CN203406800U - Single Excitation Rotary Ultrasonic Motor - Google Patents

Abstract

The utility model discloses a single excitation rotary ultrasonic motor. The single excitation rotary ultrasonic motor is characterized in that a rotor comprises a turntable and a frictional layer arranged on the surface of the turntable, and a stator comprises an ultrasonic vibration energy transducer, an elliptical vibration mode converter and a friction driving block arranged at the front end of the elliptical vibration mode converter; the elliptical vibration mode converter is arranged at the front end of the ultrasonic vibration energy transducer, is an inclined wedge structure, can transform the longitudinal ultrasonic vibration generated by the ultrasonic vibration energy transducer into the longitudinal-flexural composite ultrasonic elliptical vibration at the tail end of the elliptical vibration mode converter and the friction driving block, and drives the rotor to carry out continuous and rotary motion.

Description

Single Excitation Rotary Ultrasonic Motor

technical field

The utility model relates to the field of ultrasonic motors utilizing the inverse piezoelectric effect of piezoelectric ceramics, in particular to a single-excitation rotary ultrasonic motor.

Background technique

The rotary ultrasonic motor is a new type of micro-motor developed and applied rapidly in the 1980s. It is an electromechanical coupling device that uses the inverse piezoelectric effect of piezoelectric materials to convert electrical energy to mechanical energy. Through the friction between the stator and the rotor, the The micro-vibration of the elastomer is converted into the macro-rotational motion of the rotor, which directly pushes the load. Because of its small size, light weight, low speed and high torque, low noise, fast response, high positioning accuracy, no electromagnetic interference and strong environmental adaptability, it has been increasingly widely used in medical, aerospace, robotics, MEMS and other technical fields. Applications.

In the existing rotary ultrasonic motors, the out-of-plane bending vibration mode is mainly combined into end-face traveling waves, and the rotor is driven to rotate. The common problems are small driving torque, large axial volume, and wear difference between the inner and outer diameter contact areas of the stator and rotor. In addition, even if the in-plane vibration mode is adopted, in order to apply the in-plane radial preload, the disc or ring of the vibrator or rotor is made into two semi-discs or semi-circles, and the middle passes through The springs are connected into discs or rings to apply in-plane radial preload. At present, it is also difficult to achieve high torque, and the work reliability is low. In the patent document with the publication number CN101030740A and the invention name "Single-phase Driven Bending Rotary Ultrasonic Motor", a single-phase drive standing wave rotating ultrasonic motor with a tapered body structure is disclosed. The axially stacked piezoelectric ceramic sheets excite the vibration of the stator, and the six piezoelectric ceramic sheets are fixed on the central shaft by means of compression nuts and pressure shaft sleeves. Although the motor has the advantages of large output torque, the six piezoelectric ceramic sheets of the motor must be staggered and installed by 60 degrees according to the polarization partition, and its structure is complicated. Spiral motion (rotational force) can easily cause misalignment between piezoelectric ceramic sheets, and it is difficult to ensure the technical requirement of 60 degrees of misalignment between adjacent piezoelectric ceramic sheets; in addition, there is no positioning device between the stator and rotor of the motor, which The accuracy of the contact position between the stator and the rotor is affected, which in turn affects the stability of the torque and speed of the motor; therefore, this type of rotating ultrasonic motor has a complex structure and requires high contact position accuracy between the stator and the rotor. It is difficult to manufacture and install, and the stability of motor torque and speed is poor.

Contents of the invention

The utility model provides a novel single-excitation rotary ultrasonic motor, aiming at overcoming the deficiencies in the above-mentioned rotary ultrasonic motor.

