Background technology
Blade is wind-driven generator reception wind energy the critical component that converts thereof into kinetic energy, has determined reliability and useful life that generator is overall.Blade of wind-driven generator is usually operated at than under rugged environment, and self structure yardstick, weight and service load etc. are all very large, except because being subjected to irresistible natural calamity such as thunderbolt and earthquake etc. damages, the blade injury that spontaneous corrosion, wearing and tearing and fatigue stress etc. cause is also inevitable.Production practices show, in the wind-driven generator running, have an accident 1st/3rd, because of blade injury caused, therefore the health monitoring of fan blade is imperative.Along with the increase day by day of fan blade length and blower fan total number, relied on the method for manually making regular check on and being safeguarded can't meet Production requirement in the past.Therefore, people have proposed blade of wind-driven generator health status monitoring method or the technology of various ways, as Chinese patent 201210442074.1,200810057405.3,201110397347.0,201210149265.9 etc., for the Real-Time Monitoring of the states such as blade crackle, wearing and tearing and distortion provides effective means.But the powerup issue of existing automatic sensing and monitoring system not yet is well solved at present; therefore be difficult to, apply on a large scale; reason is: sensing and monitoring system need to be arranged on blade and with blade rotation; can't provide electric energy by wire, change battery and need often to shut down while adopting powered battery.Therefore, need a kind of microminiature Blast Furnace Top Gas Recovery Turbine Unit (TRT) of exploitation to meet the self-powered demand of monitoring system.
In recent years, for meeting the self-powered demand of all kinds of wireless sensing monitoring systems, people have proposed multiple microminiature oscillatory type piezoelectric generator, because of it, take the sheet type piezoelectric vibrator and be inverting element, therefore simple in structure, volume is little, integrated height, be particularly suited for wireless sensing monitoring system self-powered, the application that succeeded of some type oscillatory type piezoelectric generator.For meeting the power demands of rotary body health monitoring systems, utility model people had also once proposed multiple based on the rotary piezoelectric generator of magnetic couple excitation, as Chinese patent 201210319215.0,201210320165.8,201210318782.4,201210318930.2 etc.The characteristics of above-mentioned various rotary generators are must be by the effective excitation that realizes piezoelectric vibrator that relatively rotates between " fixtures " such as bearing pedestal or bearing caps and axle class " rotary body ", therefore can't be for the rotary body power generation needs of " without fixed support ", as the blade of rotation wind driven generator and automobile tire etc.
What in addition, existing rotary piezoelectric generator adopted is to wait width piezoelectric vibrator and its stiff end diameter to be less than free-ended diameter, drawback that magnet is installed to be: during piezoelectric vibrator flexural deformation, Root Stress is large, easily causes the piezoelectric vibrator damage; One timing of generator radial direction yardstick, a little less than little, the overall generating capacity of the area of piezoelectric vibrator; During high rotating speed, magnet centrifugal force can make that the axial vibration displacement of piezoelectric vibrator reduces, friction even, therefore generating efficiency is low; Most critical be, in work, piezoelectric vibrator bears pulse excitation, in a plurality of obvious vibration peaks, piezoelectric vibrator work, STRESS VARIATION is large, reliability is low therefore exist, effective speed belt is narrow.
Summary of the invention
It is a kind of based on the spacing wheeled piezoelectric beam generator of clamping that the utility model provides, and the problem that can't apply to solve the existing rotary piezoelectric generator extraneous fixed support of needs, to meet the power demands of blade of wind-driven generator monitoring system.
The technical solution adopted in the utility model is: left end cap and right end cap are arranged on respectively the barrel two ends of housing by screw, and described left and right end cap bottom inside is inlaid with respectively spacing ring one and bearing; Described housing is provided with two annular disks, by screw, is separately installed with spacing ring two on described two annular disks; Between the barrel of left end cap and housing and between the barrel of right end cap and housing, be crimped with respectively metal substrate, the piezoelectric chip of described metal substrate and its two side bonds forms piezoelectric vibrator jointly, the other end of described piezoelectric vibrator is clamped between the cusp of spacing ring one and spacing ring two, shown in the free end of piezoelectric vibrator by screw, moving magnet is installed; The rotating shaft two ends of cam-type excitation dish are arranged on left end cap and right end cap by bearing respectively, are inlaid with fixed magnet on the disk body of excitation dish; Identical and described each magnetic blow out centre of the radius of described moving magnet and fixed magnet equates apart from the distance of the centre of gyration of the rotating shaft of excitation dish; The pole orientation that is positioned at the fixed magnet that two circumferencial directions on excitation dish disk body are adjacent is opposite, and the opposite pole of moving magnet that is placed in piezoelectric vibrator end, the excitation dish disk body left and right sides is identical near the pole configuration direction of the moving magnet of installing and be placed in excitation dish disk body the same side.
