Fuji Electric ALPHA7, User Manual

Page: 646 / 662

CHAPTER 16 APPENDIXES
Capacity Selection Calculation
19
16
Module
* Metric gear
Chain size
No. Pitch No. Pitch
15 4.762 80 25.4
25 6.35 100 31.75
35 9.525 120 38.1
40 12.7 140 44.45
50 15.875 160 50.8
60 19.05 180 57.15
16.5.2 Capacity Selection Calculation
Perform capacity selection calculation to obtain the servomotor capacity necessary for machine
specifications (configuration).
Items necessary for capacity selection calculation include the following.

Load inertia (moment of inertia of mechanical system)

Load torque (torque necessary to move the machine)

Acceleration/Deceleration time

Operation profile
In general, there is no way to measure the inertia of the mechanical system and load torque, calculate
approximate values according to the configuration of the machine.
Approximate mechanical efficiency
η
Trapezoidal screw thread 0.5 to 0.8
Mechanism Mechanical efficiency
Ball screw 0.9
Rack & Pinion
Gear reducer
Worm reducer
(starting)
Belt transmission
0.8
0.8 to 0.95
0.5 to 0.7
0.95
Worm reducer
(during operation)
0.6 to 0.8
0.9 Chain transmission
(Module)
＝
(Pitch circle diameter of gear)
(Number of teeth)
* Module
0.5 0.75 0.8 1 1.5 2 2.5 3 4 5 6 7