An in-plane traveling wave linear ultrasonic motor and a platform feeding device

Abstract

The invention relates to an in-plane traveling wave linear ultrasonic motor and a platform feeding device. The ultrasonic motor comprises a stator assembly and a mover. The stator assembly is an overall cylindrical structure, comprising an annular cylindrical stator, a plurality of racks are evenly arranged on the circumferential surface of the annular cylindrical stator, and two symmetrical thin-sheet annular elastic substrates are respectively arranged on the two end surfaces of the annular cylindrical stator; the ultrasonic motor also comprises two groups of piezoelectric ceramic sheet groups symmetrically arranged around the annular cylindrical stator, one side of each group of piezoelectric ceramic sheets is connected to the thin-sheet annular elastic substrate, and a conductive film is arranged on the other side of each group of piezoelectric ceramic sheets, and the thin-sheet annular elastic substrate is located between the annular cylindrical stator and the piezoelectric ceramic sheet group; the mover is arranged in an elongated strip shape and is suspended on the circumferential surface of the annular cylindrical stator; the invention ensures that the frequency consistency is easy to adjust when the stator size changes, has a simple structure, is easy to miniaturize, and can maintain high precision at the same time.

Description

Technical Field

[0001] The invention relates to an in-plane traveling wave linear ultrasonic motor and a platform feeding device, belonging to the technical field of ultrasonic motors. Background Art

[0002] As a classification of ultrasonic motors, linear ultrasonic motors also use the inverse piezoelectric effect of piezoelectric elements and the ultrasonic vibration of elastic bodies. Through the friction between the stator and the mover, the micro-vibration of the elastic body is converted into the macroscopic linear motion of the mover, directly pushing the load. It has many advantages such as directly generating linear motion and traction, high positioning and speed control accuracy, compact structure and flexible design, and can be lightweight and miniaturized. So far, many types of linear ultrasonic motors have appeared, which can be classified into standing wave type and traveling wave type according to the different wave forms. Among them, the standing wave type can be divided into single-leg type and multi-leg type according to the number of driving feet on the stator; the traveling wave type can be divided into straight beam type and ring beam type. According to whether the vibration displacement direction used by the linear ultrasonic motor is perpendicular to the stator surface or in the plane of the stator, the linear ultrasonic motor is divided into two types: out-of-plane vibration and in-plane vibration.

[0003] In 1983, based on the research of traveling wave rotary ultrasonic motor, Japanese scholar Sashida proposed two types of traveling wave linear ultrasonic motors, one is ring beam type and the other is straight beam type; in 1998, German scholars Hermann and Schinkothe ​​developed a ring beam traveling wave linear ultrasonic motor, which evolved from the rotary ultrasonic motor. In order to prevent the reflection of waves, the guide rail is made into a closed ring beam, and the piezoelectric ceramics bonded to the inner side of the ring beam are used to excite the traveling wave on the surface of the ring beam. When the mover is pressed on the straight section of the ring beam, the mover will produce linear motion; in 1998, many Japanese electronics companies launched a thin linear ultrasonic motor, which uses triangular piezoelectric ceramic sheets as piezoelectric vibrators and is driven on one side. Since then, German PI has also developed similar linear ultrasonic motors. The traveling wave linear ultrasonic motor proposed by Zhong Kansheng et al. in Chinese Patent 201110039747.4 uses the out-of-plane mode of the annular elastic matrix to form traveling waves, and uses the outer edge of the stator to drive the axial movement of the guide rail.

[0004] In recent years, many new types of linear ultrasonic motors have emerged. Regardless of whether it is a standing wave linear ultrasonic motor or a traveling wave linear ultrasonic motor, there are problems in that the frequency consistency adjustment is greatly affected by the change of the stator size (when the stator size becomes smaller, the frequency consistency adjustment is difficult) and the fixation is difficult. Therefore, the miniaturization of the motor is subject to certain restrictions. At the same time, due to the poor frequency consistency, the control of the motor will also be affected accordingly. Therefore, there is an urgent need for a new type of ultrasonic motor that can solve the problems of frequency consistency adjustment difficulty and fixation difficulty. Summary of the invention

[0005] The present invention provides an in-plane traveling wave linear ultrasonic motor and a platform feeding device, which ensure that the frequency consistency is easy to adjust when the stator size changes, have a simple structure, are easy to miniaturize, and can maintain high precision.

