CN111541396A - A thin film piezoelectric motor integrating a piezoelectric thin film chip and a reducer - Google Patents

Abstract

The invention discloses a thin-film piezoelectric motor integrating a piezoelectric thin-film chip and a reducer, comprising a piezoelectric thin-film chip, a set of rotor gears, a central gear and/or a ring gear; the piezoelectric thin-film chip includes A set of stators of a thin-film piezoelectric motor, the stator and the rotor platform at the bottom of the rotor gear form a rotary piezoelectric motor unit; the rotation axes of the rotor gear, the sun gear and/or the ring gear are parallel to each other and the axis positions are Fixed, any rotor gear meshes with the sun gear and/or the ring gear, the rotor gear rotates in the same direction, and the torque of the thin-film piezoelectric motor is output by the sun gear or the ring gear. The invention integrates the piezoelectric thin film chip and the reducer, makes full use of the potential of the piezoelectric thin film chip, and designs a novel thin film piezoelectric motor with large volume, large torque and high rotation precision.

Description

A thin film piezoelectric motor integrating a piezoelectric thin film chip and a reducer

technical field

The invention belongs to the technical field of micro-electromechanical systems (MEMS), and relates to a piezoelectric motor, in particular to a thin-film piezoelectric motor integrating a piezoelectric thin-film chip and a speed reducer.

Background technique

The piezoelectric motor is driven by the circuit to drive the piezoelectric material to vibrate and rub against the rotor. Therefore, piezoelectric motors have high torque density, large holding torque, high rotation accuracy, and good electromagnetic compatibility, and are widely used as various types of rotating platforms, equipped with precision devices.

Piezoelectric materials can be divided into bulk piezoelectric materials and thin-film piezoelectric materials according to their shape. Bulk piezoelectric materials are generally bulky, but cannot be finely machined and cannot be integrated with microelectronic processes. Thin-film piezoelectric materials can be precisely processed by microelectronic technology and integrated with microelectronic circuits, which is the key to ensuring the performance of piezoelectric motors and mass production. However, the volume of a single thin film piezoelectric motor cannot be made very large (because of the thin film material, the film is easy to break), resulting in a large torque density, but the total output torque of the thin film piezoelectric motor is small. This limits the application of thin-film piezoelectric motors in large-volume, high-torque directions.

The reducer is a device that meshes with each other through some gear structures to reduce the speed and increase the torque (and improve the rotation accuracy). The reducer composed of multiple gear sets can also amplify and combine multiple input torques together to output torque externally. The output torque acts on the rotating platform through a certain structure.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide an integrated thin-film piezoelectric motor, which utilizes the advantages of piezoelectric thin-film wafers to manufacture multiple small piezoelectric motor structures, combined with the speed reducer structure, to combine piezoelectric thin-film chips containing multiple small motor structures It is integrated with the gear set reducer structure to manufacture a thin film piezoelectric motor integrating piezoelectric thin film chip and reducer, which can amplify multiple input torques and combine them for output, which has the advantages of large output torque and high rotation accuracy.

In order to realize the above-mentioned purpose of the invention, the present invention adopts the following technical solutions:

A thin-film piezoelectric motor integrating a piezoelectric thin-film chip and a reducer is characterized in that, the thin-film piezoelectric motor includes a piezoelectric thin-film chip, a set of rotor gears, and a central gear and/or a ring gear; The piezoelectric thin-film chip includes a set of stator structures of thin-film piezoelectric motors, any of the rotor gears is frictionally connected to the corresponding stator structure through the rotor platform at the bottom, and the stator structure and the rotor platform form a rotary pressure. Electric motor unit; the rotor gear and the central gear are external gears, the inner gear is an internal gear, the rotation axes of the rotor gear and the central gear and/or the inner gear are parallel to each other and the axis positions are fixed, the rotor gear Intermeshing with the sun gear and/or the ring gear, the rotation direction of any rotor gear is the same, and the torque of the thin film piezoelectric motor is output by the sun gear or the ring gear.

