Bow type piezoelectric linear motor and working method thereof

Abstract

The invention provides a bow-type piezoelectric linear motor and a working method thereof, the motor is composed of two sets of piezoelectric ceramic components, a sliding base, a self-adaptive guide rail and a base, the piezoelectric ceramic components are installed on the sliding base, the sliding base is installed on the base, and the self-adaptive guide rail is fixed on the base through a bolt. Trapezoidal electric signals with the phase difference of 90 degrees are applied to the two sets of laminated piezoelectric ceramics of the motor respectively, and linear operation of the motor can be achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of non-resonant piezoelectric linear motors, and in particular relates to a bow-type piezoelectric linear motor and a working method thereof. Background Art

[0002] Piezoelectric linear motors use the inverse piezoelectric effect of piezoelectric elements to transmit the micron-level vibrations generated by piezoelectric elements to the stator drive foot, and then convert them into linear motion through friction coupling. Unlike electromagnetic linear motors, piezoelectric linear motors have the advantages of fast response, high operating accuracy, frequent start and stop, and anti-electromagnetic interference. They have been applied in many cutting-edge technology fields such as ultra-precision machining, optical precision engineering, aerospace, and biomedicine.

[0003] At present, non-resonant piezoelectric linear motors have problems such as low repetitive operation accuracy, small output force and uneven performance. The reason is that the existing stator structure design is complex and has high requirements for processing accuracy and assembly accuracy, but the existing methods cannot meet the requirements. The performance consistency of the manufactured motor stator is poor, resulting in low repetitive operation accuracy of the motor, such as application number CN202210830268.2, invention name Four-bar direct-push piezoelectric linear motor. In addition, the use of more flexible hinges leads to insufficient stator stiffness and small motor output force, such as application number CN202011612252.1, invention name A kind of alternating rowing piezoelectric linear motor. Summary of the invention

[0004] The purpose of the present invention is to solve the defects of the above-mentioned prior art and provide a bow-type piezoelectric linear motor and a working method thereof, which has the advantages of simple structure, high repeatability, high rigidity and large output force.

[0005] The present invention adopts the following technical solution: The bow-type piezoelectric linear motor is composed of two sets of piezoelectric ceramic components, a sliding base, an adaptive guide rail and a base. The piezoelectric ceramic components are installed on the sliding base, the sliding base is installed on the base, and the adaptive guide rail is fixed on the base by bolts.

[0006] Furthermore, the two sets of piezoelectric ceramic components have the same structure, wherein the piezoelectric ceramic components are composed of a bow-type mechanism, a laminated piezoelectric ceramic, a warning tension spring and a pin; the laminated piezoelectric ceramic is installed inside the bow-type mechanism, and the two ends of the warning tension spring are respectively hooked on two pins on the bow-type mechanism to achieve pre-tightening of the laminated piezoelectric ceramic and the bow-type mechanism.

[0007] Furthermore, the bow-type mechanism has a flexible hinge and a driving foot, wherein the flexible hinges I and II, the flexible hinges V and VI are respectively located on the arcs of the two bow-type mechanisms, the flexible hinges III and IV, the flexible hinges VII and VIII are respectively located on the strings of the two bow-type mechanisms, and the driving foot I and II, the driving foot III and IV are respectively located at the two junctions of the arc and the string in the two bow-type mechanisms. Among them, the flexible hinge on the arc is responsible for adjusting the contraction and release of the bow-type mechanism, ensuring that the bow-type mechanism has sufficient rigidity while changing the movement direction of the driving foot, the flexible hinge on the string is responsible for adjusting the shear force generated when the motor is running, and preventing the laminated piezoelectric ceramics from being damaged by the shear force, and the driving foot is in close contact with the adaptive guide rail to push the sliding base to run in a straight line.

[0008] Furthermore, the sliding base is composed of a base, a cross roller guide rail I and a cross roller guide rail II. The base is a symmetrical structure, a threaded hole is opened on the base, and the piezoelectric ceramic component is installed on the base by bolts. The cross roller guide rail I and the cross roller guide rail II are each composed of two guide rails, one of which is fixedly installed on the base and the other is installed on the base. The cross roller guide rail I and the cross roller guide rail II enable the sliding base to move only along the guide rail direction.

