The 4QMET (Continuously Variable Electronic Transmission) is
a transmission that enables a motor to always operate at a constant
speed and at the motor’s peak efficiency, while providing
controlled output speed and torque conversion. Conversion of
constant motor speed to variable output speed and torque is
accomplished electronically. Therefore all efficiency benefits
are fully captured in energy savings.
The 4QMET is extremely
well suited for elevator applications where either geared or gearless
machines are used, providing the best of both worlds. The 4QMET enables
the high torque and quick acceleration required for geared application,
while at the same time enabling use of high maximum travel speeds
as typically provided by gearless machines. As the graph below shows,
by providing the most torque at the lowest speeds, the 4QMET enables
use of a smaller motor than would otherwise be used.
less torque is required during high speed travel, the 4QMET enables
the high motor speed to be passed through to the sheave, ensuring
the peak maximum speeds delivered by gearless systems.