New Fenner Series K Gearboxes Offer High Performance

Fenner Series K gearboxes employ a highly efficient helical reduction input stage in front of the main bevel helical gear, which in combination with high quality low-friction bearings and precision manufacture delivers efficiency levels as high as 97% across the range. The resultant energy savings can be substantial when compared to traditional worm and wheel driven gearboxes that are usually only around 70% efficient and can be as low as 65%.

Fenner gearbox product specialist John Woodcock explains the difference, in traditional right angle worm gear reducers, a hard steel worm gear is used to drive a softer wheel, usually Phosphor Bronze, the softer material is slightly sacrificial, and the sliding action of the gears as they mesh generates friction and heat, to overcome this up to 30% of the power input into the gearbox is consumed, and the unit will tend to wear faster.

Bevel helical units such as the new Series K on the other hand use a more complex bevel gear profile and matched gear materials, the result is a smoother drive with less friction and greatly reduced wear characteristics. They are also quieter in operation and offer significantly higher torque capacity based size for size.

Bevel helical units are more expensive to produce and require more advanced machining techniques, the price difference used to be significant when compared to worm and wheel units, but the cost of producing good quality bevel helical units in the UK has been reduced due to improved production efficiency and resulted in far more competitive pricing.

The other contributing factor to the increased take-up of bevel helical units in the UK is the increased cost of energy and downtime; running costs have increased to the point where the initial purchase cost is dissipated within a few months by the energy savings and a bevel helical unit will outlast a worm unit, reducing maintenance costs and disruption as well as maintaining low backlash characteristics and high precision throughout it operating life.

Example A WYKO customer was supplied with a trial Series K unit as a replacement for a 12?Worm box with 50:1 ratio, running for 3500 hours per year (about 10 hours per day). The original unit absorbed an average of 30 kW of power, consuming 140000 kWh during the year, at ?.06 per kWh the total running cost was ?,400 per annum. The Bevel Helical Series K used only 108250 kWh in the same application, costing just ,495 a year to run, delivering a saving of ?,905 and a short ROI period.

John Woodcock adds, there has been some resistance towards fitting replacement bevel helical units from Plant Managers in the UK, but recent increases in energy costs have resulted in Plant Engineers and Managers alike being more responsible for reducing costs and increasing efficiency, this has changed attitudes towards bevel helical units and we have found they are far more acceptable. They represent better technology and we have lagged behind Europe to some extent in introducing them, but it is the right time for us to launch the Series K and initial demand is strong.

Series K gearboxes are available in foot, face or flange mounted configurations across the range, and are also designed to be used as a shaft mounted unit with output shafts as options. Smaller sizes up to 11kw are expected to be shaft mounted, while larger units are more likely to be foot mounted and so will often require an output shaft and coupling, both of which can be supplied with the gearbox. Fenner Series K gearboxes are stocked and assembled in the UK hence lead times are short.

Fenner products are available from both at Independent stockists and at any one of the 170 WYKO branches located throughout the UK.