Ovoid gearbox design gives four times the torque

Rotalink has combined spur and planetary gear stages within industry standard ovoid gearboxes for a four fold increase in output torque.

The gearboxes are the result of an ongoing design effort at the Crewkerne based firm to use advanced ultra polymer materials technology to obtain a much higher power-to-weight ratio. This allowed the gearboxes themselves to be made smaller and also provided quieter operation. Spur gears run on fixed steel spindles leading to the final planetary output stage with precision ball bearings supporting the stainless steel output shaft which is available as a standard flatted design or can be customised for the application. As a result of the development, the company has launched three gearbox lines to enable either higher torque or reduced gearbox size. • The 330 series - a form-fit mounting replacement for the conventional 'standard' industrial ovoid gearbox – has a vastly improved 13Nm peak holding torque. • The 360 series - a slightly larger model has 28Nm peak torque in a gearbox case that measures 95mm x 60mm x 31.5mm. • The 310 series - the smallest ovoid gearbox design that mounts within a volume of just 45mm x 29mm x 20mm but boasts a 2.6Nm holding torque for a 10,000 hour life. The 310 series offers all spur gear versions and different levels of advanced gear materials, with a choice of plain or ball bearings. These options de-rate the maximum torque and performance capability but offer a more cost effective solution for less demanding applications. The 330 and 360 series are also available with different levels of gear materials and a choice of bearings. A wide range of ratios are available, typically from 24:1 to 3200:1 depending upon the model size, with maximum output speeds between 300 to 400rpm. All include a zinc plated pressed steel gearbox case and cover with 4-point mounting for maximum durability. All gearboxes are designed for fast and straightforward interfacing with Rotalink's comprehensive range of DC, AC and stepping motors along with single and dual channel feedback encoders which are fitted directly between the motor and gearbox assemblies. This allows the use of, off-the-shelf single output shaft motors which helps to reduce product costs and development timescales.