1、AMERICAN NATIONAL STANDARD HOBS ANSI B94.7 - 1980 REVISION OF ANSI B94.7-1966 (R 197211 . - - -. REAFFIRMED 1995 FOR CURRENT COMMITTEE PERSONNEL PLEASE SEE ASME MANUAL AS-1 1 SECRE TARlA T THE AMERICAN SOCIETY OF MECHANICAL ENGINEERS PUBLISHED BY THE AMERICAN SOCIETY OF MECHANICAL ENGINEERS United E
2、ngineering Center 345 East 47th Street New York, N. Y. 1001 7 Date of Issuance: March 15, 1981 No part of this document may be reproduced in any form, in an electronic retrieval system or otherwise, without the prior written permission of the publisher. Copyright 01981 by THE AMERICAN SOCIETY OF MEC
3、HANICAL ENGINEERS All Rights Reserved Printed in USA. FOREWORD In response to requests from both users and producers a project was initiated in December of 1961 to establish standards for gear cutting-tools. Sectional Committee B5 approved this project at their annual meeting in 1961 and created tec
4、hnical committee TC-14 to prepare such standards. In 1962 Sectional Committee B5 was divided and Technical Committees identified with the general area of “Metal Cutting” were transferred to a new Sectional Committee B94. The first meeting of TC-14; reporting to Sectional Committee B94, was held in D
5、ecember 1962. It was at this time decided to divide the general subject into three areas, i.e., Hobs, Gear Shaper Cutters and Shaving Cutters. The initial activity was to prepare a proposal for an American Standard on Hobs, using the industry standards (MCTI) as the basis for consideration. A propos
6、al covering Hobs was submitted to industry in September 1964 for review and comment. All of the resulting responses were considered at a meeting of TC-14 in March 1965 and they then approved a final proposal. The B94 TC-15 Editorial Committee reviewed the proposal and it was submitted on October 27,
7、 1965 to the B94 Sectional Committee for Letter Ballot. Following approval by B94 the proposal was approved by the Sponsor, ASME, and on June 22, 1966 it was approved by the American Standards Association and designated B94.7-1966. The committee was assigned the project of reviewing ASA B94.7-1966 f
8、or reaffirmation or revision. The consensus was to review the existing standard and add additional hob sizes to include the larger size nomi- nal diameter bores based on the requirements of the larger hobbing machines in use today. Multiple-thread involute spline hob sizes and tolerances have also b
9、een added. We have also made a number of editorial changes. The current revision, after approval of the B94 Standards Committee and the Secretariat, was approved by ANSI on October 27, 1980 and designated B94.7-1980. iii AMERICAN NATIONAL STANDARDS COMMITTEE B94 Cutting Tools, Holders, Drivers and B
10、ushings (The following is the roster of the Committee at the time of approval of this Standard) OFFICERS A. R. Neinast, Chairman A. M. Mezey, Vice-chairman R. K. Buckley, Secretary AMERICAN GEAR MANUFACTURERS ASSOCIATION f. M. Dean, Jr., Mechanical Technology, Inc. Latham, New York R. C. Brown, Alte
11、rnate, Manager of Engineering Services, Arlington, Virginia AMERICAN SOCIETY OF MECHANICAL ENGINEERS M. E. Merchant, Jr., Cincinnati Milacron, Inc., Cincinnati, Ohio C. J. Oxford, Jr., National Twist Drill 6 y2 70 % 75 S NORMAL DIAMETRAL PITCH Element RUNOUT* AA- 11 11111 A222222222 22 c443332222 22
12、 2 2 2 2 3 3 3 4 4 B HubFace 22 D554443333 - AA- 11 21111 Hub Diameter A333332222 8554443222 22 - D886665555 22 c554443222 22 AA - - 55555 54 A 15 15 10 10 - 25 25 25 30 35 35 35 45 45 D 10 12 12 12 12 17 17 17 20 25 25 C 7 10 10 10 10 15 15 15 15 20 20 B 7 10 10 10 10 10 10 Outside Diameter LEAD AA
13、- 1.7 1.7 1.7 1.7 1.7 1.7 1.7 - Tooth to Tooth A543222222 8864333333 22 - - 8 10 10 10 10 12 14 16 20 D 43 C1286544444 32 AA- 53 66665 A221310 - 23 25 25 26 27 32 37 50 60 D of Helix 11 11 11 12 12 12 12 15 18 27 40 C 85 8 9 9 10 10 12 14 22 29 B InAny One Turn 64 6 7 7 7 7 8 TOOTH AA- 1.7 1.7 A2222
14、22 Pressure 3 3 3 3 3 4 C Angle2 3 3 3 3 3 4 B Dl2 8 8 8 6 8 AA- 10 10 - Thick- 20 20 20 25 30 35 D Only) 15 15 15 20 20 25 C (Minus 10 10 10 15 15 20 B ness 10 10 10 15 15 20 A 10 15 20 11.7 11.7 22 I: I: Continued on Page 24 23 AMERICAN NATIONAL STANDARD HOBS ANSI B94.7-1980 Table 15 Single Thread
15、 Hob Tolerances1 For 30“ P.A. lnvoluts Splines (Continued) (In Ten Thousandths of an Inch) -7 Element - FLUTES Adjacent Flute $;pacing3 Non-Ad- j,acent Flute :;pacing3 Flake to Cutting Depth4 Flute L.ead Ove Cutting Face Width UOLE Hole Diameter Plus Only - NOTE: NORMAL DIAMETRAL PITCH A- A 25 30 50
16、 50 D 15 20 30 30 C 15 20 30 30 B 10 15 20 20 IA- A 80 80 100 100 D 50 50 60 60 C 50 50 60 60 B 30 30 40 40 4A - - A6555 B8777 C8777 D 30 20 20 20 - 8 10 15 15 25 15 30 50 50 80 5 5 7 7 20 - - - - 8 10 15 15 25 15 30 50 50 70 3 3 5 5 15 - _ - 8 10 10 10 20 15 25 40 40 60 3 3 5 5 15 - 86 17 20 20 10
17、10 10 10 10 10 10 10 10 6 15 15 15 25 25 25 40 40 50 60 60 35 40 40 35 33 3 33 3 55 5 55 5 10 10 10 - 6 10 10 10 17 15 20 30 30 40 3 3 5 5 10 - - - - CUTTING FACE WIDTH in inches Up Thru 1 Over 4 Thru 7 Over 2 Thru 4 Over 1 Thru 2 4A 45 3% 23 15 D 30 25 15 10 C 30 25 15 10 B 30 25 15 10 A 25 15 10 -
18、 HOLE DIAMETER in inches 1.250 0.500 and Smaller 0.750 A 3 4 5 D 2 2 3 C 2 2 3 B 2 2 2 A 2 2 2 1. Except for LEAD, these tolerances apply for all hob diameters. For hob diameters larger than those recommended for standard hobs, the LEAD tol- erances shall be increased by a factor of one-half of the percent oversize. 2. Total indicator variation. 3. Compared against master index plate. 4. Radial (zero rake) tooth faces are standard. See Figure 6 for Basic Hob Tooth Form (Page 32) 24
