Overview
ISO/TR 17606:2014 provides guidance on the lubrication characteristics of crosshead pin bearings used in low-speed marine diesel engines. The Technical Report focuses on oil supply methods and the design implications of axial oil grooves and oil pockets on bearing sliding surfaces. It is intended to standardize design approaches that improve oil film formation and bearing life under the challenging, oscillatory loading typical of crosshead pin applications.
Key topics
- Scope and intent
- Specifies lubrication characteristics for grooves and pockets on crosshead pin bearings.
- Applicable to design of axial oil groove and pocket types as oil supply methods.
- Oil supply methods
- Axial oil grooves: typically a few grooves (normally four) that deliver oil at system pressure to the sliding surface.
- Oil pockets: two symmetric pockets fed at high pressure to create a hydrostatic effect and recover oil film near bottom dead centre.
- Bearing geometry and fit
- Bearing inside diameter, width, height and wall thickness considerations tied to strength, clearance and interference fit.
- Clearance ratio (radial clearance divided by bearing radius) strongly influences oil film behaviour - improving wedge effect up to a clearance ratio around 0.0005, but excessive clearance concentrates load and worsens lubrication.
- Lubrication behavior and design guidance
- Oil groove pitch angle (α) should be smaller than the crosshead pin oscillation angle (φ) for axial-grooved bearings to ensure film formation.
- Standard groove cross-section is semicircular; chamfers or tapered ends (bleed grooves) can help supply oil axially and cool sliding surfaces.
- Tapered groove ends improve the wedge effect and increase minimum oil film thickness when clearances are low.
- Hydrostatic pockets increase load capability but require high-pressure supply and careful selection of pocket axial length (L), circumferential width (β) and pitch angle (α).
Applications and users
- Who uses ISO/TR 17606:
- Marine engine designers and mechanical engineers
- Plain bearing manufacturers and tribology specialists
- Shipbuilders, maintenance engineers and classification societies
- Researchers optimizing oil film performance in slow-speed, heavily loaded bearings
- Practical value:
- Improves design choices for oil grooves and pockets to reduce bearing damage and extend service life
- Helps balance manufacturing cost (e.g., hydrostatic supply complexity) against improved load capacity
Related standards
- ISO 4381 - Tin casting alloys for multilayer plain bearings
- ISO 4383 - Multilayer materials for thin-walled plain bearings
- Developed under ISO/TC 123 (Plain bearings), SC 7 (Special types)
Keywords: ISO/TR 17606, crosshead pin bearings, low-speed marine diesel engines, axial oil grooves, oil pockets, lubrication characteristics, hydrostatic bearing, oil film thickness, clearance ratio.