[0006] The technical solution adopted by the present invention to solve the technical problem is:

[0007] An in-plane traveling wave linear ultrasonic motor comprises a stator assembly and a mover. The stator assembly is a cylindrical structure as a whole, comprising a circular cylindrical stator, a plurality of racks are evenly arranged on the circumferential surface of the circular cylindrical stator, and two symmetrical thin circular ring-shaped elastic substrates are respectively arranged on the two end surfaces of the circular cylindrical stator;

[0008] It also includes two groups of piezoelectric ceramic sheets symmetrically arranged around the annular cylindrical stator, one side of each group of piezoelectric ceramic sheets is connected to a thin annular elastic matrix, a conductive film is arranged on the other side of each group of piezoelectric ceramic sheets, and the thin annular elastic matrix is ​​located between the annular cylindrical stator and the piezoelectric ceramic sheet group;

[0009] Partition polarization on the surface of piezoelectric ceramics;

[0010] The mover is arranged in a long strip shape, suspended on the circumferential surface of the annular cylindrical stator, and the part where the mover contacts the annular cylindrical stator is in a T shape, and the transverse part of the T shape contacts the circumferential surface of the annular cylindrical stator;

[0011] As a further preferred embodiment of the present invention, a counterweight structure for positioning the annular cylindrical stator is installed in the thin annular elastic base structure;

[0012] A flexible web is installed in the space between the counterweight structure and the thin circular ring-shaped elastic base structure, and the counterweight structure, the flexible web and the thin circular ring-shaped elastic base are located in the same plane;

[0013] As a further preferred embodiment of the present invention, a plurality of racks are evenly arranged on the circumferential surface of the annular cylindrical stator, each rack is arranged in a concave structure, and its opening portion faces the center of the annular cylindrical stator;

[0014] Affix friction material to the tooth surface of one of the racks;

[0015] As a further preferred embodiment of the present invention, the piezoelectric ceramic sheet group includes a plurality of piezoelectric ceramic sheets connected in sequence, and each piezoelectric ceramic sheet group is in a circular ring shape matching the circular ring-shaped elastic matrix structure of the thin sheet;

[0016] One side of the piezoelectric ceramic sheet is adhered to a thin circular elastic substrate adjacent to it, and a plurality of piezoelectric ceramic sheets are divided into a plurality of polarization partitions;

[0017] A platform feeding device based on an in-plane traveling wave linear ultrasonic motor comprises a machine cover, a support member, a base, a slide rail assembly and a working platform, wherein the support member is arranged in a U-shaped structure, the stator assembly is fixed in the U-shaped structure formed by the support member, and the closed end of the support member is mounted on the machine cover;

[0018] A slide bar is installed on the outward side of the vertical part of the support, and the slide bar is parallel to the radial direction of the inner cylindrical stator of the stator assembly. The base is also a U-shaped structure, which can be movably sleeved on the support, and slide grooves are respectively provided on the inner side of the vertical part of the base, and the slide grooves match the slide bar;

[0019] A slide rail assembly is installed on the transverse part of the base, and the bottom of the working platform is movably connected to the transverse part of the base through the slide rail assembly;

[0020] The mover is installed on the side of the working platform opposite to the stator assembly, and the part of the mover that contacts the annular cylindrical stator is in a T shape, and the transverse part of the T shape contacts the circumferential surface of the annular cylindrical stator;

[0021] As a further preferred embodiment of the present invention, a pre-pressure adjustment gasket is provided at the connection between the closed end of the support member and the machine cover.

