Quiet, fast and efficient

Profile

• What was needed: Profile roller energy chain P4.32, supplied as a pre-assembled readychain® system
• Requirements: high demands on dynamics, wear resistance and service life due to high travelling speeds and accelerations and use six days a week in three-shift operation; low noise levels were required
• Industry: Mechanical engineering, automotive industry
• Success for the customer: Extremely long service life (approx. three to four times longer downtime than sliding chains); energy efficiency: drive power reduced by up to 57%; energy chain is perfectly designed for high travel speeds, long travel distances and high fill weights; smooth and vibration-free running and a silencer profile in the trough significantly reduce noise levels

Problem
The product range of GROB-Werke GmbH & Co. KG includes flexible manufacturing systems for the automotive industry. These include machining centres and special machines as well as their automation. The aim of the machine manufacturer is to be able to machine workpieces faster and more cost-effectively, while at the same time optimising workpiece quality and machine service life.
This also applied to a new linear gantry, also known as a translator. The gantry system is much more compact and smaller than the company's previous solutions. The height of the X-beam above the hall floor is just under 3.20 metres. Another new development is the vertical suspension of the trolley, which can carry loads of up to 80 kg, and the loading arm on large skate wheels below the X-beam. The already proven technology of the loading arm in parallel kinematics has also been further improved. In future, the gripper can be supplemented by a swivelling axis in the A or C direction. By reducing the moving masses, significantly higher travelling speeds and acceleration values can be achieved. With a travelling length of up to 40 m, the speed is 6 m/s and the acceleration 6 m/s2, double that of the previous model. As a rule, the system delivers these maximum outputs six days a week in three-shift operation.
All these developments in the machine concept ultimately also raised questions about the appropriate energy supply system. The machine specialist places high demands in terms of dynamics, wear resistance and service life. Finally, the sum of all noises had to be relatively low for health and safety reasons.

Solution
In the preliminary tests, magnetic chains and plastic energy chains were pitted against each other. The decision was clear: internal investigations showed, among other things, that magnetic chains neither meet the requirements for smooth running nor can they withstand the high speeds in the long term.
Today, the profile roller energy chain P4.32 from igus® has proven itself in the new translator. One of its main features is that the upper and lower run roll offset to each other. As a result, the plastic profile rollers do not run on top of each other, but instead run past each other in an offset manner on a continuous wide surface. This increases the service life of the chain, which can be expected to have three to four times the downtime of sliding chains. Energy efficiency also increases: compared to sliding friction, rolling friction is generally 75 % lower. This means up to 57 % less drive power. Furthermore, the chain is particularly suitable for high travel speeds, long travel distances and high fill weights. The energy chain also achieves particularly smooth and vibration-free running in the radius. Cable-friendly 'Auto-Glide' crossbars made from tribologically optimised plastic and aluminium channels from the modular system guide the energy chain safely. There is also a silencer profile in the trough, which further minimises noise development. Peter Vogl, Director of Design & Development at GROB-Werke GmbH & Co. KG in Mindelheim, can only confirm this: "In our internal measurements, the total operating noise of the systems is 72 dBA, which is well below the maximum 75 dBA permitted by some customers." The energy supply system is supplied as a pre-assembled, ready-to-connect readychain® system that can be easily installed via 'plug and play'. The system manufacturer has been relying on pre-assembled system solutions for many years, especially in the gantry sector.