1、April 2010 English price group 12No part of this translation may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS 21.200!$HP“1933745www.din.deDDIN 3
2、970Master gears for checking cylindrical gears Gear blanks and gearing,English translation of DIN 3970:2010-04Lehrzahnrder zum Prfen von Zylinderrdern Radkrper und Verzahnung,Englische bersetzung von DIN 3970:2010-04Pignons-talons pour la vrification des roues cylindriques Corps de roue et denture,T
3、raduction anglaise de DIN 3970:2010-04SupersedesDIN 3970-1:1974-11 andDIN 3970-2:1974-11www.beuth.deDocument comprises 23 pages01.14Translation by DIN-Sprachendienst.In case of doubt, the German-language original shall be considered authoritative.DIN 3970:2010-04 2 A comma is used as the decimal mar
4、ker. Contents Page 1 Scope 5 2 Normative references 5 3 Master gear applications . 5 4 Symbols, subscripts and units . 6 5 Dimensions . 7 5.1 Gear body . 7 5.2 Centre hole diameter, D1. 8 5.3 Axial runout of the gear face and radial runout of the clocking bend . 9 6 Geometry 10 6.1 Design . 10 6.2 N
5、umber of teeth, z 10 6.3 Tooth thickness, sn11 6.4 Tooth system edge finish . 11 6.5 Tip diameter, da13 6.6 Active tip diameter, dNa. 13 6.7 Root form diameter, dFf13 6.8 Root diameter, df13 6.9 Modifications 13 7 Tolerances 14 7.1 Tolerances of deviations . 14 7.2 Special pressure angles 16 8 Mater
6、ial . 16 9 Technical drawings of master gears 17 10 Marking and designation 17 11 Ordering information . 19 12 Quality inspection 20 12.1 Test certificate 20 12.2 Measurement equipment requirements 20 12.3 Evaluation of tooth system measurements 20 13 Wear inspection and re-working 21 14 Packaging,
7、storage and handling 21 15 Master gears not conforming to all individual specifications of this standard 21 15.1 Special designs 21 15.2 Centre hole diameter, D1. 21 Annex A (informative) Some examples of standard numbers of teeth . 22 Bibliography 23 DIN 3970:2010-04 3 Page Figures Figure 1 Master
8、gear, sizes 1 to 5 8 Figure 2 Master gear, sizes 6 to 8 8 Figure 3 Designation of tooth edges . 12 Figure 4 Tooth profile with a tip edge chamfer, cross-section of tooth system . 12 Figure 5 Location of marking on master gears 17 Figure 6 Marking on tooth number 1 of master gears of sizes 1 to 4 . 1
9、7 Figure 7 Marking and designation of master gears . 19 Tables Table 1 Master gear body dimensions. 7 Table 2 Permissible dimensional deviations and form deviations for the centre hole 9 Table 3 Permissible relative positional deviations of master gears from the axis A of the centre hole 9 Table 4 R
10、ecommended tooth thickness tolerances . 11 Table 5 Quality parameters for master gear accuracy classes A, B and C . 14 Table 6 Tolerances of deviations F, fp, Fp, Frfor accuracy class A 15 Table 7 Tolerances of deviations F, fp, Fp, Frfor accuracy class B 15 Table 8 Tolerances of deviations F, fp, F
11、p, Frfor accuracy class C 15 Table 9 Tolerances of total helix deviation Ffor accuracy classes A, B and C 16 Table A.1 Examples of standard numbers of teeth 22 DIN 3970:2010-04 4 Foreword Master gears are used for single-flank and double-flank rolling testing of gears. The design of master gears for
12、 double-flank testing is only partially described in the standard DIN 3970 Parts 1 and 2:1974-11 and the description is incomplete. The 1974 editions of these two standards have been applicable since 1974 and have not been revised since then. In the meantime, however, there have been considerable te
13、chnological changes and these are either inadequately covered by the old editions of the standards or are not covered by them at all. The tangential composite inspection and radial composite inspection of gears are described in VDI/VDE Guideline 2608, which also deals with master gears to a limited
14、extent. The definitions given in this standard can also be applied to master gears intended for use in other test procedures (e.g. noise tests, runout tests etc.). The DIN Standards which correspond to the International Standards referred to in Clause 2 and in the Bibliography of this document are a
15、s follows: ISO 13281-1 is similar to DIN 3961:1978, DIN 3962-1:1978, DIN 3962-2:1978 and DIN 3963:1978 ISO 21771 see DIN ISO 21771 Amendments This standard differs from DIN 3970-1:1974-11 and DIN 3970-2:1974-11 as follows: a) the term “gears” (Stirnrder) has been replaced by “cylindrical gears” (Zyl
16、inderrder); b) the scope of application has been extended to include a module mnof 0,2 mm to 12 mm; c) the values for external dimensions of small modules have been taken over from DIN 58420 and have been revised; d) test collars have been introduced for all master gears; e) the number of teeth, too
17、th thicknesses and addenda have been modified and recalculated; f) tooth thickness tolerances have been introduced for master gears; g) specifications for the finish and shape of edges have been added; h) tooth flank modifications, such as different helix angles, have been introduced; i) accuracy cl
18、asses A, B and C have been introduced; j) specifications for dealing with pressure angles n 20 have been added; k) drawing specifications have been added; l) quality verification specifications have been added; m) the wear limit definition has been added; n) rules for reworking have been introduced.
