The rotary ultrasonic motor of bending vibration excitation and electric excitation mode thereof
Technical field
The present invention relates to rotary ultrasonic motor and the electric excitation mode thereof of the excitation of a kind of bending vibration, belong to ultrasound electric machine field.
Background technology
Ultrasound electric machine utilizes the inverse piezoelectric effect excitation ultrasound of piezoelectric ceramic to vibrate, and relies on the New Type of Actuator of frictional force drives.Rotary-type ultrasound electric machine belongs to the one of ultrasound electric machine.Compared with traditional electrical magneto, ultrasound electric machine has large torque mass ratio, fast response, precision positioning and without advantages such as electromagnetic interference, is with a wide range of applications in fields such as biologic medical, precision actuation, optics and Aero-Space.
The rotary ultrasonic motor patent retrieving existing expert's ripple finds, the mode realizing face expert's ripple mainly contains two kinds: adopt the excitation of patch type piezoelectric pottery and adopt sandwich oscillator mode to encourage.SMD motivation needs mills out plane in becket surface, is unfavorable for the formation of symmetrical profile expert ripple like this and higher to the requirement of barbola work; Sandwich vibrator type excitation extensively adopts longitudinal vibration to excite the in plane vibration of stator, and the normal direction mounting means of oscillator occupies more space, is unfavorable for the miniaturization of structure.There is the Novel rotary ultrasound electric machine adopting longitudinal vibration and the special-shaped mode acting in conjunction of bending vibration two kinds to excite face expert's ripple at present.Application number a kind of interior traveling wave rotary ultrasonic motor disclosed in 200910212678.5 adopts the oscillator of the vertical curved two kinds of vibration shapes that are coupled to excite the capable wave motion of the in-plane bending of annulus, the advantage of this electric machine structure is that structure is simple, processing technology is good, but the normal direction layout of oscillator is unfavorable for the microminiaturization of motor and the installation of stator and method of clamping have considerable influence to its mode of oscillation.The sandwich transducer that application number a kind of vertical curved combined type cylindrical shape rotary ultrasonic motor disclosed in 200910072818.3 adopts one to have a buckling composite mode equally excites face expert's wave motion of cylinder, be characterized in that sandwich oscillator is positioned at the tangential position of cylinder, two cantilever designs are adopted to be connected with cylinder, the advantage of this motor is compact conformation, but to the machining accuracy at cantilever position and matching requirements higher.In addition, the design of single coupling two kinds of special-shaped mode is comparatively complicated, requires to adopt dissimilar potsherd, and two kinds of mode in identical excitation situation, be difficult to reach amplitude consistent.
Summary of the invention
The present invention is directed to the deficiencies in the prior art, object is to provide a kind of and can realizes forward and reverse rotary motion and have ultrasound electric machine and the electric excitation mode of high-power output characteristic, motor body has stable performance, power output is large, compact conformation, more single to the requirement of potsherd, processing and the lower feature of matching requirements.
For realizing above technical purpose, the present invention will take following technical scheme:
A rotary ultrasonic motor for bending vibration excitation, the rotation axis comprising stator module, rotor assembly and axially place along stator module, and stator module and rotor assembly are coaxially arranged; Described stator module comprises round metal ring body and four piezoelectricity bending vibration; Described round metal ring body comprises top annulus, uniform four of the outer wall circumference of top annulus connects foot, these four connect foot and connect one to one with four piezoelectricity bending vibration, and this four piezoelectricity bending vibrations be that 90 ° of rotations are uniform around the central shaft of round metal ring body, while the length direction of each piezoelectricity bending vibration and the circumference of top annulus tangent.
The inner chamber of described top annulus is the biconical surface structure of opposing setting, and two conical surfaces of this biconical surface structure all equidistantly offer teeth groove, described rotor assembly comprises upper rotor part and the lower rotor part of split setting, upper rotor part, lower rotor part touch with two conical surfaces of biconical surface structure respectively, and the contact-making surface of upper rotor part, lower rotor part and biconical surface structure is all arranged in the conical surface; The Flexible Connector that described upper rotor part is arranged by pretension is installed on the rotating shaft, and lower rotor part is then fixed with rotation axis.
Described round metal ring body also comprises bottom clamping rings, and this bottom clamping rings is connected with top annulus by midfoot support wall.
