Item 40: Total Number of Rotor Slots, S_R
Use: S_R = S_A - X
Where X is an ODD integer that satisfactorily passes the following tests:
Test for Cogging: X ¹ 3p or its multiple.
Test for Cusp: X ¹ p, 2p, 5p.
Test for Noisy Operations: X ¹ 1, 2, p + 1, p + 2.

Item 41. Rotor Slot Pitch, l_r
Use: l_r = l × (S_A / S_R ).

Item 42. Current per Rotor Bar, Ir
Use: Ir = 0.85 Ic × (3 Z ) / S_R.

Item 43. Rotor Bar Current Density, D_R
Use: D_{R trial} = 1.3 D_final.
Where: D_final is Stator Current Density, item 25.
Use 2,500 A/sq.in. if D_{R trial} is less than this number.
Use: D_{R final} = Ir / CSb_final.
D_{R final} ranges from 2,500 to 4,500 A/sq.in.

Item 44. Dimensions of Rotor Bar, t_b × w_b
Use: CSb_trial = Ir / D_trial.
Use: tb_trial = a (CSb_trial).
Use: tb_final = Round-off to nearest three decimals.
Use: wb_trial = CSb_trial / tb_trial.
Use: wb_final = refer below:.

0.072	0.102	0.129	0.182	0.204	0.235	0.325	0.461	0.601	0.665	0.745
0.081	0.114	0.144	0.190	0.215	0.258	0.365	0.517	0.617	0.705	0.785
0.091	0.120	0.162	0.200	0.229	0.289	0.410	0.577	0.625	0.725	0.805

Choose the value that does NOT EXCEED the calculated wb_trial.
Use: CSb_final = tb_final × wb_final .

Item 45. Width of Rotor Slot, s_r
Use: s_r = wb_final

Item 45a. Width of Rotor Slot Opening, w_R
Use: w_R = 0.5 s_r = 0.5 wb_final

Item 46. Depth of Rotor Slot, d_r
Use: d_r = tb_final + t_h
Item 46a. Thickness of of Rotor Tooth, t_h
Use: t_h = 0.35 wb_final
Item 46b. Width of Rotor Tooth, t_r
Use: t_r = [ 2p ( D/2 - d_r ) / S_R ] - s_r
Where: S_R = No. of Rotor Slots, see Item 40.
s_r = rotor slot width, see Item 45.

Item 47. Maximum Flux Density in Rotor Teeth, B"t_R
Use: B"t_R = ( ½p × F × p ) / S_R × ln × t_r
Where: F = Flux per pole, see Item 21.
S_R = Rotor Slots, see Item 40.
ln = Net Armature Length, see Item 15.
Not to exceed 125,000 lines/sq.in., else increase rotor tooth width, tr.
B"t_R should be rounded to nearest 1,000.

Items 48 - 51

---

Home | EMD | Sites | ABdA | Help | E-mail