Fuji Electric ALPHA7, User Manual

Page: 645 / 662

CHAPTER 16 APPENDIXES
18
Capacity Selection Calculation
16
Mechanism Features
Feed roll
The material on a plate (band) is sandwiched between rolls and fed.
Because the roll diameter is not obtained accurately, there is an
error in a long distance.
π
compensation is necessary.
Sudden acceleration causes slippage, resulting in shortage in the
feeding amount.
Table indexing
Because the moment of inertia of the table is large, a sufficiently
large reduction ratio is necessary.
The table rotation speed is low and a worm gear is usually used.
Spindle drive
Because winding of a wire material results in a larger moment of
inertia, a sufficiently large reduction ratio is necessary.
To achieve a constant surface speed, examination must be made,
including peripheral equipment.
Chain drive
Mainly used for the transfer line. Countermeasures against
elongation of the chain itself are necessary. Used mainly for
relatively large reduction ratios; the traveling speed of the
mechanical system is small.
 Approximate machine constants
Material density
Approximate friction coefficient
μ
Copper 8.96×10
3
Material Density kg/m
3
Brass 8.54×10
3
Stainless steel
Iron
Aluminum
Polyacetals 7.91×10
3
7.85×10
3
2.7×10
3
1.43×10
3
Rail and iron wheel
(Carrier and crane)
0.05
Mechanism Friction coefficient
Linear guide
Roller system
Roller table
Ball spline
0.05 ～ 0.2