Described piezoelectricity bending vibration attached bag draws together front end housing, bending vibration piezoelectric element, tail balancing weight block and threaded fastener; Bending vibration piezoelectric element is tightened up by threaded fastener and front end housing, and tail balancing weight block is pressed between bending vibration piezoelectric element and the nut of threaded fastener; Bending vibration piezoelectric element is two partition excitation structures, comprises bending vibration piezoelectric ceramic piece and electrode slice; Described bending vibration piezoelectric ceramic piece and electrode slice are even number sheet, and the setting alternate with electrode slice of bending vibration piezoelectric ceramic piece, the polarization border coordination of each bending vibration piezoelectric ceramic piece is arranged, and the positive and negative polarized area of two simultaneously adjacent bending vibration piezoelectric ceramic pieces is alternately arranged.
Another technical purpose of the present invention is to provide the electric excitation mode of the rotary ultrasonic motor of a kind of above-mentioned bending vibration excitation, respectively four piezoelectricity bending vibration are divided into two-phase: piezoelectricity bending vibration of wherein two alternate settings is a phase, flexural vibration mode in A profile is inspired under the effect of a road driving voltage signal, and piezoelectricity bending vibration of remaining two alternate settings is another phase, under the effect of another road driving voltage signal, be inspired Type B in-plane bending vibration mode; The two-way driving voltage signal applied is that the two-way of pi/2 phase difference is with frequency sinusoidal signal, in A profile, flexural vibration mode and Type B in-plane bending vibration mode have identical or close resonance frequency, the conical surface of the biconical surface structure of top annulus is impelled to produce row wave motion, cause the particle on this conical surface to have oval movement locus, drive rotor assembly rotates.
According to above technical scheme, following beneficial effect can be realized:
1, the present invention adopts bending vibration to excite the in-plane bending vibration of top annulus, and the length direction of piezoelectricity bending vibration and the excircle side of metal ring tangent, the quantity of piezoelectricity bending vibration is four simultaneously, it is uniform that central shaft around top annulus is 90 degree of rotations, this compact layout and structure, the Mode Shape excited is identical, and contributes to improving power output;
2, between the top annulus of round metal ring body and bottom retainer ring, there is one section of midfoot support thin-wall construction, be thisly designed with the installation and clamping that help stator, and less on the impact of its mode of oscillation;
3, the in-plane bending vibration excited by longitudinal vibration is changed into the in-plane bending vibration that bending vibration excites by the present invention, the transformation of the mode of oscillation of sandwich oscillator is mainly because the transformation of oscillator mounting arrangement determined: through FEM (finite element) calculation, the in-plane bending vibration of the more easy excitated stator metal ring of its bending vibration modes of the oscillator of tangential layout, and model frequency is lower, the amplitude that harmonic response calculates is higher, contributes to the output speed and the moment of torsion that improve motor.Compared with the design of coupling two kinds of mode, the single mode design of sandwich oscillator makes the structural design of stator comparatively flexible, convenient, and contributes to the in-plane bending vibration that many oscillators excite round metal ring body under same mode of oscillation.
4, the rotary ultrasonic motor of bending vibration of the present invention excitation is except the general characteristic with ultrasound electric machine, adopt the supporting construction of metal thin-wall, contribute to installation and the clamping of stator, and this design does not need to install bearing in addition, the function of automatic centering is played in the inner side cone structure of metal ring and the two-spool design of taper, and therefore motor can be operated in limit low temperature and vacuum environment etc. have particular/special requirement occasion to lubrication.
Accompanying drawing explanation
Fig. 1. the structural representation for bending vibration: wherein, Fig. 1-1 is cutaway view, and Fig. 1-2 is decomposition view.
Fig. 2 is the structural representation of stator: wherein, and Fig. 2-1 is front view, wherein comprises the broken section of midfoot support thin-walled, and Fig. 2-2 is stereogram.
Fig. 3. the rotary ultrasonic motor structural representation for the excitation of bending vibration: wherein, Fig. 3-1 is front view, wherein comprises the broken section of upper rotor part, lower rotor part and stator ring, and Fig. 3-2 is stereogram.
Fig. 4. the rotary ultrasonic motor operation principle schematic diagram for the excitation of bending vibration: wherein, Fig. 4-1 is three rank flexural vibration mode bending vibation mode picture in A profile, and Fig. 4-2 is three rank flexural vibration mode bending vibation mode picture in Type B face.
