A new method of gear cutting on the mill crown was successfully tested

April 28, 2020

In the process of manufacturing the mill MMS-9500×2900 for Lebedinsky GOK, JSC TYAZHMASH specialists applied a new method of gear cutting on the crown. The result was successful and significantly reduced the labor intensity of production of the entire machine.

Normally, gear cutting is performed on a mill crown using specialized gear cutting machines. In addition to gear cutting (basic) operation, auxiliary operations on boring-and-turning, boring and drilling machines are also performed, which ultimately requires a lot of effort and time. In this case the specificity of the work was also in the assembly unit dimensions: the outer diameter of the crown is 8,058 mm, width — 1,000 mm, module — 28, and weight — 57,370 kg. Thus, gear cutting was possible only on the KU-306 machine, which is currently undergoing modernization, at the stage of commissioning and acceptance.

However, a solution was found. The specialists designed a scheme of crown installation and created a control program for gear pre-cutting using end mills on another equipment — horizontal boring machine NS17F2, which recently was returned to operation after serious reconstruction and was equipped with a CNC system and a rotary work table. The finishing operation was carried out on a gear milling semiautomatic machine 5355C, for which they invented a new scheme using unloading roller supports. As a result, the total milling operation time was 821 hours compared to the usual 1,366 hours, i.e. the productivity was increased by 1.7 times.