For guaranteeing that the generator work hour indicator physique heart is in the spindle central below all the time, disk body gravity should meet:
η wherein
nFor being arranged on the moving magnet quantity and the greatest common divisor that is arranged on the fixed magnet quantity on disk body on disk body one side pressure electric tachometer indicator, Q<150 ° are the central angle of eccentric circular ring disk body, F
yFor between moving magnet and fixed magnet, producing maximum repulsive force in the circumferential direction of the circle, R is the distance of the center of moving magnet and fixed magnet to spindle central, R
GFor the distance of disk body barycenter to spindle central.
For guaranteeing in piezoelectric vibrator work because suffered stress is excessive, does not damage and make piezoelectric vibrator to bear attraction and the repulsive force alternately changed, should meet following relation between each parameter of generator:
Q
0=4arcsin (r/R), wherein, μ
0For permeability of vacuum, l is the axial distance between moving magnet and fixed magnet adjacent pole, and L is two axial distances between the moving magnet adjacent pole, m
1, m
2Be respectively the magnetic moment of moving magnet and fixed magnet, λ is the coefficient relevant with the structure of piezoelectric vibrator and material parameter, σ
*For the allowable tensile stress of piezoelectric chip material, Q
0For the angle between two adjacent fixed magnet centers on excitation dish disk body and excitation dish spindle central line.
The utility model has the advantages that novel structure, 1. utilize the characteristic of cam-type excitation dish centre-of gravity shift to make relative its spindle central of excitation dish keep static, thereby make to be arranged between fixed magnet on the excitation dish and the moving magnet with piezoelectric vibrator rotation, produce relative rotation, realize effective excitation the generating of piezoelectric vibrator, without extraneous fixed support; 2. this generator is parts independently, without changing the blade prototype structure, and is convenient to I&M in use procedure; 3. piezoelectric vibrator is because restricted by spacing ring, therefore high, the effective speed belt of the reliability of generator is wide, axial dimension is little; 4. the axial balanced configuration of piezoelectric vibrator, its vibration force is cancelled out each other, and can not pass to blade of wind-driven generator.
Embodiment
Left end cap 1 and right end cap 3 are arranged on respectively the two ends of the barrel 201 of housing 2 by screw, described left end cap 1 and right end cap 3 bottom inside are inlaid with respectively spacing ring 1 and bearing 8; Described housing 2 is provided with two annular disks 202, by screw, is separately installed with spacing ring 26 on described two annular disks 202; Between the barrel 202 of left end cap 1 and housing 2 and between the barrel 202 of right end cap 3 and housing 2, be crimped with respectively metal substrate 401, described metal substrate 401 and the common formation piezoelectric vibrator 4 of the piezoelectric chip 402 of its two side bonds, the other end of described piezoelectric vibrator 4 is clamped between the cusp of spacing ring 1 and spacing ring 26, shown in the free end of piezoelectric vibrator 4 by screw, moving magnet 7 is installed; Rotating shaft 901 two ends of cam-type excitation dish 9 are arranged on left end cap 1 and right end cap 3 by bearing 8 respectively; On the disk body 902 of excitation dish 9, be inlaid with fixed magnet 10; The radius of described moving magnet 7 and fixed magnet 10 is identical and described each magnetic blow out centre is equal apart from the distance of the centre of gyration of the rotating shaft 901 of excitation dish 9; The pole orientation that is positioned at the fixed magnet 10 that two circumferencial directions on the disk body 902 of excitation dish 9 are adjacent is opposite, be placed in the opposite pole of moving magnet 7 of disk body 902 arranged on left and right sides piezoelectric vibrator 4 ends near installing, and put identical with the pole configuration direction of the moving magnet 7 of disk body 902 the same sides.
For guaranteeing that the generator work hour indicator physique heart is in the spindle central below all the time, disk body gravity should meet:
η wherein
nFor being arranged on the moving magnet quantity and the greatest common divisor that is arranged on the fixed magnet quantity on disk body on disk body one side pressure electric tachometer indicator, Q<150 ° are the central angle of eccentric circular ring disk body, F
yFor between moving magnet and fixed magnet, producing maximum repulsive force in the circumferential direction of the circle, R is the distance of the center of moving magnet and fixed magnet to spindle central, R
GFor the distance of disk body barycenter to spindle central.
