A bidirectional drive linear piezoelectric motor

Abstract

This invention belongs to the field of precision drive and positioning technology, specifically relating to a bidirectional drive linear piezoelectric motor. It includes a motor base, a preload mechanism, a linear guide rail, a linear slider, and a pair of piezoelectric mechanisms. Each piezoelectric mechanism includes a motor stator, a piezoelectric plate, and motor drive feet. The piezoelectric plate is fixed to the inner side of the side frame of the motor stator, and one end of the motor drive foot is fixed to the outer side of the corresponding side frame of the motor stator. This results in a pair of motor drive feet on the piezoelectric mechanisms being horizontally arranged and symmetrical about the y-axis of the motor base. The pair of motor drive feet and the linear slider are in inclined contact. When a sinusoidal excitation voltage of 90–360V is applied to the piezoelectric plate, it causes the corresponding side of the motor stator to vibrate periodically. Therefore, the linear piezoelectric motor of this invention uses single harmonic drive and can operate in a resonant state. It not only achieves bidirectional linear movement, but also the driving action of the linear piezoelectric motor is "push-disengage," thus eliminating sliding friction and improving the working efficiency of the piezoelectric motor.

Description

Technical Field

[0001] This invention belongs to the field of precision drive and positioning technology, specifically relating to a bidirectional drive linear piezoelectric motor. Background Technology

[0002] With the development of micro motors, the structure of piezoelectric motors has become increasingly diverse. There are inertial impact piezoelectric motors that cause unidirectional motion through asymmetrical excitation voltage, and inchworm motors that control the movement of the motor like a switch. In short, most piezoelectric motors at present are made by structural asymmetry and asymmetrical excitation voltage. However, current inertial impact motors have disadvantages such as low efficiency and small output force. Summary of the Invention

[0003] To overcome the shortcomings of the prior art, this invention provides a bidirectional drive linear piezoelectric motor that has higher tensile strength and higher output driving force compared to the piezoelectric stack used in traditional inertial impact piezoelectric motors, and is also dozens of times cheaper than the piezoelectric stack.

[0004] The technical solution of the present invention is as follows: a bidirectional drive linear piezoelectric motor, comprising a motor base 1, a pre-tightening mechanism, a linear slide rail 7, a linear slider 6, and a pair of piezoelectric mechanisms;

[0005] The linear slide rail 7 is fixedly installed on the motor base 1 along the x-axis direction, and the linear slider 6 is fitted on the linear slide rail 7.

[0006] Each piezoelectric mechanism includes a motor stator 5, a piezoelectric sheet 2, and a motor drive foot 51. The piezoelectric sheet 2 is fixed to one side of the motor stator 5, and one end of the motor drive foot 51 is fixed to the other side of the motor stator 5, so that a pair of motor drive feet on a pair of piezoelectric mechanisms are arranged horizontally and symmetrical about the y-axis of the motor base 1.

[0007] The pair of motor stators on the pair of piezoelectric mechanisms are fixedly installed at one end of the motor base 1 in the y-axis direction, so that the pair of motor drive feet and the linear slider 6 are in inclined contact.

[0008] The pre-tightening mechanism includes an upright first pre-tightening plate 4, an upright second pre-tightening plate 9, and a pre-tightening screw 8. The lower ends of the first pre-tightening plate 4 and the second pre-tightening plate 9 are fixed to both ends of the motor base 1 in the y-axis direction. The upper parts of the first pre-tightening plate 4 and the second pre-tightening plate 9 are provided with threaded holes. The pre-tightening screw 8 passes through the threaded holes and is fixed by a nut.

[0009] When the piezoelectric element 2 is supplied with a sinusoidal excitation voltage of 90-360V, it causes the corresponding side of the motor stator 5 to vibrate, causing the motor drive foot 51 to abut against the linear slider 6, driving the linear slider 6 to slide along the linear slide rail 7. A pair of motor drive feet can drive the linear slider 6 to move bidirectionally along the y-axis of the motor base 1.

