Standard No.:	GB/T 43617.1-2024
English Name:	Rolling bearings—Noise testing of rolling bearing greases—Part 1: Basic principles, testing assembly and test machine
Chinese Name:	滚动轴承 滚动轴承润滑脂噪声测试 第1部分：基本原则、测试组件和测试仪
Chinese Classification:	J11    Rolling bearing
Professional Classification:	GB    National Standard
ICS Classification:	21.100.20 21.100.20    Rolling bearings 21.100.20
Issued by:	SAMR; SAC
Issued on:	2024-7-1
Implemented on:	2024-3-15
Status:	valid
Language:	English
File Format:	PDF
Word Count:	8000 words
Price(USD):	240.0
Delivery:	via email in 1~3 business day

GB/T 43617.1-2024 Rolling bearings - Noise testing of rolling bearing greases - Part 1: Basic principles, testing assembly and test machine 1 Scope This document specifies: ——basic principles, testing assembly and the test machine for noise testing of rolling bearing greases; ——symbols used in the test methods BQ+, MQ and NQ. This document is applicable for testing rolling bearing greases, especially of unused grease. Note: Suitable greases are greases of NLGI classes 1 to 3 according to DIN 518181) . Suitable greases for lubrication of rolling bearings are especially greases according to ISO 12924. The test method according to this document delivers meaningful results for rolling bearings; however, it can also be applied for greases in similar applications[15,16]. 2 Normative references The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 492 Rolling bearings - Radial bearings - Geometrical product specifications (GPS) and tolerance values Note: GB/T 307.1-2017, Rolling bearings - Radial bearings - Geometrical product specifications (GPS) and tolerance values (ISO 492:2014, IDT) ISO 5593 Rolling bearings - Vocabulary Note: GB/T 6930-2002, Rolling bearings - Vocabulary (ISO 5593:1997, IDT) ISO 5753-1 Rolling bearings - Internal clearance - Part 1: Radial internal clearance for radial bearings Note: GB/T 4604.1-2012, Rolling bearings - Internal clearance - Part 1: Radial internal clearance for radial bearings (ISO 5753-1:2009, IDT) ISO 15242-1 Rolling bearings - Measuring methods for vibration - Part 1: Fundamentals Note: GB/T 24610.1-2019, Rolling bearings - Measuring methods for vibration - Part 1: Fundamentals (ISO 15242-1:2015, IDT) ISO 21250-2 Rolling bearings - Noise test of rolling bearing greases - Part 2: Test and evaluation method BQ+ Note: GB/T 43617.2-2024, Rolling bearings - Noise testing of rolling bearing greases - Part 2: Test and evaluation method BQ+ (ISO 21250-2:2020, IDT) ISO 21250-3 Rolling bearings - Noise test of rolling bearing greases - Part 3: Test and evaluation method MQ ISO 21250-4 Rolling bearings - Noise test of rolling bearing greases - Part 4: Test and evaluation method NQ 3 Terms and definitions For the purposes of this document, the terms and definitions given in ISO 5593, ISO 15242-1 and the following apply. ISO and IEC maintain terminological databases for use in standardization at the following addresses: ——ISO Online browsing platform: available at https://www.iso.org/obp ——IEC Electropedia: available at http://www.electropedia.org/ 3.1 noise vibration that is a random mechanical energy process of spectral density varying continuously with frequency and perceived as acoustic actions that are neither acoustic shocks nor a series of harmonic tones nor complex tones and which are substantially uniform over time Note: Noise can be represented mathematically, that is as Fourier integral which can be expressed as the sum of a series of plain vibrations. Its distinguishing characteristic, as opposed to other acoustic actions with discrete frequencies, is a spectrum with irregular amplitudes of each frequency. 3.2 start-up noise vSUN noise (3.1) at the start of the bearing testing 3.3 noise level vNL noise (3.1) of the bearing calculated as the average value or rms of measuring points Note: The number of measuring points and measuring time depend on the test method. 