Well drilling tool with diamond radial/thrust bearings

A bearing pack for a down hole well drilling tool comprising

• a bearing housing adapted to be connected to the housing of a well-drilling, fluid actuated down-hole motor,
• a rotary bearing shaft positioned in said bearing housing having one end adapted to support a drill bit and another end adapted to be driven with a rotary shaft of a well drilling fluid actuated down hole motor when assembled thereon,
• bearing means in said bearing housing supporting said bearing shaft, in which
• said bearing means comprises at least two radial/thrust bearings, each having one bearing member supported on said housing and another bearing member, having rotary bearing contact therewith, supported on and rotatable with said rotary shaft means,
• said bearing members having initially flat surfaces meeting on a substantially conical surface of contact,
• said bearing members, after break in, having substantially conical bearing surfaces meeting for smooth rotary bearing contact on said conical surface of contact, and
• said conical bearing surfaces each having bearing faces of diamond comprising the only bearing surfaces in said radial/thrust bearing.

A radial/thrust bearing for use in rotary tools comprising

• a first annular supporting plate having an exterior conical end surface,
• a second annular supporting plate having an interior conical end surface of a shape substantially parallel to the exterior conical end surface of said first supporting plate when assembled in bearing relation,
• a plurality of insert members equally spaced around said first annular plate, extending radially thereof and substantially normal to the conical surface thereof and having initially flat diamond bearing surfaces positioned in conical relation,
• a plurality of insert members equally spaced around said second annular plate, extending radially thereof and substantially normal to the conical surface thereof and having initially flat diamond bearing surfaces positioned in conical relation and adapted to fit against said first-named diamond bearing surfaces along a conical surface of contact when assembled in bearing relation,
• said supporting plates being adapted to be secured to relatively rotatable members with said bearing surfaces in rotary bearing contact, and
• said initially flat bearing surfaces being adapted to support radial thrust loads and support longitudinal thrust loads in one direction and to wear into conical bearing surfaces corresponding to said conical surface of contact.