One-way roller clutch USNU series

without internal bearingsindexingbackstop

The USNU Series freewheels are not self-centering. It is therefore necessary to place one or two bearings next to the freewheel so that the outer race can rotate centrally to the inner race. USNU freewheels have ball bearings with the same dimensions as the 63.. series. The torque forces are transmitted from the shaft to the inner race by means of a key and from the outer race to the seating by means of front pullers or by means of an interference fit if the seating tolerance is made a K6. Shaft tolerance must be either h6 or j7; the tolerances for the seating must be either H7 or F7. When front pullers are not used, the seating tolerance should be K6. Before being put onto service, the freewheels must be lubricated with suitable lubricants following the instructions given on page 12. Oil lubrication is essential when a high number of rotations in neutral is reached.