared with a conventional piezoelectric ceramic sheet, the piezoelectric ceramic stack has a larger displacement deformation under the excitation of the same amplitude voltage, and therefore, the stator can run in a non-resonance state, and the speed operating range of the motor is expanded. BRIEF DESCRIPTION OF DRAWINGS

[0017] Fig. 1 is a structural schematic view of the application;

[0018] Fig. 2 is a sectional view of the application;

[0019] In the figure: base 1, positioning step 11, stator 2, upper end 21, lower end 22, recess 221, cylinder wall 23, tooth groove 231, cylinder bottom 24, upper side 241, lower side 242, positioning groove 243, piezoelectric ceramic stack 3, rotor 4, friction layer 5. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the application will be apparently and completely described below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the application.

[0021] Reference Figs. 1-2 :

[0022] A stator double-surface excitation traveling wave type rotary ultrasonic motor, comprising a base 1, a stator 2 and a rotor 4, the stator 2 comprises an integrally connected cylinder wall 23 and cylinder bottom 24, and the stator 2 has an upper end 21 and a lower end 22, the cylinder bottom 24 has an upper side 241 and a lower side 242, the stator 2 is arranged above the base 1, and the upper end 21 is in contact with the rotor 4. Further, the stator 2 is in a cylindrical hollow structure, the base 1 and the rotor 4 are hollow and / or solid structures, the base 1 extends upward along the direction of the stator 2 and has a positioning step 11, the lower end 22 is provided with a recess 221 matched with the positioning step 11 at the position corresponding to the positioning step 11, and the positioning step 11 is matched with the recess 221. Preferably, in the embodiment, the base 1 and the rotor 4 adopt a hollow metal matrix.

[0023] The upper side surface 241 and the lower side surface 242 are each provided with a plurality of positioning grooves 243, and each of the positioning grooves 243 is mounted with a piezoelectric ceramic stack 3 which is fixed by adhesive with the positioning groove 243 of the stator 2. Each piezoelectric ceramic stack 3 is excited by power supplies of different phases to form an excitation unit, and the polarization direction of the piezoelectric ceramic stack 3 of each excitation unit is parallel to the circumferential direction of the stator 2. The piezoelectric ceramic stack 3 of each excitation unit is excited by voltage through a wire, which is used to excite the symmetric vibration mode and the anti-symmetric vibration mode of the excitation unit, and each excitation unit produces a deformation displacement along the circumferential direction of the stator 2. The upper side surface 241 and the lower side surface 242 of the stator are excited at the same time, which effectively improves the input power of the motor, and in turn can improve the mechanical power output by the motor when vibrating. At the same time, using the piezoelectric ceramic stack 3 as the excitation unit can effectively improve the deformation amount of the stator 2 under the same amplitude voltage excitation, realize the output of mechanical power by the motor in the non-resonant state, widen the speed operating range of the motor, and fully utilize the space of the stator 2. It has the advantages of reasonable design, clear structure and easy implementation. It needs to be explained that the design of piezoelectric ceramic stacks 3 of different phases can realize various vibration modes by applying different phase modes, so as to adapt to different working conditions and load changes, greatly expand the application range and adaptability of the motor. It can produce stronger vibration and driving force, so as to make the motor have higher output power, speed and precision, and is suitable for high-end equipment and precision instruments with high requirements on motor performance.

[0024] Further, the positioning grooves 243 of the upper side surface 241 and the positioning grooves 243 of the lower side surface 242 are each 2n, and n is a natural number greater than or equal to 1. The adjacent two piezoelectric ceramic stacks 3 of the upper side surface 241 and the adjacent two piezoelectric ceramic stacks 3 of the lower side surface 242 are each a group, and the corresponding upper side surface 241 and lower side surface 242 are evenly divided into n regions along the circumferential direction, and the length of each region along the circumferential direction is one wavelength of a traveling wave.

[0025] The n groups of piezoelectric ceramic stacks 3 evenly arranged on the lower side surface 242 are spaced apart from the n groups of piezoelectric ceramic stacks 3 evenly arranged on the upper side surface 241 by a distance of 1 / 4 wavelength of a traveling wave in space along the circumferential direction.

[0026] The piezoelectric ceramic stacks 3 are excited by AC power supplies of the same amplitude and frequency, the excitation power supplies of the adjacent two piezoelectric ceramic stacks 3 arranged on the same side of the barrel bottom 24 are 180° out of phase, and the excitation power supplies of the piezoelectric ceramic stacks 3 of the upper side surface 241 and the piezoelectric ceramic stacks 3 of the lower side surface 242 are uniformly 90° out of phase.

