Thread pair piezoelectric motor

Abstract

The invention discloses a thread pair piezoelectric motor, and relates to the technical field of piezoelectric motors. The motor comprises a stator, a rotating part and an output shaft, the stator is in threaded connection with the output shaft through the threaded hole; the stator is provided with a plurality of first sinking grooves and a plurality of second sinking grooves which are uniformly distributed along the circumference of the threaded hole, and piezoelectric stacks are mounted in the second sinking grooves; the rotating part is provided with a threaded through hole matched with the output shaft and connected with a connecting column and a fixing column. The connecting column is connected with the side face of the first sinking groove through a flexible hinge. The fixed column is connected with the piezoelectric stack, and the output shaft can axially move by applying a sawtooth wave excitation signal to the piezoelectric stack and utilizing the rotation of the rotating part. According to the piezoelectric motor, the flexible hinge for connecting the stator and the rotating part and the piezoelectric stack are arranged in the first sinking groove and the second sinking groove respectively, the sawtooth wave excitation signal is applied to the piezoelectric stack, the rotating part rotates, axial movement of the output shaft is achieved, and the problems that an existing piezoelectric motor is large in size and complex in control are solved.

Description

Technical Field

[0001] The invention belongs to the technical field of piezoelectric motors, and in particular relates to a threaded pair piezoelectric motor. Background Art

[0002] Piezoelectric motor is a kind of micro-motor, which uses the inverse piezoelectric effect of piezoelectric materials to stimulate the micro-vibration of the stator, and converts the vibration into the rotational (linear) motion of the rotor (motor) through the friction between the stator and the rotor. At present, the commonly used miniaturized structures of piezoelectric motors are rod-type and disc-type, among which the mechanical output performance of rod-type piezoelectric motors is stronger than that of disc-type.

[0003] For example, Chinese patent CN103929090B discloses a cylindrical rotating linear ultrasonic motor excited by a piezoelectric driver and its excitation method. The ultrasonic motor operates in a resonant state and is excited by an alternating current signal with a phase difference of 90° to excite the bending mode of the nut and generate driving force through a thread pair transmission.

[0004] However, the overall structure of the piezoelectric motor in the above-mentioned prior art is relatively large, and the control process and control method are relatively complicated, which affects the convenience of use and control. Summary of the invention

[0005] The object of the present invention is to provide a threaded pair piezoelectric motor, which solves the problems of large size and complex control of existing piezoelectric motors by placing a flexible hinge and a piezoelectric stack that interconnect the stator and the rotating part in a first groove and a second groove respectively, and applying a sawtooth wave excitation signal to the piezoelectric stack and utilizing the rotation of the rotating part to achieve axial movement of the output shaft.

[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 threaded pair piezoelectric motor, comprising a stator, a rotating part and an output shaft; wherein the stator is provided with a threaded hole and is threadedly connected to the output shaft through the threaded hole; the stator is provided with a plurality of first recessed grooves and a plurality of second recessed grooves evenly distributed along the circumference of the threaded hole, and a piezoelectric stack is installed in the second recessed groove; the rotating part has a threaded through hole matched with the output shaft, and the rotating part is fixedly connected with a connecting column corresponding to the first recessed groove, and a fixing column corresponding to the position of the second recessed groove; a flexible hinge is provided on the side of the connecting column, and is connected to the side of the first recessed groove through the flexible hinge; one side of the fixing column is connected to the piezoelectric stack, and the axial movement of the output shaft is realized by applying a sawtooth wave excitation signal to the piezoelectric stack and rotating the rotating part.

[0008] As a preferred technical solution of the present invention, the rotating part is provided with a through slot connected to the threaded through hole, and connecting blocks are symmetrically arranged relative to the through slot, and the two connecting blocks are connected by screws, which are used to adjust the width of the through slot by screws to adjust the tightness of the fit between the threaded through hole and the output shaft.

