Motor stator and piezoelectric motor

Abstract

The invention relates to the technical field of piezoelectric motors, in particular to a motor stator and a piezoelectric motor. The motor stator comprises a shell, a base assembly and an actuating assembly. The shell is provided with a movable cavity; the base assembly is movably connected to the cavity wall of the movable cavity; the actuating assembly is connected to the base assembly and used for driving the base assembly to move in the first direction relative to the shell, and the first direction intersects with the thickness direction of the actuating assembly. The movable connection of the base assembly can change the overall resonant frequency of the motor stator by adjusting the rigidity, so that the overall resonant frequency is matched with the working frequency of the actuating assembly, and the energy transfer efficiency is maximized. By additionally arranging the base assembly, energy can be efficiently transmitted, energy loss is reduced, and the operation efficiency of the piezoelectric motor is improved.

Description

Technical Field

[0001] The present application relates to the technical field of piezoelectric motors, and in particular, to a motor stator and a piezoelectric motor. Background Art

[0002] At present, the energy generated by the deformation of the piezoelectric ultrasonic actuator of a piezoelectric motor is difficult to be efficiently transmitted, resulting in relatively high energy loss and reducing the operating efficiency of the piezoelectric motor.

[0003] The information disclosed in this background art section is only intended to enhance the overall understanding of the present invention and should not be regarded as an admission or any form of suggestion that this information constitutes prior art already known to those of ordinary skill in the art. Summary of the Invention

[0004] Based on this, in view of the problem that the energy generated by the deformation of the piezoelectric ultrasonic actuator of the current piezoelectric motor is difficult to be efficiently transmitted, resulting in relatively high energy loss and reducing the operating efficiency of the piezoelectric motor, it is necessary to provide a motor stator and a piezoelectric motor.

[0005] In a first aspect, a motor stator includes:

[0006] A housing provided with a movable cavity;

[0007] A base assembly movably connected to the cavity wall of the movable cavity;

[0008] An actuating assembly connected to the base assembly, the actuating assembly being configured to drive the base assembly to move relative to the housing along a first direction, the first direction intersecting the thickness direction of the actuating assembly.

[0009] In one embodiment, the base assembly includes a base body and rolling elements, the actuating assembly is connected to the base body, the rolling elements are rotatably connected to the base body, a chute is recessed in the cavity wall of the movable cavity, and the rolling elements are slidably disposed in the chute.

[0010] In one embodiment, the base assembly further includes a first elastic member, the rolling elements include a first rolling element and a second rolling element, the base body includes a first side surface and a second side surface oppositely disposed along a second direction, the first rolling element is rotatably connected to the first side surface, two ends of the first elastic member in the first direction are connected to the second side surface, the second rolling element is rotatably connected to the first elastic member, the second direction intersects the first direction and the thickness direction of the actuating assembly pairwise, and the three are not coplanar.

[0011] In one embodiment, the motor stator further includes a second elastic member located in the movable cavity. Two ends of the second elastic member in the first direction are respectively connected to the outer wall of the base assembly and the cavity wall of the movable cavity.

[0012] In one embodiment, the actuating assembly includes a piezoelectric ultrasonic actuator and an output driving foot. The piezoelectric ultrasonic actuator is connected to the base assembly. The output driving foot is connected to one end of the piezoelectric ultrasonic actuator in the first direction. The piezoelectric ultrasonic actuator is configured to drive the base assembly to move in the first direction, so that the output driving foot moves relative to the housing.

[0013] In one embodiment, both the base assembly and the actuating assembly include two. The actuating assemblies are respectively connected to one of the base assemblies. The two base assemblies are stacked and spaced apart in the thickness direction of the actuating assembly.

[0014] In a second aspect, a piezoelectric motor includes a motor stator and a motor rotor. The motor stator is drivingly connected to the motor rotor in a first direction. The motor stator is the motor stator as described in the first aspect.

[0015] In one embodiment, the piezoelectric motor further includes a friction member connected to the motor rotor and disposed between the motor stator and the motor rotor in the first direction.

[0016] In one embodiment, the piezoelectric motor further includes a motor base. The motor rotor is disposed on the motor base. The motor stator is movably connected to the motor base in the first direction.

[0017] In one embodiment, the motor base is recessed with a movable groove in the first direction. The motor rotor is located outside the movable groove. The piezoelectric motor further includes a sliding assembly and an adjustment fastener. The sliding assembly is disposed in the movable groove and connected to the bottom wall of the movable groove. The motor stator is connected to the sliding assembly. One end of the adjustment fastener in the first direction is connected to the side wall of the movable groove, and the other end abuts against the motor stator. The adjustment fastener is used to adjust the position of the motor stator in the first direction.

[0018] The actuation component of the above-mentioned motor stator converts electrical energy into mechanical vibration through the inverse piezoelectric effect. However, when it is directly fixed to the housing, the vibration energy may be scattered or reflected due to the impedance mismatch at the interface (for example, if the housing is too rigid, the energy cannot be effectively transmitted). As an intermediate flexible connection structure, the base component matches the mechanical impedance of the actuation component and the housing through a movable connection, enabling the vibration energy to be transmitted to the housing or the load more efficiently. At the same time, the base component can adjust the pre-tightening force between the actuation component and the housing, reducing the dissipation of energy during the transmission process. The movable connection of the base component can reduce the rigid friction between the actuation component and the housing, further reducing the frictional loss. The degrees of freedom of movement of the base component can constrain the vibration direction, suppress irrelevant vibration modes, concentrate the energy in the effective driving direction, and avoid energy waste caused by multi-directional vibration. The movable connection of the base component can change the overall resonance frequency of the motor stator by adjusting the stiffness, making it match the operating frequency of the actuation component, thereby maximizing the energy transmission efficiency. Therefore, by adding the base component, the energy can be transmitted efficiently, the energy loss can be reduced, and the operating efficiency of the piezoelectric motor can be improved. Description of the Drawings

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the disclosed drawings.

