As an important power equipment, the technological progress and market performance of steam turbines have a significant impact on the development of new quality productive forces. In recent years, with the growth of market demand for steam turbines, the precision requirements for its core component, the steam turbine rotor, have been increasing. However, the machining of the 'narrow outside and wide inside' groove in large nuclear power steam turbine rotors domestically has always been a major factor restricting the output speed of domestic steam turbines. In traditional machining of the 'narrow outside and wide inside groove', 12 manual tool changes and re-alignments are required to complete the machining, resulting in low processing efficiency. Moreover, the main core technology machining accuracy cannot meet the standards, leaving the country long-term dependent on others.

As domestic technology continues to develop, this situation is gradually being broken. On December 12th, Qizhong CNC Equipment Co., Ltd. held a delivery ceremony for the heavy-duty CNC horizontal lathe it developed for Harbin Turbine Co., Ltd. at the equipment installation site. The product has overcome the technical difficulty of China's inability to meet precision indicators in processing large turbine rotors, solved the 'neck-choking' problem of high-precision processing equipment, and provided important support for the localization of core processing equipment for turbine rotors.

According to reporters, this heavy-duty numerical control horizontal lathe is a domestic equipment specifically designed for the machining of high-precision parts such as large steam turbine rotors for nuclear power. It can fully meet the requirements of key technical indicators. It is an independently intellectual property product with higher efficiency, higher precision, higher rigidity, and higher reliability. The maximum turning diameter of the machine tool is 4.5 meters, the maximum workpiece length is 16 meters, the maximum workpiece weight is 350 tons, and the spindle end/radial runout reaches 0.005mm.

It is worth noting that to solve the machining challenge of the 'narrow outside and wide inside' groove, the project team overcame the fully automatic angular tilting tool plate technology. This allows the tool plate to arrange mechanisms with transmission, indexing, and locking functions within a narrow space of less than 60mm, and enables complete cutting processing on this basis. This has increased the machining efficiency by 3-4 times, making this technology the first of its kind in China for the same specification machining equipment.

In addition, the size and precision requirements of steam turbine rotors are extremely strict, especially the stability of the workpiece runout accuracy, which directly affects the reliability of the steam turbine rotor. To overcome this challenge, R&D personnel simulated and analyzed the stress state of the gear ring using virtual machine tool technology, improved the spindle support structure, optimized the machining process, strictly controlled the precision of basic parts, and innovated the assembly process. As a result, the on-site measured radial runout of the machine tool spindle end was 0.005mm, fully meeting the processing requirements of the rotor. This product is also suitable for heavy-duty shafts and other rotating parts, such as the outer cylindrical surface, conical surface, end face, groove, thread, and rotating curved surface turning processing of parts like large motor shafts, generator shafts, and motor rotors.