In alt.home.repair, on Sat, 17 Aug 2019 08:12:43 -0700 (PDT), A K
wrote:

On Friday, August 16, 2019 at 2:23:43 AM UTC-5, trader_4 wrote:
On Friday, August 16, 2019 at 1:54:36 AM UTC-4, Andy wrote:
I have a bench grinder that i bought in 1986. The label says "all ball bearing motor." Is that motor different than other motors?

Generally there are two types of bearings, ball or sleeve and ball ones cost more and are better for many applications, including that they can be replaced in many cases if they wear out. On the other hand it a sleeve bearing lasts the life of an infrequently used, not so expensive thing, it can be well suited to the application.

thanks trader_4 for the detailed info.

Andy

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.