[0020] Figure 1 It is a schematic structural diagram of a motor stator provided by an embodiment of the present application.

[0021] Figure 2 It is a schematic internal structural diagram of a motor stator provided by an embodiment of the present application.

[0022] Figure 3 It is a schematic structural diagram of a base component and an actuation component provided by an embodiment of the present application.

[0023] Figure 4 It is a front view of a base component and an actuation component provided by an embodiment of the present application.

[0024] Figure 5 It is a schematic structural diagram of a motor base and a motor stator provided by an embodiment of the present application.

[0025] Figure 6 It is a schematic structural diagram of an electrode base, a motor stator, and a motor mover provided by an embodiment of the present application.

[0026] Figure 7 It is a schematic structural diagram of a piezoelectric motor provided by an embodiment of the present application.

[0027] Figure 8 In Figure (a), it is a schematic diagram of the motor stator in the first working state; Figure 8 In Figure (b), it is a schematic diagram of the motor stator in the second working state; Figure 8 In Figure (c), it is a schematic diagram of the motor stator in the third working state; Figure 8 In Figure (d), it is a schematic diagram of the motor stator in the fourth state.

[0028] Explanation of reference numerals: 100, piezoelectric motor; 10, motor stator; 1, housing; 11, movable cavity; 12, chute; 2, base assembly; 21, base body; 211, card slot; 212, first side; 213, second side; 214, first mounting structure; 2141, first sub-mounting body; 2142, second sub-mounting body; 2143, hollow groove; 215, blocking body; 22, rolling body; 221, first rolling body; 222, second rolling body; 23, first elastic member; 231, first recess; 232, second recess; 24, second mounting structure; 25, second elastic member; 3, actuation assembly; 31, piezoelectric ultrasonic actuator; 32, output driving foot; 20, motor mover; 30, friction member; 40, motor base; 401, movable groove; 402, sliding assembly; 4021, slide rail; 4022, slider. Detailed implementation manners

[0029] To make the above objects, features, and advantages of the present application more obvious and understandable, the following will describe in detail the specific implementation manners of the present application with reference to the accompanying drawings. Many specific details are set forth in the following description to fully understand the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present application. Therefore, the present application is not limited by the specific embodiments disclosed below.

[0030] Please refer to Figure 1 In a first aspect, an embodiment of the present application provides a motor stator 10. Please refer to Figure 2 The motor stator 10 includes a housing 1, a base assembly 2, and an actuation assembly 3. The housing 1 is provided with a movable cavity 11; the base assembly 2 is movably connected to the cavity wall of the movable cavity 11; the actuation assembly 3 is connected to the base assembly 2, and the actuation assembly 3 is used to drive the base assembly 2 to move relative to the housing 1 along a first direction (such as Figure 2The movement in the Y direction (as shown) is such that the first direction intersects the thickness direction of the actuating component 3. The actuating component 3 of the motor stator 10 converts electrical energy into mechanical vibration through the inverse piezoelectric effect. However, when directly fixed to the housing 1, the vibration energy may be scattered or reflected due to interface impedance mismatch (such as when the housing 1 is too rigid and the energy cannot be effectively transmitted). The base component 2, as an intermediate flexible connection structure, matches the mechanical impedance of the actuating component 3 and the housing 1 through a movable connection, enabling the vibration energy to be transmitted to the housing 1 or the load more efficiently. At the same time, the base component 2 can adjust the pre-tightening force between the actuating component 3 and the housing 1, reducing the dissipation of energy during transmission. The movable connection of the base component 2 can reduce the rigid friction between the piezoelectric ultrasonic braking component and the housing 1, further reducing frictional losses. The degrees of freedom of movement of the base component 2 can restrict the vibration direction, suppress irrelevant vibration modes, concentrate the energy in the effective driving direction, and avoid energy waste caused by multi-directional vibration. The movable connection of the base component 2 can change the overall resonance frequency of the motor stator 10 by adjusting the stiffness, making it match the operating frequency of the actuating component 3, thereby maximizing the energy transmission efficiency. Thus, by adding the base component 2, the energy can be efficiently transmitted, energy losses can be reduced, and the operating efficiency of the piezoelectric motor 100 can be improved.

[0031] Please refer to Figure 1 , in an alternative embodiment, the shape of the housing 1 is a cube. The housing 1 includes a bottom wall, side walls, and a top wall. The side walls are disposed between the bottom wall and the top wall in the thickness direction of the housing 1. The bottom wall, side walls, and top wall together define an activity cavity 11. The side walls are provided with activity ports communicating with the activity cavity 11. The base component 2 is movably connected to the side walls, and the base component 2 is movably inserted through the activity ports in the first direction.

[0032] Please refer to Figure 3 , in some embodiments, the actuating component 3 includes a piezoelectric ultrasonic actuator 31 and an output driving foot 32. The piezoelectric ultrasonic actuator 31 is connected to the base component 2, and the output driving foot 32 is connected to one end of the piezoelectric ultrasonic actuator 31 in the first direction (such as Figure 3 the Y direction as shown), and the piezoelectric ultrasonic brake is used to drive the base component 2 to move in the first direction so that the output driving foot 32 moves relative to the housing 1.

