The market for large gear wheels is growing – in a great variety of industries: wind turbines, construction vehicles and ships need transmission systems that use large gear wheels to move very large masses. The gearing experts at LMT Fette know exactly what kind of challenge is involved in producing these components. LMT gear cutters and hobs offer considerable advantages also and especially in demanding finishing applications.

In this year alone, according to forecasts by the World Wind Energy Association, installed wind power capacity worldwide will increase by over 16 percent. By the end of the year, wind turbines will be able to generate up to 273,000 megawatts of electricity. (In comparison, the output of all the world’s operating nuclear power plants currently totals nearly 390,000 megawatts.) And this boom is continuing: green electricity’s share of the global energy mix is rapidly increasing, say the experts (more information is available here). However, other industries that rely on large gears are also booming. For example, according to the German Association of the Automotive Industry (VDA), the global market for heavy commercial vehicles will grow by five percent this year.

Focus on cutting processes

What impact is this dynamic growth having on the production of the gears used in wind turbines, large commercial vehicles, building equipment and mining technology? “Requirements in many sectors have increased massively,” explains Thomas Falk, who is responsible for gear cutting at LMT Tools. “Wind turbine engineering makes that especially clear. These installations are not only getting larger and larger, but they also have to be able to work longer without breakdowns. That naturally also applies to transmission systems and gears.” As a result, very special attention is being paid to cutting processes. It is important here not only to machine components swiftly and efficiently, but also to achieve the highest possible surface quality during the finishing process. “When it comes to very large gear elements, machining quality and tolerances also and especially play a great role,” confirms Falk. “Ultimately they are responsible for the efficiency of the overall transmission system.”

Tailormade solutions for individual components

The machining is carried out using hobs or gear cutters – each with indexable inserts. Both types of tools can be used for both roughing and finishing. The choice depends on batch size or the required number of cogs. “This is where customers benefit from LMT’s extensive range of tools and our pool of knowledge and experience. We can provide very exact advice when, for example, the blueprint of the component is available and the customer’s operating conditions are known. We can then develop the most efficient tool solution,” explains Falk.

The great benefits of LMT tools then become evident in practical use. On the one hand, the standardized and readily available range of indexable inserts and standardized tool bodies keep costs low for users. On the other, LMT specialists have developed innovations that guarantee quantum leaps in machining performance. Examples of this include the new LCP35H cutting material and the new range of sizes for gear cutters:

LMT developers combined an extremely tough ultra-fine-grain carbide with the wear-resistant Nanotherm coating for the LCP35H. This combination significantly boosts performance in wet machining, for example, and prevents the formation of fractures. This increases the operating life of the indexable insert and also makes the process extremely reliable.
The new gear cutters with standardized indexable inserts for roughing stand out because of their very smooth cut in practical operation. LMT FETTE designs the desired tooth flank contour to meet customers’ requirements. This gives rise to powerful roughing and finishing tools that guarantee the highly cost-effective production of gear wheels.

Tool solutions for every application

“Overall, we can provide appropriate tool solutions for all applications in the large gear sector. We are a technology leader here – especially when it comes to perfect surface qualities and the lowest possible machining tolerances. This combination is giving us major opportunities in an increasingly important market,” Falk sums up the enormous potential opening up for LMT Fette.