ICS 21.120.40                         MED 28

Reaffirmed 2019

NATIONAL FOREWORD

This Indian Standard (Part 23) which is identical with ISO 21940-23 : 2012 ‘Mechanical vibration - Rotor balancing - Part 23: Enclosures and other protective measures for the measuring station of balancing machines’ issued by the International Organization for Standardization (ISO) was adopted by the Bureau of Indian Standards on the recommendation of the Mechanical Vibration and Shock Sectional Committee and approval of the Mechanical Engineering Division Council.

This standard supersedes IS/ISO 7475 : 2002 ‘Mechanical vibration - Rotor Balancing Part 23 Enclosures and Other Protective Measures for the Measuring Station of Balancing Machines’.After publication of this standard, IS/ISO 7475 : 2002 shall be treated as withdrawn.

Special purpose balancing machines for examplethose used in the mass production automotive industry, normally incorporated all necessary protective measures because the work piece, as well as the operating conditions of the machines, are known and can be taken into account by the machine manufacturer. For the multipurpose balancing machines, however, where the work piece to be balanced are generally unknown to the machine manufacturer, and are thus beyond his control, basic protective measures are limited to obvious hazards for examplefrom end drive or belt drive systems. However the balancing machine manufacturer has to provide sufficient information for the user to assess possible hazards originating from the rotor when in the balancing machine and from the intended use of the balancing machine. Together with this information the user of the balancing machine has to state the possible hazards origination in his rotors in order to allow the balancing machine manufacturer to supply equivalent protective measures on his own.

When the rotors are not known in advance for example in service and repair, a good estimation is needed. Table A.2 states typical values for different balancing machine sizes. But for each individual type of rotor to be balanced, the user of balancing machine needs to check if the protective measures cover all hazards.

Under the general title ‘Mechanical vibration - Rotor balancing’, the standard is in ten parts, other parts areas following:

Part 1 Introduction

Part 2 Vocabulary

Part 11 Procedures and tolerances for rotors with the rigid behaviour

Part 12 Procedures and tolerances for rotors with flexible behaviour

Part 13 Criteria and safeguards for the in-situ balancing of medium and large rotors

Part 14 Procedures for assessing balance errors

Part 21 Description and evaluation of balancing machines

Part 31 Susceptibility and sensitivity of machines to unbalance

Part 32 Shaft and fitment key convection

The text of ISO Standard has been approved as suitable for publication as an Indian Standard without deviations. Certain conventions are however not identical to those used in Indian Standards. Attention is particularly drawn to the following:

a) Wherever the words ‘International Standard’ appear referring to this standard, they should be read as ‘Indian Standard’.

b) Comma (,) has been used as a decimal marker while in Indian Standards, the current practice is to use a point (.) as the decimal marker.