[0022] Through the above technical solution, compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. The present invention solves the problem of difficulty in adjusting the frequency consistency when the stator size of the existing linear ultrasonic motor changes. Compared with the existing traveling wave linear ultrasonic motor and some other standing wave linear ultrasonic motors, the present invention is easier to fix, easier to miniaturize, and has higher control accuracy.

[0024] 2. The present invention can not only be used for precision platform feeding, but also has broad application prospects in biomedicine, robotics, etc.;

[0025] 3. The present invention can amplify the radial amplitude and circumferential amplitude of the annular cylindrical stator, so that the ellipse excited for driving is better, thereby improving the output capacity of the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0027] Figure 1 It is a schematic diagram of the structure of the in-plane traveling wave linear ultrasonic motor of the present invention;

[0028] Figure 2 It is an exploded schematic diagram of a stator assembly of a preferred embodiment of an in-plane traveling wave linear ultrasonic motor of the present invention;

[0029] Figure 33a is a schematic diagram of the structure of a circular cylindrical stator of a preferred embodiment of the in-plane traveling wave linear ultrasonic motor of the present invention, wherein 3a is a three-dimensional schematic diagram and 3b is a cross-sectional schematic diagram;

[0030] Figure 4 4a and 4b are schematic diagrams of two orthogonal modal vibration shapes at the same frequency in Example 2;

[0031] Figure 5 5a is a schematic diagram of the partitioning and polarization of the piezoelectric ceramic sheets of the preferred embodiment of the in-plane traveling wave linear ultrasonic motor of the present invention, wherein 5a is the partitioning polarization of one group of piezoelectric ceramic sheets in embodiment 2, and 5b is the partitioning polarization of another group of piezoelectric ceramic sheets;

[0032] Figure 6 It is a structural schematic diagram of a platform feeding device based on an in-plane traveling wave linear ultrasonic motor of the present invention;

[0033] Figure 7 It is the spur-tooth stator structure selected in the comparative test of the preferred embodiment of the present invention;

[0034] Figure 8 This is a schematic diagram comparing the radial and circumferential amplitudes of a spur-tooth stator under the conditions of 100V voltage and 3 / 1000 damping ratio;

[0035] Fig. 9 It is a schematic diagram of radial and circumferential amplitude comparison under the conditions of 100V voltage and 0.3% damping ratio of the preferred embodiment 1 of the present invention;

[0036] Fig.10 It is a comparison diagram of the ellipses on the radial and circumferential planes formed on the stator teeth of the stator structure of the present application and the spur-tooth stator structure under their respective optimal conditions.

[0037] In the figure: 1 is the mover, 2 is the stator assembly, 3 is the support, 4 is the pre-pressure adjustment gasket, 5 is the machine cover, 6 is the base, 7 is the slide rail assembly, 8 is the working platform, 2-1a is the conductive film, 2-1b is the conductive film, 2-2a is the piezoelectric ceramic sheet, 2-2b is the piezoelectric ceramic sheet, 2-3 is the friction material, 2-4 is the annular cylindrical stator, 2-4-1 is the counterweight structure, 2-4-2 is the flexible web, 2-4-3 is the thin-sheet annular elastic matrix, and 2-4-4 is the rack. DETAILED DESCRIPTION

[0038] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, which only illustrate the basic structure of the present invention in a schematic manner, and therefore only show the components related to the present invention.

[0039] In the existing linear ultrasonic motors, whether it is a standing wave linear ultrasonic motor or a traveling wave linear ultrasonic motor, since its structure is not centrally symmetrical like a standard circular ring, the adjustment of the modal frequency consistency is greatly affected by the change of the stator size. That is to say, when the stator size changes, the adjustment of the frequency consistency takes a lot of time and effort, and the clamping and fixing is also difficult, which seriously affects the mechanical properties of the motor and the miniaturization of the motor. Therefore, based on the current situation, the present application proposes a new type of in-plane traveling wave linear ultrasonic motor. Figure 1 As shown, from the overall point of view, the stator assembly 2 of the present application is a highly symmetrical circular columnar structure, on the circumferential surface of which the mover 1 is suspended. The stator assembly 2 is set as a highly symmetrical structure, which can solve the problem of difficulty in adjusting the frequency consistency when the stator size changes to a certain extent.

