HELICAL GEAR ROTATION MECHANICAL OF SCREW HYDRAULIC MACHINE Russian patent published in 2003 - IPC

FIELD: mechanical engineering. SUBSTANCE: invention can be used for drilling oil and gas wells at designing of working members of screw downhole motor. Stator and rotor teeth of helical gear rotation mechanism with internal cycloidal meshing are made with displacement of profile and are in continuous interference contact. Surfaces of stator and rotor teeth and their end face surfaces are geometrically conjugated with generating surface of hob designed from original profile of rack described by equidistant curve of curtate cycloid for mechanism with normalized axial pitch. Ratio of measured axial pitch P of mechanism to normalized pitch pH is limited by internal 0.85-2.3. Variable value of pitch P and value of axial pitch t of hob are related by condition of coincidence of tangential lines to screw lines of surfaces of stator and rotor teeth and generating surface of hob on their initial gage cylinders. EFFECT: reduced cost of mechanisms owing to provision of changing of axial pitch with in rational limits. 12 dwg