The single-excitation rotary ultrasonic motor includes a stator and a rotor, the rotor includes a turntable and a friction layer arranged on the surface of the turntable; the stator includes an ultrasonic vibration transducer, an elliptical vibration mode converter and a friction drive block; the ultrasonic vibration transducer The outer contour is cylindrical, which includes bolts and the rear cover plate, piezoelectric ceramic sheet, electrode sheet and front cover plate that are sequentially sleeved on the bolts. The front cover plate is provided with a flange that can be connected with other structural devices. , the rear cover and the front cover connect and compress the rear cover, piezoelectric ceramic sheet, electrode sheet and front cover through bolts, forming the energy conversion part of the single-excitation rotary ultrasonic motor, which converts the ultrasonic electric energy output by the ultrasonic power supply is the ultrasonic vibration energy of the ultrasonic transducer.

The elliptical vibration mode converter and the front cover are made as a whole and arranged on the front end of the front cover, or an additional connecting stud is used to connect the elliptical vibration mode converter to the front end of the front cover, and the elliptical vibration The mode converter is an oblique wedge structure. The oblique wedge structure elliptical vibration mode converter is originally a cuboid as a whole, and a part of one side is cut off along the axial direction of the ultrasonic vibration transducer to form an oblique wedge structure, forming two oblique wedges. Among the sides, the uncut side is parallel to the axis of the ultrasonic vibration transducer, and the other side that has been cut is at an angle of 3-30 degrees to the axis of the ultrasonic vibration transducer.

The purpose of making the elliptical vibration mode converter form an oblique wedge structure is to change the vibration mode of the ultrasonic vibration transducer so that the frequency of the longitudinal vibration mode and the frequency of the bending vibration mode are close to or equal, because the elliptical vibration mode of the oblique wedge structure Due to the existence of the mode converter, the longitudinal ultrasonic vibration generated by the ultrasonic vibration transducer is decomposed into a part of the longitudinal vibration component and a part of the The bending vibration component, and the two vibration components have a certain phase difference, and then compound at the end of the oblique wedge structure elliptical vibration mode converter to form an elliptical trajectory vibration.

The friction driving block is arranged on the front end of the elliptical vibration mode converter through welding, bonding or screw connection, and the friction driving block is in contact with the friction layer on the turntable. The flange of the ultrasonic vibration transducer is used to install the stator and the pre-pressure device. The stator and the rotor are connected as a whole to form a single-excitation rotary ultrasonic motor. The angle is 20 degrees to 160 degrees.

When the ultrasonic electrical signal output by the ultrasonic power supply is connected to the electrode sheet of the ultrasonic vibration transducer, the ultrasonic vibration transducer generates ultrasonic vibration, and the ultrasonic vibration energy is transmitted from the ultrasonic vibration transducer to the end of the elliptical vibration mode converter , which is converted into longitudinal-bending composite ultrasonic elliptical vibration with a certain phase difference combined with longitudinal vibration and bending vibration, that is, converted into longitudinal-bending composite ultrasonic elliptical vibration at the end of the elliptical vibration mode converter; and drives the friction drive block and elliptical vibration mode The ends of the converter make ultrasonic elliptical vibration together, and then drive the rotor for continuous rotation. Compared with the single-excitation rotary ultrasonic motor introduced in the existing literature, the rotary ultrasonic motor has the advantages of large power capacity, high energy conversion efficiency, simple structure, easy manufacture, low cost, high structural rigidity, simple control drive system and stable vibration performance. .

Furthermore, the single-excitation rotary ultrasonic motor has only one set of longitudinally vibrating piezoelectric ceramic sheets.

Furthermore, the single-excitation rotary ultrasonic motor only needs to be excited by one ultrasonic electric signal.

