SCIENCE AND TECHNOLOGY ENGLIAH FOR MECHANICAL ENGINEERING Characteristics 1. Ball bearings have rolling elements in the form of balls which in all but the most inexpensive types are held in cages, separators, or retainers, and inner and outer grooved races 2. Roller bearings have mainly cylindrical, conical,or barrel-shaped rollers instead of balls, but are otherwise quite similar to ball bearings 3. Needle bearings usually have neither an inner race nor a cage. The needles are retained by integral flanges on the outer race. Transitional types between roller and needle bearings are found in many catalogsSCIENCE AND TECHNOLOGY ENGLISH FOR MECHANICAL ENGINEERING Characteristics l. Ball bearings have rolling elements in the form of balls, which in all but the most inexpensive types are held in cages, separators, or retainers, and inner and outer grooved races. 2. Roller bearings have mainly cylindrical, conical, or barrel-shaped rollers instead of balls, but are otherwise quite similar to ball bearings. 3. Needle bearings usually have neither an inner race nor a cage. The needles are retained by integral flanges on the outer race. Transitional types between roller and needle bearings are found in many catalogs