GB/T 2686-1981 Sliding bearings Powder metallurgy cylindrical bearings with ribs Types, dimensions and tolerances GB/T2686-1981 standard download decompression password: www.bzxz.net
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National Standard of the People's Republic of China Sliding Bearings Types, Dimensions and Tolerances of Powder Metallurgy Simple Bearings with Flanges GB2686-81 This standard applies to powder metallurgy simple bearings with flanges with an inner diameter of 1 to 60 mm for general use in various machinery (hereinafter referred to as bearings). 1 The bearing type is specified in the following figure. The chamfer is allowed to be manufactured according to (a) or (b) in the figure, and the root of the flange is allowed to be manufactured according to (c), (d) or (e) in the figure. 10 Grade Awww.bzxz.net , the outer diameter chamfer is allowed to be 30° (c) as required Note, the bearing material brand marking is in accordance with GB2688--81 "Technical Conditions for Sliding Bearings and Powder Metallurgy Bearings". Issued by the State Administration of Standardization The First Machinery Industry Ministry of the People's Republic of China Implemented on January 1, 1982 Beijing Powder Metallurgy Research Institute. Shanghai Textile Bearing Factory No. 1 GB 2686-81 Marking Example 7-grade bearings with an inner diameter of 20mm, an outer diameter of 26mm, a rib diameter of 32mm, and a length of 25mm are marked: Bearing 20 G7 × 26 × 25 GB2686--81 Inner diameter dimension accuracy 2 The inner diameter, outer diameter, rib outer diameter and thickness, chamfer and other dimensions of the bearing shall be as specified in Table 1, and the length dimension shall be as specified in Table 2. mm GB 2686-81 018882808 55585050 GB2686—81 3 The dimension tolerance of bearings shall be in accordance with GB1800—79 "Tolerances and Fits"; the shape and position tolerances shall be in accordance with GB11821184—80 "Shape and Position Tolerances". Bearings are divided into three types according to the inner diameter dimension tolerance: grade 1, grade 8 and grade 9. The dimension tolerances of inner diameter, outer diameter, length, outer diameter of flange, flange thickness, coaxiality of outer diameter to inner diameter and circular runout tolerance of inner end face of flange to inner diameter shall be in accordance with Table 3. Table 3 Bearing grade ●Grading by flange diameter size. . ·Grading by outer diameter size. ··When the outer diameter size D24mm, s9 is used. Outer diameter of flange Thickness of flange Outer diameter to inner Inner end face of flange to Diameter coaxiality Inner diameter runout 4According to the characteristics of powder metallurgy process, the surface finish of the inner diameter of the bearing should be equivalent to √7, the surface finish of the outer diameter should be equivalent to 6, and the remaining parts should be equivalent to √4~V3 Note: Since the bearing is a porous structure, the surface finish cannot be tested according to the method of GB1031-68 "Surface Finish". The test method can be agreed upon by both parties or determined by the sealed sample method. Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.