MABUCHI资料-永磁马达性能
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Foctor @ Flux Yoke
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Magnets areheldin a housing for theirf"lt housing will resultin magnetic force =p.ilil,ty.\ur,il",ring a thin-walt leaking through the housing wall.Thatis wheremagnet yokesare usedto prevent magnetic leakage thus maintaining thefullcapacity of the magnets.
orisinarwhire thecurrenr armost
Environmental temperature That same one
No'=
No x+
lo' + l o
ls' = ls Ts' = Ts
"+ "+
\f: voltage m be found tv) V : Originalvohage (v)
Let four performance.characteristics for neutral(No, 10,ls, Ts) and for leading in phase (N0,,lo', lsl Guide ) Motor performance ) Factors that cnange Motor performance
Foclor O Environmentol Temperofure
:T::jHil";:"t"t'*
Change per.t"C Magneticforce of magn", Wnding resislance __
affects themasnetic forces of masnets andthewindins resistance, soindicates chanses
N o ' = N ox 1
a
lo' = lo X 1
a
ls' = ls
Ts'=Tsx a
d; 1.08-1.12 i(thevaluethet'raries ,withyoke performane)
'The value of a varies with the degree of magnetic leakage and the wall thickness of flux yoke, and so assume a = 1.0E to 1.12,since the difference in motor performance between with and without flux yoke is about g to 12o/o.
Compare between neutral and leadanole Environmental temperature Thatsameone
r
l r ; 7
t \ U l
\ \^, -/
), respectively. Leadingin phase causes the no.loadspeed No'to slightlyincrease,as shown above, while all others stayalmostunchanged and N01 rises6 to 8% when leading12 to 15.. Note,however,that stall torque can be obtainedby using other than no-load and stall data. but in some cases Ts' may be smaller thanTs. A Point to Be Consideredfor Motors with Lead Angle Motorswith fon'rrard brush-shifl, when run in the reversedirection,will have, due to resultantlagging phase angle, adverseeffectsresultingin poor commutation,undesirableelectricalnoise, and shorter life. For this reason,the motorsmust be run in one directiononly.
supprv vortase
Supplement : Thermareffects on four performance-characters of motor r N0: No-load speed Themagnetic forceof riragnets becomes weaker and No risesin inverse proportion. o l0 : No-load current Thecurrent changes in inverse proportion to the magnetic forceof magnets, but is affected evenmorethan thatdueto the lossin bearing oil viscosity. In our approximation of 10, calculation is madewithout considering thermal changes. o ls: Stallcunent Because the cunentchanges in inverse proportion to thewindingresistance, as the temperature rises, ls falls. o Ts : Stalltorque Because the magneticforceof magnets becomes weakerwith decreasing current,as the temperature rises, Ts fallsgreaily.
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Techinrcal Guide ) Motor Performance ) Factors that change Motor performance
Foctpr O Phqse ^. i '\$t
tlrr.l _1Jwt,t.,t
refersto positionalrelationsbetween the centerlineof each polar magnet and the *.i.tPhase switching positionof ut$ --:, -. gmutatg( seomentsandt'rug!9s! Motors. assembled initially with neutralphase,runs under load laggingmomentarily phasedue to its In the electrical phenomenal armature reactionLegglngin phase,therefore, is not preferable, since it causes efficiency, electrrcal noise,and life to beco.Eeeven worse. To avoid these situations,improved motors are assembled with fonrrard brush-shifting that ofisets the armature reactionduring load operationto keep them on neutral electricallv Comparative Conditions Supply voltage Typeof powersupply Number of turnsperslot Diameter of magnet wire Typeof magnet Fluxyoke phase Thatsameone Constant-voltage powersupply Thatsameone Thatsameone Thatsameone None
Comparative Conditions
Thatsameone Constant-voltage powersuppty. Thatsameone Thatsameone Compare between wet and dry anisotropic magneE. Fluxyoke None Phase Thatsameone Environmental temperature Thatsameone
Techrnrcal Guide ) Motor performance ) Factors that change Motor performance
Foctor O Voltoge of Power Supply
lf only the voltageof power supply changes,the change in rlrotorperforrngsglin in vortage.
J"\ii,;U
direct proportion to that change
Asisquite apparent from thefisure berow, thespeed ,,""" .3:Y"T[)l:5,he
straignt on rtsline (Note,however'that theseproportional changesare not obtainable any more oeyoncla certain limitrange ) parative Conditions Supplyvoltage Type of power supply Number of turns per slot Diameterof magnet wire Type of magnet ' Flux yoke Phase Compare between 5V, 1OV,and .l5V That same one That same one That same one That same one None That same one
