Bearing Ring Seal Fastening Layout to Prevent Raceway Stress Cracks
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Solution Overview
Problem
Self-aligning roller bearings face limitations in load-bearing strength due to the small distance between the seal fastening screw bore and the raceway, leading to stress cracks during heat treatment and reduced durability.
Innovation Solution
The bearing ring design includes an annular sealing disc connected to one of the end surfaces, with fastening means having a shank and a head with an enlarged diameter, and bores with a converging profile, ensuring uniform stress distribution and increased load-bearing strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the seal fastening screw bore is positioned close to the raceway to reduce installation space, then the bearing ring size is reduced, but the load-bearing strength decreases and stress cracks occur during heat treatment
Solution Approach 1:
The bore center axis is positioned asymmetrically relative to the raceway, specifically at a distance of 0.5 to 2 times the bore diameter from the raceway. This asymmetric positioning optimizes the stress distribution during induction hardening, preventing stress cracks while maintaining compact bearing dimensions. The asymmetric bore arrangement allows uniform heat treatment without compromising load-bearing strength.
Solution Approach 2:
The patent specifies precise parameter ranges for bore positioning (0.5 to 2 times the bore diameter from the raceway) and bore dimensions (10 to 20 mm diameter). By optimizing these parameters, the design achieves a balance between compact size and sufficient load-bearing strength, eliminating stress cracks during heat treatment while maintaining reduced installation space.
2Volume of moving object
If the bore center axis is positioned asymmetrically relative to the raceway, then the bearing ring can be compact, but stress cracks occur during induction hardening cooling process
Solution Approach 1:
The patent defines optimal parameter ranges for bore positioning (0.5 to 2 times the bore diameter from the raceway) that prevent stress cracks during induction hardening. By carefully controlling these parameters, the design achieves both compact dimensions and reliability free from stress cracks during the cooling process.
Solution Approach 2:
The asymmetric bore positioning is designed in advance to counteract the thermal stresses that will occur during induction hardening. The pre-planned bore arrangement prevents stress crack formation during the cooling process by ensuring uniform stress distribution, thereby eliminating the harmful effect before it can manifest.
3Strength
If stronger bearing rings are used to prevent stress cracks, then load-bearing strength is improved, but material consumption and installation space increase
Solution Approach 1:
Instead of increasing material strength, the patent optimizes the geometric parameters of bore positioning (0.5 to 2 times the bore diameter from the raceway). This parameter optimization achieves sufficient load-bearing strength and stress crack prevention without requiring stronger materials or larger bearing ring dimensions, thereby maintaining compact installation space.
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 design enhances the load-bearing strength and reduces the tendency for stress cracks, allowing for more uniform cooling during hardening and improved durability of the self-aligning roller bearings.
Implementation Method 1
the bore center axis of each bore in the bearing ring and in the sealing disc has an engaged profile which converges onto the cylindrical contour of the one annular surface... ensuring uniform stress distribution and increased load-bearing strength
Implementation Method 2
during induction hardening, can lead to stress cracks during the cooling process
Implementation Method 3
stress cracks during the cooling process
Data Source
AI summary
A bearing, in particular to a self-aligning roller bearing, with a fastener of a sealing disc, which fastener increases the load-bearing strength. The bearing includes a bearing ring with an annular sealing disc which is connected to one of the two bearing ring end surfaces by a fastener which have a shank and a head, which has an enlarged diameter with respect to the shank, and the respective shanks reach through the bores which are made in the respective end surface. Here, the annular surfaces have a cylindrical contour, with the result that the other annular surface provides a raceway, wherein the raceway has a spherical contour, and the bore center axis of each bore in the bearing ring and in the sealing disc has an engaged profile which converges onto the cylindrical contour of the one annular surface.