Linear ultrasonic motor with longitudinal vibration composite configuration

Abstract

The invention discloses a linear ultrasonic motor with a longitudinal vibration composite configuration, and relates to the technical field of ultrasonic motors. The sandwich type piezoelectric vibrator comprises two sandwich type piezoelectric vibrators, wherein the two sandwich type piezoelectric vibrators are arranged in parallel; each sandwich type piezoelectric vibrator comprises a front elastic body, a clamping block, a rear elastic body and two pairs of ceramic chips respectively clamped between the front elastic body and the clamping block and between the clamping block and the rear elastic body, an electrode slice is clamped between each pair of ceramic chips, and an inverted V-shaped driving foot is connected between the front elastic bodies of the two sandwich type piezoelectric vibrators. According to the linear ultrasonic motor, the two sandwich type piezoelectric vibrators are arranged side by side in parallel, so that the overall structure is more compact, the overall volume utilization rate of the linear ultrasonic motor is effectively improved, two different excitation modes are adopted for excitation, and the actual application requirements of different precision devices can be met by selecting the proper excitation mode; and the use flexibility and the adaptability to the use environment of the linear ultrasonic motor are effectively improved.

Description

Technical Field

[0001] The invention belongs to the technical field of ultrasonic motors, and in particular relates to a linear ultrasonic motor with a longitudinal vibration composite configuration. Background Art

[0002] Ultrasonic motor is a new type of actuator that uses the inverse piezoelectric effect and friction effect of piezoelectric materials to drive the rotor. Ultrasonic motor has the advantages of flexible and simple structure, high positioning accuracy, good dynamic response, and non-electric self-locking.

[0003] For example, China uses the new CN216290731U, which discloses a V-shaped sandwich linear motor stator. It uses two sandwich piezoelectric vibrators to form a V-shaped structure, increases the number of piezoelectric ceramic sheets, and separates the symmetric mode and the asymmetric mode by adjusting the polarization direction of the piezoelectric ceramics, thereby achieving decoupling of the tangential displacement and the normal displacement, thereby independently controlling the tangential displacement and the normal displacement to achieve low-speed and high torque.

[0004] However, in the existing V-shaped sandwich ultrasonic motor, the two legs of the motor stator are perpendicular to each other, and in practical applications, there are often high requirements for the volume of the linear ultrasonic motor. From the perspective of space utilization, the space between the two legs of the stator of the V-shaped sandwich ultrasonic motor is completely unutilized, resulting in poor overall volume utilization. Summary of the invention

[0005] The object of the present invention is to provide a linear ultrasonic motor with a longitudinal vibration composite configuration, by arranging two sandwich-type piezoelectric vibrators side by side in parallel, so that the overall structure is more compact, thereby solving the problem of poor overall volume utilization of existing linear ultrasonic motors.

[0006] In order to solve the above technical problems, the present invention is achieved through the following technical solutions:

[0007] The present invention is a linear ultrasonic motor with a longitudinal vibration composite configuration, comprising a base and a slide and a stator located on the upper surface of the base, wherein the stator comprises two sandwich piezoelectric vibrators, and the two sandwich piezoelectric vibrators are arranged in parallel; each of the sandwich piezoelectric vibrators comprises a front elastic body, a clamping block and a rear elastic body, and two pairs of ceramic sheets clamped between the front elastic body and the clamping block and between the clamping block and the rear elastic body respectively, an electrode sheet is clamped between each pair of the ceramic sheets, and the polarization directions of the piezoelectric ceramics on both sides of the same electrode sheet are opposite; wherein an inverted V-shaped driving foot is connected between the front elastic bodies of the two sandwich piezoelectric vibrators.

[0008] As a preferred technical solution of the present invention, the clamping block and the base are connected by screws, and the screw sleeve is provided with an elastic member; the elastic member pushes the clamping block toward the slide, and is used to adjust the preload force between the driving foot and the friction strip of the slide through the axial movement of the screw.

