Specification Symbol List; App. 5 Calculation Methods For Designing - Mitsubishi Electric HG-MR Instruction Manual

APPENDIX

App. 5 Calculation methods for designing

App. 5.1 Specification symbol list
The following symbols are required for selecting the proper servo.
T : Acceleration torque
a
T : Deceleration torque
d
T : Torque necessary for acceleration
Ma
T : Torque necessary for deceleration
Md
T : Load torque converted into equivalent value
LH
on servo motor shaft during stop
T : Load torque converted into equivalent value
L
on servo motor shaft
T : Unbalanced torque
U
T : Load friction torque
F
T : Brake static friction torque
B
T : Load torque on load shaft
L0
T : Continuous effective load torque converted
rms
into equivalent value on servo motor shaft
J : Load inertia moment converted into
L
equivalent value on servo motor shaft
J : Load inertia moment on load shaft
L0
J : Servo motor's rotor inertia moment
M
N: Servo motor speed
N : Servo motor speed during fast feed
0
N : Load shaft speed during fast feed
L0
V: Moving part speed
V : Moving part speed during fast feed
0
P : Ball screw lead
B
Z : Number of gear teeth on servo motor shaft
1
Z : Number of gear teeth on load gear
2
Z
2
n: Gear ratio n =
Z
1
Speed reduced when n > 1, Speed increased when n < 1
η: Drive system efficiency
[N•m] g: Gravitational acceleration (9.8 [m/s
[N•m] µ: Friction coefficient
[N•m] π: Pi constant (3.14)
[N•m] P : Number of feedback pulses in position control mode
f
[N•m] f: Input pulse frequency in position control mode
[N•m] f : Input pulse frequency during fast feed in position control
0
mode
[N•m] t : Acceleration time constant of pulse frequency
psa
command in position control mode
[N•m] t : Deceleration time constant of pulse frequency
psd
command in position control mode
[N•m]
[N•m] K : Position loop gain 1
p
[N•m] T : Position control time constant (Tp = 1/Kp)
p
[N•m] ∆l: Feed per feedback pulses in position control mode
Travel distance per pulse
[× 10 kg•m ] ∆l : Feed per command pulse in position control mode
-4 2
0
Travel distance per command pulse
[× 10 -4 kg•m 2 ] l: Feed
[× 10 -4 kg•m 2 ] P: Number of internal command pulses
[r/min] t : Internal settling time
s
[r/min] t : Positioning time
0
[r/min] t : Time at constant speed of servo motor in one cycle
c
[mm/min] tl: Stopping time in one cycle
[mm/min] ∆ : Positioning accuracy
ε
[mm] ε: Number of droop pulses
∆S: Travel distance per servo motor revolution
W: Mass
L : Maximum coasting distance
max
App. - 10
])
2
[pulse/rev]
[pulse/s]
[pulse/s]
[rad/s]
[mm/pulse]
[mm/pulse]
[pulse]
[pulse]
[mm/rev]
[s]
[s]
[s]
[mm]
[s]
[s]
[s]
[s]
[mm]
[kg]
[mm]