Held and Float
Craft Split Roller Bearings, in all shaft sizes and series, are manufactured in two types—held and float (non-expansion and expansion). They are manufactured as separate bearings to solve the problem of some applications needing to allow for shaft axial movement (parallel to the shaft) and others needing to be able to hold the shaft in a fixed axial position.
Held Bearing (HD)
The held bearing accepts both radial (perpendicular to the shaft) and axial (parallel to the shaft) loads. The main purpose of the held bearing is to “anchor” a shaft in position, to prevent shaft drift during operation, and absorb thrust or “side” load imposed by the equipment in operation. The held bearing is normally mounted on the drive side, or drive end of a piece of equipment, directing shaft expansion away from the drive. In applications where a high thrust load is expected or realized, please contact our technical department for advice on proper bearing selection.
Float Bearing (FL)
The float or “expansion” bearing is designed to take radial (perpendicular) load only. It is designed to allow for thermal growth of a shaft during operation. The floating bearing is normally mounted opposite the drive end of a shaft and used in conjunction with a held or fixed bearing when both bearings are mounted on a common shaft section.
In most applications, one of each type bearing is mounted to each solid shaft section. In the instance of long line shafting, one held bearing is normally used with the rest being floating type. Exact placement of the bearings can vary. When using both floating and held type Craft bearings in an application, be sure to maintain individual bearing components of each type separately as they are shipped. Bearing parts are not interchangeable, and individual bearing components are manufactured—and matched—at our plant for proper internal clearance and fit. Mixing components during installation may cause less than desirable performance or premature failure.