What is the difference between cable drum, traction and hydraulic drives?
All home elevators use cables or chains to move the cab from one level to another, the difference is in how those cables or chains are propelled… Hydraulic units use a hydraulic piston or jack to push on a loop of cable connected to the car that moves the car up at a 2:1 lift ratio as the piston extends. Because of the 2:1 lift ratio, a jack hole is not needed like you may see on some direct drive commercial elevators. Winding drum units simply have the support cables wrap on a large spool or drum to move the car up and down. Traction drive units use counterweights to balance the weight of the car. The motor simply moves the weights down as the car goes up via cables or chains. Other differences: In years past, a big difference between the machine types for the home owner was that hydraulic elevators offered two features that others elevator drives did not… “emergency battery lowering in case of power failure” and “variable speed soft starts & stops”. That has changed! Today, nearly al
