Detail of GB/T 307.3-2017

Introduction of GB/T 307.3-2017

Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative. GB/T 307 consists of the following four parts under the general title Rolling bearings: ——GB/T 307.1-2005 Rolling bearings - Radial bearings - Tolerances; ——GB/T 307.2-2005 Rolling bearings－Measuring and gauging principles and methods; ——GB/T 307.3-2017 Rolling bearings - General technical regulations; ——GB/T 307.4-2012 Rolling bearings - Tolerances - Part 4: tolerances for thrust bearings. This is Part 3 of GB/T 307. This part is developed in accordance with the rules given in GB/T 1.1-2009. This part replaces GB/T 307.3-2005 Rolling bearings - General technical regulations; the following main technical changes are made with respect to GB/T 307.3-2005 (the previous edition): ——level, No. and name of some normative references are modified (see clause 2, clause 2 of 2005 edition); ——surface roughness values of the nominal diameter 80~500mm level are subdivided and some of them are modified (see Table 1, Table 1 of 2005 edition); ——internal clearances of four-point-contact ball bearings and double-row and four-row tapered roller bearings, and their measurement methods are added (see 5.6 and 5.16.3); ——requirements for the seal performance, cleanliness and appearance quality are added (see 5.11~5.13); ——calculation method for rated thermal speed of bearing is added (see 5.15.3); ——measurement method for surface roughness of bearing is added (see 5.16.4); ——detection methods for cleanliness and appearance quality of bearing as well as test and assessment of bearing life are added (5.16.8~5.16.10); ——requirements for rolling element (ceramic ball and tapered roller), cage, seal ring and dust cover are added (see 6.1~6.3); ——requirements for locknut and locking device are added (see 7.3); ——classification and reason analysis of failure mode are added (see 8.3). This part was proposed by China Machinery Industry Federation. This part is under the jurisdiction of the National Technical Committee on Rolling Bearing of Standardization Administration of China (SAT/TC 98). The previous editions of standards replaced by this part are as follows: ——GB 307-1964 (partial) and GB 307-1977 (partial); ——GB/T 307.3-1984, GB/T 307.3-1996 and GB/T 307.3-2005. Rolling Bearings - General Technical Regulations 1 Scope This part of GB/T 307 specifies the general technical regulations for rolling bearings. This part is applicable to the rolling bearings for general purpose. Supplementary specification may be prepared separately for the bearings for special purpose. 2 Normative references The following referenced documents are indispensable for the application 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. GB/T 271 Rolling bearings - Classification GB/T 272 Rolling bearings - Identification code GB/T 273.1 Rolling bearings - Boundary dimensions general plan - Part 1: tapered roller bearings GB/T 273.2 Rolling bearings - Thrust bearings - Boundary dimensions, general plan GB/T 273.3 Rolling bearings - Boundary dimensions, general plan - Part 3: radial bearings GB/T 274 Rolling bearings - Chamfer dimension - Maximum values GB/T 275 Rolling Bearings - Fits GB/T 305 Rolling bearings - Snap ring groove and snap ring on outer ring - Dimensions and tolerances GB/T 307.1 Rolling bearings - Radial bearings - Tolerances GB/T 307.2 Rolling bearings－Measuring and gauging principles and methods GB/T 307.4 Rolling bearings - Tolerances - Part 4: tolerances for thrust bearings GB/T 308.1 Rolling bearings - Balls - Part 1: steel balls GB/T 308.2 Rolling bearings - Balls - Part 2: ceramic balls GB/T 309 Rolling bearings - Needle rollers GB/T 4604.1 Rolling bearings - Internal clearance - Part 1: radial internal clearance for radial bearings GB/T 4604.2 Rolling bearings - Internal clearance - Part 2: axial internal clearance for four-point-contact ball bearings GB/T 4661 Rolling bearings - Cylindrical rollers GB/T 4662 Rolling bearings - Static load ratings GB/T 5868 Rolling bearings - Mounting dimensions GB/T 6391 Rolling bearings - Dynamic load ratings and rating life GB/T 6930 Rolling bearings - Vocabulary GB/T 7811 Rolling bearings - Symbols for physical quantities GB/T 7813 Rolling bearings - Split type plummer block housings - Boundary dimensions GB/T 8597 Rolling bearings - Rust proof packaging GB/T 9160.1 Rolling bearings - Accessories - Part 1: adapter sleeve assemblies and withdrawal sleeves GB/T 9160.2 Rolling bearings - Accessories - Part 2: locknuts and locking devices GB/T 18254 High-carbon chromium bearing steel GB/T 24605 Rolling bearings - Marking for products GB/T 24607 Rolling bearings - Test and assessment for life and reliability GB/T 24608 Inspection rules for rolling bearings and commercial parts GB/T 24609 Rolling bearings - Thermal speed rating - Calculation and coefficients GB/T 24610.2 Rolling bearings - Measuring methods for vibration - Part 2: radial ball bearings with cylindrical bore and outside surface GB/T 24610.3 Rolling bearings - Measuring methods for vibration - Part 3: radial spherical and tapered roller bearings with cylindrical bore and outside surface GB/T 24610.4 Rolling bearings - Measuring methods for vibration - Part 4: radial cylindrical roller bearings with cylindrical bore and outside surface GB/T 24611 Rolling bearings - Damage and failures - Terms, characteristics and causes GB/T 25767 Rolling bearings - Tapered rollers GB/T 25769 Rolling bearings - Measuring methods for radial internal clearance GB/T 28268 Rolling bearings - Specifications of pressed cages GB/T 32323 Rolling