The Epicyclic Gear Units have been developed to enable students to
carry out investigations concerning epicyclic gearing in simple and
more advanced forms.
A version of this apparatus is the Coupled Epicyclic Unit Ref SD-4.17
which uses two standard speed unit or a forward and reverse unit.
Recently introduced, the Three Speed Epicyclic Gearbox Ref SD-4.18
provides two forward speeds and reverse.
A bracket fitted with a spring balance which enables the student to
measure the holding torque on each annulus can be supplied as an
optional extra (Ref SD-4.18a).
Bearings are used extensively throughout these units to reduce
frictional losses to a minimum.