CN120301239A - Motor stator and piezoelectric motor - Google Patents

Abstract

The present application relates to the technical field of piezoelectric motors, and in particular to a motor stator and a piezoelectric motor. The motor stator includes a housing, a base assembly and an actuating assembly. The housing is provided with an active cavity; the base assembly can be movably connected to the cavity wall of the active cavity; the actuating assembly is connected to the base assembly, and the actuating assembly is used to drive the base assembly to move relative to the housing in a first direction, and the first direction intersects with the thickness direction of the actuating assembly. The movable connection of the base assembly can change the overall resonance frequency of the motor stator by adjusting the stiffness so that it matches the operating frequency of the actuating assembly, thereby maximizing the energy transfer efficiency. Therefore, by adding a base assembly, energy can be efficiently transferred, energy loss can be reduced, and the operating efficiency of the piezoelectric motor can be improved.

Description

Motor stator and piezoelectric motor

Technical Field

The application relates to the technical field of piezoelectric motors, in particular to a motor stator and a piezoelectric motor.

Background

The energy generated by deformation of a piezoelectric ultrasonic actuator of the conventional piezoelectric motor is difficult to transfer efficiently, so that the energy loss is high, and the operation efficiency of the piezoelectric motor is reduced.

The information disclosed in this background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person of ordinary skill in the art.

Disclosure of Invention

Based on the above, it is necessary to provide a motor stator and a piezoelectric motor for solving the problems that the energy generated by deformation of a piezoelectric ultrasonic actuator of the conventional piezoelectric motor is difficult to transfer efficiently, so that the energy loss is high and the operation efficiency of the piezoelectric motor is reduced.

In a first aspect, an electric machine stator comprises:

a housing provided with a movable cavity;

the base component can be movably connected with the cavity wall of the movable cavity;

The actuating assembly is connected with the base assembly and used for driving the base assembly to move along a first direction relative to the shell, and the first direction is intersected with the thickness direction of the actuating assembly.

In one embodiment, the base assembly comprises a base body and a rolling body, the actuating assembly is connected to the base body, the rolling body is rotatably connected to the base body, a sliding groove is formed in a cavity wall of the movable cavity, and the rolling body is slidably arranged in the sliding groove.

In one embodiment, the base assembly further comprises a first elastic member, the rolling bodies comprise a first rolling body and a second rolling body, the base body comprises a first side face and a second side face which are oppositely arranged along a second direction, the first rolling body is rotatably connected with the first side face, the first elastic member is connected with the second side face along two ends of the first direction, the second rolling body is rotatably connected with the first elastic member, the second direction is intersected with the first direction and the thickness direction of the actuating assembly in two pairs, and the first direction, the second direction, the thickness direction and the thickness direction of the actuating assembly are not coplanar.

In one embodiment, the motor stator further includes a second elastic member, the second elastic member is located in the movable cavity, and two ends of the second elastic member along the first direction are respectively connected to the outer wall of the base assembly and the cavity wall of the movable cavity.

In one embodiment, the actuating assembly includes a piezoelectric ultrasonic actuator coupled to the base assembly and an output drive foot coupled to an end of the piezoelectric ultrasonic actuator in the first direction, the piezoelectric ultrasonic actuator configured to drive the base assembly in the first direction to move the output drive foot relative to the housing.

In one embodiment, the base assembly and the actuating assembly each comprise two, the actuating assemblies are respectively connected with one base assembly, and the two base assemblies are stacked and arranged at intervals along the thickness direction of the actuating assembly.

In a second aspect, a piezoelectric motor includes a motor stator and a motor mover, the motor stator being drivingly connected to the motor mover in a first direction, the motor stator being the motor stator of the first aspect.

In one embodiment, the piezoelectric motor further includes a friction member connected to the motor mover and disposed between the motor stator and the motor mover along the first direction.

In one embodiment, the piezoelectric motor further comprises a motor base, the motor rotor is arranged on the motor base, and the motor stator is movably connected to the motor base along the first direction.

In one embodiment, the motor base is concavely provided with a movable groove along the first direction, the motor rotor is located outside the movable groove, the piezoelectric motor further comprises a sliding component and a positioning fastener, the sliding component is arranged in the movable groove, the sliding component is connected to the bottom wall of the movable groove, the motor stator is connected to the sliding component, one end of the positioning fastener along the first direction is connected to the side wall of the movable groove, the other end of the positioning fastener is abutted to the motor stator, and the positioning fastener is used for adjusting the position of the motor stator along the first direction.

The actuating component of the motor stator converts electric energy into mechanical vibration through inverse piezoelectric effect, but when the actuating component is directly fixed on the shell, vibration energy can be scattered or reflected due to interface impedance mismatch (such as energy cannot be effectively transmitted due to the fact that the shell is too rigid). The base component is used as a middle flexible connection structure, mechanical impedance of the actuating component and the shell is matched through movable connection, so that vibration energy is more efficiently transferred to the shell or load, and pretightening force between the actuating component and the shell can be adjusted by the base component, and dissipation of energy in a transfer process is reduced. The articulation of the base assembly may reduce rigid friction between the actuation assembly and the housing, further reducing friction losses. The movable degree of freedom of the base assembly can restrict the vibration direction, inhibit irrelevant vibration modes, enable energy to be concentrated in an effective driving direction, and avoid energy waste caused by multidirectional vibration. The movable connection of the base assembly can change the integral resonant frequency of the motor stator by adjusting the rigidity, so that the integral resonant frequency is matched with the working frequency of the actuating assembly, and the energy transmission efficiency is maximized. Therefore, the base assembly is additionally arranged, so that energy can be efficiently transmitted, energy loss is reduced, and the running efficiency of the piezoelectric motor is improved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments or the conventional techniques of the present application, the drawings required for the descriptions of the embodiments or the conventional techniques will be briefly described below, and it is apparent that the drawings in the following description are only embodiments of the present application, and other drawings may be obtained from the disclosed drawings without inventive effort to those skilled in the art.

