bronze bearings

My husband is a welder in a tanker ship.  Asides of being a welder, he also knows how to repair cars especially off-road rides.  When he finishes work, I always ask how does it go.  He usually answers that there is a certain bearing that is loose.  Well, I do not know that kind of problems that he fixes.  All I know that he is very good when it comes to cars.  So, to understand more of what is bearing, I search it on the internet. A bearing is any of various machine elements that constrain the relative motion between two or more parts to only the desired type of motion. This is typically to allow and promote free rotation around a fixed axis or free linear movement; it may also be to prevent any motion, such as by controlling the vectors of normal forces.  There are also different types of bearings.  These include ball bearings, roller bearings, ball thrust bearings, roller thrust bearings and Tapered Roller Bearings.  There are also what you call bronze bearings. A common plain bearing design utilizes a hardened and polished steel shaft and a softer bronze bushing. The bushing is replaced whenever it has worn too much.