[0010] Furthermore, the lower end of the linear slide rail 7 is provided with a slide rail base plate 71, and a pair of waist-shaped holes 72 are provided on the slide rail base plate 71. The linear slide rail 7 is fixedly installed along the x-axis direction of the motor base 1 through the cooperation of the waist-shaped holes and bolts. A horizontally arranged dovetail groove is provided on one side of the linear slide rail 7, and the corresponding side of the linear slider 6 is a dovetail slide platform. The dovetail slide platform is fitted in the dovetail groove, so that the linear slider 6 slides along the direction of the linear slide rail 7.

[0011] Furthermore, each of the motor stators 5 is a horizontally arranged rectangular frame. The piezoelectric sheet 2 is fixedly connected to the inner side of the side frame corresponding to the linear slider 6, and one end of the motor drive foot 51 is fixedly connected to the outer side of the side frame, so that the motor drive foot 51 is arranged horizontally and makes contact with the linear slider 6 at an angle of 45°~75°.

[0012] Furthermore, the motor stator 5 is fixedly installed at one end of the motor base 1 in the y-axis direction by an inverted L-shaped support plate 3. The vertical plate of the L-shaped support plate 3 is fixedly connected to one end of the motor base 1 in the y-axis direction. A pair of motor stators are fixedly installed on the upper end of the horizontal plate of the L-shaped support plate 3, so that the front side frame of the rectangular frame and the linear slider 6 are arranged parallel and correspondingly. The piezoelectric sheet 2 is fixedly connected to the inner side of the front side frame, and one end of the motor drive foot 51 is fixedly connected to the outer side of the front side frame.

[0013] Furthermore, a first pre-tightening plate 4 is provided on the L-shaped support plate 3 corresponding to the rear side of the motor stator 5, so that the first pre-tightening plate 4 abuts against the rear side frame of the pair of motor stators 5.

[0014] The second preload plate 9 is installed upright on the motor base 1, so that the second preload plate 9 abuts against the side of the linear slide rail 7 away from the pair of motor stators. The preload screw 8 passes through the threaded hole and is fixed by the nut, so that the preload screw 8 is parallel to the y-axis direction of the motor base 1.

[0015] Adjusting the preload screw 8 allows the first preload plate 4 and the second preload plate 9 to apply clamping force, achieving vertical preload fixation when a pair of motor drive feet and linear slider 6 are in inclined contact.

[0016] Furthermore, the material of the pair of piezoelectric sheets is piezoelectric ceramic PZT-4, and the material of the pair of motor stators is carbon structural steel.

[0017] The beneficial effects of this invention are:

[0018] (1) A bidirectional drive linear piezoelectric motor of the present invention includes a motor base, a pre-tightening mechanism, a linear slide rail, a linear slider and a pair of piezoelectric mechanisms. The piezoelectric mechanism includes a motor stator, a piezoelectric sheet and a motor drive foot. The piezoelectric sheet is fixed on the inner side of the side frame of the motor stator, and one end of the motor drive foot is fixed on the outer side of the corresponding side frame of the motor stator, so that the pair of motor drive feet on the pair of piezoelectric mechanisms are arranged horizontally and symmetrical about the y-axis direction of the motor base. The pair of motor drive feet and the linear slider are in inclined contact.

[0019] When a sinusoidal excitation voltage of 90–360V is applied to the piezoelectric element, it drives the corresponding side of the motor stator to generate periodic vibration.

[0020] When the motor stator vibrates in the forward direction, the motor drive foot abuts against the linear slider, and the motor drive foot exerts a force on the linear slide rail in the direction of the motor drive foot. Since the vertical direction is pre-tightened and fixed by the pre-tightening mechanism, this driving force exerts a horizontal component force on the linear slide rail, which will push the linear slide rail to move in one direction. When the motor stator vibrates in the reverse direction, the motor drive foot will disengage from the linear slide rail. In this way, the linear slide rail can move linearly in one direction throughout the entire cycle. If the linear slide rail is to move linearly in the opposite direction, it is only necessary to supply another piezoelectric element with a sinusoidal signal, and it can move linearly in the opposite direction, thus realizing the bidirectional movement of the linear motor.

[0021] Therefore, the linear piezoelectric motor of the present invention adopts single harmonic drive and can work in the resonant state. It can not only realize bidirectional linear movement, but also the driving action of the linear piezoelectric motor is "push-disengage", so there is no sliding friction, which improves the working efficiency of the piezoelectric motor.

