CN110635711A

CN110635711A - Nano displacement linear stepping motor

Info

Publication number: CN110635711A
Application number: CN201910602746.2A
Authority: CN
Inventors: 杨晓峰; 王振华; 康华洲; 郝凌凌; 陈庆生
Original assignee: Ji Hua Laboratory
Current assignee: Ji Hua Laboratory
Priority date: 2019-07-05
Filing date: 2019-07-05
Publication date: 2019-12-31

Abstract

The invention discloses a nanometer displacement linear stepping motor which comprises a motor shell, a motor rotor, at least one pair of first piezoelectric ceramic drivers and at least one pair of second piezoelectric ceramic drivers. The motor rotor is arranged in the motor shell, the at least one pair of first piezoelectric ceramic drivers are symmetrically arranged relative to the motor rotor and are arranged on the motor shell, and the at least one pair of second piezoelectric ceramic drivers are symmetrically arranged relative to the motor rotor and are arranged on the motor shell. The top ends of at least one pair of first piezoelectric ceramic drivers are contacted with the motor rotor so as to provide at least axial acting force and axial displacement, and the top ends of at least one pair of second piezoelectric ceramic drivers are contacted with the motor rotor so as to provide at least radial acting force and radial displacement. The nanometer displacement linear stepping motor has the advantages of simple structure and high precision.

Description

Nano displacement linear stepping motor

Technical Field

The invention relates to the field of integrated circuit equipment manufacturing, in particular to a nanometer displacement linear stepping motor.

Background

In recent years, with the increasing integration of large-scale integrated circuit devices, the precision requirement of the workpiece stage is increasing, and especially the motion precision of the modules such as the regulation and control of the stage and the objective lens in the lithography machine and the film thickness detection, the motion stroke is increasing year by year with the increasing requirement of the workpiece stage. The displacement driving technology is also continuously improved, so that the piezoelectric ceramic micro-displacement driver is widely applied. At present, the main ways in precision driving are: mechanical lead screws, linear motors and piezoceramic actuators, while in displacement drives of the nanometer scale mainly piezoceramic drivers.

The combination of a plurality of thickness displacement stacks is adopted in a certain patent to form pressurization and driving actions on the rotor, and the structure is complex, the manufacturing cost is high, the manufacturing process is complex, and commercialization is not easy.

In a certain patent, the central shaft is driven to move in a stepping manner by the combination of four groups of thickness displacement stacks and axial displacement stacks, the process of the axial piezoelectric stacks in the manufacturing process is complex, organic colloid is required for bonding, the bonding cannot be realized by a co-firing process, and due to the existence of the organic colloid, the piezoelectric driver is easy to lose efficacy in the time aging resistance and severe temperature and illumination environments.

At present, piezoelectric ceramic linear motors are mainly applied to companies such as PI and PM, and the axial displacement is mainly provided by using piezoelectric ceramic sheets axially polarized by piezoelectric ceramics, so that the axial displacement ceramic sheets are manufactured firstly, and then the ceramic sheets are bonded by an organic adhesive layer, so that the manufacturing process is complex, the characteristics of light resistance and temperature aging resistance of the axial piezoelectric ceramic sheets are limited due to the existence of the organic adhesive layer, and the characteristics that the axial piezoelectric ceramic sheets cannot be recovered after the characteristics of the piezoelectric ceramics are degraded also cause the limitation of the use of the piezoelectric ceramic motors.

Disclosure of Invention

The invention aims to provide a nano-displacement linear stepping motor to solve the problems in the prior art.

In order to solve the above-mentioned problems, according to an aspect of the present invention, there is provided a nano-displacement linear stepping motor, characterized in that the nano-displacement linear stepping motor comprises a motor housing, a motor mover, at least one pair of first piezoelectric ceramic drivers and at least one pair of second piezoelectric ceramic drivers,

the motor rotor is arranged in the motor shell,

the at least one pair of first piezoceramic drivers are symmetrically arranged around the motor rotor and are mounted on the motor housing,

the at least one pair of second piezoceramic drivers are symmetrically arranged around the motor rotor and are mounted on the motor housing,

the top ends of the at least one pair of first piezoceramic drivers are in contact with the motor rotor so as to provide at least axial acting force and axial displacement, and the top ends of the at least one pair of second piezoceramic drivers are in contact with the motor rotor so as to provide at least radial acting force and radial displacement.

In one embodiment, the first piezoceramic driver comprises a bending displacement stack and a swing arm, the bending displacement stack is formed by stacking a plurality of piezoceramic wafers or is directly manufactured by a multilayer co-firing process, wherein the surfaces of the piezoceramic wafers of the bending displacement stack are covered with spaced electrode layers so as to form a first group of electrode layers and a second group of electrode layers.

In one embodiment, in operation, the first group of electrode layers is powered to make the bending displacement stack form an angular bend, then the second group of electrode layers is powered to make the bending displacement stack restore to a vertical state, and then the voltage of the first group of electrode layers or the second group of electrode layers is reduced to zero to make the bending displacement stack form an angular bend again, so that the mover swings back and forth or moves in the same direction, wherein the swing arm is used for amplifying the displacement of the bending displacement stack.

