1、BRITISH STANDARD CONFIRMED MAY 1991 BS 2062-1: 1959 Incorporating Amendment No. 1 Specification for Gear hobs Part 1: Hobs for general purposes 1 d.p. to 20 d.p. inclusiveBS2062-1:1959 This British Standard, having been approved by the MechanicalEngineering IndustryStandards Committee and endorsed b
2、y the Chairman ofthe Engineering Divisional Council, was published under theauthority of the General Council on 18December 1959 BSI 05-2000 First published December 1953 First revision December 1959 The following BSI references relate to the work on this standard: Committee reference MEE/127 Draft f
3、or comment CZ(MEE)4229 ISBN 0 580 35518 7 Co-operating organizations The Mechanical Engineering Industry Standards Committee, under whose supervision this British Standard was prepared, consists of representatives from the following Government departments and scientific and industrial organizations:
4、 Admiralty* Institute of Marine Engineers Air Ministry Institute of Petroleum Associated Offices Technical Committee Institution of Civil Engineers Association of Consulting Engineers (Incorporated) Institution of Gas Engineers British Chemical Plant Manufacturers Association Institution of Heating
5、and Ventilating British Compressed Air Society Engineers British Electrical and Allied Manufacturers Institution of Mechanical Engineers Association* Institution of Mechanical Engineers British Engineers Association (Automobile Division) British Gear Manufacturers Association* Institution of Product
6、ion Engineers* British Internal Combustion Engine Locomotive and Allied Manufacturers Manufacturers Association Association of Great Britain British Iron and Steel Federation Machine Tool Trades Association* British Railways, The British Transport Ministry of Aviation* Commission Ministry of Labour
7、and National Service Crown Agents for Oversea Governments and Ministry of Power Administrations Ministry of Transport D.S.I.R.National Engineering Laboratory* Ministry of Works Electricity Council, The Generating Boards and National Coal Board the Area Boards for England and Wales National Physical
8、Laboratory (D.S.I.R.) Engineering Equipment Users Association Radio Industry Council Gas Council War Office High Commission of India The Government departments and scientific and industrial organizations marked with an asterisk in the above list, together with the following, were directly represente
9、d on the Committee entrusted with the preparation of this standard: Board of Trade Parsons and Marine Engineering Turbine Milling Cutter and Reamer Association Research Association North East Coast Institution of Engineers and Society of Motor Manufacturers and Traders Shipbuilders Manufacturers of
10、gear hobs Amendments issued since publication Amd. No. Date Comments 4015 December 1960 Indicated by a sideline in the marginBS2062-1:1959 BSI 05-2000 i Contents Page Co-operating organizations Inside front cover Foreword ii 1 Scope 1 2 Terms and notation 1 3 Tooth form 2 4 Dimensions 2 5 Bore 3 6 H
11、ubs 3 7 Gashes 3 8 Keys and keyways 4 9 Permissible errors 6 10 Marking 8 11 Recommended ordering instructions 8 Appendix A 9 Appendix B Hobs with taper bores 9 Appendix C Marking of hobs 10 Appendix D Ordering instructions 10 Appendix E Equivalent pitches 11 Appendix F 12 Appendix G Approximate met
12、ric equivalents 13 Figure 1 General hob terms 1 Figure 2 B.S. basic rack tooth profile (in terms of unit normal diametral pitch) 3 Figure 3 Tooth gashes 4 Table 1 Dimensions of gear hobs for general purposes 2 Table 2 Limiting dimensions for keyways 5 Table 3 Limiting dimensions for keys 5 Table 4 P
13、ermissible errors Grades AA, A, B and D hobs 6 Table 5 Recommended limiting dimensions for parallel arbor diameters 9 Table 6 Recommended dimensions for taper arbors 9 Table 7 Recommended relationship between taper arbors and hob diameters 10BS2062-1:1959 ii BSI 05-2000 Foreword This standard makes
14、reference to the following British Standards: BS 350, Conversion factors and tables. BS 436, Machine cut gears. A.Helical and straight spur. BS 2519, Glossary of terms and notation for toothed gearing. BS 2062, Gear hobs Part2: Hobs for turbine gears: Grade AA: Accuracy. This revision of the1953edit
15、ion has been carried out under the authority of the Mechanical Engineering Industry Standards Committee in response to various requests. In drafting this revision the Committee has taken account of the work of the International Standards Organization and of current American specifications. This spec
16、ification now covers the range1to20d.p. inclusive only and the tooth form and pitches given are in agreement with ISO Recommendations Nos.R53andR54and BS436:1940, Figure5. 1)A new specification for pitches finer than20d.p. will be drafted in due course. The need for a hob for general purposes of gre
17、ater accuracy than formerly has been met by including a Grade AA hob in Part1. At the same time the opportunity has been taken to illustrate the elements to which each type of permissible error refers, indicating a typical method of test similar to other recent British Standards for gear cutting too
18、ls. Details of the marking recommended for hobs, and the information to be given when ordering, are given in Appendix C and Appendix D respectively. The revision of Part2 1)of the1953edition will be published at a later date and the Committee considers that the publication of the revision of Part1sh
19、ould not be delayed until Part2is completed. A table of approximate equivalents is given in Appendix G. More precise conversions should be based on the tables given in BS 350,“Conversion factors and tables”. A British Standard does not purport to include all the necessary provisions of a contract. U
20、sers of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages1to 14, an inside back cover and
21、a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. 1) ISO RecommendationR53, “Basic rack of cylindrical gears for general engineering”. ISO Recommendation R 54, “Modules
22、and diametral pitches of cylindrical gears for general engineering”. BS 436, “Machine cut gears. A. Helical and straight spur”. BS 2062, “Gear hobs”. Part2. Hobs for turbine gears: Grade AA: Accuracy.BS2062-1:1959 BSI 05-2000 1 1 Scope Part 1 of this British Standard applies to non-topping single-st
23、art right-hand and left-hand finishing hobs for helical and straight spur gears for general purposes. It covers the following grades of accuracy: Grade C (which is given in American and other specifications) is not included. Unless otherwise specified by the purchaser, the hobs supplied in accordanc
24、e with this BritishStandard will be right-hand. 2 Terms and notation The general terms used, common to gears and hobs, are taken from BS2519, “Glossary of terms and notation for gearing”. Grade AA Grade A Ground profile hobs. Grade B Grade D: Unground profile hobs. Figure 1a Figure 1b Figure 1c Figu
25、re 1 General hob terms BS2062-1:1959 2 BSI 05-2000 Table 1 Dimensions of gear hobs for general purposes (See Figure 1) 3 Tooth form The hob tooth shall be such that it will generate gears corresponding to the basic rack tooth profile 2)shown in Figure 2, having profile modification within the range
26、stated. 4 Dimensions The dimensions of the hobs shall be in accordance with Table 1, subject to the provisions of Clauses5 to9 inclusive. Equivalent pitches are set out in Appendix E and the preferred pitches are printed in bold type. Normal diametral pitch Overall Length of recess (approximate) Bor
27、e diameter Hub Outside diameter Length Diameter (approximate) Length (approximate) in. in. in. in. in. in. 1 1 1 / 4 1 1 / 2 1 3 / 4 2 10 3 / 4 8 3 / 4 8 7 1 / 4 6 15 12 10 9 8 5 4 3 1 / 2 3 2 3 / 4 2 1 / 2 2 2 2 1 1 / 2 4 1 / 2 3 3 / 4 3 3 / 4 3 1 / 2 2 1 / 2 3 / 8 3 / 8 5 / 16 5 / 16 5 / 16 2 1 /
28、4 2 1 / 2 2 3 / 4 3 3 1 / 2 5 3 / 4 5 1 / 2 5 1 / 4 4 1 / 2 4 1 / 4 8 7 6 5 4 3 / 4 2 3 / 4 2 1 / 4 2 1 3 / 4 1 5 / 8 1 1 / 2 1 1 / 2 1 1 / 2 1 1 / 4 1 1 / 4 2 1 / 2 2 1 / 2 2 1 / 2 2 1 / 4 2 1 / 4 1 / 4 1 / 4 1 / 4 1 / 8 1 / 8 4 4 1 / 2 5 5 1 / 2 6 4 3 3 / 4 3 1 / 2 3 1 / 2 3 1 / 2 4 3 3 / 4 3 1 /
29、2 3 1 / 2 3 1 / 2 1 3 / 8 1 1 / 4 1 1 / 4 1 1 / 4 1 1 / 4 1 1 / 4 1 1 / 4 1 1 / 4 1 1 / 4 1 1 / 4 2 1 / 8 2 1 / 16 2 1 / 16 2 1 / 16 2 1 / 8 1 / 8 1 / 8 1 / 8 1 / 8 7 8 9 10 12 3 1 / 4 3 3 3 2 3 / 4 3 1 / 4 3 3 3 2 3 / 4 1 1 / 8 1 1 1 1 1 1 / 4 1 1 / 4 1 1 / 4 1 1 / 4 1 1 / 4 2 1 15 / 16 1 15 / 16 1
30、 15 / 16 1 7 / 8 1 / 8 1 / 8 1 / 8 1 / 8 1 / 8 14 16 18 20 12 2 1 / 2 2 1 / 2 2 1 / 2 2 1 / 2 2 2 1 / 2 2 1 / 2 2 1 / 2 2 1 / 2 2 7 / 8 7 / 8 7 / 8 7 / 8 3 / 4 1 1 / 4 1 1 / 4 1 1 / 4 1 1 / 4 3 / 4 1 7 / 8 1 7 / 8 1 7 / 8 1 7 / 8 1 3 / 16 1 / 8 1 / 8 1 / 8 1 / 8 1 / 8 14 16 18 20 1 7 / 8 1 7 / 8 1 7
31、 / 8 1 7 / 8 1 7 / 8 1 7 / 8 1 7 / 8 1 7 / 8 5 / 8 5 / 8 5 / 8 5 / 8 3 / 4 3 / 4 3 / 4 3 / 4 1 3 / 16 1 3 / 16 1 3 / 16 1 1 / 4 1 / 8 1 / 8 1 / 8 1 / 8 NOTE 1Although dimensions are given for the hub diameter this feature should be as large as possible, and this also applies to adjacent spacing coll
32、ars. NOTE 2The hub periphery is the reference datum surface. NOTE 3Preferred pitches are shown in bold type. 2) See BS436, Figure 5.BS2062-1:1959 BSI 05-2000 3 5 Bore a) The standard form of bore shall be parallel 3)with longitudinal keyways in accordance with Clause8 below. A chamfer shall be provi
33、ded at the outer ends of the bore, the dimensions being as set out below: If preferred, an equivalent radius may be substituted for a chamfer. Standard bores shall be finished straight and parallel, within the tolerances given inTable 4, for75percent of each bearing length for GradesAA, A and B hobs
34、 and50percent for GradeD hobs. Recommendations for arbor dimensions and tolerances for standard bores 3)are given in Appendix A, Table 5. 6 Hubs Hubs may be cylindrical or conical. 7 Gashes All hobs shall preferably be gashed so that the cutting faces are substantially normal to the tooth helix, wit
35、h a recommended lead of180in. Axial gashing is permitted up to 4 tooth lead angle on Grade A, B and D hobs and up to 2 tooth lead angle on Grade AA hobs. Figure 2 B.S. basic rack tooth profile (in terms of unit normal diametral pitch) 3) Note that, if a taper bore is required, it is recommended that
36、 the arbor should comply with the provisions of Appendix B, Table 6. It should also be noted that the hob overall dimensions given in Table 1 do not apply and the recommended relationship between taper arbors and hob diameter is set out in Appendix B, Table 7. Diameter of bore Chamfer (see Figure 1b
37、) in. in. 3 / 4 Over 3 / 4 Not less than 1 / 32 Not less than 1 / 16BS2062-1:1959 4 BSI 05-2000 8 Keys and keyways Key and keyway dimensions shall be in accordance with Table 2 and Table 3. The error of radial and axial alignment of the keyway shall be such that interference does not occur between t
38、he key and keyway at any point throughout the hob length when the keyway is within the limits of width at all points. Figure 3 Tooth gashesBS2062-1:1959 BSI 05-2000 5 Table 2 Limiting dimensions for keyways Table 3 Limiting dimensions for keys Nominal diameter A Limiting dimensions Corner radius R W
39、idth of keyway B Diameter of bore plus depth of keyway C min. max. min. max. in. in. in. in. in. in. 3 / 4 1 1 / 4 0.127 0.314 0.132 0.319 0.822 1.385 0.837 1.400 1 / 32 1 / 16 1 1 / 2 2 2 1 / 2 0.377 0.502 0.627 0.382 0.507 0.632 1.666 2.198 2.733 1.681 2.213 2.748 1 / 16 1 / 16 1 / 16 Nominal diam
40、eter of arbor A Nominal size of key Limiting dimensions Depth of key D Corner radius of key R Width of key B Diameter of arbor plus height of key C min. max. min. max. in. in. in. in. in. in. in. in. 3 / 4 1 1 / 4 1 / 8 5 / 16 0.120 0.307 0.125 0.312 0.807 1.370 0.812 1.375 0.125 0.312 1 / 32 1 / 16
41、 1 1 / 2 2 2 1 / 2 3 / 8 1 / 2 5 / 8 0.370 0.495 0.620 0.375 0.500 0.625 1.651 2.183 2.713 1.656 2.188 2.718 0.375 0.500 0.625 1 / 18 1 / 16 1 / 16BS2062-1:1959 6 BSI 05-2000 9 Permissible errors The errors appropriate to each grade of hob shall not exceed those given in Table 4. Table 4 Permissible
42、 errors Grades AA, A, B and D hobs (Expressedinten-thousandthsofaninch) Element No. Illustration Test Grade Preferred diametral pitch (seeNote2for non-preferred) 1, 1 1 / 4 , 1 1 / 2 2 and 2 1 / 2 3 4 5 6, 7, 8 10 and 12 16 20 Hub reference 1 Axial run-out AA 3 2 2 2 2 2 2 2 A 8 5 2 2 2 2 2 2 2 Datu
43、m surfaces B 10 8 4 4 3 3 2 2 2 D 10 8 5 5 4 4 3 3 3 2 Radial run-out AA 4 3 3 3 3 2 2 2 A 10 5 4 3 3 3 2 2 2 B 12 8 6 5 4 4 3 2 2 D 15 10 8 8 6 6 5 5 5 Outside diameter 3 Radial run-out AA 15 10 10 10 10 10 5 5 A 30 20 15 15 10 10 10 10 10 B 40 30 25 20 15 15 15 10 10 D 60 55 50 45 35 35 30 25 25 T
44、ooth lead variation 4 Variation along tooth helix from tooth to tooth AA 3 2 2 2 2 1.5 1.5 1.5 A 7 5 4 3 2 2 2 2 2 B 10 8 6 4 3 3 3 3 3 D 25 20 16 14 12 10 10 8 8 5 (see also Appendix F) Variation along tooth helix in one convolution (cyclic pitch error) AA 6 3.5 3.5 3 3 3 2 2 A 25 18 10 8 6 5 5 4 4
45、 B 35 25 17 11 9 7 7 6 6 D 60 50 40 30 25 20 20 18 18 6 Variation along tooth helix in any three consecutive convolutions (cumulative pitch error) AA 12 6 5 4 4 3 3 3 A 38 26 15 12 9 8 8 7 7 B 53 38 22 16 12 11 10 9 9 D 120 100 80 60 50 40 35 25 25 Tooth 7 Thickness (minusonly) AA 15 10 10 10 10 5 5
46、 5 A 30 20 15 15 10 10 10 10 10 B 30 20 15 15 10 10 10 10 10 D 40 35 30 25 20 20 20 20 20 8 Permissible error over the straight flank from the design form AA 4 3 2 2 2 1.5 1.5 1 A 10 5 3 3 2 2 2 2 2 B 16 8 5 5 4 3 3 3 3 D 80 55 30 18 12 8 8 6 6BS2062-1:1959 BSI 05-2000 7 Table 4 Permissible errors G
47、rades AA, A, B and D hobs (Expressedinten-thousandthsofaninch) Element No. Illustration Test Grade Preferred diametral pitch (seeNote2for non-preferred) 1, 1 1 / 4 , 1 1 / 2 2 and 2 1 / 2 3 4 5 6, 7, 8 10 and 12 16 20 Tooth (continued) 9 Start of profile modification (plus or minus) AA 140 120 100 8
48、0 60 40 30 20 A 200 180 160 140 120 100 80 60 40 B 220 200 180 160 140 120 100 80 50 D 260 240 220 200 180 160 140 120 120 10 Symmetry of start of profile modification AA 80 80 60 50 40 30 15 15 A 150 130 120 100 90 80 60 50 35 B 180 150 130 120 100 90 80 70 45 D 200 180 160 140 120 110 100 90 90 Cu
49、tting faces of gashes 11 Adjacent spacing error AA 20 10 10 10 10 10 10 10 A 40 30 25 20 15 10 10 10 10 B 50 45 40 30 20 15 15 10 10 D 60 60 50 50 30 25 25 20 20 12 Cumulative spacing error AA 40 30 30 30 30 20 20 15 A 80 60 50 40 30 30 30 25 25 B 100 90 80 60 50 50 50 40 35 D 120 120 100 100 80 80 70 60 60 13 Radial alignment of gash over cutting depth AA 10 10 6 6 5 5 5 5 A 30 15 10 8 6 5 5 5 5 B 50 25 15 10 8 7 7 5 5 D 100 75 50 40 30 20 20 15 15 14 Departure (plus or minus) from
