a transfer of energy or power straight from the engine crankshaft or motor shaft to the prop, without a clutch
A conventional motor has direct drive.
In case of the direct drive a stub shaft is fastened direct to the crank-shaft and is fitted with a double thrust bearing.
What engineers call a "direct drive" is substituted in its place.
When direct drive cannot be had, a belt must be used, either from a main shaft, or a countershaft.
The change from the direct drive to gear drive, or vice versa, can be accomplished in approximately one hour.
Standard practice in new construction calls for holding speed by direct drive from a specially-wound ehrenhafter.
But the man did not hear him, for he was yanking into place the lever that enabled him to run on direct drive for fourth speed.
The advantages of direct drive are so many that it should be used wherever possible.
The construction of the motor is such as to permit of the application of a direct drive.