Standards Development

Scope

This document specifies test and assessment methods for cleanliness of rolling bearings and bearing parts.

This document is applicable to the test and assessment for various types of open bearings and capped bearings before grease filling, as well as the test and assessment of bearing parts.

Purpose

The cleanliness of a bearing has a direct influence on its vibration,noise and life reliability. Therefore, controlling bearing cleanliness to a certain level is necessary.The various test and assessment methods of bearing cleanliness directly result in the differences of test and assessment results. Therefore, standardization of test and assessment methods of bearing cleanliness is indispensable for the manufacture of contemporary bearings.

There are some existing international standards specifying cleanliness test method in the field of road vehicles and hydraulic fluid power ,such as ISO 16232:2018 "Road vehicles—Cleanliness of components and systems" and ISO 4407:2002 "Hydraulic fluid power—Fluid contamination— Determination of particulate contamination by the counting method using an optical microscope". However, the test and assessment methods in these standards can not be applied to bearings directly, since bearings are high-precision products with specific technical requirements.

The purpose of the proposed document is to standardize test and assessment methods for bearing cleanliness. Test methods specify the procedures for gravimetric method and particle-counting method, and assessment methods specify the sampling methods for gravimetric method and particle-counting method, as well as the cleanliness limits for gravimetric method. Using standardized test and assessment methods can ensure comparability of the results.

The preparation of the proposed document is feasible. It is based on experience of many years of practice in China, such as a Chinese national standard GB/T 336242017 “Rolling bearingsTest and assessment methods for cleanliness” and its previous editions (the earliest edition is ZQ 1185 ,which only specifies the gravimetric method).