CN112366977A - Large-thrust large-stroke piezoelectric inchworm actuator and driving method thereof - Google Patents
Large-thrust large-stroke piezoelectric inchworm actuator and driving method thereof Download PDFInfo
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Abstract
The invention discloses a high-thrust large-stroke piezoelectric inchworm actuator and a driving method thereof. The piezoelectric actuating unit comprises a piezoelectric stack, two caps and two cylindrical tension springs; the motor actuating unit contains sleeve, cavity motor, flexible shaft coupling and clamping nut, prevents changeing the unit and contains end cover and ball spline section of thick bamboo. When the bidirectional large-thrust large-stroke actuator works, the two hollow motors are used for alternately rotating the two clamping nuts to the supporting surface for clamping, the expansion of the piezoelectric actuating unit is matched to push the lead screw to output small displacement, and the bidirectional large-thrust large-stroke actuator is realized in a repeated mode. The invention does not generate electromagnetism or receive electromagnetic interference, and eliminates the complex coupling phenomenon existing when the piezoelectric actuator unit is matched with the piezoelectric actuator unit for working, thereby being convenient for driving control.
Description
Technical Field
The invention relates to the field of piezoelectric actuators, in particular to a large-thrust large-stroke piezoelectric inchworm actuator and a driving method thereof.
Background
For decades, piezoelectric actuators have been widely used in aerospace, micro-robots, biomedicine, precision machining, optical engineering, and other fields due to their advantages of high precision, fast response, large output force, strong electromagnetic compatibility, power-off self-locking, flexible design, and the like. The piezoelectric actuator is a prime mover which adopts a certain principle or structure to accumulate or amplify micro strain generated by a piezoelectric material so as to realize large-stroke output. According to the vibration state utilized, there are divided into resonance type and non-resonance type. Among them, the resonance type has a high operating frequency, and is typically represented by an ultrasonic motor; the non-resonant type has a lower operating frequency, and generally includes two types: inchworm type and stick-slip type. In contrast, inchworm-type piezoelectric actuators generally have greater load bearing capabilities.
The piezoelectric inchworm actuator is named by simulating the movement of an insect inchworm in nature, accumulates the small step displacement of a piezoelectric stack by alternative clamping, finally realizes the actuation with large thrust and large stroke, and has great potential in the fields of wing folding of a morphing aircraft, aerospace self-adaptive structure adjustment and the like. However, most actuators of this type at home and abroad rely on direct contact friction to realize the clamping function, and the bearing capacity and long-term working reliability are limited. Therefore, Loverich et al, 2007 of Journal of internal material systems and structures, propose a novel inchworm piezoelectric actuator using a feed screw rod to perform quasi-static motion accumulation, which realizes reliable actuation under a pressure load with a large thrust and a large stroke, but the actuator cannot realize reverse actuation under a tension load due to the characteristic that a piezoelectric element resists pressure and does not resist tension; subsequently, in 2019, a patent named "a bidirectional high-thrust piezoelectric linear actuator" was disclosed by time-of-use et al (patent No. 208579541), which adds symmetrically arranged piezoelectric stacks on the basis of the structure proposed by Loverish for driving tensile and compressive loads, respectively, to realize bidirectional high-thrust actuation. However, due to the adoption of a symmetrically configured dual piezoelectric stack, the size envelope is increased and the structure is not compact enough. In addition, because one electromagnetic motor is adopted to drive the two clamping structures to be matched with the piezoelectric unit to carry out inchworm actuation, the complicated coupling exists between the clamping structures and the piezoelectric stack, which brings difficulty to matching control, and meanwhile, the electromagnetic motor is introduced, so that the actuator is provided with electromagnetism and is not anti-electromagnetic interference.
Disclosure of Invention
The invention aims to solve the problems of complex coupling matching control, longer size envelope, electromagnetism and electromagnetic interference resistance of an inchworm piezoelectric actuator in the prior art, and provides a large-thrust and large-stroke piezoelectric inchworm actuator and a driving method thereof.
