A dual-rotor rotary piezoelectric motor

Abstract

The present invention discloses a dual-rotor rotary piezoelectric motor, belonging to the field of piezoelectric actuators. The motor drives the rotor to perform rotary motion by controlling different deformation modes of the flexible beam, achieving independent control of the speeds and output torques of the two rotors of the motor respectively. In the present invention, piezoelectric ceramics are pasted on the surface of the flexible beam with driving feet to form a piezoelectric stator. Different-phase and different-frequency alternating voltages are applied to multiple piezoelectric ceramics respectively. The inverse piezoelectric effect of the piezoelectric ceramics is utilized to stimulate the stator to generate different deformations, so that the end parts of the driving feet on the surface of the flexible beam generate elliptical motion trajectories to drive the two coaxial rotors to perform rotary motion. Four groups of stators are evenly installed on the base, and the independent control of the rotational speeds and output torques of the two rotors is achieved by using different driving modes of the four groups of stators.

Description

Technical Field

[0001] The present invention belongs to the field of piezoelectric actuators, and particularly relates to a dual-rotor rotary piezoelectric motor. Background Art

[0002] As a new type of motor, the rotary piezoelectric motor has broad application prospects in the fields of car electrical appliances, office automation equipment, precision instruments, computers, industrial control systems, aerospace, intelligent robots, etc. According to the research results of piezoelectric motors, they have been successfully applied in the fields of automatic focusing devices, conveying devices, automatic lifting devices, precision plotters, and micromachined actuators of cameras abroad. At the same time, in some fields, the demand for piezoelectric motors with dual-rotor output is also increasing. Most of the current rotary piezoelectric motors use piezoelectric ceramics pasted on the surface of a rigid stator to excite the inherent vibration modes of the stator, thereby driving the rotor to rotate. Based on this method, it is difficult to drive a dual-rotor piezoelectric stator, or even if the dual-rotor drive is achieved, the individual control of the rotational speeds and torques of the two rotors cannot be realized, thus greatly affecting the application range of the rotary piezoelectric motor. Therefore, the demand for a rotary piezoelectric motor that can achieve individual control of dual rotors is particularly urgent. Summary of the Invention

[0003] The present invention provides a dual-rotor rotary piezoelectric motor. The motor drives the rotor to perform a rotational motion by controlling different deformation modes of a flexible beam, and realizes the independent control of the speeds and output torques of the two rotors of the motor respectively.

[0004] To achieve the above object, the present invention adopts the following technical solutions:

[0005] A dual-rotor rotary piezoelectric motor, the piezoelectric motor is a dual-rotor rotary piezoelectric motor driven by a flexible beam, and includes: a base portion, a stator portion, and a rotating portion; the base portion is a symmetric structure, each stator portion is symmetrically installed on the side of the base portion, and two rotating portions are symmetrically installed on both sides of the base portion.

[0006] In the above structure, the base portion includes a base 3. The base 3 is a square structure. Four square stator mounting grooves 301 are respectively arranged on the four sides of the base 3. One end of the inner side of each stator mounting groove 301 is provided with a slideway 302. The outer end of each slideway 302 is provided with an elastic plug mounting surface 303. Two threaded holes 304 are symmetrically arranged on each elastic plug mounting surface 303. Two hinge support end rotary shaft mounting holes 305 are symmetrically arranged at the opposite end of the inner side slideway 302 of each stator mounting groove 301. Convex platforms 306 are respectively arranged at the central positions of both sides of the base 3.

