1、Information on Gear Teeth in Drawings Information on Involute Teeth for Cylindrical Gears In this Standard the information contained in the International Standard IS0 1340 - 1976 has been adopted and supplemented b y additional data. For provisions relating to the representation of gears in drawings
2、 see DIN IS0 2203. This Standard contains only such information as is necessary and adequate, apart from the usual data on material, heat-treatment and hardness, for clearly denoting the involute teeth on a cylindrical gear in manufacturing drawings. If necessary further details may be added, e. g.
3、if the gearcutting or manufacturing method (e. g. injection moulding in the case of plastics gears) to be applied, or agreements on testing and acceptance, make this necessary. For information regarding cylindrical gears for light precision engineering see DIN 58 405 Part 3. The terms, designations
4、and symbols used agree with DIN 3960, DIN 3998 Part 2 and DIN 3999. - DIN 3966 Part 1 Length dimensions in mm O 1 1.1 1.2 1.3 1.4 IF Con ten ts Other relevant Standards. 1 2.2 Page Dimensions and symbols in the drawing . 2 2.3 Tip diameter da 2 3 Root diameter Ctt (if required) 2 4 Symbols of the re
5、ference elements 2 4.1 . Facewidth b . 2 Pnnpnntvipit:, anti .-.mminn tnlnran-n Page Gear tooth tolerances and their test dimensions 3 Gear pairing 4 Data on preparatory treatment. 4 Examples for tables according to Section 2 . 4 Table for an external straight cylindrical 5 . nmar 5 5 7 7 Anwenderin
6、formation Die Originalfassung der Norm enthlt Elemente, z.B. farbige Abbildungen oder Tabellen, die in dieser gescannten Form der Norm nicht originalge- treu darstellbar sind. Dies mu bei der Anwendung bercksichtigt werden. Magebend fr das Anwen- den jeder DIN-Norm ist deren Originalfassung mit dem
7、neuesten Ausgabedatum. Vergewissern Sie sich bitte in den DIN-Mitteilungen, im .aktuellen DIN-Katalog mit dem neuesten Ergnzungsheft oder in der aktuellen Ausgabe der PERINORM. th less nd gear *cal lrm) tion xition; 9s ances, !S 2 to 7 Explanations on page 8 Sole sale rights of German Standards (DiN
8、-Normen) are with Beuth Verlag GmbH, Berlin 30 03.96 DIN 3966 Teil 1 engl. Preisgr. ; Vertr.-Nr. O1 07 UDC 621.833.1 : 744.426 DEUTSCHE NORMEN August 1978 - DIN 3966 Information on Gear Teeth in Drawings Information on Involute Teeth for Cylindrical Gears Part 1 Angaben fr Verzahnungen in Zeichnunge
9、n; Angaben fr Stirnrad- (Zylinderrad-) Evolventenverzahnungen In this Standard the information contained in the International Standard IS0 1340 - 1976 has been adopted and supplemented by additional data. forprovisions relating to the representation of gears in drawings see DIN Is0 2203. This Standa
10、rd contains only such information as is necessary and adequate, apart from the usual data on material, heat-treatment and hardness, for clearly denoting the involute teeth on a cylindrical gear in manufacturing drawings. If necessary further details may be added, e. g. if the gearcutting or manufact
11、uring method (e. g. injection moulding in the case of plastics gears) to be applied, or agreements on testing and acceptance, make this necessary. For information regarding cylindrical gears for light precision engineering see DIN 58 405 Part 3. The terms, designations and symbols used agree with DI
12、N 3960, DIN 3998 Part 2 and DIN 3999. Length dimensions in mm O 1 1.1 1.2 1.3 1.4 1.5 1.6 1.7 2 2.1 Con ten ts 2.2 Page Other relevant Standards. 1 Dimensions and symbols in the drawing , Tip diameter da Root diameter Ctf (if required) . Facewidth b . Symbols of the reference elements Concentricity
13、and camming tolerance as well as parallelism of facesof the gear body . Symbols of surfaces for the tooth flanks to DIN IS0 1302 or DIN 3141 . Denoting the working flanks (if required) 2 2.3 2 3 2 2 4.1 2 4 4.2 4.3 4.4 2 2 Data in separate table 2 4.5 Nominal dimensions of gear teeth . 3 O Other rel
14、evant Standards DIN DIN IS0 1302 Technical drawings; indication of sur- face condition in drawings DIN DIN IS0 2203 Technical drawings; representation of gears DIN 3141 (Preliminary Standard) Surface symbols DIN in drawings; assignment of peak-to-valley DIN heigts DIN 3960 Definitions and parameters
15、 for cylindri- DIN cal gears and cylindrical gear pairs with Page Gear tooth tolerances and their test 3 dimensions Gear pairing 4 Data on preparatory treatment. 4 Examples for tables according to Section 2 . 4 Table for an external straight cylindrical gear . 5 Table for an external helical cylindr
16、ical gear . 5 Table for an internal straight cylindrical gear . 5 Abridged table for an external cylindrical gear . 7 Abridged table for an external cylindrical gear . 7 . 3967 3998 3999 7168 7184 DIN 58 405 involute teeth bases DIN 3961 Tolerances for cylindrical gear teeth; System of gear fits; ba
17、cklash, tooth thickness allowances, tooth thickness to I erances, bases Part 2 Denominations on gears and gear pairs; cylindrical gears and cylindrical gear pairs Symbols for gear teeth Part 2 (at present still in draft form) General tolerances, form and position Part 1 Tolerances of form and positi