[0027] Further, the side of the rotor 4 contacting the stator 2 is provided with a friction layer 5, and the side of the rotor 4 away from the stator 2 is provided with a spring (not shown in the figure), a gland (not shown in the figure) and a lock nut (not shown in the figure), the spring and the gland being coupled and pressed on the rotor 4 by the lock nut.

[0028] The cylinder wall 23 is uniformly provided with a plurality of tooth grooves 231 in the circumferential direction, which can effectively amplify the deformation of the stator 2, and the tooth grooves 231 can accommodate the debris generated by friction, thereby improving the stability of the motor during operation.

[0029] It is to be noted that the relational terms herein such as first and second and the like are used solely to distinguish one from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. While the embodiments of the application have been illustrated and described, it will be understood by those of ordinary skill in the art that various changes, modifications, alternatives, and variations can be made to the embodiments without departing from the spirit and scope of the application, which is defined by the following claims and their equivalents.

Claims

1. A traveling wave rotary ultrasonic motor with double-sided stator excitation, comprising a base, a stator, and a rotor, characterized in that: The stator has a cylindrical structure, and includes a cylindrical wall and a cylindrical bottom connected as an integral part. The stator has an upper end and a lower end, and the cylindrical bottom has an upper side and a lower side. The stator is arranged above the base, and the upper end is connected to the rotor. The upper side and the lower side of the cylindrical bottom are both provided with a plurality of positioning grooves, and a piezoelectric ceramic stack is installed in each of the positioning grooves. Each piezoelectric ceramic stack is excited by a power supply of different phases to form an excitation unit. The polarization direction of the piezoelectric ceramic stack of each excitation unit is parallel to the circumferential direction of the stator. The base extends upward along the direction of the stator with a positioning step, and the lower end is provided with a groove matching the positioning step at a position corresponding to the positioning step, and the positioning step is adapted to the groove.

2. The stator double-sided excitation traveling wave type rotary ultrasonic motor according to claim 1, characterized in that: Voltage excitation is applied to the piezoelectric ceramic stack of each of the excitation units to excite a symmetric vibration mode and an antisymmetric vibration mode of the excitation unit, and each of the excitation units is deformed and displaced along the circumferential direction of the stator.

3. The stator double-sided excitation traveling wave type rotary ultrasonic motor according to claim 1, characterized in that: The number of the positioning grooves on the upper side and the number of the positioning grooves on the lower side are both 2n, where n is a natural number greater than or equal to 1.

4. The stator double-sided excitation traveling wave type rotary ultrasonic motor according to claim 3, characterized in that: The two adjacent piezoelectric ceramic stacks on the upper side and the two adjacent piezoelectric ceramic stacks on the lower side are each a group, and the corresponding upper side and lower side are evenly divided into n areas along the circumferential direction, and the length of each area along the circumferential direction is one traveling wave wavelength.

5. The stator double-sided excitation traveling wave type rotary ultrasonic motor according to claim 4, characterized in that: The n groups of piezoelectric ceramic stacks uniformly arranged on the lower side are spatially spaced apart from the n groups of piezoelectric ceramic stacks uniformly arranged on the upper side by a distance of 1 / 4 of the wavelength of the traveling wave along the circumferential direction.

6. The stator double-sided excitation traveling wave type rotary ultrasonic motor according to claim 4, characterized in that: The piezoelectric ceramic stacks are excited by an AC power supply of the same amplitude and frequency. The phases of the excitation power supplies of two adjacent piezoelectric ceramic stacks arranged on the same side of the bottom of the cylinder are 180° apart, and the phases of the excitation power supplies of the piezoelectric ceramic stacks on the upper side and the piezoelectric ceramic stacks on the lower side are uniformly 90° apart.

7. The stator double-sided excitation traveling wave type rotary ultrasonic motor according to claim 4, characterized in that: A friction layer is installed on the side of the rotor that contacts the stator, and a spring, a pressure cover and a locking nut are provided on the side of the rotor away from the stator. The spring and the pressure cover are connected and pressed onto the rotor through the locking nut.

8. The stator double-sided excitation traveling wave type rotary ultrasonic motor according to claim 1, characterized in that: A plurality of tooth grooves are evenly arranged on the cylinder wall along the circumferential direction.

9. The stator double-sided excitation traveling wave type rotary ultrasonic motor according to claim 1, characterized in that: The base and the rotor are hollow and / or solid structures, and the stator is a hollow structure.

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