[0007] The stator part has four groups in total and is respectively installed in four stator installation grooves 301 of the base 3. Each group of the stator part includes two rotating shafts 4, four piezoelectric ceramic sheets 6, a stator base 8, a slider 10, a gasket 11, and an elastic plug 12. The stator base 8 is a symmetric flexible beam structure with thin ends and a thick middle. Driving feet 802 are respectively arranged on both sides of the middle position of the stator base 8. On each side of each driving foot 802 on the stator base 8 is a piezoelectric ceramic sheet mounting surface 801, and the four piezoelectric ceramic sheets 6 are respectively installed on the piezoelectric ceramic sheet mounting surfaces 801; the slider 10 is a "concave" square structure, and a sliding end rotating shaft mounting hole 1001 is arranged inside its concave surface. The concave surface of the slider 10 is installed inward in the slideway 302 of the base 3; a clamping groove 401 is arranged on the side surface of the rotating shaft 4, and a mounting shaft 402 is arranged at the center of the rotating shaft 4. The two ends of the stator base 8 are respectively installed in the clamping grooves 401 of the two rotating shafts 4, one mounting shaft 402 is installed in the hinge support end rotating shaft mounting hole 305 on the base 3, and the other mounting shaft is installed in the sliding end rotating shaft mounting hole 1001 on the slider 10; the elastic plug 12 is a "T" - shaped structure, and a mounting hole 1202 is arranged on its end surface. The convex end of it is composed of an elastic material 1201. The mounting hole 1202 on the elastic plug 12 is connected to the threaded hole 304 on the base 3, and a gasket 11 is installed between the elastic plug 12 and the base 3.

[0008] The rotating part has two groups in total and is symmetrically installed on the convex platform 306 of the base 3. Each group of the rotating part includes a rotor 1, a bearing outer pressure screw 2, a friction plate 5, a bearing inner pressure screw 7, and a bearing 9. The rotor 1 is a circular - ring structure, including: a friction material bonding surface 101, a bearing outer ring mounting surface 102, and an outer pressure screw mounting surface 103. The friction material bonding surface 101 is located on the bottom end surface of the outer ring of the rotor. The bearing outer ring mounting surface 102 is located at the lower end of the inner ring surface of the circular - ring convex platform of the rotor. The outer pressure screw mounting surface 103 is located at the upper end of the inner ring surface of the circular - ring convex platform of the rotor. The friction plate 5 is bonded to the friction material bonding surface 101 of the rotor 1; the inner ring of the bearing 9 is installed on the bearing inner ring mounting surface 308 at the upper end of the convex platform 306, the outer ring of the bearing 9 is installed on the bearing outer ring mounting surface 102 of the rotor 1, the bearing inner pressure screw 7 is installed on the inner pressure screw mounting surface 307 at the lower end of the convex platform 306, and the bearing outer pressure screw 2 is installed on the outer pressure screw mounting surface 103 of the rotor 1. The bearing 9 and the rotor 1 are installed on the base 3 through the bearing inner pressure screw 7 and the bearing outer pressure screw 2.

[0009] Advantages of the present invention: The present invention provides a dual-rotor rotary piezoelectric motor. Multiple piezoelectric ceramics are pasted on the surface of a flexible beam with driving feet. Different deformation modes of the flexible beam are induced by different excitation methods of the multiple piezoelectric ceramics, so as to drive two symmetrical rotors to generate rotary motion. The piezoelectric material itself has the characteristic of fast response. The flexible beam stator structure made of the piezoelectric material in the present invention is applied to the dual-rotor rotary motor, which can achieve fast response, thereby enhancing the controllability of the motor. The two rotating parts are controlled by four groups of stator parts, and the forward and reverse rotation speeds of the two rotors can be independently controlled by changing the excitation sequence of the piezoelectric ceramics. The flexible beam pasted with piezoelectric ceramics is used as the main driving mechanism. The flexible beam itself has the characteristics of light weight and simple structure. The piezoelectric motor made of it has advantages such as small weight and thin thickness. In addition, the motor of the present invention is not sensitive to magnetic fields and does not generate magnetic fields; it has good speed and position control performance and high precision; it has a high control bandwidth; it consumes relatively less power; its external dimensions can be arbitrarily designed according to user requirements; it has the advantages of small vibration, low noise and stable operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 is a schematic structural diagram of the present invention;

[0011] Figure 2 is a schematic diagram of the base of the present invention;

[0012] Figure 3 is a front view of the base of the present invention;

[0013] Figure 4 is a schematic diagram of the stator part of the present invention;

[0014] Figure 5 is a schematic diagram of the rotor of the present invention;

