CN203406801U - Rotary Ultrasonic Motor Driven by Single Electric Signal - Google Patents

Abstract

The utility model discloses a single electric signal driving rotary ultrasonic motor. The single electric signal driving rotary ultrasonic motor comprises a mandrel, and a back cover plate, piezoelectric ceramic pieces, electrode slices, an elliptical vibration mode converter, a friction disc, a bearing, a spring and a nut which are sleeved on the mandrel orderly. The mandrel, the back cover plate, the piezoelectric ceramic pieces, the electrode slices and the elliptical vibration mode converter form a stator part of the ultrasonic motor, the friction disc and the bearing form a rotor part of the ultrasonic motor, and the spring and the nut form a positive pressure pre-tightening force adjusting mechanism of the rotor part and the stator part of the ultrasonic motor. The single electric signal driving rotary ultrasonic motor of the utility model realizes the elliptical orbit motion of the mass points on the end faces of the driving teeth of the stator by utilizing the specially designed elliptical vibration mode converter and by the longitudinal vibration of the set of piezoelectric ceramic pieces, and drives the rotor to rotate. The single electric signal driving rotary ultrasonic motor of the utility model has the advantages of being simple in structure, low in cost and small in control difficulty, being easy to manufacture, miniaturize and integrate, etc., and is wide in application prospect.

Description

Rotary Ultrasonic Motor Driven by Single Electric Signal

technical field

The utility model relates to the field of ultrasonic motors utilizing the inverse piezoelectric effect of piezoelectric ceramics, in particular to a rotary ultrasonic motor driven by a single electric signal.

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. In the existing rotary ultrasonic motors, there are generally problems such as small driving torque, large axial volume, large wear difference between the inner and outer diameter contact areas of the stator and rotor, and low working reliability.

The mode conversion ultrasonic motor driven by a single electric signal is also a kind of ultrasonic motor. It is driven by a group of piezoelectric ceramic elements, and the stator generates complex vibration with two vibration modal components through a mode converter with a special structure. . If there is a certain phase difference between the two vibration modes and the frequency is similar, the end surface particle of the stator on the contact interface between the stator and the rotor will generate an elliptical trajectory vibration, thereby obtaining the motion and torque of the rotor through the friction between the stator and the rotor .

In the patent document with the publication number CN101860259A and the invention name "Single Electric Signal Excited Rotary Ultrasonic Motor", a method is disclosed that uses a window-shaped dislocation mode converter to convert the longitudinal vibration generated by the sandwich vibrator into the elliptical vibration of the driving tooth point. , and then drive the ultrasonic motor to rotate the rotor. The control and drive system of the invention is simple and easy to assemble, but the manufacturing of the window-shaped dislocation mode converter is difficult and the production cost is high, which restricts its promotion and application in industrial production.

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, etc., its structure is complicated, and the screw movement (rotation force) of the compression nut during the compression process of the piezoelectric ceramic sheets is very easy to cause misalignment between the piezoelectric ceramic sheets, which is difficult to achieve. The technical requirement to ensure a 60-degree misalignment between adjacent piezoelectric ceramic sheets; in addition, there is no positioning device between the stator and the rotor of the motor, which affects the accuracy of the contact position between the stator and the rotor, thereby affecting the motor. Stability of torque and speed; This type of rotating ultrasonic motor has problems such as complex structure, difficult manufacturing and installation, high cost, and poor stability of motor torque and speed.

Contents of the invention

In order to overcome the deficiencies in the prior art, the purpose of this utility model is to provide a new single electric signal driven rotary ultrasonic motor.

The rotary ultrasonic motor driven by a single electric signal is characterized in that it includes a mandrel and a rear cover plate sequentially sleeved on the mandrel, a piezoelectric ceramic sheet, an electrode sheet, an elliptical vibration mode converter, a friction disc, a bearing, a spring and a nut ; The mandrel, the back cover, the piezoelectric ceramic sheet, the electrode sheet, and the elliptical vibration mode converter constitute the stator part of the ultrasonic motor, and the mandrel and the elliptical vibration mode converter are threaded to connect the back cover , piezoelectric ceramic sheet, electrode sheet and elliptical vibration mode converter are compressed and fixed to form the energy conversion part of the ultrasonic motor, which converts the ultrasonic electric energy output by the ultrasonic power supply into the ultrasonic vibration energy of the stator part.

The elliptical vibration mode converter is an integrated structure, including a cylindrical part at the lower end and a driving tooth part at the upper end, and the driving tooth parts are uniformly arranged on the upper end of the cylindrical part in the circumferential direction, and each driving tooth is The radial direction is an oblique wedge structure. The projection of the original overall structure of the oblique wedge along the radial direction is a rectangle. One side is cut off along the axial direction of the ultrasonic motor to form an oblique wedge structure, that is, the two sides of the oblique wedge are formed. , the radial projection of the uncut side is parallel to the axis of the ultrasonic motor, the radial projection of the other cut side is at an angle of 3-40 degrees to the axis of the ultrasonic motor, and the number of driving teeth is 3 -12 pcs.