[0009] As a preferred technical solution of the present invention, flexible hinges are provided on both sides of the connecting column, and the two flexible hinges are respectively connected to the inner side surfaces of the two ends of the first sink.

[0010] As a preferred technical solution of the present invention, both ends of the first sink are provided with mounting grooves, and the flexible hinge is connected with a mounting block matched with the mounting grooves.

[0011] As a preferred technical solution of the present invention, the mounting groove is a T-slot structure.

[0012] As a preferred technical solution of the present invention, the side wall of the installation groove is provided with a screw hole, and the screw hole is matched with a set screw for fixing the installation block by the set screw.

[0013] As a preferred technical solution of the present invention, the flexible hinge is in a diamond-shaped structure or an elliptical structure.

[0014] As a preferred technical solution of the present invention, the present invention further includes a shell, and the shell is fixedly connected to the stator, one end of the shell is fixedly connected to a mounting plate, and the rotating part is located in an internal cavity enclosed by the shell and the mounting plate.

[0015] As a preferred technical solution of the present invention, the stator is a stepped shaft structure.

[0016] As a preferred technical solution of the present invention, the stator is provided with an external thread and matched with a nut, so as to realize installation and fixation of the housing through the nut.

[0017] The present invention has the following beneficial effects:

[0018] The present invention effectively reduces the overall volume by placing the flexible hinge and the piezoelectric stack that connect the stator and the rotating part in the first sink groove and the second sink groove respectively. In addition, by applying a sawtooth wave excitation signal to the piezoelectric stack, the rotating part is pushed to rotate by the pressure top stack, and the output shaft is driven by the rotating part to achieve axial movement of the output shaft. The overall control method is simpler, which is conducive to improving the convenience of overall use.

[0019] 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

[0020] 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.

[0021] Figure 1 It is a structural schematic diagram of a threaded pair piezoelectric motor of the present invention;

[0022] Figure 2 for Figure 1 Schematic diagram of the structure from an upward perspective;

[0023] Figure 3 for Figure 1 A front view of

[0024] Figure 4 for Figure 3 Sectional view at AA in the middle;

[0025] Figure 5 It is a schematic diagram of the structure of the stator and the rotating part;

[0026] Figure 6 for Figure 5 A front view of

[0027] Figure 7 is a schematic diagram of the structure of the stator;

[0028] Figure 8 It is a structural schematic diagram of the rotating part;

[0029] Fig. 9 for Figure 8 A magnified view of the structure of the middle B section;

[0030] Fig.10 It is a motion diagram of the rotating part and the output shaft;

[0031] Fig.11 It is a sawtooth wave waveform diagram;

[0032] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0033] 1-stator, 2-rotating part, 3-output shaft, 4-piezoelectric stack, 5-housing, 6-nut, 101-threaded hole, 102-first recessed groove, 103-second recessed groove, 104-mounting groove, 105-screw hole, 201-threaded through hole, 202-connecting column, 203-fixing column, 204-flexible hinge, 205-through slot, 206-connecting block, 207-mounting block, 501-mounting plate. DETAILED DESCRIPTION

[0034] 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.

[0035] 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.

[0036] Embodiment 1

[0037] See also Figure 1 and 3 As shown, the present invention is a threaded pair piezoelectric motor, comprising a stator 1, a rotating part 2 and an output shaft 3, wherein the stator 1 is a stepped shaft structure, the rotating part 2 is a cylindrical structure, and the output shaft 3 is a screw structure.

[0038] Among them, Figure 5 and 7 As shown, the stator 1 is provided with a threaded hole 101, and is threadedly connected to the output shaft 3 through the threaded hole 101. The end surface of the stator 1 is provided with four first recessed grooves 102 and two second recessed grooves 103 evenly distributed along the circumference of the threaded hole 101, and the length directions of the first recessed grooves 102 and the second recessed grooves 103 are arranged parallel to the tangent direction of the threaded hole 101. The inner side wall of one end of the second recessed groove 103 is connected to a fixed block through a flexible structure, such as a flexible hinge, and the piezoelectric stack 4 is installed through the fixed block.

