A planar universal micro piezoelectric motor

Abstract

The present invention provides a planar universal micro piezoelectric motor, belonging to the technical field of micro piezoelectric motors. The piezoelectric motor adopts four identical micro piezoelectric drive elements arranged symmetrically in a square manner on the same plane. Each micro piezoelectric drive element can realize bidirectional motion, and the micro piezoelectric drive element can be controlled individually. The micro piezoelectric drive element and the driven component are tightly fitted by pre-stressed spring sheets, and a universal guide structure is formed by the cooperation of universal grooves and balls to realize auxiliary motion in all directions within the plane. By cooperatively controlling the movement directions of the four micro piezoelectric drive elements, rotation, linear or interpolation motion is realized. The present invention meets the demand of longitudinally narrow installation space. The micro piezoelectric drive element is simultaneously excited to produce a driving mode when the piezoelectric motor is driven, which can provide a large thrust. At the same time, the present invention has a compact structure and a stable output, which significantly improves the driving performance and large stroke stability of the piezoelectric motor.

Description

Technical Field

[0001] The invention belongs to the technical field of micro piezoelectric motors, and in particular relates to a planar universal micro piezoelectric motor. Background Art

[0002] Piezoelectric motors have the characteristics of compact structure, low speed and high torque, no electromagnetic interference, and high displacement resolution. They are particularly suitable for driving precision instruments. They are necessary components in electromechanical systems such as fuze switches, inertial navigation, precision positioning, flight acceleration control, and acoustic energy conversion. They are widely used in precision engineering fields such as aerospace, weapons and equipment.

[0003] With the development of science and technology, the performance requirements of piezoelectric devices in various application fields are constantly increasing, requiring piezoelectric motors to have multi-directional motion functions, miniaturized size, low-voltage drive, and large torque output. For example, the anti-shake movement of mobile phone precision lenses, the multi-degree-of-freedom movement of micro-displacement stages, and the precision movement of micro-flying robots require piezoelectric motors to have functions such as linear motion, rotational motion, and circular interpolation motion at the same time. However, traditional piezoelectric motor vibrators can only achieve pure linear motion or pure rotational motion, and cannot meet the needs of multi-directional motion at the same time. Moreover, the current size of piezoelectric motors and their driving voltage are relatively large, making it difficult to achieve miniaturization and unable to meet actual use requirements. Summary of the invention

[0004] In order to solve the problems existing in the prior art, the present invention provides a planar universal micro piezoelectric motor, which is small in size and can have multiple motion forms such as linear, rotational, interpolation, etc., and can realize planar universal motion. The motor is composed of a cooperative bracket and four micro piezoelectric drive elements. The driving mode of the micro piezoelectric drive element is obtained by applying a voltage of a specific frequency to the micro piezoelectric drive element, which can enable a single micro piezoelectric drive element to achieve bidirectional linear motion. The micro piezoelectric drive element and the driven component are tightly fitted by pre-stressing the spring sheet, and a universal guide structure is formed by the cooperation of the universal groove and the ball to realize auxiliary motion in all directions in the plane. By cooperatively controlling the movement direction of the four micro piezoelectric drive elements, the rotation, linear or interpolation motion of the piezoelectric motor can be realized.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] A planar universal micro piezoelectric motor comprises an upper end cover 1, a ball 2, a mover 3, a micro piezoelectric drive group 4, a cooperative bracket 5, a pre-stressed spring sheet 6 and a frame 7.

[0007] The upper end cover 1 and the frame 7 form the outer shell of the planar universal micro piezoelectric motor, in which the ball 2, the mover 3, the micro piezoelectric drive group 4, the cooperative bracket 5 and the preload spring 6 are installed in sequence from top to bottom. The cooperative bracket 5 is a square thin plate structure, located on the frame 7; a preload spring 6 is provided between the cooperative bracket 5 and the frame 7.

[0008] The micro piezoelectric drive group 4 includes four micro piezoelectric drive elements, namely a first micro piezoelectric drive element 8, a second micro piezoelectric drive element 9, a third micro piezoelectric drive element 10 and a fourth micro piezoelectric drive element 11. The four micro piezoelectric drive elements are all connected to the cooperative bracket 5 and are symmetrically arranged in a square manner on the same plane, and each micro piezoelectric drive element corresponds to a corner of the cooperative bracket 5.