In one embodiment, the first piezoelectric ceramic displacement driver further comprises a thickness displacement stack, the thickness displacement stack is formed by stacking a plurality of piezoelectric ceramic sheets or is directly manufactured through a multilayer co-firing process, and the surface of the piezoelectric ceramic sheet of the thickness displacement stack is covered with a full electrode layer, so that the first piezoelectric ceramic driver can also provide radial acting force and radial displacement.

In one embodiment, the second piezoelectric ceramic displacement driver comprises a thickness displacement stack and a swing arm, the thickness displacement stack is formed by stacking a plurality of piezoelectric ceramic sheets or is directly manufactured through a multilayer co-firing process, and the surface of each piezoelectric ceramic sheet of the thickness displacement stack is covered with a full electrode layer, so that the second piezoelectric ceramic driver can provide radial acting force and radial displacement.

In one embodiment, the second piezo-ceramic displacement driver further comprises a bending displacement stack mounted between the thickness displacement stack and the swing arm, such that the second piezo-ceramic displacement driver is also capable of providing axial force and axial displacement.

In one embodiment, the nano-displacement linear stepper motor includes two pairs of first piezo ceramic drivers and two pairs of second piezo ceramic drivers, the two pairs of first piezo ceramic drivers and the two pairs of second piezo ceramic drivers being aligned in a column.

In one embodiment, the nano-displacement linear stepper motor includes two pairs of first piezo ceramic drivers and two pairs of second piezo ceramic drivers, the two pairs of first piezo ceramic drivers aligned in one column and the two pairs of second piezo ceramic drivers aligned in another column.

In one embodiment, one end of the swing arm is in contact with the mover, and the other end of the swing arm is in contact with the bending displacement stack or a thickness displacement stack for separating the swing arm from the mover when the mover is not operated, and for bringing the swing arm into contact with the mover and applying pressure when the mover is operated.

In one embodiment, one end of the thickness displacement stack is connected to the bend displacement stack and the other end of the thickness displacement stack is connected to the swing arm.

In one embodiment, one end of the bend displacement stack is connected to the thickness displacement stack and the other end of the bend displacement stack is connected to the swing arm.

In one embodiment, one end of the swing arm is connected to the thickness displacement stack and the other end of the swing arm is connected to the bend displacement stack.

In one embodiment, the piezoceramic displacement driver comprises a plurality of the bending displacement stacks and/or a plurality of the thickness displacement stacks.

In one embodiment, the thickness displacement stack and the bend displacement stack are co-fired stacks, and/or the thickness displacement stack and the bend displacement stack are organic adhesive bonded stacks, and/or the thickness displacement stack and the bend displacement stack are stacks formed by a glass frit sintering process.

In one embodiment, the connection between the thickness displacement stack, the bend displacement stack and the swing arm is a co-fired connection, and/or an organic adhesive bonded connection, and/or a glass paste sintering process connection.

In one embodiment, the cross-sectional shape of the swing arm is rectangular, triangular, hemispherical, inverted T-shaped and/or the bottom surface of the swing arm is square and the top is arc-shaped, hemispherical and/or inverted T-shaped;

in one embodiment, the electrode layers of the thickness displacement stack are fully electrode or the edge of the electrode layers are spaced between 0-1mm from the ceramic edge;

in one embodiment, the electrode layer of the bend displacement stack is comprised of two or more divided electrodes, wherein the distance gap between the electrodes in the two parts is between 0.1mm and 2 mm;

in one embodiment, the length of the side of the section of the piezoelectric ceramic displacement driver is in a range of 1mm-50 mm;

in one embodiment, the thickness-displacement stack has a height between 0.1mm and 100 mm;

in one embodiment, the height of the curved stack may be between 0.1mm-100 mm;

in one embodiment, the height of the swing arm is between 0.1mm and 100 mm.

According to another aspect of the present invention, there is provided a nano-displacement linear stepping motor, including a motor housing, a motor mover, at least one pair of first piezoelectric ceramic drivers, a guide rail and a slider, wherein one side of the motor mover is mounted at the top of the motor housing through the guide rail and the slider, the at least one pair of first piezoelectric ceramic drivers are mounted side by side at the bottom of the motor housing, and the top of the first piezoelectric ceramic drivers is in contact with the motor mover and provides at least an axial acting force and an axial displacement.

According to another aspect of the present invention, there is provided a nano-displacement linear stepping motor including a motor housing, a motor mover, at least one pair of first piezoelectric ceramic drivers, and at least one pair of second piezoelectric ceramic drivers,

the motor rotor is arranged in the motor shell,

the at least one pair of first piezoceramic drivers are symmetrically arranged about the motor mover and mounted on the motor mover,

the at least one pair of second piezoceramic drivers are symmetrically arranged about the motor mover and mounted on the motor mover,

the top ends of the at least one pair of first piezoceramic drivers are in contact with the motor housing so as to provide at least an axial force and an axial displacement,

the top ends of the at least one pair of second piezoceramic drivers are in contact with the motor housing to provide at least a radial force and a radial displacement.

The invention realizes the high-precision displacement of the piezoelectric ceramic motor, enables the piezoelectric ceramic motor to have high driving acting force, solves the problems of environmental characteristics such as illumination resistance, temperature aging and the like of the piezoelectric ceramic motor in the prior art, and solves the problem that the axial displacement stack of the piezoelectric ceramic stepping motor in the prior art can not recover the electrical property after the performance is degraded.