[0033] The piezoelectric ultrasonic actuator 31 provided by the embodiment of the present application includes a ceramic layer, an insulating layer, internal electrodes, and external electrodes inside. The main material of the ceramic layer is lead zirconate titanate, and the electric domains are arranged directionally after polarization. Under the action of an electric field, it will generate mechanical deformation, which is the core component for the piezoelectric ultrasonic actuator 31 to achieve electromechanical conversion. The insulating layer is located between or at the edge of the ceramic layers, playing the role of electrical insulation, effectively preventing the short circuit of the internal electrodes, and ensuring the normal operation of the actuator. The internal electrodes are cross-layer stacked and embedded between the ceramic layers along the thickness direction of the piezoelectric ultrasonic actuator 31, using a silver-palladium alloy material, for applying a driving electric field to achieve the conversion of electrical energy into mechanical energy. The external electrodes are electrically connected to the internal electrodes, providing an interface for the external circuit, facilitating the access of the driving voltage, and enabling the external electrical energy to be smoothly input into the piezoelectric ultrasonic actuator 31 to drive the ceramic layer to generate mechanical deformation.

[0034] The electromechanical conversion principle of the motor stator 10 provided by the embodiment of the present application is as follows: After applying a voltage to the thickness direction (the third direction, such as Figure 3 the Z direction shown) of the piezoelectric ultrasonic actuator 31, it deforms in the length direction (the first direction, such as Figure 3 the Y direction shown). This is based on the piezoelectric effect of the ceramic layer inside the piezoelectric ultrasonic actuator 31. When a driving voltage is applied to the thickness direction of the ceramic layer, due to the change in the directional arrangement of the electric domains in the ceramic layer under the action of the electric field, the ceramic layer generates mechanical deformation in the length direction. The internal electrodes are responsible for applying the driving electric field, and the external electrodes access the driving voltage. The two work together to convert electrical energy into the mechanical energy of the ceramic layer.

[0035] It should be noted that the current piezoelectric motor 100 relies on the combination of piezoelectric ceramic sheets and elastomers for driving. The motor stator 10 provided by the embodiment of the present application is composed of cross-stacked ceramic layers and internal electrodes, and the piezoelectric ultrasonic actuator 31 is divided into a pairwise symmetric structure through different polarization zones. This structure avoids the pasting between the current piezoelectric ceramic sheets and elastomers, can directly transfer the energy generated by the deformation of the ceramic layer to the output driving foot 32, reduces energy loss, and increases the output efficiency.

[0036] The output driving foot 32 is made of silicon nitride material or alumina material, and the output driving foot 32 is sintered at the end of the ceramic layer of the piezoelectric ultrasonic actuator 31. The output driving foot 32 can convert the mechanical energy generated by the deformation of the ceramic layer into a directional frictional force, achieve energy conversion, drive the electrode mover to move, and at the same time, under the condition of high-frequency vibration and continuous contact friction, the output driving foot 32 can ensure the structural integrity of the piezoelectric ultrasonic actuator 31.

[0037] In an alternative embodiment, the way of the base assembly 2 being movably connected to the housing 1 can be a sliding connection or a rolling connection, etc.

[0038] Please refer to Figure 3, Preferably, in some embodiments, the base assembly 2 includes a base body 21 and rolling elements 22. The rolling elements 22 are rotatably connected to the base body 21. The actuating assembly 3 is connected to the base body 21. A chute 12 is recessed in the cavity wall of the moving cavity 11 (please refer to Figure 2 ), and the rolling elements 22 are slidably disposed in the chute 12. The frictional resistance of the rolling elements 22 is less than sliding friction, significantly reducing the energy loss between the base assembly 2 and the housing 1, enabling the vibration energy of the actuating assembly 3 to be more efficiently transmitted to the housing 1, and avoiding the dissipation of mechanical energy converted into heat due to friction. Rolling contact allows the base assembly 2 to respond to high-frequency vibrations with a lower starting threshold, ensuring that the minute deformation of the piezoelectric ceramic can be quickly converted into a directional movement, improving the driving efficiency. The rolling elements 22 can reduce the motion jamming caused by instantaneous static friction in a vibrating environment, ensuring the continuous and stable operation of the piezoelectric motor 100. The geometric fit between the chute 12 and the rolling elements 22 forms a one-dimensional kinematic pair, concentrating the vibration energy of the ceramic layer on the effective driving axis. The stiffness characteristics of the rolling connection can suppress high-order vibration modes, avoiding energy dispersion caused by parasitic vibrations. The rolling elements 22 can automatically balance the pre-tightening force between the piezoelectric assembly and the housing 1 within the chute 12, ensuring that the contact interface is always in a better stress state. Therefore, setting the base assembly 2 as the base body 21 and the rolling elements 22 can reduce frictional losses, improve energy efficiency, extend the service life and reliability of the base assembly 2, precisely constrain the vibration direction, and suppress energy dissipation; in addition, it can also achieve dynamic adjustment of the pre-tightening force and impedance matching.

[0039] In an alternative embodiment, the rolling elements 22 can be balls or rollers, etc.

