Reduction Gear Ratio; Pre-Load Torque - Fuji Electric Faldic-a RYS-R Series User Manual

In designing the mechanical equipment system, the following shoud be examined as required.
(a) Reduction gear ratio
Use near the rated speed of motor is recommended where possible.
(b) Pre-load torque
When applying a pre-load to screw, load torque increases.
(c) Holding torque at vertical drive.
At stop of a vertical-feed load machine, energized-motor has a holding torque unless an external-braking device is used.
(d) Mechanical efficiency
(e) Rough estimated mechanical-coefficients
(i) Friction coefficient μ
Application
Rail and iron wheel (crane traveling, traverse
motion, traveling carriage)
Linear way
Linear pole slide unit
Roller system
(2) Model type selection determination
(a) Flow chart for selecting a model type
(＊) : Trms : Actual torque
Tr : Rated torque
(ii) Mechanical efficiency η
Application
μ
0.05 Screw
Ball-screw
0.05 to 0.2 Rack and pinion
Spur gear reduction
Worm reduction gear
Belt drive
Chain drive
(iii) Densities of major materials ρ[kg/m
Steel
Stainless steel
Copper
Aluminum
Brass
Poly-acetal
(*)
11-2
η
0.5 to 0.8
0.9
0.8
0.8 to 0.95
At start 0.5 to 0.7
During operation 0.6 to 0.8
0.95
0.9
3
]
7850
7910
8960
2700
8540
1430
MHT260a (Engl.)