DAVYMARKHAM says it continues to refine and develop its mine hoisting systems.
The business claims in recent years the drive toward ever-improving efficiency and reliability as well as the need to dig deeper to exploit mineral resources has led to significant changes in their design and technology.
The manufacturer says the performance and safety of the systems are critical to mining operations, since they help determine productivity and hence profitability.
DavyMarkham says it has focused its design and engineering resources on refining and developing its double drum technology. It has re-designed bearings and drum brakes which prolong service life, engineered precision grooves, crossovers and risers that ensure optimum coiling behaviour, and fabricated drum assemblies in halves for easier shipping and handling on site.
It has also developed multi-channel brake control systems, each fully independent electrically, mechanically and hydraulically, which ensure that should one brake channel fail, the remaining brake clusters remain under correct application control to stop the hoist safely.
In compliance with SABS, it has designed the multi-caliper disc braking system to reduce dynamic rope loads to a minimum, employing proportional control valve technology to prevent sudden shock loads to passengers in the cage and optimise the rope safety factor.
Similarly, it has moved from DC type motors to AC drives with cycloconverters or converters based on direct torque control, while motor outputs themselves have increased in line with growing payloads and deeper shafts. The AC drives are said to be more reliable and easier to maintain.