[0040] Please refer to Figure 3 , in some embodiments, the rolling elements 22 are disposed on the side surface of the base body 21 along the second direction (such as the X direction as shown in Figure 3 ). The base body 21 is provided with a slot 211 along the first direction (such as the Y direction as shown in Figure 3 ). The slot 211 penetrates the base body 21 along the third direction (such as the Z direction as shown in Figure 3 ). The third direction is the thickness direction of the actuating assembly 3. The third direction intersects the second direction and the first direction pairwise, and the three are not coplanar. The actuating assembly 3 is clamped in the slot 211. The base body 21 clamps the actuating assembly 3 through the slot 211 provided along the first direction and penetrating the third direction, which can achieve three-dimensional positioning and constraint of the actuating assembly 3, avoiding the deviation of the vibration direction or energy dissipation caused by assembly deviation. The rigid clamping of the slot 211 can evenly distribute the pre-tightening force between the actuating assembly 3 and the base body 21, preventing microcracks in the ceramic layer or interface peeling caused by local stress concentration. At the same time, the slot 211 is along the driving direction (the first direction, such as Figure 3The extension design in the Y direction (as shown) allows the piezoelectric component to deform along a specified path when excited, reducing lateral vibration interference and enabling efficient energy transfer to the output driving foot 32.

[0041] In an alternative embodiment, the slot 211 of the base body 21 has a retaining body 215 protruding into the slot 211 from the top wall and the bottom wall of the slot in the third direction (such as Figure 3 the Z direction as shown) in the second direction (such as Figure 3 the X direction as shown). The retaining body 215 is used to limit the movement of the actuating component 3 in the third direction.

[0042] In an alternative embodiment, there are four retaining bodies 215, and the four retaining bodies 215 are provided at both ends of the base body 21 in the first direction.

[0043] In some embodiments, the base assembly 2 further includes a first elastic member 23. The rolling body 22 includes a first rolling body 221 and a first rolling body 222. The base body 21 includes a first side surface 212 and a second side surface 213 that are oppositely arranged in the second direction. The first rolling body 221 is rotatably connected to the first side surface 212. The two ends of the first elastic member 23 in the first direction are connected to the second side surface 213. The first rolling body 222 is rotatably connected to the first elastic member 23. The second direction intersects the first direction and the thickness direction of the actuating component 3 pairwise, and the three are not coplanar. The additional first elastic member 23 connecting the first rolling body 222 is used to prevent the excessive movement of the actuating component 3 and ensure the stability of operation. The elastic deformation of the first elastic member 23 can continuously provide an appropriate pre-tightening force for the first rolling body 222 to ensure a constant contact between the first rolling body 222 and the chute 12, avoiding vibrations or positioning errors caused by gaps. The first elastic member 23 attenuates high-frequency vibration energy through its damping characteristics, reduces the amplitude transmitted to the base body 21, and at the same time buffers the inertial impact when the movement direction suddenly changes, extending the service life of the base assembly 2. The first elastic member 23 allows a small displacement of the first rolling body 222 in the first direction. This controllable degree of freedom not only tolerates manufacturing errors but also prevents multi-axis coupled vibrations through elastic constraints, improving the movement smoothness.

[0044] Please refer to Figure 3 In some embodiments, both the first side surface 212 and the second side surface 213 protrude with a first mounting structure 214 in the second direction (such as Figure 3 the X direction as shown). The first rolling body 221 is rotatably connected to the first mounting structure 214 on the first side surface 212. The first elastic member 23 is in the first direction (such as Figure 3The two ends in the Y direction (as shown) are respectively connected to the first mounting structure 214 on the second side surface 213. The protruding first mounting structure 214 provides a rigid positioning reference for the installation of the first rolling elements 221, the first rolling elements 222 and the first elastic member 23, ensuring the precise installation of each component along the preset direction. The protruding first mounting structure 214 enhances the support strength of the contact surface, reduces the offset caused by force-induced deformation, and thus improves the stability of the movement trajectory. The first elastic member 23 is connected to the first rolling elements 222 through the first mounting structure 214, and can apply a controllable pre-tightening force to ensure that the rolling elements 22 are always in close contact with the contact surface, avoiding vibration or accuracy loss caused by gaps. The flexible deformation ability of the first elastic member 23 can compensate for the small displacements generated 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 maintain the optimal contact state between the first rolling elements 222 and the chute 12. The first rolling elements 221 are directly mounted on the protruding rigid first mounting structure 214, while the first rolling elements 222 are connected through the first elastic member 23, forming a rigid + elastic hybrid support structure. In this way, both the direct friction impact is reduced through the rigid first mounting structure 214, and the high-frequency vibration is absorbed through the first elastic member 23, which can improve the movement smoothness and service life.

[0045] Please refer to Figure 3 and Figure 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 spaced apart along a first direction. There are two first rolling elements 221, which are rotatably connected to the first sub-mounting body 2141 and the second sub-mounting body 2142 of the first side surface 212 respectively. The 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. The cross-sectional area of the first sub-mounting body 2141 gradually increases along the second direction and in the direction pointing to itself. The cross-sectional area of the second sub-mounting body 2142 first increases and then remains unchanged along the second direction and in the direction pointing to itself. The second sub-mounting body 2142 is provided with a hollow groove 2143 penetrating along a third direction. The wedge-shaped cross-section (gradually increasing along the second direction) of the first sub-mounting body 2141 can evenly disperse the stress in the stress-bearing area, avoiding fatigue fracture caused by local stress concentration. The cross-section of the second sub-mounting body 2142 first increases and then remains stable, forming a rigid support platform, further suppressing the force-induced deformation and enhancing the structural stability. The design of the hollow groove 2143 of the second sub-mounting body 2142 reduces the inertial influence through local weight reduction. At the same time, the increased heat dissipation surface area improves the heat conduction efficiency, effectively alleviating the temperature rise problem during the operation of the actuating assembly 3. The hollow groove 2143 absorbs high-frequency vibration energy by adjusting the local stiffness, reduces the resonance risk, reduces the influence of inertia on the high-frequency dynamic response, and ensures the actuation accuracy. The platform section of the second sub-mounting body 2142 provides a stable anchor point for the elastic member. Combining with the flexible deformation ability of the hollow groove 2143, it can compensate for the small displacement caused by temperature or assembly errors, and maintain the close fit between the first rolling element 222 and the sliding groove 12.