Drawings

Fig. 1 is a schematic structural diagram of a high-precision nano-displacement linear stepping motor according to an embodiment of the present invention.

Fig. 2 is a schematic cross-sectional view of a high precision piezoceramic displacement actuator according to a first embodiment of the present invention.

Figures 3a-d show schematic diagrams of the action of the piezoceramic displacement actuator of figure 2.

Fig. 4a-d are schematic diagrams of the polarization directions of the electrode layers and the electric field application states of the piezoelectric ceramic displacement driver of fig. 2.

Fig. 5 is a schematic structural diagram of a piezoceramic displacement actuator according to a second embodiment of the present invention.

Fig. 6 is a schematic structural view of a piezoceramic displacement actuator according to a third embodiment of the present invention.

Fig. 7 is a schematic illustration of an electrode structure of the electrode layers of the bend displacement stack of fig. 5.

Fig. 8 is a schematic structural view of a piezoceramic displacement actuator according to a fourth embodiment of the present invention.

Fig. 9 is a schematic structural view of a piezoelectric ceramic displacement actuator according to a fifth embodiment of the present invention.

Fig. 10 is a schematic structural view of a first piezoceramic displacement actuator of the present invention.

Fig. 11 is a schematic structural view of a second piezoceramic displacement actuator according to the present invention.

Fig. 12a to 12f illustrate the movement of the high-precision nano-displacement linear stepping motor according to an embodiment of the present invention.

Fig. 13a-13h illustrate the movement of a high precision nano-displacement linear stepper motor according to another embodiment.

Fig. 14 is a schematic structural view showing a nano-displacement linear stepping motor according to another embodiment.

Fig. 15a-b are schematic structural views illustrating a nano-displacement linear stepping motor according to another embodiment, wherein fig. 15b is a side view of fig. 15 a.

Fig. 16 is a schematic structural view showing a nano-displacement linear stepping motor according to another embodiment, wherein fig. 15b is a side view of fig. 15a,

fig. 17 is a schematic structural view showing a nano-displacement linear stepping motor according to another embodiment.

Detailed Description

The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings so that the objects, features and advantages of the invention can be more clearly understood. It should be understood that the embodiments shown in the drawings are not intended to limit the scope of the present invention, but are merely intended to illustrate the spirit of the technical solution of the present invention.

In the following description, for the purposes of illustrating various disclosed embodiments, certain specific details are set forth in order to provide a thorough understanding of the various disclosed embodiments. One skilled in the relevant art will recognize, however, that the embodiments may be practiced without one or more of the specific details. In other instances, well-known devices, structures and techniques associated with this application may not be shown or described in detail to avoid unnecessarily obscuring the description of the embodiments.

Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

In the following description, for the purposes of clearly illustrating the structure and operation of the present invention, directional terms will be used, but terms such as "front", "rear", "left", "right", "outer", "inner", "outer", "inward", "upper", "lower", etc. should be construed as words of convenience and should not be construed as limiting terms.

According to one aspect of the invention, the problems that the existing piezoelectric ceramic stepping motor is complex in structure and difficult to realize commercial use, or the manufacturing process is complex and high in cost can be solved. According to another aspect of the invention, the problem that the axial displacement stack of the existing piezoelectric ceramic stepper motor is bonded by organic colloid, so that the service life of the motor is short in resisting environmental characteristics such as illumination resistance, temperature aging resistance and the like of the organic colloid is solved. According to another aspect of the invention, the problem that the existing piezoelectric ceramic stepper motor axial displacement stack cannot recover the electrical performance by power-up after the performance is depolarized can be solved. According to another aspect of the invention, the problem that the piezoelectric ceramic axial displacement is driven by low voltage to form a large stroke in the prior art can be solved.

The invention relates to a nano-displacement linear stepping motor, which comprises a motor shell, a motor rotor, at least one pair of first piezoelectric ceramic drivers and at least one pair of second piezoelectric ceramic drivers. The motor rotor is arranged in the motor shell, and the at least one pair of first piezoelectric ceramic drivers are symmetrically arranged around the motor rotor and are arranged on the motor shell. And at least one pair of second piezoelectric ceramic drivers are symmetrically arranged relative to the motor rotor and are arranged on the motor shell. The top ends of at least one pair of first piezoelectric ceramic drivers are contacted with the motor rotor so as to provide at least axial acting force and axial displacement. The top ends of at least one pair of second piezoceramic drivers are in contact with the motor rotor so as to provide at least radial acting force and radial displacement.

In one embodiment, the first piezoceramic driver includes a bending displacement stack and a swing arm. The bending displacement stack is formed by stacking a plurality of piezoelectric ceramic plates or directly manufactured by a multilayer co-firing process. The surfaces of the piezoceramic wafers of the bend displacement stack are covered with spaced apart electrode layers to form a first set of electrode layers and a second set of electrode layers. When the bending displacement stacking device operates, the first group of electrode layers are electrified to enable the bending displacement stacking to form bending at a certain angle, then the second group of electrode layers are electrified to enable the bending displacement stacking to restore to a vertical state, the voltage of the first group of electrode layers or the second group of electrode layers is reduced to zero, and the bending displacement stacking is enabled to form bending at a certain angle again, so that the mover can swing back and forth or move towards the same direction. The swing arm is used for amplifying the displacement of the bending displacement stack.

