Overview
ISO 14728-1:2017 - "Rolling bearings - Linear motion rolling bearings - Part 1: Dynamic load ratings and rating life" defines methods for calculating the basic dynamic load rating and basic rating life for contemporary linear motion rolling bearings. The standard applies to bearings manufactured from high‑quality hardened bearing steel and of conventional contact geometry. It also defines life and the conditions required for reliable life calculations. Note: the standard is not applicable where rolling elements operate directly on a machine slide surface unless that surface is fully equivalent to a bearing raceway.
Key topics
- Scope and definitions: clear definitions of life, reliability and basic rating life (life at defined reliability) for linear motion bearings.
- Bearing types covered: recirculating sleeve ball bearings (with/without raceway grooves), recirculating carriage-type guideways, non‑recirculating deep‑groove and four‑point‑contact ball guideways, and non‑recirculating roller guideways (flat, V‑angle, crossed).
- Calculation methods: procedures and formulae for determining the basic dynamic load rating (C) and the dynamic equivalent load (P) for various linear bearing designs.
- Factors and parameters: treatment of pitch diameter, ball/roller diameter and length, number of rows, nominal contact angle, load direction, adjustment and correction factors (e.g., for short‑stroke applications), and dynamic load factors used in rating calculations.
- Symbols and notation: harmonized symbols (references to ISO 281 / ISO 15241) used throughout the calculations and tables.
- Theoretical basis: life calculation approach based on established rolling‑bearing fatigue theories (Lundberg–Palmgren principles).
Applications
ISO 14728-1 is intended for use by professionals who design, select or evaluate linear motion rolling bearings and systems, including:
- Mechanical and design engineers specifying linear guides for CNC machines, robotics, automation systems and material‑handling equipment.
- Bearing manufacturers developing product ratings and catalog data.
- Maintenance and reliability engineers performing bearing life estimates and replacement planning.
- Procurement and quality teams verifying vendor data and conformity to international rating practices.
Practical benefits include consistent life estimates, reliable load‑rating data for system design, and improved interchangeability and performance prediction for linear guide components.
Related standards
- ISO 281 (rolling bearing life calculation principles)
- ISO 5593 (rolling bearing terminology)
- ISO 15241 (symbol and data conventions)
- Other parts of the ISO 14728 series for complementary topics (static load safety factors, etc.)
Keywords: ISO 14728-1:2017, rolling bearings, linear motion rolling bearings, dynamic load rating, basic rating life, linear ball bearings, linear roller bearings, dynamic equivalent load, life calculation.