[0046] Please refer to Figure 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 element 222, ensuring the precise positioning of the rolling element 22 along a preset direction, reducing the offset caused by force-induced deformation. The first elastic member 23 applies a controllable pre-tightening force through the second mounting structure 24, so that the first rolling element 222 is always in close contact with the contact surface, avoiding vibration or accuracy loss caused by gaps. The second mounting structure 24 is a rigid reference. The first elastic member 23 provides a flexible connection, which can reduce direct friction impact through the rigid part and absorb mechanical stress through the elastic member, thereby reducing the wear risk of the contact between the first rolling element 222 and the sliding groove 12.

[0047] Please refer to Figure 4, in some embodiments, the first elastic member 23 includes a first recess 231 and a second recess 232. The recessed directions of the first recess 231 and the second recess 232 are opposite. The first recess 231 is provided at both ends of the second recess 232 along the first direction. The middle part of the first recess 231 contacts the second side surface 213. The first recess 231 includes a first end and a second end along the first direction. Both the first end and the second end are spaced apart from the second side surface 213 along the second direction. The first end is connected to the first mounting structure 214, and the second end is connected to the second recess 232. The second recess 232 is spaced apart from the second side surface 213 along the second direction. The middle part of the second recess 232 is rotatably connected to the first rolling body 222. The design that the recessed directions of the first recess 231 and the second recess 232 are opposite enables the first elastic member 23 to deform in different directions when being compressed or stretched. For example, when the first recess 231 is compressed, it contracts in the recessed direction, while the second recess 232 may deform in the opposite direction, thereby dispersing stress concentration. This structure avoids the problem of excessive local stress caused by unidirectional deformation of traditional single-recess elastic members and extends the service life of the first elastic member 23. The two ends of the first recess 231 are respectively connected to the first mounting structure 214 and the second recess 232, forming a flexible support structure with both ends fixed and the middle suspended. When the first rolling body 222 is acted upon by an external force, the middle part of the second recess 232 can undergo elastic deformation to provide a pre-tightening force along the first direction. At the same time, the spaced design between the first recess 231 and the second side surface 213 allows it to have a small displacement in the second direction, adaptively adjusting the contact pressure. This design can dynamically compensate for assembly errors or thermal expansion / vibration offsets during operation, ensuring a constant contact between the first rolling body 222 and the sliding groove 12. The alternating recessed structure of the first recess 231 and the second recess 232 increases the effective deformation path length of the first elastic member 23. When high-frequency vibration is transmitted to the elastic member, the energy needs to be gradually absorbed in multiple bending paths, achieving more efficient high-frequency damping. This reduces the amplitude of vibration energy transmitted to the base body 21 and reduces the risk of resonance. The middle part of the first recess 231 contacts the second side surface 213 to form a rigid fulcrum, while the middle part of the second recess 232 is connected to the first rolling body 222 to form a flexible connection point. In this way, the deformation of the elastic member is mainly restricted in the first direction, suppressing unnecessary vibration modes perpendicular to the movement direction (such as the second direction or the third direction, and the third direction is the thickness direction of the actuating assembly 3). For example, when the first rolling body 222 is subjected to a lateral force, the deformation of the second recess 232 is restricted by the fixed end of the first recess 231, avoiding multi-axis coupled vibration. The double-recess structure realizes a larger effective elastic stroke in a limited space, enabling the first elastic member 23 to have a higher energy storage density than a traditional linear spring under the same volume, which is beneficial to the miniaturized design of the motor stator 10.

[0048] The base assembly 2 of the present application includes a base body 21, a first elastic member 23, a first rolling body 221, and a first rolling body 222. With such a setting, after the piezoelectric ultrasonic actuator 31 deforms, it can not only provide sufficient clamping force but also retain its vibration mode to the greatest extent, thereby minimizing energy loss.

[0049] Please refer to Figure 2 , in some embodiments, the motor stator 10 further includes a second elastic member 25. The second elastic member 25 is located in the moving cavity 11, and the two ends of the second elastic member 25 in the first direction are respectively connected to the outer wall of the base assembly 2 and the cavity wall of the moving cavity 11. Adding the second elastic member 25 plays a role in buffering and providing a pre-tightening force between the base assembly 2 and the housing 1. In terms of buffering, the second elastic member 25 can reduce the adverse effects caused by external vibrations, impacts, etc. during the operation of the base assembly 2 and protect the internal actuation assembly 3; in terms of pre-tightening force, the second elastic member 25 ensures a reasonable contact state between the output driving foot 32 and the mover, maintains the stability and accuracy of the mechanism operation, and ensures the normal operation of the piezoelectric motor 100. In addition, by adjusting the pre-tightening force of the second elastic member 25, the output performance of the piezoelectric motor 100 can also be changed, thereby improving the motion characteristics of the motor.

[0050] In an alternative embodiment, one end of the second elastic member 25 in the first direction is connected to the side wall of the base body 21 opposite to its moving port, and the other end is connected to the cavity wall of the housing 1.