[0009] As a preferred technical solution of the present invention, the contact portion between the driving foot and the friction strip is coated with an aluminum oxide friction plate.

[0010] As a preferred technical solution of the present invention, the front elastic body, the clamping block and the rear elastic body are all grounded through wires.

[0011] As a preferred technical solution of the present invention, the two front elastic bodies and the driving foot are an integrated structure.

[0012] A driving method for a linear ultrasonic motor with a longitudinal vibration composite configuration includes: single-phase excitation, applying an excitation signal to a ceramic sheet of one of the sandwich piezoelectric vibrators, driving a slide table to move to one side through a driving foot, and when an excitation signal is applied to a ceramic sheet of another sandwich piezoelectric vibrator, the slide table moves in the opposite direction.

[0013] As a preferred technical solution of the present invention, it also includes: two-phase excitation, by applying an A-phase excitation signal to the ceramic plate of one of the sandwich piezoelectric vibrators, and applying a B-phase excitation signal to the ceramic plate of the other sandwich piezoelectric vibrator, and the frequencies of the A-phase excitation signal and the B-phase excitation signal differ by π / 2, so that the top of the driving foot drives the slide in an elliptical trajectory; wherein, when the frequencies of the A-phase excitation signal and the B-phase excitation signal differ by -π / 2, the slide is driven to move in the opposite direction.

[0014] The present invention has the following beneficial effects:

[0015] The present invention arranges two sandwich-type piezoelectric vibrators in parallel side by side, so that the overall structure is more compact, which is beneficial to improving the overall volume utilization. At the same time, an inverted V-shaped driving foot is connected between the front elastic bodies of the two sandwich-type piezoelectric vibrators. By performing single-phase or two-phase excitation on the sandwich-type piezoelectric vibrators, the driving foot generates an oblique arc motion and an elliptical motion trajectory, thereby driving the slide, and the forward and reverse directions of the slide of the motor can obtain consistent output performance, so that the overall performance of the linear ultrasonic motor is improved, and two different excitation methods are used for excitation, and a suitable excitation method can be selected to meet the actual application requirements of different precision devices, effectively improving the flexibility of use of the linear ultrasonic motor and its adaptability to the use environment.

[0016] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0018] Figure 1 It is a structural schematic diagram of a linear ultrasonic motor of a longitudinal vibration composite configuration according to the present invention;

[0019] Figure 2 is a schematic diagram of the structure of the stator;

[0020] Figure 3 for Figure 2 A top view of

[0021] Figure 4 The schematic diagram of the motion trajectory of the driving foot of the stator when the stator is excited in two phases;

[0022] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0023] 1-base, 2-slide, 3-sandwich piezoelectric vibrator, 4-ceramic sheet, 101-screw, 102-elastic member, 301-front elastic body, 302-clamping block, 303-rear elastic body, 304-driving foot, 401-electrode sheet. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] In the description of the present invention, it should be understood that the terms "opening", "upper", "lower", "thickness", "top", "middle", "length", "inside", "all around" and the like indicating orientation or positional relationship are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the components or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0026] Embodiment 1

[0027] See also Figure 1As shown, the present invention is a linear ultrasonic motor of a longitudinal vibration composite configuration, comprising a base 1 and a slide 2 and a stator located on the upper surface of the base 1, wherein the stator comprises two sandwich-type piezoelectric vibrators 3, and the two sandwich-type piezoelectric vibrators 3 are arranged in parallel and side by side, so that the overall structure is more compact, and other components can be flexibly installed on the base 1, which is beneficial to improving the overall volume utilization.

[0028] like Figure 2 As shown, each sandwich piezoelectric vibrator 3 includes a front elastic body 301, a clamping block 302 and a rear elastic body 303, and two pairs of ceramic sheets 4 clamped between the front elastic body 301 and the clamping block 302 and between the clamping block 302 and the rear elastic body 303 respectively.