Fig. 1 is a schematic structural diagram of a motor stator according to an embodiment of the present application.

Fig. 2 is a schematic diagram of an internal structure of a motor stator according to an embodiment of the present application.

Fig. 3 is a schematic structural diagram of a base assembly and an actuating assembly according to an embodiment of the present application.

Fig. 4 is a front view of a base assembly and an actuating assembly provided in an embodiment of the present application.

Fig. 5 is a schematic structural diagram of a motor base and a motor stator according to an embodiment of the present application.

Fig. 6 is a schematic structural diagram of an electrode base, a motor stator and a motor rotor according to an embodiment of the present application.

Fig. 7 is a schematic structural diagram of a piezoelectric motor according to an embodiment of the present application.

Fig. 8 (a) is a schematic diagram of the motor stator in the first operating state, fig. 8 (b) is a schematic diagram of the motor stator in the second operating state, fig. 8 (c) is a schematic diagram of the motor stator in the third operating state, and fig. 8 (d) is a schematic diagram of the motor stator in the fourth operating state.

The reference numerals indicate 100, a piezoelectric motor, 10, a motor stator, 1, a housing, 11, a movable cavity, 12, a sliding chute, 2, a base assembly, 21, a base main body, 211, a clamping groove, 212, a first side face, 213, a second side face, 214, a first mounting structure, 2141, a first sub-mounting body, 2142, a second sub-mounting body, 2143, a hollowed-out groove, 215, a resisting body, 22, a rolling body, 221, a first rolling body, 222, a second rolling body, 23, a first elastic piece, 231, a first concave part, 232, a second concave part, 24, a second mounting structure, 25, a second elastic piece, 3, an actuating assembly, 31, a piezoelectric ultrasonic actuator, 32, an output driving foot, 20, a motor rotor, 30, a friction piece, 40, a motor base, 401, a movable groove, 402, a sliding assembly, 4021, a sliding rail, 4022, and a sliding block.

Detailed Description

In order that the above objects, features and advantages of the application will be readily understood, a more particular description of the application will be rendered by reference to the appended drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. The present application may be embodied in many other forms than described herein and similarly modified by those skilled in the art without departing from the spirit of the application, whereby the application is not limited to the specific embodiments disclosed below.

Referring to fig. 1, in a first aspect, an embodiment of the present application provides a motor stator 10. Referring to fig. 2, the motor stator 10 includes a housing 1, a base assembly 2, and an actuating assembly 3. The shell 1 is provided with a movable cavity 11, the base component 2 can be movably connected with the cavity wall of the movable cavity 11, the actuating component 3 is connected with the base component 2, and the actuating component 3 is used for driving the base component 2 to move along a first direction (Y direction shown in fig. 2) relative to the shell 1, and the first direction is intersected with the thickness direction of the actuating component 3. The actuating assembly 3 of the motor stator 10 converts electrical energy into mechanical vibration by inverse piezoelectric effect, but when directly fixed to the housing 1, vibration energy may be scattered or reflected due to interface impedance mismatch (e.g., the housing 1 is too rigid to effectively transfer energy). The base component 2 is used as an intermediate flexible connection structure, and mechanical impedance of the actuating component 3 and the shell 1 is matched through movable connection, so that vibration energy is more efficiently transferred to the shell 1 or load, and meanwhile, the base component 2 can adjust pretightening force between the actuating component 3 and the shell 1, and dissipation of energy in a transfer process is reduced. The movable connection of the base assembly 2 can reduce the rigid friction between the piezoelectric ultrasonic brake assembly and the shell 1, and further reduce friction loss. The motion degree of freedom of the base assembly 2 can restrict the vibration direction, inhibit irrelevant vibration modes, enable energy to be concentrated in an effective driving direction, and avoid energy waste caused by multidirectional vibration. The articulation of the base assembly 2 can be achieved by adjusting the stiffness to change the overall resonant frequency of the motor stator 10 to match the operating frequency of the actuating assembly 3, thereby maximizing the energy transfer efficiency. By adding the base component 2, energy can be efficiently transferred, energy loss is reduced, and the operation efficiency of the piezoelectric motor 100 is improved.

Referring to fig. 1, in an alternative embodiment, the housing 1 is square in shape, and the housing 1 includes a bottom wall, side walls, and a top wall. The side wall is provided between the bottom wall and the top wall in the thickness direction of the housing 1. The bottom wall, side walls and top wall are co-configured to form the movable chamber 11. The side wall is penetrated and is provided with a movable opening communicated with the movable cavity 11, the base component 2 is movably connected to the side wall, and the base component 2 movably penetrates through the movable opening along the first direction.

Referring to fig. 3, in some embodiments, the actuating assembly 3 includes a piezoelectric ultrasonic actuator 31 and an output driving foot 32, the piezoelectric ultrasonic actuator 31 is connected to the base assembly 2, the output driving foot 32 is connected to one end of the piezoelectric ultrasonic actuator 31 along a first direction (Y direction as shown in fig. 3), and the piezoelectric ultrasonic actuator is used to drive the base assembly 2 to move along the first direction so as to move the output driving foot 32 relative to the housing 1.