Exemplary embodiments of the nano-displacement linear stepping motor according to the present invention will be described in detail below with reference to the accompanying drawings.

Example 1

Fig. 1 is a schematic structural diagram of a high-precision nano-displacement linear stepping motor according to an embodiment of the present invention. As shown in fig. 1, the nano-displacement linear stepping motor 100 includes a motor housing 10, a motor mover 20, at least one pair of first piezoelectric ceramic drivers 30, and at least one pair of second piezoelectric ceramic drivers 40. The motor mover 20 is mounted in the motor housing 10, and at least one pair of first piezoceramic drivers 30 is symmetrically arranged with respect to the motor mover 20 and mounted on the motor housing 10. At least one pair of second piezoceramic drivers 40 is arranged symmetrically about the motor mover 20 and mounted on the motor housing 10. The tips of at least one pair of first piezo ceramic drivers 30 are in contact with the motor mover 20 to provide at least an axial force and an axial displacement. The tips of at least one pair of second piezo ceramic drivers 40 contact the motor mover 20 to provide at least a radial force and a radial displacement.

The following describes in detail various piezoelectric ceramic drivers (which may be the first piezoelectric ceramic driver or the second piezoelectric ceramic driver) of the high-precision nano-displacement linear stepper motor according to the present invention with reference to fig. 2 to 9.

Fig. 2 is a schematic cross-sectional view of a high precision piezoceramic displacement actuator according to a first embodiment of the present invention. Fig. 3a-d are schematic views showing the operation of the piezoelectric ceramic displacement actuator of fig. 2, and fig. 4a-d are schematic views showing the polarization directions of electrode layers and the electric field application states of the piezoelectric ceramic displacement actuator of fig. 2. As shown in fig. 2-4, the piezoceramic displacement driver includes a thickness displacement stack 101, a bending displacement stack 102, and a swing arm 103. Wherein the thickness displacement stack 101 is coupled to the base 300 and the swing arm 103 contacts the mover 200. The thickness displacement stack is formed by 10 layers of 0.5mm thick piezoelectric ceramic plates 106, the upper and lower surfaces of which are covered with full electrode layers 107, and the polarization directions of two adjacent piezoelectric ceramic plates 106 are opposite, as shown in fig. 4a-4 d.

The bending displacement stack 102 is formed by stacking 10 piezoelectric ceramic sheets 106 with a thickness of 0.5mm, the upper and lower surfaces of each piezoelectric ceramic sheet are covered by dividing electrodes 108a and 108b, the two electrodes 108a and 108b of the same piezoelectric ceramic sheet have the same polarization direction, and the polarization directions of the two adjacent piezoelectric ceramic sheets are opposite, as shown in fig. 4a-4d, a certain gap is formed between the dividing electrodes 108a and 108b, and the gap distance may be, for example, 1 mm. The bottom surface of the swing arm 103 is square, the side length is 10mm, and the height of the swing arm 103 is 5arctan60 degrees.

In the first embodiment of the piezoceramic displacement actuator of the present invention, the initial state is as shown in fig. 3a, the piezoceramic displacement actuator is connected with the base 300, and the end face of the swing arm 103 is at a distance of about 5um from the mover 200; neither the thickness displacement stack 101 nor the bend displacement stack 102 apply an electric field; secondly, applying an electric field E to the electrode 108a part of the bending displacement stack 102 to maximize the bending degree of the ceramic pieces, and applying the electric field E to the thickness displacement stack 101 to make the end point of the swing arm 103 contact the mover 200 and apply a certain pressure, as shown in FIG. 3 b; thirdly, applying an electric field E to the electrode 108b portion of the bending displacement stack 102 until the electric field is consistent with the electric field applied to the electrode 108a portion, driving the swing arm 103 to return to the middle position, and simultaneously pushing the mover 200 to move to the right, applying the electric field E to the thickness displacement stack 101, and maintaining the pressure applied by the swing arm 103 to the mover 200, as shown in fig. 3 c; fourthly, reducing the electric field applied to the electrode 108a, so that the bending displacement stack 102 bends and swings rightwards, pushing the mover 200 to move rightwards continuously, applying the electric field to the thickness displacement stack 101, and maintaining the pressure applied to the mover by the swing arm, as shown in fig. 3 d; in the fifth step, the electric field applied to the thickness displacement stack 101 is removed to release the swing arm 103 from contact with the mover 200, and then the electric field applied to the bending displacement stack 102 is removed to finally return the piezoceramic displacement driver to the initial state shown in fig. 3 a.

In the first embodiment, the maximum swing displacement that can be achieved is determined by the performance characteristics of the piezoelectric ceramic and the displacement magnification of the swing arm, in this embodiment, the displacement that can be achieved by the piezoelectric ceramic is 0.1% of the height of the ceramic chip, and the magnification of the swing arm is 1 times, which is determined by the maximum voltage applied to the electrode 106; the maximum displacement amount of the half swing in this example is 5um, and the maximum displacement amount of the full swing is 10 um.

In this embodiment, the maximum thrust of the thickness displacement stack is 4000 newtons, and the maximum thrust of the bending displacement stack is 1800 newtons, so the maximum driving force that the piezoelectric ceramic displacement driver can output is not more than 1800 newtons; the actual driving force depends on the product of the static friction coefficient of the contact surface of the rotor and the swing arm and the vertical thrust of the swing arm driven by the thickness displacement stack to the rotor, and the maximum thrust provided by the example is 800 newtons.