For guaranteeing in piezoelectric vibrator work because suffered stress is excessive, does not damage and make piezoelectric vibrator to bear attraction and the repulsive force alternately changed, should meet following relation between each parameter of generator:
Q
0=4arcsin (r/R), wherein, μ
0For permeability of vacuum, l is the axial distance between moving magnet and fixed magnet adjacent pole, and L is two axial distances between the moving magnet adjacent pole, m
1, m
2Be respectively the magnetic moment of moving magnet and fixed magnet, λ is the coefficient relevant with the structure of piezoelectric vibrator and material parameter, σ
*For the allowable tensile stress of piezoelectric chip material, Q
0For the angle between two adjacent fixed magnet centers on excitation dish disk body and excitation dish spindle central line.
In the course of work, right end cap 3 is arranged on blade of wind-driven generator 11 by screw, and rotates around wind driven generator principal shaft 12 with wind-driven generator blade 11; When moving magnet 7 is underlapped in a circumferential direction near fixed magnet 10 and described two magnet in a circumferential direction, between moving magnet 7 and fixed magnet 10, produce directed force F in the circumferential direction of the circle
yThereby, produce the driving torque M that fixed magnet 10 is rotated along rotating shaft 901
y, when moving magnet 7 and fixed magnet 10 driving moment maximum when circumferencial direction " tangent ", be M
y=RF
y, wherein R is the distance that rotating shaft 901 centers are arrived at moving magnet 7 and fixed magnet 10De center; Due to the barycenter of the disk body 902 of the wheeled excitation dish 9 of the utility model convexity, be positioned at the below of rotating shaft 901, when disk body 902 because being subjected to driving torque M
yEffect turns over certain angle Q
1The time, the gravity G of disk body 902 produces a reverse brake torque M
G=GR
GCosQ
1, R wherein
GFor the distance of disk body 902 barycenter to rotating shaft 901 centers.
For the barycenter of
guaranteeing disk body 902 in the generator course of work, be in all the time the below at rotating
shaft 901 centers, should make to work as
disk body 902 corners is Q
1Between=(180-Q)/2 o'clock each moving
magnets 7 and fixed
magnet 10, the driving torque sum is less than or equal to brake torque, namely
The gravity that obtains thus
disk body 902 should meet:
η wherein
nFor being arranged on the quantity n of the moving
magnet 7 on
disk body 902 1 side pressure
electric tachometer indicators 4
aWith the quantity n that is arranged on the fixed
magnet 10 on
disk body 902
bGreatest common divisor, Q<150 ° are the central angle of eccentric circular
ring disk body 902.
When disk body 902 does not rotate with right end cap 3, produce relative rotation between moving magnet 7 and fixed magnet 10; And then change the suffered axial repulsive force of moving magnet 7, make piezoelectric vibrator 4 produce reciprocal axial bending distortion and convert mechanical energy to electric energy.
In the above-mentioned course of work of generator, the suffered axial force of piezoelectric vibrator is the axial force between moving
magnet 7 and fixed magnet 10.The left
side moving magnet 7 in Fig. 1 of take is example, and its suffered total axial force is:
Wherein :+,-number mean respectively attraction and repulsive force,
For the active force between moving
magnet 7 and
fixed magnet 10,
Be the axial attraction between two moving
magnets 7, η
SFor the ratio of the overlapping area between moving
magnet 7 and single or
fixed magnet 10 that two circumferencial directions are adjacent with the magnet gross area, l is the axial distance between moving
magnet 7 and
fixed magnet 10 adjacent poles, and L is two axial distances between moving
magnet 7 adjacent poles, m
1, m
2Be respectively the magnetic moment of moving
magnet 7 and
fixed magnet 10, μ
0For permeability of vacuum.When moving
magnet 7 overlapped with fixed
magnet 10 center lines, Area Ratio was η
S=1, now the attraction between moving, fixed magnet is greater than repulsive force, therefore the suffered maximum force of
piezoelectric vibrator 4 is
For guaranteeing that
piezoelectric chip 402, at work not because bearing excessive tension stress damage, should make
Wherein λ is the coefficient relevant with the structure of
piezoelectric vibrator 4 and material parameter, σ
*Allowable tensile stress for the piezoelectric chip material.