[0009] The micro piezoelectric driving element comprises an elastic body 12, a lower electrode 13, a piezoelectric body 14 and a partitioned upper electrode 15. The upper surface of the elastic body 12 is uniformly distributed with tooth-shaped structures, and the lower surface is provided with the lower electrode 13, the piezoelectric body 14 and the partitioned upper electrode 15 in sequence.

[0010] The mover 3 is in contact with the micro piezoelectric drive group 4 under the action of the pre-pressure provided by the pre-pressure spring sheet 6 .

[0011] The balls 2 are installed in four universal grooves on the upper end cover 1, and the balls 2 are in contact with the mover 3 to achieve multi-directional guided movement of the mover.

[0012] By applying different voltages to the piezoelectric body of the micro piezoelectric drive element, bidirectional motion of a single micro piezoelectric drive element can be achieved. The micro piezoelectric drive element can be controlled individually, and can also achieve linear, rotational and interpolation motion of the mover through coordinated control.

[0013] The beneficial effects of the present invention are:

[0014] (1) The present invention has multiple movements such as rotation, linear or interpolation, and can meet the needs of multi-directional movement in a plane.

[0015] (2) The present invention utilizes the clearance fit between the ball and the universal groove to achieve multi-directional guided movement of the mover, and at the same time converts the friction between the mover and the upper end cover into rolling friction, thereby ensuring stability and high thrust.

[0016] (3) The present invention is a micro-thin plate structure, and the longitudinal dimension of the micro-piezoelectric driving element is less than 1 mm, which can meet the needs of narrow longitudinal installation space and solve the problem that traditional piezoelectric motors are not applicable due to their large size.

[0017] (4) The four micro piezoelectric drive elements used in the present invention are simultaneously excited to produce a driving mode when the piezoelectric motor is driven, which can provide a large thrust or rotational torque, solving the problem of insufficient driving force of conventional piezoelectric motors. At the same time, the four micro piezoelectric drive elements of the present invention are symmetrically arranged, compact in structure, and contact with the mover at multiple points, and their output is stable, which significantly improves the driving performance and large stroke stability of the piezoelectric motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 3D schematic diagram of a planar universal micro piezoelectric motor in an embodiment.

[0019] Figure 2 It is a three-dimensional schematic diagram of the upper end cover of the planar universal micro piezoelectric motor in the embodiment.

[0020] Figure 3 Schematic diagram of the guide of the mover of the planar universal micro piezoelectric motor in the embodiment.

[0021] Figure 4 Schematic diagram of pre-tightening of the planar universal micro piezoelectric motor in the embodiment.

[0022] Figure 5 Schematic diagram of the micro piezoelectric drive group in the embodiment.

[0023] Figure 6 3D schematic diagram of a micro piezoelectric driving element in the embodiment.

[0024] Figure 7 Schematic diagram of the planar universal micro piezoelectric motor in the embodiment moving linearly along the X direction.

[0025] Figure 8 Schematic diagram of the planar universal micro piezoelectric motor in the embodiment moving linearly along the Y direction.

[0026] Fig. 9 Schematic diagram of the clockwise rotation movement of the planar universal micro piezoelectric motor in the embodiment.

[0027] Fig.10 Schematic diagram of the counterclockwise rotation movement of the planar universal micro piezoelectric motor in the embodiment.

[0028] Fig.11 Schematic diagram of the interpolation motion of the planar universal micro piezoelectric motor in the embodiment.

[0029] In the figure: 1 upper end cover; 2 ball bearing; 3 mover; 4 micro piezoelectric drive group; 5 cooperative bracket; 6 pre-loaded spring; 7 frame; 8 first micro piezoelectric drive element; 9 second micro piezoelectric drive element; 10 third micro piezoelectric drive element; 11 fourth micro piezoelectric drive element; 12 elastic body; 13 lower electrode; 14 piezoelectric body; 15 partitioned upper electrode; 16 universal slot A; 17 universal slot B; 18 universal slot C; 19 universal slot D. DETAILED DESCRIPTION

[0030] The present invention is further described in conjunction with the technical scheme and the accompanying drawings.

