CONTROLLED COUPLING HYDRA-MATIC
Note: Two sprag clutches are used in this transmission. How they
function to keep planetary members from rotating, and thus providing
reduction, is covered under discussions of the front and rear units.
|b. The fluid clutch (or front unit coupling). This unit consists of a drive torus, driven torus, and cover. The toruses, about ¼ inch apart, are connected to independent shafts. They are enclosed in an oil tight housing consisting of the drum shell and cover.|
Valves in the front cover control the
filling and draining of the clutch. When the valves
are closed, the clutch fills with oil. When the valves are open, oil drains out of the unit.
When the fluid clutch is filled with oil, power is transmitted from the drive torus to the
driven torus. When there is no oil in the unit, power cannot be transmitted.
c. The rear multiple disc clutch. This
clutch consists of a hub (integral with the intermediate shaft),
drive plates, driven plates, drum, piston, and release springs. The drive plates, mounted on the
hub, have internal serrations which engage with splines on the hub. The driven plates have outer
serrations which engage with splines in the drum. All the plates are free to move independently.
To page 91