Bearings were designed to prevent wear and friction between parts, which operate on, or against each other.
[Fig. 139] shows three types of plain bearings. A, the split type of plain bearing, is used widely by the manufacturers of engines as main bearings to support the crank shaft and at the large end of the connecting rod. B is a cylindrical type of plain end bushing, used to support light shafts in end walls. C is a center or sleeve type of plain bushing.
Fig. 139. Plain Bearings or Bushings
All three types of plain bearings described above will stand unusually hard use, but must be kept well lubricated or run in an oil bath to prevent frictional heating and excessive wear. [Fig. 140] shows two types of shims used between the retainer jaw of a split bearing, which allows the wear to be taken up when the bearing gets loose and begins to pound. The shims may be either solid or loose leafed, and are of different thickness. The loose leafed shim has an outer casing, which contains seven to ten metal sheets of paper-like thinness, which may be removed to the exact thickness required for an accurately fitted bearing.
Fig. 140. Shims
Fig. 141. Bock Roller Bearing
[Fig. 141] shows the Bock type of radial and end thrust roller bearing. The end of each roller is provided with a section of a perfect sphere which rolls in unison with the tapered rollers and makes the end contact practically frictionless. The advantage claimed for this type of bearing is that it embodies both the ball and roller bearing strength and reduces the friction on the roller and thrust end to a minimum. This type of bearing is used in the hub of the wheel, which must be cleaned and well packed with a medium grease every thousand miles. The bearing is best cleaned by dropping it into a container of kerosene and scrubbing it with a stiff paint brush. Do not run the car with the hub cap off.