AC SERVO DRIVES - YASKAWA - #351

Use the AC servo drive capacity selection program SigmaJunmaSize+ to select servomotor capacity. The program can be downloaded for free from our web site (http://www.e-mechatronics.com/).

• Gear + coupling moment of inertia

: Jg = 0.40X10^-4 kg-m²

• Feeding times: n = 40 times/min

• Feeding distance: £ = 0.275 m

• Feeding time: tm = 1.2 s max.

Load speed: Vl = 15 m/min • Linear motion section mass: m = 250 kg Ball screw length: £_fi = 1.0 m Ball screw diameter: ofe = 0.02 m Ball screw lead: Pb = 0.01 m

Mechanical Specifications

Servomotor

Linear motion

Ball screw

Ball screw material density: p =7.87x103 kg/m³ • Friction coefficient: ^ = 0.2

Gear ratio: 1/2 (R = 2) ■ Mechanical efficiency: n = 0.9 (90%)

Gear

.60 60 . _c , ₎ ^t = 7T = 40 = ^{15 (s)}

where ta = td

ta = tm - ?" = 1.2 - ^{60 X}₁°²⁷⁵ = 1.2 - 1.1 = 0.1 (s)

V L 15

tc = 1.2 - 0.1 x 2 = 1.0 (s)

15 Speed (m/min)

Time (s)

\)l _ 15

1500 (min¹)

Load axis rotation speed m

Pb 0.01

• Motor shaft rotation speed Gear ratio 1/R = 1/2 (R=2)

Therefore, nu = nL- R = 1500 x 2 = 3000 (min^-1)

9.8u-m-PB 9.8 x 0.2 x 250 x 0.01 \

^Tl = 2n R-n ⁼-2n x 2 x 0.9-= ^{043 (N}'^m)

0.01

1.58 x 10⁴ (kg-m²)

• Linear motion section Jli = m

2n x 2

Ball screw

Coupling

Load moment of inertia at motor shaft

0.31 x 10-⁴ (kg-m²)

— P -&B-dB⁴- = 7.87 x 1Q3 x 1.0 x (0.Q2)⁴- —

₂2

32 - r² 32

Jg = 0.40 x 10⁴ (kg-m²)

Jl = Jli + Jb + Jg = (1.58 + 0.31 + 0.40) x 10⁴ = 2.29 x 10⁴ (kg-m²)

135(W)

2nnu -Tl 2n X 3000 X 0.43

60

60