JP7814414B2 - Piezoelectric micromotor and its manufacturing method - Google Patents

Description

The present invention relates to the field of piezoelectric motors, and more particularly to piezoelectric micromotors and methods for manufacturing the same.

In related technology, unlike conventional electromagnetic motors, piezoelectric motors are motors based on a novel principle. Piezoelectric motors use the inverse piezoelectric effect of piezoelectric ceramics to cause micro-vibrations in the stator, and the friction at the contact interface between the stator and rotor converts the micro-vibrations of the stator into macro-motion of the rotor. Therefore, piezoelectric motors have the advantages of a compact structure, no electromagnetic interference, ease of miniaturization, and high energy density. These features allow piezoelectric motors to be applied in many fields, including digital cameras, biomedical therapy, aerospace equipment, and precision systems.

However, piezoelectric micromotors manufactured using machined methods have a dimensional limit, and motor performance drops sharply below a certain size.

The present invention provides a piezoelectric micromotor and a method for manufacturing the same.

A piezoelectric micromotor provided in a first aspect of an embodiment of the present invention includes a stator and a rotor, the stator including a control deformation portion, a passive deformation portion, and a group of transmission links;
At least one rotor through-hole is provided in the controlled deformation portion and the passive deformation portion, and the rotor is provided in the rotor through-hole;
The control deformation unit is further provided with an inverse piezoelectric unit for generating deformation,
the power transmission link group is located between the control deformation section and the passive deformation section, the power transmission link group includes at least two power transmission links, both ends of the power transmission links are connected to the control deformation section and the passive deformation section, respectively;
The control deformation portion, the passive deformation portion, and the power transmission link group are integrally formed.

In some embodiments, the controlled deformation section includes a first controlled deformation section and a second controlled deformation section, the transmission link group includes a first link group and a second link group, the first link group is located between the first controlled deformation section and the passive deformation section, the second link group is located between the second controlled deformation section and the passive deformation section, and the first controlled deformation section and the second controlled deformation section are installed symmetrically on both sides of the passive deformation section.

In some embodiments, the first control deformation portion and the second control deformation portion are rectangular, the inverse piezoelectric portion is located on four sides of the first control deformation portion and the second control deformation portion, and the four corners of the first control deformation portion and the second control deformation portion are arc-shaped.

In some embodiments, the inverse piezoelectric sections are adapted to generate deformations when receiving excitation signals, and two opposing inverse piezoelectric sections in each of the control deformation sections are a pair, and the two pairs of inverse piezoelectric sections in each of the control deformation sections are adapted to receive a cosine excitation signal and a sine excitation signal, respectively;
The frequency of the excitation signal is within the resonant excitation range of the controlled deformation unit, whereby two resonant modes of the stator are excited, and the resonant vibration of the stator drives the rotor.

In some embodiments, the resonant excitation range of the controlled deformation portion is 393.368 kHz to 393.871 kHz.

In some embodiments, the direction of the control deformation portion directed to the passive deformation portion is a lateral direction, and the direction perpendicular to the lateral direction is a longitudinal direction, and in this case, the frequency of the excitation signal may not be close to the resonance frequency of the operating mode, and the stator forms an elliptical motion locus at the driving point due to non-resonance;
the inverse piezoelectric portion located in the first control deformation portion includes a first set and a second set, the first set being located on a horizontal side of the first control deformation portion and the second set being located on a vertical side of the first control deformation portion; the inverse piezoelectric portion located in the second control deformation portion includes a third set and a fourth set, the third set being located on a horizontal side of the second control deformation portion and the fourth set being located on a vertical side of the second control deformation portion;
The first and fourth sets are used to receive a sinusoidal excitation signal, and the second and third sets are used to receive a cosine excitation signal, or the first and fourth sets are used to receive a cosine excitation signal, and the second and third sets are used to receive a sinusoidal excitation signal.

In some embodiments, the piezoelectric micromotor further comprises microteeth;
The microteeth are installed within the rotor through-hole and positioned between the stator and the rotor, the microteeth are installed on at least one of the stator and the rotor, and the stator contacts the rotor via the microteeth.

In some embodiments, the microteeth are evenly distributed and the spacing between adjacent microteeth is an integer multiple of the wavelength, where the wavelength follows the formula λ = v × T, where λ is the wavelength, v is the speed of sound in the stator or rotor, and T is the period over which the sinusoidal excitation signal is applied.

In some embodiments, the piezoelectric micromotor further comprises a micro-drive structure;
The micro-actuating structure includes a conductive post and a micro-actuating circuit, the micro-actuating circuit is mounted on a flexible carrier board, one end of the conductive post is electrically connected to the micro-actuating circuit, and the other end is electrically connected to the inverse piezoelectric portion.

A method for manufacturing a piezoelectric micromotor provided in a second aspect of an embodiment of the present invention includes providing a base;
laser cutting the base to form a stator base, and plating a 0.01 mm to 0.1 mm thick inverse piezoelectric portion on the stator base using magnetron sputtering technology;
After forming the inverse piezoelectric portion, polarizing the inverse piezoelectric portion by a polarization process to form a stator;
providing a flexible carrier board after poling the inverse piezoelectric portion;
forming a micro-drive circuit on the flexible carrier board to form a micro-drive structure;
and electrically connecting pads of the micro-drive circuit to the inverse piezoelectric portion.