The invention adopts the following technical scheme for solving the technical problems:
a large-thrust large-stroke piezoelectric inchworm actuator comprises a first motor actuating unit, a second motor actuating unit, a fixed cylinder, a first support ring, a second support ring, a first fixed ring, a second fixed ring, a piezoelectric actuating unit, a first anti-rotation unit, a second anti-rotation unit and a lead screw;
the fixed cylinder is a hollow cylinder with openings at two ends, the first support ring, the first fixed ring, the second fixed ring and the second support ring are coaxially arranged inside the fixed cylinder in sequence along the axial direction, the first support ring and the second support ring are symmetrically arranged in the same structure, and the first fixed ring and the second fixed ring are symmetrically arranged in the same structure;
the piezoelectric actuating unit comprises first to second caps, a piezoelectric stack and first to second cylindrical tension springs; the first cover cap and the second cover cap comprise limiting parts and extending parts; the limiting part and the extending part are hollow cylinders and are coaxially and fixedly connected, the diameter of the limiting part is smaller than that of the through hole of the first fixing ring, the diameter of the extending part is larger than that of the through hole of the first fixing ring, and a groove matched with the end part of the piezoelectric stack is formed in one end, far away from the extending part, of the limiting part;
the piezoelectric stack can stretch out and draw back under the excitation of periodic voltage signals, the interior of the piezoelectric stack is hollow, and two ends of the piezoelectric stack are respectively arranged in the grooves of the first cap limiting part and the second cap limiting part; the first cylindrical tension spring and the second cylindrical tension spring are symmetrically arranged on two sides of the piezoelectric stack, and two ends of the first cylindrical tension spring and the second cylindrical tension spring are fixedly connected with the limiting parts of the first cover cap and the second cover cap through drag hooks respectively so as to pre-tighten the piezoelectric stack and ensure effective displacement output;
the piezoelectric actuating unit can freely penetrate into the screw rod along the axis of the piezoelectric actuating unit and is arranged in the fixed cylinder between the first fixed ring and the second fixed ring, the extending part of the first cover cap extends out of the through hole of the first fixed ring, and the extending part of the second cover cap extends out of the through hole of the second fixed ring;
the first motor actuating unit and the second motor actuating unit respectively comprise a sleeve, a hollow motor, a flexible coupling and a clamping nut; the sleeve is a hollow cylinder with openings at two ends, and a hollow motor is arranged in the sleeve; the clamping nut comprises a flange plate and a threaded cylinder which are coaxially and fixedly connected, the diameter of the outer wall of the flange plate is larger than that of the through hole of the first supporting ring, and the diameter of the outer wall of the threaded cylinder is smaller than that of the through hole of the first supporting ring;
two ends of the fixed cylinder are respectively and coaxially fixedly connected with one end of the sleeve of the first motor actuating unit and one end of the sleeve of the second motor actuating unit; the flange plate of the clamping nut of the first motor actuating unit is positioned between the first fixing ring and the first limiting ring, and the threaded cylinder extends out of the through hole of the first limiting ring and is coaxially and fixedly connected with the rotor of the hollow motor of the first motor actuating unit through the flexible coupling of the first motor actuating unit; the flange plate of the clamping nut of the second motor actuating unit is positioned between the second fixing ring and the second limiting ring, and the threaded cylinder extends out of the through hole of the second limiting ring and is coaxially and fixedly connected with the rotor of the hollow motor of the second motor actuating unit through the flexible coupling of the second motor actuating unit;
the first anti-rotation unit and the second anti-rotation unit respectively comprise an end cover and a ball spline cylinder, wherein the center of the end cover is provided with a through hole for mounting the ball spline cylinder; the ball spline cylinder is fixed in the through hole of the end cover and is used for a lead screw to pass through so that the lead screw can only move axially and cannot rotate circumferentially;
the other ends of the first motor actuating unit sleeve and the second motor actuating unit sleeve are respectively and coaxially fixedly connected with the end covers of the first anti-rotation unit and the second anti-rotation unit;
spline through grooves are milled on the thread teeth on the two sides of the two ends of the screw rod along the axial direction so as to be capable of penetrating into the first ball spline cylinder and the second ball spline cylinder; the lead screw penetrates through the ball spline cylinder of the first anti-rotation unit, then sequentially penetrates through the hollow motor, the flexible coupling and the clamping nut of the first motor actuating unit, then sequentially penetrates through the first cap, the piezoelectric stack and the second cap of the piezoelectric actuating unit, and finally sequentially penetrates through the clamping nut, the flexible coupling, the hollow motor and the ball spline cylinder of the second anti-rotation unit; the lead screw is matched with the ball spline cylinders of the first anti-rotation unit and the second anti-rotation unit and is in threaded connection with the clamping nuts of the first motor actuating unit and the second motor actuating unit.
As a further optimization scheme of the high-thrust and large-stroke piezoelectric inchworm actuator, a hollow motor in the sleeve is a hollow ultrasonic motor or a hollow electromagnetic motor.
As a further optimization scheme of the high-thrust large-stroke piezoelectric inchworm actuator, a hollow motor in the sleeve is a hollow ultrasonic motor and comprises a base, a stator, a bearing, a check ring and a rotor;
the base, the stator, the retainer ring and the rotor are all symmetrical about the sleeve axis, and through holes for the lead screws to pass through are formed in the sleeve axis;
the stator is fixed on the base;
the flexible end of the rotor is abutted against the stator, and the outer wall of the rotor is connected with the inner wall of the retainer ring through a bearing;
the outer walls of the base and the retainer ring are fixedly connected with the inner wall of the sleeve.
