Cylindrical Roller Bearing Retainer Structure to Prevent Outer Ring Drop-Off
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Solution Overview
Problem
Existing cylindrical roller bearings face increased manufacturing costs and reduced assembly workability due to the need for complex components and machining, particularly in preventing the retainer from falling off and ensuring easy roller insertion and retention.
Innovation Solution
The design features a retainer with protrusion portions on its annular portion and column portions, which engage with the outer ring's inward flange, allowing for secure retention without additional components, and optimized dimensions for roller insertion and prevention of roller fall-off, including specific protrusion amounts and distances relative to the roller diameter.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a guide member is separately provided to prevent the retainer from falling off, then the retainer can be prevented from falling off, but the number of components is increased and manufacturing cost is increased
Solution Approach 1:
The guide member function is merged into the retainer structure itself by forming protrusion portions directly on the retainer's inner circumferential surface. This integration eliminates the need for a separate guide member component while maintaining the retention function, thereby reducing component count and manufacturing cost while preventing retainer fall-off.
2Reliability
If an inclined surface portion is machined on the inner ring to engage the holding tab, then the retainer can be prevented from falling off, but the manufacturing cost is increased
Solution Approach 1:
The engagement structure is merged into the retainer by forming protrusion portions directly on the retainer body. This eliminates the need for separate machining operations on the inner ring and simplifies the overall manufacturing process, reducing manufacturing cost while maintaining reliable retainer retention.
Solution Approach 2:
The design changes from requiring precise machining of inclined surfaces to using molded protrusion portions with specific dimensional parameters (protrusion distance of 0.5 to 2.0 mm). This parameter-based design simplifies manufacturing while achieving the same retention function.
3Device complexity
If the cylindrical rollers directly roll on the outer circumferential surface of the shaft, then the bearing structure is simplified, but the cylindrical rollers may fall off from the retainer during transportation
Solution Approach 1:
The protrusion portions are pre-formed on the retainer structure before assembly. These protrusions create preliminary engagement features that prevent roller fall-off during transportation and assembly operations, while maintaining the simplified direct-rolling bearing structure without requiring additional retention components.
Data Source
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AI summary
In a cylindrical roller bearing (10) with an outer ring, an annular portion (32) on the other side in an axial direction of the retainer (30) is provided with a plurality of protrusion portions (40) each having an engaging portion (41) protruding radially outward with respect to an inner circumferential surface of an inward flange portion (15). Further, when an axial distance between a flat surface on one side in the axial direction of an outward flange portion (14) and an end surface on the one side in the axial direction of the annular portion (31) on the one side in the axial direction is set as A, and an axial distance between a flat surface on the other side in the axial direction of the inward flange portion (15) and a side surface on the one side in the axial direction of the engaging portion (41) is set as B, B is greater than A. Accordingly, it is possible to provide a cylindrical roller bearing with an outer ring which can prevent the retainer from falling off from the outer ring with good assembly workability without increasing the number of components, and which takes into consideration insertion workability of the cylindrical rollers and prevention of the cylindrical rollers from falling off from the retainer.