New generation bevel helical drives being introduced to Australia and New Zealand by Bonfiglioli Transmission have demonstrated their power, precision and performance in a demanding metal product manufacturing application.
The new HDP Parallel Shaft drives used in the manufacture of a wire drawing machine destined for India are part of a new generation of large industrial drives especially suited to demanding materials handling tasks.
The HDPs – complemented in Australasia by HDO Bevel Helical units in sizes up to 72,000 Nm – were selected by specialist manufacturer WWM, based in Padua Italy. WWM's main area of business is the production of drawing systems for welding wire, staple wire, bright wire and carbon steel wire.
WWM used a new HDP 70 parallel shaft gearbox to drive a monobloc wire drawing head in a machine capable of producing 7.5 metres of 4.2 mm diameter wire per second.
“This high capacity wire drawing machine is destined for installation in India, where one of Bonfiglioli's subsidiaries is on hand to provide continuous assistance to meet any servicing requirement,” says the managing director of Bonfiglioli Transmission, Malcolm Lewis.
“Power, precision and dependable performance were the key requirements of the HDP gearbox employed. The technical challenges Bonfiglioli had to meet for this particular application were associated with the continuous duty of the plant and a high drive input speed, factors which were further compounded by ambient temperatures of around 40 °C,” he said.
The first step of the project was to verify whether the gearbox was effectively compatible with the 34 kW - n=3000 min-1 vectorial motor involved, and that a minimum working life of 100,000 hours could be expected from the gearing.
The thermal characteristics of the gearbox were then examined and, for ultimate performance, a coil was installed in the gearbox sump to allow the circulation of cooling water at a temperature of 20 °C. In addition, it was agreed that the original B7 mounting position be changed to a B3 mounting to achieve an extra 20 kW of thermal capacity.
Viton compound seals were also fitted because of their special ability to withstand high operating temperatures.
“These modifications ensured that the gearbox could be used in complete safety,” said Malcolm Lewis. WWM chose Bonfiglioli Transmission's HDP unit for its superior performance (the Bonfiglioli unit is rated approx 10% higher than those of the competition) and compact dimensions, which greatly facilitated installation in the machine. Competitive pricing was also a determining factor in securing the contract.
“The new drives will be tailored to customer requirements through extensive assembly and service facilities in Australia and New Zealand,” says Malcolm Lewis.
“They feature good torque distribution across their entire ratio range, with gear ratios laid out in close progression and the drives having a rugged capacity to cope with the shock and impact of intermittent loads.
The HDO and HDP drives are the result of more than three years development to produce reliability and torque densities to record values, says Malcolm Lewis.
“Outstanding research and development has gone into producing these drives, with Finite Element Analysis and Multi Body Simulations conducted in order to identify the stress pattern on each of the main components and to optimize the design for:
- System structural stiffness
- Gear geometry
- Shaft deflection
- Extended gear and bearing lifetime
“Reliability is enhanced by a high radial load capacity, with 100% heavy duty bearings, and by reduced vibration and noise levels achieved by gears that are entirely ground-finished,” said Malcolm Lewis.
Units up to size 120 (35,000 Nm) feature rigid monoblock housings, while larger units feature a horizontally split housing.
Input shafts are supported by robust taper roller bearings. They may be coplanar, sitting 90 degrees apart, for optional mounting positions, or allow both a main and pony drive to be fitted.
Latest generation heavy duty roller bearings are used to withstand the forces generated internally and applied externally. Accurate proportioning of the shafts allows for lifetime balance of each axis.
The drives’ versatility in service is enhanced by numerous mounting options suitable to their typical applications, such as materials handling (inc belt, apron, bucket, screw and chain conveyors), manufacturing, mining, quarrying and minerals processing, rural and food product processing, paper, pumps, steel, sugar, timber, wrapping and stacking applications, and water and waste water treatment. The drives’ multi machined surfaces and symmetrical design allows them to be used in either left or right hand configuration.