Question

Please solve this problem.

1. A rigid rotor is to be balanced by the addition of a fourth mass at a 178-mm radius. Three masses already exist and they are as follows: Mı = 1.81 kg, ri = 381 mm, 이 = 120°, My = 2.27 kg, r2-254 mm, 2-225°, lfg-: 0.907 kg, r3--305 mm, 3 :-330°. Determine the mass and angular position of the balancing mass using both graphical and analytical methods Draw a scale diagram of the rotor using solid lines for the known masses and dashed lines for the balancing mass. 2. Determine the amounts and angular positions of two masses which, if added at a 51-mm radius in planes L and R, will balance the rotor. 3. Determine the bearing reaction forces for the unbalanced rotor in the previous problem when the rotor is spinning at 1000 rpm. The shaft is mounted vertically so gravity is not in effect.

Answer 1

Moss Radis 1.8 254mm 2-22 178 mm 2 2a 3 man)m. Raclius 128 mm [쉬

4.glx0.381xsin 120+223 : O.25 4 xsin 22s* 드 90x 30ssin 336 n,, cos 05 r 292). ,6.osi 216 ) R. -TRe bace.cy fru .rs tten el mx O198O.sis4

.OSI21G -O.SI29 fon_T ΕΟ.09.qes う (teo

owing Agla 20° 3 30 Radius 38l mm 254mm ass 1.21 0 SI em 120 e tdre L m 2 2-27 3 0.9 0.305 m lose 0,6296 1 |0.381 m 120 225 830 1-8) 2966 O,

cmohuix su Cos Note. m the L and R plae