Piezoelectric thin film wafers can use microelectronics to manufacture chips containing multiple piezoelectric motor units (small motor structures) in one device with guaranteed precision. The piezoelectric motor unit on the chip can cooperate with the rotor, and the piezoelectric motor unit vibrates under the drive of the circuit, and the rotor is driven to rotate by the friction force. The thin-film piezoelectric motor of the present invention integrates the piezoelectric thin-film chip and the reducer. Multiple piezoelectric motor units on one piezoelectric thin-film chip cooperate with the rotor gear, and friction generates multiple input torques and drives the rotor gear. Rotation, multiple input torques are amplified and combined by the gear set (reducer) and output torque on the central gear or ring gear, thereby obtaining a new type of thin film piezoelectric motor with volume expansion, large torque and high rotation accuracy.

In the thin film piezoelectric motor, the tooth profile of the rotor gear, the central gear and/or the ring gear may adopt spur teeth or helical teeth at the same time.

In the thin-film piezoelectric motor of the present invention, in the case of including a sun gear, the sun gear can selectively generate or not generate an input torque. When the sun gear generates an input torque, a stator structure added on the piezoelectric thin film chip forms a piezoelectric motor unit with the rotor platform of the sun gear, and the rotation direction of the sun gear is opposite to the rotor gear.

The thin-film piezoelectric motor of the present invention can adopt one of the following various structural modes according to the input and output modes of torque:

The thin film piezoelectric motor includes a set of rotor gears and a central gear, any of the rotor gears and the central gear are meshed with each other, the rotor gear generates an input torque, and the torque is output from the central gear through the gear meshing;

The thin-film piezoelectric motor includes a set of rotor gears and an inner gear, any one of the rotor gears and the inner gear are meshed with each other, the rotor gear generates an input torque, and the torque is output from the inner gear through the gear meshing;

The thin film piezoelectric motor includes a set of rotor gears, a central gear and an inner gear, the central gear and the inner gear are coaxial, any one of the rotor gears meshes with the central gear and the inner gear, and the rotor gear generates an input. The torque is output from the central gear through the gear meshing, and the function of the ring gear is to improve the stability of the gear set reducer.

The thin film piezoelectric motor includes a set of rotor gears, a central gear and an inner gear, the central gear and the inner gear are coaxial, any one of the rotor gears meshes with the central gear and the inner gear, and the rotor gear generates an input. The torque is output from the ring gear through gear meshing. The sun gear can either improve the stability of the gear set reducer, or can selectively make the sun gear generate or not generate input torque. If the sun gear produces an input torque, the sun gear rotates in the opposite direction to the rotor gear.

Preferably, in the thin film piezoelectric motor, any piezoelectric motor unit has the same structure.

Preferably, in the thin film piezoelectric motor, the number of rotor gears is more than three, and the parameters of each rotor gear are the same, and the axis of the rotating shaft is centered on the axis of the central gear or the ring gear, etc. Arranged from a circle.

In the thin film piezoelectric motor of the present invention, the rotor gears are not limited to one-stage arrangement, and the rotor gears can be arranged in multiple stages. The technical scheme of the multi-stage arrangement of rotor gears is the same as the one-stage arrangement, each rotor gear corresponds to a piezoelectric motor unit on the piezoelectric film chip, wherein the rotor gears of two adjacent stages mesh with each other and rotate in opposite directions. The first stage rotor gear intermesh with the sun gear (if any), and the last stage rotor gear intermesh with the ring gear (if any). Preferably, the parameters of the rotor gears of the same stage are all the same, and their axes are arranged in an equidistant circle with the center of the center gear or the ring gear as the center. The scheme of multi-stage arrangement of rotor gears is more compact, can more effectively utilize the potential of piezoelectric thin film chips, and greatly expand the piezoelectric motor unit in space. Under the same device volume, the multi-stage arrangement of rotor gears has a larger output torque.

Beneficial effects of the present invention:

(1) The organic integration of the piezoelectric thin film chip and the reducer forms a new type of thin film piezoelectric motor with large volume, large torque and high rotation accuracy.

(2) Wide application range and flexible design. The motor scheme can be flexibly designed according to the needs of the application and the limitation of manufacturing processing capacity.

(3) The structure is compact, and the potential of the piezoelectric thin film chip is fully utilized.

(4) The symmetry is good, which is beneficial to the stability of the device structure.

