Denso SMT7 - Design Example (High-Speed Transfer Equipment)

Chapter 2 Engineering Design of Servo Mechanism
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2.1.3 Design Example (High-Speed Transfer Equipment)
Fig. 2-2. High-speed transfer equipment
[Designing conditions]
1) Table design specification
Table weight : W
A
= 40 kg
Transferred object weight : W
L
= 20 kg (Max)
Max. stroke : S
max
= 700 mm
Fast feed speed : S
max
= 1000 mm/sec (60 m/min)
Positioning accuracy : ±0.10/700 mm (0.01 mm /pulse)
Repeat accuracy : ±0.010 mm
Required life : L
t
= 25000 hr (5 years)
Slide surface (rolling) :
 = 0.01 (Friction factor)
Drive motor : AC motor (Nmax = 3000 rpm)
2) Operation conditions
Fig. 2-3. Operation conditions
[Items to be decided]
1) Selection of screw shaft dia., lead and nut
2) Selection of accuracy and clearance
An explanation is given to these items as follows.
Sliding resistance
t = 3.5 sec/cycle
1 sec  2 times
Reciprocation
W
L
W
A