METHOD OF EVALUATION OF CONDITION OF MATED PARTS Russian patent published in 2004 - IPC

FIELD: mechanical engineering; engines.

SUBSTANCE: invention relates to acoustic diagnostic methods and it can be used for checking condition of parts of internal combustion engine valve actuating mechanism. According to proposed method air leakage past mated surfaces of parts is measured and diagram is plotted representing changes of microirregularities and area of contact at different air leakages, then harmonic oscillations at natural frequencies are excited whose form is determined by equation ϕ(x)=A[S(B_m/l^.x)-V(B_m)/U(B_m)^.T(B_m/l^.x)] where S, V, U, T are Krilov functions; B_m is root of characteristic equation; x are coordinates along longitudinal axis of part, m; A is constant coefficient found from boundary conditions; 1 is length of part, m. _m - are 1, 2, 3 … . Shifting of frequency of natural oscillations and intensity of wave at natural oscillation frequency at propagation of elastic waves through layer formed by microirregularities in mated surfaces. If shifting of natural oscillations frequency and intensity of wave at natural oscillations frequency lies out of zone of tolerable values, mated parts do not provide required degree of sealing.

EFFECT: improved accuracy and provision of reliable evaluation of condition of mated parts of piston machine, reduced labor input at diagnosing.

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