RADIAL BEARING FOR DOWNHOLE MOTOR Russian patent published in 2005 - IPC

FIELD: well drilling equipment, particularly bearings adapted to work in abrasive medium.

SUBSTANCE: radial bearing has body and shaft, as well as thrust collars secured in the body and spring-loaded holders arranged between the shaft and the body. Inserts with conical outer surfaces are located between the holders and the shaft so that inserts cooperate with the shaft and with inner surfaces of the holders. Radial bearing is made as two oppositely arranged blocks and as compression spring inserted in-between. Each block has stop member secured in the body and made as slotted bush. Inserts are arranged in the bush and may perform displacement in radial direction. Thrust collars have conical surfaces cooperating with outer surfaces of the inserts. Angles α at apexes of the cones defined by interacted conical surfaces of bearing support inserts, thrust collars and holders are correlated with friction coefficient μ of interacted surfaces as tg(α/2)≈μ. Insert surfaces cooperating with shaft surface may have coating of elastomeric or hard-alloy material. In accordance with the second embodiment surfaces of inserts, thrust collars and holders interacting one with another may have flat contact zones, which are inclined at (α/2) angle to longitudinal shaft axis.

EFFECT: increased operational reliability of radial bearing.

6 cl, 3 dwg