[0031] like Figure 1-6 As shown, the planar universal micro piezoelectric motor of this embodiment includes, from top to bottom, an upper end cover 1, a ball 2, a mover 3, a micro piezoelectric drive group 4, a cooperative bracket 5, a pre-stressed spring 6 and a frame 7.

[0032] The upper end cover 1 and the frame 7 form the outer shell of the planar universal micro piezoelectric motor. The cooperative bracket 5 is a square thin plate structure, located on the frame 7, and a pre-stressed spring sheet 6 is arranged between the two.

[0033] The micro piezoelectric drive group 4 includes a first micro piezoelectric drive element 8, a second micro piezoelectric drive element 9, a third micro piezoelectric drive element 10 and a fourth micro piezoelectric drive element 11. The four micro piezoelectric drive elements are symmetrically arranged in a square manner on the cooperative bracket 5, and are in direct contact with the mover 3 under a certain pre-pressure, and the pre-pressure is achieved by adjusting the pre-pressure spring 6. The micro piezoelectric drive group 4 is the first micro piezoelectric drive element 8, the third micro piezoelectric drive element 10, the fourth micro piezoelectric drive element 11 and the second micro piezoelectric drive element 9 in the clockwise direction.

[0034] The micro piezoelectric driving element comprises an elastic body 12, a lower electrode 13, a piezoelectric body 14 and a partitioned upper electrode 15. The upper surface of the elastic body 12 is uniformly distributed with tooth-shaped structures, and the lower surface is provided with the lower electrode 13, the piezoelectric body 14 and the partitioned upper electrode 15 in sequence.

[0035] Under certain excitation, the piezoelectric body 14 of the micro piezoelectric drive element transmits motion to the mover 3 through the toothed structure on the elastic body 12. The multi-directional guided motion of the mover is achieved through the cooperation between the ball 2 and the universal grooves (universal groove A16, universal groove B17, universal groove C18, universal groove D19) on the upper end cover 1.

[0036] like Figure 7-11 As shown, the specific implementation of the embodiment is as follows:

[0037] 1. Realization of linear motion of planar universal micro piezoelectric motor

[0038] By applying voltage to the piezoelectric body 14 of the first micro piezoelectric driving element 8 and the second micro piezoelectric driving element 9 to stimulate the forward driving mode of the micro piezoelectric driving element, and at the same time applying voltage to the piezoelectric body 14 of the third micro piezoelectric driving element 10 and the fourth micro piezoelectric driving element 11 to stimulate the reverse driving mode of the micro piezoelectric driving element, under the joint action of the four micro piezoelectric driving elements, the planar universal micro piezoelectric motor realizes X-direction linear motion, as shown in 7; by applying voltage to the piezoelectric body 14 of the first micro piezoelectric driving element 8 and the third micro piezoelectric driving element 10 to stimulate the forward driving mode of the micro piezoelectric driving element, and at the same time applying voltage to the piezoelectric body 14 of the second micro piezoelectric driving element 9 and the fourth micro piezoelectric driving element 11 to stimulate the reverse driving mode of the micro piezoelectric driving element, under the joint action of the four micro piezoelectric driving elements, the planar universal micro piezoelectric motor realizes Y-direction linear motion, as shown in 8.

[0039] 2. Realization of the rotational motion of the planar universal micro piezoelectric motor

[0040] By applying voltage to the piezoelectric bodies 14 of the first micro piezoelectric driving element 8 and the fourth micro piezoelectric driving element 11 to stimulate the forward driving mode of the micro piezoelectric driving element, and applying voltage to the piezoelectric bodies 14 of the second micro piezoelectric driving element 9 and the third micro piezoelectric driving element 10 to stimulate the reverse driving mode of the micro piezoelectric driving element, under the joint action of the four micro piezoelectric driving elements, the planar universal micro piezoelectric motor realizes clockwise rotation motion, such as Fig. 9 As shown; by applying voltage to the piezoelectric body 14 of the first micro piezoelectric driving element 8 and the fourth micro piezoelectric driving element 11 to stimulate the reverse driving mode of the micro piezoelectric driving element, and applying voltage to the piezoelectric body 14 of the second micro piezoelectric driving element 9 and the third micro piezoelectric driving element 10 to stimulate the forward driving mode of the micro piezoelectric driving element, under the joint action of the four micro piezoelectric driving elements, the planar universal micro piezoelectric motor realizes counterclockwise rotation motion, as shown Fig.10 shown.

