A friction actuator based on conjugate curve mechanism and its working method

Abstract

The present invention discloses a friction actuator based on a conjugate curve mechanism and a working method thereof, comprising a rotor, two pressure plates, a rotating bracket, two actuators, two driving feet, two bearings, two rotating shafts and two springs, wherein the two actuators, two driving feet, the rotating bracket and one rotating shaft together constitute a driving module. The rotor and the driving module constitute a conjugate curve mechanism, the contour curve of the rotor is a conjugate curve, and the driving module can translate in the guide grooves of the two pressure plates and can rotate freely. Under the action of friction force, the two actuators work independently to drive the actuator to rotate in the forward and reverse directions respectively. The present invention has a simple structure, reliable control, and high positioning accuracy, and can be applied in fields such as optical fiber docking.

Description

Technical Field

[0001] The present invention relates to the technical field of micro motors, and in particular to a friction actuator based on a conjugate curve mechanism and a working method thereof. Background Art

[0002] Piezoelectric ceramic components are widely used in the aerospace field due to their fast response, high output, good environmental adaptability, and high precision. Currently, most rotary piezoelectric actuators based on the principles of inchworm motion and inertial impact have strict driver assembly requirements, complex structures, high manufacturing costs, and poor system adaptability in the presence of friction and wear. These factors hinder the widespread application of rotary piezoelectric actuators based on the inertial principle in actual production and daily life. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a friction actuator based on a conjugate curve mechanism and a working method thereof in view of the defects involved in the background technology.

[0004] The present invention adopts the following technical solutions to solve the above technical problems:

[0005] A friction actuator based on a conjugate curve mechanism includes a rotor, a first pressure plate, a second pressure plate, a rotating bracket, a first actuator, a second actuator, a first driving foot, a second driving foot, a first bearing, a second bearing, a first rotating shaft, a second rotating shaft, a first spring, and a second spring;

[0006] The rotor is strip-shaped and includes an upper end surface, a lower end surface and side walls, and the curves of the side wall contours on both sides of the rotor are symmetrical conjugate curves. A first bearing mounting hole is provided through the center of the upper end surface of the rotor;

[0007] The first pressing plate and the second pressing plate have the same structure, with one end of each plate provided with a guide groove along its length direction and the other end provided with a fixing hole; the first pressing plate and the second pressing plate are symmetrical about the straight line where the guide groove is located;

[0008] The rotating bracket is columnar and has a second bearing mounting hole extending through it along its axis.

[0009] The first actuator and the second actuator are both cylindrical piezoelectric stacks, symmetrically arranged, with one end of each being fixedly connected to the side wall of the rotating bracket and perpendicular to the axis of the rotating bracket;

[0010] The first driving foot and the second driving foot are respectively arranged at one end of the first actuator and the second actuator away from the rotating bracket;

[0011] The first bearing is disposed in the first bearing mounting hole, with its outer ring fixedly connected to the rotor and its inner ring fixedly connected to the first rotating shaft, and both ends of the first rotating shaft fixedly connected to the fixing holes on the first pressing plate and the second pressing plate, respectively, so that the rotor is located between the first pressing plate and the second pressing plate and can rotate freely;

[0012] The second rotating shaft is provided with a first annular groove and a second annular groove respectively matching the guide grooves of the first pressing plate and the second pressing plate;

[0013] The second bearing is arranged in the second bearing mounting hole, the outer ring of the second bearing is fixedly connected to the rotating bracket, and the inner ring is fixedly connected to the second rotating shaft, and the first annular groove and the second annular groove on the second rotating shaft are respectively matched with the first pressing plate and the second pressing plate guide groove, so that the rotating bracket is located between the first pressing plate and the second pressing plate and can rotate freely and slide freely along the guide grooves of the first pressing plate and the second pressing plate;

[0014] The two ends of the first spring are respectively fixedly connected to one end of the first rotating shaft and the second rotating shaft, and the two ends of the second spring are respectively fixedly connected to the other end of the first rotating shaft and the second rotating shaft. The first spring and the second spring are both in a stretched state, so that the first driving foot and the second driving foot are both against the side wall of the rotor;

[0015] The first actuator and the second actuator are used to receive external instructions to extend or shorten, so as to drive the rotor to rotate.

[0016] As an optimization solution of the friction actuator based on the conjugate curve mechanism of the present invention, the angle between the first actuator and the second actuator is 90°.

