Precision bearings and automotive engine components manufacturer The Schaeffler Group has developed a groundbreaking new slim design of spur gear differential for passenger cars, which is not only 30 per cent lighter than its predecessors, but will also create up to 70 per cent free axial space in the gearbox.
Furthermore, the slim shape of the new differential enables the use of new bearing concepts with optimised friction characteristics, which in turn will have a positive effect on fuel economy and CO2 emissions. Ultimately, the lightweight differential will save space that can be used for larger dual clutches or transfer gearboxes, as well as making room for electrical components on hybrid electric vehicles.
Thorsten Biermann, Project Manager Advance Development Automotive Transmissions at The Schaeffler Group comments: "Spur gear differentials offer enormous advantages. Compared with the original bevel spur gear differential, our new differential saves up to 30 per cent in weight and creates up to 70 per cent free axial space because of its slim design. In absolute terms, this means up to three kilogrammes mass reduction for each differential and up to 90mm of extra space in the gearbox."
In the 1950s, a mid-sized car weighed in at around 900kg. 50 years later, this figure had increased to around 1,600kg. This steep rise was due to a host of new safety and comfort features which were partly driven by consumer demand. Numerous electronic aids were also responsible for the additional vehicle weight, which actually runs counter to the manufacturer's demand for lower fuel consumption and emissions.
Every kilogramme that can be saved from the overall weight of a vehicle is therefore critical, putting increasing pressure on vehicle manufacturers and their suppliers to minimise the size and weight of powertrain systems and engine components.
The design of the new lightweight differential was inspired by another project at Schaeffler. The Group's Automotive Advance Development Division came up with the new idea after working on a planetary stage design for an automatic transmission manufactured for a metal forming process application. This inspired the team to come up with a differential in a planetary design for a typical mid-size passenger car.
The lightweight differential has already been installed in a mid-size passenger car. The two-and-a-half year advance development project has already slipped seamlessly into a variety of customer projects. Tests are currently being carried out on the differential, including some on gearbox test rigs. These will be followed by an intensive design optimisation stage, after which Schaeffler will decide whether to move into series production of the lightweight differential.
As Dr Thomas Smetana, Senior Manager Advance Development at The Schaeffler Group concludes: "This development is a very special achievement - a lightweight differential that saves not only weight and space, but which also reduces friction in the main bearing support."
For more information on Schaeffler's range of automotive bearings and other engine components, please visit www.schaeffler.co.uk or telephone the marketing department on 0121 313 5870.
The Schaeffler Group is among the innovation leaders in Germany with around 1,250 patent applications annually. With its brands INA, LuK and FAG, it is a renowned supplier to the automotive industry as well as a leading manufacturer of rolling bearings worldwide. Around 65,000 employees generated sales of approximately 7.3 billion euros in 2009. The automotive industry represents around 60 per cent of Schaeffler sales.
The Schaeffler Group is a renowned development partner to the industry with system expertise for the entire drive train. Precision products for engines, transmissions and chassis applications ensure reduced energy consumption and lower emissions as well as increased driving comfort and safety. In addition to classic manual transmissions and automatic transmissions, the Transmission Systems Business Division offers automated manual transmissions, dual-clutch transmissions and CVTs. The range of transmissions for the future is rounded off by applications for alternative drive concepts such as hybrid drives. Schaeffler Automotive Aftermarket supplies distributors and independent workshops with replacement parts and services.
Schaeffler (UK) Ltd,
West Midlands B76 1AP
Tel: 0121 313 5870
Fax: 0121 351 7686