[0041] 3. Realization of interpolation motion of planar universal micro piezoelectric motor

[0042] By applying voltage to the piezoelectric bodies 14 of the first micro piezoelectric driving element 8 and the second micro piezoelectric driving element 9 to stimulate the reverse driving mode of the micro piezoelectric driving element, and applying voltage to the piezoelectric bodies 14 of the third micro piezoelectric driving element 10 and the fourth micro piezoelectric driving element 11 to stimulate the forward driving mode of the micro piezoelectric driving element, respectively adjusting the voltage amplitudes between the first micro piezoelectric driving element 8, the second micro piezoelectric driving element 9, the third micro piezoelectric driving element 10 and the fourth micro piezoelectric driving element 11, under the coordinated action of the four micro piezoelectric driving elements, the planar universal micro piezoelectric motor realizes interpolation motion, such as Fig.11shown.

Claims

1. A planar universal micro piezoelectric motor, characterized in that: The motor comprises an upper end cover (1), a ball (2), a mover (3), a micro piezoelectric drive group (4), a cooperative bracket (5), a pre-stressed spring sheet (6) and a frame (7); The upper end cover (1) and the frame (7) form the outer shell of the planar universal micro piezoelectric motor; the cooperative bracket (5) is a square thin plate structure, located on the frame (7), and a pre-stressed spring sheet (6) is provided between the two; The micro piezoelectric drive group (4) comprises four micro piezoelectric drive elements, namely a first micro piezoelectric drive element (8), a second micro piezoelectric drive element (9), a third micro piezoelectric drive element (10) and a fourth micro piezoelectric drive element (11); the four micro piezoelectric drive elements are all connected to the cooperative bracket (5) and are symmetrically arranged in a square manner on the same plane, and each micro drive element corresponds to a corner of the cooperative bracket (5); The mover (3) contacts the micro piezoelectric drive group (4) under the action of the preload provided by the preload spring sheet (6); the ball (2) is installed in the universal groove on the upper end cover (1), and the ball (2) contacts the mover (3) to achieve multi-directional guided movement of the mover; The micro piezoelectric drive element realizes bidirectional motion of a single micro piezoelectric drive element by applying different voltages; and the micro piezoelectric drive element can be controlled individually, and can also realize linear, rotational and interpolation motion of the mover through coordinated control; The micro piezoelectric drive element comprises an elastic body (12), a lower electrode (13), a piezoelectric body (14) and a partitioned upper electrode (15); wherein the upper surface of the elastic body (12) is evenly distributed with tooth-shaped structures, and the lower surface is provided with the lower electrode (13), the piezoelectric body (14) and the partitioned upper electrode (15) in sequence.

2. The planar universal micro piezoelectric motor according to claim 1, characterized in that: The micro-piezoelectric drive group (4) comprises, in a clockwise direction, a first micro-piezoelectric drive element (8), a third micro-piezoelectric drive element (10), a fourth micro-piezoelectric drive element (11) and a second micro-piezoelectric drive element (9); By applying voltage to the piezoelectric bodies (14) of the first micro-piezoelectric driving element (8) and the second micro-piezoelectric driving element (9) to stimulate the forward driving mode of the micro-piezoelectric driving element, and simultaneously applying voltage to the piezoelectric bodies (14) of the third micro-piezoelectric driving element (10) and the fourth micro-piezoelectric driving element (11) to stimulate the reverse driving mode of the micro-piezoelectric driving element, the planar universal micro-piezoelectric motor realizes X-direction linear motion under the joint action of the four micro-piezoelectric driving elements; By applying voltage to the piezoelectric bodies (14) of the first micro piezoelectric driving element (8) and the third micro piezoelectric driving element (10), the forward driving mode of the micro piezoelectric driving element is stimulated, and by applying voltage to the piezoelectric bodies (14) of the second micro piezoelectric driving element (9) and the fourth micro piezoelectric driving element (11), the reverse driving mode of the micro piezoelectric driving element is stimulated. Under the joint action of the four micro piezoelectric driving elements, the planar universal micro piezoelectric motor realizes Y-direction linear motion.