[0029] Each pair of ceramic sheets 4 is sandwiched with an electrode sheet 401, and the polarization directions of the piezoelectric ceramics 4 on both sides of the same electrode sheet 401 are opposite, and the polarization direction of a single ceramic sheet 4 is along the thickness direction, so that the ceramic sheet does not need polarization partitioning, thereby effectively improving the polarization convenience of the ceramic sheet. The ceramic sheet 4 is made of PZT material, and the electrode sheet 401 is made of brass. The electrode sheet 401 is used to connect the wire to apply an excitation signal to the ceramic sheet 4, and the front elastic body 301, the clamping block 302 and the rear elastic body 303 are all grounded through wires.

[0030] Among them, an inverted V-shaped driving foot 304 is connected between the front elastic bodies 301 of the two sandwich-type piezoelectric vibrators 3, and the two front elastic bodies 301 and the driving foot 304 are an integrated structure formed by mechanical processing.

[0031] The ends of the two front elastic bodies 301 are provided with threaded holes, and the clamping block 302, the ceramic sheet 4, the electrode sheet 401 and the rear elastic body 303 are all provided with through holes. The whole is locked by locking screws so that the whole is clamped and fixed to each other.

[0032] At the same time, the clamping block 302 is connected to the base 1 by means of screws 101. For example, a connecting block is provided on the upper surface of the base 1, the connecting block is provided with a threaded hole matching with the screw 101, and the clamping block 302 is provided with a connecting hole, so that the screw 101 passes through the connecting hole of the holding block 302 and is connected with the connecting block to realize the installation of the stator.

[0033] In addition, the screw 101 is sleeved with an elastic member 102, which can be a compression spring. The elastic member 102 is located on the side of the clamping block 302 away from the slide 2. The clamping block 302 is pushed toward the slide 2 by the elastic member 102. Through the axial movement of the screw 101, the extrusion force applied by the elastic member 102 to the clamping block 302 is adjusted, thereby realizing the adjustment of the preload force between the driving foot 304 and the friction strip of the slide 2.

[0034] In addition, the contact portion between the driving foot 304 and the friction strip is covered with an aluminum oxide friction sheet, and the side of the friction strip may also be covered with an aluminum oxide friction strip to reduce the wear between the driving foot 304 and the slide table 2 .

[0035] Embodiment 2

[0036] like Figure 3 As shown, based on the first embodiment, a driving method of a linear ultrasonic motor with a longitudinal vibration composite configuration includes a single-phase excitation mode:

[0037] By applying an excitation signal to the ceramic sheet 4 of one of the sandwich piezoelectric vibrators 3, the slide 2 is driven to move to one side through the driving foot 304. As shown in the figure, the excitation signal is applied to the two electrode sheets 401 of the sandwich piezoelectric vibrator 3 on the left, and the ceramic sheet 4 is deformed so that the sandwich piezoelectric vibrator 3 on the left is stretched as a whole, while the length of the sandwich piezoelectric vibrator 3 on the right remains unchanged. At this time, the driving foot 304 is pushed to the right and deformed, thereby driving the slide 2 to move to the right.

[0038] Furthermore, when the slide 2 needs to move to the left, an excitation signal is applied to the ceramic sheet 4 of the sandwich piezoelectric vibrator 3 on the right side, and the sandwich piezoelectric vibrator 3 on the right side pushes the driving foot 304 to the left side, thereby achieving reverse movement of the slide 2.

[0039] Embodiment 3

[0040] like Figure 4 As shown, based on the second embodiment, a method for exciting a linear ultrasonic motor of a longitudinal vibration composite configuration further includes a two-phase excitation mode:

[0041] By applying an A-phase excitation signal to the ceramic sheet 4 of one sandwich piezoelectric vibrator 3 and applying a B-phase excitation signal to the ceramic sheet 4 of the other sandwich piezoelectric vibrator 3, both the A-phase excitation signal and the B-phase excitation signal are sinusoidal signals, and the frequencies of the A-phase excitation signal and the B-phase excitation signal differ by π / 2, the top of the driving foot 304 drives the slide 2 to move toward one side in an elliptical trajectory. When the frequencies of the A-phase excitation signal and the B-phase excitation signal differ by -π / 2, the slide 2 is driven to move in the opposite direction toward the other side.