The utility model adopts the mechanical vibration mode conversion mechanism to convert the longitudinal vibration of the ultrasonic transducer into the longitudinal bending composite ultrasonic elliptical vibration of the elliptical vibration mode converter, simplifies the overall structure of the single-excitation rotary ultrasonic motor, and greatly reduces the vibration The complexity of the system reduces the difficulty of manufacturing and assembly and production costs. The entire single-excitation rotary ultrasonic motor has a simple structure and is easy to manufacture, which is conducive to the realization of the miniaturization goal; in addition, the utility model only needs one control circuit and an ultrasonic electrical signal for excitation. , the control difficulty is low, avoiding the complex ultrasonic power supply development cost of two-phase or multi-phase ultrasonic vibration compound to form an elliptical vibration transducer, simplifying the control circuit and ultrasonic power supply structure, reducing the cost of control circuit and ultrasonic power supply, and reducing the control cost. The size of the circuit and ultrasonic power supply is easy to realize the miniaturization and integration of the control circuit and ultrasonic power supply, which improves the reliability, the working performance is more stable, and the application prospect is broad.

Description of drawings

Fig. 1 is a structural representation of the utility model.

Fig. 2 is a schematic diagram of an application example of the utility model.

Explanation of symbols in the figure: 1. Bolt, 2. Rear cover, 3. Piezoelectric ceramic sheet, 4. Electrode sheet, 5. Front cover, 6. Flange, 7. Elliptical vibration mode converter, 8. Turntable, 9. friction layer, 10 friction drive block, 11. ultrasonic power supply

Detailed ways

As shown in Figures 1 and 2, a single-excitation rotary ultrasonic motor includes a stator and a rotor, the rotor includes a turntable 8 and a friction layer 9 bonded to the surface of the turntable 8; the stator includes an ultrasonic vibration transducer, an elliptical vibration mode converter 6 and a friction drive block 10; the outer contour of the ultrasonic vibration transducer is cylindrical, which includes a bolt 1 and a back cover 2, a piezoelectric ceramic sheet 3, an electrode sheet 4 and a front cover 5 that are sequentially sleeved on the bolt 1, The front cover 5 is provided with a flange 6 that can be connected with other structural devices. The rear cover 2 and the front cover 5 connect the rear cover 2, the piezoelectric ceramic sheet 3, the electrode sheet 4 and the front cover through bolts 1. The plates 5 are connected and compressed to form the energy conversion part of the single-excitation rotary ultrasonic motor, which converts the ultrasonic electric energy output by the ultrasonic power supply 11 into the ultrasonic vibration energy of the ultrasonic vibration transducer. The single-excitation rotary ultrasonic motor has only one set of longitudinal vibration piezoelectric ceramic sheets 3, the diameter of the piezoelectric ceramic transducer section is 30mm, the material of the piezoelectric ceramic sheet 3 is PZT-8, and the size is: Ф30mm×Ф15mm×5mm , piezoelectric ceramic The number of ceramic sheets 3 is two.

The elliptical vibration mode converter 7 and the front cover 5 are made into an integral part and arranged on the front end of the front cover 5. The elliptical vibration mode converter 7 has a wedge-shaped structure as a whole, and the elliptical vibration mode converter with the wedge-shaped structure is the original whole It is a cuboid with a cross-sectional side length of 15 × 15mm and a length of 40mm. One side is cut off along the axial direction of the ultrasonic vibration transducer to form a wedge-shaped structure. Among the two sides of the wedge shape, the side that is not cut Parallel to the axis of the ultrasonic vibration transducer, the other cut side is at an angle of 10 degrees to the axis of the ultrasonic vibration transducer.

The friction driving block 10 is arranged on the front end of the elliptical vibration mode converter 7 by bonding, and the friction driving block 10 is in contact with the friction layer 9 on the turntable 8 . Use the flange of the ultrasonic vibration transducer to install the stator and the pre-pressure device, connect the stator and the rotor as a whole to form a single-excitation rotary ultrasonic motor, and the axis of the ultrasonic vibration transducer fixed by the flange is aligned with the plane of the turntable 8 The included angle is 45 degrees.

