Of course, there are alternatives to the conventional axle, some of which have been around for many years. Prominent among them are planetary gearbox based drives (combining gearbox and hydraulic motor), which provide a neater, more compact system with improved ground clearance for rough terrain and off-highway vehicles. Planetary gear designs deliver high-reduction ratios and are more compact than helical or bevel helical gearboxes.
Brevini Power Transmission has pioneered planetary gear drive technology since it began trading as far back as 1960 and has amassed a range of industrial gearboxes and compact wheel and track drive systems.
The Brevini planetary design incorporates multiple reduction stages within a compact envelope; the three planetary gears also share the radial load thus reducing wear and improving reliability.
The design also offers a large torque capacity due to an arrangement in which the input torque is shared between multiple sets of teeth on the primary drive pinion. Moreover, the planetary arrangement is highly efficient - up to 98 percent per stage – which makes it an attractive proposition for those seeking to improve the economies of running large, off-road vehicles.
Brevini wheel drives are now to be found in a wide range of vehicles, from agricultural machines and forklifts to heavy duty wheeled vehicles weighing up to 400 tonnes.
The company’s track drives too, are to found across many industries including mining and construction where tracked vehicles can weigh anything up to 130 tonnes. These ompact track drives are mounted inside the track sprocket and achieve very high reliability even in the most severe of operating conditions.
Both of these drive configurations for track or wheel offer a wide selection of reduction ratios, enabling the designers of mobile plant to match the drive unit with a suitable hydraulic transmission system. They also accommodate the mounting of all types of orbital, geared and axial piston type hydraulic motors supplied by Brevini Fluid Power.
Among the options available for these drives is a mechanical disconnect device, which is manually operated from the hub end-plate to enable safe towing in the event of an emergency. There is also 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 for mobile access equipment, which is sometimes manoeuvred with the platform fully raised.
Brevini claims to have a suitable drive for vehicles with anything up to 50 tonnes per wheel and up to 3m wheel diameter. And with the benefit of an experienced design team, the company is confident in its ability to assemble the correct drive package for every application.
Driving the fun on the Fireball ride
Brevini power transmission systems are not confined to huge off-road vehicles. Take the Fireball ride, for example. Located at The Adventure Island Park in Southend-on-Sea, Essex, this fairground attraction stands 9m tall and comprises a tower, which holds a rotating hub with eight arms, each having a double seat attached to the end of it. It was designed and constructed by the park’s own in-house engineering team, Adventure Island Workshop, which had the task of specifying an appropriate drive system .
Brevini suggested that its High Torque S-series reduction gearbox coupled to an electric motor would achieve the best fit within the main framework of the design. The gearbox and motor arrangement is mounted directly to the main frame of the ride using the motor foot plate and the drive end flange.
This design meant that the drive assembly had to provide the required power while being as compact as possible. The drive also had to meet the rigorous safety standards demanded by amusement park rides.
The S-series planetary design maximises performance from a smaller envelope. Indeed, Brevini claims that these gearboxes are able to offer between a 40-60 percent reduction in terms of size and weight against more traditional gearbox designs. These robust units have a torque range from 1kNm up to 2,500kNm, with larger capacities available on request.
S-series gearboxes can provide up to four reduction stages as standard, with both in-line and right-angle versions. Additional stages can easily be incorporated to achieve extremely high reduction ratios while maintaining a high overall efficiency.
Output shaft options include female splined, hollow cylindrical, male cylindrical and male splined versions. The gear unit input can also accommodate different motor types (electric, hydraulic) plus a multidisc brake, and there’s a wide range of input and output accessories to choose from.
Brevini’s gearboxes and gearmotor drives are to be found in other UK theme parks, not least, the famous Pleasure Beach in Blackpool where it has repaired and replaced various gearboxes in many of the UK’s most famous rides. In each case a specialist from Brevini is sent to inspect the gearbox and ascertain whether it should be repaired or more cost effectively replaced.
With regards to gearbox maintenance and replacements, Brevini is able to service gearboxes of any manufacturer, using OE parts to restore them back to their original specification, or it will engineer new gearbox configurations that fit within the original drive’s footprint, more often than not improving the performance and efficiency of the drive system into the bargain.