For years, the focus of car designers has been the steering gear. The system has been complemented by complex secondary drive systems. Drivers are now clamouring for steering systems with even more precision. In order to meet this demand, the production of associated components also changes – it has to become more efficient and more precise.
This is especially true for the most demanding components, such as the ball screw nut. It requires a particular grinding method that creates a perfect connection between the ball screw spindle and the ball screw nut to guarantee greater efficiency.
Innovative Processing Speeds Reduce Idle Times
How the production technology changes under these conditions is demonstrated by an innovative new machine from EMAG: the VLC 250 PDS. It was specially developed at the request of a customer who wanted to grind their ball screw nuts. Of course, the machine can also be succesfully used for many other two-stage grinding processes. Its innovative processing speeds – achieved with two pick-up spindles on the same axis – ensure extremely short idle times. While one pick-up spindle removes a component from its particular infeed system at one side and conveys it to the measuring probe, the second pick-up spindle is already in the machining area, conveying the ball screw nut to the two grinding spindles (where the two-stage grinding process is carried out).
Correct positioning is imperative
What‘s the advantage of this approach? The answer relates to the correct positioning of the workpiece in the machine: before the grinding process can begin, the component’s inner contour has to be aligned to ensure the grinding spindle can be positioned at the end of the thread – a pretty time consuming process. In order to achieve this, EMAG relies on its perfectly timed system, while the measuring or positioning of one workpiece is completed simultanously with the machining of another. This reduces unproductive idle times.
Keeping an Eye on new Components
“Pendulum grinding“ is what the engineers call this revolutionary and high-performance approach that relies on the machine details. For example, the two pick-up spindles are mounted on particularly sturdy compound slides; while the powerful linear motor in X-axis generates high acceleration values. And the necessary workpiece quality is achieved by the machining in one set-up – a standard benefit of EMAG machines. It is obvious that this design could, in the future, be used for many other applications that call for a two-stage grinding process. Of course, many production processes would benefit from the innovative processing times one can achieve with two pick-up spindles. Over the next few years EMAG intends to promote the advantages in the market vigorously.