Asymmetrical Cage Angular Ball Bearing for Noise Reduction
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Solution Overview
Problem
Resin-made angular ball bearings experience increased force between the cage and rolling elements and rings, leading to slippage, instability, noise, vibration, and temperature rises due to the spherical shape of pockets and radial positioning of diameters, which existing technologies have not adequately addressed.
Innovation Solution
An angular ball bearing design with an asymmetrical cage and specific angle of contact between 30° and 45°, where the cage is positioned between the inner and outer ring raceway surfaces, and the rolling elements are annularly arranged with pockets that satisfy the relationships 0.62≤2DaD-d≤0.8, A/Da≤0.020, and 2A/PCD≤0.010, to control clearance and prevent abnormal noise, vibration, and temperature rises.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the cage is positioned radially away from the pitch diameter with spherical pockets, then the cage structure is simple and easy to manufacture, but the force between the cage and rolling elements increases causing slippage and instability
Solution Approach 1:
The cage is designed with asymmetrical pocket positioning relative to the pitch diameter, where the cage inner diameter is positioned at a distance A from the pitch diameter rather than radially away. This asymmetrical arrangement reduces the dragging force on the cage while maintaining structural simplicity, thereby improving both manufacturability and reliability.
2Force
If the angle of contact is increased to enhance load-carrying capacity, then the load capability improves, but the cage experiences greater drag force and slippage
Solution Approach 1:
The angle of contact is optimized within a specific range (30°≤α≤45°) to balance load-carrying capacity and cage stability. Additionally, the cage position parameter A is controlled within specific ranges (A/Da≤0.020 and 2A/PCD≤0.010) to minimize dragging force while maintaining the beneficial effects of the contact angle, thus resolving the contradiction between force capability and reliability.
3Use of energy by moving object
If grease lubrication is used to reduce friction, then lubrication effectiveness improves, but resistance during rotation increases causing temperature rise and noise
Solution Approach 1:
By optimizing the cage position parameter A and the angle of contact α, the design reduces slippage and improves rolling element stability. This minimizes unnecessary friction and energy loss, allowing grease lubrication to be more effective without causing excessive temperature rise or noise, thus resolving the contradiction between lubrication effectiveness and harmful factors.
Data Source
AI summary
A cage is asymmetrical to a radially extending straight line extending. Supposing that α is the angle of contact of the rolling element, α is defined as 30°≤α≤45°. The relationship defined in the numerical expression is satisfied, where D is the outer diameter of the outer ring, d is the inner diameter of the inner ring, and Da is the diameter of the rolling element. With center axes of the whole bearing in an axial direction and of the cage in the axial direction overlapping each other, at least one of the following relationships is satisfied;A/Da≤0.020 (2), and2A/PCD≤0.010 (3),where A is the smallest dimension value of a clearance in a radial direction between surfaces of a pocket of the cage facing the rolling element and of this rolling element, and PCD is the pitch diameter of each rolling element.