The piezoelectric ultrasonic actuator 31 provided by the embodiment of the application internally comprises a ceramic layer, an insulating layer, an internal electrode and an external electrode. The ceramic layer is mainly made of lead zirconate titanate, and electric domains are arranged in an oriented mode after polarization. Under the action of the electric field, it will generate mechanical deformation, which is a core component of the piezoelectric ultrasonic actuator 31 for achieving the electromechanical conversion. The insulating layer is positioned between ceramic layers or at the edges, plays a role in electrical insulation, can effectively prevent the short circuit of the internal electrode, and ensures the normal operation of the actuator. The internal electrodes are embedded between the ceramic layers in a cross-lamination manner along the thickness direction of the piezoelectric ultrasonic actuator 31, and a silver-palladium alloy material is used for applying a driving electric field to convert electric energy into mechanical energy. The external electrode is electrically connected to the internal electrode to provide an interface for an external circuit, so that the external electric energy can be smoothly input into the piezoelectric ultrasonic actuator 31 to drive the ceramic layer to generate mechanical deformation.

The electromechanical conversion principle of the motor stator 10 provided in the embodiment of the present application is that the piezoelectric ultrasonic actuator 31 deforms in the length direction (first direction, Y direction as shown in fig. 3) after a voltage is applied to the thickness direction (third direction, Z direction as shown in fig. 3) of the piezoelectric ultrasonic actuator. This is based on the piezoelectric effect of the ceramic layer inside the piezoelectric ultrasonic actuator 31, and when a driving voltage is applied in the thickness direction of the ceramic layer, mechanical deformation of the ceramic layer in the length direction occurs due to a change in the directional arrangement of the electric domains in the ceramic layer under the action of an electric field. The internal electrode is responsible for applying a driving electric field, the external electrode is connected with a driving voltage, and the internal electrode and the external electrode work cooperatively to convert electric energy into mechanical energy of the ceramic layer.

It should be noted that, in the present piezoelectric motor 100 driven by a combination of a piezoelectric ceramic sheet and an elastomer, the motor stator 10 provided in the embodiment of the present application is formed by stacking ceramic layers and internal electrodes in a mutually crossed manner, and the piezoelectric ultrasonic actuator 31 is divided into two symmetrical structures by different polarization partitions. The structure avoids the sticking between the piezoelectric ceramic plate and the elastomer at present, and can directly transfer the energy generated by the deformation of the ceramic layer to the position of the output driving foot 32, thereby reducing the energy loss and increasing the output efficiency.

The output drive foot 32 is made of a silicon nitride material or an aluminum oxide material, and the output drive foot 32 is sintered at the end of the ceramic layer of the piezoelectric ultrasonic actuator 31. The output driving foot 32 can convert mechanical energy generated by deformation of the ceramic layer into directional friction force, so that energy conversion is realized, the electrode mover is driven to move, and meanwhile, under the conditions of high-frequency vibration and continuous contact friction, the output driving foot 32 can ensure the structural integrity of the piezoelectric ultrasonic actuator 31.

In alternative embodiments, the base assembly 2 may be movably coupled to the housing 1 in a sliding or rolling connection, or the like.

Referring to fig. 3, in preferred embodiments, the base assembly 2 includes a base body 21 and rolling bodies 22, the rolling bodies 22 are rotatably connected to the base body 21, the actuating assembly 3 is connected to the base body 21, the cavity wall of the movable cavity 11 is concavely provided with a sliding slot 12 (see fig. 2), and the rolling bodies 22 are slidably disposed in the sliding slot 12. The friction resistance of the rolling bodies 22 is smaller than sliding friction, so that the energy loss between the base assembly 2 and the shell 1 is greatly reduced, the vibration energy of the actuating assembly 3 is more efficiently transmitted to the shell 1, and the mechanical energy caused by friction is prevented from being converted into heat energy to be dissipated. The rolling contact allows the base assembly 2 to respond to high frequency vibrations at a lower actuation threshold, ensuring that micro-deformation of the piezoelectric ceramic can be quickly converted into directional motion, improving drive efficiency. The rolling elements 22 can reduce motion jamming caused by instantaneous static friction in a vibration environment, and ensure continuous and stable operation of the piezoelectric motor 100. The geometric cooperation of the sliding groove 12 and the rolling body 22 forms a one-dimensional kinematic pair, so that the vibration energy of the ceramic layer is concentrated on an effective driving axis, the rigidity characteristic of rolling connection can inhibit a high-order vibration mode, and the energy dispersion caused by parasitic vibration is avoided. The rolling bodies 22 can automatically balance the pretightening force between the piezoelectric assembly and the shell 1 in the sliding groove 12, so that the contact interface is always in a good stress state. Therefore, the base assembly 2 is arranged as the base main body 21 and the rolling bodies 22, so that friction loss can be reduced, energy efficiency can be improved, service life and reliability of the base assembly 2 can be prolonged, vibration direction can be precisely restrained, energy dissipation can be restrained, and dynamic adjustment of pretightening force and matching impedance can be realized.

In alternative embodiments, the rolling elements 22 may be balls or rollers or the like.

Referring to fig. 3, in some embodiments, the rolling elements 22 are disposed on a side surface of the base body 21 along a second direction (X direction shown in fig. 3), the base body 21 is provided with a clamping groove 211 along a first direction (Y direction shown in fig. 3), the clamping groove 211 penetrates the base body 21 along a third direction (Z direction shown in fig. 3), the third direction is a thickness direction of the actuating assembly 3, the third direction intersects with the second direction and the first direction two by two, and the third direction and the first direction are not coplanar, and the actuating assembly 3 is clamped in the clamping groove 211. The base body 21 is provided with the clamping groove 211 penetrating the third direction along the first direction to clamp the actuating assembly 3, so that three-dimensional positioning constraint can be realized on the actuating assembly 3, and vibration direction deviation or energy dissipation caused by assembly deviation is avoided. The rigid clamping of the clamping groove 211 can uniformly distribute the pretightening force between the actuating assembly 3 and the base main body 21, and can prevent microcracks or interfacial peeling of the ceramic layer caused by local stress concentration. Meanwhile, the extended design of the clamping slot 211 along the driving direction (the first direction, such as the Y direction shown in fig. 3) allows the piezoelectric assembly to deform along a designated path when excited, reducing the lateral vibration interference, and enabling energy to be efficiently transferred to the output driving foot 32.