18、on; definitions; indications on drawings Part 2 Spur gear drives for fine mechanics; gear fit selection, tolerances, allowances Continued on pages 2 to 7 Explanations on page 8 Sole 8818 rights of German Standards (DiN-Normen) are with Beuth Verlag GmbH, Berlin 30 DIN 3966 Teil 1 engl. Preisgr. 03.9
19、6 Vertr.-Nr. O1 07 Page 2 DIN 3966 Part 1 1 Dimensions and symbols in the drawing I. 1 Tip diameter da Tip diameter da with deviations (if required). N o te : In the case of overcut or injection moulded gears, which by reason of the manufacturing method are to be treated like overcut gears, the conn
20、ection between the tooth thickness allowances and the allow- ances of the tip diameter is to be observed, see DIN 3960. 1.2 Root diameter df (if required), if no tooth depth h is stated in the table. Root diameter df with allowances (if required) if a spe- cific dimension is to be observed. No te :
21、In the case of overcut or injection moulded gears the connection between the tooth thickness allow- ances and the allowances of the root diameter are to be observed, see DIN 3960. 1.3 Facewidth b 1.4 Symbols of the reference elements The reference element for the concentricity and camming tolerancin
22、g is the gear axis. The method of indicating shall be in accordance with DIN 7184 Part 1. 1.5 Concentricity and camming tolerance as well as parallelism of faces of the gear body Where the reference to general tolerances according to DIN 7168 Part 2 is not sufficient, concentricity and camming toler
23、ances to DIN 7184 Part 1 are to be spe- cified. The test locations are to be designated. In detail the following are to be indicated: Permissible concentricity deviation of the external cylinder or of separate cylindrical test surfaces relative Figure 1. Dimensions and symbols in the draw i ng, exte
24、rna I gear teeth with bearing bore to the centre of the borehentre of the journal or rela- tive to the bore envelope/journal envelope; the plane of measurement is to be stated if necessary. Permissible camming deviation of the end faces or of special test surfaces relative to the centre of the boreh
25、entre of the journal or relative to the bore enve- lopefiournal envelope; the measurement circles are to be denoted if necessary. The requirement can be stipu- lated for either one or both sides of the gear. If required (e. g. for gear cutting in clusters) the devia- tions from parallelism of the fa
26、ces is to be toleranced. Remark If required, individual teeth on one side of a gear, which is declared in this way to be the front side, can be de- noted as tooth l and tooth 2, the counting direction being specified at the same time (preferably in the clock- wise direction). The front side is the c
27、riterion for deter- mining the right flank and left flank, see DIN 868. 1.6 Symbols of surfaces for the tooth flanks to DIN IS0 1302 or DIN 3141, if necessary also for the tooth root and root radiusing surfaces. 1.7 Denoting the working flanks (if required) e. g. by the note “working flank“ in a tra
28、nsverse section, see DI N 868. 2 Data in separate table In a table those parameters are to be stated which are necessary, for the particular case concerned, for select- ing or manufacturing the tool producing the gear teeth (e. g. pinion type cutter, injection mould), for setting the gear tooth prod
29、uction machine and for testing the gear teeth. 4 -t Figure 2. Dimensions and symbols in the drawing, Figure 3. Dimensions and external gear teeth with journal symbols in the drawing, internal teeth DIN 3966 Part 1 Page 3 T In the heading of the Table it shall be stated whether the data apply to an e
30、xternal or an internal cylindrical gear. The Table may either be incorporated in the drawing sheet or attached to the drawing as a separate sheet. The examples in Sections 4.1 to 4.3 show a detailed form of the Table with all the necessary data. It may be appro- priate to provide on the drawing abri
31、dged tables contain- ing only a few items of data, see examples in Sections 4.4 and 4.5. The data lacking in these tables, but neces- sary for describing the gear teeth, can then be supplied as a separate sheet accompanying the drawing. 2.1 Nominal dimensions of gear teeth 2.1.1 Module m The normal
32、module m, is to be stated. 2.1.2 Number of teeth z For the purpose of calculations, the number of teeth of an external gear is given a positive sign and the number of teeth of an internal gear a negative sign, see DIN 3960. In drawings the number of teeth is always stated without sign. If the gear t
33、eeth on the workpiece consist only of one or more sectors, the number of teeth of the complete tooth system shall be stated in the table, and additionally in brackets (optionally in the table or drawing) the number of teeth of the sectors. 2.1.3 Standard basic rack tooth profiles 2.1.3.1 Standard ba
