DOWNHOLE DEVICE WITH ROTATING ASSEMBLIES RESISTANT TO FORMATION OF DEPOSITIONS (VERSIONS) Russian patent published in 2013 - IPC E21B4/00 

FIELD: mining.

SUBSTANCE: downhole device includes a housing with a channel passing along its axis, a shaft located in the housing and passing through the channel. The shaft is installed so that it can be rotated in axial direction within restricted limits. Downhole device includes a radial bearing arranged in the housing channel to support the shaft. The bearing includes an insert installed in the housing and a sleeve installed on the shaft. The sleeve and the insert have the possibility of interaction. The sleeve has the possibility of being rotated along the housing axis and moved in axial direction together with the shaft. With that, there is a gap between inside diameter of the insert and outside diameter of the sleeve. One of the bearing elements, either the sleeve or the insert, has a smaller axial gap than the other one. Axial ends of the element having the smaller axial size never project beyond axial ends of the other element. As per the other version of the invention, one of the bearing elements, either the sleeve or the insert, has a sharp angle on its axial end for scraping depositions off the interacting surface of the other element.

EFFECT: reduction of formation of depositions in radial bearings for downhole devices.