1、UDC 621.825.7 : 003.62 Power transmission engineering Fi ex bi e shaft cou pi i ngs Tech ni cal de I ive ry conditions DEUTSCHE NORM DIN 740 Part 1 August 1986 Antriebstechnik; nachgiebige Wellenkupplungen; technische Liefer- bedingungen Supersedes March 1975 edition. In keeping with current practic
2、e in standards published by the International Organization for Standardization (/SO), a comma has been used throughout as the decimal marker. Contents 1 Scope and field of application . 1 4.7 Surface finish . 8 3 Designation . i 4.9 Requirements to be met by Page Page 4.8 Requirements to be met by c
3、ast coupling components 2 Concepts. 1 forged coupling components 8 3.1 General . . . 1 3 4.10 Balancing . 8 3.2 Forms . 3.3 Examples of standard designat 5 4.11 Alignment faces . 8 4.1 2 Printed information . 8 4 Technical delivery conditions 5 4.1 3 Details to be aiven nas 11 4.1 4.2 4.3 4.4 4.5 4.
4、6 .+ I Calculation 5 4.14 Reduction of number of types,. 13 Design 5 4.15 Materials testing certificates . 13 Manufacturing process and materials . 6 4.16 Other requirements 13 13 13 Heat treatment 6 Wear reduction 6 5 Marking . Dimensional and geometrical tolerances 7 6 Operating instruction manual
5、 . 1 Scope and field of application Flexible shafl couplings as covered in this standard are used within the field of power transmission engineering. The specifications given in this standard may also be applied by analogy to rigid shaft couplings. The technical requirements to be met by the design
6、and manufactureof flexible shaft couplings have been summarized in the present standard to permit assessment according to uniform principles. In particular, this standard is intended to be applied as a technical delivery condition for when ordering coupling forms and materials, and to increase the r
7、eliability of flexible shaft couplings. 2 Concepts For the purpose of this standard, flexible shaft couplings are non-slip couplings of axially, radially and angularly flexible design, which may be either torsionally flexible or rigid. Torsionally flexible couplings are understood to mean couplings
8、incorporating flexible rubber and flexible metal elements. See VDI 2240 for the classification of shaft couplings according to their properties. 3 Designation All the details required for the designation of a flexible shaft coupling have been specified in sub- clauses 3.1 to 3.3. Further particulars
9、 shall be subject to agreement. 3.1 General See table 1 for quantities and symbols. This table is designed to ensure uniform use of the symbols cover- ing the entire range of flexible shaft couplings, with and without brake disc or brake drum. Continued on pages 2 to 5 uth Verlag GmbH, Berlin. has t
10、he exclusive right of sale for German Standards (DIN-Normen). DIN 740 Part 1 Eng/. Price group . Sales No. O111 01 .a8 Page 2 DIN 740 Part 1 Table 1. Quantities and symbols Quantity See figures width of brake drum as specified in DIN 15431 2,3, 6 and 7 width of brake disc as specified in DIN 15432 (
11、at present at the stage of draft) 4 and 8 external diameter of brake drum as specified in DIN 15431 and DIN 15435 Part 1 2,3, 6 and 7 effective mean friction diameter of brake disc as specified in DIN 15433 Part 1 (at present at the stage of draft) 4 and 8 external diameter of brake disc as specifie
12、d in DIN 15432 4 and 8 internal diameter of brake disc as specified in DIN 15432 4 and 8 cylindrical bore in the left coupling hub or maximum bore diameter in the case of a tapered bore 1 to 4,9 and 10 1 to 4,9 to 11 cylindrical bore in the right coupling hub or maximum bore diameter in the case of
13、a tapered bore maximum diameter of metallic coupling flange 1, 2, 4 to 11. and 13 diameter of counterbore in the right coupling hub 1 to 4,9 to 11 1 to 4, 9 and 10 diameter of counterbore in the left coupling hub maximum diameter of elastic element made of elastomeric material (only relevant if g is
14、 larger than d6) 5 to 8,10,13 and 14 maximum diameter of the left flange 11 to 14 pitch circle diameter of the left flange 11 to 14 maximum diameter of the right flange 12 and 14 pitch circle diameter of the right flange overall length of coupling In the case of axially flexible couplings, the overa