[0022] (2) The present invention provides a bidirectional drive linear piezoelectric motor that uses a 90-360V sinusoidal excitation voltage to drive the piezoelectric sheet. Compared with the piezoelectric stack used in traditional inertial impact piezoelectric motors, it has higher tensile strength, higher output driving force, and is dozens of times cheaper than the piezoelectric stack. Moreover, under the condition that the linear slider and linear guide rail are long enough, the stroke can theoretically be extended indefinitely, and it can be used as a silent linear guide rail electric slide to achieve infinite precision positioning. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of a bidirectional drive linear piezoelectric motor according to the present invention.

[0024] Figure 2 This is a schematic diagram of the installation structure of the motor base and a pair of piezoelectric mechanisms of the present invention.

[0025] Figure 3 This is an assembly diagram of the linear slider and linear guide rail of the present invention.

[0026] Figure 4 This is a schematic diagram of the pre-tightening mechanism of the present invention.

[0027] Figure 5 This is a diagram illustrating the use of the pre-tightening mechanism of the present invention.

[0028] Figure 6 This is a diagram showing the excitation voltage applied to the piezoelectric element when the linear piezoelectric motor of the present invention is working.

[0029] Figure 7 This is a schematic diagram illustrating the operating principle of the linear piezoelectric motor in its initial state according to the present invention.

[0030] Figure 8 This is a schematic diagram of the operating principle of the linear piezoelectric motor at time t1 of the present invention.

[0031] Figure 9 This is a schematic diagram of the operating principle of the linear piezoelectric motor at time t2 of the present invention.

[0032] Figure 10 This is a schematic diagram of the operating principle of the linear piezoelectric motor at time t3 of the present invention.

[0033] Figure 11 This is a schematic diagram illustrating the operating principle of the linear piezoelectric motor at time t4 of the present invention.

[0034] In the diagram above, the following components are listed: 1. Motor base; 2. Piezoelectric sheet; 3. L-shaped support plate; 4. First pre-tightening plate; 9. Second pre-tightening plate; 5. Motor stator; 51. Motor drive foot; 6. Linear slider; 7. Linear slide rail; 71. Slide rail base plate; 72. A pair of oblong holes; 8. Pre-tightening screw. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. Example

[0036] See Figure 1 and Figure 2 A bidirectional drive linear piezoelectric motor includes a motor base 1, a preload mechanism, a linear slide rail 7, a linear slider 6, and a pair of piezoelectric mechanisms.

[0037] The linear slide rail 7 is fixedly installed on the motor base 1 along the x-axis direction, and the linear slider 6 is fitted on the linear slide rail 7.

[0038] Each piezoelectric mechanism includes a motor stator 5, a piezoelectric sheet 2, and a motor drive foot 51. The piezoelectric sheet 2 is fixed to one side of the motor stator 5, and one end of the motor drive foot 51 is fixed to the other side of the motor stator 5, so that a pair of motor drive feet on a pair of piezoelectric mechanisms are arranged horizontally and symmetrical about the y-axis of the motor base 1.

[0039] The pair of motor stators on the pair of piezoelectric mechanisms are fixedly installed at one end of the motor base 1 in the y-axis direction, so that the pair of motor drive feet and the linear slider 6 are in inclined contact.

[0040] The pre-tightening mechanism includes an upright first pre-tightening plate 4, an upright second pre-tightening plate 9, and a pre-tightening screw 8. The lower ends of the first pre-tightening plate 4 and the second pre-tightening plate 9 are fixed to both ends of the motor base 1 in the y-axis direction. The upper parts of the first pre-tightening plate 4 and the second pre-tightening plate 9 are provided with threaded holes. The pre-tightening screw 8 passes through the threaded holes and is fixed by a nut.

[0041] When the piezoelectric element 2 is supplied with a sinusoidal excitation voltage of 90-360V, it causes the corresponding side of the motor stator 5 to vibrate, causing the motor drive foot 51 to abut against the linear slider 6, driving the linear slider 6 to slide along the linear slide rail 7. A pair of motor drive feet can drive the linear slider 6 to move bidirectionally along the y-axis of the motor base 1.

