1、BRITISH STANDARD BS 4656-25: 1980 Specification for The accuracy of machine tools and methods of test Part 25: Gear planing machines UDC 621.9.01187.001.4:621.833.002.2:621.912BS4656-25:1980 This British Standard, having been prepared under the directionof the Mechanical Engineering Standards Commit
2、tee, was published underthe authority of the Executive Board on 30 April1980 BSI 10-1999 The following BSI references relate to the work on this standard: Committee reference MEE/6 Draft for comment 78/76910 DC ISBN 0 580 11328 0 Cooperating organizations The Mechanical Engineering Standards Committ
3、ee, under whose direction this British Standard was prepared, consists of representatives from the following Government departments and scientific and industrial organizations: Associated Offices Technical Committee Department of the Environment Association of Consulting Engineers Department of Trad
4、e (Marine Division) Association of Hydraulic Equipment Engineering Equipment Users Association Manufacturers Federation of Manufacturers of Construction Association of Mining Electrical and Equipment and Cranes Mechanical Engineers Health and Safety Executive British Compressed Air Society Instituti
5、on of Gas Engineers British Electrical and Allied Manufacturers Institution of Mechanical Engineers* Association (BEAMA) Institution of Plant Engineers British Gas Corporation Institution of Production Engineers* British Gear Manufacturers Association London Transport Executive British Internal Comb
6、ustion Engine Ministry of Defence* Manufacturers Association National Coal Board British Pump Manufacturers Association Oil Companies Materials Association British Steel Corporation Process Plant Association British Steel Industry Railway Industry Association of Great Britain Chartered Institution o
7、f Building Services Society of Motor Manufacturers and Traders Crown Agents for Oversea Governments and Limited Administrations Telecommunication Engineering and Department of Industry (Mechanical Manufacturing Association (TEMA) Engineering)* Water-tube Boilermakers Association Department of Indust
8、ry (National Engineering Laboratory) The organizations marked with an asterisk in the above list, together with the following, were directly represented on the committee entrusted with the preparation of this British Standard: Ball and Roller Bearing Manufacturers Machine Tool Industry Research Asso
9、ciation Association University of Aston in Birmingham Department of the Environment (PSA) University of Manchester (Institute of Federation of British Engineers Tool Science and Technology) Manufacturers Individual experts Amendments issued since publication Amd. No. Date of issue CommentsBS4656-25:
10、1980 BSI 10-1999 i Contents Page Cooperating organizations Inside front cover Foreword ii 1 Scope 1 2 References 1 3 Application of test methods 1 4 Abbreviations 1 5 Diagrams 1 6 Practical tests 1 7 Accuracy of work spindle indexing worm and worm wheel 2 Table 1 Tolerances on test gear blanks 2 Tab
11、le 2 Geometrical tests and accuracy requirements for gear planing machines 3 Publications referred to Inside back coverBS4656-25:1980 ii BSI 10-1999 Foreword This Part of this British Standard has been prepared under the direction of the Mechanical Engineering Standards Committee. It has been develo
12、ped following consideration of an initial proposal prepared by the Machine Tool Trades Association for the revision of BS3329:1961 “Specification for gear planing and shaping machines”. For convenience it was decided to produce the revision of BS3329 in two Parts, one dealing with gear planing machi
13、nes, and one dealing with gear shaping machines. BS 3329:1961 has now been withdrawn. The format of the standard has been revised to accord with that of the general series of standards dealing with machine tool tests known as the BS4656 series. A British Standard does not purport to include all the
14、necessary provisions of a contract. Users 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, pagesi andii, pag
15、es1 to8, an inside back cover and 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.BS4656-25:1980 BSI 10-1999 1 1 Scope This Part of this British Standard specifies, wit
16、h reference to BS3800, both geometrical and practical tests for gear planing machines used for the production of external spur and helical gears and splined shafts, and gives corresponding permissible deviations which apply. This standard is applicable to machines of general purpose use and normal a
17、ccuracy. It deals only with the verification of accuracy of the machine. It does not apply to the testing of the running of the machine (vibrations, abnormal noises, stick-slip motion of components etc.) nor to its characteristics (speeds, feeds etc.) which should generally be checked before testing