[0015] Figure 6 is a schematic diagram of the deformation of the flexible beam of the present invention;

[0016] Figure 7 is a schematic diagram of the driving principle of the present invention;

[0017] In the figure, 1 is the rotor, 2 is the external pressure screw of the bearing, 3 is the base, 4 is the rotating shaft, 5 is the friction plate, 6 is the piezoelectric ceramic sheet, 7 is the internal pressure screw of the bearing, 8 is the stator seat, 9 is the bearing, 10 is the slider, 11 is the gasket, 12 is the elastic plug, 101 is the bonding surface of the friction material, 102 is the mounting surface of the outer ring of the bearing, 103 is the mounting surface of the external pressure screw, 301 is the stator mounting groove, 302 is the slideway, 303 is the mounting surface of the elastic plug, 304 is the threaded hole, 305 is the mounting hole for the rotating shaft of the hinge support end, 306 is the convex platform, 307 is the mounting surface of the internal pressure screw, 308 is the mounting surface of the inner ring of the bearing, 401 is the clamping groove, 402 is the mounting shaft, 601 is the piezoelectric ceramic sheet a, 602 is the piezoelectric ceramic sheet b, 603 is the piezoelectric ceramic sheet c, 604 is the piezoelectric ceramic sheet d, 801 is the mounting surface of the piezoelectric ceramic sheet, 802 is the driving foot, 1001 is the mounting hole for the rotating shaft of the sliding end, 1201 is the elastic material, 1202 is the mounting hole. Detailed implementation mode

[0018] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments:

[0019] As Figure 1 shown, a dual-rotor rotary piezoelectric motor, the piezoelectric motor is a dual-rotor rotary piezoelectric motor driven by a flexible beam, specifically including: a base part, a stator part and a rotating part; as Figure 2 and Figure 3 shown, the base part includes a base 3, the base 3 is a square structure, including four stator mounting grooves 301, four slideways 302, four mounting surfaces 303 of elastic plugs, eight threaded holes 304, eight mounting holes 305 for the rotating shaft of the hinge support end, two convex platforms 306, two mounting surfaces 307 of internal pressure screws, two mounting surfaces 308 of the inner ring of the bearing, the four stator mounting grooves 301 are square groove structures and are evenly distributed on the base 3, the four slideways 302 are evenly distributed on the base and are located inside the stator mounting grooves 301, the four mounting surfaces 303 of elastic plugs are evenly distributed on the base and are respectively located at the ends of the four slideways 302, the eight threaded holes 304 are arranged in pairs on the mounting surfaces 303 of elastic plugs, the eight rotating shaft mounting holes 305 are arranged in pairs inside the four stator mounting grooves 301, the two convex platforms 306 are symmetrically arranged on the base, the two mounting surfaces 307 of internal pressure screws are symmetrically distributed and are respectively located at the ends of the two convex platforms, and the two bearing mounting surfaces 308 are symmetrically distributed and are respectively located in the middle of the two convex platforms.

[0020] As Figure 4As shown in the figure, there are a total of four groups of stator parts, which are respectively installed in the four stator installation grooves 301 of the base 3. Each group of stator parts includes two rotating shafts 4, four piezoelectric ceramic sheets 6, a stator base 8, a slider 10, a gasket 11, and an elastic plug 12. The stator base 8 is a symmetric flexible beam structure with thin ends and a thick middle, including four piezoelectric ceramic sheet mounting surfaces 801 and two driving feet 802. The four piezoelectric ceramic sheets 6 are respectively pasted on the four piezoelectric ceramic sheet mounting surfaces 801 of the stator base 8. The slider 10 is a "concave" square structure, and a sliding end rotating shaft mounting hole 1001 is arranged in its concave surface. The concave surface of the slider 10 is installed inward in the slideway 302 of the base 3. A clamping groove 401 and a mounting shaft 402 are arranged on the rotating shaft 4. The two ends of the stator base 8 are respectively installed in the clamping grooves 401 of the two rotating shafts 4. The mounting shaft 402 on one rotating shaft 4 is installed in the hinge support end rotating shaft mounting hole 305 on the base 3, and the other rotating shaft is installed in the sliding end rotating shaft mounting hole 1001 on the slider 10. The elastic plug 12 is a "T" - shaped structure, the convex end of which is composed of an elastic material 1201, and a mounting hole 1202 is arranged on its end surface. The mounting hole 1202 on the elastic plug 12 is connected to the threaded hole 304 on the base 3 by using a screw, and a gasket 11 is installed between the elastic plug 12 and the base 3.