Description of drawings

FIG. 1 is a schematic structural diagram of a single thin-film piezoelectric motor;

FIG. 2 is a schematic diagram of the first structural mode of the thin-film piezoelectric motor of the present invention;

3 is a schematic diagram of a second structure of the thin-film piezoelectric motor of the present invention;

4 is a schematic diagram of a third structural mode of the thin-film piezoelectric motor of the present invention;

5 is a schematic diagram of a fourth structural mode of the thin-film piezoelectric motor of the present invention;

6 is a perspective view of the thin-film piezoelectric motor of the structure of FIG. 3 of the present invention;

7 is an exploded view of the thin-film piezoelectric motor of the structure of FIG. 3 of the present invention;

FIG. 8 is a schematic diagram of the structure of the two-stage arrangement of the rotor gears of the thin-film piezoelectric motor of the present invention;

In the picture: 1- central gear, 2-rotor gear, 3-ring gear, 4-nut, 5-upper support frame, 7-bearing, 8-piezoelectric film chip, 9-lower support frame, 10-bolt, 11-rotor (rotor platform), 12-stator (piezoelectric film material), 13-support structure.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments. It should be understood that the specific embodiments described below are only used to explain the present invention, but not to limit the present invention. The protection scope of the present invention is not limited by the specific embodiments, but is determined by the claims.

As shown in FIG. 1, a single rotary motion type thin-film piezoelectric motor usually includes a stator 12 made of piezoelectric thin-film material, and a rotor 11 (rotor platform) frictionally coupled with the stator 12. The stator 12 vibrates under the action of the driving circuit, and uses Friction makes the rotor spin. The required stator can be easily fabricated using piezoelectric thin-film chips.

The thin-film piezoelectric motor integrating piezoelectric thin-film chip and reducer of the present invention includes a piezoelectric thin-film chip 8 and a set of rotor gears 2 . The stator, the contact surface between the rotor gear 2 and the stator includes a rotor platform (friction material), and the rotor platform of the rotor gear 2 is frictionally coupled with the stator to form a rotary motion piezoelectric motor unit similar to the structure in FIG. 1 .

The thin film piezoelectric motor further includes a central gear 1 or an inner gear 3 , or has both the central gear 1 and the inner gear 3 . The rotor gear 2 is meshed with the sun gear 1 and/or the ring gear 3, any rotor gear 2 rotates in the same direction, and the torque of the film piezoelectric motor is output by the sun gear 1 or the ring gear 3.

In the thin film piezoelectric motor of the present invention, the rotor gear 2 and the central gear 1 are external gears, and the inner gear 3 is an internal gear, and their tooth shapes can adopt spur teeth or helical teeth at the same time. The rotation axes of the rotor gear 2 , the central gear 1 and/or the ring gear 3 are parallel to each other, and the axis positions are fixed by the bearing 4 .

The principle of the above structure is as follows: a plurality of piezoelectric motor unit structures on the chip 8 of the piezoelectric motor cooperate with the rotor gear 2 to rub against each other to generate a plurality of input torques and drive the rotor gear 2 to rotate. Normally, the piezoelectric motor unit structure The number is the same as the number of rotor gears 2. After the multiple input torques are amplified and combined by the gear set reducer, the torque is output in the sun gear 1 or the ring gear 3 . The output torque is output through a certain structure, so as to obtain a new type of thin-film piezoelectric motor with large volume, large torque and high rotation accuracy.

The number of rotor gears 2 can be greater than or equal to three in the film piezoelectric motor integrating piezoelectric film chip and reducer of the present invention. It is recommended that the parameters of each rotor gear 2 be the same, that is, have the same size, number of teeth, rotational speed, etc., The corresponding piezoelectric motor units have the same structure. The axis of the rotating shaft of the rotor gear 2 is arranged in an equidistant circle with the axis of the central gear 1 or the ring gear 3 as the center.

2 to 5 (the piezoelectric thin-film chip 8 and the rotor platform are omitted in the drawings), according to the input and output modes of torque, the preferred implementation modes of the thin-film piezoelectric motor of the present invention are divided into four categories for detailed description. . In the following description, the rotor gear set is taken as an example of rotor gears 2 having three identical parameters, the same rotation direction, and an equidistant circumferential arrangement.