[0009] Furthermore, the adaptive guide rail is composed of two ceramic strips, a ceramic strip plate, an optical axis, a compression spring, a ceramic strip support and an optical axis support. The left side of the ceramic plate is bonded to one of the ceramic strips, and a hole is opened on the right side of the ceramic plate, and the opening is connected to the optical axis. A compression spring is sleeved on the optical axis. The compression spring provides pre-pressure for the adaptive guide rail, so that when the motor is in a stationary state, the four driving feet are always in close contact with the ceramic strips, and when the motor is in a running state, two of the paired driving feet are in close contact with the ceramic strips. Another ceramic strip is mounted on the ceramic strip support, and the ceramic strip support is fixed on the base. One end of the optical axis support has a hole, and the opening is connected to the other end of the optical axis, which supports the compression spring. The optical axis support is also fixed on the base.

[0010] On the other hand, a working method of a bow-type piezoelectric linear motor is provided, comprising: In step 1.0-T / 4 cycle, one of the stacked piezoelectric ceramics is at the rising edge of the trapezoidal wave, the bow mechanism I in the corresponding piezoelectric ceramic component I begins to expand, and the corresponding driving feet I and II push the sliding base to the left for one step △x, and the motor is in operation; at the same time, the other stacked piezoelectric ceramic II is at a low potential, and the corresponding piezoelectric ceramic component II is not actuated.

[0011] Step 2. In the T / 4-T / 2 period, one stacked piezoelectric ceramic I is always at the highest potential of the trapezoidal wave, and the bow mechanism I in the corresponding piezoelectric ceramic component I remains expanded to the maximum position; at the same time, the other stacked piezoelectric ceramic II is at the rising edge of the trapezoidal wave, and the bow mechanism II in the corresponding piezoelectric ceramic component II begins to expand, but the corresponding driving feet III and IV fail to contact the ceramic strip, and the motor is in a clamped state.

[0012] Step 3. T / 2-3T / 4 period, one stacked piezoelectric ceramic I is at the falling edge of the trapezoidal wave, and the bow mechanism I in the corresponding piezoelectric ceramic component I begins to shrink. At the same time, the other stacked piezoelectric ceramic II is always at the highest potential of the trapezoidal wave, and the bow mechanism II in the corresponding piezoelectric ceramic component II remains stretched to the maximum position. Although the bow mechanism I begins to shrink at this time, the corresponding driving feet III and IV are in close contact with the ceramic strip under the action of the adaptive guide rail, while the corresponding driving feet I and II fail to contact the ceramic strip, so the sliding base does not retreat.

[0013] Step 4.3T / 4-T cycle, one stacked piezoelectric ceramic I is always at a low potential, and the bow-type mechanism I in the corresponding piezoelectric ceramic component I remains contracted to the minimum position. At the same time, the other stacked piezoelectric ceramic II is at the falling edge of the trapezoidal wave, and the bow-type mechanism II in the piezoelectric ceramic component II begins to contract. Under the action of the adaptive guide rail, the corresponding driving feet III and IV are in close contact with the ceramic strip, and the sliding base moves one step △x to the left as the bow-type mechanism contracts, and the motor is in operation.

[0014] Furthermore, the method also includes changing the phase difference of the electrical signal to enable the bow-type piezoelectric linear motor to run to the right.

[0015] Beneficial effects of the present invention: (1) The present invention provides a bow-type piezoelectric linear motor and a working method thereof, which adopts a bow-type mechanism to replace the complex stator structure of the existing solution, reduces the requirements for processing accuracy and assembly accuracy, improves the consistency of the output performance of the piezoelectric ceramic assembly, and thus improves the repeatability of the motor. In addition, the bow-type mechanism reduces the use of flexible hinges, increases structural rigidity, and improves the motor output force. When the motor is running, the bow-type mechanism contracts and releases like a bow, and the driving feet at both ends are in close contact with the ceramic strip, pushing the sliding base to run linearly.