[0017] The present invention also discloses a working method of the friction actuator based on the conjugate curve mechanism, comprising the following steps:

[0018] Let the center of the first rotating shaft be the origin. Place your left hand at the origin with your thumb, index finger, and middle finger at right angles to each other. The direction of the thumb pointing from the second pressure plate toward the first pressure plate along the axis of the first rotating shaft is the positive direction of the Z axis, the direction of the index finger pointing is the positive direction of the Y axis, and the direction of the middle finger pointing is the positive direction of the X axis. In the XY plane, clockwise rotation of the rotor along the Z axis is positive rotation, and counterclockwise rotation of the rotor along the Z axis is negative rotation.

[0019] In the initial state, the first actuator and the second actuator maintain their initial lengths. Under the tension of the first spring and the second spring, the first driving foot and the second driving foot are in contact with the rotor, and the system is in a static equilibrium state.

[0020] If the rotor needs to rotate in the forward direction, drive it according to the following cycle:

[0021] Step A.1) driving the second actuator to gradually extend so that the second driving foot pushes the rotor to rotate in the positive direction by an angle θ1. Under the action of the reaction force of the rotor, the rotating bracket moves in the negative direction of the Y axis by Δh1.

[0022] Step A.2) driving the second actuator to shorten to its initial length so that the second driving foot is separated from the rotor, and the rotor maintains a constant forward rotation angle θ1;

[0023] In step A.3), under the action of the spring tension, the rotating bracket generates a positive rotation trend, and the first driving foot rotates forward with the rotating bracket and generates relative sliding movement with the rotor in a state of continuous contact. The second driving foot rotates forward with the rotating bracket while being separated from the rotor. During the rotation of the rotating bracket, the rotating bracket simultaneously moves in the positive direction of the Y axis. When the rotating bracket rotates through an angle of θ2, the second rotating shaft is in a balanced state and the second driving foot contacts the rotor again. At this time, the rotor rotates through an angle of θ1, and the rotating bracket rotates through an angle of θ2.

[0024] Step A.4), the first actuator and the second actuator return to their initial lengths and the first driving foot and the second driving foot contact the rotor, locking the rotor and restoring the system to a balanced state;

[0025] If the rotor needs to rotate in the opposite direction, drive it according to the following cycle:

[0026] Step B.1) driving the first actuator to gradually extend, causing the first driving foot to push the rotor to rotate in the opposite direction by an angle θ3. Under the action of the reaction force of the rotor, the rotating bracket moves Δh1 along the negative direction of the Y axis;

[0027] Step B.2), driving the first actuator to shorten to its initial length, so that the first driving foot is separated from the rotor, and the rotor maintains a constant forward rotation angle θ3;

[0028] In step B.3), under the action of the spring tension, the rotating bracket tends to rotate in the opposite direction, and the second driving foot rotates in the opposite direction with the rotating bracket, and generates relative sliding movement with the rotor while in continuous contact. The first driving foot rotates in the opposite direction with the rotating bracket while being separated from the rotor. During the rotation of the rotating bracket, it also moves in the positive direction of the Y axis. When the rotating bracket rotates through an angle of θ4, the second rotating shaft is in a balanced state and the first driving foot contacts the rotor again. At this time, the rotor rotates through an angle of θ3, and the rotating bracket rotates through an angle of θ4.

[0029] In step B.4, the first actuator and the second actuator return to their initial lengths and the first driving foot and the second driving foot contact the rotor, locking the rotor and restoring the system to a balanced state.

[0030] Compared with the prior art, the present invention adopts the above technical solution and has the following technical effects:

[0031] 1. The present invention eliminates the need for multiple clamping mechanisms and auxiliary mechanisms. Two actuators are used to achieve the continuous forward and reverse rotation required by the motor. The control circuit and control method are simple, assembly is simple, and processing and manufacturing costs are low.

[0032] 2. Strong adaptability. When friction and wear occur in the structure, the system can compensate itself through elastic elements, thus ensuring the normal operation of the system.

[0033] 3. The structure is simple. The current structure can be composed of two sets of drive mechanisms that can reproduce the same motion law of the follower. The forward and reverse rotation of the actuator can be considered to be coordinated and driven by the two drive mechanisms respectively, and the two sets of mechanisms do not affect each other when they are working. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a structural schematic diagram of the present invention;

[0035] Figure 2 is a top view of the present invention;

[0036] Figure 3 It is a right side view of the present invention;

[0037] Figure 4 It is a working principle diagram of the present invention when rotating in the forward direction.