[0051] Please refer to Figure 2 , in some embodiments, both the base assembly 2 and the actuation assembly 3 include two. The actuation assemblies 3 are respectively connected to one base assembly 2, and the two base assemblies 2 are stacked and spaced along the thickness direction of the actuation assembly 3. In other words, two base assemblies 2 and actuation assemblies 3 of the same specification are arranged in the moving cavity 11 of the housing 1 to achieve the effect of multi-foot drive, making the overall structure of the motor stator 10 compact and functional.

[0052] It should be noted that, in order to ensure the accuracy of the operating position of the piezoelectric ultrasonic actuator 31 during deformation, the base assembly 2 is designed to fix the piezoelectric ultrasonic actuator 31. This design not only simplifies the overall structure, but also makes the assembly of the motor stator 10 more convenient, while ensuring the transmission accuracy 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. Generally, as the number of driving feet increases, the number of signal channels to be controlled will also increase accordingly. However, in the present invention, two identical base assemblies 2 and actuator assemblies 3 are adopted. By simultaneously exciting the same partitions of the ceramic layers of the two piezoelectric ultrasonic actuators 31, the ceramic layers generate the same deformation, so that it can be ensured that even if the number of driving feet increases, the piezoelectric motor 100 still only requires two channels to achieve driving. While ensuring an increase in the output force of the motor, the complexity of control is simplified.

[0053] Please refer to Figure 7 , in a second aspect, an embodiment of the present application provides a piezoelectric motor 100, which includes a motor stator 10 and a motor rotor 20. The motor stator 10 is drivingly connected to the motor rotor 20 along 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.

[0054] Please refer to Figure 6 , in some embodiments, the piezoelectric motor 100 further includes a friction member 30. The friction member 30 is connected to the motor rotor 20 and is disposed between the motor stator 10 and the motor rotor 20 along the first direction. The friction member 30 is used to contact the output driving feet 32 of the motor stator 10. The periodic elliptical motion trajectory friction generated by the output driving feet 32 of the motor stator 10 transfers vibration energy to the friction member 30. Under high-frequency vibration, the surface particles of the motor stator 10 periodically contact the friction member 30 to form an impact-slip motion, thereby driving the motor rotor 20.

[0055] In an alternative embodiment, the friction member 30 is a ceramic friction strip.

[0056] Please refer to Figure 6 , in some embodiments, the piezoelectric motor 100 further includes a motor base 40. The motor rotor 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. By providing the motor base 40, both the motor rotor 20 and the motor stator 10 are mounted on the electrode base, which can ensure the relative positions of the motor rotor 20 and the motor stator 10 and guarantee the operating accuracy of the piezoelectric motor 100.

[0057] Please refer to Figure 5In some embodiments, the motor base 40 is provided with a movable groove 401 along the first direction, the motor mover 20 is located outside the movable groove 401, and the piezoelectric motor 100 further includes a sliding assembly 402 and a positioning fastener, the sliding assembly 402 is arranged in the movable groove 401, the sliding assembly 402 is connected to the bottom wall of the movable groove 401, the motor stator 10 is connected to the sliding assembly 402, one end of the positioning fastener along the first direction is connected to the side wall of the movable groove 401, and the other end abuts against the motor stator 10, and the positioning fastener is used to adjust the position of the motor stator 10 along the first direction. The motor stator 10 is fixed as a whole in the movable groove 401 of the motor base 40, and the motor stator 10 is fixed by the sliding assembly 402 to prevent the motor stator 10 from deflecting in the first direction, to ensure that the friction member 30 of the motor mover 20 and the output driving foot 32 of the motor stator 10 can be fully in contact, and to ensure the running accuracy of the motor. The positioning fastener enables the motor stator 10 to achieve adjustable pre-pressure. The rear end of the housing 1 of the motor stator 10 away from the motor mover 20 along the first direction is fixed by the positioning fastener. The pre-pressure between the friction member 30 of the motor stator 10 and the motor mover 20 is adjusted by rotating the positioning fastener to ensure stable contact between the motor stator 10 and the motor mover 20.

[0058] See also Figure 5 In some embodiments, the sliding assembly 402 includes a sliding rail 4021 and a slider 4022 that are slidably connected, the sliding rail 4021 is connected to the bottom wall of the movable groove 401, and the slider 4022 is connected to the motor stator 10. The sliding assembly 402 is provided with the sliding rail 4021 and the slider 4022, which can prevent the motor stator 10 from deflecting in the first direction and the second direction, ensure that the friction member 30 of the motor mover 20 and the output driving foot 32 of the motor stator 10 can be fully in contact, and ensure the operating accuracy of the piezoelectric motor 100.

[0059] The specific working principle of the motor stator 10 of the embodiment of the present application will be introduced below: Based on the synthesis principle of longitudinal vibration and bending vibration, under the condition that the influence of the interference mode of the motor stator 10 on the working mode is ignored, a high-frequency voltage excitation signal with a phase difference of 90° is applied to the two diagonal sides of the motor stator 10 respectively, then the first-order longitudinal vibration modal response and the second-order bending vibration modal response of the motor stator 10 will be excited at the same time. It can be seen that there is a phase difference in time between the first-order longitudinal vibration displacement response and the second-order bending vibration displacement response of the motor stator 10. 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 peak and the trough, which indicates that there is also a phase difference in space. That is, when the bending vibration of the motor stator 10 reaches the amplitude, its longitudinal elongation reaches the maximum, and then it can realize an elliptical motion trajectory at the output drive foot 32.