18、 accuracy. 2 References The titles of the publications referred to in this standard are listed on the inside back cover. 3 Application of test methods 3.1 In applying the tests detailed in Table 2, reference should be made to BS3800, especially concerning the installation of the machine before testi
19、ng, warming-up of spindles and other moving parts, the description of measuring methods and the recommended accuracy of testing equipment. 3.2 The tests may be applied in any order that is practicable and that makes for ease of mounting of instruments or gauging. The sequence in which the geometrica
20、l tests are listed in Table 2 is related to the sub-assemblies of the machine and it is not intended to impose the practical order in which the tests are to be done. 3.3 When inspecting a gear planing machine, it is necessary to carry out all the tests specified in this standard, where applicable. 3
21、.4 When establishing the tolerance for a measuring range different from that given in this standard (see2.311 of BS3800:1964), it should be taken into consideration that the minimum value of tolerance is0.001mm for geometrical and practical tests. 4 Abbreviations For the purposes of this standard, v
22、arious methods of expressing permissible deviations are employed, each having a particular type of application. The methods employed are as follows. 5 Diagrams For reasons of simplicity the diagrams in this standard illustrate only one type of machine. 6 Practical test 6.1 General 6.1.1 Object of te
23、st. The object of this test is to verify the geometry of the machine by cutting a test piece under lightly loaded conditions. 6.1.2 Spur gears. A test spur gear shall be cut for one specified direction of rotation of the table or work spindle and measured for pitch and tooth alignment errors. If cut
24、ting in both directions is required, this is subject to special arrangement between the purchaser and the manufacturer. - - - / - - - This type of expression applies to deviations of perpendicularity that are ratios. - - - for any length of - - This type of expression applies to deviations of straig
25、htness and parallelism, and is used in fact for local permissible deviations, the measurement length being obligatory. - - - per - - - This type of expression applies to deviations of straightness and parallelism and is used to recommend a measurement length, but in this case the proportionality rul
26、e comes into operation if the measurement length differs from that indicated.BS4656-25:1980 2 BSI 10-1999 6.1.3 Helical gears. If the machine is required for cutting helical gears, an additional test gear with helical teeth shall be cut for one specified direction of rotation and measured for helix
27、angle, lead or axial pitch. If cutting in both directions is required, this is subject to special arrangement between the purchaser and the manufacturer. 6.1.4 Diameter of test gear. The diameter of the test gear shall be equivalent to at least30%, unless otherwise agreed, of the capacity of the mac
28、hine and the face width of the test gear blank shall be equivalent to at least20% of the capacity of the machine for width. 6.1.5 Accuracy requirements for test gears. Test gears shall comply with the following requirements of BS436-2. Adjacent and cumulative pitch tolerance: grade7, BS436-2. 3.55+9
29、.04m where l = any selected length of arc (in mm) less than ;d/2. Alignment of tooth tolerance: grade7, BS436-2 1.25+6.34m Tolerances on tooth alignment are related to a proportion or to the whole of the face width b (inmm) of the gear and apply up to a maximum ofb =150mm. NOTEThere is only limited
30、data available on which to base tolerances for gears of greater face width than150mm, for which (as with all gears) the ultimate test is accuracy of meshing. The above formulae are taken from BS436-2. 6.2 Blank requirements and cutting requirements The manufacturer shall select the test gear materia
31、l, cutter and cutting data in such a manner that the surface texture generated is satisfactory for measuring purposes. The test gear shall, at the discretion of the manufacturer, be produced employing light finishing cuts. It is recommended that a cutter complying with the requirements of grade A of
32、 BS2697 should be used to cut test gears. The accuracy of the test gear blank shall be consistent with the grade of gear as specified in BS436-2 and as reproduced in Table 1. Table 1 Tolerances on test gear blanks 7 Accuracy of workspindle indexing worm and wormwheel 7.1 General. The workspindle wor
33、m and wormwheel should comply with the following requirements. a) Wormwheel. Adjacent and cumulative pitch tolerance: 1.25+3.3 4m where l is any selected length of arc (in millimetres) less than D/2. b) Worm. Adjacent pitch tolerance:0.010mm. Cumulative pitch tolerance over any five pitches:0.025mm.