[0038] In the figure, 1-first pressure plate, 2-second pressure plate, 3-first rotating shaft, 4-second rotating shaft, 5-first spring, 6-second spring, 7-rotating bracket, 8-first actuator, 9-second actuator, 10-first driving foot, 11-second driving foot, 12-rotor. DETAILED DESCRIPTION

[0039] The technical solution of the present invention is further described in detail below with reference to the accompanying drawings:

[0040] The present invention can be implemented in many different forms and should not be considered to be limited to the embodiments described herein. On the contrary, these embodiments are provided to make this disclosure thorough and complete and will fully convey the scope of the invention to those skilled in the art. In the accompanying drawings, components are enlarged for clarity.

[0041] It should be understood that although the terms first, second, third, etc. may be used herein to describe various elements, components, and / or parts, these elements, components, and / or parts are not limited by these terms. These terms are merely used to distinguish elements, components, and / or parts from each other. Therefore, the first element, component, and / or part discussed below can become the second element, component, or part without departing from the teachings of the present invention.

[0042] like Figure 1 、 Figure 2、 Figure 3 As shown, the present invention discloses a friction actuator based on a conjugate curve mechanism, comprising a rotor, a first pressure plate, a second pressure plate, a rotating bracket, a first actuator, a second actuator, a first driving foot, a second driving foot, a first bearing, a second bearing, a first rotating shaft, a second rotating shaft, a first spring, and a second spring;

[0043] The rotor is strip-shaped and includes an upper end surface, a lower end surface and side walls, and the curves of the side wall contours on both sides of the rotor are symmetrical conjugate curves. A first bearing mounting hole is provided through the center of the upper end surface of the rotor;

[0044] The first pressing plate and the second pressing plate have the same structure, with one end of each plate provided with a guide groove along its length direction and the other end provided with a fixing hole; the first pressing plate and the second pressing plate are symmetrical about the straight line where the guide groove is located;

[0045] The rotating bracket is columnar and has a second bearing mounting hole extending through it along its axis.

[0046] The first actuator and the second actuator are both cylindrical piezoelectric stacks, symmetrically arranged, with one end of each being fixedly connected to the side wall of the rotating bracket and perpendicular to the axis of the rotating bracket;

[0047] The first driving foot and the second driving foot are respectively arranged at one end of the first actuator and the second actuator away from the rotating bracket;

[0048] The first bearing is disposed in the first bearing mounting hole, with its outer ring fixedly connected to the rotor and its inner ring fixedly connected to the first rotating shaft, and both ends of the first rotating shaft fixedly connected to the fixing holes on the first pressing plate and the second pressing plate, respectively, so that the rotor is located between the first pressing plate and the second pressing plate and can rotate freely;

[0049] The second rotating shaft is provided with a first annular groove and a second annular groove respectively matching the guide grooves of the first pressing plate and the second pressing plate;

[0050] The second bearing is arranged in the second bearing mounting hole, the outer ring of the second bearing is fixedly connected to the rotating bracket, and the inner ring is fixedly connected to the second rotating shaft, and the first annular groove and the second annular groove on the second rotating shaft are respectively matched with the first pressing plate and the second pressing plate guide groove, so that the rotating bracket is located between the first pressing plate and the second pressing plate and can rotate freely and slide freely along the guide grooves of the first pressing plate and the second pressing plate;

[0051] The two ends of the first spring are respectively fixedly connected to one end of the first rotating shaft and the second rotating shaft, and the two ends of the second spring are respectively fixedly connected to the other end of the first rotating shaft and the second rotating shaft. The first spring and the second spring are both in a stretched state, so that the first driving foot and the second driving foot are both against the side wall of the rotor;

[0052] The first actuator and the second actuator are used to receive external instructions to extend or shorten, so as to drive the rotor to rotate.

[0053] The angle between the first actuator and the second actuator is preferably 90°.

[0054] like Figure 4 As shown, the present invention also discloses a working method of the friction actuator based on the conjugate curve mechanism, comprising the following steps:

[0055] Let the center of the first rotating shaft be the origin. Place your left hand at the origin with your thumb, index finger, and middle finger at right angles to each other. The direction of the thumb pointing from the second pressure plate toward the first pressure plate along the axis of the first rotating shaft is the positive direction of the Z axis, the direction of the index finger pointing is the positive direction of the Y axis, and the direction of the middle finger pointing is the positive direction of the X axis. In the XY plane, clockwise rotation of the rotor along the Z axis is positive rotation, and counterclockwise rotation of the rotor along the Z axis is negative rotation.