[0039] like Figure 8 and 9 As shown, the rotating part 2 has a threaded through hole 201 that matches the output shaft 3 , and the rotating part 2 is fixedly connected with a connecting column 202 corresponding to the first sink groove 102 , and a fixing column 203 corresponding to the position of the second sink groove 103 .

[0040] A flexible hinge 204 is provided on the side of the connecting column 202, and it is connected to the side of the first sink 102 through the flexible hinge 204; one side of the fixed column 203 is connected to the piezoelectric stack 4, and the fixed column 203 is also connected to the other end of the piezoelectric stack 4 through a flexible structure, such as a flexible hinge connected to another fixed block.

[0041] Specifically, Figure 6 , 7As shown in FIG. 9 , flexible hinges 204 are provided on both sides of the connecting column 202, and the two flexible hinges 204 are respectively connected to the inner side surfaces of both ends of the first sink 102. Both ends of the first sink 102 are provided with mounting grooves 104, and the mounting grooves 104 are T-shaped groove structures. In addition, the flexible hinges 204 are connected to mounting blocks 207 that match the mounting grooves 104, and the mounting blocks 207 are T-shaped block structures.

[0042] The side wall of the mounting groove 104 is provided with a screw hole 105, and the screw hole 105 is matched with a set screw for fixing the mounting block 207 by the set screw. During installation, the mounting block 207 is inserted into the mounting groove 104 and then tightened by the set screw, so that the mounting block 207 is fixed, thereby realizing the installation of the rotating part 2, and a gap is left between the rotating part 2 and the stator 1.

[0043] like Fig.10 and 11 As shown, by applying a sawtooth wave excitation signal to the piezoelectric stack 4, the two piezoelectric stacks 4 simultaneously push the rotating part 2 to rotate and rotate a certain angle. When the rotating part 2 rotates, it drives the driving shaft 3 to rotate synchronously. By adopting a threaded connection, the driving shaft 3 rotates to achieve axial movement, as shown in the direction of the arrow in the figure.

[0044] As shown by the dotted arrow in the figure, when the piezoelectric stack 4 shrinks and resets rapidly, it drives the rotating part 2 to rotate in the opposite direction and reset. At this time, the driving shaft 3 does not rotate or rotates a small angle due to inertia, thereby completing one control of the driving shaft 3. The overall control method is simpler, which is conducive to improving the overall convenience of use.

[0045] Embodiment 2

[0046] Based on the first embodiment, Figure 5 and 8 As shown, the rotating part 2 is provided with a through slot 205 connected to the threaded through hole 201, and a connecting block 206 is symmetrically arranged relative to the through slot 205. The connecting block 206 and the rotating part 2 are an integral structure, and the two connecting blocks 206 are connected by screws, which are used to adjust the width of the through slot 205 by screwing the screws to adjust the size of the threaded through hole 201, thereby adjusting the tightness of the fit between the threaded through hole 201 and the output shaft 3, so that the rotating part 2 can better drive the output shaft 3 to rotate.

[0047] At the same time, if Fig. 9 As shown, the flexible hinge 204 is in a diamond structure or an elliptical structure. The elliptical structure shown in the figure enables the flexible hinge 204 to achieve compression and stretching effects, and arc grooves can be started at the four quadrant points of the inner wall of the elliptical flexible hinge 204, so that the flexible hinge 204 can be more easily compressed and stretched.

[0048] Embodiment 3

[0049] On the basis of Example 1 or Example 2, Figures 2 to 4 As shown, it also includes a housing 5, and the housing 5 is connected and fixed to the stator 1. Specifically, the stator 1 is provided with an external thread and matched with a nut 6. The housing 5 has a through hole that is gap-matched with the threaded section. The housing 5 is sleeved on the outside of the stator 1, and is used to tighten the nut 6 and use the nut 6 and the shaft shoulder of the stator 1 to support the end wall of the housing 5, thereby realizing the installation and fixation of the housing 5.

