SANYO DENKI Technical Report No.20 Nov. 2005 34
Development of "SANMOTION F"
Stepping Motor 2-phase 42mm-sq. 0.9˚
New Products Introduction
Masaaki Oohashi Shigenori Miyairi
1. Introduction
Thesteppingmotorhasfeaturesthatarenotfoundinother
motors such as open loop control and high hit rate, and as a
result, it is widely used as a control motor in OA equipment,
medicalinstruments,andsemiconductormanufacturing
equipment.Each year,this typeof equipmentfaces growing
demandsforhigherprecision,morecompactsizes,andlower
costs,andsosteppingmotorsarealsobeingcalledonto
providehigher accuracy, lowervibrations, compactsize with
hightorque,andlowercosts.
Previously,applications thatrequired high precision used
the 5-phase stepping motor with its small step angle, but the
complexityofthedrivecircuits in the5-phasesteppingmotor
meansthatthesystemcostwashigh.Therefore,higher
accuracyhasbeencalledforin2-phasesteppingmotorswhich
havesimpledrivecircuitsandlowsystemcost.
Thisreportpresentsaproductoverviewandfeaturesofthe
2-phase42mmsq.0.9｡steppingmotor''SANMOTIONF'',
whichwasnewlydevelopedtorespondtotheseneeds.
Fig. 1 ''SANMOTION F''
4.5±0.15
Lead wire UL3385 AWG24
15±1
300 MIN.
1.5±0.76
33±0.5
15
+1
0
24±0.5
S
SR3 MIN.
(Effective length)
Cross section S-S
4-M3×0.5
□42±0.25
4-31±0.25
4.5±0.15
0
φ5
ｰ0.013
0
φ5
ｰ0.013
0
φ22
ｰ0.05
Fig. 2 External dimensions of the 2-phase 42mm Sq. 0.9｡stepping motor ''SANMOTION F''
SANYO DENKI Technical Report No.20 Nov. 200535
2. Product overview
2.1 Motor Dimensions
Theexternalviewofthe motor isshowninFig.1,and the
externaldimensionsoftheproductareshowninFig.2.
2.2 Specifications
Table1showstheproductspecifications.
The typical winding systems are the unipolar type (6 lead
wires),whichiscommonlyusedinJapan,andthebipolartype
(4leadwires), which iscommonlyusedin Europeandthe
UnitedStates.
Inthe unipolartype, thedrive circuits canbe madewith a
simpledesignforalowsystemcost.Thebipolartypefeaturesa
highusageratioofmotorwindingforprovidingalargetorque.
3. Features of the product
3.1 High Resolution
More teeth for the rotor and stator were used to enable a
highresolution.In thisproduct,thedie precisionoftherotor
andstatorwereimproved,andthenumberofteethwas
doubledfrombefore.Thisenabledtheobtainingof a high
resolutionatabasicstepangleof0.9｡comparedtotheregular
basicstepangleof1.8｡.
3.2 Low vibration and low noise
Fig.3showsthe motorstructure.Thebracketsused an
''innerdiameter spigotsystem''where theywere assembled
basedon the statorinner diameter.In this system, the rotor
and stator centers have high-level concentricity that enables
betterrotational balance forlower vibrations andlower noise.
Theinnerdiameterspigotsystemalsoenabledhigherrigidity
forthestatorsforlowervibrationsandlowernoise.
Fig.4showsavibrationcomparisonofthebasicstepangle
1.8｡steppingmotorandthenewly-developedbasicstepangle
0.9｡steppingmotor.Thesuperiorityofthe0.9｡steppingmotor
isevidentinnearlyallspeedranges.
3.3 High Torque
Ahightorquedesigninthesteppingmotorenablesittomove
large loads. Also, if the loads are identical, the smaller motor
canbeselected.Themorecompactdesigntakesuplessspace,
has lower cost, and also contributes significantly to resource
conservation.Theprimaryfactorthatcontributestothetorque
characteristicsof thestepping motoris the magneticcircuit
designof thestatorand rotor.Thisdevelopment usednew,
innovativemethodsandvarioustypesofsimulationstodevelop
the optimum magnetic circuit design. As a result, the torque
wasimprovedby1.5timesfromtheconventionalproduct.
