VERIFICATION OF BRAKING MECHANISM OF HOISTING DEVICE BLIND SHAFT NO.11 OF THE MINING PLANT LONEA

Every extraction machine is endowed with a braking system while ensure the right movement of the hoisting vessels, or allows to stop the machine in a certain position of the vessels (brake tests) and the automatic brake device, independently of the operator will, in one of the following situations, considered to be perturbations or damages: tension absence, pressure drop of the working fluid in the braking system circuit, the overraising of the extraction vessels, exceeding the limit speed, overload etc. (safety–braking). Speed decrease made by the brake system must be between 1,5–5 m/s2 and the delay length of the brake (from the action release till the effective application) at the most 0,7 s. Constructively, the brake system consists of two components: the working mechanism and the actuating system. Upon the working system, the common brakes can be with disk or with shoes, and from the point of view of actuation, can be with weights and, spring assembly, pneumatics, hydraulics and combined. Braking–mechanism diagnosis for the mi-ning hoisting machines consists in establishing the real safety factors when the safety–brake is applied and when operating brake is applied too. The experimental measurements have been made at the Auxiliary Blind Shaft no.11 at Lonea Mining Plant in order of examination and regulation the hoisting machine.