The purpose of making the drive tooth form a wedge-shaped structure is to change the vibration mode of the elliptical vibration mode converter, so that the modal frequency of the longitudinal vibration and the mode frequency of the bending vibration are close to or equal. Due to the existence of the wedge-shaped structure, the ultrasonic motor After the longitudinal ultrasonic vibration generated by the energy conversion part is transmitted to the end of the wedge-shaped drive tooth, it is decomposed into a part of the longitudinal vibration component and a part of the bending vibration component at the end of the wedge-shaped drive tooth, and the two vibration components have a certain phase difference. The wedge-shaped structure drives the end of the tooth to compound to form an elliptical vibration track, which is converted into the longitudinal-bending composite ultrasonic elliptical vibration of the end of the elliptical vibration mode converter driving the tooth along the tangential direction of the ultrasonic motor circle.

The friction disc and the bearing constitute the rotor part of the ultrasonic motor; the spring and the nut constitute the positive pressure pretightening force adjustment mechanism of the rotor part and the stator part of the ultrasonic motor.

Furthermore, the end of the driving tooth of the elliptical vibration mode converter is bonded with A friction material.

Furthermore, the end surface of the friction disc that is in contact with the driving teeth is bonded with B friction material.

Furthermore, the rear cover plate and the mandrel can be made into a separate structure or an integrated structure.

The stator of the utility model adopts a sandwich transducer structure, and through a specially designed elliptical vibration mode converter, a group of longitudinal vibration modes of piezoelectric ceramics are used to realize the elliptical track movement of the particle end surface of the stator driving teeth, and drive the rotor to rotate, with The utility model has the advantages of simple structure, large power capacity, easy manufacture and low assembly difficulty; in addition, the utility model only needs a set of control circuit and its drive power supply, the control drive system is simple, easy to manufacture, less difficult to control, and high in reliability; at the same time, the utility model The new type has the advantages of small size, light weight, easy miniaturization, integration, low cost, high torque at low speed, low noise, fast response, high positioning accuracy, no electromagnetic interference and strong environmental adaptability, etc., and has broad application prospects.

Description of drawings

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

Fig. 2 is a three-dimensional exploded view of parts of the utility model.

Fig. 3 is a schematic diagram of the three-dimensional structure of the elliptical vibration mode converter of the present invention.

Fig. 4 is a schematic diagram of an application example of the utility model.

Explanation of symbols in the figure: 1. Mandrel, 2. Back cover, 3. Piezoelectric ceramic sheet, 4. Electrode sheet, 5. Elliptical vibration mode converter, 6. A friction material, 7. B friction material, 8 .Friction disc, 9. Bearing, 10. Spring, 11. Nut, 12. Ultrasonic power supply

Detailed ways

As shown in Figures 1, 2, 3, and 4, the single electric signal-driven rotary ultrasonic motor of the present invention includes a mandrel 1 and a back cover 2, a piezoelectric ceramic sheet 3, and an electrode sheet that are sequentially sleeved on the mandrel 1 4. Elliptical vibration mode converter 5, friction disc 8, bearing 9, spring 10 and nut 11; said mandrel 1, rear cover plate 2, piezoelectric ceramic sheet 3, electrode sheet 4, elliptical vibration mode converter 5 constitutes the stator part of the ultrasonic motor, which is connected through the external thread on the mandrel 1 and the internal thread of the elliptical vibration mode converter 5, and the rear cover plate 2, the piezoelectric ceramic sheet 3, the electrode sheet 4 and the elliptical vibration mode converter 5 are connected. The mode converter 5 is compressed and fixed, and constitutes the energy conversion part of the ultrasonic motor, which can convert the ultrasonic electric energy output by the ultrasonic power supply 12 into the ultrasonic vibration energy of the ultrasonic motor. The manufacturing components of the rear cover 2 and the mandrel 1 asana structure.

The elliptical vibration mode converter 5 is an integrated structure, including a cylindrical part at the lower end and a driving tooth part at the upper end, and the driving tooth part is evenly arranged on the upper end of the cylindrical part in the circumferential direction, and each driving tooth is along the radial direction. Oblique wedge-shaped structure, the projection of the original oblique wedge-shaped overall structure along the radial direction is a rectangle, and a part of one side is cut off along the axial direction of the ultrasonic motor to form an oblique wedge-shaped structure, that is, the two sides of the oblique wedge shape are not cut The radial projection of one side is parallel to the axis of the ultrasonic motor, and the radial projection of the other cut side forms an angle of 24 degrees with the axis of the ultrasonic motor. The width of the small end of the drive tooth is 1.5mm, and the height is 7.5mm. The number of said driving teeth is 6, and the end of the driving teeth is bonded with A friction material 6 .