In some embodiments, forming the inverse piezoelectric portion on the stator base by plating using a magnetron sputtering technique and polarizing the inverse piezoelectric portion by a polarization process includes:
placing a polymer mask plate on the stator base, and plating the inverse piezoelectric portion on the stator base using magnetron sputtering technology;
After forming the inverse piezoelectric portion, the polymer mask plate is removed, and the inverse piezoelectric portion is polarized by a corona polarization process.

In some embodiments, after poling the inverse piezoelectric portion by a poling process,
a polymer mask plate is placed on the stator, and a rotor is formed in the rotor through-hole by plating using a magnetron sputtering technique;
The method further includes removing the polymer mask plate after forming the rotor.

In some embodiments, after forming the rotor,
attaching a preload structure to the stator;
forming a micro driver circuit on a flexible carrier board by inkjet printing;
placing a solid sleeve on a pad of the micro-drive circuit, the hollow portion of the solid sleeve being aligned with the pad of the micro-drive circuit;
pouring a conductive adhesive into the solid sleeve;
removing the solid sleeve after the conductive adhesive has solidified, and grinding the solidified conductive adhesive to form conductive posts;
The method further includes electrically connecting the other end of the conductive post to the inverse piezoelectric portion.

According to an embodiment of the present invention, when the dimensions of a piezoelectric micromotor are on the order of millimeters or less, if each part of the stator is formed separately and then assembled, errors will occur during the processing of each part, resulting in a larger processing error after assembly. After extensive experiments, the inventors discovered that even a processing error of 0.1 millimeters on the order of substrates will prevent the piezoelectric micromotor from operating stably. By integrally forming the control deformation part, passive deformation part, and transmission link group, the processing error of the entire stator can be effectively reduced, thereby meeting the processing requirements of millimeter- to micrometer-level piezoelectric micromotors.

It is to be understood that the foregoing general description and the following detailed description are merely exemplary and explanatory and are not intended to limit the invention.

The drawings herein, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present invention and, together with the specification, serve to explain the principles of the invention.
1 is a structural schematic diagram of a piezoelectric micromotor according to an embodiment of the present invention; 2 is a structural schematic diagram of a stator according to an embodiment of the present invention; FIG. 3 is a structural schematic diagram of a control deformation unit according to an embodiment of the present invention; FIG. 5A and 5B are schematic diagrams illustrating the amount of deformation at various locations of a stator according to an embodiment of the present invention. 10A and 10B are schematic diagrams illustrating the amounts of deformation at various locations of another stator according to an embodiment of the present invention. 1 is a local enlarged view of a portion located in a control deformation portion of a piezoelectric micromotor according to an embodiment of the present invention. 1 is a structural schematic diagram of a micro-actuation structure shown in an embodiment of the present invention; 1 is a structural schematic diagram of a micro-drive circuit shown in an embodiment of the present invention; 1 is a flowchart of a method for manufacturing a piezoelectric micromotor according to an embodiment of the present invention.

Illustrative embodiments will now be described in detail, examples of which are illustrated in the drawings. In the following description, when referring to the drawings, identical numerals in different drawings refer to identical or similar elements unless otherwise indicated. The embodiments described in the illustrative examples below do not represent all embodiments consistent with the present invention. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present invention, as detailed in the appended claims.

An embodiment of the present invention provides a piezoelectric micromotor 10, and FIG. 1 shows a schematic structural diagram of the piezoelectric micromotor 10. As shown in FIG. 1, the piezoelectric micromotor 10 includes a stator 11 and a rotor 12.

The stator 11 includes a control deformation section 13, a passive deformation section 14, and a transmission link group 15.

At least one rotor through-hole 16 is provided in the controlled deformation section 13 and the passive deformation section 14, and the rotor 12 is installed within the rotor through-hole 16.

Specifically, at least one rotor through-hole 16 is provided in each of the controlled deformation section 13 and the passive deformation section 14. That is, one or more rotor through-holes 16 may be provided only in the controlled deformation section 13, or one or more rotor through-holes 16 may be provided only in the passive deformation section 14, or one or more rotor through-holes 16 may be provided in both the controlled deformation section 13 and the passive deformation section 14. Different installation methods for the rotor through-holes 16 and the rotor 12 allow for flexible adjustment of the number of loads accessing the piezoelectric micromotor 10, and also allow for flexible adjustment so that loads with different parameters can access the piezoelectric micromotor 10, thereby expanding the usage scenarios and range of the piezoelectric micromotor 10.

The controlled deformation section 13 further includes an inverse piezoelectric section 17 for generating deformation.

The transmission link group 15 is located between the control deformation section 13 and the passive deformation section 14. The transmission link group 15 includes at least two transmission links 151, and both ends of the transmission link 151 are connected to the control deformation section 13 and the passive deformation section 14, respectively.

Specifically, the inverse piezoelectric portion 17 is made of a piezoelectric material, which may include, but is not limited to, piezoelectric ceramic. Therefore, when the inverse piezoelectric portion 17 receives an excitation signal, it generates a continuously changing deformation under the action of the excitation signal. The deformed inverse piezoelectric portion 17 drives the control deformation portion 13 to generate a continuously changing deformation, and the deformation of the control deformation portion 13 drives the rotor through-hole 16 to generate a continuously changing deformation. As a result, the rotor through-hole 16, which generates a continuously changing deformation, rotates the rotor 12, and the load connected to the piezoelectric micromotor 10 can be driven.

