A multi-phase exciting rod type traveling wave ultrasonic motor

Abstract

The application discloses a multi-phase exciting vibrating rod type traveling wave ultrasonic motor and belongs to the technical field of ultrasonic motors. The motor specifically comprises a stator and a rotor. The stator is a circular tubular metal base. A plurality of positioning grooves are uniformly arranged on the outer periphery of the metal base along the axial direction. A piezoelectric ceramic stack is arranged in each positioning groove. Each piezoelectric ceramic stack is excited by a power supply of different phases to form an exciting unit. The polarization direction of the piezoelectric ceramic stack of each exciting unit is parallel to the axial direction of the stator. The stator is excited by the multi-phase piezoelectric ceramic stack, the mechanical power output during the vibration of the stator is effectively improved, the displacement of the stator end face under the non-resonance state is increased, the motor can also output mechanical power under the non-resonance state, the speed operation range of the motor is expanded, and the motor has the advantages of reasonable design, simple structure and easy implementation.

Description

Technical Field

[0001] The present invention relates to the technical field of ultrasonic motors, and in particular to a multi-phase excitation rod type traveling wave ultrasonic motor. Background Art

[0002] An ultrasonic motor (USM) utilizes the inverse piezoelectric effect of piezoelectric materials to induce micro-vibrations in the stator at ultrasonic frequencies, creating a specific motion trajectory on the stator surface and achieving electromechanical energy conversion through friction. Based on their driving principles, these motors are categorized as standing wave, traveling wave, and hybrid types. Traveling wave USMs utilize waves excited in the stator to induce elliptical vibrations on the surface of the elastic body.

[0003] Traditional rod-type ultrasonic motors typically use two power sources with a 90° phase difference to excite a piezoelectric ceramic disc. This causes the stator to generate two bending resonant modes with a 90° mechanical angle difference. This creates a rotating traveling wave on the stator end face, which in turn drives the rotor, which is pressed against the stator end face, to rotate. While these motors offer advantages such as a simple structure, high positioning accuracy, and immunity to external electromagnetic interference, they suffer from low output mechanical power and require operation in a stator resonant state, which limits the motor's speed range.

[0004] In view of this, the inventors of this case conducted in-depth research on the above-mentioned issues, which led to the creation of this case. Summary of the Invention

[0005] The object of the present invention is to provide a multi-phase excitation rod type traveling wave ultrasonic motor, which uses multiple piezoelectric stacks to excite the motor stator. Each piezoelectric ceramic stack is excited by a power supply with a different phase, which can increase the mechanical power output during stator vibration. At the same time, it can increase the displacement of the stator end face in a non-resonant state, thereby realizing the operation of the motor in the stator non-resonant state, thereby effectively expanding the motor's speed operating range.

[0006] In order to achieve the above object, the present invention adopts such technical solution:

[0007] A multiphase excitation rod-type traveling-wave ultrasonic motor includes a stator and a rotor. The stator is a tubular metal substrate. A plurality of positioning grooves are evenly arranged along the upper circumference of the metal substrate in the axial direction. A piezoelectric ceramic stack is installed in each of the positioning grooves. Each piezoelectric ceramic stack is excited by a power supply of a different phase to form an excitation unit. The polarization direction of the piezoelectric ceramic stack in each of the excitation units points toward the axis of the stator or away from the axis of the stator.

[0008] Furthermore, the phase difference between the excitation power supplies of two adjacent piezoelectric ceramic stacks is consistent with the angular phase difference between the installation of two adjacent positioning grooves.

[0009] Furthermore, voltage excitation is applied to the piezoelectric ceramic stack of each of the excitation units to stimulate symmetric vibration modes and antisymmetric vibration modes of the excitation unit, and each of the excitation units generates deformation displacement along the axis of the stator.

[0010] Furthermore, the stator is a hollow circular tubular metal matrix or a solid circular tubular metal matrix.

[0011] Furthermore, a friction layer is installed on the side of the rotor in contact with 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 against the rotor through the locking nut.

[0012] Furthermore, a counterweight is provided at one end of the stator away from the rotor.

[0013] Furthermore, one end of the stator close to the rotor is in a conical structure, and the end surface in contact with the rotor is in an arc structure.

[0014] Furthermore, a plurality of grooves are provided on the end surface of the stator in contact with the rotor.

[0015] By adopting the above-mentioned design scheme, the beneficial effects of the present invention are: by using a multi-phase piezoelectric ceramic stack to excite the stator, the mechanical power output during stator vibration is effectively improved, and at the same time, the displacement of the stator end face in a non-resonant state can be increased, so that the motor can also output mechanical power in a non-resonant state, and at the same time, the speed operating range of the motor is expanded. The present invention has the advantages of reasonable design, simple structure, and easy implementation. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of the present invention;

[0017] Figure 2 is a cross-sectional view of the present invention;

[0018] In the figure: stator 1, piezoelectric ceramic stack 2, rotor 3, friction layer 4, counterweight 5, groove 6. DETAILED DESCRIPTION

[0019] The following is a clear and complete description of the technical solutions in the embodiments of the present invention, in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts are within the scope of protection of the present invention.