19、 Previous editions DIN 3970-1: 1967-08, 1974-11 DIN 3970-2: 1967-08, 1974-11 DIN 3970:2010-04 5 1 Scope This standard applies to spur master gears and helical master gears used to check cylindrical gears with involute tooth systems of normal modules mnranging from 0,2 mm to 12 mm and helix angles of
20、 up to 45. 2 Normative references The following referenced documents are indispensable for application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. DIN 867, Basic rack
21、 tooth profiles for involute teeth of cylindrical gears for general engineering and heavy engineering DIN 3962-1, Tolerances for cylindrical gear teeth Part 1: Tolerances for deviations of individual parameters DIN 3963, Tolerances for cylindrical gear teeth Tolerances for working deviations DIN 397
22、0-2, Master gears for checking spur gears Part 2: Receiving arbors DIN ISO 2768-1, General tolerances Part 1: Tolerances for linear and angular dimensions without individual tolerance indications*)DIN ISO 18653, Gears Evaluation of instruments for the measurement of individual gears ISO 1328-1, Cyli
23、ndrical gears ISO system of flank tolerance classification Part 1: Definitions and allowable values of deviations relevant to corresponding flanks of gear teeth VDI/VDE 2607, Computer-aided evaluation of profile and helix measurements on cylindrical gears with involute profile VDI/VDE 2613, Pitch an
24、d runout testing on gearings Cylindrical gears, worm wheels, bevel gears 3 Master gear applications Master gears are gears with known properties and are preferably used to determine cumulative and total deviations of other gears or racks (single- or double-flank rolling tests). They are also used to
25、 verify gear measuring equipment. *)Translators note. Not cited in this standard. DIN 3970:2010-04 6 4 Symbols, subscripts and units The following symbols and abbreviations for equations, designations and units are used in this standard: Symbols Designation Unit b width mm d reference diameter mm da
26、tip diameter mm daztip diameter used to calculate the number of teeth mm dbbase diameter mm dfroot diameter mm dFfroot form diameter mm dNaactive tip diameter mm dNfstart of active profile diameter (SAP diameter, active root diameter) mm fpindividual pitch deviation m mnnormal module mm snnormal too
27、th thickness mm z number of teeth Astooth thickness tolerance field m D diameter mm Ftotal profile deviation m Ftotal helix deviation m Fndeviation in “new” condition m Fptotal pitch deviation m Frrunout (radial) m Fvdeviation in “used” condition m MdKdimension over two balls mm MrKradial single-bal
28、l dimension mm Rstooth thickness variation m Tstooth thickness tolerance m Y1 radial runout of test collar m Y2 face runout m nnormal pressure angle helix angle DIN 3970:2010-04 7 5 Dimensions 5.1 Gear body Master gears are preferably designed for a specific application. The tooth system width of ma
29、ster gears should be 2 to 4 mm*)greater than the width of the gears being tested. In some applications it may be necessary to only test the tooth system quality within the effective tooth width of the gear being tested. In such cases the user and the supplier shall reach an agreement on the tooth sy
30、stem width of the master gear. If no requirements are specified with regard to the tooth system width or test width of the gear being tested, the widths b1 and b2 as listed in Table 1 shall be used. Eight master gear sizes are defined for modules in the range of 0,2 mm to 12 mm, see Table 1. Table 1
31、 Master gear body dimensions Master gear size Module mn mm D1aD2D3D4dazbb1cb2cb3b4b5over up to mm mm mm mm mm mm mm mm mm mm 1 0,2 0,35 12 df 2 25 10 30 1 2 0,35 0,55 16 df 3 36 10 30 1 3 0,55 1,2 22 df 5 50 13 30 1 4 1,2 2 32 50 df 5 85 17 33 1 0,5 5 2 3,5 32 60 df 10 125 23 36 2 1 6 3,5 5,5 45 70
32、df 10 df 30 170 30 43 2 1 12 7 5,5 8 45 70 df 10 df 30 220 42 56 3 1 18 8 8 12 60 90 df 10 df 40 280 60 74 3 1 28 aSee 5.2 for permissible dimensional and form deviations of the centre hole. bThe tip diameter daz is simply a dimension that has been defined as a basis for calculating the number of te
33、eth using Equation (1). The actual tip diameter daof the master gear is calculated in the manner described in 6.5 and 6.6. It may differ considerably from daz.cThese dimensions apply when the tooth system width or test width of the gear being tested is not specified. Master gears shall always be man
34、ufactured with a clocking bend. The individual dimensions of master gears are shown in Figures 1 and 2. *)Translators note. The original German text (2 mm 4 mm) is incorrect. DIN 3970:2010-04 8 Figure 1 Master gear, sizes 1 to 5 Figure 2 Master gear, sizes 6 to 8 5.2 Centre hole diameter, D1The perm