Number in the figure title: 1, round metal ring body; 2-1, the first bending vibration; 2-2, the second bending vibration; 3-1, the 3rd bending vibration; 3-2, the 4th bending vibration; 4, the first Double-conical-surface; 5, the second Double-conical-surface; 6, front end housing; 7, bending vibration piezoelectric ceramic piece; 8, tail balancing weight block; 9, fastening bolt; 10, electrode slice; 11, first connects foot; 12, second connects foot; 13, the 3rd connects foot; 14, the 4th connects foot; 15, top annulus; 16, midfoot support wall; 17, bottom retainer ring; 18, rotating shaft; 19, clamp nut; 20, spring leaf; 21, upper rotor part; 22, lower rotor part; 23, the first-order bending vibration mode of the first bending vibration; 24, the first-order bending vibration mode of the second bending vibration; Three rank flexural vibration modes in the A profile of 25, top annulus; 26,27,28 piezoelectricity pottery driving signal input is; 29, the first-order bending vibration mode of the 3rd bending vibration; 30, the first-order bending vibration mode of the 4th bending vibration; Three rank flexural vibration modes in the Type B face of 31, top annulus; 32,33,34 piezoelectricity pottery driving signal input is.
Embodiment
Accompanying drawing discloses the structural representation of preferred embodiment involved in the present invention without limitation; Technical scheme of the present invention is explained below with reference to accompanying drawing.
As shown in Figures 1 to 4, the rotary ultrasonic motor of bending vibration of the present invention excitation, the rotation axis comprising stator module, rotor assembly and axially place along stator module, and stator module and rotor assembly are coaxially arranged; Described stator module comprises round metal ring body and four piezoelectricity bending vibration; Described round metal ring body comprises top annulus, uniform four of the outer wall circumference of top annulus connects sufficient: namely the first connection foot 11, second connects foot the 12, the 3rd connection sufficient 13 and the 4th and connects foot 14, these four connect foot and connect one to one with four piezoelectricity bending vibration, and four described piezoelectricity bending vibration are: the sub-2-1 of the first bending vibration, the sub-2-2 of the second bending vibration, the sub-3-1 of the 3rd bending vibration, the sub-3-2 of the 4th bending vibration; And this four piezoelectricity bending vibrations be that 90 ° of rotations are uniform around the central shaft of round metal ring body, while the length direction of each piezoelectricity bending vibration and the circumference of top annulus tangent.
As shown in Fig. 2-1,2-2, the inner chamber of top of the present invention annulus is the biconical surface structure of opposing setting, and two conical surfaces of this biconical surface structure all equidistantly offer teeth groove, described rotor assembly comprises upper rotor part and the lower rotor part of split setting, upper rotor part, lower rotor part touch with two conical surfaces of biconical surface structure respectively, and the contact-making surface of upper rotor part, lower rotor part and biconical surface structure is all arranged in the conical surface, namely the main body of upper rotor part 21 of the present invention and lower rotor part 22 is circular cone structure; The Flexible Connector that described upper rotor part is arranged by pretension is installed on the rotating shaft, impel upper rotor part can move up and down along rotation axis, Flexible Connector of the present invention is spring leaf, this spring leaf 20 is arranged on the upper surface of upper rotor part 21, strain is there is under the effect of clamp nut 19, the contact that its component is in the axial direction rotor provides pretightning force, and the size of pretightning force is regulated by relative position axially between clamp nut 19 and rotation axis 18; Lower rotor part is then fixed with rotation axis; The lower surface of described top annulus, for the ease of the installation of stator module and clamping, is connected with bottom clamping rings by midfoot support wall by the present invention.
As shown in Fig. 1-1,1-2, piezoelectricity bending vibration attached bag of the present invention draws together front end housing, bending vibration piezoelectric element, tail balancing weight block and threaded fastener; Bending vibration piezoelectric element is tightened up by threaded fastener and front end housing, and tail balancing weight block is pressed between bending vibration piezoelectric element and the nut of threaded fastener; Bending vibration piezoelectric element is two partition excitation structures, comprises four bending vibration piezoelectric ceramic pieces and four plate electrode sheets; The setting alternate with electrode slice of described bending vibration piezoelectric ceramic piece, and the polarization border coordination of each bending vibration piezoelectric ceramic piece is arranged, the positive and negative polarized area of two simultaneously adjacent bending vibration piezoelectric ceramic pieces is alternately arranged.