In an alternative embodiment, the blocking groove 211 of the base body 21 is provided with a blocking body 215 protruding toward the inside of the blocking groove 211 along the second direction (X direction shown in fig. 3) along the groove top wall and the groove bottom wall along the third direction (Z direction shown in fig. 3). The abutment 215 is used to limit the actuation assembly 3 in a third direction.

In an alternative embodiment, the resisting bodies 215 include four, and the four resisting bodies 215 are provided at both ends of the base body 21 in the first direction.

In some embodiments, the base assembly 2 further includes a first elastic member 23, the rolling element 22 includes a first rolling element 221 and a first rolling element 222, the base body 21 includes a first side 212 and a second side 213 disposed opposite to each other along a second direction, the first rolling element 221 is rotatably connected to the first side 212, two ends of the first elastic member 23 along the first direction are connected to the second side 213, the first rolling element 222 is rotatably connected to the first elastic member 23, and the second direction intersects with the first direction and the thickness direction of the actuating assembly 3 two by two, and the three are not coplanar. The first elastic piece 23 is additionally arranged and connected with the first rolling body 222, so that the actuating assembly 3 is prevented from excessively moving, and the running stability is ensured. The elastic deformation of the first elastic member 23 can continuously provide a proper pretightening force for the first rolling element 222, so as to ensure that the first rolling element 222 and the chute 12 keep constant contact, and avoid vibration or positioning error caused by the generation of gaps. The first elastic member 23 attenuates high-frequency vibration energy by damping characteristics, reduces the amplitude transmitted to the base body 21, and also damps inertial impact when the direction of movement is abrupt, extending the life of the base assembly 2. The first elastic member 23 allows a slight displacement of the first rolling element 222 in the first direction, and this controllable degree of freedom ensures the accommodation of manufacturing errors, prevents multiaxial coupling vibration by elastic constraint, and improves motion stability.

Referring to fig. 3, in some embodiments, the first side 212 and the second side 213 are each provided with a first mounting structure 214 protruding along the second direction (X direction as shown in fig. 3), the first rolling element 221 is rotatably connected to the first mounting structure 214 on the first side 212, and two ends of the first elastic member 23 along the first direction (Y direction as shown in fig. 3) are respectively connected to the first mounting structure 214 on the second side 213. The protruding first mounting structure 214 provides a rigid positioning reference for the mounting of the first rolling element 221, the first rolling element 222 and the first elastic member 23, ensuring the accurate mounting of the components in a preset direction. The raised first mounting structure 214 enhances contact surface support strength, reduces deflection due to stress deformation, and thereby improves stability of the motion profile. The first elastic piece 23 is connected with the first rolling body 222 through the first mounting structure 214, and can apply controllable pretightening force, so that the rolling body 22 and the contact surface are guaranteed to be tightly attached all the time, and vibration or precision loss caused by gaps is avoided. The flexible deformability of the first elastic member 23 can compensate for minor displacements due to assembly errors or dynamic operation. The protruding first mounting structure 214 serves as a fixed fulcrum, allowing the first elastic member 23 to adaptively deform in the second direction, and maintaining the optimal contact state between the first rolling element 222 and the chute 12. The first rolling bodies 221 are directly mounted on the protruding rigid first mounting structure 214, and the first rolling bodies 222 are connected through the first elastic member 23 to form a rigid+elastic hybrid supporting structure, so that direct friction impact is reduced through the rigid first mounting structure 214, high-frequency vibration is absorbed through the first elastic member 23, and movement smoothness and service life can be improved.

Referring to fig. 3 and 4, in some embodiments, the first mounting structure 214 includes a first sub-mounting body 2141 and a second sub-mounting body 2142 that are disposed at intervals along a first direction, the first rolling body 221 includes two first sub-mounting bodies 2141 and 2142 that are respectively rotatably connected to the first side 212, two ends of the first elastic member 23 along the first direction are respectively connected to the first sub-mounting body 2141 and the second sub-mounting body 2142, a cross-sectional area of the first sub-mounting body 2141 increases gradually along a second direction and a direction pointing to the first sub-mounting body 2142, and a cross-sectional area of the second sub-mounting body 2142 increases first along the second direction and then remains unchanged along the direction pointing to the second sub-mounting body 2142, and a hollow slot 2143 is formed through the second sub-mounting body 2142 along a third direction. The wedge-shaped section (gradually increasing along the second direction) of the first sub-mounting body 2141 can uniformly disperse the stress of the stress area, so that fatigue fracture caused by local stress concentration is avoided, the section of the second sub-mounting body 2142 is increased first and then kept stable, a rigid supporting platform is formed, stress deformation is further restrained, and structural stability is enhanced. The hollow groove 2143 of the second sub-mount 2142 is designed to reduce inertial effects by locally reducing weight, and meanwhile, the increased heat dissipation surface area improves heat conduction efficiency, so that the temperature rise problem of the actuating assembly 3 during operation is effectively relieved. The hollowed-out groove 2143 absorbs high-frequency vibration energy by adjusting local rigidity, so that resonance risk is reduced, influence of inertia on high-frequency dynamic response is reduced, and actuation accuracy is ensured. The platform section of the second sub-mount 2142 provides a stable anchoring point for the elastic member, and can compensate for small displacement caused by temperature or assembly errors by combining the flexible deformation capability of the hollow groove 2143, so as to maintain the close fit between the first rolling body 222 and the chute 12.

