Superhard Bearing Elements in Downhole Motors

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Solution Overview

Problem

Subterranean drilling systems face challenges with wear resistance and efficiency due to repetitive contact between diamond bearing elements in thrust-bearing apparatuses, leading to reduced operational lifetime and increased frictional losses.

Innovation Solution

Hydrodynamic bearing assemblies with superhard bearing surfaces and sealant materials are employed in downhole motors, forming a fluid film to reduce contact and enhance wear resistance and efficiency, utilizing superhard materials like polycrystalline diamond and tungsten carbide, and incorporating sealant materials to prevent fluid leakage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If diamond bearing elements are used in thrust-bearing apparatuses, then wear resistance is improved, but frictional losses increase due to repetitive contact

Engineering Contradiction:

Improvewear resistanceVSAvoidfrictional losses

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

A fluid film (intermediary substance) is introduced between the diamond bearing elements to mediate the contact interaction. This fluid film acts as a mediator that reduces direct solid-to-solid contact, thereby decreasing frictional losses while allowing the diamond elements to maintain their wear-resistant properties. The fluid film absorbs and distributes the contact stresses, preventing direct friction between bearing surfaces.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent employs hydraulic principles by utilizing a fluid (drilling fluid or lubricant) to create a hydrodynamic bearing film between the bearing elements. The fluid pressure and flow characteristics are harnessed to maintain separation between contacting surfaces, converting a dry friction problem into a fluid-film lubrication problem, thereby reducing energy losses while preserving wear resistance.

Inventive Principle:

Principle #29Pneumatics and hydraulics

2Force

If diamond bearing elements are used in thrust-bearing apparatuses, then load-bearing capacity is improved, but operational lifetime is reduced due to wear from repetitive contact

Engineering Contradiction:

Improveload-bearing capacityVSAvoidoperational lifetime

Core Design Contradiction:

ForceVSDuration of action of moving object

Solution Approach 1:

The fluid film serves as an intermediary that protects the diamond bearing elements from direct repetitive contact. By introducing this protective layer, the bearing elements can sustain high loads through fluid pressure distribution while the fluid film absorbs the wear that would otherwise occur at the solid contact interfaces, thereby extending operational lifetime without compromising load-bearing capacity.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the direct mechanical contact system with a fluid-film-based support system. Instead of relying solely on solid-to-solid contact to bear loads, the system substitutes part of the load-bearing function to the fluid film, which can sustain loads through hydrodynamic pressure while reducing mechanical wear on the bearing elements.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Quantity of substance

If sealant materials are added to prevent fluid leakage, then fluid retention is improved, but device complexity increases

Engineering Contradiction:

Improvefluid retentionVSAvoidstructure complexity

Core Design Contradiction:

Quantity of substanceVSDevice complexity

Solution Approach 1:

The patent employs thin film sealant materials to create effective fluid barriers within the bearing apparatus. These thin films provide adequate fluid retention while occupying minimal space and adding minimal structural complexity. The flexible nature of thin film seals allows them to conform to bearing surfaces and maintain sealing effectiveness without requiring complex rigid sealing structures.

Inventive Principle:

Principle #30Flexible shells and thin films

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The hydrodynamic bearing assemblies significantly reduce wear and friction, extending the operational lifetime of subterranean drilling systems by minimizing contact between bearing elements and maintaining efficiency through a fluid film, even under high thrust loads and varying operational conditions.

Implementation Method 1

Methodology Applied

Scientific EffectHydrodynamic lubrication: Lubrication

Data Source

PatentUS9347484B2Bearing apparatus having superhard bearing elements

Publication Date: 2016.05.24 US SYNTHETIC CORP

AI summary

Bearing assemblies and apparatuses are disclosed. Such bearing assemblies may be employed in bearing apparatuses for use in downhole motors of a subterranean drilling system or other mechanical systems. In an embodiment of the present invention, a bearing apparatus includes a first bearing assembly including a first substantially continuous polycrystalline diamond bearing surface defining an annular surface, and a second bearing assembly including a second substantially continuous polycrystalline diamond bearing surface defining an annular surface. The second substantially continuous polycrystalline diamond bearing surface generally opposes the first substantially continuous polycrystalline diamond bearing surface.