Fig. 5 shows a comparison of the torque characteristics of
Endbracket
Rotor
Leadwireholder
Resincover
Leadwire
Leadwireoutlet
Bearing
Nameplate
Frontbracket
Stator
Shaft
Inner-diameter
spigotjoint
Bearing
Fig. 3 Motor Structure
Table 1 Specifications of 2-phase 42mm Square 0.9｡Stepping Motor SANMOTION F
Holding torque
Model
At 2-phase excitation
Rated current Winding resistance Rotor inductance
Rotor inertia Mass
Winding Single-ended Dual-ended
N･m MIN. A/phase Ω/phase mH/phase ×10-4 kg･m2kg
system spindle spindle
Unipolar SH1421-0441 -0411 0.201.2 2.7 3.2
Bipolar SH1421-5041 -5011 0.23 1 3.3 8 0.044 0.24
SH1421-5241 -5211 0.23 2 0.85 2.1
Unipolar SH1422-0441 -0411 0.29 1.2 3.1 5.3
Bipolar SH1422-5041 -5011 0.34 1 4 14 0.066 0.29
SH1422-5241 -5211 0.34 2 1.05 3.6
Unipolar SH1424-0441 -0411 0.39 1.2 3.5 5.3
Bipolar SH1424-5041 -5011 0.48 1 4.7 15 0.089 0.38
SH1424-5241 -5211 0.48 2 1.25 3.75
SANYO DENKI Technical Report No.20 Nov. 2005 36
Development of "SANMOTION F" Stepping Motor 2-phase 42mm-sq. 0.9˚
thisnew0.9｡steppingmotorandaconventional0.9｡stepping
motor.
3.4 Compact Size for Less Space
Manysteppingmotorshaveprotrusionswheretheleadwire
outletsextendfromthemotorsquarebody.Theconnectionis
containedwithinthisprotrusionbecauseitisdifficultto
providespace forthe connectionbetween the leadwire and
motorcoil wireinside themotor. However,a smallerdevice
sizeenablesamotordesignthattakesuplessspace,and this
protrusionoftheleadwireoutletcanbeahindranceto
developingacompactsize.Thisiswhyasteppingmotor
0.0
0.1
0.2
0.3
0.4
0.5
0.1 1 10 100
Pulserate（ｋｐｕｌｓｅ／ｓ ）
Torque （Ｎ・ｍ）
50 100 500 1000 2000
Numberofrotations（ｍｉｎ
-1
）
0
1
2
3
4
5
Torque （ｋｇｆ・ｃｍ）
Developedmotor:SH1422-0411(motorlength:39mm)
Conventionalmotor:103-594-0240
(motorlength:40.2mm)
Driver:Sanyoconstantcurrentcircuit
Supplyvoltage:24VDC
Excitationcurrent:1.2A/phase(Ave.)
Excitationsystem:2-phaseexcitationsystem
Loadinertia:JL=0.94×10
-4
kg×m
2
(includingrubbercoupling)
Fig. 5 Comparison of Torque Characteristics
Driver:Sanyoconstantcurrentcircuit
Supplyvoltage:24VDC
Excitationcurrent:1.2A/phase(Ave.)
Excitationsystem:2-phaseexcitationsystem
Tachogenerator:11TG(7V/1000min-1)
Conventionalmotor:103H5208-0410(1.8｡
step)
Developedmotor:SH1422-0411(0.9｡step)
0
0 20 40 60 80 100 120 140 160 180
0.5
1
1.5
2
2.5
3
TG output (Vrms)
Numberofrotations（ｍｉｎ
-1）
Fig. 4 Comparison of Speed Fluctuations in Basic Step Angle 0.9｡and 1.8｡
SANYO DENKI Technical Report No.20 Nov. 200537
Development of "SANMOTION F" Stepping Motor 2-phase 42mm-sq. 0.9˚
withoutanyprotrusionfortheleadwireoutletisdesirable.
Mostconventionalsteppingmotorswithoutprotrusionsfor
theleadwireoutletmaketheconnectionbetweentheleadwire
andmotor coil wire inside thestator slot.However, because
thestatorslotisaspaceforstoringthemotorcoil,the
connecting of the lead wire and motor coil wire in this space
naturallylimits thelength of the motor coiland reducesthe
motorcharacteristics(torqueandtemperaturerise).
Toresolvethisproblem,thenew''leadwireholdersystem''
wasdevisedandimplemented.Intheleadwireholdersystem,
theresin-madeleadwireholderandendbracketstructureare
designedsothat theconnectionbetween the leadwireand
motorcoilwire can bemadeinless space.Also,becausethis
systemdoes notuse astator slot,the protrusionof thelead
wireoutletcanbeeliminatedwithoutsacrificingmotor
characteristicsforenablingamorecompactsizethattakesup
lessspace.
4. Conclusion
The 2-phase 42mm square 0.9｡stepping motor
SANMOTIONFhasahighresolution,compactsize,andhigh
torqueandcancontributetohigherprecision,lowercosts,and
morecompact sizes forOA equipment,medical instruments,
andsemiconductormanufacturingequipment.
Wewillcontinue to worktodevelopmotors usingother
technologyforprovidingevenmoreimprovedperformancein
thefuture.
Masaaki Oohashi
JoinedSanyoDenkiin1982.
ServoSystemDivision,3rdDesignDept.
Workedonsteppingmotordevelopmentanddesign
Shigenori Miyairi
JoinedSanyoDenkiin1990.
ServoSystemDivision,3rdDesignDept.
Workedonsteppingmotordevelopmentanddesign