[0050] Furthermore, one end of the housing 5 is connected to a mounting plate 501 by screws, and the rotating part 2 is located in the inner cavity enclosed by the housing 5 and the mounting plate 501. The mounting plate 501 has a through hole with an inner diameter larger than the diameter of the drive shaft 3, so that the drive shaft 3 can pass through the mounting plate 501.

[0051] The rotating part 2 and the piezoelectric stack 4 are protected by the mounting plate 501 and the housing 5. At the same time, the whole can be mounted and fixed by the mounting plate 501, which improves the convenience of installation.

[0052] 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.

[0053] 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 threaded pair piezoelectric motor, characterized in that: It comprises a stator (1), a rotating part (2) and an output shaft (3); The stator (1) is provided with a threaded hole (101) and is threadedly connected to the output shaft (3) through the threaded hole (101); the stator (1) is provided with a plurality of first recessed grooves (102) and a plurality of second recessed grooves (103) uniformly distributed along the circumference of the threaded hole (101), and a piezoelectric stack (4) is installed in the second recessed groove (103); The rotating part (2) has a threaded through hole (201) matched with the output shaft (3), and the rotating part (2) is fixedly connected with a connecting column (202) corresponding to the first sink groove (102) and a fixing column (203) corresponding to the position of the second sink groove (103); The side of the connecting column (202) is provided with a flexible hinge (204), and is connected to the side of the first sink groove (102) through the flexible hinge (204); one side of the fixed column (203) is connected to the piezoelectric stack (4), and the axial movement of the output shaft (3) is achieved by applying a sawtooth wave excitation signal to the piezoelectric stack (4) and utilizing the rotation of the rotating part (2).

2. A threaded pair piezoelectric motor according to claim 1, characterized in that: The rotating part (2) is provided with a through slot (205) communicating with the threaded through hole (201), and a connecting block (206) is symmetrically arranged relative to the through slot (205), and the two connecting blocks (206) are connected by screws, and are used to adjust the width of the through slot (205) by means of the screws, so as to adjust the tightness of the fit between the threaded through hole (201) and the output shaft (3).

3. The threaded pair piezoelectric motor according to claim 1, characterized in that: Flexible hinges (204) are provided on both sides of the connecting column (202), and the two flexible hinges (204) are respectively connected to the inner side surfaces at both ends of the first sink (102).

4. A threaded pair piezoelectric motor according to claim 3, characterized in that: Both ends of the first sink (102) are provided with mounting grooves (104), and the flexible hinge (204) is connected to a mounting block (207) matched with the mounting groove (104).

5. A threaded pair piezoelectric motor according to claim 4, characterized in that: The installation groove (104) is a T-shaped groove structure.

6. A threaded pair piezoelectric motor according to claim 4 or 5, characterized in that: The side wall of the installation groove (104) is provided with a screw hole (105), and the screw hole (105) is matched with a set screw for fixing the installation block (207) by means of the set screw.

7. A threaded pair piezoelectric motor according to claim 1, 4 or 5, characterized in that: The flexible hinge (204) is in a diamond-shaped structure or an elliptical structure.

8. The threaded pair piezoelectric motor according to claim 1, characterized in that: It also comprises a shell (5), and the shell (5) is fixedly connected to the stator (1), one end of the shell (5) is fixedly connected to a mounting plate (501), and the rotating part (2) is located in an internal cavity enclosed by the shell (5) and the mounting plate (501).

9. A threaded pair piezoelectric motor according to claim 8, characterized in that: The stator (1) is in a stepped shaft structure.

10. The threaded pair piezoelectric motor according to claim 9, characterized in that: The stator (1) is provided with an external thread and is matched with a nut (6) for installing and fixing the housing (5) through the nut (6).

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