Moreover, the deformation of the controlled deformation unit 13 is transmitted to the passive deformation unit 14 via the transmission link group 15, causing the passive deformation unit 14 to move. This allows the deformation of the controlled deformation unit 13 and the passive deformation unit 14 to drive multiple rotor through holes 16, simultaneously causing constantly changing deformation. This ultimately rotates multiple rotors 12 via the rotor through holes 16 that cause constantly changing deformation, allowing multiple loads connected to the piezoelectric micromotor 10 to be driven.

On the other hand, Figure 2 shows a schematic structural diagram of the stator 11. As shown in Figure 1, referring to Figure 2, the controlled deformation portion 13 of the stator 11 may be rectangular or cross-shaped, but is not limited to these, and the shape of the controlled deformation portion 13 may be other shapes that are easily deformed by the action of the inverse piezoelectric portion 17.

The control deformation section 13, the passive deformation section 14, and the transmission link group 15 are integrally formed.

Specifically, the term "integrally formed" referred to in this invention means that there is no need to form the controlled deformation section 13, the passive deformation section 14, and the transmission link group 15 separately and then perform an assembly process, and the controlled deformation section 13, the passive deformation section 14, and the transmission link group 15 are formed by processing the same material.

When the dimensions of the piezoelectric micromotor 10 are millimeter-level or less, if each part of the stator 11 is formed separately and then assembled, errors will occur during the processing of each part, resulting in a larger processing error after assembly. After extensive experimentation, the inventors discovered that for piezoelectric micromotors 10 with dimensions in the 1-5 mm range, even a processing deviation of 0.1 mm for the substrate will prevent the piezoelectric micromotor 10 from operating stably. By integrally forming the control deformation section 13, passive deformation section 14, and transmission link group 15, the processing error of the entire stator 11 can be effectively reduced, thereby meeting the processing requirements of piezoelectric micromotors 10 on the millimeter to micrometer scale.

In some embodiments, as shown in FIG. 1, the controlled deformation section 13 and the passive deformation section 14 are located on the same central axis X. The center of each rotor through hole 16 may also be located on the central axis X.

Specifically, when the controlled deformation section 13 and the passive deformation section 14 are not deformed, the rotor through hole 16 is circular, and the center of the rotor through hole 16 is the center of the circle. When the controlled deformation section 13 and the passive deformation section 14 are deformed, the rotor through hole 16 is elliptical, and the center of the rotor through hole 16 is the intersection of the major and minor axes of the ellipse.

Note that while the center of each rotor through hole 16 being located on the central axis X is merely a possible embodiment of the present invention, in other embodiments of the present invention, depending on actual requirements, the centers of some of the rotor through holes 16 may be located on the central axis X, and the centers of some of the rotor through holes 16 may not be located on the central axis X, or none of the centers of all the rotor through holes 16 may be located on the central axis X, or all of the centers of the rotor through holes 16 may be located on the central axis X.

In some embodiments, as shown in FIG. 1, the piezoelectric micromotor 10 further includes a preload structure 19. The preload structure 19 is used to maintain the relative fixation of the stator 11. Maintaining the relative fixation of the stator 11 using the preload structure 19 allows the relative fixation of all other structures connected to the stator 11, thereby maintaining normal operation of the piezoelectric micromotor 10 and preventing other structures from interfering with the stator 11 and interfering with the deformation range of the stator 11.

The preload structure 19 includes a bezel 191, a fastening nut 192, and a disc spring 193.

The fastening nut 192 is threaded onto the bezel 191. The preload structure 19 is used to maintain the relative fixation of the stator 11; that is, the fastening nut 192 adjusts the distance between it and the passive deformation portion 14, maintaining a distance that allows the disc spring 193 to generate elastic force without being excessively compressed. Moreover, the disc spring 193 still maintains a certain amount of space for elastic deformation, so it does not excessively interfere with the deformation generated by the passive deformation portion 14.

At the same time, the deformation amplitude generated by the passive deformation section 14 is smaller than that generated by the controlled deformation section 13. Therefore, by positioning the pressing position of the preload structure 19 at the passive deformation section 14, the effect of the preload structure 19 on the deformation amplitude of the stator 11 can be minimized.

In some embodiments, as shown in FIG. 1, the transmission link 151 forms an angle α with the central axis X. When installed in this manner, the deformation generated by the control deformation unit 13 can be amplified and transmitted to the passive deformation unit 14 via the transmission link group 15 according to the principle of triangular expansion, thereby allowing the control deformation unit 13 and the passive deformation unit 14 to be used to drive loads with different requirements.

In this embodiment, the deformation generated by the control deformation unit 13 is expanded via the transmission link group 15 based on the principle of triangular expansion and transmitted to the passive deformation unit 14. However, this is not limited to this. In other embodiments, the deformation generated by the control deformation unit 13 is reduced via the transmission link group 15 and transmitted to the passive deformation unit 14, and the control deformation unit 13 and passive deformation unit 14 are used to drive loads with different requirements.

