Bonfiglioli states: “Large gearboxes are used in a wide range of application areas. The requirements are however almost completely the same and can be summed up very quickly – the gearboxes should be as powerful and robust and with the longest service life possible, however be small and variable for integration in the machine.” These were also the criteria that were important when selecting the gearbox for the Transmin Low Profile Feeder (LPF), which is used by the company Sun Metals for high grade zinc ore transport from the mine to the processing plant. The selection was made quickly with a Heavy Duty HDO gearbox from north Italian drive specialist Bonfiglioli selected as it satisfied all the requirements needed.The LPF of the Western Australian company Transmin is a hybrid belt feeder/apron feeder which delivers the advantages of both technologies, “plus additional benefits unique to Transmin, including the ability to incorporate a change of direction using a bend transition. Unlike conventional heavy-duty belt feeders, the belt itself is not subject to high tension forces, which means a lower profile can be achieved. In addition, unlike apron feeders, a separate spillage clean-up conveyor is not required, again saving space and the cost of civil works.”The open pit zinc mine is very space-limited. “For this reason, only one compact feeder solution that fulfilled the requirements came into question. According to the manufacturer specifications, the LPF has currently the lowest possible profile available in a high capacity feeder, typically no more than 1 m from belt top surface to underside of footplates.”“For these compact sizes, a compact and yet reliable gearbox is indispensable for the LPF in order to guarantee continuous operation to our customers such as Sun Metals”, explains Tony Warren, Lead Design Engineer, at Transmin. The logical choice for the gearbox for the LPF, which in the plant handles up to 400 t of high grade zinc ore per hour, was the high-performing Heavy Duty HDO 170 helical gearbox produced by the drive specialist Bonfiglioli with a maximum torque of 190,190 Nm. The complete range of proven gearboxes consists of ten sizes, from 8,990 to 209,900 Nm. The HDO 170 gearbox, which is suitable for noise and vibration-free operation, is powered in this case by a 75 kW motor with 12,700 Nm of torque. At Sun Metals, the feeder is located below a large hopper, which is filled from above with the ore by side tipping trucks. The Transmin feeder then transports the ore to the process plant, where it then is refined into high-quality zinc metal for galvanisation and other markets.Bonfiglioli’s compact HDO gearbox series, which stands for Heavy Duty Orthogonal, consists of performance-optimised ground splines, quality bearings and spheroidal graphite iron housings, which guarantee high levels of performance and stability, even in the harshest environmental conditions as found in the zinc open pit. “As a bevel gear with a bevel gear stage on the input side, the robust Heavy Duty Bonfiglioli gearboxes are able to cover large power ranges in applications such as mining and extraction industry. Like the small design sizes, also the 170 gearbox has a wide selection available of drive shafts (solid and hollow shafts, shrink discs) and input variants. Just as for the entire gearbox range, options are available for the oil supply as well as various heating and cooling possibilities that meet application requirements. In combination with the powerful motors and couplings, the HDO gearbox series is also available as a motor swing. The HDO gearbox series is the response to the request for gearboxes with high transmission ratios. The 170 gearbox is used above all in heavy industry.”In addition to the convincing technical features, such as the high torque density and performance as well as the comprehensive adaptation options of the high quality Heavy Duty HDO gearboxes, other factors were also essential for its use in the LPF. “The compact design of the HDO gearbox was the major benefit for its use in the LPF. Additionally, the friendly service and competent support from the Bonfiglioli team of engineers is always prompt and professional“, says Warren. Transmin is a major provider of innovative engineered equipment, supplies and services to the resources and bulk materials handling industries, including; mining and mineral processing. Their products are used in over 60 countries world-wide. “Therefore, in addition to the quality and competent service, Transmin also attaches great importance to fast and timely delivery, which also represents a great advantage when working with the long-established company from Italy.”“The reliability of Bonfiglioli’s drives is first-class. We’ve used their drives in numerous projects across Australia, including some in the harshest conditions, and their durability and reliability have always been outstanding,” concludes Warren.