Gear production is speeding up
22.01.2014 - Oliver Hagenlocher
Drivers have already become used to the sixth gear – and the development continues. For instance, there are plans afoot for a 9-gear transmission system for automatics gearboxes. The reason is an obvious one: it allows for the car to be driven at optimal speed for longer. That saves petrol. The development goes hand in hand with the continuing pressure to optimise. High volume gear production must become faster and cheaper. How it can be done was demonstrated by the EMAG Group: Their VLC 200 H Vertical Hobbing Machine adds a new dimension to productivity levels.
According to the German Federal Statistical Office, German companies in the transmission sector generated a combined turnover of over 17 billion EURO last year alone, with the trend continuing to be an upward one. The constantly increasing production volume keeps the industry firmly in the mind of production planners, especially those in the automotive industry, where they are asking for a faster, more efficient production. At the same time they want guarantees that an increasingly demanding component quality is maintained. All this should not come as a surprise, considering transmission technology accounts for a large percentage of the research costs in the automotive industry, according to the experts.
The modular platform in action
The experts of the EMAG subsidiary KOEPFER, with headquarters in Villingen-Schwenningen, are no strangers to this kind of dynamics. They have, for decades now, invested heavily in developments in this industry. KOEPFER is not just a supplier of machines for the high-quality gear production, but also a competent partner for anything to do with “the gear”. The latest result of these efforts represents a veritable milestone, as it is a product of close collaboration within the EMAG Group: The VLC 200 H vertical hobber is the first KOEPFER machine that is based on the new modular standards of EMAG. It is also the name of a “standard” machine platform that represents a new generation of machine tools for use in a range of greatly varying applications. This “modular approach“ is of great advantage when it comes to establishing a highly efficient production system for the transmission industry, as it allows for the individual processes used in the soft machining of a gear – from turning of the raw-part to hobbing and finally deburring – to be combined with perfection and without any great outlay for automation. “The machines are easy to interlink, as they are perfectly coordinated and also work at the same transfer height, for instance“, explains Jörg Lohmann of KOEPFER.
Short cycle times
A closer look at the VLC 200 H hobbing machine reveals a technology that offers the user great economic advantages, even in its stand-alone version. The machine features high-performance drives that offer great main spindle and hobbing speeds. Gears of a maximal diameter of 200 mm and module 4 can be dry-milled at greatly shortened cycle times. Removal of the hot chips generated by the process is no problem on vertical machines, where they fall unhindered into the chip conveyor below. The typical EMAG pick-up design principle also provides for short idle times. The main spindle removes the raw-part from the conveyor belt, takes it to the tailstock – where it is very firmly supported during machining by a tailstock flange – and removes it from the machining area after completion of the hobbing cycle. This concept of an integrated automation system, with its short travels, not only makes for great speed, but also guarantees a high degree of machine availability.
The VLC 200 H also guarantees exceptional and consistent component quality. This it owes, in part, to the vibration-resistant polymer concrete MINERALIT® used for the machine base. An optional measuring probe can be integrated into the machining area and used either for positioning tasks or for the measuring of finish-machined components. “It even allows us to carry out adjustments in the machining process. In fact, the whole machine provides added value with its production process-internal quality control”, confirms Herr Lohmann.
Flexibility in production systems
Where this automated “high-efficiency package”, designed on the basis of a modular platform, is to be integrated into a manufacturing system, the production planner has a choice. He can go for directional component flow, recirculating automation or the “chaku-chaku” principle. A processing concept, meticulously planned by EMAG experts, ensures lowest cycle times: after turning of the raw-parts (for instance on a VL 2 from EMAG), the gear cutting process is carried out on the VLC 200 H, with the final processing – deburring and single-sided chamfering – being done on the VLC100 D. And all machines involved are designed on the basis of the “modular standard” from EMAG. The decisive advantage: the gearing is generated in a single cut and followed only by chamfering, whereas alternative production solutions rely on a second cut after chamfering. With modular EMAG solutions and KOEPFER technology your cycle times for the machining of gears will drop dramatically.
Herr Lohmann considers the market opportunities for the VLC 200 H from KOEPFER as brilliant: “When it comes to optimising a large-volume gear production or developing a new one, we offer a highly efficient solution with integrated automation that can be configured a number of different ways. It should signal a very interesting approach to every production planner.”