Outer-Ring Guide Angular Ball Bearing for Cage Noise Reduction
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Solution Overview
Problem
Angular contact ball bearings with outer ring guide cages experience self-vibration and noise due to shape errors and misalignment between the inner and outer ring raceway surfaces, leading to frictional forces that cause cage noise.
Innovation Solution
The design includes an outer ring guide cage with annular and pillar portions, where the cage inner diameter is uniform, and specific geometric relationships between the cage inner diameter, radial guide clearance, and ball pitch circle diameter are maintained to ensure stable rotational operation and reduce frictional forces, thereby minimizing cage noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If an outer ring guide cage is used for high-speed rotation, then good lubricity is achieved by lubricant flowing radially outward, but cage self-vibration and cage noise occur due to contact between pocket inner surface and balls
Solution Approach 1:
A resin layer is introduced as an intermediary substance between the cage pocket inner surface and the balls. This resin layer acts as a mediator that reduces direct contact and friction, thereby suppressing cage self-vibration and cage noise while allowing the cage to function properly at high rotation speeds with good lubricity
Solution Approach 2:
The friction characteristics between the cage and balls are changed by applying a resin coating to the pocket inner surface. This parameter change in surface properties reduces the coefficient of friction and prevents direct metal-to-metal or rigid structure contact, eliminating the source of cage noise while maintaining operational speed
2Reliability
If shape errors or misalignment occur between inner and outer ring raceway surfaces, then balls contact pocket inner surfaces with delay or advance, but this causes frictional force and cage self-vibration
Solution Approach 1:
The resin layer serves as a compliant intermediary that absorbs and compensates for timing variations in ball contact caused by shape errors or misalignment. This intermediary layer prevents direct transmission of impact forces to the cage structure, maintaining cage stability while allowing the bearing to operate reliably
Solution Approach 2:
The resin coating on the pocket inner surface provides beforehand cushioning for potential impact forces from balls contacting with timing delays or advances. This pre-applied cushioning layer prevents direct hard contact and reduces frictional forces that would otherwise cause cage self-vibration
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 stabilizes the rotational movement of the cage and significantly reduces cage noise by ensuring that the contact position remains at the equator portion of the ball, even during radial movement, and restricts excessive vibration, enhancing the operational stability and noise reduction.
Implementation Method 1
the outer ring guide cage having good lubricity by a lubricant flowing to a radially outer side by a centrifugal force
Data Source
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AI summary
A cage (14) includes: a pair of ring parts (15, 16); and a plurality of pillar parts (17) that couple the pair of ring parts (15, 16) in the axial direction and that are disposed at predetermined intervals in the circumferential direction. An inner-diameter-side opening section (21) of a pocket (20) has a cage inner diameter that is equal over the entire circumference of the pocket (20) and satisfies B+ΔL/2>PCD/2 and PCD/2>A+ΔL/2, where B indicates 1/2 of the cage inner diameter in the inner-diameter-side opening section (21), ΔL indicates a diameter clearance of a radial guide clearance of the cage (14), PCD indicates a pitch circle diameter of balls (13), Dp indicates the diameter of the inner-diameter-side opening section (21) of the pocket (20), A=Bcosθ, and θ=sin-1{(Dp/2)/B}. Accordingly, an angular ball bearing including an outer-ring-guide-type cage that is capable of suppressing cage sound is provided.