28-02-2019, 07:08 AM
I cannot see the benefit of fitting a single row deep groove ball bearing and a double row self aligning bearing on the front of an Austin Seven crankshaft.
The self aligning capability is negated by the ball bearing although the drsa bearing rolls a little more easily than say a roller bearing.
The original ball and roller bearing combination gave a radial load capacity and axial capacity which with similar internal radial clearances the bearing loads would be shared reasonably well.
The axial movement due to radial clearance in the single row deep groove ball bearing would be somewhere about 3 to 4 times the radial clearance - around 2-3 thou mounted and the engine survived on this end float until the pair of angular contact ball bearings were introduced, probably giving about 0 to 1 thou end float with standard bearings nowadays.
The suggestion about the flanged outer ring rear roller bearing retaining oil could be correct but it would seem to be difficult to remove the plain inner ring from the crankshaft.
The self aligning capability is negated by the ball bearing although the drsa bearing rolls a little more easily than say a roller bearing.
The original ball and roller bearing combination gave a radial load capacity and axial capacity which with similar internal radial clearances the bearing loads would be shared reasonably well.
The axial movement due to radial clearance in the single row deep groove ball bearing would be somewhere about 3 to 4 times the radial clearance - around 2-3 thou mounted and the engine survived on this end float until the pair of angular contact ball bearings were introduced, probably giving about 0 to 1 thou end float with standard bearings nowadays.
The suggestion about the flanged outer ring rear roller bearing retaining oil could be correct but it would seem to be difficult to remove the plain inner ring from the crankshaft.