Fig. 5 is a schematic structural diagram of a piezoceramic displacement driver according to a second embodiment of the present invention, and as shown in fig. 3, the piezoceramic displacement driver according to this embodiment includes a bending displacement stack 102, a thickness displacement stack 101, and a swing arm 103, wherein one end of the bending displacement stack 102 is connected to a base 300, the other end of the bending displacement stack 103 is connected to the thickness displacement stack 101, and the thickness displacement stack 101 is further connected to the swing arm 103. The height of the bending displacement stack is 6mm, the height of the thickness displacement stack is 10mm, the height of the swing arm is 2mm, and the cross sections of the ceramic sheets which are stacked to form the bending displacement stack 102 and the thickness displacement stack 101 are squares with 10mm side lengths. Since the thickness displacement stack 101 also acts as a swing arm when the bending displacement stack 102 acts, the swing displacement amplification factor of the present invention is 1.3 times, so that the single-step maximum driving displacement of the piezoelectric ceramic displacement driver of this embodiment is 13 um.

The difference between this embodiment and the first embodiment is the positions of the bending displacement stack and the thickness displacement stack, the bending displacement stack in the first embodiment is located between the thickness displacement stack and the flapping arm, and the thickness displacement stack in the second embodiment is located between the bending displacement stack and the swinging arm, and the specific structures of the bending displacement stack 102 and the thickness displacement stack 101 are the same as those of the first embodiment, and are not repeated here.

Fig. 6 is a schematic structural diagram of a piezoceramic displacement driver according to a third embodiment of the invention, and fig. 7 is a schematic structural diagram of electrodes of electrode layers of the bending displacement stack of fig. 6. As shown in fig. 6-7, in this embodiment, the piezoceramic displacement driver still includes a thickness displacement stack 101, a bending displacement stack 102, and a swing arm 104. Wherein the thickness displacement stack 101 is used to connect the base and the swing arm 104 contacts the mover. In the embodiment, the main difference is in the structure of the electrode layers, as shown in fig. 7, the electrode layers include spaced apart

electrode layers

109a, 109b, 109c, and 109, and the

electrode layers

109a, 109b, 109c, and 109d are fan-shaped structures, each spaced apart from the other.

In operation, the bend displacement stack can be made to oscillate in the left direction by applying a positive displacement electric field to

electrode layers

109a and 109d, and no electric field or an electric field in the opposite direction to electrode

layers

109b and 109 c; or by applying a positive displacement electric field to the electrode layers 109b and 109c, while applying no electric field or an electric field in the opposite direction to the

electrode layers

109a and 109d, thereby forming a wobble in the right direction; or by applying a positive displacement electric field to the

electrode layers

109a and 109b, while applying no electric field or an electric field in the opposite direction to the electrode layers 109c and 109d, thereby causing the stack to swing in the backward (upward in fig. 7) direction; or by applying a positive displacement electric field to the electrode layers 109c and 109d, while applying no electric field or an electric field in the opposite direction to the

electrode layers

109a and 109b, thereby forming a swing in the forward direction. Therefore, the piezoelectric ceramic displacement driver of the embodiment can realize displacement control for controlling two degrees of freedom in the X direction and the Y direction through one bending displacement stack.

Fig. 8 is a schematic structural view of a piezoceramic displacement actuator according to a fourth embodiment of the present invention. As shown in fig. 8, the piezoceramic displacement driver comprises a thickness displacement stack 101, a bending displacement stack 102 and a swing arm 105. The structures of the thickness displacement stack 101 and the bend displacement stack 102 are the same as those of the first embodiment, and will not be described again. As shown in fig. 8, the swing arm 105 is cylindrical, and has a groove 105a on its upper end surface, a protruding ball 201 extends from the lower bottom surface of the mover 200, and the protruding ball 201 is engaged with the groove 105a, so that the axial driving force provided by the swing of the bending displacement stack 102 can be transmitted through the structure of the swing arm 105, and directly pushes the structure 201 of the mover 200, so as to operate the mover 200.

In this embodiment, the action of the swing arm 105 on the mover 200 is not by way of static friction force, but by the engagement of the groove 105a on the swing arm 105 and the protruding ball 201 on the mover 200, the movement of the mover is directly driven by the swing of the bending displacement stack, and therefore, the piezoceramic displacement driver is not limited to the way of driving by static friction force.

Fig. 9 is a schematic structural view of a piezoelectric ceramic displacement actuator according to a fifth embodiment of the present invention. As shown in fig. 9, the piezoceramic displacement driver includes a thickness displacement stack 101, a bending displacement stack 102, and a swing arm 106. The structures of the thickness displacement stack 101 and the bend displacement stack 102 are the same as those of the first embodiment, and will not be described again. The present embodiment differs from the above embodiments mainly in the structure of the swing arm 106. In the present embodiment, the swing arm 106 is cylindrical, and is provided with a protrusion 106a on an upper surface, and the protrusion 106a contacts with the mover and drives the mover to move. The swing arm 106 is driven to move in an axial displacement manner during the bending action of the bending displacement stack 102, so that the swing arm can output axial displacement and thrust. Those skilled in the art will appreciate that the swing arm 106 may be configured as a T-shaped structure as shown, however, the shape of the swing arm may be configured as another shape, and is not limited to a triangle, a hemisphere, a T-shape, etc.