The natural frequency of the stator of the single-excitation rotary ultrasonic motor is 25.32KHz, the impedance is 86 ohms, and the dynamic resistance is 17 ohms. It only needs to be excited by one ultrasonic electric signal. The output voltage range of the ultrasonic power supply 11 is 0-400V, and the current range is 0-4A. The output frequency is 25.32±0.01KHz, and the ultrasonic power supply 11 has an automatic frequency tracking function within the specified frequency range.

When the ultrasonic electrical signal output by the ultrasonic power supply is connected to the electrode sheet 4 of the ultrasonic vibration transducer, the ultrasonic vibration transducer generates ultrasonic vibration, and the ultrasonic vibration energy is transmitted from the ultrasonic vibration transducer to the elliptical vibration mode converter 7 After the end, it is converted into longitudinal and bending composite ultrasonic elliptical vibration with a certain phase difference, which is converted into longitudinal and bending composite ultrasonic elliptical vibration at the end of the elliptical vibration mode converter 7; and drives the friction drive block 10 and The ends of the elliptical vibration mode converter 7 together perform ultrasonic elliptical vibration, and then drive the rotor to perform continuous rotational motion. After running for 10 minutes, the system reaches a stable working state. The output voltage of the ultrasonic power supply 11 is 240V, the current is 1.45A, and the peak peripheral velocity of the turntable 8 with a diameter of 40mm is 56.2mm/s.

Claims (6)

1. single stimulated rotation ultrasonic motor, comprises rotor and stator, it is characterized in that: rotor comprises rotating disk and is arranged on the frictional layer of disc surfaces; Stator comprises ultrasonic vibration transducer, elliptical vibration MODAL TRANSFORMATION OF A device and friction-driven piece; Described ultrasonic vibration transducer outline is cylindrical, it comprises bolt and is set in successively back shroud, piezoelectric ceramic piece, electrode slice and the front shroud on bolt, on front shroud, be provided with and can connect with other constructional device the ring flange of use, back shroud and front shroud are connected back shroud, piezoelectric ceramic piece, electrode slice and front shroud to compress by bolt; Described elliptical vibration MODAL TRANSFORMATION OF A device is arranged on the front end of front shroud, for inclined wedge-shaped structure, the former integral body of inclined wedge-shaped structure elliptical vibration MODAL TRANSFORMATION OF A device is cuboid, after being cut a part, ultrasonic vibration transducer axis direction one side forms inclined wedge-shaped structure, form in two sides of inclined wedge-shaped, a cut parallel sided is not in ultrasonic vibration transducer axis, and the another side being cut becomes 3-30 degree angle with ultrasonic vibration transducer axis; Described friction-driven piece is arranged on the front end of elliptical vibration MODAL TRANSFORMATION OF A device; Ultrasonic vibration transducer axis after ring flange is fixing and the angle of plane of rotor disc are 20 degree ~ 160 degree.

2. single stimulated rotation ultrasonic motor according to claim 1, is characterized in that: described elliptical vibration MODAL TRANSFORMATION OF A device and front shroud are made into a whole installation at the front end of front shroud.

3. single stimulated rotation ultrasonic motor according to claim 1, is characterized in that: also comprise that connects a double-screw bolt, for elliptical vibration MODAL TRANSFORMATION OF A device being connected in to the front end of front shroud.

4. according to the single stimulated rotation ultrasonic motor described in claim 1 or 2 or 3, it is characterized in that: described friction-driven piece is arranged on the front end of elliptical vibration MODAL TRANSFORMATION OF A device by welding.

5. according to the single stimulated rotation ultrasonic motor described in claim 1 or 2 or 3, it is characterized in that: described friction-driven piece is by the bonding front end that is arranged on elliptical vibration MODAL TRANSFORMATION OF A device.

6. according to the single stimulated rotation ultrasonic motor described in claim 1 or 2 or 3, it is characterized in that: also comprise a joint bolt, for friction-driven piece being connected in to the front end of elliptical vibration MODAL TRANSFORMATION OF A device.

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