Abstract
A support control automation system employing force sensors to a large-size crankshaft main journals’ flexible support-system was studied. The current system was intended to evaluate the geometric condition of crankshafts in internal combustion diesel engines. The support reaction forces were changed to minimize the crankshaft elastic deflection as a function of the crank angle. The aim of this research was to verify the hypothesis that the mentioned change can be expressed by a monoharmonic model regardless of a crankshaft structure. The authors’ investigations have confirmed this hypothesis. It was also shown that an algorithmic approach improved the mathematical model mapping with the reaction forces due to faster and more accurate calculations of a phase shift angle. The verification of the model for crankshafts with different structural designs made it possible to assess how well the model fits the coefficients of determination that were calculated with the finite element analysis (FEA). For the crankshafts analyzed, the coefficients of determination R2 were greater than 0.9997, while the maximum relative percentage errors δmax were up to 1.0228%. These values can be considered highly satisfactory for the assessment of the conducted study.
Highlights
The measurement of geometric deviations comprises issues that focus mostly on measuring small-sized components [1,2,3,4]
Based on our previous research, we considered large crankshafts to be those where the length-to-diameter ratio (L/d) is greater than 12/15, whereas the shape factor αk determining the nature of cross-sectional changes may take on significant values αk > 1 [17]
Assuming that the reaction forces calculated with the finite element analysis (FEA) software at the support of a given journal for successive shaft positions are expressed in the form of a vector: ΦFEA = [φ1, φ2, . . . φm ], (2)
Summary
The measurement of geometric deviations comprises issues that focus mostly on measuring small-sized components [1,2,3,4] This limitation is due to the use of small structural components in machinery and mechanisms and the availability of comprehensive instrumentation for measurements. The crankshafts of piston power machinery used in shipbuilding and in other modes of transport such as railway or automobiles, agriculture, industrial construction and emergency power sources for military facilities and public utilities such as hospitals and offices These shafts, in addition to their considerable weight and dimensions, have relatively small ratio of cross-section to length. A number of other structural details make them different
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.