HARLAND DRIVE

219

These modern units with gears running in oil, on shafts equipped through-
out with roller bearings, occupy a minimum amount of space and are practically
noiseless in operation.

Most machinery manufacturers make a range of units of various power
capacities, each with variations in gear ratio. Their design allows ample
adjustment to be made to take up wear in the taper roller bearings, and also
has ball bearings fitted for the cone pulley to revolve upon when the unit is
not transmitting power.

[ftrfW BgterJMg O. Ltd.

88.-HAJULAND DOTE ON 2OO

Multi-Motor Drive.—The Harlaad drive (fig- 88) is of the sectbnalised
type with a motor on each section, die motors being coupled through double
helical gears to the paper machine driving-in shafts. For the purpose of main-
taining relative desired speeds on the motors, a master reference is provided.
In die original system a ligfct sliait was ran along the full length of the machine,
this shaft being driven from die dryer section or by a separate master motor.
fa* die iip-to-date version an 'electrical master shaft' is employed, giving greater
fkadbifcy of layout and control
Eadb section is provided with a differential regulator, one shaft of tfae
differential g*ais bong coupled to a small synchronous motor running
synchronism widi the master alternator. The second shaft of die