[0056] In the initial state, the first actuator and the second actuator maintain their initial lengths. Under the tension of the first spring and the second spring, the first driving foot and the second driving foot are in contact with the rotor, and the system is in a static equilibrium state.

[0057] If the rotor needs to rotate in the forward direction, drive it according to the following cycle:

[0058] Step A.1) driving the second actuator to gradually extend so that the second driving foot pushes the rotor to rotate in the positive direction by an angle θ1. Under the action of the reaction force of the rotor, the rotating bracket moves in the negative direction of the Y axis by Δh1.

[0059] Step A.2) driving the second actuator to shorten to its initial length so that the second driving foot is separated from the rotor, and the rotor maintains a constant forward rotation angle θ1;

[0060] In step A.3), under the action of the spring tension, the rotating bracket generates a positive rotation trend, and the first driving foot rotates forward with the rotating bracket and generates relative sliding movement with the rotor in a state of continuous contact. The second driving foot rotates forward with the rotating bracket while being separated from the rotor. During the rotation of the rotating bracket, the rotating bracket simultaneously moves in the positive direction of the Y axis. When the rotating bracket rotates through an angle of θ2, the second rotating shaft is in a balanced state and the second driving foot contacts the rotor again. At this time, the rotor rotates through an angle of θ1, and the rotating bracket rotates through an angle of θ2.

[0061] Step A.4), the first actuator and the second actuator return to their initial lengths and the first driving foot and the second driving foot contact the rotor, locking the rotor and restoring the system to a balanced state;

[0062] If the rotor needs to rotate in the opposite direction, drive it according to the following cycle:

[0063] Step B.1) driving the first actuator to gradually extend, causing the first driving foot to push the rotor to rotate in the opposite direction by an angle θ3. Under the action of the reaction force of the rotor, the rotating bracket moves Δh1 along the negative direction of the Y axis;

[0064] Step B.2), driving the first actuator to shorten to its initial length, so that the first driving foot is separated from the rotor, and the rotor maintains a constant forward rotation angle θ3;

[0065] In step B.3), under the action of the spring tension, the rotating bracket tends to rotate in the opposite direction, and the second driving foot rotates in the opposite direction with the rotating bracket, and generates relative sliding movement with the rotor while in continuous contact. The first driving foot rotates in the opposite direction with the rotating bracket while being separated from the rotor. During the rotation of the rotating bracket, it also moves in the positive direction of the Y axis. When the rotating bracket rotates through an angle of θ4, the second rotating shaft is in a balanced state and the first driving foot contacts the rotor again. At this time, the rotor rotates through an angle of θ3, and the rotating bracket rotates through an angle of θ4.

[0066] In step B.4, the first actuator and the second actuator return to their initial lengths and the first driving foot and the second driving foot contact the rotor, locking the rotor and restoring the system to a balanced state.

[0067] It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by those skilled in the art in the art to which this invention belongs. It should also be understood that terms such as those defined in common dictionaries should be understood to have meanings consistent with their meanings in the context of the prior art and, unless defined as such, will not be interpreted in an idealized or overly formal sense.

[0068] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A friction actuator based on a conjugate curve mechanism, characterized in that: The invention comprises a rotor, a first pressing plate, a second pressing plate, a rotating bracket, a first actuator, a second actuator, a first driving foot, a second driving foot, a first bearing, a second bearing, a first rotating shaft, a second rotating shaft, a first spring and a second spring; The rotor is strip-shaped and includes an upper end surface, a lower end surface and side walls, and the curves of the side wall contours on both sides of the rotor are symmetrical conjugate curves. A first bearing mounting hole is provided through the center of the upper end surface of the rotor; The first pressing plate and the second pressing plate have the same structure, with one end of each plate provided with a guide groove along its length direction and the other end provided with a fixing hole; the first pressing plate and the second pressing plate are symmetrical about the straight line where the guide groove is located; The rotating bracket is columnar and has a second bearing mounting hole extending through it along its axis; The first actuator and the second actuator are both cylindrical piezoelectric stacks, symmetrically arranged, with one end of each being fixedly connected to the side wall of the rotating bracket and perpendicular to the axis of the rotating bracket; The first driving foot and the second driving foot are respectively arranged at one end of the first actuator and the second actuator away from the rotating bracket; The first bearing is disposed in the first bearing mounting hole, with its outer ring fixedly connected to the rotor and its inner ring fixedly connected to the first rotating shaft, and both ends of the first rotating shaft fixedly connected to the fixing holes on the first pressing plate and the second pressing plate, respectively, so that the rotor is located between the first pressing plate and the second pressing plate and can rotate freely; The second rotating shaft is provided with a first annular groove and a second annular groove respectively matching the guide grooves of the first pressing plate and the second pressing plate; The second bearing is arranged in the second bearing mounting hole, the outer ring of the second bearing is fixedly connected to the rotating bracket, and the inner ring is fixedly connected to the second rotating shaft, and the first annular groove and the second annular groove on the second rotating shaft are respectively matched with the first pressing plate and the second pressing plate guide groove, so that the rotating bracket is located between the first pressing plate and the second pressing plate and can rotate freely and slide freely along the guide grooves of the first pressing plate and the second pressing plate; The two ends of the first spring are respectively fixedly connected to one end of the first rotating shaft and the second rotating shaft, and the two ends of the second spring are respectively fixedly connected to the other end of the first rotating shaft and the second rotating shaft. The first spring and the second spring are both in a stretched state, so that the first driving foot and the second driving foot are both against the side wall of the rotor; The first actuator and the second actuator are used to receive external instructions to extend or shorten, so as to drive the rotor to rotate.

