Ceramic Ball Surface Processing for Belt-Like Portion Removal
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing materials for ceramic balls used in bearings face challenges in achieving high polishing efficiency while maintaining excellent durability, particularly due to the presence of a belt-like portion which hinders further enhancement of polishing efficiency and results in poor durability under heavy loads.
Innovation Solution
A material for a ceramic ball is developed with a sphericity of 2% or less and an arithmetic mean roughness Ra of 0.2 μm or more and 2 μm or less, characterized by the removal of the belt-like portion and processed using a device that ensures precise removal and control of the sphericity and surface roughness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a material for a ceramic ball is produced by die pressing with a belt-like portion, then the formed body structure is simplified, but the polishing efficiency is reduced and durability is poor
Solution Approach 1:
The invention removes the belt-like portion from the ceramic formed body through a dedicated processing step. The processing device includes a processing portion that contacts and removes the belt-like portion, transforming the formed body into a spherical shape suitable for polishing. This extraction of the harmful belt-like structure directly improves polishing efficiency while maintaining ease of manufacture through the systematic processing approach.
2Productivity
If tumbling granulation is used to produce material for ceramic balls, then polishing efficiency is enhanced due to absence of belt-like portion, but the formed body is poorly-densified and durability is reduced
Solution Approach 1:
The invention changes the densification parameter by applying high pressing pressure (500 MPa or more) in the die pressing step. This high pressure ensures proper densification of the ceramic formed body, creating a dense structure that maintains durability. The processing device then removes the belt-like portion from this densely pressed formed body, achieving both high polishing efficiency and excellent durability through the combination of high pressure densification and belt-like portion removal.
3Ease of manufacture
If the belt-like portion is present in the material for a ceramic ball, then the formed body can be easily produced by die pressing, but the arithmetic mean roughness is increased and polishing efficiency is hindered
Solution Approach 1:
The invention performs preliminary removal of the belt-like portion before the final polishing step. The processing device contacts and removes the belt-like portion from the die-pressed formed body, preparing a smooth spherical surface that is ready for subsequent polishing. This preliminary action eliminates the source of surface roughness created by the belt-like portion, enabling achievement of the required Ra ≤ 0.013 μm surface finish.
Data Source
AI summary
In a material for a ceramic ball according to an embodiment, a sphericity is 2% or less, and an arithmetic mean roughness Ra is 0.2 μm or more and 2 μm or less. In the material for the ceramic ball, a total height of profile Rt is preferably 4 μm or more and 20 μm or less. In the material for the ceramic ball, when a surface roughness Ra in a circumferential direction of a belt-like portion mark is defined as Ra1, and a surface roughness Ra of a circumference in a direction perpendicular to the belt-like portion mark is defined as Ra2, Ra1/Ra2 is preferably 0.2 or more and 2 or less.