Mitsubishi Electronics MDS-R Benutzerhandbuch
Appendix 2. Selection
A2 - 15
Appendix 2-4 Motor shaft conversion load torque
The calculation method for a representative load torque is shown.
Type Mechanism
Calculation
expression
Linear
movement
movement
W
Z
1
Z
2
F
C
F
0
Servomotor
T
L
=
F in the above expression is obtained from the expression below
when the table is moved as shown on the left.
F = Fc +
(W . g + F
0
)
F.
∆S
2×10
3
V
N
) =
F
2×10
3
·(
Fc : Force applied on axial direction of moving section (N)
F
F
0
: Tightening force on inner surface of table guide
(N)
W : Total mass of moving section
(kg)
g : Gravitational acceleration = 9.8
(m/s
2
)
:
Friction
coefficient
T
L
: Load torque
(N.m)
F
: Force in axial direction of the machine
that moves linearly
(N)
: Drive system efficiency
V
: Speed of object that moves linearly
(mm/min)
N
: Motor speed
(r/min)
∆S
: Object movement amount per motor
rotation (mm)
Z1, Z2 : Deceleration ratio
Servomotor
T
LO
Z
1
Z
2
T
L
= · · T
LO
+ T
F
= · · T
LO
+ T
F
Rotary
movement
movement
W
2
W
1
1/n
Servomotor
Guide
Counter-
weight
weight
Load
When rising
T
L
= T
U
+ T
F
When lowering
T
L
= –T
U
·
2
+ T
F
T
U
=
· (
) =
T
F
=
Vertical
movement
movement
V
N
N
(W
1
W
2
) · g
2
10
3
(W
1
– W
2
) · g ·
∆S
2
10
3
· (W
1
+ W
2
) · g ·
∆S
2
10
3
1
T
L
: Load torque
(N.m)
T
LO
: Load torque on load shaft
(N.m)
T
F
: Motor shaft conversion load friction torque
(N.m)
: Drive system efficiency
Z
1
, Z
2
: Deceleration ratio
n
: Deceleration rate
T
L
: Load torque
(N.m)
T
U
: Unbalanced torque
(N.m)
T
F
: Friction torque on moving section
(N.m)
Z
1
Z
2
W
1
: Load mass
(kg)
W
2
: Counterweight mass
(kg)
: Drive system efficiency
g
: Gravitational acceleration = 9.8
(m/s
2
)
V
: Speed of object that moves linearly
(mm/min)
N
: Motor speed
(r/min)
∆S : Object movement amount per motor rotation (mm)
: Friction coefficient
1
1
n
n