The first solution is shown in FIG. 2 , the thin-film piezoelectric motor includes a piezoelectric thin-film chip 8 , a set of rotor gears 2 , a central gear 1 and an inner gear 3 . The piezoelectric film chip 8 includes a set of stator structures corresponding to the rotor gear 2 , and any stator structure and the rotor platform of the corresponding rotor gear 2 form a piezoelectric motor unit with the same structure. The center gear 1 and the ring gear 3 are coaxial, and any rotor gear 2 meshes with the center gear 1 and the ring gear 3. The rotor gear 2 generates input through the friction of the piezoelectric motor unit on the piezoelectric film chip 8. The torque is output from the central gear 1 through gear meshing, and the function of the ring gear 3 is to improve the stability of the gear set reducer.

FIG. 3 shows the second technical solution. The thin-film piezoelectric motor includes a piezoelectric thin-film chip 8 , a set of rotor gears 2 , a central gear 1 and an inner gear 3 . The piezoelectric thin film chip 8 includes a set of stator structures corresponding to the rotor gear 2 , and any stator structure and the rotor platform of the corresponding rotor gear 2 form a piezoelectric motor unit. The center gear 1 and the ring gear 3 are coaxial, and any rotor gear 2 meshes with the center gear 1 and the ring gear 3. The rotor gear 2 generates input torque and outputs torque from the ring gear 3 through gear meshing. The sun gear 1 can not only improve the stability of the gear set reducer, but also selectively allow the sun gear 1 to generate or not generate an input torque. If the sun gear 1 generates an input torque, the piezoelectric film chip 8 includes a stator structure corresponding to the sun gear 1, and the sun gear 1 has the same parameters as the rotor gear 2, and the rotation direction is opposite.

Figures 4 and 5 show two solutions with more simplified structures. On the premise of ensuring the stability of the reducer, the central gear 1 or the inner gear 3 is omitted from the structure.

The thin-film piezoelectric motor shown in FIG. 4 includes a set of rotor gears 2 and a central gear 1. Any rotor gear 2 meshes with the central gear 1. The rotor gear 2 generates an input torque and outputs torque from the central gear 1 through gear meshing. .

The thin-film piezoelectric motor shown in FIG. 5 includes a set of rotor gears 2 and a ring gear 3. Any rotor gear 2 meshes with the ring gear 3. The rotor gear 2 generates an input torque, and the gear meshes from the ring gear through the gear meshing. 3 Output torque.

A specific embodiment of a thin-film piezoelectric motor integrating a piezoelectric thin-film chip and a reducer shown in FIG. 3 is shown in FIG. 6 and FIG. 7 , including a piezoelectric thin-film chip 8 (including a stator structure), a central gear 1 , and a rotor gear 2 , The ring gear 3 is assembled from the bearing 7, the upper support frame 5, the lower support frame 9, the bolts 10 and the nuts 4, etc.

The specific structure of the thin-film piezoelectric motor described in the above-mentioned Figures 2 to 5, wherein the rotor gears are only arranged in one stage, and the thin-film piezoelectric motor integrating the piezoelectric thin-film chip and the reducer of the present invention can also adopt a multi-stage arrangement. Rotor gear, in order to more effectively utilize the potential of piezoelectric thin film chip, the structure of thin film piezoelectric motor is more compact, and the output torque is larger. The same as the one-stage arrangement of rotor gears, in the scheme of multi-stage arrangement of rotor gears, each rotor gear corresponds to the piezoelectric motor unit on the piezoelectric film chip, and is equally spaced around the circumference. The rotor gears of two adjacent stages mesh with each other and rotate in opposite directions. The first stage rotor gear meshes with the sun gear (if any), and the last stage rotor gear meshes with the ring gear (if any).

As shown in FIGS. 2 to 5 , the scheme of the multi-stage arrangement of the rotor gears can also be divided into a variety of different structural forms according to the torque input and output modes, which are not listed one by one here. Figure 8 is one of the two-stage arrangement of rotor gears. The torque input and output method is similar to the structure shown in Figure 2, including two-stage rotor gear 2, sun gear 1 and ring gear 3. The rotor in Figure 2 The gears 2 are expanded into two-stage rotor gears 2 with the same parameters, and the same-stage rotor gears 2 are arranged in an equidistant circle with the axis of the central gear 1 (ring gear 3 ) as the center. The first-stage rotor gear 2 meshes with the sun gear 1, the first-stage and second-stage rotor gears 2 mesh with each other, the second-stage rotor gear 2 meshes with the ring gear 3, and the first-stage and second-stage rotor gears 2 mesh with each other. The rotor gear 2 rotates in the opposite direction, and the sun gear 1 outputs torque.

