Everybody overlooks the propshaft angles !
Hi Mark,
That is the angle subtended by the axes of each section that I mentioned in my post and is explained mathematically within the attached pdf.
Ron, I would need that translated into English as she is spoke by us lay persons. If a shaft with 2 ujs can handle, in phase, input and output axes displaced in one plane (eg vertical, which I think is true?), does another displacement (ie horizontal) cause problems that need the ujs out of phase?
When I used to do race car scrutineering it was common to see driveshafts on open wheelers - short, with sliding joints - out of phase, and different from one side to the other.
Hi John,
Imagine two shafts joined by a universal joint. When the axes of each shaft is within the same plane, that is to say that they align perfectly, turning the input shaft to the universal joint means that the output shaft turns exactly in the same way. Now, if we change that orientation by purposely introducing an angle between the input and output shafts in any direction, then as you turn the input shaft you will feel the rotation of the output shaft is no longer the same. For every 360 degrees of rotation of the input shaft, the output shaft will both speed up and slow down which seems impossible, but the impossible happens. The greater the angle between the two shafts, the more pronounced these accelerations will be. To eliminate the effects that not having the two shafts aligned means we need to introduce a specific amount of phase shift into the placement of another universal joint at the far end of the driven shaft. This is what the Rover engineers devised, given that sliding joint, the tailshaft, and the pinion do not all lie in the same plane, i.e., their axes do not align. This phase shift takes into account the speeding up and slowing down of the tailshaft meaning that the pinion will now spin with the same speed throughout each 360 degrees of revolution as the sliding joint.
Ron.