Low-wear roller energy chains for loading gantries in the automotive industry

Profile

• What was needed: profile roller energy chain P4.32 with autoglide system and aluminium guide troughs, supplied as a pre-assembled readychain system
• Requirements: high dynamics at travel speeds of 6m/s and accelerations of 6m/s²; wear resistance; high availability; noise minimisation
• Industry: automotive industry, machine tools
• Success for the customer: the roller energy chains easily cope with the high dynamics of the system in continuous operation; the roller system is wear-resistant, reliable, smooth-running and requires 57% less drive power than gliding chains; the pre-assembled readychain system minimises installation time and costs

A linear gantry is being set up in the production area. The roller energy supply withstands the high acceleration and speed on a permanent basis. There is no need to compromise on machine availability.

Problem

The product range of GROB-Werke GmbH & Co. KG includes flexible manufacturing systems for the automotive industry. This includes machining centres, special machines and their automation.
The company has developed a new linear gantry, also called a translator, which was presented with great success at EMO.
The new linear gantry or translator is much more compact and smaller than the company's previous solutions. The height of the X-beam above the hall floor is now just under 3.20 m.
A new development is the vertical suspension of the skate wheel, which carries a load 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. The gripper can be supplemented by a pivot axis in the A or C direction. By reducing the moving masses, significantly higher travel speeds and acceleration values are achieved. With a travel length of up to 40m, the speed is 6 m/s, the acceleration 6 m/s². Speed and acceleration were twice as fast as in the previous model. The dynamics of the linear gantry, which have been significantly improved in this way, enable the loading of linked single and double spindle machines with a single gripper.
A complete production line consists of the linear gantry on the one hand, and single and two-spindle machining centres for the workpieces on the other.
Due to the high dynamics of the gantry, questions quickly arose for those responsible regarding the appropriate energy supply. In addition to other requirements such as high wear resistance and long service life, it was necessary for reasons of occupational safety that the sum of all noises is relatively low at the same time.

Solution

During the tests in the preliminary stages, magnetic chains and plastic energy chains were pitted against each other. The decision was clear: internal investigations showed, amongst other things, that magnetic chains neither meet the requirements for quiet operation nor permanently withstand the high speeds. The linear gantries usually run six days a week in three-shift operation; machine or system downtime must not occur. Low-maintenance roller energy supply systems of the P4 system are therefore used in the linear gantry. The special design of the rollers and chain links enables particularly quiet operation. The chain is also suitable for high travel speeds, long travels and high fill weights. The staggered rolling of the upper and lower runs further increases the service life of the chain. It is also particularly abrasion-resistant. The rol e-chain achieves exceptionally quiet and vibration-free operation. Cable-friendly 'Auto-Glide' crossbars made of tribologically optimised polymer and aluminium troughs from the modular system guide the energy chain safely. In addition, there is a silencer profile in the trough that further minimises noise generation.
Compared to sliding friction, rolling friction is basically 75 % lower. The resulting reduction of up to 57 % in drive power means more energy-efficient work processes.
The energy supply system was supplied as a pre-assembled ready-to-connect readychain system and can be easily installed via "plug and play".
But polymer energy supply systems are also used in the horizontal slide changer in the linear gantry, which replaces the pivot changer during loading and unloading. They ensure the necessary machine and system availability that GROB-Werke guarantees its customers all over the world.

Robust energy supply systems are also used on the pivot arm, another new development

Another application for a small energy supply system. Here in the new pivoting gripper.

The system presented at EMO is being put through its paces on site in Mindelheim under realistic production conditions.

The newly developed loading gantry is characterised by very high accelerations and speeds as well as very high positioning accuracy and is suitable for loading workpieces of medium masses.