Papers by Keyword: Friction Units

Abstract: The study considers the theoretical and technological aspects of the friction units’ resource increasing made of ferritic-pearlitic gray cast iron. It is found that chemical and thermal treatment has the best combination of criteria by the integrated technical and economic analysis for the cast iron parts’ hardening methods. The methods of the cast iron hardening used in practice are not applicable in the real production conditions. It happens because of the technological processes’ complexity and the equipment. Alternatively, the hardened layer thickness does not exceed 0.3 mm. The study considers the main aspects of the new technology application for the surface hardening, The recommendations for its application are formulated. They depend on the intended service of the part. The technical level of the offered solutions is estimated in comparison with traditional technologies of cast iron hardening.

Abstract: Existing laser honing machines all utilize the motion mode of workpiece movement. But as to complex workpiece, this mode is inappropriate to use. For example, cylinder liner, pre-casted into the engine block, is not suitable to rotate when fixed on the chuck, because the block is irregular and heavy. This equipment uses the mode of laser head rotation and linear motion. The workpiece keeps still during the laser texturing process. In this paper, the structure design and control principle of the laser machine are narrated in detail. The process of the machine is a new method of laser micro-texturing, named as “single-pulse interval of the same point many times”. The method contributes to processing microscopic or macroscopic morphology and significantly reduces the negative thermal effects of laser processing

Abstract: The laser honing technique is a new surface texturing technique. As the piston ring at the top or lower oil attachment point works under worse lubrication condition, its wear increases severely, laser texturing was used to the piston ring/liner, lineary extending grooves and regular arranged dimples with predetermined parameters was well-matched with the needs of lubrication. The effects of different dimple shapes, such as sphere coronal, combined sphere coronal ,columnar, hexahedral, and trapezoidal dimples was analyzed by the theory of hydrodynamic lubrication. It was deduced that trapezoidal dimples are fit for only single running orientation and sphere coronal and combined sphere coronal dimples are fit for double running orientations. The experimental researches show that laser texturing not only can reduce the oil consumption and the cost of engine but also can prolong its work life.