ISO/TR 17606:2014

Plain bearings - Lubrication characteristics of crosshead pin bearings for low-speed marine diesel engines

ISO/TR 17606:2014 specifies lubrication characteristics of grooves and pockets on crosshead pin bearings for low-speed marine diesel engines. It is applicable to the design of axial oil groove and pocket types as an oil supply method.

Paliers lisses — Caractéristiques de lubrification des paliers de crosse pour moteurs diesels marins à vitesse faible

General Information

• Status: Published
• Publication Date: 15-Jun-2014
• ICS: 21.100.10 - Plain bearings
• Technical Committee: ISO/TC 123/SC 7 - Special types of plain bearings
• Drafting Committee: ISO/TC 123/SC 7 - Special types of plain bearings
• Current Stage: 6060 - International Standard published
• Start Date: 16-Jun-2014
• Due Date: 22-Apr-2015
• Completion Date: 22-Apr-2015

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.

Standards Content (Sample)

TECHNICAL ISO/TR
REPORT 17606
First edition
2014-06-15
Plain bearings — Lubrication
characteristics of crosshead pin
bearings for low-speed marine diesel
engines
Paliers lisses — Caractéristiques de lubrification des paliers de crosse
pour moteurs diesels marins à vitesse faible
Reference number
©
ISO 2014
© ISO 2014
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Published in Switzerland
ii © ISO 2014 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Crosshead pin bearing and its symbols . 1
3 Oil supply method on bearing sliding surfaces . 3
4 Shape of a bearing . 3
4.1 Bearing inside diameter, bearing width, height, circumferential groove, and an
upper bearing . 3
4.2 Wall thickness of a bearing and shape of its bore . 4
4.3 Oil supply — Lubrication characteristics . 5
Bibliography . 8
Foreword
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The committee responsible for this document is ISO/TC 123, Plain bearings, Subcommittee SC 7, Special
types of plain bearings.
iv © ISO 2014 – All rights reserved

Introduction
For crosshead pin bearings, with which a shaft oscillates when a load is applied mainly in a downward
direction, it is difficult to generate an appropriate lubricating film; therefore, they are subject to
unfavourable lubricating conditions. For better lubrication of crosshead pin bearings, which have a
high rate of damage, two types of bearing structures are mainly used as oil supply methods for sliding
surfaces at present. The characteristics of those bearings are compared and the concept of design
approaches is standardized.
TECHNICAL REPORT ISO/TR 17606:2014(E)
Plain bearings — Lubrication characteristics of crosshead
pin bearings for low-speed marine diesel engines
1 Scope
This Technical Report specifies lubrication characteristics of grooves and pockets on crosshead pin
bearings for low-speed marine diesel engines.
It is applicable to the design of axial oil groove and pocket types as an oil supply method.
2 Crosshead pin bearing and its symbols
The crosshead pin bearing and changes in specific load and angular velocity during one cycle are
schematically illustrated in Figures 1 and 2. Table 1 shows the symbols and their descriptions.
Figure 1 — Crosshead pin bearing
Figure 2 — Changes in specific load and angular velocity during one cycle
Table 1 — Symbols and their descriptions
Symbol Description
e eccentricity
hmin minimum oil film thickness
l subtended taper length
L axial width
O center of bearing
b
O center of journal
j
p oil film pressure
P1 pad 1
P2 pad 2
P3 pad 3
specific load
P
r
r shaft radius
F bearing load
α circumferential pitch angle
β circumferential width angle
γ taper depth
φ oscillation angle
ϕ attitude angle
θ circumferential angular coordinate
θ2 – θ1 effective angular extent of bearing arc
ω angular velocity
2 © ISO 2014 – All rights reserved
3 Oil supply method on bearing sliding surfaces
There are two oil supply methods. One is for bearings with a few (normally four) axial grooves. Oil is
supplied to the sliding surface at normal pressure through these oil grooves. The other is for bearings
with two oil pockets symmetrically located relative to the central part of each bearing. Oil is supplied to
the oil pockets at high pressure to provide a hydrostatic bearing mechanism (see Figure 3).
Figure 3 — Bearings with axial grooves and oil pockets
4 Shape of a bearing
4.1 Bearing inside diameter, bearing width, height, circumferential groove, and an up-
per bearing
The diameter of a crosshead pin is set by consideration of
...