34、 c) Cyclic error. The average cyclic error for each separate flank shall not exceed0.008. Local departures from uniformity within any convolution shall not exceed a total range of0.010. The cyclic error of the main worm is the total range of difference in any convolution in a direction parallel to t
35、he axis between the position of the actual helix and a true helix having a lead equal to the lead of that convolution. 7.2 General procedure for measurement of cyclic error. Readings shall be taken on each flank separately at approximately mid-depth and continued for at least three convolutions of t
36、he worm near the middle of the worm face and for not less than six equally angular positions in each of these convolutions. l b All values in micrometres (4m) except tip diameter d ain millimetres. Characteristic Tolerances for grade7 gear Bore size tolerance a IT7 b Shaft size tolerance a IT6 b Rad
37、ial runout of tip cylinder 0.025d a +15 Radial runout of reference surface Axial runout of reference surface Blank diameter IT8 a Where the tip cylinder (blank diameter) is used as a datum for a checking instrument. b The IT values are the internationally agreed fundamental tolerances of BS4500-1 to
38、 which reference should be made.l BS 4656-25:1980 BSI 10-1999 3 Table 2 Geometrical tests and accuracy requirements for gear planing machines All dimensions are in millimetres. 1 2 3 4 5 6 No. Diagram Object Permissible deviations Measuring instruments Observations and references to thetestcode BS38
39、00 G1 Checking of the levelling of the slideways: a) longitudinally; b) transversely. a) 0.050per300 b) 0.050per300 Precision level and straightedge a) Shall be inclined in one direction without hollows and humps. NOTEThis test should only be carried out when instructions on levelling have not been
40、provided by the manufacturer. G2 Run-out of location bore of spindle: a) adjacent to the spindlenose; b) at a distance of300 from spindle nose. a) 0.01FIM b) 0.03FIM (fullindicator movement) Dial gauge and test mandrel 5.6.12.3 Test to be made in both horizontal and vertical plane.BS 4656-25:1980 4
41、BSI 10-1999 Table 2 Geometrical tests and accuracy requirements for gear planing machines All dimensions are in millimetres. 1 2 3 4 5 6 No. Diagram Object Permissible deviations Measuring instruments Observations and references to the testcode BS3800 G3 Checking the coincidence of the axis of the o
42、uter support with the axis of the spindle: a) in the horizontal plane; b) in the vertical plane. a) 0.02per300 b) 0.02per300 Dial gauge and test mandrel 5.442 First check that test bar is set to mean position before checking outer support G4 Checking of periodic axial slip of spindle. 0.006 Dial gau
43、ge 5.622.1 and 5.622.2 Measured over steel ball on spindle centre. Force, F, applied to spindle in both directions. Force, F, is to be specified by manufacturer.BS 4656-25:1980 BSI 10-1999 5 Table 2 Geometrical tests and accuracy requirements for gear planing machines All dimensions are in millimetr
44、es. 1 2 3 4 5 6 No. Diagram Object Permissible deviations Measuring instruments Observations and references to the test code BS3800 G5 Measurement of camming of the external register face of workspindle nose. 0.01per150 rad Dial gauge 5.632 Dial gauge to be mounted on any fixed face. Measurements to
45、 be taken at largest radius possible. G6 Checking of parallelism of the movement of the cutter head to the spindle face. 0.02per300 Dial gauge and straightedge 5.422.3 Fix straightedge to face of spindle. Dial gauge to be mounted on cutter head. Optimize spindle position (toallow for camming).BS 465
46、6-25:1980 6 BSI 10-1999 Table 2 Geometrical tests and accuracy requirements for gear planing machines All dimensions are in millimetres. 1 2 3 4 5 6 No. Diagram Object Permissible deviations Measuring instruments Observations and references to the test code BS3800 G7 Checking cutter box and cutter h
47、ead for: a) squareness of cutter box slot to spindle axis; b) parallelism of cutter box vertical movement to spindle (arbor); c) parallelism of cutter head horizontal movement to locating face of cutter. a) 0.02per300 b) 0.01per100 c) 0.01per100 Dial gauge, test mandrel and straightedge a) 5.512.2 a
48、nd 5.512.42 b) 5.232.1 c) 5.522.2 With dial gauge fixed to arbor. Straightedge fixed in the cutter box slot and located against bottom and side datum faces of box. a) Rotate arbor to check squareness of slot. b) With arbor stationary, traverse slide through vertical movement. c) Traverse cutter head
49、 horizontally. G8 Checking parallelism of the back face of the cutter box slot to the cutter box movement. 0.1per100 Dial gauge 5.412.4BS 4656-25:1980 BSI 10-1999 7 Table 2 Geometrical tests and accuracy requirements for gear planing machines All dimensions are in millimetres. 1 2 3 4 5 6 No. Diagram Object Permissible deviations Measuring instruments Observations and references to the test code BS3800 G9 For spur machines only Checking parallelism of cutter slide movement to workspindle axis (arbor): a) in the vertical plane; b) in the horizonta