[0042] See Figure 3 The lower end of the linear slide rail 7 is provided with a slide rail base plate 71, and a pair of waist-shaped holes 72 are provided on the slide rail base plate 71. The linear slide rail 7 is fixedly installed along the x-axis direction of the motor base 1 through the cooperation of the waist-shaped holes and bolts. A horizontally arranged dovetail groove is provided on one side of the linear slide rail 7, and the corresponding side of the linear slider 6 is a dovetail slide platform. The dovetail slide platform is fitted in the dovetail groove, so that the linear slider 6 slides along the direction of the linear slide rail 7.

[0043] Each motor stator 5 is a horizontally arranged rectangular frame. The piezoelectric sheet 2 is fixedly connected to the inner side of the side frame corresponding to the linear slider 6. One end of the motor drive foot 51 is fixedly connected to the outer side of the side frame, so that the motor drive foot 51 is arranged horizontally and makes contact with the linear slider 6 at an angle of 45° to 75°.

[0044] Furthermore, the motor stator 5 is fixedly installed at one end of the motor base 1 in the y-axis direction by an inverted L-shaped support plate 3. The vertical plate of the L-shaped support plate 3 is fixedly connected to one end of the motor base 1 in the y-axis direction. A pair of motor stators are fixedly installed on the upper end of the horizontal plate of the L-shaped support plate 3, so that the front side frame of the rectangular frame and the linear slider 6 are arranged parallel and correspondingly. The piezoelectric sheet 2 is fixedly connected to the inner side of the front side frame, and one end of the motor drive foot 51 is fixedly connected to the outer side of the front side frame.

[0045] See Figure 4 and Figure 5 The L-shaped support plate 3 corresponding to the rear side of the motor stator 5 is provided with a first pre-tightening plate 4, so that the first pre-tightening plate 4 abuts against the rear side frame of the pair of motor stators 5; the second pre-tightening plate 9 is installed upright on the motor base 1, so that the second pre-tightening plate 9 abuts against the side of the linear slide rail 7 away from the pair of motor stators; the pre-tightening screw 8 passes through the threaded hole and is fixed by the nut, so that the pre-tightening screw 8 is parallel to the y-axis direction of the motor base 1;

[0046] Adjusting the preload screw 8 allows the first preload plate 4 and the second preload plate 9 to apply clamping force, achieving vertical preload fixation when a pair of motor drive feet and linear slider 6 are in inclined contact.

[0047] The pair of piezoelectric elements are made of piezoelectric ceramic PZT-4, and the pair of motor stators are made of carbon structural steel.

[0048] See Figures 6-11 From time 0 to t1, the piezoelectric element 2 vibrates in the forward direction and drives the linear slider 6 to move to the right. From time t1 to t2, the piezoelectric element 2 moves to its maximum distance in the forward direction. At this time, the motor drive foot 51 has driven the linear slider 6 to move a distance ΔX. Then the excitation voltage gradually decreases until it returns to its original state. During this time period, the motor drive foot 51 does not provide any forward thrust to the linear slider 6, and the linear slider 6 remains stationary. From time t2 to t3, the piezoelectric element 2 begins to vibrate in the reverse direction. At this time, the motor drive foot 51 disengages from the linear slider 6, so the linear slider 6 remains stationary. From time t3 to t4, the excitation voltage gradually decreases, and the piezoelectric element 2 gradually returns to its initial state. During this time period, the motor drive foot 51 remains disengaged from the linear slider 6, and the linear slide rail 7 remains stationary.

[0049] By repeating the above actions, the linear motor can achieve unidirectional linear motion on a macroscopic scale. By applying a sinusoidal excitation voltage to the piezoelectric element 2 on the stator of another motor, linear motion in the opposite direction can be achieved.