The friction disc 8 and the bearing 9 constitute the rotor part of the ultrasonic motor. The friction disc 8 and the bearing 9 are connected together by a transition fit and then sleeved on the mandrel 1. The end surface of the friction disc 8 in contact with the driving teeth is bonded with B friction material 7 The spring 10 and the nut 11 constitute the positive pressure preload adjustment mechanism of the ultrasonic motor rotor part and the stator part, and the compression amount of the spring 10 can be changed by adjusting the position of the nut 11 on the mandrel 1, thereby adjusting the motor rotor to the motor stator The pre-pressure is set to 6N.

The external diameter of the rotary ultrasonic motor driven by a single electric signal is 10mm, the length is 55mm, the piezoelectric ceramic used is PZT-8, the size is Ф10×Ф5×2mm , the natural frequency is 99.6KHz, the impedance is 76 ohms, the dynamic resistance is 21 ohms, the ultrasonic power supply 12 The output voltage range is 0-400V, the current range is 0-4A, the output frequency is 99.6±0.01KHz, and the ultrasonic power supply 12 has an automatic frequency tracking function within the specified frequency range.

As shown in FIG. 4 , during operation, after the electrode sheet 4 of the rotating ultrasonic motor driven by a single electric signal is connected to the electrical signal output by the ultrasonic power supply 12, due to the inverse piezoelectric effect of the piezoelectric ceramic sheet 3, the piezoelectric ceramic sheet 3 will Generate longitudinal ultrasonic vibration, that is, convert the electric energy output by the ultrasonic power supply 12 into ultrasonic vibration energy, and drive the entire stator to perform longitudinal ultrasonic vibration. When the ultrasonic vibration energy is transmitted from the stator to the end of the elliptical vibration mode converter 5, it is converted into a Longitudinal vibration with a certain phase difference and bending vibration compound longitudinal-bending composite ultrasonic elliptical vibration, which is converted into elliptical vibration mode converter 5 drives the longitudinal-bending composite ultrasonic elliptical vibration of the end of the drive tooth along the tangential direction of the ultrasonic motor circumference, drives the end of the tooth and friction The discs 8 are in contact with each other, and then drive the rotor to rotate. After the ultrasonic motor runs continuously for 30 minutes, the output voltage of the ultrasonic power supply 12 is 100V, the current is 0.26A, and the rotation speed of the rotor is 486r/min, and the operation is in good condition.

Claims (5)

1. single-electrical signal drives rotary ultrasonic motor, it is characterized in that: comprise axle and be set in successively back shroud, piezoelectric ceramic piece, electrode slice, elliptical vibration MODAL TRANSFORMATION OF A device, frictional disk, bearing, spring and the nut in axle, described axle, back shroud, piezoelectric ceramic piece, electrode slice, elliptical vibration MODAL TRANSFORMATION OF A device form the stationary part of described ultrasound electric machine, and axle and elliptical vibration MODAL TRANSFORMATION OF A device are fixed back shroud, piezoelectric ceramic piece, electrode slice and elliptical vibration MODAL TRANSFORMATION OF A device after by thread connection, described frictional disk and bearing form the rotor portion of ultrasound electric machine, described spring and nut form the malleation prefastening force adjustment mechanism of ultrasound electric machine rotor portion and stationary part, described elliptical vibration MODAL TRANSFORMATION OF A device is integrated, comprise the barrel portion of lower end and the driving gear part of upper end, described driving gear part is in the uniform upper end that is arranged on barrel portion of circumferencial direction, each driving gear is radially inclined wedge-shaped structure, the former overall structure of this inclined wedge-shaped radially be projected as rectangle, after being cut a part, ultrasound electric machine axis direction one side forms inclined wedge-shaped structure, form in two sides of inclined wedge-shaped, the projection radially of a cut side is not parallel to ultrasound electric machine axis, the another side being cut projection radially becomes 3-40 degree angle with ultrasound electric machine axis.

2. single-electrical signal according to claim 1 drives rotary ultrasonic motor, it is characterized in that: on described elliptical vibration MODAL TRANSFORMATION OF A device, the quantity of driving gear is 3-12.

3. single-electrical signal according to claim 1 drives rotary ultrasonic motor, it is characterized in that: described back shroud and described axle are made into split-type structural or integral structure.

4. according to the single-electrical signal described in claim 1 or 2 or 3, drive rotary ultrasonic motor, it is characterized in that: described elliptical vibration MODAL TRANSFORMATION OF A device driving gear end is bonded with A friction material.

5. according to the single-electrical signal described in claim 1 or 2 or 3, drive rotary ultrasonic motor, it is characterized in that: the end face contacting with driving gear on described frictional disk is bonded with B friction material.

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