The basic principle.
A traction machine combines the elements needed to turn a drive sheave. Depending on design, it includes a motor, gearing, bearings and a brake, or a gearless motor directly coupled to the sheave.
The sheave transfers force through traction at the suspension contact. It does not simply wind all the rope onto a drum. Rope tension, contact geometry and condition affect its ability to transmit force.
Motor speed is not car speed.
A gearbox can reduce speed before the sheave; sheave diameter converts rotation to rope travel; roping ratio then relates rope travel to car movement.
Follow the relationship.
- MotorProduces shaft torque.
- MachineTransmits torque directly or through gearing.
- SheaveActs on ropes or belts.
Connect it to the lift.
The brake and drive perform coordinated but different duties. Noise or vibration may originate in the motor, bearings, gearing, sheave contact or supporting structure. Machine condition is assessed as an assembly.
A closer look
Machine-room-less describes equipment location rather than one universal motor or suspension design. Layout and machine type are separate characteristics.
Check your understanding
Does “gearless” mean there is no mechanical brake?
Reveal the explanation
No. Removing a gearbox does not remove the need for the installation’s braking functions.