[TowerTalk] Thrust Bearing

[Wilson]

There are lots of kinds of thrust bearings, including the ones on the front wheels of cars, which are for a combination thrust/radial loads.
The pillow blocks with ball bearings are for minimal thrust loads and will wear rapidly.  

http://www.bearingson.com/Category/4-bolt_flanges/cast_iron_4-bolt_flanges/ucf_series/default.asp?page=2&SortType=0


Here are some true thrust bearings:
http://www.timken.com/en-Us/products/bearings/productlist/roller/thrust/Cylindrical/Pages/TP.aspx#

You can quickly recognize a ball thrust bearing, at least many of them, because their outer circumference is split, so you see the balls when you look in radially.
Think of two big washers, with balls between, like the ball race in your rotator.

http://en.wikipedia.org/wiki/Thrust_bearing

I think the term “thrust bearing” is widely misused.  Thrust is parallel to the axis of the mast.  A thrust bearing carries the weight of the mast and antenna.
Many top bearings are just for radial force, the side loads caused by wind, unbalance.

WL