33005 Taper Roller Bearing 25x47x17mm

 1.  the introduction of tapered roller bearings 

Tapered roller bearings are designed such that their conical rollers and raceways are arranged so that all elements of the roller and raceway cones meet at a common apex on the bearing axis. The rollers are guided by the contact between the large end of the roller and the rib on the inner ring (cone). 

This construction provides a high capacity for radial loads, axial loads, and combined loads. The larger the contact angle, the greater the loading capacity becomes. When a pure radial load is placed on the bearing, an induced load in the axial direction is also generated. So, these bearings are generally used in pairs opposing each other. Proper running clearance or preload can be obtained by adjusting the distance of the two bearings against one another. Since the inner (cone) and outer (cup) rings are separable, each ring can be mounted individually, allowing both rings to use tight fitting practices, if desired. 

Both metric and inch systems are standardized by bearing series and both systems are widely used. The metric system is specified in ISO, and the inch system is standardized in AFBMA standard. 

2.33005 bearing detailed description