[0040] Embodiment 1:

[0041] Make a selection of the solution proposed in this application. Figure 2 As shown, it is a stator assembly 2 selected in the preferred embodiment, which is a cylindrical structure as a whole, including a circular cylindrical stator 2-4, a plurality of racks 2-4-4 are evenly arranged on the circumferential surface of the circular cylindrical stator 2-4, and two symmetrical thin circular ring-shaped elastic substrates 2-4-3 are respectively arranged on the two end surfaces of the circular cylindrical stator 2-4;

[0042] Two groups of piezoelectric ceramic sheets 2-2a and 2-2b are symmetrically arranged with the annular cylindrical stator 2-4 as the center, one side of each group of piezoelectric ceramic sheets 2-2a and 2-2b is connected to a thin annular elastic matrix 2-4-3, and a conductive film 2-1a and 2-1b is arranged on the other side of each group of piezoelectric ceramic sheets 2-2a and 2-2b, and the thin annular elastic matrix 2-4-3 is located between the annular cylindrical stator 2-4 and the piezoelectric ceramic sheets 2-2a and 2-2b;

[0043] Depend on Figure 3 It can be clearly seen in Figure 3a that a number of racks 2-4-4 are evenly arranged on the circumferential surface of the annular cylindrical stator 2-4, and each rack 2-4-4 is arranged in a concave structure, and its opening portion faces the center of the annular cylindrical stator 2-4; the setting of this concave structure can greatly amplify the radial amplitude and lateral amplitude of the annular cylindrical stator 2-4, while still ensuring that the amplitude of the rack 2-4-4 in the axial direction of the annular cylindrical stator 2-4 is small, so the ellipse stimulated for driving can improve the output capacity of the motor.

[0044] The structure in the preferred embodiment 1 of the present application is combined with Figure 7 For comparison, Figure 7The selected stator diameter is 30 mm and the height is 14 mm. Similarly, the cylindrical stator with a rack in a concave shape in Example 1 of the present application is selected, and its diameter is defined as 30 mm and its height is 14 mm. Modal analysis and harmonic response analysis are performed in Workbench finite element software. After preliminary optimization and improvement, under the conditions of 100 V voltage and 0.3% damping ratio, as shown in FIG. Figure 8 As shown, the transverse axis is the frequency, the longitudinal axis is the amplitude, the maximum radial amplitude and the maximum circumferential amplitude of the spur stator structure are 1.9 μm and 1.5 μm respectively, and the stator structure in the preferred embodiment is under the conditions of 100 V voltage and 0.3% damping ratio, Fig. 9 As shown, the transverse axis is the frequency, the longitudinal axis is the amplitude, and the maximum radial amplitude and the maximum circumferential amplitude are 2.2 μm and 4 μm, respectively;

[0045] In order to more intuitively see the difference between the two, the ellipses formed on the radial and circumferential planes on the stator teeth of the stator structure of the present application and the spur-tooth stator structure under their respective optimal conditions are compared, as shown in FIG. Fig.10 As shown, it can be clearly seen that the amplitude of the annular cylindrical stator with the rack in a concave structure is amplified to a certain extent in the radial and circumferential directions.