[0016] (2) The bow-type piezoelectric linear motor and its working method provided by the present invention use an adaptive guide rail to provide pre-pressure for the motor. As the sliding base runs, the compression spring of the adaptive guide rail can always ensure that the two driving feet are in close contact with the ceramic strip, avoiding slipping caused by poor contact of the motor driving feet due to processing errors and assembly errors, thereby improving the stability of the motor operation.

[0017] (3) The bow-type piezoelectric linear motor and its working method provided by the present invention use a piezoelectric ceramic component and a sliding base to form a "mover", breaking the existing solution of using a piezoelectric ceramic component as a "stator" and a slide as a "mover", further improving the compactness of the motor structure, reducing the motion transmission loss between the various components of the motor, and thus improving the repeatability of the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A perspective view of the present invention; Figure 2 It is a front view of the present invention; Figure 3 It is the structural diagram of the piezoelectric ceramic component; Figure 4 It is the structural diagram of the bow mechanism; Figure 5 This is a structural diagram of the sliding base; Figure 6 is a schematic diagram of the adaptive guide rail structure; Figure 7 Schematic diagram of the contact between the adaptive guide rail and the driving foot; Figure 8 : is a diagram of the excitation signal of the stacked piezoelectric ceramic, wherein (a) is the excitation signal applied to the stacked piezoelectric ceramic I, and (b) is the excitation signal applied to the stacked piezoelectric ceramic II; Fig. 9 This is the working principle diagram of the piezoelectric motor.

[0019] In the figure: 1a-piezoelectric ceramic component I, 1b-piezoelectric ceramic component II, 2-sliding base, 3-adaptive guide rail, 4-base; a1-bow mechanism Ⅰ, b1-bow mechanism Ⅱ, a2-laminated piezoelectric ceramics Ⅰ, b2-laminated piezoelectric ceramics Ⅱ, a3-preload spring Ⅰ, b3-warning spring Ⅱ, a4-pin Ⅰ, b4-pin Ⅱ; c1-flexible hinge I, c2-flexible hinge II, c3-flexible hinge III, c4-flexible hinge IV, c5-flexible hinge V, c6-flexible hinge VI, c7-flexible hinge VII, c8-flexible hinge VIII; d1-driving foot I, d2-driving foot II, d3-driving foot III, d4-driving foot IV; 21-base, 22-cross roller guide rail I, 23-cross roller guide rail II, 31-ceramic strip, 32-ceramic strip plate, 33-optical axis, 34-compression spring, 35-ceramic strip support, 36-optical axis support. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention is described clearly and completely below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] like Figure 1-Figure 2 As shown, the bow-type piezoelectric linear motor of the present invention is composed of a piezoelectric ceramic component, a sliding base 2, an adaptive guide rail 3 and a base 4. The piezoelectric ceramic component Ⅰ1a and the piezoelectric ceramic component Ⅱ1b are both mounted on the sliding base 2 by bolts, the sliding base 2 is mounted on the base 4 by bolts, the adaptive guide rail 3 is fixed on the base 4 by bolts, and the adaptive guide rail 3 is used to provide pre-pressure.

[0022] like Figure 3 As shown, the piezoelectric ceramic component Ⅰ1a is composed of a bow mechanism Ⅰa1, a laminated piezoelectric ceramic Ⅰa2, a warning tension spring Ⅰa3 and a pin Ⅰa4; the laminated piezoelectric ceramic Ⅰa2 is installed inside the bow mechanism Ⅰa1, and the two ends of the warning tension spring Ⅰa3 are respectively hooked on the two pins Ⅰa4 of the bow mechanism Ⅰa1, and the laminated piezoelectric ceramic Ⅰa2 and the bow mechanism Ⅰa1 are pre-tightened by the tension generated by the contraction of the warning tension spring Ⅰa3 itself. The piezoelectric ceramic component Ⅱ1b is composed of a bow mechanism Ⅱb1, a laminated piezoelectric ceramic Ⅱb2, a warning tension spring Ⅱb3 and a pin Ⅱb4. The structure of the piezoelectric ceramic component Ⅱ1b is the same as that of the piezoelectric ceramic component Ⅰ1a, and will not be repeated.