As a further optimization scheme of the high-thrust large-stroke piezoelectric inchworm actuator, the lead screw adopts trapezoidal threads to ensure high-thrust driving.
As a further optimization scheme of the high-thrust and large-stroke piezoelectric inchworm actuator, the actuator further comprises a first grating encoder and a second grating encoder, sleeves of the first motor actuating unit and the second motor actuating unit are respectively provided with a first mounting hole and a second mounting hole, and the first grating encoder and the second grating encoder are respectively arranged in the first mounting hole and the second mounting hole and are respectively used for measuring the rotating speed of clamping nuts in the first motor actuating unit and the second motor actuating unit.
As a further optimized scheme of the high-thrust and large-stroke piezoelectric inchworm actuator, the fixed cylinder comprises two cylinders and a connecting ring, internal threads are arranged at two ends of the inner wall of the connecting ring, external threads matched with the internal threads of the connecting ring are arranged at one ends of the two cylinders, and two ends of the connecting ring are respectively connected with the two cylinder threads.
The invention also discloses a driving method of the large-thrust large-stroke piezoelectric inchworm actuator, which comprises the following steps:
the first motor actuating unit is positioned on the side A, the second motor actuating unit is positioned on the side B, and the load is positioned on the side A or the side B and applies force from the side A to the side B;
step 1), driving two hollow motors to drive clamping nuts of a first motor actuating unit and a second motor actuating unit to screw in from the side A to the side B along a screw rod until a flange of the clamping nut of the first motor actuating unit contacts with an extending part of a first cover cap of a piezoelectric actuating unit and tightly presses the piezoelectric actuating unit to a second fixing ring, and the flange of the clamping nut of the second motor actuating unit contacts with a second support ring and has a gap with the extending part of the second cover cap;
step 2), driving the piezoelectric actuating unit to extend to drive the screw rod and the clamping nuts of the first and second motor actuating units to move from B to A, and simultaneously, the clamping nut of the second motor actuating unit is driven by the hollow motor to continuously screw from A to B, and the clamping nut of the first motor actuating unit and the extending part of the first cover cap do not rotate due to the friction force in the process; when the piezoelectric actuating unit extends to the maximum stroke, the flange plate of the clamping nut of the second motor actuating unit contacts the second support ring;
step 3), the piezoelectric braking unit is driven to contract, a flange plate of a clamping nut of the second motor actuating unit abuts against a second support ring, the retraction of the loaded screw rod is prevented, meanwhile, the clamping nut of the first motor actuating unit is driven by the hollow motor to be screwed to the extending part of the first cover cap of the piezoelectric actuating unit along the screw rod to B due to the release of load force, the piezoelectric actuating unit is pressed to a second fixing ring of the fixing cylinder, and at the moment, the flange plate of the clamping nut of the second motor actuating unit contacts the second support ring and a gap exists between the flange plate and the extending part of the second cover cap;
and 4) repeating the steps 2) to 3), and accumulating the small displacement of the piezoelectric braking unit to realize the large-stroke actuation of the actuator.
Compared with the prior art, the invention adopting the technical scheme has the following technical effects:
1. only one piezoelectric actuating unit is adopted for driving, so that the structure of the whole machine is simplified, and the manufacturing cost is reduced;
2. the hollow ultrasonic motor is used as a driving element of the clamping nut, and the characteristics of high energy density, quick response, power failure self-locking and strong electromagnetic compatibility are fully utilized. Meanwhile, the whole actuator does not generate electromagnetism or is not interfered by the electromagnetism;
3. the two hollow motors are adopted to respectively drive the two clamping nuts, so that the complex coupling phenomenon existing when the clamping nuts are matched with the piezoelectric actuating unit for working is eliminated, and the driving control is facilitated.
Drawings
FIG. 1 is a schematic structural view of the present invention;
FIG. 2 is a schematic structural view of a hollow ultrasonic motor according to the present invention;
FIG. 3 is a schematic structural diagram of a piezoelectric actuator unit according to the present invention;
FIG. 4 is a schematic view of the structure of the fixed cylinder matching with the sleeves of the first and second motor actuating units;
FIG. 5 is a schematic view of the forward motion principle of the present invention under a pressure load;
FIG. 6 is a timing diagram illustrating the forward motion of the present invention under a pressure load;
FIG. 7 is a schematic diagram of the reverse motion principle of the present invention under a tensile load;
FIG. 8 is a timing diagram illustrating the reverse motion of the present invention under a tensile load.