[0021] As Figure 5 shown, there are a total of two groups of rotating parts, which are symmetrically installed on the convex platform 306 of the base 3. Each group of rotating parts includes a rotor 1, a bearing outer pressure screw 2, a friction plate 5, a bearing inner pressure screw 7, and a bearing 9. The rotor 1 is a circular ring structure and includes: a friction material pasting surface 101, a bearing outer ring mounting surface 102, and an outer pressure screw mounting surface 103. The friction plate 5 is pasted on the friction material pasting surface 101 of the rotor 1. The inner ring of the bearing is installed on the bearing inner ring mounting surface 308 of the base 3, the outer ring is installed on the bearing outer ring mounting surface 102 of the rotor 1, the bearing inner pressure screw 7 is installed on the inner pressure screw mounting surface 307 of the base 3, and the bearing outer pressure screw 2 is installed on the outer pressure screw mounting surface 103 of the rotor 1. The bearing 9 and the rotor 1 are installed on the base 3 through the bearing inner pressure screw 7 and the bearing outer pressure screw 2.

[0022] Taking one group of stator parts as an example, combined with Figure 6 and 7 to illustrate the driving method. Four piezoelectric ceramics are pasted on the surface of each flexible beam, and the polarization directions of each ceramic are the same. In the initial state, the installation method of the piezoelectric ceramics in the flexible beam is as Figure 6As shown in Fig. a, different voltages are applied to the piezoelectric ceramics respectively to cause different deformations of the flexible beam. In one driving cycle, in the first stage, the ceramic sheet 601 elongates, 602 shortens, 603 and 604 do not deform, the friction material bonding surface 101 is located on the bottom end face of the outer ring of the rotor, the bearing outer ring mounting surface 102 is located at the lower end of the inner ring surface of the rotor annular boss, and the external pressure screw mounting surface 103 is located at the upper end of the inner ring surface of the rotor annular boss. At this time, the deformation of the flexible beam is as shown in Figure 6 Fig. b; in the second stage, 603 and 604 are energized to make 603 elongate and 604 shorten. The deformation mode of the flexible beam is as shown in Figure 6 Fig. c; in the third stage, the voltages applied to the ceramic sheets 601 and 602 are cancelled, and the deformation mode of the flexible beam is as shown in Figure 6 Fig. d; in the fourth stage, the voltages applied to the ceramic sheets 603 and 604 are cancelled, and the flexible beam returns to the initial state, as shown in Figure 6 Fig. a; in one driving cycle, the movement trajectory of the end of the driving foot 802 on the flexible beam is elliptical. The elliptical trajectory is used to generate a frictional driving force on the friction material 5 pasted on the surface of the rotor 1, thereby driving the rotor 1 to rotate. When the piezoelectric ceramics are excited in the exactly opposite manner to the above, the driving foot 802 at the lower part of the flexible beam will drive the rotor 1 at the lower end to achieve rotational motion; by changing the frequency and amplitude of the excitation voltage, the deformation speed and output force of the flexible beam are controlled, so as to realize the independent control of the rotational speeds and torques of the two rotors 1; by installing a slider 10 and an elastic plug 12 at the sliding end of the flexible beam, a certain pre-pressure is provided for the flexible beam as shown in Figure 4 , so that the flexible beam can output sufficient force and displacement when deforming, and further increase the electromechanical coupling efficiency of the motor.

[0023] The above are only the preferred embodiments of the present invention, which will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements made all fall within the protection scope of the present invention.