[0050] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A bidirectional drive linear piezoelectric motor, characterized in that: It includes a motor base (1), a preload mechanism, a linear slide rail (7), a linear slider (6), and a pair of piezoelectric mechanisms; The linear slide rail (7) is fixedly installed on the motor base (1) along the x-axis direction, and the linear slider (6) is fitted on the linear slide rail (7). Each piezoelectric mechanism includes a motor stator (5), a piezoelectric sheet (2), and a motor drive foot (51). The piezoelectric sheet (2) is fixed on one side of the motor stator (5), and one end of the motor drive foot (51) is fixed on the other side of the motor stator (5), so that a pair of motor drive feet on a pair of piezoelectric mechanisms are arranged horizontally and symmetrical about the y-axis direction of the motor base (1). The pair of motor stators on the pair of piezoelectric mechanisms are fixedly installed at one end of the motor base (1) in the y-axis direction, so that the pair of motor drive feet and the linear slider (6) are in inclined contact; The pre-tightening mechanism includes an upright first pre-tightening plate (4), an upright second pre-tightening plate (9), and a pre-tightening screw (8). The lower ends of the first pre-tightening plate (4) and the second pre-tightening plate (9) are fixed to both ends of the motor base (1) in the y-axis direction. The upper parts of the first pre-tightening plate (4) and the second pre-tightening plate (9) are provided with threaded holes. The pre-tightening screw (8) passes through the threaded holes and is fixed by a nut. When working, when the piezoelectric sheet (2) is supplied with a sinusoidal excitation voltage of 90 to 360V, it drives the corresponding side of the motor stator (5) to vibrate, so that the motor drive foot (51) abuts against the linear slider (6), and drives the linear slider (6) to slide along the linear slide rail (7). A pair of motor drive feet can drive the linear slider (6) to move bidirectionally along the y-axis direction of the motor base (1). The lower end of the linear slide rail (7) is provided with a slide rail base plate (71), and a pair of waist-shaped holes (72) are provided on the slide rail base plate (71). The linear slide rail (7) is fixedly installed along the x-axis direction of the motor base (1) through the cooperation of the waist-shaped holes and bolts. A horizontally arranged dovetail groove is provided on one side of the linear slide rail (7). The corresponding side of the linear slider (6) is a dovetail slide platform. The dovetail slide platform is fitted in the dovetail groove so that the linear slider (6) slides along the direction of the linear slide rail (7). Each motor stator (5) is a horizontally arranged rectangular frame. The piezoelectric sheet (2) is fixedly connected to the inner side of the side frame corresponding to the linear slider (6). One end of the motor drive foot (51) is fixedly connected to the outer side of the side frame, so that the motor drive foot (51) is arranged horizontally and makes contact with the linear slider (6) at an angle of 45°~75°. A first pre-tightening plate (4) is provided on the L-shaped support plate (3) corresponding to the rear side of the motor stator (5) via a first horizontal base plate, so that the first pre-tightening plate (4) abuts against the rear frame of the pair of motor stators (5); The second pre-tightening plate (9) is installed upright on the motor base (1) through the second horizontal base plate, so that the second pre-tightening plate (9) abuts against the side of the linear slide rail (7) away from the pair of motor stators. The pre-tightening screw (8) passes through the threaded hole and is fixed by the nut, so that the pre-tightening screw (8) and the y-axis direction of the motor base (1) are parallel. Adjusting the preload screw (8) can apply clamping force to the first preload plate (4) and the second preload plate (9), thereby achieving vertical preload fixing when a pair of motor drive feet and linear slider (6) are in inclined contact.

2. The bidirectional drive linear piezoelectric motor according to claim 1, characterized in that: The motor stator (5) is fixedly installed at one end of the motor base (1) in the y-axis direction by an inverted L-shaped support plate (3). The vertical plate of the L-shaped support plate (3) is fixedly connected to one end of the motor base (1) in the y-axis direction. A pair of motor stators are fixedly installed on the upper end of the horizontal plate of the L-shaped support plate (3), so that the front side frame of the rectangular frame and the linear slider (6) are arranged parallel and correspondingly. The piezoelectric sheet (2) is fixedly connected to the inner side of the front side frame, and one end of the motor drive foot (51) is fixedly connected to the outer side of the front side frame.

3. The bidirectional drive linear piezoelectric motor according to claim 1, characterized in that: The pair of piezoelectric elements are made of piezoelectric ceramic PZT-4, and the pair of motor stators are made of carbon structural steel.

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