YASKAWA CPCR-MR08C Bulletin page 59

7. SELECTION GUIDE
7.1 DYNAMICS FORMULA FOR ELECTRIC FORCE
The drive system calculation is possible by knowing
the efficiency of the inlet (motor), the outlet (load),
and intermediate (reduction gear), etc.
Item Linear Motion Rotating Motion
T_
Reference Figure t ///////////,///
2z "NM'TL 2z "NM'TL
Basic Load Running Power Pc = 60 Pc = 60
o oa,cs [ /
Formula Load Accelerating Power p, = 2 z . NM × -- P, = • NM × --
ta _0- ta
9.8 × /_ • M. PB T,
Load Torque TL = 2 z .R. r/ TL -- R. r/
Load Inertia JL M [P2-_--_. R ] 2 1
= " JL = -R_ X J_
2 z XNM (JM+&) 2 z XNM (JM+&)
Starting Time ta = ta =
60 (Tp-TL) 60 (Tp-TL)
2 zXNM. (JM+&) 2 zXNM" (JM+&)
Braking Time td = td =
60 (Tp+ TL) 60 (Tp+ TL)
1 .D2 z D4 L "(_)
JK = _-X MK or J_= 32 " P "L" I- -i
Solid Cylinder Inertia MK:
Weight
of solid
cylinder (kg)
-:-._'O(m)
()
)]O(m)
p : Density (kg/m a)
Optimum Linear Motion Body JK: = M.D z _'
Reduction Equivalent Inertia _ M(kg) REDUCTION R ATIO1/Ro
Ratio & + N, + T,
94. ta
Optimum
Reduction Ratio Ro
= gM'Nt _] |_ T'
94" ta
._ a_
STARTING RUN BRAKING STANDSTILL
; : , -i
V, (NM) -_ _SPEED '/
Torque /r
TORQUE' _/ '_
RMS Torque RMS Value Trms =/_/ TP2 • ta+ TLz • tc+ TP_ " td Tp /(kg.m); \ ',
Value t TL 1___
'l
' i
TIME
i-__ _;. ....
TP, ta ', tc ', td : II (s)
i ' 1 CYCLE'(t) ' ='
I_ =',
Po : Running Power (W) /_ : Friction Coefficient TL: Load Torque (N.m)
P. : Accel Power (W) M:Weight of Linear Motion Part (kg) Tp:Average Motor Start Torque (N.m)
Nt:Driven Motor Speed (r/rain) Jr:Load Inertia (kg.m 2) Trms: Effective Average Torque (N.m)
NM : Motor Speed (r/min) JL : Load Inertia (kg.m 2) ta:Starting Time (s)
V_ : Load Speed (m/min=100cm/min) Ju: Motor Inertia (kg.m 2) tc: Running Time (s)
q :Speed Reducer Efficiency Tt : Load Torque td: Braking Time (s)
PB :Ball Screw Lead (m)
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