Fig. 1: Hydraulically activated clamping element, two-piece version, with tungsten carbide coating

Fig. 2: CAD model of a rotary table application, where the clamping was carried out with a one-piece hydraulically activated clamping element.

Hydraulically activated clamping elements for milling head clamps as well as revolving and rotary table clamps

Automated clamping and releasing based on the Spieth principle

Hydraulic clamping elements are often expensive with complex assemblies and time-consuming installation. At the same time, these systems offer little radial rigidity. Engineers at Spieth have used the tried-and-tested Spieth clamping set technology to develop a hydraulic clamping element that enables automatic clamping and release with a reduced number of components, a high degree of radial rigidity and the utmost precision. This solution implemented in close cooperation with well-known customers is inexpensive and is also characterised by simple assembly and dismantling as well as a high degree of reliability.

The innovative solution automates the clamping process by means of hydraulic pressure, which is a considerable advantage compared to standard applications which require the use of screws or activation through an external actuation. The system enables fast clamping and releasing in a wide variety of applications. In contrast to conentional hydraulic clamping sets, this solution provides a high degree of radial rigidity and a direct power flow between the shaft and hub thanks to the proven Spieth principle.

Hydraulically activated clamping elements by Spieth are individually designed with the respective application requirements in mind. These precision elements are available in one or two-piece versions and provide their clamping effect when hydraulic pressure is applied, with no additional peripheral being required. As such, the advantages of the proven Spieth principle with its unparalleled concentricity and user-friendly assembly are enhanced by the option of automating quick clamping and release processes.

Innovative milling head clamps – high performance in the smallest of spaces

A leading manufacturer of 5-axis milling machines in travelling column design adopted this pioneering solution early on: the system has been used successfully for many years and is therefore an ideal alternative to complex hydraulic systems.

Apart from the hydraulics already present, no other periphery is required to use the hydraulically activated clamping elements. Components can even be saved compared to alternative solutions. This reduces the workload and costs, whilst minimising the complexity of the assembly. In combination with the low wall thickness, a compact and efficient solution can be implemented in the smallest of spaces.

The positioning accuracy of the milling head will not leave you disappointed: thanks to the inherently rotationally symmetrical design and the very uniform transmission of force, the Spieth elements enable position-neutral clamping behaviour without axial thrust. Combined with the elastic properties of Spieth technology, simultaneous clamping and release of all contact points and thus continuous clamping with the utmost precision is guaranteed at all times.

The customer’s designers used Spieth products to achieve a high degree of radial rigidity of the assembly. The clamp reacts extremely quickly as a result of the elasticity of the innovative Spieth principle: there is no contact of the contact partners between clamping and restarting, which eliminates waiting times until a new rotational movement can be made. All in all, the milling head has a high material removal volume and maximum productivity thanks to these properties.

Contact corrosion occurs in many applications with frequent clamping operations over long periods of time. Whilst the contact partners are generally spared thanks to the Spieth principle, the engineers at Spieth have additionally provided the hydraulically activated clamping elements with a tungsten carbide coating in their innovative solution in close cooperation with customers. This is available as an option from Spieth. It offers an ideal balance between excellent sliding properties and reliable clamping without slipping or slackening and ultimately enables extremely long maintenance intervals.

This is exactly what’s paid off for the customer in cooperation with Spieth: more than 1 million clamping operations have been demonstrably achieved in the testing laboratory. The solution developed together with the Spieth engineers has also been tried and tested in practice: customers consistently rely on the durability and reliability of the milling head, which is clamped with hydraulically activated clamping elements.

Inexpensive and precise solution for revolving, swivel and rotary table clamping

Spieth is also quickly making an impression with new customers with the hydraulic clamping elements for applications in rotating and swivel tables as well as rotary tables. It goes without saying that the positioning accuracy also plays an extremely important role in these applications. This is achieved with the rotationally symmetrical design, the position-neutral clamping behaviour of the Spieth elements. The Spieth principle entails a direct power flow between the shaft and hub. In combination with the high transmittable torques, this enables complete flexibility, particularly with changes of direction, and thus a high level of motion accuracy.

Short switching times and thus high dynamics can also be achieved with the precision elements from Spieth. When activated, the elastic elements react extremely quickly, with all contact points being simultaneously clamped or released.

With their decision to use hydraulically activated clamping elements, the designers of a global market leader in the field of rotary table applications achieved high holding forces in a very small amount of space. Numerous connection parts are also superfluous in this example thanks to the solution which is individually tailored to the customer’s needs.

One of the central requirements for the rotary table clamp in the course of the customer project is ensuring a high degree of torsional rigidity. Here too, the properties of the Spieth products are a real asset for the designers: in the one-piece version, the components inherently have a very high moment of resistance against torsion and enable reliable and long-lasting clamping thanks to the purely mechanical effect.

The customer ultimately received a customised and inexpensive solution boasting excellent energy efficiency, which guarantees maximum reliability and productivity with ultimate precision and little complexity without the need for complex regulating mechanisms. “Developing innovative solutions based on tried-and-tested technology is the way to provide crucial productivity benefits for our customers quickly and reliably,” according to Spieth Managing Director Alexander Hund.

The development of the hydraulic clamping elements is once again testament to Spieth’s groundbreaking technical expertise. “We see ourselves as our customers’ solution partner. With our hydraulically activated clamping elements, we therefore also take responsibility for calculating the necessary parameters, such as hydraulic pressure based on the application,” says Heiko Alxneit, Head of Product Management at Speith.

Overview of the advantages of the milling head clamp