[0046] Figure 3 It can also be seen that a counterweight structure 2-4-1 for positioning the annular cylindrical stator 2-4 is installed in the thin-sheet annular elastic matrix 2-4-3 structure; a flexible web 2-4-2 is installed in the space between the counterweight structure 2-4-1 and the thin-sheet annular elastic matrix 2-4-3 structure, and the counterweight structure 2-4-1, the flexible web 2-4-2 and the thin-sheet annular elastic matrix 2-4-3 are located in the same plane;

[0047] It should be noted that the counterweight structure 2-4-1 is a fixed installation structure, which is an integral whole with the annular cylindrical stator 2-4 and the flexible web 2-4-2. The integration of the counterweight structure 2-4-1 and the flexible web 2-4-2 can better provide a fixing effect on the annular cylindrical stator 2-4; at the same time, the flexible web 2-4-2 is located in the space between the counterweight structure 2-4-1 and the thin-sheet annular elastic matrix 2-4-3 structure, which makes the fixing method of the in-plane traveling wave type linear ultrasonic motor of the present application more convenient. The setting of the flexible web 2-4-2 also plays an isolation role, and does not affect the direction of the traveling wave on the annular cylindrical stator 2-4, and the driving effect is better.

[0048] Depend on Figure 1In the figure, it can be clearly seen that the mover 1 is an I-shaped long strip structure as a whole. The part where the mover 1 contacts the annular cylindrical stator 2-4 is T-shaped, and the transverse part of the T-shape contacts the rack 2-4-4 on the circumferential surface of the annular cylindrical stator 2-4; after the rack 2-4-4 is subjected to pre-pressure, slight bending deformation will occur. If the contact surface between the mover 1 and the stator is a plane with relatively large rigidity, the middle part of the mover 1 and the rack 2-4-4 cannot be in close contact, resulting in uneven contact between the two. In this embodiment, the contact part between the mover 1 and the stator is set to a T-shape with a certain flexibility. When the mover 1 contacts the stator, as the rack 2-4-4 is slightly bent and deformed, the T-shaped transverse part of the mover 1 can be adjusted according to the shape of the rack 2-4-4, and will also be slightly deformed, and fit closely on the rack 2-4-4, so that the contact is more uniform and the driving ability of the motor is better.

[0049] In this embodiment, two groups of piezoelectric ceramic sheets 2-2a and 2-2b are symmetrically arranged with the circular cylindrical stator 2-4 as the center, one side of the piezoelectric ceramic sheets 2-2a and 2-2b is pasted on the thin circular ring-shaped elastic matrix 2-4-3 adjacent to it, and the piezoelectric ceramic sheets 2-2a and 2-2b groups include a number of piezoelectric ceramic sheets 2-2a and 2-2b connected in sequence, and each group of piezoelectric ceramic sheets 2-2a and 2-2b is in a circular ring shape that matches the structure of the thin circular ring-shaped elastic matrix 2-4-3; preferably, there are 22 piezoelectric ceramic sheets 2-2a and 2-2b in total, and each group of piezoelectric ceramic sheets 2-2a and 2-2b has 11 piezoelectric ceramic sheets, and the surfaces of the piezoelectric ceramic sheets 2-2a and 2-2b are divided into zones for polarization;

[0050] Figure 5 As shown, it is a schematic diagram of partition polarization of two groups of piezoelectric ceramic sheets 2-2a and 2-2b. Taking one of the partition polarization in 5a as an example, one of the piezoelectric ceramic sheets 2-2a and 2-2b in the first group of piezoelectric ceramic sheets 2-2a and 2-2b is selected as a quarter-wavelength partition, and this partition is not polarized. At the same time, the two piezoelectric ceramic sheets 2-2a and 2-2b opposite to this partition are used as three-eighths wavelength partitions. The two piezoelectric ceramic sheets 2-2a and 2-2b of the three-eighths wavelength partitions are adjacent. Four piezoelectric ceramic sheets 2-2a and 2-2b of the half-wavelength partitions are arranged between the piezoelectric ceramic sheets 2-2a and 2-2b of the quarter-wavelength partitions and each piezoelectric ceramic sheet 2-2a and 2-2b of the three-eighths wavelength partitions. Except for the unpolarized quarter-wavelength partitioned piezoelectric ceramic sheets 2-2a and 2-2b, the other piezoelectric ceramic sheets 2-2a and 2-2b are alternately positively and negatively polarized.