In some embodiments, as shown in FIG. 1, the controlled deformation section 13 includes a first controlled deformation section 131 and a second controlled deformation section 132. The power transmission link group 15 includes a first link group 152 and a second link group 153. The first link group 152 is located between the first controlled deformation section 131 and the passive deformation section 14, and the second link group 153 is located between the second controlled deformation section 132 and the passive deformation section 14. The first controlled deformation section 131 and the second controlled deformation section 132 are installed symmetrically on both sides of the passive deformation section 14.

By arranging the first control deformation section 131 and the second control deformation section 132 symmetrically on both sides of the passive deformation section 14, the force applied to the passive deformation section 14 can be made more uniform, thereby reducing the situation in which the deformation caused by uneven force applied to the passive deformation section 14 differs from the deformation of the control deformation section 13, thereby improving the stability of the passive deformation section 14 and the operating stability of the entire piezoelectric micromotor 10.

In some embodiments, Figure 3 shows a schematic structural diagram of the controlled deformation portion 13. As shown in Figures 1 and 3, the first controlled deformation portion 131 and the second controlled deformation portion 132 are rectangular. The inverse piezoelectric portion 17 is located on the four sides of the first controlled deformation portion 131 and the second controlled deformation portion 132, and the four corners of the first controlled deformation portion 131 and the second controlled deformation portion 132 may be arc-shaped.

Specifically, in this embodiment, the inverse piezoelectric portion 17 is installed symmetrically on the four sides of the first controllable deformation portion 131 and the second controllable deformation portion 132. FIG. 1 shows the central axis X, the first axis Y1 of the first controllable deformation portion 131, and the second axis Y2 of the second controllable deformation portion 132. The inverse piezoelectric portion 17 installed opposite the first controllable deformation portion 131 is symmetrical with respect to the central axis X or the first axis Y1, and the inverse piezoelectric portion 17 installed opposite the second controllable deformation portion 132 is symmetrical with respect to the central axis X or the second axis Y2.

Figures 4 and 5 show schematic diagrams of the amount of deformation at various points on the stator 11 after the first control deformation section 131 and the second control deformation section 132 have deformed, based on the results of simulation experiments conducted by the inventors. Referring to Figures 4 and 5, the inverse piezoelectric section 17 is located on the four sides of the first control deformation section 131 and the second control deformation section 132. After the inverse piezoelectric section 17 receives an excitation signal and deforms, different deformation states occur, driving the control deformation section 13 to deform. As is clear from Figures 4 and 5, the inverse piezoelectric section 17 is the portion of the stator 11 that deforms the most.

After the controlled deformation section 13 is deformed, the rotor through-hole 16 becomes elliptical due to the deformation of the controlled deformation section 13. By controlling the inverse piezoelectric sections 17 on the four sides of the first controlled deformation section 131 or the second controlled deformation section 132, the deformation state of the first controlled deformation section 131 or the second controlled deformation section 132 can be adjusted, and the elliptical shape formed by the deformation of the rotor through-hole 16 can be rotated around its center, thereby achieving the effect of rotating the rotor 12.

As can be further observed from Figures 4 and 5, there are clearly small deformation areas at the four corners of the control deformation section 13, i.e., the dark areas shown in regions Q1, Q2, Q3, Q4, and Q5 in Figures 4 and 5. By arranging the four corners of the first control deformation section 131 and the second control deformation section 132 in an arc shape, the small deformation areas at the four corners of the first control deformation section 131 and the second control deformation section 132 can be reduced, thereby increasing the amount of deformation generated by the control deformation section 13 while generating the same amount of deformation in the inverse piezoelectric section 17, and ultimately improving the operating efficiency of the stator 11 and the entire piezoelectric micromotor 10.

Note that due to viewpoint issues, Figures 4 and 5 cannot show the deformation amounts of all corners of the first control deformation section 131 and the second control deformation section 132, but for the remaining corners for which deformation amounts are not shown, you can still refer to the deformation amounts of the shown corners.

In some embodiments, the inverse piezoelectric sections 17 are used to generate deformation upon receiving an excitation signal. There are two opposing inverse piezoelectric sections 17 in each control deformation section 13, and the two sets of inverse piezoelectric sections 17 in each control deformation section 13 are used to receive a cosine excitation signal and a sine excitation signal, respectively.

The frequency of the excitation signal is greater than or equal to 393.368 kHz and less than or equal to 393.871 kHz.

Specifically, as shown in FIG. 1, the two opposing inverse piezoelectric elements 17 in the controlled deformation section 13 form a pair. That is, in the first controlled deformation section 131, the inverse piezoelectric elements 17 located on both sides of the first axis Y1 form a pair, and the inverse piezoelectric elements 17 located on both sides of the central axis X form a separate pair. Similarly, in the second controlled deformation section 132, the inverse piezoelectric elements 17 located on both sides of the second axis Y2 form a pair, and the inverse piezoelectric elements 17 located on both sides of the central axis X form a separate pair.

The frequency of the excitation signal is greater than or equal to 393.368 kHz and less than or equal to 393.871 kHz. When the excitation signal is within this range, it is exactly within the resonant excitation range of the two control deformation units 13. This allows the amount of deformation after receiving the excitation signal to be improved by the resonant excitation of the control deformation units 13, thereby improving parameters such as the rotation speed and output torque of the entire piezoelectric micromotor 10.

