A theoretical basis for the methods to restore working capacity of valve-actiating gear of the cylinder block head

Introduction. The article describes the method of reliability improvement of the valve-actiating gear of the cylinder block head. Material and Methods. The method of the dimensional analysis was used for definition of the possible travel of hydro compensator valve mechanisms in the new and used cylinder heads of ZMZ 406 motor. The method is based on micrometer research and precise calculations. Results. The hydro compensator travel in the valve mechanisms of new motor cylinder heads of ZMZ-406 engine is 2.3 mm with maximum deviations of ±0.15 mm. An estimation of dimensional chain was calculated for the rational methods of recovery. The limit values of surface wear were used as the limits of component links. The values were obtained using micrometer researches of used heads of cylinder blocks. When the best combination of wear, possible hydrocompensator travel is 1.98 mm, and when the worst one minus is 0.74 mm, that is, the hydrocompensator travel is not enough to compensate for the wear of component parts. Discussion and Conclusions. The authors of the article propose four ways to improve efficiency of valve mechanisms. As a criterion for selecting a method of repair is proposed to use the total value of the valve. Sinkage for the proposed methods, hydrocompensator travel after repair is from 1.57 to 2.36 mm, which corresponds to the hydrocompensator travel of the new motor cylinder heads.