Referring to fig. 3, in some embodiments, the base assembly 2 further includes a second mounting structure 24, the second mounting structure 24 is connected to the first elastic member 23, and the first rolling element 222 is rotatably connected to the second mounting structure 24. The second mounting structure 24 provides a rigid mounting reference for the first rolling body 222, ensures accurate positioning of the rolling body 22 along a preset direction, reduces deflection caused by stress deformation, and enables the first elastic piece 23 to apply controllable pretightening force through the second mounting structure 24, so that the first rolling body 222 and a contact surface are always tightly attached, and vibration or precision loss caused by gaps is avoided. The second mounting structure 24 is a rigid reference, and the first elastic member 23 provides a flexible connection to reduce both direct frictional impact through the rigid portion and mechanical stress through the elastic member, thereby reducing the risk of wear of the first rolling body 222 in contact with the chute 12.

Referring to fig. 4, in some embodiments, the first elastic member 23 includes a first recess 231 and a second recess 232, the recess directions of the first recess 231 and the second recess 232 are opposite, the first recess 231 is disposed at two ends of the second recess 232 along the first direction, the middle portion of the first recess 231 contacts the second side 213, the first recess 231 includes a first end and a second end along the first direction, the first end and the second end are both disposed at intervals along the second direction with the second side 213, the first end is connected with the first mounting structure 214, the second end is connected with the second recess 232, the second recess 232 is disposed at intervals along the second direction with the second side 213, and the middle portion of the second recess 232 is rotatably connected with the first rolling body 222. The first recess 231 and the second recess 232 are configured to be recessed in opposite directions, so that the first elastic member 23 can be deformed in different directions when being compressed or stretched. For example, the first concave portion 231 may contract in a concave direction when pressed, and the second concave portion 232 may be deformed reversely, thereby dispersing stress concentration. This construction avoids the problem of excessive local stress caused by unidirectional deformation of the conventional single-recess elastic member, and prolongs the service life of the first elastic member 23. The two ends of the first concave 231 are respectively connected with the first mounting structure 214 and the second concave 232, so as to form a flexible supporting structure with fixed two ends and suspended middle. When the first rolling element 222 is acted by an external force, the middle part of the second concave part 232 can be elastically deformed to provide a pretightening force along the first direction, and meanwhile, the spacing design of the first concave part 231 and the second side surface 213 allows the first concave part and the second side surface 213 to slightly displace along the second direction, so as to adaptively adjust the contact pressure. This design dynamically compensates for assembly errors or thermal expansion/vibration excursions during operation, ensuring constant contact of the first rolling bodies 222 with the runner 12. The alternating concave structure of the first concave portion 231 and the second concave portion 232 increases the effective deformation path length of the first elastic member 23. When high frequency vibrations are transferred to the elastic member, the energy needs to be absorbed stepwise in a plurality of curved paths, achieving more efficient high frequency damping, which reduces the amplitude of the transfer of vibration energy to the mount body 21, reducing the risk of resonance. The middle part of the first recess 231 contacts the second side 213 to form a rigid fulcrum, and the middle part of the second recess 232 is connected to the first rolling element 222 to form a flexible connection point, so that the deformation of the elastic member is mainly restrained in the first direction, and unnecessary vibration modes perpendicular to the movement direction (such as the second direction or the third direction, which is the thickness direction of the actuating assembly 3) are restrained. For example, when the first rolling bodies 222 are subjected to lateral force, the deformation of the second concave portions 232 is restricted by the fixed ends of the first concave portions 231, avoiding multiaxial coupling vibration. The double recess structure realizes a larger effective elastic travel in a limited space, so that the first elastic member 23 has a higher energy storage density than a conventional linear spring in the same volume, and is beneficial to the miniaturization design of the motor stator 10.

The base assembly 2 of the present application includes the base body 21, the first elastic member 23, the first rolling bodies 221 and the first rolling bodies 222, which are arranged so that not only a sufficient clamping force can be provided but also a vibration mode thereof can be maintained to the maximum extent after the deformation of the piezoelectric ultrasonic actuator 31, thereby minimizing energy loss.

Referring to fig. 2, in some embodiments, the motor stator 10 further includes a second elastic member 25, the second elastic member 25 is located in the movable cavity 11, and two ends of the second elastic member 25 along the first direction are respectively connected to the outer wall of the base assembly 2 and the cavity wall of the movable cavity 11. The second elastic member 25 is added to buffer and provide a pre-tightening force between the base assembly 2 and the housing 1. In terms of buffering, the second elastic piece 25 can alleviate adverse effects generated by external vibration, impact and the like when the base assembly 2 operates, the internal actuating assembly 3 is protected, and in terms of pretightening force, the second elastic piece 25 ensures that the output driving foot 32 and the rotor keep a reasonable contact state, maintains the stability and the precision of the operation of the mechanism, and ensures that the piezoelectric motor 100 operates normally. In addition, the output performance of the piezoelectric motor 100 can be changed by adjusting the pre-tightening force of the second elastic member 25, thereby improving the motion characteristics of the motor.

In an alternative embodiment, the second elastic member 25 is connected to the side wall of the base body 21 opposite to the movable port thereof at one end in the first direction and to the cavity wall of the housing 1 at the other end.

Referring to fig. 2, in some embodiments, the base assembly 2 and the actuating assembly 3 each include two base assemblies 2, the actuating assembly 3 is connected to one base assembly 2, and the two base assemblies 2 are stacked and spaced apart along the thickness direction of the actuating assembly 3. In other words, the movable cavity 11 of the housing 1 is internally provided with two base assemblies 2 and actuating assemblies 3 with the same specification, so as to achieve the effect of multi-foot driving, and the motor stator 10 has a compact overall structure and perfect functions.