In some embodiments, as shown in FIG. 1, the direction of the controlled deformation portion 13 directed toward the passive deformation portion 14 is the horizontal direction Z1, and the direction perpendicular to the horizontal direction Z1 is the vertical direction Z2.

The inverse piezoelectric element 17 located in the first controlled deformation section 131 includes a first set 171 and a second set 172, with the first set 171 located on the horizontal Z1 side of the first controlled deformation section 131 and the second set 172 located on the vertical Z2 side of the first controlled deformation section 131. The inverse piezoelectric element 17 located in the second controlled deformation section 132 includes a third set 173 and a fourth set 174, with the third set 173 located on the horizontal Z1 side of the second controlled deformation section 132 and the fourth set 174 located on the vertical Z2 side of the second controlled deformation section 132.

The first set 171 and the fourth set 174 are used to receive a sine excitation signal, and the second set 172 and the third set 173 are used to receive a cosine excitation signal, or the first set 171 and the fourth set 174 are used to receive a cosine excitation signal, and the second set 172 and the third set 173 are used to receive a sine excitation signal.

When installed in this manner, the frequency of the excitation signal is within the range of 393.368 kHz to 393.871 kHz, and by inputting the excitation signal to the inverse piezoelectric unit 17 in the above manner, two resonant modes of the controlled deformation unit 13 can be excited simultaneously. This allows the amount of deformation after receiving the excitation signal to be further improved by the resonant excitation of the controlled deformation unit 13, and ultimately further improves parameters such as the rotation speed and output torque of the entire piezoelectric micromotor 10.

Furthermore, the frequency of the excitation signal does not have to be within the range of 393.368 kHz to 393.871 kHz. In this case, if the excitation signal is still applied in the above manner, the inverse piezoelectric elements of the first set 171 and the fourth set 174 are excited by the electrical signal to generate vertical vibrations, and the inverse piezoelectric elements of the second set 172 and the third set 173 are excited by the electrical signal to generate horizontal vibrations. The superposition of the vibrations in the two directions can similarly form an elliptical motion that can drive the rotor to rotate. However, in this case, the piezoelectric micromotor operates in a non-resonant state.

Note that the amount of deformation of the passive deformation section 14 shown in Figure 4 is smaller than the amount of deformation of the passive deformation section 14 shown in Figure 5, but this is actually a simulation obtained by the inventors under different data conditions. Therefore, the difference in the amount of deformation between Figures 4 and 5 does not contradict the effect of this embodiment.

In some embodiments, the transmission link group 15 includes at least one of a flexible hinge, a horn, and a rigid link. This arrangement allows the transmission link group 15 to better achieve its displacement amplification function, i.e., the amount of deformation transmitted by the transmission link group 15 to the passive deformation unit 14 can be closer to a preset value. This can further improve the amount of deformation generated by the passive deformation unit 14 when the inverse piezoelectric unit 17 generates the same amount of deformation, thereby further improving the operating efficiency of the stator 11 and the entire piezoelectric micromotor 10.

In some embodiments, as shown in FIG. 1, the piezoelectric micromotor 10 further includes microteeth 18.

The microteeth 18 are installed in the rotor through-hole 16 and are located between the stator 11 and the rotor 12. The microteeth 18 are installed on at least one of the stator 11 and the rotor 12. The stator 11 contacts the rotor 12 via the microteeth 18.

Specifically, the microteeth 18 may be provided only on the stator 11 as shown in FIG. 1, or the microteeth 18 may be provided only on the rotor 12, or the microteeth 18 may be provided on both the stator 11 and the rotor 12.

Furthermore, by bringing the stator 11 into contact with the rotor 12 via the microteeth 18, the active area of the stator 11 relative to the rotor 12 can be increased. Specifically, Figure 6 shows a localized enlargement of the portion located at the control deformation section 13 of the piezoelectric micromotor 10. Referring to Figure 6, taking the situation where the microteeth 18 are located on the stator 11 as an example, when the rotor through-hole 16 becomes elliptical, the minor axis of the ellipse is shorter than the diameter of the circular rotor through-hole 16 before deformation, and the microteeth 18 are pressed against the rotor 12, thereby increasing the active area of the rotor through-hole 16 relative to the rotor 12.

Note that the gap between the stator 11 and rotor 12 shown in the figure is relatively large to visually show the microteeth 18. However, in reality, if the microteeth 18 themselves are small and the rotor through-hole 16 is elliptical in shape, the materials of the stator 11 and rotor 12 are flexible, allowing the stator 11 to come into contact with the rotor 12.

By having the stator 11 contact the rotor 12 via the microteeth 18, the active area of the stator 11 relative to the rotor 12 can be increased, thereby improving the efficiency of power transmission from the stator 11 to the rotor 12 and ultimately improving the performance of the piezoelectric micromotor 10.

In some embodiments, the microteeth 18 are evenly spaced and the spacing between adjacent microteeth 18 is an integer multiple of the wavelength. The wavelength follows the formula λ = v × T, where λ is the wavelength, v is the speed of sound in the stator 11 or rotor 12, and T is the period over which the sinusoidal excitation signal is applied.