[0051] Similarly, another group of piezoelectric ceramic sheets 2-2a and 2-2b use the same polarization method, such as Figure 5 As shown in 5b;

[0052] In the above polarization mode, the so-called alternating positive and negative polarization, the positive sign indicates that the polarization direction is perpendicular to the annular ring surface and is axially outward, that is, toward the adjacent conductive films 2-1a, 2-1b, and the negative sign indicates that the polarization direction is perpendicular to the annular ring surface and is axially inward, that is, toward the annular cylindrical stator 2-4.

[0053] Then, two excitation signals with a time difference of π / 2 are respectively applied to the polarized piezoelectric ceramic sheets 2-2a and 2-2b, so that two modal vibration modes with a time difference of π / 2 in both space and time can be excited, thus forming two modal vibration modes;

[0054] Figure 5 As shown, each group of piezoelectric ceramic sheets 2-2a, 2-2b is divided into A phase and B phase. The A phase in the first group is 2-2a-A, and the B phase is 2-2a-B. The A phase in the second group is 2-2b-A, and the B phase is 2-2b-B. The same sin (wt) electrical signal is passed through 2-2a-A and 2-2b-A, and the cos (wt) electrical signal with a phase difference of π / 2 with the A signal is passed through 2-2a-B and 2-2b-B at the same time. The schematic diagram of the two modal vibration shapes formed is shown in the figure. Figure 4 As shown, an intra-plane wave that moves circumferentially along the circumference can be coupled on the racks 2-4-4 evenly distributed on the circumferential surface of the annular cylindrical stator 2-4. Since the friction material 2-3 is adhered to the tooth surface of one of the racks 2-4-4, the rack 2-4-4 adhered with the friction material 2-3 forms an elliptical motion in the radial and circumferential planes, driving the mover 1 to move.

[0055] Embodiment 2:

[0056] The in-plane traveling wave type linear ultrasonic motor of the above-mentioned embodiment 1 has high versatility and can be used not only for precision platform feeding and miniaturized structures, but also for optical lenses. Preferably, taking the use in platform feeding as an example, a platform feeding device based on the in-plane traveling wave type linear ultrasonic motor is provided, including a machine cover 5, a support member 3, a base 6, a slide rail assembly 7 and a working platform 8. The support member 3 is arranged in a U-shaped structure, the stator assembly 2 is fixed in the U-shaped structure formed by the support member 3, and the closed end of the support member 3 is installed on the machine cover 5; a slide bar is installed on the outward side of the vertical part of the support member 3, and the slide bar The base 6 is parallel to the radial direction of the inner annular cylindrical stator 2-4 of the stator assembly 2, and is also in a U-shaped structure. It is movably sleeved on the support member 3, and slide grooves are respectively provided on the inner sides of the vertical parts of the base 6, and the slide grooves match the slide bars; a slide rail assembly 7 is installed on the transverse part of the base 6, and the bottom of the working platform 8 is movably connected to the transverse part of the base 6 through the slide rail assembly 7; the mover 1 is installed on the side of the working platform 8 opposite to the stator assembly 2, and the part of the mover 1 that contacts the annular cylindrical stator 2-4 is in a T-shape, and the transverse part of the T-shape contacts the circumferential surface of the annular cylindrical stator 2-4;

[0057] A pre-stress adjustment gasket 4 is provided at the connection between the closed end of the support member 3 and the machine cover 5, so as to avoid the problem of uneven pre-stress application, and the size of the pre-stress can be changed by changing the thickness of the pre-stress adjustment gasket 4. The closed end of the support member 3 is made into a flexible structure, and applying pre-stress on such a flexible structure is similar to applying pre-stress by a spring, so that the driving performance of the entire motor is better.

[0058] The aforementioned cover 5 and base 6 are fixedly connected by screws;

[0059] Embodiment 1 is applied to embodiment 2. After the mover 1 moves, it drives the working platform 8 to move. When the phase difference of the phase electrical signal is -90°, the working platform 8 slides in the opposite direction.

