The initial selection of an elevator machine is based on several factors, such as car speed, number of floors to be serviced, operating efficiency, maintenance requirements, car ride characteristics, and costs. If the hotel has 15 or more floors, the gearless traction elevator machine is normally recommended.
All of the above factors, except for its initial cost, are very favorable when compared to other elevator machines. The sheave V driving motor is direct current & is attached to sheave elevator machine must have either a separate alternating-current motor direct-current generator (motor and generator or MG set) to supply direct current to the sheave driving motor or a solid-state control. Solid-state control systems are generally replacing. MG sets.
A second elevator machine is the geared traction machine. A DC or AC motor drives a series of gears, and the last gears in the series is attached to the sheave. The AC driving motor is not generally used for passenger elevators.
This elevator machine provides for low to medium car speed. Car ride characteristics are not as good as the gearless machine, machine requirements are higher because of the driving gear system, but they cost less than gearless machines. The gear driving system requires considerable maintenance.
Proper lubrication is scheduled as preventive maintenance for the gear drive. Gears wear with use and must be adjusted to eliminate car jerks and produce a smooth car ride. This adjustment should be scheduled as preventive maintenance; adjustment procedures are relatively simple to perform.