[0060] When the motor stator 10 is Figure 8The maximum bending deformation position shown in (a) gradually changes to the maximum elongation position shown in Figure 8 (b). During this change process, the motor stator 10 starts from the maximum position of bending vibration, and as it elongates longitudinally, it moves to the equilibrium position of bending vibration and contacts the motor rotor 20. Relying on friction, the motor stator 10 drives the motor rotor 20 to move one step to the right, and the output driving foot 32 rotates around the z-axis towards the negative x-axis and the positive y-axis. At this stage, the output driving foot 32 always remains in contact with the motor rotor 20.

[0061] When the motor stator 10 moves from Figure 8 the maximum elongation position shown in (b) to Figure 8 the maximum bending deformation position shown in (c), but the bending direction is opposite to that in Figure 8 (a). During this change process, the motor stator 10 moves from the maximum position of longitudinal elongation to the maximum position of reverse bending deformation, and continuously contacts the motor rotor 20 during this period. With the help of friction, the motor stator 10 continuously drives the motor rotor 20 to move to the right, and the output driving foot 32 rotates around the z-axis towards the positive x-axis and the positive y-axis. At this stage, the output driving foot 32 still remains in contact with the motor rotor 20.

[0062] When the motor stator 10 moves from Figure 8 the reverse maximum bending deformation position shown in (c) to Figure 8 the shortest longitudinal elongation position shown in (d). During this change process, the motor stator 10 moves from the maximum position of reverse bending deformation to the limit position of longitudinal expansion and contraction. During this driving process, the output driving foot 32 separates from the motor rotor 20, and the output driving foot 32 rotates around the z-axis towards the positive x-axis and the negative y-axis.

[0063] When the motor stator 10 moves from Figure 8 the shortest longitudinal expansion and contraction position shown in (d) to Figure 8 the maximum bending deformation limit position shown in (a). During this change period, the motor rotor 20 moves from the limit position of longitudinal expansion and contraction to the maximum position of bending deformation. Throughout the process, the output driving foot 32 always remains separated from the motor rotor 20, and the output driving foot 32 rotates around the z-axis towards the negative x-axis and the negative y-axis.

[0064] As can be seen from the above four steps, the output driving foot 32 of the motor stator 10 will complete an elliptical motion within one cycle. Therefore, when a certain pre-pressure is applied, the output driving foot 32 of the motor stator 10 can be closely attached to the motor rotor 20. At this time, relying on the frictional force generated between the motor stator 10 and the friction member 30, the motor rotor 20 can be pushed to move linearly. Similarly, when the driving voltage signal is changed, the motion trajectory of the motor stator 10 will also reverse, thereby enabling the motor rotor 20 to achieve reverse motion.

[0065] It should be noted that the current piezoelectric motors have the following problems:

[0066] The assembly of multiple components reduces the reliability of the motor; in order to improve the output performance of the piezoelectric motor, the method of increasing the number of driving feet is usually adopted. Although this method can effectively increase the output force of the motor, it will make the motor structure more complex and increase the design difficulty; secondly, higher precision is required during assembly to ensure that each driving foot can work together, which puts higher requirements on assembly; in addition, more driving feet may also introduce additional vibration mode interference, affecting the stability and energy transfer efficiency of the motor.

[0067] The reduction in output efficiency caused by optimizing the motor structure: In order to better excite the working mode of the motor stator, the ultrasonic motor with multi-foot driving usually adopts the design method of slotting the elastic body. However, this design fails to fully consider the matching of the motion between the rotor and the stator, resulting in significant energy transfer losses during operation, thereby reducing the vibration energy transfer efficiency.

[0068] Driving at ultrasonic frequencies makes it difficult to ensure the accuracy of the motor: The friction coefficient, pre-tightening force, and contact area are key parameters to ensure the energy transfer efficiency. However, the motor stator structure often undergoes small deformations due to insufficient rigidity under high-frequency vibrations, and uneven pre-tightening force distribution will generate small lateral forces; in addition, the ultrasonic friction reduction phenomenon that occurs in the driving foot under high-frequency driving; and the thermal expansion of the material caused by temperature rise will also change the contact area. These factors together lead to positioning deviation, thereby reducing the motion accuracy and making it difficult for the motor to meet the nanometer-level requirements.

[0069] The complex control problem caused by multi-foot driving: In a multi-foot ultrasonic motor, multiple piezoelectric ceramic driving units need to work together to achieve the motion of the stator. Usually, each driving unit requires an independent signal channel, and the signals must maintain an accurate phase difference to generate the required vibration mode. In addition, since the operating frequency of the ultrasonic motor is relatively high (usually above 20 kHz), the circuit needs to have high-frequency signal processing capabilities. Therefore, the circuit design and debugging of multi-foot ultrasonic motors are often more complex.

[0070] The complexity of the structure is mainly reflected in the design difficulty, assembly precision requirements, and vibration mode interference caused by the increase in the number of driving feet. The complexity of control is reflected in the independent signal channels, precise phase difference control, and high-frequency signal processing capabilities required for the coordinated operation of multiple driving units. To solve these problems, it is necessary to optimize the layout and assembly process of the driving feet in the structural design, and at the same time improve the precision and efficiency of signal processing in the control system to achieve a balance between motor performance and complexity.