Specifically, when the microteeth 18 are installed only on the stator 11, v is the speed of sound within the stator 11. When the microteeth 18 are installed only on the rotor 12, v is the speed of sound within the rotor 12.

By simultaneously aligning the microteeth 18 with the above distribution rules, the stator 11 can be in better contact with the rotor 12 via the microteeth 18, increasing the active area of the stator 11 relative to the rotor 12, thereby further improving the efficiency of power transmission from the stator 11 to the rotor 12 and ultimately further improving the performance of the piezoelectric micromotor 10.

In some embodiments, Figure 7 shows a structural schematic diagram of the micro-actuation structure 20, where the flexible carrier board 21 is a hollow rectangular plate-like structure. As shown in Figure 7, the piezoelectric micromotor 10 further includes the micro-actuation structure 20.

Referring to Figure 8, a schematic structural diagram of the micro-drive circuit 23 is shown. The micro-drive structure 20 includes conductive posts 22 and a micro-drive circuit 23. The micro-drive circuit 23 is mounted on a flexible carrier board 21. One end of the conductive posts 22 is electrically connected to the micro-drive circuit 23, and the other end is electrically connected to the inverse piezoelectric portion 17.

Specifically, area Q6 shown in Figure 7 is used to refer to parts such as the stator 11, rotor 12, controlled deformation section 13, passive deformation section 14, transmission link group 15, rotor through-hole 16, inverse piezoelectric section 17, microteeth 18, and preload structure 19 of the piezoelectric micromotor 10.

Furthermore, as shown in FIG. 7 , the frame of the flexible carrier board 21 is a hollow rectangular plate-like structure, and the flexible carrier board 21 surrounds the stator 11. The micro-drive circuit 23 is a flexible composite circuit board, and includes not only rigid devices such as a drive control chip dedicated to the low-voltage drive piezoelectric micro-motor, chip resistors, capacitors, and inductances, but also pads and lead wires, etc., all of which are integrated on the flexible carrier board 21. The flexible carrier board 21 employs a flexible base material, such as, but not limited to, polyimide, polyethylene, or polyethylene terephthalate. Integrating the micro-drive structure 20 on the piezoelectric micro-motor 10 achieves integration of the motor and drive parts of the piezoelectric micro-motor 10, thereby improving the degree of integration of the piezoelectric micro-motor 10.

Each device of the microdrive circuit 23, such as the lead wires and pads, is formed on the flexible carrier board 21 using an electrofluidic inkjet printing method, thereby enabling the formation of a finer microdrive circuit 23 structure.

While the hollow rectangular flexible carrier board 21 employed in the embodiments of the present invention is a viable embodiment, other embodiments are not limited thereto. For example, the flexible carrier board 21 may be an entirely rectangular flexible carrier board, and the micro-drive structure 20 may be stacked in layers and installed on the piezoelectric micro-motor 10. In this case, referring to the structural schematic diagram of the micro-drive circuit 23 shown in Figure 8, the first pad 40, second pad 41, third pad 42, and fourth pad 43 on the micro-drive circuit 23 to be connected to the piezoelectric ceramic in the piezoelectric micro-motor 10 are positioned parallel to the inverse piezoelectric portion 17 in the first control deformation portion 131 or the second control deformation portion 132. The first pad 40, the second pad 41, the third pad 42, and the fourth pad 43 may be arranged in a rectangular shape, and the conductive posts 22 are electrically connected to the corresponding pads and the inverse piezoelectric portion 17, thereby simultaneously realizing circuit conduction and supporting the micro-actuating structure 20 via the conductive posts 22.

An embodiment of the present invention further provides a method for manufacturing a piezoelectric micromotor 10, and FIG. 9 shows a flowchart of the method for manufacturing a piezoelectric micromotor 10. As shown in FIG. 9, the method for manufacturing the piezoelectric micromotor 10 includes steps S110 to S140.

In step S110, the base is provided.

In step S120, the base is laser cut to form the stator base, and a 0.01 to 0.1 mm thick inverse piezoelectric portion is plated onto the stator base using magnetron sputtering technology.

Specifically, the stator base includes a first control deformation section 131, a second control deformation section 132, a passive deformation section 14, and a transmission link group 15.

In step S130, after the inverse piezoelectric element 17 is formed, the inverse piezoelectric element 17 is polarized using a polarization process to form the stator 11.

In step S140, after the inverse piezoelectric portion 17 is polarized, a flexible carrier board 21 is provided. A micro-drive circuit 23 is formed on the flexible carrier board 21 to form the micro-drive structure 20. The pads of the micro-drive circuit 23 are electrically connected to the inverse piezoelectric portion 17.

By installing it in this manner, the stator 11 can be formed using a one-piece molding method, i.e., the control deformation section 13, the passive deformation section 14, and the transmission link group 15 can be formed as a single unit, thereby meeting the processing requirements of the piezoelectric micromotor 10 on the millimeter to micrometer scale, and ultimately reducing processing errors in each part to ensure stable operation of the piezoelectric micromotor 10.

In some embodiments, plating the inverse piezoelectric portion 17 on the stator base by magnetron sputtering technology and poling the inverse piezoelectric portion 17 by a poling process may include:
The method includes placing a polymer mask plate on a stator base, plating an inverse piezoelectric portion 17 on the stator base by magnetron sputtering technology, and removing the polymer mask plate after forming the inverse piezoelectric portion 17, and polarizing the inverse piezoelectric portion 17 by a corona polarization process.

