Gearwheels production often means mass production. In the automotive industry, for example, the main components for gearboxes are required in huge quantities. Accordingly, if there is an increase in car production, the demand for gearwheels rises exponentially. So how can automotive suppliers open up new production capacities in such situations – while simultaneously minimizing the production costs of their components? Gearwheel experts from LMT TOOL SYSTEMS have demonstrated one way of doing just that with its customer Stelter Zahnradfabrik. Stelter was able to free up machine capacities simply by deploying the new Speedcore hob. The tool’s incredible performance eventually tipped the balance for the company.
The specialists at Stelter have known for decades that the production of gearwheels is a high-precision business. Its customers include international engineering, energy and automotive companies. Very different products ranging from enormous gears for wind turbine transmission systems to the smallest of cogs with a diameter of eight millimetres are all produced at the company’s site in Bassum near Bremen. However, all these components share Stelter’s high quality standards: high technology and specialist know-how ensure a zero-fault strategy. Permitted production tolerances are minimal for every single gearwheel.
Focus on tools
It should therefore go without saying that Stelter subjects gear-cutting tools to extremely close scrutiny. They must not only meet the company’s high quality standards, but also enable efficient, high-speed production. It is not very surprising then that production planners very quickly initiated performance tests with the SpeedCore hob after it was launched by LMT FETTE in June. After all, the performance claims made by LMT’s tool experts in the run-up to the launch were rather amazing: higher cutting speeds enable users to increase productivity by over 30% compared to hobs made of powder metallurgical high-speed steel. According to the LMT developers, this increase is made possible by a new cutting material that forms the core of the hob and facilitates much higher cutting speeds.
Massive productivity hike
Were these claims confirmed by the customer? “Absolutely,” explains Karl-Heinz Wilkens, production engineer at Stelter. “These incredible performance figures were also substantiated in production tests on a gearwheel with module 1.71.” Compared with the previously used PM-HSS tool, it was possible to increase the cutting speed from 150 to 225 metres a minute. The machining time per workpiece was thus reduced from 0.54 to 0.35 minutes. “When you consider that this gearwheel is produced in enormous batch sizes and the machinery is in operation for 24 hours a day, 6 days a week, you begin to realize what kind of possibilities the SpeedCore hob opens up. When it comes down to it, significantly higher numbers of gearwheels can be produced in the same time on the same machine,” adds Torsten Oellers, gear-cutting application engineer at LMT FETTE.
Reconditioning and recoating at LMT
LMT offers a complete system package for the production of gearwheels. It also includes specific engineering and a range of services. With sites in Germany, the USA and China, LMT guarantees the global reconditioning of its hobs to original manufacturer quality. Stelter, for example, also makes use of this expertise: SpeedCore hobs used by the gearwheel specialists are reconditioned and recoated at the LMT FETTE plant in Schwarzenbek near Hamburg. “The system package perfectly matches the possibilities offered by the SpeedCore hob,” explains Thomas Falk, head of the gear-cutting segment at LMT TOOL SYSTEMS. “It offers unique opportunities, especially when it comes to fully exploiting gear production potentials and increasing production volumes. Increased demand in many sectors is therefore opening up considerable market opportunities for SpeedCore.”