In the figure, 1: ball spline barrel, 2: end cap, 3: hollow motor, 3-1: base, 3-2: bearing, 3-3: retainer ring, 3-4: rotor, 3-5: stator, 4: first support ring, 5: torsion spring coupling, 6: clamping nut, 7: piezoelectric actuation unit, 7-1: cap, 7-2: draw hook, 7-3: cylindrical tension spring, 7-4: piezoelectric stack, 8: screw rod, 9: grating encoder, 10: fixed cylinder, 10-1: sleeve, 10-2: cylinder, 10-3: and (7) connecting rings.
Detailed Description
The technical scheme of the invention is further explained in detail by combining the attached drawings:
the present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, components are exaggerated for clarity.
As shown in fig. 1, a large-thrust large-stroke piezoelectric inchworm actuator comprises a first motor actuating unit, a second motor actuating unit, a fixed cylinder, a first support ring, a second support ring, a first fixed ring, a second fixed ring, a piezoelectric actuating unit, a first anti-rotation unit, a second anti-rotation unit and a lead screw.
The fixed cylinder is a hollow cylinder with two open ends, the first support ring, the first fixed ring, the second fixed ring and the second support ring are coaxially arranged inside the fixed cylinder in sequence along the axial direction, the first support ring and the second support ring are symmetrically arranged in the same structure, and the first fixed ring and the second fixed ring are symmetrically arranged in the same structure.
As shown in fig. 3, the piezoelectric actuation unit includes first to second caps, a piezoelectric stack, and first to second cylindrical extension springs; the first cover cap and the second cover cap comprise limiting parts and extending parts; the limiting part and the extending part are hollow cylinders and are coaxially and fixedly connected, the diameter of the limiting part is smaller than that of the through hole of the first fixing ring, the diameter of the extending part is larger than that of the through hole of the first fixing ring, and a groove matched with the end part of the piezoelectric stack is formed in one end, far away from the extending part, of the limiting part;
the piezoelectric stack can stretch out and draw back under the excitation of periodic voltage signals, the interior of the piezoelectric stack is hollow, and two ends of the piezoelectric stack are respectively arranged in the grooves of the first cap limiting part and the second cap limiting part; the first cylindrical tension spring and the second cylindrical tension spring are symmetrically arranged on two sides of the piezoelectric stack, and two ends of the first cylindrical tension spring and the second cylindrical tension spring are fixedly connected with the limiting parts of the first cover cap and the second cover cap through drag hooks respectively so as to pre-tighten the piezoelectric stack and ensure effective displacement output;
the piezoelectric actuating unit can freely penetrate into the screw rod along the axis of the piezoelectric actuating unit and is arranged in the fixed cylinder between the first fixed ring and the second fixed ring, the extending part of the first cover cap extends out of the through hole of the first fixed ring, and the extending part of the second cover cap extends out of the through hole of the second fixed ring;
the first motor actuating unit and the second motor actuating unit respectively comprise a sleeve, a hollow motor, a flexible coupling and a clamping nut; the sleeve is a hollow cylinder with openings at two ends, and a hollow motor is arranged in the sleeve; the clamping nut comprises a flange plate and a threaded cylinder which are coaxially and fixedly connected, the diameter of the outer wall of the flange plate is larger than that of the through hole of the first supporting ring, and the diameter of the outer wall of the threaded cylinder is smaller than that of the through hole of the first supporting ring;
two ends of the fixed cylinder are respectively and coaxially fixedly connected with one end of the sleeve of the first motor actuating unit and one end of the sleeve of the second motor actuating unit; the flange plate of the clamping nut of the first motor actuating unit is positioned between the first fixing ring and the first limiting ring, and the threaded cylinder extends out of the through hole of the first limiting ring and is coaxially and fixedly connected with the rotor of the hollow motor of the first motor actuating unit through the flexible coupling of the first motor actuating unit; the flange plate of the clamping nut of the second motor actuating unit is positioned between the second fixing ring and the second limiting ring, and the threaded cylinder extends out of the through hole of the second limiting ring and is coaxially and fixedly connected with the rotor of the hollow motor of the second motor actuating unit through the flexible coupling of the second motor actuating unit;
the first anti-rotation unit and the second anti-rotation unit respectively comprise an end cover and a ball spline cylinder, wherein the center of the end cover is provided with a through hole for mounting the ball spline cylinder; the ball spline cylinder is fixed in the through hole of the end cover and is used for a lead screw to pass through so that the lead screw can only move axially and cannot rotate circumferentially;
the other ends of the first motor actuating unit sleeve and the second motor actuating unit sleeve are respectively and coaxially fixedly connected with the end covers of the first anti-rotation unit and the second anti-rotation unit;
spline through grooves are milled on the thread teeth on the two sides of the two ends of the screw rod along the axial direction; the lead screw penetrates through the ball spline cylinder of the first anti-rotation unit, then sequentially penetrates through the hollow motor, the flexible coupling and the clamping nut of the first motor actuating unit, then sequentially penetrates through the first cap, the piezoelectric stack and the second cap of the piezoelectric actuating unit, and finally sequentially penetrates through the clamping nut, the flexible coupling, the hollow motor and the ball spline cylinder of the second anti-rotation unit; the two ends of the screw rod are matched with the ball spline cylinders of the first anti-rotation unit and the second anti-rotation unit through the spline through grooves, and the rod body of the screw rod is in threaded connection with the clamping nuts of the first motor actuating unit and the second motor actuating unit through threads on the rod body.