[0071] In the embodiment of the present application, the housing 1, the base assembly 2, and the actuating assembly 3 are regarded as an independent module, which has standardized positioning and dimensions to ensure their interchangeability and flexible combination. Necessary support and fixing structures are integrated inside the module to reduce the dependence on external components, which not only reduces the assembly difficulty and simplifies the assembly process, but also improves the assembly precision. Inside the motor stator 10, two piezoelectric ultrasonic actuators 31 are independently assembled and debugged. If a certain piezoelectric ultrasonic actuator 31 fails, it can be detected and replaced separately, improving the maintenance and repair efficiency. The motor base 40 has a guiding effect on the motor stator 10 in the first direction and the second direction by opening a movable slot 401. In addition, the unique design of the base assembly 2 not only fixes the piezoelectric ultrasonic actuator 31, but also maximally retains its deformation ability, enabling the energy generated by the deformation of the piezoelectric ultrasonic actuator 31 to be more efficiently transmitted to the output driving foot 32. This design not only reduces energy loss, but also significantly improves the operating efficiency of the motor. The pre-pressure of the motor stator 10 is adjusted by a positioning fastener to realize the speed regulation of the motor. The piezoelectric motor 100 of the embodiment of the present application avoids the energy loss caused by slotting and reduces the processing complexity at the same time. The motor stator 10 changes the traditional patch structure and adopts the method of piezoelectric stacking, solving the problem of the increase in the number of channels caused by the increase in the number of driving feet. This method makes the number of channels independent of the number of driving feet. Even if the number of driving feet is increased, only two channels are still required to achieve driving, simplifying the control difficulty while increasing the output force.

[0072] In the description of the present application, it should be understood that if terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, the orientation or positional relationship indicated by these terms is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present application.

[0073] In addition, if the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of this application, if the term "a plurality of" appears, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0074] In this application, unless otherwise clearly specified and limited, if terms such as "installed", "connected", "joined", "fixed", etc. appear, these terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements or the interaction relationship between two elements, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0075] In this application, unless otherwise clearly specified and limited, if there is a description such as a first feature being "on" or "under" a second feature, the meaning can be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature can mean that the first feature is directly above or obliquely above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. The first feature being "under", "beneath" and "underneath" the second feature can be that the first feature is directly below or obliquely below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0076] It should be noted that if an element is referred to as "fixed to" or "disposed on" another element, it can be directly on the other element or there can also be an intermediate element. If an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. If so, the terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used in this application are only for the purpose of illustration and do not represent the only implementation.

[0077] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity in description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered to be within the scope described in this specification.

[0078] The above-described embodiments merely represent several implementation manners of the present application. The description thereof is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all fall within the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the appended claims.

Claims

1. A motor stator, characterized in that, Comprising: A housing provided with an activity cavity; A base assembly movably connected to the cavity wall of the activity cavity; An actuating assembly connected to the base assembly, the actuating assembly being configured to drive the base assembly to move relative to the housing in a first direction, the first direction intersecting the thickness direction of the actuating assembly.

2. The motor stator according to claim 1, characterized in that The base assembly includes a base body and rolling elements, the actuating assembly is connected to the base body, the rolling elements are rotatably connected to the base body, the cavity wall of the activity cavity is recessed with a chute, and the rolling elements are slidably disposed in the chute.

3. The stator of the motor according to claim 2, wherein The base assembly further includes a first elastic member, the rolling elements include a first rolling element and a second rolling element, the base body includes a first side surface and a second side surface oppositely disposed along a second direction, the first rolling element is rotatably connected to the first side surface, two ends of the first elastic member in the first direction are connected to the second side surface, the second rolling element is rotatably connected to the first elastic member, the second direction intersects the first direction and the thickness direction of the actuating assembly pairwise, and the three are not coplanar.

4. The motor stator according to claim 1, wherein, The motor stator further includes a second elastic member, the second elastic member is located in the activity cavity, and two ends of the second elastic member in the first direction are respectively connected to the outer wall of the base assembly and the cavity wall of the activity cavity.

5. The stator of an electric machine according to claim 1, characterized in that, The actuating assembly includes a piezoelectric ultrasonic actuator and an output driving foot, the piezoelectric ultrasonic actuator is connected to the base assembly, the output driving foot is connected to one end of the piezoelectric ultrasonic actuator in the first direction, and the piezoelectric ultrasonic actuator is configured to drive the base assembly to move in the first direction so that the output driving foot moves relative to the housing.

6. The stator of an electric machine according to claim 1, characterized in that, Both the base assembly and the actuating assembly include two, the actuating assemblies are respectively connected to one base assembly, and the two base assemblies are stacked and spaced apart along the thickness direction of the actuating assembly.

7. A piezoelectric motor, characterized in that, The piezoelectric motor includes a motor stator and a motor rotor, the motor stator is drivingly connected to the motor rotor in a first direction, and the motor stator is the motor stator according to any one of claims 1 to 6.

8. The piezoelectric motor according to claim 7, characterized in that, The piezoelectric motor further includes a friction member, the friction member is connected to the motor rotor and is disposed between the motor stator and the motor rotor along the first direction.

9. The piezoelectric motor according to claim 7, characterized in that, The piezoelectric motor further includes a motor base, the motor rotor is disposed on the motor base, and the motor stator is movably connected to the motor base in the first direction.

10. The piezoelectric motor according to claim 9, characterized in that, The motor base is recessed with an activity groove along the first direction, the motor rotor is located outside the activity groove, the piezoelectric motor further includes a sliding assembly and an adjustment fastener, the sliding assembly is disposed in the activity groove, the sliding assembly is connected to the bottom wall of the activity groove, the motor stator is connected to the sliding assembly, and one end of the adjustment fastener in the first direction is connected to the side wall of the activity groove and the other end abuts against the motor stator, and the adjustment fastener is used to adjust the position of the motor stator in the first direction.

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