What is used to ensure smooth operation of heavy elevator doors?

Counterweights play a crucial role in the smooth operation of heavy elevator doors by balancing the weight of the door itself. When installed properly, counterweights minimize the amount of force required to open and close the doors, making the operation smoother and more efficient. The counterweights counteract the gravitational pull on the heavy doors, thus reducing the wear and tear on the door operating mechanisms, resulting in a longer lifespan and better system reliability.

Other methods, such as lubrication with grease, can help with the sliding or pivoting movements of the doors, but do not specifically address the balancing aspect that counterweights provide. Similarly, hydraulic fluid is found in hydraulic door operators and enhances motor functions, while ball bearings can facilitate smooth movement; however, they do not replace the fundamental necessity of counterweights for managing the heavy door dynamics effectively.