SPEED REDUCERS–COMMONLY USED TERMS (part 3)
OVERHUNG LOAD
A force applied at right angles to the shaft, beyond its outermost bearing is the overhung load. Both the input and output shaft of a speed reducer can be subject to an overhung load. Such a force is a shaft bending under load resulting from a gear, pulley, sprocket or other external drive member. Besides the tendency to bend the shaft, the overhung load (the radial force on the shaft) is reacted to by the shaft in its bearings. Therefore, the overhung load creates loads that the bearings must be able to support without damage.
SERVICE FACTORS
A numbering system that identifies the loads that must be considered in selecting a speed reducer is the service factor.
Service factors vary according to the type of service for which the reducer is to be used, the kind of prime mover involved and the duty cycle. The service factor can be a multiplier applied to the known load, which redefines the load in accordance with the conditions at which the drive will be used, or it can be a divisor applied to catalog reducer ratings, thus redefining the rating in accordance with drive conditions.
REDUCTOR
Gear's registered trademark for a speed reducer having a projecting input shaft suitable for mounting a coupling, sprocket, pulley or gear is a reductor.
RATIOMOTOR™
Gear's registered trademark for a motorized reducer consisting of a flanged reductor and face mounted motor assembly. A Ratiomotor is sometimes referred to as a gearmotor.
SELF LOCKING ABILITY
Gear Series reducers, under no conditions should be considered to hold a load when at rest.
BACK-DRIVING
Is the converse of self-locking, depending upon reduction ratio and many other variables, it is difficult to predict the back-driving capability of a Gear Series reducer. Worm gear reducers are not intended to be used as speed increasers. Please consult the factory for back-driving applications.