[0020] Reference Figures 1 to 2 :

[0021] A multi-phase excitation rod type traveling wave ultrasonic motor comprises a stator 1 and a rotor 3. The stator 1 is a hollow tubular metal matrix or a solid tubular metal matrix. Preferably, in this embodiment, the stator 1 is a hollow tubular metal matrix.

[0022] Several positioning grooves are evenly arranged along the axial direction of the outer periphery of the metal substrate. A piezoelectric ceramic stack 2 is installed in each positioning groove. The piezoelectric ceramic stack 2 is bonded and fixed to the positioning groove of the metal substrate by an adhesive.

[0023] Each piezoelectric ceramic stack 2 is excited by a power source with different phases, forming an excitation unit. The polarization direction of the piezoelectric ceramic stack 2 in each excitation unit is aligned with the axis of the stator 1. Voltage excitation is applied to the piezoelectric ceramic stack 2 of each excitation unit via a wire, stimulating the unit's symmetric and antisymmetric vibration modes. Each excitation unit produces a deformation displacement along the axis of the stator 1. It should be noted that the number of sections of the piezoelectric ceramic stack 2 is designed based on actual needs, depending on the diameter of the stator 1 and the number of waveforms in the stator 1. By designing piezoelectric ceramic stacks 2 with different phases and applying modes at different phases, a variety of vibration modes can be achieved to adapt to different operating conditions and load variations, greatly expanding the application range and adaptability of the motor. This design generates stronger vibration and driving force, resulting in higher output power, speed, and precision, making it suitable for high-end equipment and precision instruments with high motor performance requirements.

[0024] Furthermore, a friction layer 4 is installed on the side of the rotor 3 that contacts the stator 1, and a spring (not shown in the figure), a pressure cover (not shown in the figure) and a locking nut (not shown in the figure) are provided on the side of the rotor 3 away from the stator 1. The spring and the pressure cover are pressed against the rotor 3 through the connection between the locking nut and the rotating shaft.

[0025] Furthermore, a counterweight 5 is provided at one end of the stator 1 away from the rotor 3 .

[0026] Furthermore, the end of the stator 1 close to the rotor 3 is a conical structure, and the end face in contact with the rotor 3 is an arc-shaped structure. The end face of the stator 1 in contact with the rotor 3 is provided with a plurality of grooves 6. The setting of the grooves 6 is conducive to amplifying the amplitude of the inner and outer peripheral surfaces of the metal matrix of the annular stator 1 in the circumferential direction, and the grooves 6 accommodate fine chips generated by friction during the operation of the ultrasonic motor and play a heat dissipation role.

[0027] Furthermore, the phase difference between the excitation power supplies of two adjacent piezoelectric ceramic stacks 2 is consistent with the angular phase difference between the installations of two adjacent positioning grooves.

[0028] Preferably, in this embodiment, six positioning grooves are evenly distributed on the outer periphery of the stator 1 , and a piezoelectric ceramic stack 2 is adhered in each positioning groove.

[0029] The excitation method of the piezoelectric ceramic stack 2 is as follows: a piezoelectric ceramic stack 2 with a polarization direction identical to the axial direction of the stator 1 is pasted on each of six rectangular planes of equal size, and a sinusoidal excitation signal is applied to the piezoelectric ceramic stack 2, thereby inducing a longitudinal vibration mode of the motor stator 1, causing the piezoelectric ceramic stack 2 to deform and displace along the axis of the stator 1.

[0030] In general, the multi-phase excitation rod-type traveling wave ultrasonic motor provided by the present invention can realize multi-phase traveling wave excitation of the end face of the motor stator 1, improve the mechanical power output when the stator 1 vibrates, and at the same time increase the displacement of the end face of the stator 1 in a non-resonant state, thereby expanding the applicable range of the excitation frequency. It is suitable for applications with high power, high resolution and a wide speed range, and has high practical value.

[0031] It should be noted that, in this document, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Although the embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A multiphase exciter-type traveling-wave ultrasonic motor comprising a stator and a rotor, characterized in that: The stator is a tubular metal substrate, and a plurality of positioning grooves are evenly arranged along the axial direction of the outer periphery of the metal substrate. 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 axial direction of the stator. The phase difference between the excitation power supplies of two adjacent piezoelectric ceramic stacks is consistent with the angular phase difference between the installation of two adjacent positioning grooves; The piezoelectric ceramic stack of each of the excitation units is applied with a voltage excitation for exciting the symmetric vibration mode and the antisymmetric vibration mode of the excitation unit, and each of the excitation units generates a deformation displacement along the axis of the stator; The stator is a hollow tubular metal matrix or a solid tubular metal matrix; 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 against the rotor through the locking nut.

2. The multi-phase exciter-type traveling-wave ultrasonic motor according to claim 1, characterized in that: A counterweight is provided at one end of the stator away from the rotor.

3. The multi-phase exciter-type traveling-wave ultrasonic motor according to claim 1, characterized in that: One end of the stator close to the rotor is in a conical structure, and the end surface in contact with the rotor is in an arc structure.

4. The multi-phase exciter-type traveling-wave ultrasonic motor according to claim 1, characterized in that: The end surface of the stator in contact with the rotor is provided with a plurality of grooves.

Images