For making between moving magnet 7 and fixed magnet 10 to produce attraction and the repulsive force alternately changed, in the utility model, should not overlap simultaneously with two adjacent fixed magnets 10 in moving magnet 7 rotary courses, be moving magnet 7 when with a fixed magnet, " cutting out " with another fixed magnet " incision ", Area Ratio now is η
S=0, the angle on the disk body 902 of excitation dish 9 between the line at rotating shaft 901 centers of two adjacent fixed magnet 10De centers and excitation dish 9 should be Q
0=4arcsin (r/R), wherein r, R are respectively radius and the corresponding radius of gyration of magnetic blow out centre of magnet.In this case, what piezoelectric vibrator 4 bore is harmonic excitation, therefore only can under its natural frequency, resonate; On the contrary, cantilever beam type piezoelectric vibrator generator for existing infinite place ring clamping, for avoiding moving, between fixed magnet, adsorb, can only adopt the method excitation of repulsion, its energisation mode is the periodic shock excitation, the cantilever beam type piezoelectric vibrator all formant can occur when the integral multiple of its natural frequency or integer/mono-times, during resonance, amplitude is excessive easily causes the piezoelectric vibrator damage but not resonance point may can't meet instructions for use because of amplitude and the brownout generated again.
It is fan-shaped in the utility model, adopting piezoelectric vibrator 4, and the width of stiff end is greater than free-ended width.According to mechanics of materials knowledge, the stress distribution that the stress distribution ratio on fan-shaped piezoelectric vibrator length direction waits the width cantilever beam piezoelectric vibrators evenly and the maximum stress less of stiff end, thereby improve intensity and the reliability of generator; Simultaneously, while adopting fan-shaped piezoelectric vibrator, the ξ when in the generator cross section, the effective area of piezoelectric vibrator waits the width cantilever beam piezoelectric vibrators for employing=(R
d/ r
x+ 1)/2 times, R wherein
dAnd r
xBe respectively the rear large radius of piezoelectric vibrator of assembling and minor radius, as R
d/ r
x=5 ξ=3.Therefore in the situation that the suffered mean stress of piezoelectric vibrator equate, the energy output of fan-shaped cantilever beam piezoelectric vibrators is the ξ that waits the width cantilever beam piezoelectric vibrators=(R
d/ r
x+ 1)/2 times; In addition, while adopting fan-shaped piezoelectric vibrator, the radius of gyration of its end magnet is little, therefore centrifugal force self and little on the impact of magnet axial motion can be realized the effective generating under high rotating speed.
In the utility model, the free end of piezoelectric vibrator 4 is clamped by the cusp of two spacing rings 1 and spacing ring 26, cusp around described spacing ring while being subjected to External Force Acting rotates, with the cantilever beam piezoelectric vibrators of infinite place ring, compare its bending rigidity and natural frequency is high, the free end axial deflection is little, therefore the voltage of two kinds of different operating mode piezoelectric vibrators-rotary speed property difference, i.e. Vg-n characteristic curve difference in Fig. 5.In Fig. 5, ZL and XL are respectively the voltage response of restraining position ring block piezoelectric vibrator in conventional cantilever beam piezoelectric vibrator and the utility model, as can be seen from the figure, a plurality of rotating speeds that make output voltage peak value occur are arranged in the ZL curve, and maximum and minimum voltage differ larger, when maximum voltage is too high, easily make piezoelectric vibrator be difficult to again meet the demand of powering in real time when too low because being out of shape excessive and cracked minimum voltage; Comparatively speaking, the maximum of XL curve and the difference of minimum voltage are less, and namely piezoelectric vibrator is less in the fluctuation of whole rotating speed territory internal stress during restraining position ring block, and piezoelectric vibrator is unlikely because being out of shape excessive the damage, therefore high, the effective speed belt of reliability is wide.In the 100-900r/min scope, the magnitude of voltage of XL curve all is greater than the required 5V supply power voltage of sensing and monitoring system, and the voltage of ZL curve after rotating speed is greater than 500r/min is all lower than 5V, so in the utility model, adopt the deflection of spacing ring restriction piezoelectric vibrator can effectively improve reliability and effective speed belt width of piezoelectric vibrator.
In the utility model, utilize the characteristic of cam-type excitation dish centre-of gravity shift to make relative its spindle central of excitation dish keep static, thereby make to be arranged between fixed magnet on the excitation dish and the moving magnet with piezoelectric vibrator rotation, produce relative rotation, realize effective excitation the generating of piezoelectric vibrator, without extraneous fixed support; This generator is parts independently, without changing the blade prototype structure, and is convenient to I&M in use procedure; Piezoelectric vibrator is because restricted by spacing ring, therefore high, the effective speed belt of the reliability of generator is wide, axial dimension is little.