10-04-2017, 09:34 PM
design review of shaft for strength and rigidity considerations ppt
Machine tool spindles and some line shafts are designed on the basis of torsional rigidity considerations. The total angle of twist in degrees is given by the Eq. (8.20). The permissible angle of twist or limiting value of twist for line shaft and machine tool (or spindle) applications are 3 and 0.25 per m length of shaft respectively.
Let us assume that the modulus of rigidity (G) of the shaft material is 79300 N/mm2, and the permissible angle of twist ( ) is 3 /m length of shaft. The distance between the bearings (l) is 600mm. This is the span length of shaft on which the maximum bending takes place and as a result, the maximum deflection also occurs.