In order to ensure accuracy of the operation position of the piezoelectric ultrasonic actuator 31 at the time of deformation, the base assembly 2 is designed to fix the piezoelectric ultrasonic actuator 31. The design not only simplifies the whole structure, but also makes the assembly of the motor stator 10 more convenient, and simultaneously ensures the transmission precision of the motor stator 10. In addition, due to the special structure of the motor stator 10, two-phase signals are required when driving the piezoelectric motor 100. Typically, as the number of drive feet increases, the number of signal paths that need to be controlled increases. However, the present invention employs two identical base assemblies 2 and actuating assemblies 3, and by simultaneously exciting the same sections of the ceramic layers of the two piezoelectric ultrasonic actuators 31, the ceramic layers are equally deformed, thus ensuring that the piezoelectric motor 100 can be driven by only two channels even if the number of driving feet is increased. The control complexity is simplified while the output force of the motor is ensured to be increased.

Referring to fig. 7, in a second aspect, an embodiment of the present application provides a piezoelectric motor 100, where the piezoelectric motor 100 includes a motor stator 10 and a motor mover 20. The motor stator 10 is drivingly connected to the motor mover 20 in a first direction, and the motor stator 10 is the motor stator 10 of the first aspect. The piezoelectric motor 100 has all the technical effects of the motor stator 10 of the embodiment of the present application.

Referring to fig. 6, in some embodiments, the piezoelectric motor 100 further includes a friction member 30, where the friction member 30 is connected to the motor rotor 20 and disposed between the motor stator 10 and the motor rotor 20 along the first direction. The friction piece 30 is used for contacting with the output driving foot 32 of the motor stator 10, the periodic elliptical motion track friction generated by the output driving foot 32 of the motor stator 10 transmits vibration energy to the friction piece 30, and particles on the surface of the motor stator 10 periodically contact with the friction piece 30 under high-frequency vibration to form impact-sliding motion so as to drive the motor rotor 20.

In an alternative embodiment, friction member 30 is a ceramic friction bar.

Referring to fig. 6, in some embodiments, the piezoelectric motor 100 further includes a motor base 40, the motor mover 20 is disposed on the motor base 40, and the motor stator 10 is movably connected to the motor base 40 along the first direction. The motor base 40 is arranged, so that the motor rotor 20 and the motor stator 10 are both arranged on the electrode base, the relative positions of the motor rotor 20 and the motor stator 10 can be ensured, and the operation precision of the piezoelectric motor 100 can be ensured.

Referring to fig. 5, in some embodiments, the motor base 40 is concavely provided with a movable slot 401 along a first direction, the motor rotor 20 is located outside the movable slot 401, the piezoelectric motor 100 further includes a sliding component 402 and a positioning fastener, the sliding component 402 is located in the movable slot 401, the sliding component 402 is connected to a bottom wall of the movable slot 401, the motor stator 10 is connected to the sliding component 402, one end of the positioning fastener along the first direction is connected to a side wall of the movable slot 401, the other end of the positioning fastener is abutted to the motor stator 10, and the positioning fastener is used for adjusting a position of the motor stator 10 along the first direction. The motor stator 10 is taken as a whole and is fixed in the movable groove 401 of the motor base 40, and the motor stator 10 is fixed through the sliding component 402, so that the motor stator 10 is prevented from shifting in the first direction, the friction piece 30 of the motor rotor 20 and the output driving foot 32 of the motor stator 10 are ensured to be in full contact, and the running accuracy of the motor is ensured. The positioning fastener enables the motor stator 10 to realize adjustable pre-pressure, the rear end of the shell 1 of the motor stator 10, which is far away from the motor rotor 20 along the first direction, is fixed through the positioning fastener, and the pre-pressure between the motor stator 10 and the friction piece 30 of the motor rotor 20 is adjusted by rotating the positioning fastener, so that the motor stator 10 and the motor rotor 20 are ensured to be in stable contact.

Referring to fig. 5, in some embodiments, the sliding assembly 402 includes a sliding rail 4021 and a sliding block 4022, the sliding rail 4021 is connected to a bottom wall of the movable slot 401, and the sliding block 4022 is connected to the motor stator 10. The sliding component 402 is provided with the sliding rail 4021 and the sliding block 4022, so that the motor stator 10 can be prevented from being offset in the first direction and the second direction, the friction piece 30 of the motor rotor 20 and the output driving foot 32 of the motor stator 10 can be ensured to be in full contact, and the running precision of the piezoelectric motor 100 is ensured.

The specific working principle of the motor stator 10 according to the embodiment of the present application will be described below, in which, according to the principle of combining longitudinal vibration and bending vibration, high-frequency voltage excitation signals with a phase difference of 90 ° are applied to two opposite angle sides of the motor stator 10, respectively, under the condition that the influence of the disturbance mode of the motor stator 10 on the working mode is ignored, so that the first-order longitudinal vibration mode response and the second-order bending vibration mode response of the motor stator 10 are excited simultaneously. It can be seen that the first order longitudinal vibration displacement response and the second order flexural vibration displacement response of the motor stator 10 are out of phase in time. At the same time, the second order bending vibration displacement direction of the motor stator 10 is always perpendicular to the first order bending vibration displacement direction at the peaks and troughs, which indicates that there is also a phase difference in space. Namely, when the bending vibration of the motor stator 10 reaches the amplitude, the longitudinal elongation thereof reaches the maximum, and thus the elliptical motion track can be realized at the output driving foot 32.

