DRIVE SHAFT OF HYDRAULIC DOWNHOLE MOTOR Russian patent published in 2010 - IPC E21B4/02 F16D3/16 

FIELD: machine building.

SUBSTANCE: drive shaft comprises central shaft and two case couplings with driving mechanisms. Each case coupling consists of male and female parts. In female part of each case coupling joined to central shaft there is a row of grooves and peripheral surface that holds driving mechanism and includes ledges and segment supports with flat surface, which movably contact with specified side surfaces of grooves. Central shaft and male parts of both case couplings are arranged in the form of integral module. Between ends of female parts of case couplings there are spherical supports and spherical step-bearings. Each edge of integral module comprises stiffeners of ledges intended for support against bent surfaces of each segment support. At the same time in each female part of case coupling there is a thrust split bushing installed and fixed by nut, and also there are receiving cavities for arrangement of according ledge stiffeners at the edge of integral module.

EFFECT: improved resource and reliability of device, improved weight and dimension characteristics.

4 cl, 8 dwg