The high precision nano-displacement linear stepper motor of the present invention is described with continued reference to fig. 1-11.

Fig. 10 is a schematic structural view of a first piezoceramic displacement actuator 30 according to the present invention, and fig. 11 is a schematic structural view of a second piezoceramic displacement actuator 40 according to the present invention. As shown in fig. 10-11, the first piezoceramic displacement driver 30 comprises a thickness displacement stack 101, a bending displacement stack 102 and a swing arm 103. The thickness displacement stack 101, the bending displacement stack 102 and the swing arm 103 form a piezoceramic actuator that can provide both radial and axial displacement. The second piezoceramic driver 40 comprises a thickness displacement stack 101 and a swing arm 103. The thickness displacement stack and the wobble form a piezoelectric ceramic actuator providing radial displacement.

Referring back to fig. 1, a pair of first piezoceramic drivers 30 are respectively mounted on the motor housing from both sides of the motor mover 20 and are axisymmetric with respect to the motor mover 20. A pair of second piezoceramic drivers 40 are respectively mounted on the motor housing from both sides of the motor mover 20 and are axisymmetric with respect to the motor mover 20.

The following describes the movement process of the high-precision nano-displacement linear stepping motor according to an embodiment of the present invention with reference to fig. 12a to 12 f.

In the present embodiment, the initial state is shown in fig. 12a, the end faces of the first piezoceramic displacement driver 30 and the second piezoceramic displacement driver 40 are in contact with the motor mover 20, and a certain pressure is provided by the motor housing.

In one operation, as shown in fig. 12b, an electric field is applied to the second piezoelectric ceramic displacement actuator 40, so that the second piezoelectric ceramic displacement actuator 40 extends by 10um, and the contact surface between the first piezoelectric ceramic actuator 30 and the motor mover 20 is released.

In the second operation, as shown in fig. 12c, an electric field is applied to the bending displacement stack of the first piezoceramic displacement actuator 30, so that the bending displacement stack of the first piezoceramic displacement actuator 30 bends in the left direction, and the swing arm of the first piezoceramic displacement actuator 30 swings left.

In the third operation, as shown in fig. 12d, the electric field applied to the second piezoceramic displacement actuator 40 is reduced to 0V, and the electric field is applied to the thickness displacement stack on the first piezoceramic displacement actuator 30, so that the swing arm of the first piezoceramic displacement actuator 30 contacts the motor mover 20, and the swing arm of the second piezoceramic displacement actuator 40 is separated from contact with the motor mover.

Action four as shown in fig. 12e, the electric field of the bending displacement stack applied to the first displacement driver 30 is adjusted, so that the bending displacement stack on the first displacement driver 30 swings to the right, the motor mover 20 moves to the right, and the axial displacement of 5um can be divided into 1nm displacement equal parts by subdividing the control electric field, thereby realizing the control of the nano displacement precision.

When the required displacement is reached, operation five is performed, as shown in fig. 12f, the adjustment of the electric field applied to the bending displacement stack of the first piezoelectric ceramic displacement actuator 30 is stopped, the electric field is applied to the second piezoelectric ceramic actuator 40, the position of the mover is fixed, and then the electric field applied to the first piezoelectric ceramic actuator 30 is lowered to 0v, and the state shown in fig. 10b is reached. If the operation is stopped, the electric field applied to the piezoelectric ceramic actuator is stopped, and the state shown in fig. 10a is restored. The motor can enable the rotor to reach a required position through the continuous action of the steps, and the motor rotor can be fixed through the pretightening force of the motor shell when the motor does not act.

Example 2

The present embodiment is different from embodiment 1 in that the second piezoelectric ceramic actuator is the same as the first piezoelectric ceramic actuator, and includes a thickness displacement stack, a bending displacement stack, and a swing arm. The high-precision nano-displacement linear stepping motor of example 2 will be described with reference to fig. 13a to 13 h.

In embodiment 2, the initial state is shown in fig. 13a, the end faces of the first piezoceramic displacement driver 30 and the second piezoceramic displacement driver 40 are in contact with the motor mover 20 and a certain pressure is provided by the motor housing.

In one operation, as shown in fig. 13b, an electric field is applied to the second piezoelectric ceramic displacement actuator 40, so that the second piezoelectric ceramic actuator 40 extends by 10um, and the contact surface between the first piezoelectric ceramic actuator 30 and the motor mover 20 is released.

In the second operation, as shown in fig. 13c, an electric field is applied to the bending displacement stack of the first piezoelectric ceramic actuator 30, so that the bending displacement stack of the first piezoelectric ceramic actuator 30 is bent in the left direction, and the swing arm of the first piezoelectric ceramic actuator 30 swings left.

In the third operation, as shown in fig. 13d, the electric field applied to the second piezoelectric ceramic driver is reduced to 0V, and the electric field is applied to the thickness displacement stack of the first piezoelectric ceramic driver 30, so that the swing arm of the first piezoelectric ceramic driver 30 contacts the motor mover 20, and the thickness displacement stack of the second piezoelectric ceramic driver is reduced to 0V, so that the swing arm of the second piezoelectric ceramic driver is separated from the contact with the motor mover.

