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Optimized Solutions for Every Aspect of Gear Grinding

Optimized Solutions for Every Aspect of Gear Grinding

Tyrolit is manufacturing to meet today’s needs of high-quality gearing tools at a reasonable cost

By: Karl-Heinz Gies

Today, there are ever increasing quality requirements from gear manufacturers, along with constant demands for cost reduction. Having a broad range of different grinding and dressing tools means Tyrolit can offer a host of solutions to customers, tailored exactly to their specific needs. As a gear manufacturing specialist, the company can optimize processes on location, saving the operator time and money.

In many areas of technology, transmissions and their components make an ever-increasing, valuable contribution to the safe, long-term operation of products, not just in terms of efficiency and lifetime, but also energy consumption, emissions, and economic efficiency.

In today’s engineering industry – specifically in the automotive and aircraft industries, wind turbine operators and other power generators – the performance demanded from gear wheels and shafts is more or less the same. There is a demand for surfaces with a constantly improving finish and optimized geometries.

In this way, the percentage contact area is increased, which in turn makes for even better power transfer. As a result, gear wheels can be made smaller with the same performance, which reduces the weight of both gear and shaft. In the drive train, this decreases energy consumption, with the further benefit of reduced emission of polluting exhaust gases. At the same time, a better finish of the contact area promotes smooth running, i.e. lower noise, with the added benefit of an increase in component lifetime.

However, machining requirements of hardened gear surfaces differ significantly from one use case to the next. There are major differences in size and design, which in turn demand a plethora of different tools. Not surprisingly, a great variety of machining concepts are employed. These range from intermittent profile grinding, through bevel gear grinding and continuous generating grinding to power honing.

A comprehensive product range

Whereas some suppliers concentrate on a limited range of specific technologies, Tyrolit is a system supplier that covers every aspect of gearing and is therefore able to offer its customers truly optimised solutions that meet virtually every tooling and process technology requirement. The range of bonded grinding wheels is further enhanced by dressing tools which Tyrolit – as one of the leading manufacturers of bonded grinding tools – offers to all its customers worldwide.

The many different Tyrolit product lines, in particular MIRA Ultra, MIRA Ice, MIRA Alpha and MIRA Ultra SF worm grinding wheels, the Mira BK, MIRA Ice BK and MIRA Alpha BK single profile grinding wheels, the MIRA REX honing rings and the MIRA DDG dressing gears are equally well-known products for gear machining.

They offer outstanding performance in everyday use, not merely because of their stock removal rate, but above all, because of their consistent product quality, which optimizes the manufacturing process and makes it safer. Apart from the cool cut which is reflected in the name MIRA Ice, it boasts other features such as shape retention, extended dressing cycles, long-lasting sharpness and maintenance of contour.

Technical consultancy services

This short list of the different types of MIRA grinding tools alone shows that no two grinding wheels are alike. Local ambient conditions at a customer’s site also have a significant effect on the grinding results and the requirements that need to be met. This starts with the machinery used and the clamping of the component, and continues with process parameters, cooling lubricants, their quantity and temperature, right up to handling and conditioning of the grinding wheels.

All this goes far beyond the production of grinding wheels for hard finishing of gears, which Tyrolit carries out exclusively at its plants in Austria and Germany. Apart from product know-how, Tyrolit’s development and application engineers need to have extensive experience with engineering processes and knowledge of the effects to be expected when certain machining parameters are changed.

To ensure meaningful communication between its development engineers in the field of gearing and to provide a knowledge base that is up to date at all times, Tyrolit has set up a Competence Centre at Neuenrade (not far from Dortmund).

This centre looks after all customers that are involved in the gearbox business and in gear machining, for the benefit of everyone. From here, Tyrolit application engineering teams can respond quickly with development and implementation support and can offer customer-specific solutions, always with the option of referring back to a strong development team at the company’s Head Office in Schwarz (Austria).

This Competence Centre also offers machines for trialling purposes and process development, making it possible to provide the client not just with products, but with safe and reliable processes. As a rule, these are optimized further by application engineering teams that will work on the customer’s own premises. This ensures the ongoing further development of Tyrolit products.

More cost-effective customer processes

Apart from offering reliable products, Tyrolit’s position as technical market leader also relies on further technological development. The performance of the deployed machines is becoming more efficient. Therefore, grinding tools used must keep up with the development process. For example, the MIRA Ultra, MIRA Ice and MIRA Alpha worm grinding wheels now have operating speeds of up to 80 m/s.

This creates the highest chip removal rate over time, which for the operator means the shortest possible grinding time. At the same time, these worm grinding wheels still produce the well-known cool cut and have a high resistance to burning.

The known homogeneity of the grinding body is a guarantee for high, reproducible grinding quality.

When it comes to generating grinding, Tyrolit dedicates much time to the so-called superfinishing process which involves the MIRA Ultra SF product range and polish grinding. Again, working speeds of 80 m/s are mainly used.

Thanks to the development of a novel kind of worm grinding wheel with two different machining zones: one with ceramic bonding, the other epoxy resin-bonded, pre-grinding, finish grinding and superfinishing can now be performed with a single clamping operation, with a single tool. This saves customers long processing times, enables surface accuracies of Ra 0.05μm and improves productivity.

Tyrolit has also improved and completed the honing rings product assortment. The new honing rings MIRA REX VTEC-20, VTEC-30, VTEC-40 und VTEC-50 offer further advantages, especially when used on machines with path-controlled dressing tools (VSD). With the new 2-zone composite design MIRA REX COMP range, technically optimised and adapted honing wheels for power honing were launched.

The abrasive inner ring is produced using vitrified bonding. The outer ring is made of an PU bonding without abrasive grains. A patent application was filed for this innovative honing wheel design. With the additional performance upgrade with the specifications MIRA REX-580, REX-1200 and REX-1300, Tyrolit offers best technical solutions. By employing “gentler” honing, machining times can be shortened and/or dressing cycles extended. At the same time, the risk of breakage of overstressed honing rings is reduced.

Next, Tyrolit plans to offer an additional component acceptance service on a high-performance honing machine for MIRA DDG (diamond dressing gears). The standard quality assessment is made on the MIRA DDG dressing gear wheel.

With the additional workpiece acceptance offered, quality assessment then takes place by reference to the honed workpiece. Along with the workpiece, the customer is provided the acceptance diagram and the directly adapted honing ring. This means that the customer is fully aware of the results that can be expected in actual production. It is also acts as an investment guarantee and assurance of uninterrupted production.

New techniques

Working closely with manufacturers of machinery and in its own development department, Tyrolit is now investigating news in dressing techniques and in the development of innovative dressing tools. Ultimately, the frequency of the necessary dressing operations not only affects their productivity, but also the cost of dressing tools and of the actual grinding wheels.

Dressing also means wear and tear on both sides. Optimization means immediate cost savings. Tyrolit translates customer needs into action.