Claims

1. A dual-rotor rotary piezoelectric motor, characterized in that, The piezoelectric motor is a double-rotor rotary piezoelectric motor driven by a flexible beam, comprising: a base portion, a stator portion, and a rotating portion; the base portion has a symmetric structure, and each group of stator portions is symmetrically installed on the sides of the base portion respectively, and two rotating portions are symmetrically installed on both sides of the base portion; there are four groups of the stator portions in total and they are respectively installed in four stator installation grooves (301) of the base (3); each group of the stator portions includes two rotating shafts (4), four piezoelectric ceramic sheets (6), a stator base (8), a slider (10), a gasket (11), and an elastic plug (12). The stator base (8) is a symmetric flexible beam structure with thin ends and a thick middle. On both sides of the middle position of the stator base (8), driving feet (802) are respectively arranged. On each side of each driving foot (802) on the stator base (8), there is a piezoelectric ceramic sheet mounting surface (801), and the four piezoelectric ceramic sheets (6) are respectively installed on the piezoelectric ceramic sheet mounting surfaces (801); the slider (10) is a "concave"-shaped square structure, and a sliding-end rotating shaft mounting hole (1001) is arranged inside its concave surface. The concave surface of the slider (10) is installed inward in the slideway (302) of the base (3); a clamping groove (401) is arranged on the side surface of the rotating shaft (4), and a mounting shaft (402) is arranged at the center of the rotating shaft (4). The two ends of the stator base (8) are respectively installed in the clamping grooves (401) of the two rotating shafts (4), and one mounting shaft (402) is installed in the hinge-end rotating shaft mounting hole (305) on the base (3), and the other mounting shaft is installed in the sliding-end rotating shaft mounting hole (1001) on the slider (10); the elastic plug (12) is a "T"-shaped structure, and a mounting hole (1202) is arranged on its end surface, and its convex-end portion is composed of an elastic material (1201). The mounting hole (1202) on the elastic plug (12) is connected to the threaded hole (304) on the base (3), and a gasket (11) is installed between the elastic plug (12) and the base (3); there are two groups of the rotating portions in total and they are symmetrically installed on the convex platforms (306) of the base (3). Each group of the rotating portions includes a rotor (1), a bearing outer pressure screw (2), a friction plate (5), a bearing inner pressure screw (7), and a bearing (9). The rotor (1) is a circular ring structure, including: a friction material bonding surface (101), a bearing outer ring mounting surface (102), and an outer pressure screw mounting surface (103). The friction material bonding surface (101) is located on the bottom end surface of the outer ring of the rotor, the bearing outer ring mounting surface (102) is located at the lower end of the inner ring surface of the circular convex platform of the rotor, and the outer pressure screw mounting surface (103) is located at the upper end of the inner ring surface of the circular convex platform of the rotor. The friction plate (5) is bonded to the friction material bonding surface (101) of the rotor (1);The inner ring of the bearing (9) is installed on the bearing inner ring mounting surface (308) at the upper end of the boss (306), the outer ring of the bearing (9) is installed on the bearing outer ring mounting surface (102) on the rotor (1), the inner bearing pressure screw (7) is installed on the inner pressure screw mounting surface (307) at the lower end of the boss (306), and the outer bearing pressure screw (2) is installed on the outer pressure screw mounting surface (103) of the rotor (1). The bearing (9) and the rotor (1) are installed on the base (3) by the inner bearing pressure screw (7) and the outer bearing pressure screw (2).; 2. The dual-rotor rotary piezoelectric motor according to claim 1, characterized in that, The described base portion includes a base (3). The base (3) has a square structure. Four square stator mounting grooves (301) are respectively arranged on the four side edges of the base (3). A slideway (302) is arranged at one end inside each stator mounting groove (301). An elastic plug mounting surface (303) is arranged at the outer end of each slideway (302). Two threaded holes (304) are symmetrically arranged on each elastic plug mounting surface (303). Two hinge support end rotation shaft mounting holes (305) are symmetrically arranged at the opposite end of the slideway (302) inside each stator mounting groove (301). Protrusions (306) are respectively arranged at the central positions of the two surfaces of the base (3).

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