As shown in fig. 2, the hollow motor in the sleeve is a hollow ultrasonic motor or a hollow electromagnetic motor, and when the hollow ultrasonic motor is adopted, the hollow ultrasonic motor comprises a base, a stator, a bearing, a retainer ring and a rotor; the base, the stator, the retainer ring and the rotor are all symmetrical about the sleeve axis, and through holes for the lead screws to pass through are formed in the sleeve axis; the stator is fixed on the base; the flexible end of the rotor is abutted against the stator, and the outer wall of the rotor is connected with the inner wall of the retainer ring through a bearing; the outer walls of the base and the retainer ring are fixedly connected with the inner wall of the sleeve.
The hollow ultrasonic motor firstly screws the retainer ring into a preset position of the sleeve, then sequentially installs the bearing, the rotor, the stator and the base, and applies proper pretightening force through rotating the base. When the piezoelectric ceramic stator works, the inverse piezoelectric effect of the piezoelectric ceramic plate is utilized to excite the two-phase same-frequency mode vibration of the stator, and then the microscopic vibration is converted into the macroscopic rotation of the rotor through friction.
The lead screw adopts trapezoidal threads to ensure high thrust driving.
The invention also comprises a first grating encoder and a second grating encoder, wherein sleeves of the first motor actuating unit and the second motor actuating unit are respectively provided with a first mounting hole and a second mounting hole, and the first grating encoder and the second grating encoder are respectively arranged in the first mounting hole and the second mounting hole and are respectively used for measuring the rotating speed of the clamping nut in the first motor actuating unit and the second motor actuating unit.
As shown in fig. 4, the fixed cylinder includes two cylinders and a connection ring, the connection ring has internal threads at both ends of the inner wall thereof, the two cylinders have external threads at one ends thereof matching the internal threads of the connection ring, and both ends of the connection ring are respectively connected to the two cylinder threads.
Internal threads are turned at the end part of one side of the cylinder and used for being screwed into the first support ring and the second support ring, wire outlet holes used for the piezoelectric actuating units are formed in the cylindrical surface, and external threads are turned at the two ends and used for being connected with the sleeve and the connecting ring respectively; an internal thread is turned at one end of the sleeve for installing the hollow motor, a threaded hole is formed in the end face of the sleeve for installing an end cover, and a round hole and a square hole are formed in the position of the hollow motor stator and the position of the clamping nut of the sleeve respectively. The round hole is used for leading out wires of the hollow motor stator, and meanwhile, the spanner is convenient for adjusting and fixing the parts by screws; the square hole is used for placing the grating encoder and is also used as a visual hole for observing the connection condition.
The invention also discloses a driving method of the large-thrust large-stroke piezoelectric inchworm actuator, which comprises the following steps:
the first motor actuating unit is positioned on the side A, the second motor actuating unit is positioned on the side B, and the load is positioned on the side A or the side B and applies force from the side A to the side B;
step 1), driving two hollow motors to drive clamping nuts of a first motor actuating unit and a second motor actuating unit to screw in from the side A to the side B along a screw rod until a flange of the clamping nut of the first motor actuating unit contacts with an extending part of a first cover cap of a piezoelectric actuating unit and tightly presses the piezoelectric actuating unit to a second fixing ring, and the flange of the clamping nut of the second motor actuating unit contacts with a second support ring and has a gap with the extending part of the second cover cap;
step 2), driving the piezoelectric actuating unit to extend to drive the screw rod and the clamping nuts of the first and second motor actuating units to move from B to A, and simultaneously, the clamping nut of the second motor actuating unit is driven by the hollow motor to continuously screw from A to B, and the clamping nut of the first motor actuating unit and the extending part of the first cover cap do not rotate due to the friction force in the process; when the piezoelectric actuating unit extends to the maximum stroke, the flange plate of the clamping nut of the second motor actuating unit contacts the second support ring;
step 3), the piezoelectric braking unit is driven to contract, a flange plate of a clamping nut of the second motor actuating unit abuts against a second support ring, the retraction of the loaded screw rod is prevented, meanwhile, the clamping nut of the first motor actuating unit is driven by the hollow motor to be screwed to the extending part of the first cover cap of the piezoelectric actuating unit along the screw rod to B due to the release of load force, the piezoelectric actuating unit is pressed to a second fixing ring of the fixing cylinder, and at the moment, the flange plate of the clamping nut of the second motor actuating unit contacts the second support ring and a gap exists between the flange plate and the extending part of the second cover cap;
and 4) repeating the steps 2) to 3), and accumulating the small displacement of the piezoelectric braking unit to realize the large-stroke actuation of the actuator.