2. The friction actuator based on the conjugate curve mechanism according to claim 1, characterized in that: The included angle between the first actuator and the second actuator is 90°.

3. The operating method of the friction actuator based on the conjugate curve mechanism according to claim 1, characterized in that: The following steps are involved: Let the center of the first rotating shaft be the origin. Place your left hand at the origin with your thumb, index finger, and middle finger at right angles to each other. The direction of the thumb pointing from the second pressure plate toward the first pressure plate along the axis of the first rotating shaft is the positive direction of the Z axis, the direction of the index finger pointing is the positive direction of the Y axis, and the direction of the middle finger pointing is the positive direction of the X axis. In the XY plane, clockwise rotation of the rotor along the Z axis is positive rotation, and counterclockwise rotation of the rotor along the Z axis is negative rotation. In the initial state, the first actuator and the second actuator maintain their initial lengths. Under the tension of the first spring and the second spring, the first driving foot and the second driving foot are in contact with the rotor, and the system is in a static equilibrium state. If the rotor needs to rotate in the forward direction, drive it according to the following cycle: Step A.1) driving the second actuator to gradually extend so that the second driving foot pushes the rotor to rotate in the positive direction by an angle θ1. Under the action of the reaction force of the rotor, the rotating bracket moves in the negative direction of the Y axis by Δh1. Step A.2) driving the second actuator to shorten to its initial length so that the second driving foot is separated from the rotor, and the rotor maintains a constant forward rotation angle θ1; In step A.3), under the action of the spring tension, the rotating bracket generates a positive rotation trend, and the first driving foot rotates forward along with the rotating bracket and generates relative sliding movement with the rotor in a continuous contact state; The second driving foot rotates in the positive direction along with the rotating bracket when it is separated from the rotor. During the rotation of the rotating bracket, it also moves in the positive direction of the Y axis. When the rotating bracket rotates through an angle θ2, the second rotating shaft is in a balanced state and the second driving foot contacts the rotor again. At this time, the rotor rotates through an angle θ1 and the rotating bracket rotates through an angle θ2. Step A.4), the first actuator and the second actuator return to their initial lengths and the first driving foot and the second driving foot contact the rotor, locking the rotor and restoring the system to a balanced state; If the rotor needs to rotate in the opposite direction, drive it according to the following cycle: Step B.1) driving the first actuator to gradually extend, causing the first driving foot to push the rotor to rotate in the opposite direction by an angle θ3. Under the action of the reaction force of the rotor, the rotating bracket moves Δh1 along the negative direction of the Y axis; Step B.2), driving the first actuator to shorten to its initial length, so that the first driving foot is separated from the rotor, and the rotor maintains a constant forward rotation angle θ3; In step B.3), under the action of the spring tension, the rotating bracket generates a reverse rotation tendency, and the second driving foot rotates in the reverse direction with the rotating bracket and generates relative sliding movement with the rotor in a continuous contact state; the first driving foot rotates in the reverse direction with the rotating bracket while being separated from the rotor; The rotating bracket simultaneously moves in the positive direction of the Y axis during the rotation process. When the rotating bracket rotates through an angle θ4, the second rotating shaft is in a balanced state and the first driving foot contacts the rotor again. At this time, the rotor rotates through an angle θ3 and the rotating bracket rotates through an angle θ4. In step B.4, the first actuator and the second actuator return to their initial lengths and the first driving foot and the second driving foot contact the rotor, locking the rotor and restoring the system to a balanced state.

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