Drawn Cup Needle Roller Bearing Seal Ring Press Working
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Solution Overview
Problem
Drawn cup needle roller bearings with seal rings face challenges in achieving high dimensional accuracy and controlling lubricant quantity due to limitations in cutting working methods, leading to potential abrasion and torque issues.
Innovation Solution
A drawn cup needle roller bearing with a seal ring formed by press working, avoiding heat treatment, and treated for abrasion resistance, featuring a floating seal design and a resin cage for improved accuracy and reduced manufacturing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the seal ring is made by cutting working, then the manufacturing process is simple, but the dimensional accuracy (circularity of inner diameter and dimensional tolerance) cannot be ensured
Solution Approach 1:
The patent changes the manufacturing method parameter from cutting working to press working (specifically deep drawing process). This parameter change enables the seal ring to achieve high dimensional accuracy with circularity of inner diameter of 0.05mm or less and dimensional tolerance of inner diameter of IT6 or more, while maintaining manufacturing efficiency through a single-step forming process.
2Object-affected harmful factors
If heat treatment is executed after cutting working to prevent abrasion, then abrasion resistance is improved, but the dimensional accuracy deteriorates due to deformation
Solution Approach 1:
The patent applies preliminary action by forming the seal ring with high dimensional accuracy through press working before any heat treatment. The deep drawing process creates the precise circular shape and dimensions first, and only then is heat treatment applied for abrasion resistance. This sequence prevents heat-induced deformation from affecting the critical dimensional accuracy of the seal ring inner diameter.
Solution Approach 2:
The patent changes the material parameter by selecting steel plates with specific properties (thickness 0.3 to 1.5mm, tensile strength 300 to 500MPa, elongation 10 to 20%) that are suitable for press working. This parameter selection enables the material to achieve both high dimensional accuracy during forming and adequate abrasion resistance, eliminating the need for subsequent heat treatment that would cause deformation.
3Length of stationary object
If the seal ring is made thinner to reduce bearing height, then the bearing size is reduced, but the strength and abrasion resistance deteriorate
Solution Approach 1:
The patent changes the geometric parameter of the seal ring thickness to 1.0 to 2.5mm (optimizing the balance between thinness and strength). Combined with the press working method that provides superior dimensional control and the selection of high-strength steel materials, this parameter change enables the seal ring to maintain adequate strength and abrasion resistance even at reduced thickness, thereby reducing the overall bearing height to 1.5 to 2.5mm.
Data Source
AI summary
A method of manufacturing a drawn cup needle roller bearing having a seal ring, including forming the seal ring by a press working by: punching a metal plate to form an annular first intermediate material; subjecting the first intermediate material to burring working such that a portion close to an inner diameter of the first intermediate material is bent in an axial direction at a right angle to form an annular second intermediate material having an L-shaped cross section, the second intermediate material comprising a cylindrical portion and an outward flange portion which is bent radially outward from an axial end portion of the cylindrical portion; removing the outward flange portion to form a cylindrical third intermediate; and subjecting the third intermediate material to cold rolling working to regulate an inner diameter, an outer diameter and a cross sectional shape of the third intermediate material.