In article , NONONOmisc07
@bigfoot.com says...

Worth noting that car engines have only sleeve bearings, but they get
long life out of them by making them of special material and by
inserting oil under pressure between the bearing and the rotating
shafts. My guess is that roller bearings and ball bearings wouldn't
work at the high rpm of car engines, or at least they wouldn't work
better, though maybe i'm wrong and some engines I'm not acquainted with
do use them.

OTOH, car wheel bearings are roller bearings, and they are replaceable.
When one of your wheels rumbles when the car is moving, it may be the
wheel bearing.



Ball bearings work fine at engine speeds. They only run around 3000 rpm
or less normally, but up to 5000 t0 10000 rpm for short periods of time.

One reason for the ball bearings in wheels is it is very difficult to
put oil to them under pressure.

It it the oil and grease that keeps the metel parts seperated so they do
not wear.

Electric motors often run at 3600 rpm or more with ball bearings and
grease.