PCD Bearing Assembly Grooves to Prevent Brazing Cracks
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Solution Overview
Problem
Current bearing apparatuses using polycrystalline diamond compacts (PDCs) face challenges with cracking during brazing and limited configurability, toughness, and wear resistance, which affect their performance and cost-effectiveness in mechanical applications.
Innovation Solution
The use of PCD bearing elements with specific magnetic properties and grooves on their surfaces, where the first PCD elements exhibit high coercivity and low magnetic saturation, and the second elements have lower coercivity and higher magnetic saturation, are mounted on support rings, with grooves on the first elements to manage cracking and improve cooling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If PCD bearing elements are brazed directly into support rings, then bearing assemblies can be manufactured, but cracking occurs during brazing and toughness is reduced
Solution Approach 1:
Grooves are formed in the PCD bearing elements before the brazing process. This preliminary action creates stress relief features that prevent cracking during subsequent brazing operations, thereby maintaining toughness while enabling manufacturing.
Solution Approach 2:
The PCD bearing element surface is segmented into multiple regions by forming grooves. This segmentation allows stress to be distributed and managed, preventing crack propagation during brazing while maintaining the overall structural integrity and toughness of the bearing element.
2Strength
If PCD bearing elements are made with high coercivity and low magnetic saturation, then wear resistance and toughness are enhanced, but manufacturing complexity increases
Solution Approach 1:
The magnetic properties of PCD bearing elements are controlled by adjusting HPHT process parameters (pressure, temperature, catalyst composition). By changing these processing parameters, the desired high coercivity and low magnetic saturation properties are achieved, enhancing wear resistance and toughness without requiring additional manufacturing steps.
3Reliability
If grooves are formed on PCD bearing element surfaces, then cracking is reduced and cooling is improved, but manufacturing steps increase
Solution Approach 1:
The groove formation process is combined with the existing PCD manufacturing process by forming grooves during or after the HPHT sintering process. This merging of operations achieves crack resistance and improved cooling without adding significant manufacturing complexity, as the grooves are created using processes already integrated into PCD production.
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
This configuration reduces cracking, enhances toughness and wear resistance, and allows for more cost-effective and customizable bearing assemblies with improved performance in applications like subterranean drilling and motor systems.
Implementation Method 1
a specific magnetic saturation of about 14 G·cm³/g or less
Implementation Method 2
a coercivity of about 125 Oe or more
Data Source
Figure 1A
Figure 1B~1C
Figure 2A
AI summary
Bearing assemblies that include a plurality of polycrystalline diamond ("PCD") bearing elements, bearing apparatuses including such bearing assemblies, and methods of operating and fabricating such bearing assemblies and apparatuses are disclosed. In an embodiment, the plurality of PCD bearing elements of one or more of the bearing assemblies disclosed herein include at least one first PCD bearing element. At least a portion of the first PCD bearing element exhibits a coercivity of about 125 Oersteds or more and a specific magnetic saturation of about 14 Gauss·cm3/gram or less. The first PCD bearing element includes a bearing surface with at least one groove formed therein. In an embodiment, the plurality of PCD bearing elements also include at least one second PCD bearing element. The second PCD bearing element exhibits a coercivity that is less than and a specific magnetic saturation that is greater than the first PCD bearing element.