Noise control of machine room-less elevators: the practice and effect of vibration reduction technology

Analysis of noise sources
The noise problem of machine room-less elevators is primarily caused by the operation of its core component, the elevator host. As the power source for driving the elevator up and down, the internal motor, reducer and other mechanical parts of the elevator host will vibrate when running at high speed. These vibrations are transmitted to the surrounding structure through the installation foundation, thereby forming noise. In addition, as an important part of the elevator safety system, the speed limiter is activated when the elevator is overspeeding, and its operation process will also generate certain vibrations and noise. Although electrical control equipment, including inverters, contactors, etc., are relatively quiet, they still emit subtle electromagnetic noise and mechanical vibrations when working.

Vibration reduction treatment measures
In order to effectively alleviate the noise problem of machine room-less elevators, the industry has adopted a series of vibration reduction treatment measures to reduce vibration conduction from the source, thereby reducing the generation of noise.

Installing shock absorbers: Installing high-performance shock absorbers under the main vibration sources such as elevator hosts and speed limiters is a direct way to reduce noise. Shock absorbers are usually made of materials such as rubber, springs or hydraulics, which can effectively absorb and disperse the vibration energy generated by the equipment and reduce its transmission to the surrounding structure.
Use vibration damping pads: fill vibration damping pads or vibration damping materials, such as high-density rubber pads, polyurethane foam, etc., where the elevator equipment contacts solid objects such as walls and the ground. These materials have good elasticity and damping properties, can effectively isolate vibration and reduce the propagation path of noise.
Rigid connection to elastic connection: changing the original rigidly connected equipment components (such as cable trays, control cabinet brackets, etc.) to elastic connections, such as using rubber soft joints, spring hangers, etc., can effectively alleviate the structural resonance caused by equipment vibration and further reduce the noise level.
Structural optimization and sound insulation treatment: In addition to the above direct vibration reduction measures, the sound insulation performance of the elevator shaft can be improved by optimizing the elevator shaft structure, adding sound insulation boards or sound insulation coatings, etc., and reducing the interference of noise on the external environment.
Practical effects and future prospects
Through the implementation of the above vibration reduction treatment measures, the vibration and noise problems of machine room-less elevators have been significantly improved. Residents' feedback shows that the noise during elevator operation has been significantly reduced, and the comfort of the living environment has been improved. At the same time, these measures also help to extend the service life of elevator equipment, reduce the failure rate caused by vibration, and improve the overall operating efficiency of the elevator system.