3. A planar universal micro piezoelectric motor according to claim 1 or 2, characterized in that: The micro-piezoelectric drive group (4) comprises, in a clockwise direction, a first micro-piezoelectric drive element (8), a third micro-piezoelectric drive element (10), a fourth micro-piezoelectric drive element (11) and a second micro-piezoelectric drive element (9); By applying voltage to the piezoelectric bodies (14) of the first micro-piezoelectric driving element (8) and the fourth micro-piezoelectric driving element (11), a forward driving mode of the micro-piezoelectric driving element is stimulated, and at the same time, by applying voltage to the piezoelectric bodies (14) of the second micro-piezoelectric driving element (9) and the third micro-piezoelectric driving element (10), a reverse driving mode of the micro-piezoelectric driving element is stimulated. Under the joint action of the four micro-piezoelectric driving elements, the planar universal micro-piezoelectric motor realizes clockwise rotational motion; By applying voltage to the piezoelectric bodies (14) of the first micro piezoelectric driving element (8) and the fourth micro piezoelectric driving element (11), the reverse driving mode of the micro piezoelectric driving element is stimulated, and by applying voltage to the piezoelectric bodies (14) of the second micro piezoelectric driving element (9) and the third micro piezoelectric driving element (10), the forward driving mode of the micro piezoelectric driving element is stimulated. Under the joint action of the four micro piezoelectric driving elements, the planar universal micro piezoelectric motor realizes counterclockwise rotation.

4. The planar universal micro piezoelectric motor according to claim 2, characterized in that: The micro-piezoelectric drive group (4) comprises, in a clockwise direction, a first micro-piezoelectric drive element (8), a third micro-piezoelectric drive element (10), a fourth micro-piezoelectric drive element (11) and a second micro-piezoelectric drive element (9); By applying voltage to the piezoelectric bodies (14) of the first micro-piezoelectric driving element (8) and the fourth micro-piezoelectric driving element (11), a forward driving mode of the micro-piezoelectric driving element is stimulated, and at the same time, by applying voltage to the piezoelectric bodies (14) of the second micro-piezoelectric driving element (9) and the third micro-piezoelectric driving element (10), a reverse driving mode of the micro-piezoelectric driving element is stimulated. Under the joint action of the four micro-piezoelectric driving elements, the planar universal micro-piezoelectric motor realizes clockwise rotational motion; By applying voltage to the piezoelectric bodies (14) of the first micro piezoelectric driving element (8) and the fourth micro piezoelectric driving element (11), the reverse driving mode of the micro piezoelectric driving element is stimulated, and by applying voltage to the piezoelectric bodies (14) of the second micro piezoelectric driving element (9) and the third micro piezoelectric driving element (10), the forward driving mode of the micro piezoelectric driving element is stimulated. Under the joint action of the four micro piezoelectric driving elements, the planar universal micro piezoelectric motor realizes counterclockwise rotation.

5. A planar universal micro piezoelectric motor according to claim 1, 2 or 4, characterized in that: The micro-piezoelectric drive group (4) comprises, in a clockwise direction, a first micro-piezoelectric drive element (8), a third micro-piezoelectric drive element (10), a fourth micro-piezoelectric drive element (11) and a second micro-piezoelectric drive element (9); By applying voltage to the piezoelectric bodies (14) of the first micro-piezoelectric driving element (8) and the second micro-piezoelectric driving element (9), a reverse driving mode of the micro-piezoelectric driving element is stimulated, and at the same time, by applying voltage to the piezoelectric bodies (14) of the third micro-piezoelectric driving element (10) and the fourth micro-piezoelectric driving element (11), a forward driving mode of the micro-piezoelectric driving element is stimulated, and the voltage amplitudes between the four micro-piezoelectric driving elements are adjusted respectively. Under the coordinated action of the four micro-piezoelectric driving elements, the planar universal micro-piezoelectric motor realizes interpolation motion.

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