Robot Mechanisms and Mechanical Devices Illustrated - Profe Saul

84 Chapter 2 Indirect Power Transfer Devices
surfaces at a high rate. This drive has been used with some success in
walk-behind lawn mowers, but its life in that application is usually
only a couple seasons. Figure 2-13 shows one of several versions of a
friction drive.
CONE DRIVE NEEDS NO GEARS OR PULLEYS
A variable-speed-transmission cone drive operates without gears or
pulleys. The drive unit has its own limited slip differential and clutch.
As the drawing shows, two cones made of brake lining material are
mounted on a shaft directly connected to the engine. These drive two
larger steel conical disks mounted on the output shaft. The outer disks
are mounted on pivoting frames that can be moved by a simple control
rod.
To center the frames and to provide some resistance when the outer
disks are moved, two torsion bars attached to the main frame connect
and support the disk-support frames. By altering the position of the
frames relative to the driving cones, the direction of rotation and speed
can be varied.
The unit was invented by Marion H. Davis of Indiana.
Figure 2-13 Cone drive operates
without lubrication.