Where are thrust bearings located on an elevator machine?

Thrust bearings are critical components of an elevator's mechanical system, specifically designed to support and stabilize rotating shafts. In the case of worm gear systems, which are commonly used in elevators, thrust bearings are placed on either or both sides of the worm shaft. This positioning allows the thrust bearings to effectively absorb axial loads produced by the worm gear during operation, ensuring smooth and controlled movement. This arrangement is essential to prevent excessive wear and potential mechanical failure of the elevator system, contributing to overall safety and reliability.

The other options do not accurately describe the location of thrust bearings. For instance, placing them at the base of the elevator shaft or on the sides of the elevator car does not align with how they function or are installed in the system. Similarly, having them above the elevator machine room would not provide the necessary support directly related to the worm shaft's operation. Therefore, understanding their correct location is vital for maintaining elevator performance and safety.