Machining and equipment configuration of locomotive diesel engine crankshaft

The crankshaft is a critical component in diesel engines, subjected not only to gas pressure, inertial forces, and centrifugal forces but also to additional stresses caused by torsional vibrations. As one of the most important moving parts, it requires high strength, precise manufacturing, and complex processing techniques, which contribute to its high cost. The design and production of a locomotive diesel engine crankshaft involve careful consideration of size, material, and performance requirements. Due to space constraints in locomotives, diesel engines are typically 4–6 meters long and 2.5–3 meters wide, resulting in crankshafts that are generally around 4 meters in length. The main journals of these crankshafts come in various diameters, such as φ190mm, φ220mm, φ230mm, and φ250mm, while the crankpins (connecting rod journals) are smaller. These dimensions are crucial for ensuring the structural integrity and performance of the engine. Mounted on the crankcase bearings, the crankshaft connects to the piston-connecting rod assembly, driving the traction motor through a coupling at the output end. On the free end, it drives components like the camshaft and oil pump via gear transmission, and even auxiliary devices through a cardan shaft. This complex system demands high precision, durability, and reliability. In addition to mechanical loads, the crankshaft must withstand fatigue damage due to stress concentration from large cross-section changes and poor rigidity, making deformation and vibration more likely. To mitigate these issues, advanced heat treatment and surface strengthening techniques—such as intermediate frequency quenching, nitriding, shot peening, and roll forming—are commonly used. Moreover, dynamic balancing is essential, especially for medium- to high-speed locomotive diesel engines. Crankshafts can be made from cast ductile iron or fully forged alloy steel, with different processing methods required for each. Alloy steel crankshafts, produced using full-fiber extrusion, are known for their superior mechanical properties and are widely used in modern locomotive engines. The machining process for locomotive diesel engine crankshafts includes roughing, semi-finishing, and finishing operations. Key steps involve quenching and tempering, drilling oil passages, and surface hardening. After final grinding and polishing, the crankshaft undergoes dynamic balance testing and oil pumping checks before being delivered. Early crankshaft production relied on conventional machine tools such as lathes, grinders, and milling machines. Over time, specialized production lines were developed to streamline the process, reduce transportation, and improve efficiency. However, with the advancement of CNC technology, modern equipment such as turning-milling centers, boring-milling centers, and crankshaft grinders have become dominant. Leading manufacturers like WFL, NILES-SIMONS, and NAXOS offer high-precision solutions, significantly improving machining accuracy and reducing labor intensity. These systems allow for integrated machining, minimizing setup times and enhancing flexibility. In recent years, domestic manufacturers have also made significant progress, offering cost-effective alternatives without sacrificing quality. With the introduction of advanced machinery, the layout of the production line has evolved, requiring better environmental control, such as fully enclosed air-conditioned workshops. While imported equipment offers higher precision, domestic alternatives provide a more economical option, especially for mid-sized production runs. Overall, the evolution of crankshaft manufacturing reflects continuous improvements in technology, efficiency, and cost-effectiveness, ensuring reliable performance in locomotive diesel engines.

CS02A Lithium Battery Mini Electric Screwdriver

SUZHOU CREATION SPACE INTELLIGENT TECHNOLOGY CO.,LTD , https://www.mypkey.com