The motion process of the large-thrust large-stroke piezoelectric inchworm actuator is similar to that of a common 'push-type' piezoelectric inchworm actuator, and displacement is accumulated through clamping, driving and clamping. As shown in fig. 5 and fig. 6 and 1, for convenience of description, in the drawings, the upper clamping nut and the lower clamping nut are respectively the clamping nuts of the first motor actuating unit and the second motor actuating unit, the upper hollow motor and the lower hollow motor are respectively the hollow motors of the first motor actuating unit and the second motor actuating unit, the upper fixing ring and the lower fixing ring are respectively the first fixing ring and the second fixing ring, and the upper supporting ring and the lower supporting ring are respectively the first supporting ring and the second supporting ring, and then the driving method of the forward motion under the pressure load is as follows:
1. when T =0 (initial state): the two hollow motors rotate the two clamping nuts, the upper clamping nut is screwed downwards along the screw rod and contacts with the piezoelectric actuating unit firstly, then the piezoelectric actuating unit is pressed on the lower fixing ring (clamping surface), and the lower clamping nut is pressed on the lower support ring;
2. applying a drive signal as shown in fig. 6 to the piezoelectric actuation unit and the two clamping nuts;
3. when 0< T < T/2: the piezoelectric actuating unit extends to drive the two clamping nuts and the loaded screw rod to move upwards together, and meanwhile, the lower clamping nut is driven by the lower hollow motor to rapidly screw into the lower support ring along the screw rod. In the process, the clamping nut cannot rotate due to the friction force of the contact surface;
4. when T = T/2, the piezoelectric actuating unit is extended to the maximum displacement, and the lower hollow motor rotates the lower clamping nut back to the lower support ring (clamping surface);
5. when T/2< T < T, the piezoelectric actuating unit contracts, the loaded lead screw is supported and clamped by the lower support ring, and the upper clamping nut is released from the load force and continues to screw along the lead screw under the drive of the upper hollow motor;
6. when T = T: the piezoelectric actuator unit retracts to its original length while the upper clamping nut is screwed back down onto the first cap. Thus, the screw rod moves forwards by a small displacement deltas, and the actuator completes a cycle of forward actuation.
7. The process 2-6 is repeated, so that the actuator can realize large-thrust and large-stroke actuation.
According to FIG. 7 and in combination with FIG. 8, the reverse motion of the large-thrust and large-stroke piezoelectric inchworm actuator under the tension load can be regarded as the mirror image motion of the forward motion of the large-thrust and large-stroke piezoelectric inchworm actuator under the pressure load. In the process, the piezoelectric actuating unit is supported by the upper supporting ring, the functions of the upper clamping nut and the lower clamping nut are interchanged, the two hollow motors reversely and alternately rotate the two clamping nuts to be matched with the extension of the piezoelectric actuating unit to push the reverse small displacement output of the screw rod, and the process is repeated to realize the large-stroke reverse motion of the actuator.
