GKN “Face Spline”: the downsizing does stop at the driveshaft

GKN patented „Face Spline“ technology provides a lighter weight to the joints of the hub, but a greater power transfer efficiency.

Rösrath, 21st of October, 2016 – Keyword “downsizing” is usually associated with an engine technology. However, other components of the vehicles should be optimised towards lighter weight and greater functionality, if the fuel consumption and emission are decreased efficiently and in a sustainable manner. At the same time it is necessary to maintain or to even increase the efficiency. This was the objective that GKN, a specialist in transmission, reached with a completely new solution for hub joints.

The so called “Face Spline” structure forms a permanent fit between the wheel hub and the fixed driveshaft joint.
It is known as “Face Spline” since the torque to the wheel hub is transmitted through the serrated surfaces of the hinge and the hub. The weight-saving design is considerably less complex compared to the existing shaft connections and at the same time the weight has been decreased (compare pic. 1 and 2). “Face Spline” is combined with another GKN technology ST – “Twin Ball” side shaft with s-shaped ball tracks. This way the efficiency increases even more. Additional benefits are gained through the reduced internal friction of the lever.

A face-spline hub connection is ideally suited for high-torque turbo and electric drives of the future. Weight savings directly at the hub not only aids in downsizing, but also reduces unsprung mass. In case of this GKN “Face Spline” structure, a decrease of the unsprung mass of 20% is reached, which leads to a noticeable improvement in ride and handling. The assembly process also is simplified considerably by front fastening, ball centering and the absence of looseness in the connection between half shaft and wheel hub.

The said benefits have convinced such vehicle manufacturers as, for example, BMW, which chose the GKN “Face Spline” technology for the new car models with an X-Drive transmission.

“GKN Land Systems” offers the market a range of “Face Spline” technology parts to all BMW models, to which they are factory installed”, says Frank Hürter, the Commercial Director of Automotive Aftermarket. – “This technology is supplied to the market in its original form, with no changes to the structural quality or compromise. This allows the independent car repair shops to service the newest and most modern cars, which benefits them due to the noncomplex and reliable installation.”

About GKN
GKN is the world’s leading supplier of components and systems for transmission. Its pre-eminent market position is based on many years of technological experience. “GKN Service International” supplies original GKN parts to the secondary market as well. GKN offers a highly comprehensive range of car side shafts, prop shafts, joint kits, boot kits and other vehicle parts under the brand names Spidan and Löbro through wholesalers and local parts dealers. For more information, visit: www.gknservice.com

1 pav. “Undercut Free” ir “Face Spline” joint structure technologies
The “Face Spline” design forms a permanent fit between the wheel hub and the fixed driveshaft thanks to the “Undercut Free” serrated surfaces at the joint area. The structure is centred through the conical surfaces of the hinge and hub and firmly tightened with an anti-fatigue bolt.

2 pav. Structure of the traditional system
A traditional drive shaft joint structure with a bolt is presented for comparison. Its greater complexity means a greater weight.

Example of a BMW “Face Spline” drive shaft: