1、Plain bearings Part 4: Artificial carbon bushes ICs 21.1 00.10 Descriptors: Plain bearings, bushes, artificial carbon. Gleitlager - Teil 4: Buchsen aus Kunstkohle DIN 1850-4 Supersedes August 1970 edition. In keeping with current practice in standards published by the International Organization for
2、Standardization (ISO), a comma has been used throughout as the decimal marker. Foreword This standard has been prepared by the Normenausschu Gleitlager (Plain Bearings Standards Committee). Amendments In comparison with the August 1970 edition, the standard has been editorially revised and its conte
3、nt brought up to date with the state of the art. Previous editions DIN 146: 1921-01, 1932-08; DIN 147: 1921-01, 1932-08; DIN 16902: 1944-10; DIN 1850: 1957-04; DIN 1850-1 1959-05; DIN 1850-4: 1969-03, 1970-08. Dimensions in mm 1 Scope This standard specifies dimensions, tolerances, materials and the
4、 finish for artificial carbon bushes used as plain bearings, with or without lubrication grooves as specified in IS0 121 28. 2 Normative references This standard incorporates, by dated or undated reference, provisions from other publications. These normative references are cited at the appropriate p
5、laces in the text and the titles of the publications are listed below. For dated references, subsequent amendents to or revisions of any of these publications apply to this standard only when incorporated in it by amendment or revision. For undated references, the latest edition of the publication r
6、eferred to applies. IS0 2768-1 : 1989 General tolerances - Part 1: Tolerances for linear and angular dimensions without individual tolerance indications IS0 12128 : 1995 Plain bearings - Lubrication holes, grooves and pockets - Dimensions, types, desig- nation and their application to bearing bushes
7、 Continued on pages 2 and 3. Translation by DIN-Sprachendienst. In case of doubt, the German-language original should be consulted as the authoritative text. O No part of this translation may be reproduced without the prior permission of Ref. No. DIN 1850-4 : 1998-07 DIN Deutsches lnstitut fr Normun
8、g e. V., Berlin. Beutb Verlag GmbH, D-i0772 Berlin, has the exclusive right of sale for German Standards (DIN-Normen). English price group 05 Sales No. O1 05 01.99 Page 2 DIN 1850-4 : 1998-07 48 I 58 I 66 3 Dimensions and designation General tolerances shall be class m tolerances as in IS0 2768-1. S
9、pecifications for the standard tolerance grade (IT) are based on d, or d,. 20 28 40 50 7 0,8 0,8 Type M Cylindrical bearing Type N Flanged bearing Designation of a type M cylindrical bearing (M) with an inside diameter, d, of 18 mm (IS0 tolerance class D8), an outside diameter, d, of 24 mm (IS0 tole
10、rance class z8), and a width, b, of 18 mm, made from artificial carbon: Bearing DIN 1850 - M 18 D8 x 24 z8 x 18 Table 1: Nominal sizes 4 5 6 8 10 I I I I 12 I I 14 15 I I 16 I 55 I 66 I 74 I 25 1 36 I 45 I 56 I 7 I 0,8 I 0,8 I I I 18 I 60 I 75 I 83 I 25 1 36 I 50 I 63 I 7 I 0,8 I 0,8 I I I 20 34 40
11、22 1 I (24) 25 14 20 25 0,4 0,4 14 20 25 - 0,6 0,6 12 16 22 28 6 0,6 0,6 I I I 80110011101 32 I50 I63 I 801 8 11 11 I (27) 28 I I I 90 111011201 36 I56 I70 I90 Il0 11 11 I I I 30 38 I 44 I 12 I 18 I 25 I 32 I 6 I0,6 I0,6 I 95111511251 40 I56 I80 1100) 10 11 11 1 32 I40 I46 I 14 1 18 I 25 I 32 I 6 I0
12、,6 I0,6 1100112011301 40 I63 I80 11001 10 11 11 Sizes in brackets should only be used in exceptional cases. Page 3 DIN I 850-4 1998-07 4 Material Bushes shall be made from artificial carbon. The grade shall either be agreed upon or shall be at the manufac- turers discretion. 5 Finish Unless otherwis
13、e specified, edges shall be chamfered at an angle of about 45“. The surface of bushes shall be precision-finished. NOTE: Since artificial carbon has a porous structure, its surface roughness cannot be exactly defined. 5.1 Assembly at low temperatures The tolerances for the bearings before assembly a
14、t a low temperature shall be F7 for the inside diameter, d, s6 for the outside diameter, d, and H7 for the bearing bore. The insertion pin used for pressing the bush into the housing shall have a hardened shoulder and be produced to tolerance h5. This will result in a tolerance on d, ranging from H7
15、 to H8. When pressing the bush into its housing, attention should be paid to the fact that artificial carbon has a lower thermal expansion than metallic materials. An H7/s6 fit as recommended for steel housings is deemed sufficient for operating temperatures up to 150 OC. This temperature will be lo
16、wer for housings made from materials having a greater coefficient of linear thermal expansion than steel. For housings made from plastics, a tighter interference fit is acceptable because plastics are considerably less prone to abrasive wear than metallic materials. 5.2 Assembly at elevated temperat
17、ures The tolerances for the bearings before assembly at an elevated temperature shall be D8 for the inside diameter, d, x8 to zb8 for the outside diameter, d, and H7 for the bearing bore. Bushes are to be pressed and shrunk into the housing at elevated temperatures. For an H7/z8 interference fit, th
18、e preheat temperature of the bearing housing shall be so chosen as to permit cold bushes to be fitted easily into the housing (for steel, this is a temperature of about 300 to 350 OC). By this method, diameter d, is reduced by about three to six tolerances zones (this reduction will be greater for l
19、arger diameters), since the reduction in diameter will amount to 70 to 100 % of the wall thickness. To ensure that the specified tolerances are complied with after fitting (and hot-shrinking) of the bush, this should be finished to size by reaming. Flanged bushes are less suitable for fitting at ele
20、vated temperatures since, owing to the brittleness of artifical carbon, the flange may break off from the body due to residual stresses. Where fitting of bushes at elevated temperatures is not possible, bushes fitted at a low temperature shall be secured against twisting where elevated operating tem
21、peratures are to be expected. NOTE: Different tolerances and surface finishes may be required for bushes which are to be bonded, since fitting of these bushes need not necessarily be carried out by pressing. Where compliance with tolerances other than those specified here is required, this should be
22、 agreed at the time of ordering. For details, contact the adhesive or bush manufacturer. Other relevant standards DIN 1850-3 Plain bearings - Sintered bushes DIN 1850-5 Plain bearings - Thermoset bushes DIN 1850-6 Plain bearings - Thermoplastic bushes IS0 4379 : 1993 Plain bearings - Copper alloy bushes
