New, innovative grinding tools for machining gear wheels in large gearboxes
The enormous competitive pressure in the sector of large gearbox manufacturers forces companies to make increasing cost reductions. Particularly when it comes to the hard finishing of large gear wheels, special attention is paid to the grinding process, as it is one of the most important, but also one of the most cost intensive work processes. Besides the need to grind without cracks or thermal damage, the requirement to reduce the noise of the gears using more precisely modified tooth profiles and increasingly high surface requirements also determines the grinding process. In most cases this leads to prolonged grinding times and lower tool downtimes due to the dressing of the grinding tools. One reason for the loss of grinding performance is the clogging of the grinding disc from the metal chips removed. Not only does the grinding disc lose its cutting ability here, but the risk of burning also increases relatively highly. In many cases, the pore space is merely seen as a transport space for the cooling lubricant. A key job of the pores is to take away the stock and hence the introduced heat from the workpiece. Nevertheless, the chips often penetrate deep into the pores of the grinding tool during the process. In a joint development project with the customer, THELEICO worked out a solution to this problem. By precisely matching the ceramic bonding system with a new grain combination, the self-sharpening effect was optimised. At the same time the geometry of the pore space was modified. These steps led to a much improved stock removal. The tool newly developed for this grinding operation has a much longer service life compared to the sintered corundum grinding discs commonly used today. In this special case we were able to reduce the overall tool costs by 50%. The over 130-year old family company, THELEICO, develops and produces special tools for precision grinding that are matched to the respective application.