As large mine conveyors increase in size the installed capacity also increases. If the installed power is greater than 3 MW then a gearless drive pulley can reduce power demand by eliminating the need for speed reducers (gearboxes) and increasing system reliability by eliminating high maintenance pieces of equipment.

PROK has been a world leader in manufacturing of conveyor pulleys for over 50 years. Our engineering team continues to evaluate the performance of PROK pulleys in the field and review the latest design and manufacturing methodologies to ensure that PROK pulleys are always designed and manufactured to best practice.

The end disc is the most complex part of a pulley. The end disc must transmit the loads from the shaft into the pulley shell, while at the same time allowing the end disc to flex and ensure that the stresses in both the shell and the shaft are maintained within acceptable levels. The material and geometrical shape of the end disc is therefore critical and a full and detailed understanding of exactly what loads are being applied to a pulley in operation is required.

Due to the high loads incurred with direct drive pulleys PROK utilise profiled “Tee Shaped” end discs to achieve the required outcome. A single Tee Shaped end disc can weigh in excess of 6,000 kg. PROK’s extensive manufacturing experience will ensure that PROK end discs are fabricated to the exacting tolerances and specifications that are required for such a highly loaded pulley.

The shells used on direct drive pulleys are typically very large and therefore the quality of the fabrication needs to be accurately controlled.

By utilising computer controlled plate rolling processes, PROK is able to accurately control the rolling and welding process which results in a dimensionally accurate and high quality pulley shell.

The selection of the correct locking element requires a detailed understanding of how the assembly operates and what critical factors need to be considered in the design and selection.

PROK, in conjunction with the world’s leading locking element manufacturers, have worked together to optimise this selection process using the latest design technology.

The rotor of a direct drive pulley is fitted directly onto the shaft of the pulley. Therefore deflection must be accurately controlled in all operating conditions. As a result the mass of a direct drive pulley shaft can be over 35,000 kg.

PROK’s experience in the manufacture of large crusher main shafts and other heavy fabrications ensures that PROK is a market leader in this area. PROK can design and manufacture any size pulley shaft that is needed to the highest of specifications.

The PROK Hot Vulcanised Ceramic Lagging (HVCL) system is ideally suited to increase the service life of high load conveyor pulleys. Ceramic lagging has been proven to provide benefits over plain rubber lagging. However as pulley loads and belt tensions increase the more traditional lagging solutions have not always been able to meet the increased demand.

PROK HVCL solves these problems. By using a hot vulcanisation process to bond the lagging to the pulley shell and by utilising a specialised process where the tiles are encapsulated within the backing rubber with a propriety bonding system we ensure that the lagging can operate in high tension applications. The PROK HVCL therefore provides the ultimate in lagging systems for Direct Drive conveyor pulleys.

PROK work with the world’s leading bearing manufacturers and suppliers to ensure that the pulley bearing assembly will provide an optimum service life.

By utilising features such as sealed bearings and specialised bearing housing sealing system technology, PROK pulleys are able to operate in the harshest of environments.