Vibration Systems & Solutions vibration system for testing emergency pull switches

Vibration Systems & Solutions (VSS) helped to design a vibration system that tested if emergency pull switches could withstand the vibrations inherent in conveyor systems at mine sites.

One of the prime concerns on any mining or quarrying site is safety, especially around moving parts. Conveyor belts are good for moving large volumes of material, be it iron ore, cereals or road base, but they also need some method of stopping them quickly in case of emergency. Running alongside conveyors are cables which, when pulled, cause a switch, usually some distance away, to trip and stop the conveyor. While the switches have to be sensitive to the operation of the cable, they must also be able to withstand the vibration inherent in the conveyor system due to various factors, such as the motion of the conveyor idlers.

VSS was asked by a client to help in the design of a vibration system to allow the switches to be tested under various vibration parameters, such as frequency and force of vibration. A vibrating test table with a single vibrating motor and a variable frequency drive (VFD) was designed to replicate the conditions on mine site conveyors. The use of a single motor, from VSS’s principals NetterVibration, meant that there was a slight sideways movement to the table top, as well as the usual vertical action, to more accurately simulate actual conditions. The VFD was supplied by the client, who is allied to a company making these units, and this can adjust the motor drive to give varying frequencies and forces of vibration.

The client then visited mine sites with a NetterVibration VibroScanner vibration measuring system to determine the vibration in their conveyors. The system provided accurate frequency, amplitude and acceleration measurements, and these data were replicated on the client’s test table to ensure that the switches being supplied could withstand these vibrations and did not give false tripping.