When the motor stator 10 is gradually shifted from the maximum bending deformation position shown in fig. 8 (a) to the maximum elongation position shown in fig. 8 (b). During this change, the motor stator 10 moves from the maximum position of the bending vibration, as it lengthens longitudinally, to the equilibrium position of the bending vibration and contacts the motor mover 20. By virtue of the friction force, the motor stator 10 drives the motor mover 20 to move rightward by one step, and the output drive foot 32 rotates around the z-axis in the x-axis negative direction and the y-axis positive direction, and at this stage, the output drive foot 32 is always kept in contact with the motor mover 20.

When the motor stator 10 is changed stepwise from the maximum extension position shown in fig. 8 (b) to the maximum bending deformation position shown in fig. 8 (c), the bending direction is reversed from that in fig. 8 (a). During this change, the motor stator 10 moves from the maximum position of longitudinal elongation to the maximum position of reverse bending deformation, while maintaining contact with the motor mover 20. By friction force, the motor stator 10 continuously drives the motor mover 20 to move rightward, and the output drive foot 32 rotates around the z-axis positive x-axis direction and the y-axis positive y-axis direction, and at this stage, the output drive foot 32 is still in contact with the motor mover 20.

At this time, the motor stator 10 is gradually shifted from the reverse maximum bending deformation position shown in fig. 8 (c) to the longitudinal extension shortest position shown in fig. 8 (d). During this change, the motor stator 10 moves from the maximum position of reverse bending deformation to the limit position of longitudinal expansion. During this driving, the output driving foot 32 and the motor mover 20 are separated from each other, and the output driving foot 32 rotates around the z-axis x-axis positive direction and the y-axis negative direction.

When the motor stator 10 is shifted from the longitudinally telescoping shortest position shown in fig. 8 (d), it is gradually shifted to the maximum bending deformation limit position shown in fig. 8 (a). During this change, the motor mover 20 moves from the extreme position of longitudinal expansion and contraction to the maximum position of bending deformation, the output driving foot 32 is always in a separated state from the motor mover 20 in the whole process, and the output driving foot 32 rotates around the z-axis in the x-axis negative direction and the y-axis negative direction.

As can be seen from the four steps described above, the output drive foot 32 of the motor stator 10 will complete an elliptical motion in one cycle. Therefore, the output driving foot 32 of the motor stator 10 can be closely attached to the motor mover 20 under the condition that a certain pre-pressing force is applied. At this time, the motor mover 20 is pushed to make a linear motion by the friction force generated between the motor stator 10 and the friction member 30. Similarly, when the driving voltage signal is changed, the motion track of the motor stator 10 is reversed, so that the motor rotor 20 realizes the reverse motion.

It should be noted that the present piezoelectric motor has the following problems:

The multi-component assembly results in reduced motor reliability, and in order to improve the output performance of the piezoelectric motor, a method of increasing the number of driving feet is generally employed. The method can effectively improve the output force of the motor, but can lead to the motor structure becoming more complex and the design difficulty increasing, secondly, higher precision is needed during assembly to ensure that each driving foot can work cooperatively, which puts higher requirements on assembly, and furthermore, more driving feet can possibly introduce additional vibration mode interference to influence the stability and energy transmission efficiency of the motor.

The output efficiency of the motor is reduced after the motor structure is optimized, and in order to better excite the working mode of the motor stator, the ultrasonic motor driven by multiple feet usually adopts a design method for slotting an elastomer. However, this design fails to adequately account for the matching of mover and stator motion, resulting in significant loss of energy transfer during operation, thereby reducing vibrational energy transfer efficiency.

The driving at ultrasonic frequency causes that the motor precision is difficult to ensure, and the friction coefficient, the pretightening force and the contact area are key parameters for ensuring the energy transmission efficiency. However, the motor stator structure is often subjected to tiny deformation due to insufficient rigidity under high-frequency vibration, and tiny lateral force can be generated due to uneven pretightening force distribution, in addition, ultrasonic antifriction phenomenon of the driving foot occurs under the high-frequency driving condition, and the contact area can be changed due to thermal expansion of materials caused by temperature rise. These factors together lead to positioning deviation, and then reduce motion accuracy, make the motor be difficult to reach the nanoscale requirement.

The control complexity caused by the multi-foot driving is that in the multi-foot ultrasonic motor, a plurality of piezoelectric ceramic driving units are required to realize the movement of the stator through cooperative work. Typically, each drive unit requires an independent signal path and precise phase differences between the signals must be maintained to produce the desired vibration modes. In addition, because the operating frequency of the ultrasonic motor is high (typically above 20 kHz), the circuit needs to have high-frequency signal processing capability. Therefore, circuit design and debugging of the multi-foot ultrasonic motor tend to be complex.

The complex structure is mainly characterized in that the design difficulty, the assembly precision requirement and the vibration mode interference are caused by the increase of the number of the driving feet, and the control complexity is characterized in that the independent signal channels, the precise phase difference control and the high-frequency signal processing capability are required by the cooperative work of the multiple driving units. Solving these problems requires optimizing the layout and assembly process of the drive foot in terms of structural design, while improving the accuracy and efficiency of signal processing in the control system to achieve a balance of motor performance and complexity.

