A UK aggregate producer has recently installed a new in-feed conveyor to deliver stone to a large conveyor at a roadstone quarry in the Pennines, the site is on the Great Whin Sill, and impressive outcrop of rock provides the foundation for much of Hadrian’s Wall. When the new conveyor started to cause a build-up of material on an adjoining conveyor Deritend RMB was called in to provide a solution. Utilising its expertise, Deritend RMB was able to specify, deliver and install a David Brown Series G reducer gearbox. The new gearbox was able to increase the conveyor’s speed and match the load rating whilst maintaining the same input power of 75kW.

For a large aggregates company to function efficiently it is vital that all of its sites run at their optimum. The company initially installed the new feed conveyor to deliver stone at its optimum operating speed of just over 2 metres per second delivering 700 tonnes per hour. This speed and feed exceeded the capacity of the older feed conveyors filling the storage bins resulting in a build up of material. The secondary conveyor was originally driven by a 75 kW electric motor running at 1440rpm with a worm box producing an output speed of 36rpm. This produced a conveyor speed of just over 1 meter per second - this needed to be matched to the 2 meters per second of the new conveyor - in the most economic way possible.

RMB calculated that conveyor 5 needed to run at 68.75 rpm to reach the desired speed, it was also considered important not to increase the original input of 75kW as this would increase installation and running costs. The solution was to be found in David Brown’s latest G series range of bevel-helical medium/heavy duty industrial gearboxes. The gearbox is a market leading design, offering top quality, features such as cooler running and ratio flexibility as well as high performance and cost competitiveness.

With fine pitched teeth creating a greater contact ratio there is a dramatic increase in strength in a Series G often resulting in a more efficient gearbox than others of its type. All the gears are case hardened and profile ground which leads to better durability. The gearbox is designed to be easily maintained and has a quadruple seal arrangement, developed to keep dirt out and oil in.

ISO 9002 approved Deritend RMB is the only UK company to stock the David Brown G series gearbox in modular form. Holding £1 million in gearboxes and related stock, and well over 600 David Brown components, RMB are the only company to hold the David Brown ‘Swift Centre +’ status on 24hr basis. It was able to supply the customer with an integrated drive package, the box supplied with single extension output shaft, anti-runback device, cooling fan and cowl.

John Harrison speaking for Deritend RMB said “We take great pride in anticipating the needs of our customers. In this instance we were able to install a gearbox that delivered an increased output speed to the high load conveyor, while maintaining the same input power of 75kW.”