A. Ball bearings offer higher limiting speeds and rotational accuracy than roller bearings, therefore, they should be preferred for high-speed applications.

B. With the same inner diameter, a smaller outer diameter results in smaller rolling elements. This reduces the centrifugal inertial force exerted by the rolling elements on the outer raceways during operation, making them suitable for higher speeds. Therefore, for high-speed applications, bearings with smaller outer diameters within the same diameter series should be selected. If a single bearing with a smaller outer diameter cannot meet the load requirements, it can be used in parallel with other bearings of the same type, or a wider range of bearings can be considered.
C. The material and structure of the cage significantly affect the bearing speed. Solid cages allow for higher speeds than stamped cages, and bronze solid cages allow for even higher speeds.
Generally, for higher speed applications, deep groove ball bearings, angular contact bearings, and cylindrical roller bearings are preferred.
For lower speed applications, tapered roller bearings can be used.
The limiting speed of tapered roller bearings is generally about 65% of that of deep groove ball bearings, 70% of that of cylindrical roller bearings, and 60% of that of angular contact ball bearings. Thrust ball bearings have a low limiting speed and can only be used in applications with relatively low speeds.