Rösrath, 21/10/2016 - “Downsizing” is a keyword often associated with engine technology. However, all vehicle components must be optimised for weight and functionality if fuel consumption and emissions are to be reduced effectively and sustainably, while at the same time maintaining or increasing performance. Driveline specialist GKN has achieved precisely this objective with its completely new concept for hub connections.
Known as the Face Spline design, this forms a permanent fit between the wheel hub and the fixed driveshaft joint via a spline on the joint’s face. It is known as “Face Spline” because torque is transferred from to the hub via the joint’s face. The design is considerably less complex compared with existing shaft connections, which saves weight (see image). Combining this with GKN ST technology (Driveshaft Twin Ball with s-shaped ball track) improves efficiency even further. An additional benefit is obtained from reduced internal friction in the joint.
This hub connection is ideally suited to the high-torque turbo and electric drives of the future. Additionally, the weight saving directly at the hub aids not only downsizing, but also reduces unsprung mass. In the case of GKN Face Spline design, this amounts to approx. 20%, which leads to a noticeable improvement in ride and handling. Furthermore, the assembly process is simplified considerably by front fastening, ball centring and the absence of play in the connection between half shaft and wheel hub.
These benefits have convinced vehicle manufacturers such as BMW to select GKN’s Face Spline technology for new vehicle models with X-Drive.
“GKN Land Systems offers a Face Spline range for all BMW models equipped with this technology ex-works,” says Frank Hürter, Commercial Director Automotive Aftermarket, “this technology is provided without any trade-offs in ether design or quality. This enables independent workshops to maintain the very latest vehicles, while benefitting from easier and more reliable installation.”
|Figure 1, UF-Face Spline, cut-away model|
The Face Spline design forms a permanent fit between the wheel hub and the fixed sideshaft joint via a spline on the face of the joint. It is centred via a cone in the hub and force-fitted to the hub by an anti-fatigue bolt.
|Figure 2, Traditional Stem Design|
Comparison with the conventional pin design. Its greater complexity means more weight.