[0023] like Figure 4As shown, the bow-type mechanism Ⅰa1 has a flexible hinge and a driving foot, the flexible hinge Ⅰc1 and the flexible hinge Ⅱc2 are respectively located on the arc of the bow-type mechanism Ⅰa1, the flexible hinge Ⅲc3 and the flexible hinge Ⅳc4 are respectively located on the chord of the bow-type mechanism Ⅰa1, and the driving foot Ⅰd1 and the driving foot Ⅱd2 are respectively located at the two junctions of the arc and the chord. Among them, the flexible hinge Ⅰc1 and the flexible hinge Ⅱc2 are responsible for adjusting the bow-type mechanism Ⅰa1 to contract and release like a bow, ensuring that the bow-type mechanism Ⅰa1 has sufficient rigidity while transforming the movement direction of the driving foot Ⅰd1 and the driving foot Ⅱd2, that is, the vertical deformation of the laminated piezoelectric ceramic Ⅰa2 is transformed into the vertical and horizontal movement of the driving foot Ⅰd1 and the driving foot Ⅱd2; the flexible hinge Ⅲc3 and the flexible hinge Ⅳc4 are responsible for adjusting the shear force generated when the motor is running, so as to prevent the laminated piezoelectric ceramic Ⅰa2 from being damaged by the shear force, and the driving foot Ⅰd1 and the driving foot Ⅱd2 are in close contact with the adaptive guide rail 3 to push the sliding base 2 to run in a straight line. The bow-type mechanism IIb1 includes a flexible hinge Vc5, a flexible hinge VIc6, a flexible hinge VIIc7, a flexible hinge VIIIc8, a driving foot IIId3, and a driving foot IVd4. The structure of the bow-type mechanism IIb1 is the same as that of the bow-type mechanism Ia1, and will not be repeated herein.

[0024] like Figure 5 As shown, the sliding base 2 is composed of a base 21, a cross roller guide rail I 22 and a cross roller guide rail II 23. The base 21 is a symmetrical structure, and a threaded hole is opened on the base 21. The piezoelectric ceramic component I 1a and the piezoelectric ceramic component II 1b are both installed on the base 21 by bolts. Figure 2 As shown, the cross roller guide I 22 and the cross roller guide II 23 are both composed of two guide rails, one of which is fixedly mounted on the base 21, and the other is mounted on the base 4. The cross roller guide I 22 and the cross roller guide II 23 enable the sliding base 2 to move only along the guide rail direction.

[0025] like Figure 6 and Figure 7As shown, the adaptive guide rail 3 is composed of two ceramic strips 31, a ceramic strip plate 32, an optical axis 33, a compression spring 34, a ceramic strip support 35 and an optical axis support 36. The ceramic strip 31 is in contact with the driving foot Id1, the driving foot IId2, the driving foot IIId3 and the driving foot IVd4. The left side of the ceramic plate 32 is bonded to one of the ceramic strips 31, and the right side of the ceramic plate 32 is opened, and the opening is connected to the optical axis 33. A compression spring 34 is sleeved on the optical axis 33, and the optical axis 33 plays a guiding role and limits the swing of the compression spring 34. The compression spring 34 provides pre-pressure for the adaptive guide rail 3, so that the driving foot Id1, the driving foot IId2, the driving foot IIId3 and the driving foot IVd4 are always in close contact with the ceramic strip 31 when the motor is in a stationary state. One end of the optical axis support 36 is opened, and the opening is connected to the other end of the optical axis 33, which plays a supporting role for the compression spring 34. The optical axis support 36 is also fixed to the base 4 by bolts. Another ceramic bar 31 is mounted on the ceramic bar support 35, and the ceramic bar support 35 is fixed to the base 4 by bolts.

[0026] like Figure 8 , Fig. 9 As shown, the present invention also provides a working method of a bow-type piezoelectric linear motor. When an electrical signal is applied to the laminated piezoelectric ceramics Ia2 and the laminated piezoelectric ceramics IIb2, the linear motor will run a distance of 2△x to the left. The specific analysis process is as follows: In the 0-T / 4 period, the laminated piezoelectric ceramic Ⅰa2 is at the rising edge of the trapezoidal wave, the bow mechanism Ⅰa1 in the piezoelectric ceramic component Ⅰ1a begins to expand, and the driving foot Ⅰd1 and the driving foot Ⅱd2 push the sliding base 2 to the left for one step △x, and the motor is in operation; at the same time, the laminated piezoelectric ceramic Ⅱb2 is at a low potential, and the piezoelectric ceramic component Ⅱ1b is not actuated.

[0027] During the T / 4-T / 2 period, the stacked piezoelectric ceramic Ia2 is always at the highest potential of the trapezoidal wave, and the bow-type mechanism Ia1 in the piezoelectric ceramic component I1a remains expanded to the maximum position; at the same time, the stacked piezoelectric ceramic IIb2 is at the rising edge of the trapezoidal wave, and the bow-type mechanism IIb1 in the piezoelectric ceramic component II1b begins to expand, but the driving feet IIId3 and IVd4 fail to contact the ceramic strip 31, and the motor is in a clamped state.

[0028] In the T / 2-3T / 4 period, the stacked piezoelectric ceramic Ia2 is at the falling edge of the trapezoidal wave, and the bow-type mechanism Ia1 in the piezoelectric ceramic component I1a begins to shrink. At the same time, the stacked piezoelectric ceramic IIb2 is always at the highest potential of the trapezoidal wave, and the bow-type mechanism IIb1 in the piezoelectric ceramic component II1b remains stretched to the maximum position. Although the bow-type mechanism Ia1 begins to shrink at this time, the driving feet IIId3 and IVd4 are in close contact with the ceramic strip 31 under the action of the adaptive guide rail 3, while the driving feet Id1 and IId2 fail to contact the ceramic strip 31, so the sliding base 2 does not retreat.

[0029] In the 3T / 4-T period, the stacked piezoelectric ceramic Ia2 is always at a low potential, and the bow-type mechanism Ia1 in the piezoelectric ceramic component I1a remains contracted to the minimum position. At the same time, the stacked piezoelectric ceramic IIb2 is at the falling edge of the trapezoidal wave, and the bow-type mechanism IIb1 in the piezoelectric ceramic component II1b begins to contract. Under the action of the adaptive guide rail 3, the driving foot IIId3 and the driving foot IVd4 are in close contact with the ceramic strip 31. The sliding base 2 moves one step △x to the left as the bow-type mechanism b1 contracts, and the motor is in operation.

[0030] By the same logic, by exchanging the electrical signals applied to the stacked piezoelectric ceramic Ⅰa2 and the stacked piezoelectric ceramic Ⅱb2, that is, changing the phase difference of the electrical signals, the motor can be made to run to the right.

[0031] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. Bow-type piezoelectric linear motor, characterized in that: It consists of two sets of piezoelectric ceramic components, a sliding base, an adaptive guide rail and a base. The piezoelectric ceramic components are installed on the sliding base, the sliding base is installed on the base, and the adaptive guide rail is fixed on the base by bolts.

2. The motor according to claim 1, characterized in that The two sets of piezoelectric ceramic components have the same structure, wherein the piezoelectric ceramic components are composed of a bow-type mechanism, a laminated piezoelectric ceramic, a warning tension spring and a pin; the laminated piezoelectric ceramic is installed inside the bow-type mechanism, and the two ends of the warning tension spring are respectively hooked on the two pins on the bow-type mechanism to achieve pre-tightening of the laminated piezoelectric ceramic and the bow-type mechanism.

3. The motor according to claim 2, characterized in that The bow-type mechanism has a flexible hinge and a driving foot. Flexible hinges I and II, flexible hinges V and VI are respectively located on the arcs of the two bow-type mechanisms. Flexible hinges III and IV, flexible hinges VII and VIII are respectively located on the strings of the two bow-type mechanisms. Driving feet I and II, driving feet III and IV are respectively located at the two junctions of the arcs and strings of the two bow-type mechanisms. Among them, the flexible hinges on the arcs are responsible for adjusting the contraction and release of the bow-type mechanism to ensure that the bow-type mechanism has sufficient rigidity while changing the movement direction of the driving foot. The flexible hinges on the strings are responsible for adjusting the shear force generated when the motor is running to prevent the laminated piezoelectric ceramics from being damaged by the shear force. The driving foot is in close contact with the adaptive guide rail to push the sliding base to run in a straight line.