[0060] It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as generally understood by those skilled in the art to which this application belongs. It should also be understood that terms such as those defined in common dictionaries should be understood to have meanings consistent with the meanings in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless defined as herein.

[0061] The meaning of "and / or" described in this application means that the situations where each exists alone or both exist at the same time are included.

[0062] The term “connection” as used in this application may mean a direct connection between components or an indirect connection between components via other components.

[0063] Based on the above ideal embodiments of the present invention, the relevant staff can make various changes and modifications without departing from the technical concept of the present invention through the above description. The technical scope of the present invention is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. An in-plane traveling wave linear ultrasonic motor, comprising a stator assembly and a mover, characterized in that: The stator assembly is a cylindrical structure as a whole, which includes a circular cylindrical stator, a plurality of racks are evenly arranged on the circumferential surface of the circular cylindrical stator, and two symmetrical thin circular ring-shaped elastic substrates are respectively arranged on the two end surfaces of the circular cylindrical stator; It also includes two groups of piezoelectric ceramic sheets symmetrically arranged around the annular cylindrical stator, one side of each group of piezoelectric ceramic sheets is connected to a thin annular elastic matrix, a conductive film is arranged on the other side of each group of piezoelectric ceramic sheets, and the thin annular elastic matrix is ​​located between the annular cylindrical stator and the piezoelectric ceramic sheet group; Partition polarization on the surface of piezoelectric ceramics; The mover is arranged in a long strip shape, suspended on the circumferential surface of the annular cylindrical stator, and the part where the mover contacts the annular cylindrical stator is in a T shape, and the transverse part of the T shape contacts the circumferential surface of the annular cylindrical stator; A counterweight structure for positioning the annular cylindrical stator is installed in the thin annular elastic base structure; A flexible web is installed in the space between the counterweight structure and the thin circular ring-shaped elastic base structure, and the counterweight structure, the flexible web and the thin circular ring-shaped elastic base are located in the same plane; A plurality of racks are evenly arranged on the circumferential surface of the annular cylindrical stator, each rack is arranged in a concave shape, and its opening portion faces the center of the annular cylindrical stator; Apply friction material to the tooth surface of one of the racks.

2. The in-plane traveling wave linear ultrasonic motor according to claim 1, characterized in that: The piezoelectric ceramic sheet group includes a plurality of piezoelectric ceramic sheets connected in sequence, and each piezoelectric ceramic sheet group is in a circular ring shape matching the circular ring-shaped elastic matrix structure of the thin sheet; One side of the piezoelectric ceramic sheet is adhered to a thin circular elastic substrate adjacent to the piezoelectric ceramic sheet, and a plurality of piezoelectric ceramic sheets are divided into a plurality of polarization partitions.

3. A platform feeding device of the in-plane traveling wave linear ultrasonic motor according to claim 1, comprising a machine cover, a support member, a base, a slide rail assembly and a working platform, characterized in that: The support member is arranged in a U-shaped structure, the stator assembly is fixed in the U-shaped structure formed by the support member, and the closed end of the support member is mounted on the machine cover; A slide bar is installed on the outward side of the vertical part of the support, and the slide bar is parallel to the radial direction of the inner cylindrical stator of the stator assembly. The base is also a U-shaped structure, which can be movably sleeved on the support, and slide grooves are respectively provided on the inner side of the vertical part of the base, and the slide grooves match the slide bar; A slide rail assembly is installed on the transverse part of the base, and the bottom of the working platform is movably connected to the transverse part of the base through the slide rail assembly; The mover is installed on the side of the working platform opposite to the stator assembly, and the part of the mover contacting the annular cylindrical stator is T-shaped, and the transverse part of the T-shape contacts the circumferential surface of the annular cylindrical stator.

4. The platform feeding device of the in-plane traveling wave linear ultrasonic motor according to claim 3, characterized in that: A pre-pressure adjustment gasket is arranged at the connection between the closed end of the support member and the machine cover.

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