The embodiment of the application uses the housing 1, the base assembly 2 and the actuating assembly 3 as a single module. So that they have standardized positioning and dimensions, ensuring that they can be interchanged and flexibly combined. The necessary support and fixing structures are integrated inside the module to reduce the reliance on external components. Not only reduces the assembly difficulty and simplifies the assembly process, but also improves the assembly precision. The two piezoelectric ultrasonic actuators 31 are independently assembled and debugged in the motor stator 10, and if one piezoelectric ultrasonic actuator 31 fails, the piezoelectric ultrasonic actuators can be independently detected and replaced, so that the overhaul and maintenance efficiency is improved. The motor base 40 has a guiding function in the first direction and the second direction by providing the movable groove 401. In addition, the unique base assembly 2 design retains the ability to deform the piezoelectric ultrasonic actuator 31 to a maximum extent while retaining the piezoelectric ultrasonic actuator 31, so that the energy generated by the deformation of the piezoelectric ultrasonic actuator 31 can be more efficiently transferred to the output drive foot 32. The design not only reduces energy loss, but also remarkably improves the operation efficiency of the motor. And the pre-pressure of the motor stator 10 is regulated by the positioning fastener, so that the motor realizes speed regulation. The piezoelectric motor 100 of the embodiment of the application avoids energy loss caused by slotting and reduces the complexity of processing. The motor stator 10 changes the traditional patch structure, adopts a piezoelectric stacking method, and solves the problem that the number of channels is increased due to the increase of the number of driving feet. The method makes the channel number and the driving foot number not related, even if the driving foot number is increased, the driving can be realized by only two channels, and the control difficulty is simplified while the output force is increased.

In the description of the present application, it should be understood that, if any, these terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., are used herein with respect to the orientation or positional relationship shown in the drawings, these terms refer to the orientation or positional relationship for convenience of description and simplicity of description only, and do not indicate or imply that the apparatus or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the application.

Furthermore, the terms "first," "second," and the like, if any, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present application, the terms "plurality" and "a plurality" if any, mean at least two, such as two, three, etc., unless specifically defined otherwise.

In the present application, unless explicitly stated and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly. For example, they may be fixedly connected, detachably connected or integrally formed, mechanically connected, electrically connected, directly connected or indirectly connected through an intermediate medium, and communicated between two elements or the interaction relationship between two elements unless clearly defined otherwise. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art according to the specific circumstances.

In the present application, unless expressly stated or limited otherwise, the meaning of a first feature being "on" or "off" a second feature, and the like, is that the first and second features are either in direct contact or in indirect contact through an intervening medium. Moreover, a first feature being "above," "over" and "on" a second feature may be a first feature being directly above or obliquely above the second feature, or simply indicating that the first feature is level higher than the second feature. The first feature being "under", "below" and "beneath" the second feature may be the first feature being directly under or obliquely below the second feature, or simply indicating that the first feature is less level than the second feature.

It will be understood that if an element is referred to as being "fixed" or "disposed" on another element, it can be directly on the other element or intervening elements may also be present. If an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like as used herein, if any, are for descriptive purposes only and do not represent a unique embodiment.

The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above examples illustrate only a few embodiments of the application, which are described in detail and are not to be construed as limiting the scope of the claims. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the application, which are all within the scope of the application. Accordingly, the scope of protection of the present application is to be determined by the appended claims.

Claims (10)

1. A motor stator, comprising:

a housing provided with a movable cavity;

the base component can be movably connected with the cavity wall of the movable cavity;

The actuating assembly is connected with the base assembly and used for driving the base assembly to move along a first direction relative to the shell, and the first direction is intersected with the thickness direction of the actuating assembly.

2. The motor stator of claim 1, wherein the base assembly comprises a base body and a rolling body, the actuating assembly is connected to the base body, the rolling body is rotatably connected to the base body, a sliding groove is formed in a cavity wall of the movable cavity, and the rolling body is slidably arranged in the sliding groove.

3. The motor stator of claim 2, wherein the base assembly further comprises a first elastic member, the rolling bodies comprise a first rolling body and a second rolling body, the base body comprises a first side surface and a second side surface which are opposite to each other along a second direction, the first rolling body is rotatably connected to the first side surface, the first elastic member is connected to the second side surface along two ends of the first direction, the second rolling body is rotatably connected to the first elastic member, and the second direction intersects with the first direction and the thickness direction of the actuating assembly, and the first direction, the second direction, the thickness direction, the second direction, the third direction, and the actuating assembly are not coplanar.

4. The motor stator of claim 1, further comprising a second elastic member positioned within the movable cavity, the second elastic member being connected to an outer wall of the base assembly and a cavity wall of the movable cavity along the first direction.

5. The motor stator of claim 1 wherein the actuation assembly includes a piezoelectric ultrasonic actuator coupled to the base assembly and an output drive foot coupled to an end of the piezoelectric ultrasonic actuator in the first direction, the piezoelectric ultrasonic actuator for driving movement of the base assembly in the first direction to move the output drive foot relative to the housing.

6. The motor stator according to claim 1, wherein the base assembly and the actuating assembly each include two, the actuating assemblies are respectively connected to one of the base assemblies, and the two base assemblies are stacked and spaced apart in a thickness direction of the actuating assembly.

7. A piezoelectric motor, characterized in that the piezoelectric motor comprises a motor stator and a motor mover, the motor stator being drivingly connected to the motor mover in a first direction, the motor stator being a motor stator according to any one of claims 1 to 6.

8. The piezoelectric motor according to claim 7, further comprising a friction member connected to the motor mover and disposed between the motor stator and the motor mover in the first direction.

9. The piezoelectric motor according to claim 7, further comprising a motor base, wherein the motor mover is disposed on the motor base, and wherein the motor stator is movably connected to the motor base in the first direction.

10. The piezoelectric motor according to claim 9, wherein the motor base is concavely provided with a movable groove along the first direction, the motor mover is located outside the movable groove, the piezoelectric motor further comprises a sliding assembly and a positioning fastener, the sliding assembly is arranged in the movable groove, the sliding assembly is connected to the bottom wall of the movable groove, the motor stator is connected to the sliding assembly, one end of the positioning fastener along the first direction is connected to the side wall of the movable groove, the other end of the positioning fastener is abutted to the motor stator, and the positioning fastener is used for adjusting the position of the motor stator along the first direction.