[0042] At the same time, by flexibly adopting the single-phase excitation or two-phase excitation mode, the driving foot 301 can produce oblique circular arc motion and elliptical motion trajectory, realize the driving of the slide 2, and the motor slide 2 can obtain consistent output performance in both forward and reverse directions, so that the overall performance of the linear ultrasonic motor is improved.

[0043] Furthermore, by adopting two different excitation modes for excitation, a suitable excitation mode can be selected to meet the actual application requirements of different precision devices, thereby effectively improving the use flexibility and adaptability of the linear ultrasonic motor to the use environment.

[0044] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0045] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A linear ultrasonic motor of longitudinal vibration composite configuration, comprising a base (1), a slide (2) and a stator located on the upper surface of the base (1), characterized in that: The stator comprises two sandwich-type piezoelectric vibrators (3), and the two sandwich-type piezoelectric vibrators (3) are arranged in parallel; each of the sandwich-type piezoelectric vibrators (3) comprises a front elastic body (301), a clamping block (302), a rear elastic body (303), and two pairs of ceramic sheets (4) respectively clamped between the front elastic body (301) and the clamping block (302) and between the clamping block (302) and the rear elastic body (303), An electrode sheet (401) is sandwiched between each pair of ceramic sheets (4), and the piezoelectric ceramics (4) on both sides of the same electrode sheet (401) have opposite polarization directions; Wherein, an inverted V-shaped driving foot (304) is connected between the front elastic bodies (301) of the two sandwich-type piezoelectric vibrators (3).

2. A linear ultrasonic motor with a longitudinal vibration composite structure according to claim 1, characterized in that: The clamping block (302) and the base (1) are connected via a screw (101), and the screw (101) is sleeved with an elastic member (102); The elastic member (102) pushes the clamping block (302) toward the slide table (2) and is used to adjust the preload force between the driving foot (304) and the friction strip of the slide table (2) through the axial movement of the screw (101).

3. A linear ultrasonic motor with a longitudinal vibration composite structure according to claim 1 or 2, characterized in that: The contact portion between the driving foot (304) and the friction strip is coated with an aluminum oxide friction plate.

4. The linear ultrasonic motor of longitudinal vibration composite configuration according to claim 1, characterized in that: The front elastic body (301), the clamping block (302) and the rear elastic body (303) are all grounded via wires.

5. The linear ultrasonic motor of longitudinal vibration composite configuration according to claim 1, characterized in that: The two front elastic bodies (301) and the driving foot (304) are an integrated structure.

6. A driving method for a linear ultrasonic motor of a longitudinal vibration composite configuration according to any one of claims 1 to 5, characterized in that: include: Single Phase Excitation, by applying an excitation signal to the ceramic sheet (4) of one of the sandwich-type piezoelectric vibrators (3), the slide table (2) is driven to move toward one side through the driving foot (304), and when the excitation signal is applied to the ceramic sheet (4) of the other sandwich-type piezoelectric vibrator (3), the slide table (2) is moved in the opposite direction.

7. The method for exciting a linear ultrasonic motor of a longitudinal vibration composite configuration according to claim 6, characterized in that: Also includes: Dual-phase excitation, by applying an A-phase excitation signal to the ceramic sheet (4) of one of the sandwich-type piezoelectric vibrators (3), and applying a B-phase excitation signal to the ceramic sheet (4) of the other sandwich-type piezoelectric vibrator (3), and the frequencies of the A-phase excitation signal and the B-phase excitation signal differ by π / 2, so that the top of the driving foot (304) drives the slide table (2) to move along an elliptical trajectory; When the frequency difference between the A-phase excitation signal and the B-phase excitation signal is -π / 2, the slide table (2) is driven to move in the reverse direction.

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