Since the dimensions of the stator base are small, the dimensions of the inverse piezoelectric portion 17 are also small, requiring greater precision. The inverse piezoelectric portion 17 can be deposited directly onto the stator base using a polymer mask plate and magnetron sputtering, allowing the inverse piezoelectric portion 17 to be formed with small tolerances and meeting the tolerance requirements for the inverse piezoelectric portion 17 of the piezoelectric micromotor 10. Furthermore, by directly depositing the inverse piezoelectric portion 17, the assembly process is omitted compared to manufacturing and assembling the inverse piezoelectric portion 17 separately, further reducing tolerances.

In some embodiments, after the polarization process has been performed to polarize the inverse piezoelectric portion 17,
The method further includes placing a polymer mask plate on the stator 11, plating the rotor 12 in the rotor through-hole 16 using magnetron sputtering technology, and removing the polymer mask plate after the rotor 12 is formed.

Specifically, when the rotor 12 is formed by plating inside the rotor through-hole 16, a gap exists between the rotor 12 and the rotor through-hole 16. Therefore, the rotor 12 formed by plating can be held independent of the rotor through-hole 16. Furthermore, some of the material that falls into the gap between the rotor 12 and the rotor through-hole 16 can be removed in a later process without affecting the machining accuracy of the stator 11 and rotor 12.

Since the dimensions of the stator 11 are small, the dimensions of the rotor 12 are also small, requiring greater precision. The rotor 12 can be formed by depositing it directly onto the stator 11 using a polymer mask plate and magnetron sputtering, allowing the rotor 12 to be formed with small tolerances and meeting the tolerance requirements for the rotor 12 of the piezoelectric micromotor 10. Furthermore, by directly depositing the rotor 12, the assembly process is omitted compared to manufacturing and assembling the rotor 12 separately, further reducing tolerances.

In some embodiments, after forming the rotor 12,
Attaching a preload structure 19 to the stator 11; forming a micro-drive circuit 23 on a flexible carrier board 21 by inkjet printing;
The method further includes placing a solid sleeve on a pad of the micro-drive circuit 23, with the hollow portion of the solid sleeve aligned with the pad of the micro-drive circuit 23; pouring a conductive adhesive into the solid sleeve; removing the solid sleeve after the conductive adhesive has solidified; grinding the solidified conductive adhesive to form a conductive post 22; and electrically connecting the other end of the conductive post 22 to the inverse piezoelectric portion 17.

Specifically, the micro-drive circuit 23 includes a first pad 40, a second pad 41, a third pad 42, and a fourth pad 43. The installed solid sleeve may be, but is not limited to, a hollow rectangular sleeve with a height of 1.5 mm. Here, the conductive adhesive may be, but is not limited to, an epoxy-based conductive adhesive, specifically, E-Solder 3022.

Using this method, the micro-drive structure 20 can be manufactured and obtained. By integrating the micro-drive circuit 23 within the flexible carrier board 21, the micro-drive structure 20 can be integrated into the piezoelectric micro-motor 10, thereby realizing integration of the motor portion and drive portion of the piezoelectric micro-motor 10 and improving the degree of integration of the piezoelectric micro-motor 10.

The above-described embodiments of the present invention can complement each other in a manner that does not result in any contradictions.

In the drawings, the dimensions of layers and regions may be exaggerated for clarity of illustration. It is understood that when an element or layer is referred to as being "on" another element or layer, it may be located directly on the other element, or there may be intermediate layers. It is understood that when an element or layer is referred to as being "below" another element or layer, it may be located directly below the other element, or there may be one or more intermediate layers or elements. It is understood that when an element or layer is referred to as being "between" two layers or elements, it may be the only layer between the two layers or elements, or there may be one or more intermediate layers or elements. Like reference numerals refer to like elements throughout this specification.

The term "plurality" refers to two or more unless otherwise specified.

Other implementations of the present invention will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure herein. The present invention is intended to include any modification, use, or adaptation of the present invention, which modification, use, or adaptation follows from the general principles of the present invention and includes means known or commonly used in the art that are not disclosed herein. The specification and examples are considered exemplary only, with the true scope and spirit of the invention being indicated by the following claims.

It will be understood that the present invention is not limited to the exact construction described above and illustrated in the drawings, and various modifications and changes can be made without departing from the scope thereof, which is limited only by the appended claims.

