Table 4 Optimization result.

Bearing span

1

Outer diameter of the shaft

0.085

Thickness of the shaft

0.014

Shear correction factor

0.5668

Distance

Left end bearing – Main generator

0.14

Main generator – Exciter

0.15

Exciter – PMG

0.14

PMG – Right end bearing

0.056

Length

Main generator

0.29

Exciter

0.062

PMG

0.030

Dummy mass

Main generator

1.000

Exciter

0.151

PMG

0.008

Dummy moment of inertia

Main generator

1.000

Exciter

0.092

PMG

0.001

Housing stiffness [N/mm]

Left end bearing

576,386

Right end bearing

76,868

Critical speed

1st natural mode (FW, 1X)

0.59

2nd natural mode (FW, 1X)

3.07

1st natural mode (FW, 2X)

0.29

2nd natural mode (FW, 2X)

1.27

Bending stress [MPa]

44.28