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 one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
The above-mentioned embodiments, objects, technical solutions and advantages of the present invention are further described in detail, it should be understood that the above-mentioned embodiments are only illustrative of the present invention and are not intended to limit the present invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (7)
1. A large-thrust large-stroke piezoelectric inchworm actuator is characterized by comprising a first motor actuating unit, a second motor actuating unit, a fixed cylinder, a first support ring, a second support ring, a first fixed ring, a second fixed ring, a piezoelectric actuating unit, a first anti-rotation unit, a second anti-rotation unit and a lead screw;
the fixed cylinder is a hollow cylinder with openings at two ends, the first support ring, the first fixed ring, the second fixed ring and the second support ring are coaxially arranged inside the fixed cylinder in sequence along the axial direction, the first support ring and the second support ring are symmetrically arranged in the same structure, and the first fixed ring and the second fixed ring are symmetrically arranged in the same structure;
the piezoelectric actuating unit comprises first to second caps, a piezoelectric stack and first to second cylindrical tension springs; the first cover cap and the second cover cap comprise limiting parts and extending parts; the limiting part and the extending part are hollow cylinders and are coaxially and fixedly connected, the diameter of the limiting part is smaller than that of the through hole of the first fixing ring, the diameter of the extending part is larger than that of the through hole of the first fixing ring, and a groove matched with the end part of the piezoelectric stack is formed in one end, far away from the extending part, of the limiting part;
the piezoelectric stack can stretch out and draw back under the excitation of periodic voltage signals, the interior of the piezoelectric stack is hollow, and two ends of the piezoelectric stack are respectively arranged in the grooves of the first cap limiting part and the second cap limiting part; the first cylindrical tension spring and the second cylindrical tension spring are symmetrically arranged on two sides of the piezoelectric stack, and two ends of the first cylindrical tension spring and the second cylindrical tension spring are fixedly connected with the limiting parts of the first cover cap and the second cover cap through drag hooks respectively so as to pre-tighten the piezoelectric stack and ensure effective displacement output;
the piezoelectric actuating unit can freely penetrate into the screw rod along the axis of the piezoelectric actuating unit and is arranged in the fixed cylinder between the first fixed ring and the second fixed ring, the extending part of the first cover cap extends out of the through hole of the first fixed ring, and the extending part of the second cover cap extends out of the through hole of the second fixed ring;
the first motor actuating unit and the second motor actuating unit respectively comprise a sleeve, a hollow motor, a flexible coupling and a clamping nut; the sleeve is a hollow cylinder with openings at two ends, and a hollow motor is arranged in the sleeve; the clamping nut comprises a flange plate and a threaded cylinder which are coaxially and fixedly connected, the diameter of the outer wall of the flange plate is larger than that of the through hole of the first supporting ring, and the diameter of the outer wall of the threaded cylinder is smaller than that of the through hole of the first supporting ring;
two ends of the fixed cylinder are respectively and coaxially fixedly connected with one end of the sleeve of the first motor actuating unit and one end of the sleeve of the second motor actuating unit; the flange plate of the clamping nut of the first motor actuating unit is positioned between the first fixing ring and the first limiting ring, and the threaded cylinder extends out of the through hole of the first limiting ring and is coaxially and fixedly connected with the rotor of the hollow motor of the first motor actuating unit through the flexible coupling of the first motor actuating unit; the flange plate of the clamping nut of the second motor actuating unit is positioned between the second fixing ring and the second limiting ring, and the threaded cylinder extends out of the through hole of the second limiting ring and is coaxially and fixedly connected with the rotor of the hollow motor of the second motor actuating unit through the flexible coupling of the second motor actuating unit;
the first anti-rotation unit and the second anti-rotation unit respectively comprise an end cover and a ball spline cylinder, wherein the center of the end cover is provided with a through hole for mounting the ball spline cylinder; the ball spline cylinder is fixed in the through hole of the end cover and is used for a lead screw to pass through so that the lead screw can only move axially and cannot rotate circumferentially;
the other ends of the first motor actuating unit sleeve and the second motor actuating unit sleeve are respectively and coaxially fixedly connected with the end covers of the first anti-rotation unit and the second anti-rotation unit;
spline through grooves are milled on the thread teeth on the two sides of the two ends of the screw rod along the axial direction so as to be capable of penetrating into the first ball spline cylinder and the second ball spline cylinder; the lead screw penetrates through the ball spline cylinder of the first anti-rotation unit, then sequentially penetrates through the hollow motor, the flexible coupling and the clamping nut of the first motor actuating unit, then sequentially penetrates through the first cap, the piezoelectric stack and the second cap of the piezoelectric actuating unit, and finally sequentially penetrates through the clamping nut, the flexible coupling, the hollow motor and the ball spline cylinder of the second anti-rotation unit; the lead screw is matched with the ball spline cylinders of the first anti-rotation unit and the second anti-rotation unit and is in threaded connection with the clamping nuts of the first motor actuating unit and the second motor actuating unit.
2. The high-thrust large-stroke piezoelectric inchworm actuator according to claim 1, wherein the hollow motor in the sleeve is a hollow ultrasonic motor or a hollow electromagnetic motor.
3. The high-thrust large-stroke piezoelectric inchworm actuator according to claim 2, wherein the hollow motor in the sleeve is a hollow ultrasonic motor and comprises a base, a stator, a bearing, a retainer ring and a rotor;
the base, the stator, the retainer ring and the rotor are all symmetrical about the sleeve axis, and through holes for the lead screws to pass through are formed in the sleeve axis;
the stator is fixed on the base;
the flexible end of the rotor is abutted against the stator, and the outer wall of the rotor is connected with the inner wall of the retainer ring through a bearing;
the outer walls of the base and the retainer ring are fixedly connected with the inner wall of the sleeve.
4. The high-thrust large-stroke piezoelectric inchworm actuator according to claim 1, wherein the lead screw is provided with trapezoidal threads so as to ensure high-thrust driving.
