Energy and signal supply system in gantry loaders: high speeds, quiet operation

Today, the Gehring Group is one of the global market leaders in precision machining. The plant manufacturer designs special horizontal machines for holes up to 15 metres and transfer lines for the production of engine blocks. These machines not only perform honing, but also other work steps such as scooping out cooling lubricant residues and cleaning. All with a high throughput: With cycle times of almost always less than one minute, high availability requirements must be met in 24/7 operation.
As users today want the greatest possible flexibility, the transfer lines in particular have changed. The motors are getting smaller, the product life cycles shorter. Individual machine modules that have to be connected via gantry loaders are being built as a priority.
Gehring expanded its business area in 2014 to also offer such gantry loaders. Today, the plant manufacturer offers a modular system for gantries that enables the combination of different slides, vertical axes, loading systems and grippers.
However, the energy supply of these gantries posed a major challenge: a modular machine for honing the crankshaft bore can be up to 8 metres long. The cylinder modules take up 2.60 metres and, for reasons of accessibility, a space of 3 metres is required between each one. This means that the gantries manufactured to date - and therefore the travel paths of the energy chain - are 20 to 33 metres long. The load is also impressive: in a current project, the gantry is travelling at 3 m/s and an acceleration of 7 m/s2. However, gantries have also been built for 10 m/s, which are used in a crash test rig.

When choosing the energy supply system for the gantries, the Gehring designers opted for our energy chain including guide trough and chainflex® cable. Supplied as readychain® systems, the e-chain® is already assembled ready for installation. This means that Gehring passed on the necessary design data to us, we designed the e-chain®, manufactured, assembled and customised it and finally delivered it ready for installation together with the cable.
As the demanding combination of long travel, high travel speeds and long service life (ten years is required) cannot be achieved with a sliding chain, we specifically recommended that Gehring use the P4 series profile roller chain. Here, the rollers of the upper and lower run do not run on top of each other, but offset on a continuous, wide rolling surface. This enables smooth, even running even on long distances of up to 800 metres of travel.
The autoglide crossbar ensures safe guidance, while at the same time significantly reducing the drive power required and increasing service life. A
chain from the E4.1 programmeis used for the energy supply from the gantry, i.e. the X-axis, to the loaders (Z-axis). Here, the rear grip in particular ensures significant lateral stability compared to conventional systems.
Finally, our chainflex® cables are also used for moving applications. Gehring uses the CF27 servo cable series for the fast X-axis, which is characterised by an additional pressure-extruded TPE inner jacket, among other things. We give a guarantee of 10 million cycles or 36 months on these cables. Cables from the CF113 series are used for data transmission, with an expected service life of 20 million
cycles in this specific case. The energy supply contributes to the high availability of the gantry - in three-shift operation at 160 strokes per hour.