35、issible dimensional and form deviations for the centre hole diameter D1are listed in Table 2. They do not apply to the outer 5 % of the hole length at either end of the hub. In these sections, it is permissible for the hole diameter to be larger, but not smaller than the given values. The tolerance
36、ranges stated in Table 2 relate to the standardized master gear width b2. DIN 3970:2010-04 9 Table 2 Permissible dimensional deviations and form deviations for the centre hole Master gear size Hole diameter D1mm Hole diameter tolerance D1Runout tolerance Straightness tolerance of the cylinder surfac
37、e line Parallelism tolerance of the cylinder surface line m m m m new (H4) wear limit new wear limit new wear limit new wear limit 1 12 +5 +6,5 1,5 2,5 1,5 2,5 2 3,5 2 16 +5 +6,5 1,5 2,5 1,5 2,5 2 3,5 3 22 +6 +7,5 1,5 2,5 1,5 2,5 2 3,5 4, 5 32 +7 +9 2 3,5 2 3 3 4 6, 7 45 +7 +9 2 3,5 2 3,5 3 4,5 8 60
38、 +8 +10 2 3,5 2 3,5 3 4,5 5.3 Axial runout of the gear face and radial runout of the clocking bend The axial runout of the gear face shall be measured within a circle of diameter D2on reference face B. Irrespective of the intended use of the master gear (fixed or rotating on the arbor), the axial ru
39、nout is measured with the gear fixed on the arbor (see DIN 3970-2). Before the axial runout is measured, the radial runout of the mounting arbor shall be checked on both sides of the master gear. Permissible axial and radial runout values are listed in Table 3. Table 3 Permissible relative positiona
40、l deviations of master gears from the axis A of the centre hole Master gear size 1 2 3 4 5 6 7 8 Radial runout of test collar Y1a), m 3 3 3 3 3 3 3 4 Axial runout Y2a), m 2 2 2 2 2 2 3 3 a)See Figures 1 and 2. DIN 3970:2010-04 10 6 Geometry 6.1 Design The master gear is normally designed to match th
41、e gear being tested. Subject to agreement, the master gear can be designed to fit a defined reference profile (e.g. as specified in DIN 867). Since their design is limited to specific types of gear, master gears should preferably be designed unmodified (without addendum modification). In most cases,
42、 it is possible to test and inspect the entire active profile of a gear by producing master gears with various addendum heights. A “V” (modified) tooth system (with addendum modification) should be avoided as far as possible. However, master gears are to be designed with a “V” (modified) tooth syste
43、m if, for an unmodified tooth system, it would: mean that the working pressure angle differs considerably from the nominal working pressure angle of the gear being tested; cause the working profile range of the master gear to extend almost to the base circle, see 6.7; be impossible to provide suffic
44、ient tip clearance to the root of the teeth of the matching gear, and be impossible to re-grind the tooth system as often as required. In all cases, the master gear is to be designed to ensure trouble-free testing and inspection of the respective gears. 6.2 Number of teeth, z The number of teeth of
45、a master gear of a given size is calculated on the basis of the normal module and the helix angle. In order to facilitate tip diameter measurements, only even numbers of teeth shall be specified. The maximum possible number of teeth zmaxfor a given gear size is calculated using the normal module mn,
46、the tip diameter dazas listed in Table 1 for the corresponding normal module mnand the helix angle . The following equation is to be used: nnazmaxcos)2(mmdz= (1) Normally, the resulting value of the maximum possible number of teeth zmaxis not an integer. In order to reduce the number of teeth to a f
47、easible value, if the calculated value of zmaxis less than 48, it is rounded down to the nearest number that is divisible by 2, and if the calculated value is greater than 48, it is rounded down to the nearest number that is divisible by 4 (see Table A.1 for examples). The numbers of teeth determine
48、d by Equation (1) also apply to master gears with addendum heights that differ from those specified in DIN 867. There are therefore some boundary cases in which dawill be greater than daz. Master gears with numbers of teeth deviating from the results described above are considered to be special desi
49、gns. If, for instance, more or fewer teeth are required, then the gear size which would have the fewest deviations from this standard should be selected. Subject to agreement, the number of teeth of the master gear can be a prime number or a number which has no common divisor (common factor) with the number of teeth of the gears to be tested. DIN 3970:2010-04 11 6.3 Tooth thickness, snThe tooth thickness of master gears s
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