HYDRAULIC DAMPER Russian patent published in 1996 - IPC

FIELD: well drilling. SUBSTANCE: hydromechanical damper has a case, upper reducer with extender and axial channels. Internal surface of the upper reducer is made in the form of a converging tube. A cylinder in the form of truncated cone is installed in the upper part of hollow shaft. The cylinder is provided with mixing chamber and axial and tangential passages. Replaceable extension is installed in the axial passage. Packages of metal rings with elastic members are installed between the case and hollow shaft. The members have variable characteristics. Limiting sleeve and spline spring. Elastic members have lengthwise openings. Cross section of the openings is risen from the top to the bottom. EFFECT: high efficiency. 3 dwg