4. The motor according to claim 3, characterized in that The sliding base is composed of a base, a cross roller guide I and a cross roller guide II. The base is a symmetrical structure with a threaded hole. The piezoelectric ceramic component is installed on the base by bolts. The cross roller guide I and the cross roller guide II are each composed of two guide bars, one of which is fixedly installed on the base and the other is installed on the base. The cross roller guide I and the cross roller guide II enable the sliding base to move only along the guide direction.

5. The motor according to claim 4, characterized in that The adaptive guide rail is composed of two ceramic strips, a ceramic strip plate, an optical axis, a compression spring, a ceramic strip support and an optical axis support. The left side of the ceramic plate is bonded to one of the ceramic strips, and the right side of the ceramic plate has a hole, which is connected to the optical axis. A compression spring is sleeved on the optical axis to provide pre-pressure for the adaptive guide rail, so that when the motor is in a stationary state, the four driving feet are always in close contact with the ceramic strips. When the motor is in a running state, two of the paired driving feet are in close contact with the ceramic strips, and the other ceramic strip is installed on the ceramic strip support, and the ceramic strip support is fixed on the base. One end of the optical axis support has a hole, and the hole is connected to the other end of the optical axis, which supports the compression spring. The optical axis support is also fixed on the base.

6. A method for operating a bow-type piezoelectric linear motor, characterized in that: include: Step 1.0-T / 4 cycle, one of the stacked piezoelectric ceramics I is at the rising edge of the trapezoidal wave, the corresponding bow mechanism I in the piezoelectric ceramic component I begins to open, the corresponding driving foot I and driving foot II push the sliding base to the left for one step △x, and the motor is in operation; At the same time, the other stacked piezoelectric ceramic II is at a low potential, and the corresponding piezoelectric ceramic component II is not actuated; Step 2. During the T / 4-T / 2 period, one stacked piezoelectric ceramic I is always at the highest potential of the trapezoidal wave, and the bow mechanism I in the corresponding piezoelectric ceramic component I remains stretched to the maximum position; at the same time, another stacked piezoelectric ceramic II is at the rising edge of the trapezoidal wave, and the bow mechanism II in the corresponding piezoelectric ceramic component II begins to stretch, but the corresponding driving feet III and IV fail to contact the ceramic strip, and the motor is in a clamped state at this time; Step 3. In the T / 2-3T / 4 cycle, one stacked piezoelectric ceramic I is at the falling edge of the trapezoidal wave, and the bow mechanism I in the corresponding piezoelectric ceramic component I begins to contract. At the same time, the other stacked piezoelectric ceramic II is always at the highest potential of the trapezoidal wave, and the bow mechanism II in the corresponding piezoelectric ceramic component II remains stretched to the maximum position. Although the bow mechanism I begins to contract at this time, the corresponding driving feet III and IV are in close contact with the ceramic strip under the action of the adaptive guide rail, while the corresponding driving feet I and II fail to contact the ceramic strip, so the sliding base does not retreat. Step 4.3T / 4-T cycle, one stacked piezoelectric ceramic I is always at a low potential, and the bow-type mechanism I in the corresponding piezoelectric ceramic component I remains contracted to the minimum position. At the same time, the other stacked piezoelectric ceramic II is at the falling edge of the trapezoidal wave, and the bow-type mechanism II in the piezoelectric ceramic component II begins to contract. Under the action of the adaptive guide rail, the corresponding driving feet III and IV are in close contact with the ceramic strip, and the sliding base moves one step △x to the left as the bow-type mechanism II contracts, and the motor is in operation.

7. The working method of the bow-type piezoelectric linear motor according to claim 6, characterized in that: The method also includes changing the phase difference of the electrical signal to enable the bow-type piezoelectric linear motor to run to the right.

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