Panasonic MINAS-BL GV Series Manual page 46

1. Example of motor selection for driving ball screw mechanism
Workpiece weight
Ball screw length
Ball screw diameter
Ball screw lead
Ball screw efficiency
Travel distance 0.3 [m]
Coupling inertia Jc = 10 × 10
2. Running pattern :
Acceleration time
Constant-velocity time
Deceleration time
Cycle time
Travel distance 0.3 [m]
3. Ball screw weight
4. Load inertia
5. Provisional motor selection
In case of GP series 50 W, gear ratio 1/5. Permissible load inertia moment = 3.42 × 10
6. Inertia moment compared
Permissible load inertia moment = 3.42 × 10
= 1.73 × 10 –4 [kg∙m 2 ] Cleared specification
7. Calculation of maximum velocity (Vmax)
1
× Acceleration time × Vmax + Constant-velocity time × Vmax +
2
1
× 0.7 × Vmax + 1.3 × Vmax +
2
2.0 × Vmax = 0.3
Vmax = 0.3 / 2.0 = 0.15 [m/s]
8. Calculation of motor velocity (N [r/min]) Ball screw lead per resolution: B
N = 0.15 / 0.02 = 7.5 [r/s]
= 7.5 × 60 = 450 [r/min] < 600 [r/min] (rated rotation speed of GP series 50 W, gear ratio 1/5)
9. Calculation of torque
Traveling torque T
Acceleration torque T
Deceleration torque T
W = 10 [kg]
A
B = 0.5 [m]
L
B = 0.02 [m]
D
B = 0.02 [m]
P
B = 0.9
–6 2 ] (Use manufacturer-specified catalog value, or calculation value.)
[kg∙m
Velocity
t = 0.7 [s]
a
t = 1.3 [s]
b
t = 0.7 [s]
d
t = 4 [s]
c
( )
2
B
D
B = × × × B
W L
2
= 1.24 [kg]
J = J + J + J = J +
L C B W C
= 0.00001 + (1.24 × 0.02
= 1.73 × 10 –4 [kg∙m 2 ]
–4
[kg∙m
1
× 0.7 × Vmax = 0.3
2
B
P
= ( W + F) =
f A
2 B 2 × 0.9
= 0.035 [N∙m]
J × 2 N [r/s]
L
= + Traveling torque =
a
Acceleration time [s]
= 0.012 + 0.035 = 0.047 [N∙m]
J × 2 N [r/s]
L
= – Traveling torque =
d
Deceleration time [s]
= 0.012 – 0.035 = – 0.023 [N∙m]
Travel distance
(slashed area)
Constant-
velocity time
Acceleration Deceleration
time time
Cycle time
( )
2
0.02
3
= 7.9 × 10 × × × 0.5
2
∙ B
1 W 2
A P
B × B 2 +
W D
2
4
8
2 ) / 8 + 10 × 0.02 2 / 4 2
2
] > Load inertia
1
× Deceleration time × Vmax = Travel distance
2
0.02
(0.1 × 9.8 × 10 + 0)
1.73 × 10
1.73 × 10
Stop
time
–4 [kg∙m 2 ]
= 0.02 [m]
P
–4 × 2 × 7.5
+ 0.035
0.7
–4 × 2 × 7.5
– 0.035
0.7
Time