SERVO SELECTION AND DATA SHEETS
5.1.1
Selecting a Servomotor
cont.
210
3) Machine Data Table
Fill out the machine data table below as an aid to selecting the drive system. When the
machine data table is complete, use the servomotor sizing software to select the motor
capacity.
1) Ball Screw Horizontal Axis
Load mass
W
kg (lb)
Thrust
F
kg (lb)
Coefficient of friction
µ
Table W
Overall efficiency
η
Table W
Motor
Gear ratio
R (= Nm/Nl)
Motor
Ball screw
Gear+coupling
GD
2
g
kg
¡
cm
2
(lb
¡
in
2
.)
Gear+coupling
GD
2
Ball screw
Ball screw pitch
P
mm (in.)
p g
GD
2
g
Ball screw diameter
D
mm (in.)
Ball screw length
L
mm (in.)
2) Ball Screw Vertical Axis
Load mass
W
1
kg (lb)
Counterweight
W
2
kg (lb)
Coefficient of friction
µ
Motor
Overall efficiency
η
Gear+coupling
Gear ratio
R (= Nm/Nl)
Gear+coupling
GD
2
g
Gear+coupling
GD
2
g
kg
¡
cm
2
(lb
¡
in
2
.)
Ball screw pitch
P
mm (in.)
Ball screw diameter
D
mm (in.)
B ll
Ball screw length
L
mm (in.)
Ball screw
3) Timing Belt
Load mass
W
kg (lb)
Pulley
Thrust
F
kg (lb)
Coefficient of friction
µ
Overall efficiency
η
Gear+coupling
Timing belt
Gear ratio
R (= Nm/Nl)
Gear+coupling
GD
2
g
Gear+coupling
GD
2
g
kg
¡
cm
2
(lb
¡
in
2
.)
Pulley
GD
2
d
kg
¡
cm
2
(lb
¡
in
2
.)
Motor
Pulley diameter
D
mm (in.)
4) Rack and Pinion
Load mass
W
kg (lb)
W
Thrust
F
kg (lb)
Rack
W
Coefficient of friction
µ
Rack
Overall efficiency
η
Pinion
Gear ratio
R (= Nm/Nl)
Gear+coupling
GD
2
Motor
Gear+coupling
GD
2
g
kg
¡
cm
2
(lb
¡
in
2
.)
p g
GD
2
g
Motor
Pinion diameter
D
mm (in.)
Pinion thickness
t
mm (in.)
5