Short stack bearing assembly
AssigneeCanadian Downhole Drill Systems Inc.
InventorsRaymond S. Livingston, David P. Kutinsky
Life of this patent
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Abstract
A mud motor bearing assembly is disclosed for an oil-lubricated downhole drill mud motor. A number of parallel sets of angular contact ball bearings are located between the mandrel and the bearing housing in a sealed, oil-filled chamber to provide all compressive thrust load bearing, extension thrust load bearing and radial load bearing capacity. Oil filled pistons at each end retard the progress of mud contamination into the inside of the chamber containing the ball bearings.
Claims18
An oil lubricated bearing assembly for a downhole mud motor comprising:
- (a) a hollow cylindrical housing having an upper end and a lower end,
- (b) a hollow cylindrical mandrel rotatably located in the housing;
- (c) upper and lower shoulder means on the inside of the housing, and on the outside of the mandrel;
- (d) two or ore angular contact ball bearing means arranged adjacent each other between the mandrel and the housing along the axis of the housing and mandrel, each bearing means having ball bearings carried in inner and outer races arranged around the mandrel at least two of said ball bearing means having at least one face on each of said inner and outer races in abutting contact with adjacent faces on the inner and outer races of an adjacent ball bearing means;
- and the inner races being retained between the shoulder means on the mandrel and the outer races between the shoulder means on the housing;
- (e) upper seal means between the mandrel and housing located between said upper end of the housing and said upper shoulder means;
- (f) lower seal means between the mandrel and housing located between said lower end of the housing and said lower shoulder means;
- (g) means for introducing and retaining lubrication within the housing means between the upper seal means and the lower seal means;
- and
- (h) wherein the upper and lower races of the respective ball bearing means are oriented such that at least one ball bearing means is arranged as a compression load bearing means and at least one ball bearing means is arranged as extension load bearing means.
The apparatus of claim any one of wherein the upper seal means and lower seal means each include piston means slidably located around the mandrel means in relatively liquid tight contact with the mandrel and the housing and capable of axial movement.
Dependencies are inferred from the claim text.