Overview
SIST ISO 9628:2020 - Rolling bearings: Insert bearings and eccentric locking collars - Geometrical product specifications (GPS) and tolerance values defines the dimensional and geometrical characteristics, boundary dimensions, tolerance values and radial internal clearances for insert bearings and eccentric locking collars. This third edition (2019) updates the 2006 version, applies the ISO GPS system, and adds diameter series 3 and tightened interchangeability controls.
Key phrases: SIST ISO 9628:2020, rolling bearings, insert bearings, eccentric locking collars, geometrical product specifications, GPS, tolerances, radial internal clearance.
Key topics and technical requirements
- Scope: Specifies boundary dimensions, geometrical characteristics and tolerance rules for insert bearings and eccentric locking collars, and radial internal clearances of insert bearings.
- Geometrical product specification (GPS) approach: Applies ISO GPS fundamentals (ISO 8015) and dimensional tolerancing rules (ISO 14405-1); links functional requirements to measurement technique and uncertainty.
- Dimensional characteristics covered:
- Bore diameter (inner ring and eccentric collar) - tolerancing convention allows plus-side bore tolerances for slip-on assembly to standard shafts.
- Outside diameter - aligned with ISO 15 diameter series 2 or series 3 depending on metric bore.
- Inner- and outer-ring widths, overall width (including locking device), location relative to outer ring middle plane.
- Eccentric features - eccentricity, eccentric extension dimensions, chamfers and fillet radii for inner ring and eccentric collars.
- Boundary dimensions and tolerances: Defines symbols, nominal/limit sizes and tolerance zones for drawing and product documentation; introduces tolerance on spherical outside diameter (D) to improve interchangeability among manufacturers.
- Radial internal clearances: Specifies clearance classes and rules for internal clearance measurement and documentation.
- Illustrative figures: Multiple schematic figures show bearing variants (eccentric collars, concentric collars, set-screw locking) and dimensional references.
Practical applications
- Ensures interchangeability and consistent fit for insert bearings used in housings with spherical seatings to accommodate misalignment.
- Guides design engineers specifying bearing envelope, shaft fits and locking device geometry.
- Supports manufacturers for production tolerances, inspection criteria and product data sheets.
- Assists quality/inspection teams in applying GPS measurement rules and uncertainty considerations for acceptance testing.
- Useful for OEMs, machine builders and maintenance engineers specifying replacement bearings and ensuring compatibility with standard shafts and housings.
Who should use SIST ISO 9628:2020
- Bearing manufacturers and suppliers
- Mechanical and design engineers (power transmission, agricultural, HVAC, industrial machinery)
- Quality assurance and metrology teams
- Standards writers and procurement specialists
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