5. The high-thrust large-stroke piezoelectric inchworm actuator according to claim 1, further comprising a first grating encoder and a second grating encoder, wherein sleeves of the first motor actuating unit and the second motor actuating unit are respectively provided with a first mounting hole and a second mounting hole, and the first grating encoder and the second grating encoder are respectively arranged in the first mounting hole and the second mounting hole and are respectively used for measuring the rotating speed of clamping nuts in the first motor actuating unit and the second motor actuating unit.
6. The high-thrust large-stroke piezoelectric inchworm actuator according to claim 1, wherein the fixed cylinder comprises two cylinders and a connecting ring, the connecting ring is provided with internal threads at two ends of the inner wall of the connecting ring, the two cylinders are provided with external threads matched with the internal threads of the connecting ring at one end of the two cylinders, and two ends of the connecting ring are respectively connected with the two cylinder threads.
7. The driving method of the high-thrust large-stroke piezoelectric inchworm actuator according to claim 1, characterized by comprising the following steps:
the first motor actuating unit is positioned on the side A, the second motor actuating unit is positioned on the side B, and the load is positioned on the side A or the side B and applies force from the side A to the side B;
step 1), driving two hollow motors to drive clamping nuts of a first motor actuating unit and a second motor actuating unit to screw in from the side A to the side B along a screw rod until a flange of the clamping nut of the first motor actuating unit contacts with an extending part of a first cover cap of a piezoelectric actuating unit and tightly presses the piezoelectric actuating unit to a second fixing ring, and the flange of the clamping nut of the second motor actuating unit contacts with a second support ring and has a gap with the extending part of the second cover cap;
step 2), driving the piezoelectric actuating unit to extend to drive the screw rod and the clamping nuts of the first and second motor actuating units to move from B to A, and simultaneously, the clamping nut of the second motor actuating unit is driven by the hollow motor to continuously screw from A to B, and the clamping nut of the first motor actuating unit and the extending part of the first cover cap do not rotate due to the friction force in the process; when the piezoelectric actuating unit extends to the maximum stroke, the flange plate of the clamping nut of the second motor actuating unit contacts the second support ring;
step 3), the piezoelectric braking unit is driven to contract, a flange plate of a clamping nut of the second motor actuating unit abuts against a second support ring, the retraction of the loaded screw rod is prevented, meanwhile, the clamping nut of the first motor actuating unit is driven by the hollow motor to be screwed to the extending part of the first cover cap of the piezoelectric actuating unit along the screw rod to B due to the release of load force, the piezoelectric actuating unit is pressed to a second fixing ring of the fixing cylinder, and at the moment, the flange plate of the clamping nut of the second motor actuating unit contacts the second support ring and a gap exists between the flange plate and the diameter of the extending part of the second cover cap;
and 4) repeating the steps 2) to 3), and accumulating the small displacement of the piezoelectric braking unit to realize the large-stroke actuation of the actuator.
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| CN202011154549.8A CN112366977B (en) | 2020-10-26 | 2020-10-26 | Large-thrust large-stroke piezoelectric inchworm actuator and driving method thereof |
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20030226976A1 (en) * | 2002-02-14 | 2003-12-11 | Nikon Corporation | Stage-actuators that do not generate fluctuating magnetic fields, and stage devices comprising same |
| CN101521453A (en) * | 2009-04-02 | 2009-09-02 | 上海交通大学 | Heavy-loaded precision-displacement linear motor |
| CN103427704A (en) * | 2013-07-31 | 2013-12-04 | 南京航空航天大学 | Double-foot driving piezoelectric linear motor and electric excitation mode |
| CN108768206A (en) * | 2018-06-29 | 2018-11-06 | 南京航空航天大学 | A kind of two-way high thrust piezoelectric straight line actuator and its driving method |
| CN110198141A (en) * | 2019-06-27 | 2019-09-03 | 华侨大学 | Differential clamp formula looper type piezoelectric linear motor |
-
2020
- 2020-10-26 CN CN202011154549.8A patent/CN112366977B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20030226976A1 (en) * | 2002-02-14 | 2003-12-11 | Nikon Corporation | Stage-actuators that do not generate fluctuating magnetic fields, and stage devices comprising same |
| CN101521453A (en) * | 2009-04-02 | 2009-09-02 | 上海交通大学 | Heavy-loaded precision-displacement linear motor |
| CN103427704A (en) * | 2013-07-31 | 2013-12-04 | 南京航空航天大学 | Double-foot driving piezoelectric linear motor and electric excitation mode |
| CN108768206A (en) * | 2018-06-29 | 2018-11-06 | 南京航空航天大学 | A kind of two-way high thrust piezoelectric straight line actuator and its driving method |
| CN110198141A (en) * | 2019-06-27 | 2019-09-03 | 华侨大学 | Differential clamp formula looper type piezoelectric linear motor |
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