Overview
SIST ISO 246:2008 is an international standard published by the International Organization for Standardization (ISO) that defines the boundary dimensions for separate thrust collars used with cylindrical roller bearings. Specifically, it covers the width, maximum outside diameter, bore diameter, and bore minimum chamfer of thrust collars designed for cylindrical roller bearings within diameter series 0, 2, 3, and 4, as outlined in the related ISO 15 standard.
This standard excludes specifications for overall width and internal geometrical features that vary depending on the bearing’s internal design. SIST ISO 246:2008 helps ensure interchangeability, compatibility, and consistency in the manufacturing and application of thrust collars in rolling bearing assemblies.
Key Topics
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Scope and Applicability
SIST ISO 246:2008 applies to separate thrust collars for cylindrical roller bearings in multiple diameter series (0, 2, 3, 4) including standard and reinforced (E-design) types. It standardizes key dimensions critical for bearing fit and function.
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Boundary Dimension Specifications
The standard details dimensions such as:
- Width (B) of thrust collar protruding beyond the inner ring face
- Maximum outside diameter (dₐ)
- Bore diameter (d)
- Minimum chamfer dimension (r₁s min) at the bore
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Diameter Series and Design Variations
The standard covers different diameter series with corresponding dimension tables, addressing both standard and enhanced load-bearing designs (2E and 3E series) characterized by reinforced roller and cage assemblies.
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Normative References
SIST ISO 246:2008 references other crucial standards, reinforcing consistency:
- ISO 15 (Rolling bearings-Radial bearings boundary dimensions)
- ISO 582 (Chamfer dimensions - maximum values)
- ISO 5593 (Rolling bearings vocabulary)
- ISO 15241 (Symbols for quantities in rolling bearings)
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Technical Symbols and Definitions
Symbols such as B (thrust collar width), d (bore diameter), and r (chamfer) are used consistently to communicate dimensional values clearly.
Applications
SIST ISO 246:2008 is essential for manufacturers, engineers, and designers involved with rolling element bearing assemblies, particularly where separate thrust collars are implemented. Its standardization facilitates:
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Bearing Assembly Design
Ensuring that thrust collars conform to prescribed dimensions guarantees correct assembly fit, optimal bearing performance, and reduced risk of premature wear or failure.
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Quality Control and Inspection
Provides measurable, defined dimensions for acceptance criteria in production and quality assurance processes within bearing manufacturing.
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Interchangeability and Compatibility
Standardized dimensions enable bearings and thrust collars from different manufacturers to be compatible, simplifying maintenance, repairs, and replacement operations.
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Mechanical Equipment Reliability
Used across industries such as automotive, aerospace, industrial machinery, and heavy equipment to ensure reliability of machines relying on cylindrical roller bearings.
Related Standards
When working with SIST ISO 246:2008, the following standards are directly relevant:
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ISO 15: Rolling Bearings - Radial Bearings - Boundary Dimensions, General Plan
Defines general boundary dimensions and diameter series classifications for radial bearings, forming the basis for ISO 246 dimensional references.
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ISO 582: Rolling Bearings - Chamfer Dimensions - Maximum Values
Specifies chamfer sizes for bearing components, ensuring standardization of edges to prevent stress concentrations and ease installation.
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ISO 5593: Rolling Bearings - Vocabulary
Provides terminology used consistently for clear communication in the rolling bearing industry.
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ISO 15241: Rolling Bearings - Symbols for Quantities
Defines symbols used universally in documentation and technical drawings related to rolling bearings.
By adhering to the specifications of SIST ISO 246:2008, professionals can achieve consistent performance, durability, and reliability in cylindrical roller bearing assemblies employing separate thrust collars, thereby optimizing the mechanical integrity of rotating machinery worldwide.