In the fourth operation, as shown in fig. 13e, the electric field applied to the bending displacement stack of the first piezoelectric ceramic actuator 30 is adjusted to return the swing arm of the first piezoelectric ceramic actuator 30 to the middle position, and simultaneously, the electric field is applied to the bending displacement stack of the second piezoelectric ceramic actuator 40 to swing the swing arm of the second piezoelectric ceramic actuator 40 to the left.

Action five as shown in fig. 13f, the electric field applied to the bending displacement stack of the first piezoceramic driver 30 is adjusted so that the bending displacement stack of the first piezoceramic driver 30 continues to swing to the right, thereby moving the mover to the right.

Sixth, as shown in fig. 13g, the electric field applied to the bending displacement stack of the second piezoelectric ceramic actuator 40 is adjusted, so that the swing arm of the second piezoelectric ceramic actuator swings to the right, the electric field of the bending displacement stack of the first piezoelectric ceramic actuator is lowered to 0V, and the swing arm of the first piezoelectric ceramic actuator 30 swings back to the initial position.

Action seven is as shown in fig. 13h, the electric field applied to the bending displacement stack of the second piezoelectric ceramic actuator 40 is adjusted, so that the swing arm of the second piezoelectric ceramic actuator 40 swings to the right, and the bending displacement stack of the first piezoelectric ceramic actuator 40 swings to the left.

When the first piezoelectric ceramic driver 30 and the second piezoelectric ceramic driver 40 repeatedly and alternately act, the rotor 20 can be driven to continuously move rightwards, and 5um axial displacement can be divided into 1nm displacement equal parts through a subdivision control electric field, so that the control of nanometer displacement precision is realized.

In the motor driving process, one group of the first piezoelectric ceramic driver 30 and the second piezoelectric ceramic driver 40 always drives the rotor 20 to act, and the other group of the first piezoelectric ceramic driver and the second piezoelectric ceramic driver are separated from the rotor 20, when the required position is reached, the voltage of the piezoelectric ceramic drivers of the action groups can be stopped to change, the piezoelectric ceramic drivers of the action groups completely reduce the electric field to 0V, then the electric field is pressurized to the highest working voltage, meanwhile, the applied electric field of the thickness displacement stack of the piezoelectric ceramic drivers of the action groups is reduced to 0V, the switching of the pressed piezoelectric ceramic groups is realized, the applied electric field of the bending piezoelectric ceramic stack is reduced to 0V, and then the applied electric fields of all the piezoelectric ceramic groups are reduced to 0V, so that the position of the rotor is.

When the motion sequence of the bending stacks of the first piezoceramic driver 30 and the second piezoceramic driver 40 is opposite, the mover 20 can move in the opposite direction, that is, the mover can be moved to the left.

Examples 3 to 4

Embodiments 3 and 4 of the high-precision nano-displacement linear stepping motor of the present invention are briefly described below. The difference between embodiment 3 and embodiment 4 and embodiment 2 is only the number of piezo-ceramic displacement actuators.

The structure of the nano-displacement linear stepping motor in the embodiment 3 is schematically shown in fig. 14, and four piezoelectric ceramic drivers are added. Namely, the nano-displacement linear stepping motor includes two pairs of first piezoelectric ceramic drivers 30 and two pairs of second piezoelectric ceramic drivers 40, and the two pairs of first piezoelectric ceramic drivers 30 and the two pairs of second piezoelectric ceramic drivers 40 are arranged in a row. In operation, the two pairs of first piezoceramic drivers 30 act in unison, and the two pairs of second piezoceramic drivers 40 act in unison.

Fig. 15 shows a schematic structure of embodiment 4 of the present invention, and fig. 15b is a side view of fig. 15a, to which four piezoelectric ceramic actuators are added. Namely, the nano-displacement linear stepping motor comprises two pairs of first piezoelectric ceramic drivers and two pairs of second piezoelectric ceramic drivers, wherein the two pairs of first piezoelectric ceramic drivers are arranged in a row, and the two pairs of second piezoelectric ceramic drivers are arranged in the other row. During the operation, the two pairs of first piezoelectric ceramic drivers 30 act in unison, and the two pairs of second piezoelectric ceramic drivers 40 act in unison.

Example 5

The structure of embodiment 5 of the nano-displacement linear stepping motor of the invention is schematically shown in fig. 16, a mover 20 is mounted on a motor housing 10 through a precision guide 201 and

sliders

202 and 203, and on the other side, piezoelectric

ceramic drivers

30 and 40 are mounted on the motor housing 10, and swing arms of the piezoelectric

ceramic drivers

30 and 40 are in contact with the mover 20.

Example 6

Fig. 17 shows a schematic structure of an embodiment 6 of the nano-displacement linear stepping motor according to the present invention, in which a pair of piezoelectric ceramic actuators 30 and a pair of piezoelectric ceramic actuators 40 are mounted on a mover 20, and when the mover moves, a swing arm of the piezoelectric ceramic actuator contacts a motor housing 10, and the piezoelectric ceramic actuator moves together with the mover.

Various embodiments of the nano-displacement linear stepper motor and piezoelectric ceramic displacement driver of the present invention are described above. Although the nano-displacement linear stepping motor in the embodiments is described with respect to only one or two piezoelectric ceramic displacement drivers, it will be understood by those skilled in the art that various piezoelectric ceramic displacement drivers in various embodiments of the present invention may be applied to the nano-displacement linear stepping motor in various embodiments.

