Thrust Roller Bearing Cage Press-Flattened Projections
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Solution Overview
Problem
Existing thrust roller bearing cages face challenges in reducing running torque and maintaining strength, especially when housing small-diameter short rollers, as the formation of projecting portions can lead to lubricant film discontinuity and reduced cage strength.
Innovation Solution
The thrust roller bearing cage employs a press-flattening process for the projections that contact the rollers, combined with engagement portions for accurate alignment, to mitigate lubricant film discontinuity and enhance the lubricating properties, thereby reducing running torque and improving cage performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If projecting portions are formed on the inner walls of pockets to pivotally support rollers, then the running torque is reduced and wear resistance is improved, but the cage strength is significantly reduced when housing small-diameter short rollers
Solution Approach 1:
The invention applies different structural characteristics to different parts of the cage. The radially outer area where projections are formed has localized bending and press-flattening to create contact surfaces, while the rest of the cage maintains its original strength. This local modification approach reduces running torque through proper roller contact without significantly compromising overall cage strength.
Solution Approach 2:
The radially outer area of the cage material is bent inwardly along the radius before the final assembly. This preliminary bending action prepares the structure to receive and properly contact the rollers, ensuring optimal positioning and reducing running torque from the outset while maintaining structural integrity.
2Manufacturing precision
If the plate thickness of the cage is made thinner to achieve proper contact between roller end faces and projecting portions, then the contact is improved, but the strength of the cage is significantly reduced
Solution Approach 1:
Instead of changing the plate thickness parameter, the invention changes the geometric configuration by bending the radially outer area inwardly and applying press-flattening to create properly positioned contact surfaces. This parameter transformation approach achieves precise roller contact while maintaining the original plate thickness and associated strength.
3Ease of manufacture
If projecting portions are formed at improper positions, then the manufacturing is simplified, but proper contact between projecting portions and roller end faces cannot be achieved
Solution Approach 1:
The invention adds a radial dimension to the projection formation by bending the radially outer area inwardly along the radius. This dimensional approach allows projections to be formed at proper positions relative to the rollers, achieving both manufacturing simplicity and contact position accuracy through the bending and press-flattening process.
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 solution effectively reduces running torque and enhances the performance of the thrust roller bearing cage by ensuring proper contact between the rollers and projections, while maintaining the cage's strength, even with small-diameter rollers.
Implementation Method 1
The projections have areas in use that make contact with the end faces of the rollers, the areas being subjected to a press-flattening process
Implementation Method 2
after bending a radially outer area of the cage material inwardly along a radius
Implementation Method 3
the chances of oil/lubricant film discontinuity caused by sliding motion of the end faces of the rollers on the contact areas of the projections
Data Source
Figure 1~2
Figure 3~4(F)
Figure 5~7
AI summary
A thrust roller bearing cage (11) is a cage (11) provided to a thrust roller bearing and having a plurality of pockets (21) that house needle rollers (13). The cage (11) includes projections (44) that are formed by bending a radially outer area of the cage (11) inwardly along the radius and that project inwardly along the radius toward a radially outer area of the pockets (21) to make contact with end faces (16) of the rollers (13). The projections (44) have corners (45) that make contact with the end faces (16) of the rollers (13). The corners (45) are press-flattened.