34、sic rack tooth profile of the gear teeth Remark In the case of helical gears the standard basic rack tooth profile applies to the normal section. N o t e : The gear tooth tolerances for involute teeth with normal standard basic rack tooth profile (see DIN 396 1 to DIN 3967 or DIN 58 405 Part 2) can
35、also be used as appropriate for gear teeth the standard basic rack tooth profile of which deviates in one or more para- meters from DIN 867 or DIN 58 400, e. g. in the profile angle a, the tooth depth h, the bottom clearance etc., or for which certain profile modifications are specified. The paramet
36、ers subject to deviation are to be specially stated, preferably in a drawing. 2.1.3.2 S t a n d a r d t o o I p r o f i I e The standard tool profile is stated according to DIN 3972 or DIN 58 412 or in a drawing. 2.1.4 Helix angle The helix angle /3 is stated without sign, see DIN 3960. If a helix a
37、ngle to DIN 3978 is used, then “DIN 3978“ shall be added to the dimension data. It may be expedient to state also the number of teeth of the pinion type cutter and the helical guidance lead, see example in Section 4.2. N o t e : This applies in particular when a helix angle not contained in DIN 3978
38、 is specified with a non- standard number of teeth on the pinion cutter but with standard helicalguidance lead (see Explanations in DIN 3978). 2.1.5 Flank direction (of helical gears) Instead of the terms “right-handed“ or “left-handed“ to DIN 3960 it is sufficient to state “right“ or “left“ or “R“
39、or “L“ in the table. In the case of double helical teeth and continuous double helical teeth the corresponding symbols to DIN IS0 2203 are to be used and supplemented as necessary by any further data needed. 2.1.6 Reference circle diameter d and base diameter db N o t e : The reference circle diamet
40、er d derives from the foregoing gear tooth data. It is not needed for gener. ating and testing the teeth and can therefore be omitted from the table. The base diameter can be omitted if it is not needed for generating or testing the teeth. 2.1.7 Addendum modification coefficient x The addendum modif
41、ication coefficient x is to be stated with its sign “+“ or “-“, see DIN 3960. N o t e : In the table the theoretical value of the adden- dum modification coefficient is to be stated without tak- ing into account the tooth thickness allowances not even if these, as is usually the case, are produced b
42、y an addi- tional depth feed of the gearcutting tool. With this theoretical value it is possible to check the nominal dimensions of the tip diameter, base tangent length etc. more quickly than if it were first necessary to determine a proportion assignable to the production of the tooth thickness al
43、lowances and deduct this. Remark For internal gears the sign of the addendum modification has been altered in DIN 3960, October 1976 edition, compared with the previous editions. In the case of inter- nal gears it is recommended that a note drawing attention to the new provision should be included i
44、n the table, see example in Section 4.3. N o t e : In contrast with the provision of this Section, that the addendum modification coefficient is to be stated with its sign, the negative signs of the number of teeth, the diameter, the centre distance and some test dimen- sions for the tooth thickness
45、 requiring to be used, or arising, in connection with the calculation of internal gears are not generally stated in production documents intended for the workshop, see also DIN 3960 and DIN 3993. 2.1.8 Tooth depth h The parameter stated is the nominal dimension of the tooth depth h, which also conta
46、ins the addendum alter- ation h m, so that the nominal dimension of the root diameter can be calculated from the tip diameter in the drawing and the tooth depth h. 2.1.9 Addendum alteration k . m, This information is usually only necessary if it is not certain in advance what tool addendum ha0 will
47、be used for cutting the teeth, or if the tip cylinder will be overcut with a standard cutting tool. This applies also to injection moulded gears. 2.2 Gear tooth tolerances and their test dimensions N o t e : The information according to Sections 2.2.1 to 22.6 characterizes the quality of the gear te
48、eth and Page 4 DIN 3966 Part 1 their acceptance testing. The information is sufficient for finding all the necessary numerical values in the Standards DIN 3962, DIN 3963 and DIN 3967. It is optional whether the provisions of these Sections are supplemented in the Table by additional data according t
49、o Section 22.7, see examples in Sections 4. I to 4.3. 2.2.1 Gear tooth quality, tolerance zone Data according to DIN 3961 and DIN 3967 or accord- ing to DIN 58 405 Part 2. 2.2.2 Quality testing and test groups N o t e I When determining the gear tooth quality by stating function groups it is not absolutely necessary for all the parameters and working deviations belonging to this group to be tested; it is sufficient to test only those parameters or working deviations which are critical for the case concerned. For a certain function group and gear tooth quality, therefore, test
