Page 281 - Steam Turbines Design, Applications, and Rerating

260 Chapter Thirteen

The VORECON works on the principle of power splitting using a
superimposed planetary gear unit. The design with horizontally split
housing is compact and space saving with the following individual ele-
ments highlighted in Fig. 13.18:
A. Hydrodynamic variable-speed coupling
B. Hydraulically controlled lockup clutch
C. Hydrodynamic torque converter
D. Hydrodynamic brake
E. Planetary gear, fixed
F. Planetary gear, revolving

The individual components lie coaxially on the shaft center line.
Working and lube oil is pumped from a common oil tank by a mechan-
ically driven pump, as is current practice for variable-speed units. The
oil tank can be freestanding. Since all the functional changes within
the VORECON are made solely by filling or draining the hydrody-
namic components, smooth changeover from one component to another
is ensured. This can be achieved by using fixed solenoid valves and
standard electromechanical or pneumatically operated actuator. The

Figure 13.18 VORECON hydrodynamic variable-speed drive. (Voith Transmission, Inc.,
York, Pa.)