3.4 noise peak vNP peak value of the bearing noise (3.1) 3.5 peak count number of peak signals exceeding a defined threshold level 3.6 calibrator measurement standard that provides a sinusoidal vibration speed at certain frequencies and defined amplitudes 3.7 grease damping GD attenuating effect of the lubricant, which is related to the vibration excitation of the bearing 4 Symbols, abbreviated terms and subscripts The symbols and abbreviated terms contained in Table 1 and the subscripts contained in Table 2 apply to the noise testing of greases according to test methods BQ+, MQ and NQ. Table 1 - Symbols and abbreviated terms Symbol Unit Description BQ+a - Method BQ+ according to ISO 21250-2 GD - Grease damping Ha - High band, H-band (1800 Hz to 10000 Hz) ia - Consecutive number La,b - Low band, L-band (50 Hz to 300 Hz) Ma - Medium band, M-band (300 Hz to 1800 Hz) MQa - Method MQ according to ISO 21250-3 M&Ha - Medium band and high band, M&H band (300 Hz to 10000 Hz) n - Number of noise counts NQa - Method NQ according to ISO 21250-4 v µm∙s−1 Vibration velocity ¯(v_i ) µm∙s−1 Vibration velocity, twice smoothed to the counting point i a Can be used as subscript, too, where necessary. b The L-band is used in noise and vibration analysis in the ISO 15242 series. However, this document does not consider this frequency range for grease noise testing and its analysis. Table 2 - Subscripts Subscript-symbol Description greasea Greased bearing NLb Noise level, average value (of vibration velocity) normal Acceptable level of normal noise, greased bearing NPb Noise peak pk Peak value ref Reference, ungreased bearing rms Root mean square value of sinusoidal signal which has the same amplitude with actual peak value range of raceway noise 0-32 Starting interval 0 s to 32 s 32-64 Operating interval 32 s to 64 s SUNb Start-up noise of the greased bearing a This subscript usually is not written (default). b In the MQ method, noise values with this subscript can be expressed in µm∙s-1 or in % based on the reference value of 16,9 µm∙s−1. 5 Basics In the case of grease lubrication, many factors can affect the degree of cleanliness during operation. For the initial lubrication and relubrication, clean grease is always required. Also, in applications where the fatigue life is not an issue (e.g. at very low load), the use of clean greases can be extremely important, for example, as a contribution to a low bearing noise, which is required for applications such as electric motors, fans, etc. The purpose of assessing grease noise is the determination of the grease noise quality or identifying low-noise (quieter) greases. It can contribute to the development and improvement of low noise grease as well as support. The comparison of damping properties of different lubricants shall be made on one bearing type and size, and the bearing shall be mounted in the same way. If all these provisions are followed, the selection of the lubricant with optimum damping characteristics can be performed successfully. It has been found that many factors within the lubricant contribute to the attenuation. For greases, the main parameters are the viscosity, the type of base oil and additive types used. An improvement of damping characteristics can be observed when increasing the base oil viscosity. In addition, the thickener type and its micro-structure, as well as additives, can cause irregular damping properties. Note 1: When abrasive or hard particles (impurities) are over-rolled, raceways (tracks) are damaged. It can result in indentations and increase the stress level (see also ISO 15243). Thus, the fatigue process is accelerated, leading to surface distress including asperity related micro-cracks and micro-spalls where material is released. This in turn leads to noise increase and finally bearing fatigue and bearing failure. In ISO 281, the existence of contamination is described by the factor e c and incorporated in the life modification factor αISO. Note 2: Currently, no sufficient evidence about noise testing of used greases is existing. Therefore, this document is primarily intended for testing of unused greases. 6 Grease noise evaluation method 6.1 General and overview The evaluation method of the grease noise is as follows: ——rotate the deep groove ball bearing in which testing grease is enclosed, and ——analyse the vibration frequencies of the bearing. The analysis method of grease noise varies with each method. Table 3 gives an overview of the features of the methods. Table 3 - Features of each measuring method Feature Method BQ+ MQ NQ Transducer moving coil type Rotational frequency (spindle speed) in min−1 1800a Frequency domain in Hz 300 to 1800 (M-band) 1800 to 10000 (H-band) 300 to 1800 (M-band) 1800 to 10000 (H-band) 300 to 10000 (M&H-band) Filter 1b 800 to 10 000 Hz - - Filter 2b 25 to 400 Hz - - Measuring duration in s 3,2 0 to 32/32 to 64 3/10/30/120 Criterion for classification of grease noise peak level (and “damping factor”) worse value of “standard deviation of peak level” and/or “grease damping factor” peak count a Inner ring rotation, outer ring stationary. b Envelope for peak value.