Claims (8)

A piezoelectric micromotor including a stator and a rotor, wherein the stator includes a control deformation portion, a passive deformation portion, and a group of transmission links;
At least one rotor through-hole is provided in the controlled deformation portion and the passive deformation portion, and the rotor is provided in the rotor through-hole;
The control deformation unit is further provided with an inverse piezoelectric unit for generating deformation,
the power transmission link group is located between the control deformation section and the passive deformation section, the power transmission link group includes at least two power transmission links, both ends of the power transmission links are connected to the control deformation section and the passive deformation section, respectively;
the control deformation portion, the passive deformation portion, and the power transmission link group are integrally formed,
the control deformation section includes a first control deformation section and a second control deformation section, the power transmission link group includes a first link group and a second link group, the first link group is located between the first control deformation section and the passive deformation section, the second link group is located between the second control deformation section and the passive deformation section, and the first control deformation section and the second control deformation section are installed symmetrically on both sides of the passive deformation section,
A piezoelectric micromotor characterized in that the first control deformation portion and the second control deformation portion are rectangular, the inverse piezoelectric portion is located on each of the four sides of the first control deformation portion and the second control deformation portion, and the four corners of the first control deformation portion and the second control deformation portion are arc-shaped . 2. The piezoelectric micromotor of claim 1, wherein the inverse piezoelectric sections are adapted to generate deformations upon receiving excitation signals, the two opposing inverse piezoelectric sections in each of the control deformation sections are a pair, the two pairs of inverse piezoelectric sections in each of the control deformation sections are adapted to receive cosine excitation signals and sine excitation signals, respectively, and the frequencies of the excitation signals are within the resonant excitation range of the control deformation sections. 3. The piezoelectric micro-motor of claim 2 , wherein the resonant excitation range of the control deformation portion is 393.368 kHz to 393.871 kHz. The direction of the control deformation portion directed toward the passive deformation portion is a horizontal direction, and the direction perpendicular to the horizontal direction is a vertical direction;
the inverse piezoelectric portion located in the first control deformation portion includes a first set and a second set, the first set being located on a horizontal side of the first control deformation portion and the second set being located on a vertical side of the first control deformation portion; the inverse piezoelectric portion located in the second control deformation portion includes a third set and a fourth set, the third set being located on a horizontal side of the second control deformation portion and the fourth set being located on a vertical side of the second control deformation portion;
3. The piezoelectric micromotor of claim 2, wherein the first and fourth sets are used to receive sinusoidal excitation signals and the second and third sets are used to receive cosine excitation signals, or the first and fourth sets are used to receive cosine excitation signals and the second and third sets are used to receive sinusoidal excitation signals. The piezoelectric micromotor further includes microteeth;
the microteeth are installed in the rotor through-hole and positioned between the stator and the rotor, the microteeth are installed on at least one of the stator and the rotor, and the stator contacts the rotor via the microteeth;
the microteeth are equally spaced and the spacing between adjacent microteeth is an integer multiple of a wavelength, the wavelength being in accordance with the formula λ=v×T, where λ is the wavelength, v is the speed of sound in the stator or rotor, and T is the period during which a sinusoidal excitation signal is applied;
The piezoelectric micromotor further includes a micro-drive structure;
The piezoelectric micro motor of claim 1, characterized in that the micro-drive structure includes conductive posts and a micro-drive circuit, the micro-drive circuit is mounted on a flexible carrier board, one end of the conductive posts is electrically connected to the micro-drive circuit, and the other end is electrically connected to the inverse piezoelectric portion. To provide a base and
laser cutting the base to form a stator base, and plating a 0.01 mm to 0.1 mm thick inverse piezoelectric portion on the stator base using magnetron sputtering technology;
After forming the inverse piezoelectric portion, polarizing the inverse piezoelectric portion by a polarization process to form a stator;
providing a flexible carrier board after poling the inverse piezoelectric portion;
forming a micro-drive circuit on the flexible carrier board to form a micro-drive structure;
electrically connecting pads of the micro-drive circuit to the counter-piezoelectric portion ;
the stator base includes a first controllable deformation section, a second controllable deformation section, a passive deformation section, a first link group, and a second link group, the first link group being located between the first controllable deformation section and the passive deformation section, the second link group being located between the second controllable deformation section and the passive deformation section, the first controllable deformation section and the second controllable deformation section being symmetrically installed on both sides of the passive deformation section,
the first control deformation portion and the second control deformation portion are rectangular, the inverse piezoelectric portion is located on each of four sides of the first control deformation portion and the second control deformation portion, and four corners of the first control deformation portion and the second control deformation portion are arc-shaped.
A method for manufacturing a piezoelectric micromotor, comprising: The reverse piezoelectric portion is formed on the stator base by plating using a magnetron sputtering technique, and the reverse piezoelectric portion is polarized by a polarization process.
placing a polymer mask plate on the stator base, and plating the inverse piezoelectric portion on the stator base using a magnetron sputtering technique;
7. The method for manufacturing a piezoelectric micro-motor according to claim 6 , further comprising: after forming the inverse piezoelectric portion, removing the polymer mask plate, and poling the inverse piezoelectric portion by a corona poling process. After poling the inverse piezoelectric part by a polarization process,
a polymer mask plate is placed on the stator, and a rotor is formed in the rotor through-hole by plating using a magnetron sputtering technique;
removing the polymer mask plate after forming the rotor;
After forming the rotor,
attaching a preload structure to the stator;
forming a micro driver circuit on a flexible carrier board by inkjet printing;
placing a solid sleeve on a pad of the micro-drive circuit, the hollow portion of the solid sleeve being aligned with the pad of the micro-drive circuit;
pouring a conductive adhesive into the solid sleeve;
removing the solid sleeve after the conductive adhesive has solidified, and grinding the solidified conductive adhesive to form conductive posts;
8. The method for manufacturing a piezoelectric micro-motor according to claim 7 , further comprising: electrically connecting the other end of the conductive post to the inverse piezoelectric portion.