bearings - Measuring methods for axial internal clearance of four-point-contact ball bearings GB/T 32325 Rolling bearings - Specifications for vibration (velocity) of deep groove ball bearings GB/T 32333 Rolling bearings - Measuring methods and specifications for vibration(acceleration) JB/T 1255 Specification for heat-treatment of rolling bearing parts made from high carbon chromium steel JB/T 6639 Rolling bearings - Skeleton rubber seal - Specifications JB/T 6641 Rolling bearings - Residual magnetism and its assessment method JB/T 7048 Rolling bearings - Engineering plastic cages - Specifications JB/T 7050 Rolling bearings - Assessment methods for cleanliness JB/T 7051 Rolling Bearing Parts - Methods for the Measurement and Assessment of Surface Roughness JB/T 7752 Rolling Bearings - Sealed deep groove ball bearings - Specifications JB/T 8236 Rolling bearings - Internal clearances and adjusting methods for double-row and four-row tapered roller bearings JB/T 8874 Rolling bearings - Split type plummer block housings - Specifications JB/T 8922 Rolling bearings - Specifications for vibration (velocity) of cylindrical roller bearings JB/T 10236 Rolling bearings - Specifications of vibration (velocity) for tapered roller bearings JB/T 10237 Rolling bearings - Specifications of vibration (acceleration) for tapered roller bearings JB/T 10239 Rolling bearings - Curled shields for deep groove ball bearings - Specifications JB/T 11841 Rolling bearing parts - Metal solid cages - Specifications 3 Terms and definitions For the purpose of this document, the terms and definitions given in GB/T 6930 apply. 4 Symbols For the purposes of this document, the symbols given in GB/T 7811 apply. 5 Bearing 5.1 Classification The bearing classification shall meet the requirements of GB/T 271. 5.2 Identification code The identification code of bearing shall meet the requirements of GB/T 272. 5.3 Boundary dimension The boundary dimensions of bearing shall meet the requirements of GB/T 273.1, GB/T 273.2 and GB/T 273.3. 5.4 Tolerance grade and tolerance Bearing is graded according to dimensional tolerance and rotating accuracy. The tolerance grade is from low to high, and the tolerance values shall meet the requirements of GB/T 307.1 and GB/T 307.4. Radial bearings (except for tapered roller bearings) are classified into ordinary grade, Grades 6, 5, 4 and 2. Tapered roller bearings are classified into ordinary grade, Grades 6X, 5, 4 and 2. Thrust bearings are classified into ordinary grade, Grades 6, 5 and 4. 5.5 Maximum chamfer dimension The maximum chamfer dimension of bearing shall meet the requirements of GB/T 274. 5.6 Internal clearance The radial internal clearance for radial bearing shall meet the requirements of GB/T 4604.1. The axial internal clearance for four-point contact ball bearing shall meet the requirements of GB/T 4604.2. The internal clearance for double-row and four-row tapered roller bearings shall meet the requirements of JB/T 8236. 5.7 Surface roughness The roughness for mating surface and end surface of bearing shall meet the requirements of Table 1. Table 1 Roughness for Mating Surface and End Surface of Bearing Surface name Tolerance grade of bearing Nominal diameter of bearing a/mm > 30 80 200 500 1 600 ≤30 80 200 500 1 600 2 500 Ra max/μm Inner bore surface of inner race Ordinary grade 0.8 0.8 0.8 1 1.25 1.6 6X(6) 0.63 0.63 0.8 1 1.25 - 5 0.5 0.5 0.63 0.8 1 - 4 0.25 0.25 0.4 0.5 - - 2 0.16 0.2 0.32 0.4 - - Outer cylindrical surface of outer race Ordinary grade 0.63 0.63 0.63 0.8 1 1.25 6X(6) 0.32 0.32 0.5 0.63 1 - 5 0.32 0.32 0.5 0.63 0.8 - 4 0.25 0.25 0.4 0.5 - - 2 0.16 0.2 0.32 0.4 - - End surface of race Ordinary grade 0.8 0.8 0.8 1 1.25 1.6 6X(6) 0.63 0.63 0.8 1 1 - 5 0.5 0.5 0.63 0.8 0.8 - 4 0.4 0.4 0.5 0.63 - - 2 0.32 0.32 0.4 0.4 - - a Look up the table for the inner bore surface of inner race and its end surface as per the diameter of inner bore, and the outer cylindrical surface of outer race and its end surface as per the outer diameter. Look up the table for the one-direction thrust bearing washer and its end surface as per the diameter of inner bore of bearing race, and the two-direction thrust bearing washer (including central washer) and its end surface as per the diameter of inner bore with round and integrated housing washer. 5.8 Materials and heat treatment for bearing ring and rolling element High-carbon chromium bearing steel meeting the requirements of GB/T 18254 is generally adopted for bearing race and rolling element, and the heat treatment quality shall meet those specified in JB/T 1255; other material meeting performance requirements may also be adopted, and the heat treatment quality shall meet those specified in relevant standards. 5.9 Residual magnetism limit Residual magnetism limit of bearing shall meet the requirements of JB/T 6641. 5.10 Vibration limit The vibration limit of bearing shall meet the requirements of GB/T 32325, GB/T 32333, JB/T 8922, JB/T 10236 and JB/T 10237 respectively. 5.11 Sealing performance Sealed bearing shall be provided with good sealing performance, and the specification for sealed deep groove ball bearing shall meet the requirements of JB/T 7752. 5.12 Cleanliness Cleanliness of bearing shall meet the requirements of JB/T 7050. 5.13 Appearance quality Bearings shall be free of surface defects such as cracks, rust and obvious bumps that affect installation or usability.

Contents of GB/T 307.3-2017

Foreword i 1 Scope 2 Normative references 3 Terms and definitions 4 Symbols 5 Bearing 6 Parts for bearing 7 Accessories for bearing 8 Bearing application