Right-angled gearheads open doors

Edited by the Engineeringtalk editorial team May 18, 2007

ZF's SWG right-angled gearheads significantly reduced purchase costs and offered additional safety for Oculas 2.0.

ZF's SWG right-angled gearheads offer a smoother alternative to screwjack based door control systems used in the Oculas 2.0, designed by Lee McCormack and engineered by McLaren Applied Technologies.

The Oculas 2.0 is a multimedia product that provides the user with a completely immersive environment.

ZF supplied SWG gearheads to Mitsubishi Electric UK for the door operating system because of the choice of backlash options, which significantly reduced purchase costs and offered additional safety with anti-backdrive operation.

Everything about Lee McCormack's Oculas 2.0 needs to work as stylishly and efficiently as possible as it is designed for both the 'high net-worth' individual as well as business applications.

The futuristic pod provides the most advanced immersive branding, conferencing, purchasing, downloading, gaming, music, film, simulation and general entertainment experience available.

A single upward swinging gull-wing door is one of the main features of the Oculas 2.0 and its smooth operation is "essential in maintaining customer satisfaction" according to the designer.

The McLaren engineering team was responsible for bringing the project to fruition, but faced initial teething problems with the screwjack-based door control system.

"Opening and closing operations were functional, but when the 16kg door was lowered, the screwjacks caused a juddering motion that wasn't ideal, so Mitsubishi Electric UK were asked to specify a more effective solution", said McCormack.

The ideal door operating system would be based on a lightweight, high-ratio gearbox of the kind used in precision automation and packaging systems; however, these gearheads have traditionally been prohibitively costly for use in even luxury consumer applications".

"It was at this point in the design process that Mitsubishi Electric approached us with a view to specifying our SWG range of gearheads, which offer machine builders the choice of backlash levels of equal to or less than 10, 3 and 1 arc min" explains Dave Morgan, Technical Sales Engineer at ZF Great Britain.

"The SWG90 right-angled gearheads were specified with levels of backlash to equal to or less than 10 arc min, offering many of the operational benefits of a higher precision gearhead at approximately the third of the cost".

SWG80 units (90:1 ratio) provide the smoothest possible door motion.

Their precision high gearing offers the added bonus of eliminating backdrive, ensuring that in the event of power or system failure the door does not drop down, trapping or injuring the user.

The gearhead design performs well under high radial loads, a feature which has made the units popular with handling systems and machine designers and, ultimately, insures the immediate stopping of the door, despite the high moment of inertia caused by the offset door pivot.

SWG gearheads are designed for maximum mounting flexibility, as evidenced by the fact that the standard flanged model attaches directly to the Mitsubishi electric motor.

The hollow shaft and shrink disc option also allows easy fitting to the output, which in this case was the Oculas 2.0 door spindle.

In addition, sealed-for-life lubrication ensures a long maintenance-free operation and enables the gearboxes to be mounted at 45 degree angle in the main body of the pod.

The lightweight aluminium/magnesium body of the gearhead helps to reduce the final weight of the Oculas design and a computer-optimised worm wheel contact pattern offers quiet performance of less than 55dB.

The pattern achieves 90% contact during operation, distributing loads evenly and contributing towards the highly rigid performance.

Due to ZF's specifying two sets of oversized taper roller bearings in the SWG design, the gearwheel and spindle can also transmit higher loads with a greater degree of rigidity and accuracy.