Wheel drive gearboxes for self-propelled vehicle

Edited by the Engineeringtalk editorial team Jan 19, 2001

A new 12 tonne, self-propelled vehicle is benefiting from the high power, reduced weight and extremely compact dimensions of Brevini's CWD wheel drive gearboxes

A new 12 tonne, self-propelled vehicle for turning through compost windrows and aerating solid waste on municipal tips is benefiting from the high power, reduced weight and extremely compact dimensions of Brevini's CWD wheel drive gearboxes.

The gearboxes mount inside the wheel rims of the vehicle, enabling the manufacturer, Traymaster Ltd, to reduce the number of parts in the transmission with consequent savings in cost, weight and build times.

Traymaster Ltd, based in Great Yarmouth, are innovators and leaders in the development of materials handling systems, designing, manufacturing, installing and servicing their own product range.

Recently, the company diversified its activities into waste management with its self propelled Windrow Compost and Soil Turner.

More commonly known as a "Windrow Turner", this unique unit has a homogenous mixing and chopping action that accelerates composting processes, reduces odours and generally increases throughput on waste sites.

"The Windrow Turner operates under a most arduous set of conditions", says Traymaster's Steve Thouless.

"The environment is always dirty or dusty, often wet and on waste sites, littered with all manner of rough objects.

Yet despite the conditions we have never had a failure of one of the Brevini wheel drive units, they have always been totally reliable".

"The ability to mount an integrated unit with its own packaged hydraulic motor inside the wheel of the Windrow Turner is a big advantage for us.

Previously we employed shaft or chain driven systems but these involved more components and took longer to assemble.

More parts mean more maintenance of course, something both ourselves and the operators of our vehicles wish to avoid.

With the Brevini units we have fewer parts so assembly is quicker and maintenance is reduced and easier to carry out.

The wheel drives are extremely compact, yet despite their size they provide high levels of efficiency and reliability".

The advantages provided by the Brevini units means that Traymaster is increasingly employing them on other types of mobile equipment, which it manufactures (see http://www.traymaster.co.uk).

This success is also being repeated with other manufacturers of mobile plant who are finding that the wheel drives permit a much neater design solution than axle drives, and provide greater clearance for rough terrain vehicles.

The highly efficient combination of a Brevini planetary gear unit and high-speed hydraulic motor is more economical than using large slow-speed hydraulic motors, alone, and offers significant operating advantages: - In the event of hydraulic fluid contamination only the inexpensive package motor need be replaced, and this can be removed and refitted in minutes.

- The gearbox / motor combination is capable of the very low speeds required when, for example, inching vehicles into position.

An added advantage of the CWD wheel drive units is that they incorporate a mechanical disconnect device.

This is manually operated from the hub end-plate and enables a vehicle to be towed in an emergency.

Also, as an option, the CWD units can be fitted with an integral multi-disc negative parking brake, which is spring applied and hydraulically released.

This functions as an emergency fail-to-safe brake should the hydraulic pressure fail and is an important safeguard on such equipment as access vehicles, since they are sometimes manoeuvred with the platform fully raised.