Block Design And Structure Strength Study Of Low-speed Marine Single-cylinder Diesel Engine

Diesel engine is an important source of marine power,the reliability of diesel engine structure will directly affect the safe operation of the ship.Airframe components constitute the basic skeleton of the diesel engine,which is mainly used for installation of moving parts and subsidiary bodies to ensure that they have the correct working position.Its strength and stiffness is the fundamental premise for ensuring the safe operation of the engine.Reasonable design the structure of the diesel engine airframe components can ensure the strength and stiffness of the body’s requirements.It is necessary to make the analysis and calculation in the design process,in order to propose a reasonable improvement and effective optimization advice of the design,and ultimately get more ideal design effect.The block component of the single cylinder diesel engine was redesigned by reference to the domestic import licensing production of engine block structure and combining with the design requirements in this paper.Two solutions are proposed for installation and configuration of the balance system,and completed the three-dimensional modeling.The shaft structure of single cylinder diesel engine balance system was designed,and a kind of bearing structure which can adjust the concentricity of the balance shaft is proposed.Theoretical strength of the balance shaft is checked,and the results show shafts is safe.Finite element analysis which is a numerical analysis method has been widely used in engineering field,and it can effectively solve the problems of complex structures.The finite element model is established according to the redesign of the two sets of diesel engine components.Finite element analysis of two projects of the body component of single cylinder diesel engine is carried out in the bolt preload working conditions and the maximum explosion pressure.The calculation results show that all the body components have good strength and rigidity,and the body component does not appear the phenomenon of large deformation or fracture in the working process.It is seen from the components of the stress and displacement nephogram that dangerous areas appear around the bolt hole.Stress concentration is reduced by improving the structure of nut and increase the area of contact.It can provide a certain theoretical basis for the design and optimization of diesel machine body structure.The frame is not only to endure all kinds of assembly force,but also bear to the side thrust which was generated by the reciprocating motion of the crosshead slide assembly in the work process.The finite element model was established,aiming at the effects of side thrust on single cylinder machine frame.Research and analysis the stress and deformation distribution of the overall frame and guide was in the side thrust at maximum.From the stress and deformation contours it can be clearly seen the whole frame has good strength and rigidity,Rack guide connection position and the bearing seat appeared obvious stress concentration phenomenon,but the stress concentration will not pose a direct threat to the block.