Four piezoelectricity bending vibration are divided into two-phase by the present invention respectively: piezoelectricity bending vibration of wherein two alternate settings is a phase, flexural vibration mode in A profile is inspired under the effect of a road driving voltage signal, and piezoelectricity bending vibration of remaining two alternate settings is another phase, under the effect of another road driving voltage signal, be inspired Type B in-plane bending vibration mode; The two-way driving voltage signal applied is that the two-way of pi/2 phase difference is with frequency sinusoidal signal, in A profile, flexural vibration mode and Type B in-plane bending vibration mode have identical or close resonance frequency, the conical surface of the biconical surface structure of top annulus is impelled to produce row wave motion, cause the particle on this conical surface to have oval movement locus, drive rotor assembly rotates.
The rotary ultrasonic motor of described bending vibration excitation as shown in Figure 3, forms primarily of rotor 21 and 22 and stator.Its stator as shown in Figure 2.Upper rotor part 21 and lower rotor part 22 main body are circular cone structure, the conical surface is processed into stator contact face, lower rotor part 22 is fixed with rotation axis 18, upper rotor part 21 can on rotation axis 18 relative sliding, spring leaf 20 is arranged on the upper surface of upper rotor part 21, under the effect of clamp nut 19, strain occurs, the contact that its component is in the axial direction rotor provides pretightning force, and the size of pretightning force is regulated by relative position axially between clamp nut 19 and rotation axis 18.
Stator shown in Fig. 2 is made up of round metal ring body 1 and four bending vibrations sub-2-1,2-2,3-1,3-2 being connected with round metal ring body 1; The integrated processing of round metal ring body 1, comprise top annulus 15, midfoot support wall 16 and bottom retainer ring 17, wherein, top annulus drive surface is Double-conical-surface 4 and 5, and have teeth groove, uniform four of lateral surface connects foot 12,14,11,13, be connected with the end of four bending vibrations sub-2-1,2-2,3-1,3-2 respectively, four bending vibration are that 90 degree of rotations are uniform around the central shaft of round metal ring body, and the circumference of length direction and top annulus is tangent, composition four, upper and lower, left and right driver element; The upper surface of midfoot support wall 16 is connected with the lower surface of top annulus 15, and thin-walled position is diametrically at teeth groove and connect between foot; The upper surface of bottom retainer ring 17 is connected with the lower surface of midfoot support wall 16, and the lower surface of bottom retainer ring 17 is the installed surface of motor.
Operation principle of the present invention is below described in detail in detail:
The effective operation mode of stator of this Design of Ultrasonic Motor is in-plane bending vibration mode because four bending vibration are uniformly distributed, and adjacent two oscillators be 90 degree vertical, therefore the operation mode be applicable to is B
03, B
05and B
09three kinds, B represents flexural vibrations, is designated as the pitch circle number of vibration for first time, is designated as the pitch diameter number of vibration for second time.Hereafter control mode is with B
03operation mode is example.As shown in Fig. 4-1, driving signal input 26 ground connection, input 27 applies A+ phase signals
, input 28 applies A-phase signals
, the local buckling vibration B of sub-2-1 and 2-2 of illustrated bending vibration can be excited
2mode, has 2 nodes, in drive connect foot 12 with under is connected foot 14 motions, excite the B of top annulus 15
03three rank flexural vibration modes 25 in face, are defined as A pattern state; As shown in the Fig. 4-2, driving signal input 32 ground connection, input 33 applies B+ phase signals
, input 34 applies B-phase signals
, the local buckling vibration B of sub-3-1 and 3-2 of illustrated bending vibration can be excited
2mode, has 2 nodes, drives left connection foot 11 to be connected foot 13 motion with right, excites the B of top annulus 15
03in face, three rank flexural vibration modes 31, are defined as Type B mode; Due to structural symmetry, A pattern state and Type B mode are the same mode frequently of homotype in theory, but vibration shape phase difference of pi/4 bending wave wavelength in the circumferential, namely in space phase, differ pi/2.When four signals
,
,
with
when applying, the superposition of two mode 25,31 can make top annulus 15 produce face expert's wave motion simultaneously, and the tooth tip particle retinue ripple of inner side Double-conical-surface 4 and 5 does elliptic motion, rotates in x-y plane through rubbing action drive rotor 21 and 22.The positive and negative direction of rotor turns can be determined by the phase difference of A, B two-phase sinusoidal signal, i.e. pi/2 phase official post electric mover positive movement ,-pi/2 phase official post electric mover counter motion.