The right system for vertical energy supply with high dynamics

"Fast" energy supply for high-performance SRMs

Winkel has realised an innovative drive concept in the new Colibri series of storage and retrieval machines, which allows previously unattained dynamics and offers even more advantages. The vertical supply of energy and signals to the load handling device is also adapted to the high dynamics. The energy chain system guidelok slimline F from igus® is used here, which was developed for speeds of up to 7 m/s and accelerations of up to 10 m/s2 and is also very light and compact.

When it comes to linear guide and drive systems, Winkel GmbH has a good reputation throughout the material handling industry. The company began developing WINKEL guide systems for heavy loads more than 30 years ago. The WINKEL ROLLE with the appropriate guide profile is mainly used in the lift masts of industrial trucks and stationary conveyor technology systems. Based on this modular system, Winkel GmbH develops and produces complete machines for lifting and conveyor technology, which are used by major system manufacturers and general contractors as stroke and handling systems, robot linear axes, multi-axis linear systems or storage and retrieval units.

In this business field, Winkel GmbH has primarily realised customer and application-specific special systems over many years. Recently, the company introduced another series product in this demanding field of conveyor technology: the "COLIBRI" storage and retrieval unit, which is characterised by particularly high travel dynamics. Dipl.-Ing. Thomas Riffert, CEO of Winkel GmbH: "We have found that many of our customers have similar requirements: a very dynamic storage and retrieval unit that moves with high precision and enables maximum space utilisation."

New drive concept enables impressive dynamics

The dynamics of the COLIBRI-RBG are indeed impressive and can be followed "live" in the Winkel GmbH test field. The device travels horizontally at a maximum speed of 6 m/s and an acceleration and deceleration of 5 m/s2 - at all heights. When lifting, a speed of 3 m/s and an acceleration of 3 m/s2 are achieved. This is made possible by an innovative positive-locking drive concept: a frequency-controlled central drive on the lower and upper rails each engages with a gear in a gear rack; synchronisation takes place mechanically via a cardan shaft. Thanks to its rigidity, this type of drive ensures highly dynamic operation without load oscillation - and there is no need for complex electronic synchronisation of the two electric motors or an anti-oscillation system, which is almost impossible to implement at such high speeds.

High level of safety in a compact installation space
This special drive design also has a favourable effect on the safety and installation size of the automatic storage and retrieval machine. A TÜV-tested safety brake system ensures that the hydraulic buffers, which normally serve as end stops at the end of the aisle, can be omitted. This saves additional space that customers can fill with goods.

Lightweight construction brings advantages - also for the RBG
Another advantage of the new drive is its low weight. Thomas Riffert: "The synchronised drive creates the conditions for a 30% lighter mechanical design, so that we can use a smaller drive and thus work energy-efficiently despite the very high dynamics."

The challenge of energy supply
One of the challenges that the engineers at Winkel GmbH had to solve during the development of the "COLIBRI" was the vertical energy supply to the load handling device. Due to the long-standing relationship with igus®, an energy chain with guidelokguidance was initially used. This guidance system was specially developed by igus® for SRMs and other conveyor applications. It dispenses with the usual closed channels or other enclosures. Instead, the chain is fixed in the trough by two rocker levers actuated by the radius.

guidelok has proven itself in numerous applications, but reached its limits here due to the very high travelling speeds. So it was a good thing that igus® presented a new guide system almost at the same time as the first "COLIBRI" was completed at Winkel GmbH.

Easy to install, securely guided
The system with the designation guidelok slimline F (the "F" stands for "fast") is characterised by optimised guidance compared to the previous guideloksystems. The trough is still dispensed with and lightweight, slimline steel segments are fitted every two metres. Two automatically actuated rockers in the segments hold the chain in place and ensure quiet and smooth running. If the chain passes through the segment in the radius, the rocker is deactivated and the chain can free itself. Otherwise, the e-chain® is held firmly in the guide by the rockers. These locking levers are supplemented by open guide rails between the segments, which enables even greater dynamics and significantly reduces the noise level.

With the guidelok slimline F, suspended applications well over 50 metres can be realised, and even very fast-moving stacker cranes can be supplied with energy: travel speeds of up to 7 m/s and accelerations of up to 10 m/s2 are possible.

New system proves itself in practice
This system fits exactly into Winkel GmbH's required property profile and was installed accordingly. Both in the test installation, which has been in operation for more than 24 months, and in the first practical applications, the energy supply system has proved its worth. Thomas Riffert: "The chain is reliably held in position without rocking. In contrast to a conductor rail, we can also use the chain to transmit data, which means we don't need any additional optoelectronics." Another advantage is the maintenance-free operation of the chain system and the simple installation. And from a cost perspective, guidelok slimline F is also convincing in direct comparison with the busbar system.

Guidance, chain and cable from a single source - fully assembled
Winkel GmbH supplies the COLIBRI-RBGs with energy chain and guidance, but without filling - the customer takes care of this. Winkel recommends that users use chainflex®® cables from the igus® programme, which have been developed for use in moving systems. Most customers follow this recommendation and order ready-made readychain®® systems from igus®, which only need to be inserted into the chain and connected on site.
This saves time and costs, and simplifies logistics considerably - after all, the users of SRMs are all logistics igus experts. An additional argument in favour of delivery from a single source is the chain-cable guarantee provided by vonigus®.

At Winkel GmbH, not only the "hardware" of the energy chain system is emphasised positively, but also the good cooperation with igus®. ThomasRiffert: "If there is a problem somewhere, igus® is characterised by enormous openness. We work together to analyse what can be improved and quickly find an optimal solution."

Also suitable for pallet SRMs
Winkel GmbH is opening up new horizons with the COLIBRI concept, which has met with a very positive response. This is why the principle is now also being applied to pallet SRMs. Here, too, the same advantages are achieved - accelerated pallet handling and increased space utilisation. This corresponds to the Winkel GmbH motto "More space for higher performance." The new energy chain systems from igus® create a prerequisite for this.

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