Claims (10)

1. A thin-film piezoelectric motor integrating piezoelectric thin-film chip and reducer, wherein the thin-film piezoelectric motor comprises piezoelectric thin-film chip (8), a group of rotor gears (2), and a central gear (1) and/or the ring gear (3); the piezoelectric thin-film chip (8) includes a set of stator structures of the thin-film piezoelectric motor, and any of the rotor gears (2) passes through the rotor platform at the bottom Frictionally connected with the corresponding stator structure, the stator structure and the rotor platform form a rotary piezoelectric motor unit; the rotor gear (2) and the central gear (1) are external gears, and the ring gear is an internal gear (3). ), the rotating shafts of the rotor gear (2) and the central gear (1) and/or the inner gear (3) are parallel to each other and the position of the shaft center is fixed, and the rotor gear (2) and the central gear (1) and/or The inner gears (3) are meshed with each other, the rotation directions of any rotor gears (2) are the same, and the torque of the thin film piezoelectric motor is output by the central gear (1) or the inner gear (3). 2. The thin-film piezoelectric motor according to claim 1, wherein the thin-film piezoelectric motor comprises a central gear (1), a stator structure on the piezoelectric thin-film chip (8) and the central gear (1) The rotor platform of the piezo motor unit is formed, and the sun gear (1) rotates in the opposite direction to the rotor gear (2). 3. The thin-film piezoelectric motor according to claim 1, wherein the thin-film piezoelectric motor comprises a set of rotor gears (2) and a central gear (1), any rotor gear (2) and the central gear (1) Intermeshing with each other, the rotor gear (2) generates input torque, and outputs torque from the central gear (1) through gear meshing. 4. The thin-film piezoelectric motor according to claim 1, characterized in that, the thin-film piezoelectric motor comprises a set of rotor gears (2) and an inner ring gear (3), and any rotor gear (2) is connected to the inner gear (3). The ring gear (3) meshes with each other, the rotor gear (2) generates an input torque, and the torque is output from the inner ring gear (3) through the gear meshing. 5. The thin-film piezoelectric motor according to claim 1, wherein the thin-film piezoelectric motor comprises a set of rotor gears (2), a central gear (1) and an inner gear (3), and a central gear ( 1) Coaxial with the ring gear (3), any rotor gear (2) meshes with the center gear (1) and the ring gear (3), and the rotor gear (2) generates an input torque, which is transmitted from the center gear through gear meshing. (1) Output torque. 6. The thin-film piezoelectric motor according to claim 1, characterized in that, the thin-film piezoelectric motor comprises a set of rotor gears (2), a central gear (1) and a ring gear (3), and a central gear ( 1) Coaxial with the ring gear (3), any rotor gear (2) meshes with the central gear (1) and the ring gear (3), the rotor gear (2) generates an input torque, Ring (3) outputs torque. 7 . The thin-film piezoelectric motor according to claim 1 , wherein any piezoelectric motor unit in the thin-film piezoelectric motor has the same structure. 8 . 8. The thin-film piezoelectric motor according to claim 1, characterized in that, there are more than three rotor gears (2), and each rotor gear (2) has the same parameters, and the axis of its rotating shaft is The center gear (1) or the inner gear (3) is arranged in an equidistant circle with the axis as the center. 9 . The thin-film piezoelectric motor according to claim 1 , wherein the rotor gears ( 2 ) are arranged in multiple stages, wherein the rotor gears ( 2 ) of two adjacent stages mesh with each other and rotate in opposite directions. 10 . , the first stage rotor gear (2) meshes with the central gear (1), and/or the last stage rotor gear (2) meshes with the ring gear (3). 10. The thin-film piezoelectric motor according to claim 9, characterized in that the rotor gears (2) of the same stage have the same parameters, and the axis of which is centered on the axis of the central gear (1) or the ring gear (3) Arranged in equidistant circles.

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