While the preferred embodiments of the present invention have been illustrated and described in detail, it should be understood that various changes and modifications of the invention can be effected therein by those skilled in the art after reading the above teachings of the invention. Such equivalents are intended to fall within the scope of the claims appended hereto.

Claims

1. A nanometer displacement linear stepping motor is characterized by comprising a motor shell, a motor rotor, at least one pair of first piezoelectric ceramic drivers and at least one pair of second piezoelectric ceramic drivers,

the motor rotor is arranged in the motor shell,

the at least one pair of second piezoceramic drivers are symmetrically arranged with respect to the motor mover and mounted on the motor housing, an

The top ends of the at least one pair of first piezoelectric ceramic drivers are contacted with the motor rotor so as to provide at least axial acting force and axial displacement for driving the motor rotor to move, and the top ends of the at least one pair of second piezoelectric ceramic drivers are contacted with the motor rotor so as to provide at least radial acting force and radial displacement.

2. The nano-displacement linear stepper motor of claim 1, wherein the first piezo-ceramic driver comprises a bending displacement stack and a swing arm, the bending displacement stack is directly fabricated by a multi-piezo-ceramic sheet stacking or multi-layer co-firing process, wherein surfaces of the piezo-ceramic sheets of the bending displacement stack are covered with spaced electrode layers to form a first set of electrode layers and a second set of electrode layers.

In one embodiment, the first group of electrode layers is powered to form an angular bend in the bending displacement stack, then the second group of electrode layers is powered to restore the bending displacement stack to a vertical state, and then the voltage of the first group of electrode layers or the second group of electrode layers is reduced to zero to form an angular bend in the bending displacement stack again, so that the mover swings back and forth or moves in the same direction, wherein the swing arm is used for amplifying the displacement of the bending displacement stack.

3. The nano-displacement linear stepper motor of claim 2, wherein the first piezo-ceramic displacement driver further comprises a thickness displacement stack directly fabricated by a multi-piezo-ceramic sheet stacking or multi-layer co-firing process, and the surface of the piezo-ceramic sheet of the thickness displacement stack is covered with a full electrode layer, so that the first piezo-ceramic driver can also provide radial acting force and radial displacement.

4. The nano-displacement linear stepper motor of claim 1, wherein the second piezo-ceramic displacement driver comprises a thickness displacement stack and a swing arm, the thickness displacement stack is directly fabricated by a multi-piezo-ceramic sheet stacking or multi-layer co-firing process, and the surface of the piezo-ceramic sheet of the thickness displacement stack is covered with a full electrode layer, so that the second piezo-ceramic driver can provide radial acting force and radial displacement.

5. The nano-displacement linear stepper motor of claim 4, wherein the second piezo ceramic displacement driver further comprises a bending displacement stack mounted between the thickness displacement stack and the swing arm, such that the second piezo ceramic displacement driver is also capable of providing axial force and axial displacement.

6. The nano-displacement linear stepper motor of claim 1, comprising two pairs of first piezo ceramic drivers and two pairs of second piezo ceramic drivers, the two pairs of first piezo ceramic drivers and the two pairs of second piezo ceramic drivers aligned in a column.

7. The nano-displacement linear stepper motor of claim 1, comprising two pairs of first piezo ceramic drivers and two pairs of second piezo ceramic drivers, the two pairs of first piezo ceramic drivers aligned in a column and the two pairs of second piezo ceramic drivers aligned in another column.

in one embodiment, the height of the curved stack may be between 0.1mm-100 mm;

in one embodiment, the height of the swing arm is between 0.1mm and 100 mm.

8. The utility model provides a nanometer displacement linear stepping motor, its characterized in that, nanometer displacement linear stepping motor includes motor housing, motor active cell, at least a pair of first piezoceramics driver, guide rail and slider, one side of motor active cell is passed through guide rail and slider are installed motor housing's top, at least a pair of first piezoceramics driver is installed side by side motor housing's bottom, just first piezoceramics driver's top with motor active cell contacts and provides axial force and axial displacement at least.

9. The nano-displacement linear stepper motor of claim 8, wherein the first piezo-ceramic driver comprises a bending displacement stack and a swing arm, the bending displacement stack is directly fabricated by a multi-piezo-ceramic sheet stacking or multi-layer co-firing process, wherein surfaces of the piezo-ceramic sheets of the bending displacement stack are covered with spaced electrode layers to form a first set of electrode layers and a second set of electrode layers.

10. A nanometer displacement linear stepping motor is characterized by comprising a motor shell, a motor rotor, at least one pair of first piezoelectric ceramic drivers and at least one pair of second piezoelectric ceramic drivers, the motor rotor is mounted in the motor housing, the at least one pair of first piezoelectric ceramic drivers are symmetrically arranged with respect to the motor rotor and mounted on the motor rotor, the at least one pair of second piezoceramic drivers are symmetrically arranged about the motor mover and mounted on the motor mover, the top ends of the at least one pair of first piezoceramic drivers are contacted with the motor shell so as to provide at least axial acting force and axial displacement to drive the motor rotor to move, and the top ends of the at least one pair of second piezoceramic drivers are in contact with the motor housing so as to provide at least radial force and radial displacement.