15、ll length is equal to Z1 = Il ,in + A Ka. length of left coupling hub 12 and 14 1 to 14 1 to 10 length of right coupling hub 1 to 11 and 13 length of d4 hub bore length of d5 hub bore 1 to 4,9 and 10 1 to 4, 9 to 11 Distance between coupling hubs; it is given by: s1 and s1 = Il - (Z2 + Z3) = s1 + A
16、Ka with ,in = SI -A Ka 1 to 14 Distance between shaft ends if the shaft end faces lie flush with the faces of the counterbores (d7 and de) in the axial direction s2 and s2 = Il - (Z4 + 15) = s2 + A Ka with S2min = sp - A Ka Number of bolts X thread diameter for left flange 11 to 14 Number of bolts X
17、 thread diameter for right flange 12 and 14 DIN 740 Part 1 Page 3 3.2 Forms Figures 1 to 14 show how the symbols given in table 1 are applied to various coupling forms. A with flexible elements in one or both coupling halves (A); AT with flexible elements in one or both coupling halves (A), and with
18、 one brake drum (T); ATT with flexible elements in one or both coupling halves (A), and with two brake drums (TT); AS with flexible elements in one or both coupling halves (A), and with one brake disc (S); B with flexible elements between the two coupling halves (B); BT with flexible elements betwee
19、n the two coupling halves (B), and with one brake drum (T); BTT with flexible elements between the two coupling halves (B), and with two brake drums (TT); BS with flexible elements between the two coupling halves (B), and with one brake disc (S); AD with flexible elements in one or both coupling hal
20、ves (A), and with a spacer piece (D); BD with flexible elements between the two coupling halves (B), and with a spacer piece (D); AF with flexible elements in one or both coupling halves (A), and with one flange (F); AFF with flexible elements in one or both coupling halves (A), and with two flanges
21、 (FF); BF with flexible elements between the two coupling halves (B), and with one flange (F); BFF with flexible elements between the two coupling halves (B), and with two flanges (FF). Figure 1. Form A LU Figure 2. Form AT Figure 3. Form ATT Figure 4. Form AS Page 4 DIN 740 Part 1 Figure 5. Form B
22、r”1 Figure 7. Form BTT spacer piece I_ II _I Figure 9. Form AD Figure 6. Form BT Figure 8. Form BS Figure 10. Form BD Zl Figure 11. Form AF Figure 12. Form AFF DIN 740 Part 1 Page 5 i Figure 13. Form BF Figure 14. Form BFF 3.3 Examples of standard designation Example 1, form A shaft coupling Term I
23、Nominal torque, TKN, in N m DIN number Form as in subclause 3.2 Shaft coupling DIN 740 - A800 X Maximum torque, TK, Overall torque, TKN ratio 3.5 - 250 X 200 Overall length of coupling, II Maximum diameter of metallic coupling flange, de Example 2, form AS shaft coupling Term I Nominal torque, TKN,
24、in N m DIN number Form as in subclause 3.2 Shaft coupling DIN 740 - AS 400 X 4 - 250 X 400 X 30 I- Maximum torque, TK, Overall torque, SKN ratio Overall length of coupling, I, Diameter of brake disc, d2 Width of brake disc, bl 4 Technical delivery conditions 4.1 Calculation Calculating shall be done
25、 as specified in DIN 740 Part 2. 4.2 Design The design and the choice of material (see subclause 4.3) shall be at the discretion of the coupling manufacturer unless other agreements are made. See DIN 15431 and DIN 15432 for specifications relating to the design of flexible shaft couplings with brake
26、 drum or brake discs. Page 6 DIN 740 Part 1 Material Cast steel Cast steel for quenching and tempering 4.3 Manufacturing process and materials Materials recommended for use are given in tables 2 and 3. Table 2. Examples of metallic materials Material symbol As specified in GS 45, GS 52, GS 60 GS-25
27、CrMo 4 Stahl-Eisen- GS-42 CrMo 4 DIN 1681 Werkstoffb/att*) 51 O Manufactured by P Lamellar graphite cast iron (grey cast iron) 1) forging or by manufacturing from the solid GG-20 GG-30 GG-25 Spheroidal graphite cast iron Structural steel GGG-40 GGG-50 GGG-70 St 50-2, St 60-2, St 70-2 DIN 1693 Part 1
28、 GGG-60 DIN 17 100 DIN 1691 Material Natural rubber Acrylo-nitrile-butadiene rubber Styrene-butadiene rubber Polyurethane elastomers Material symbol NR NBR SBR PUR C 45, C 60, 42 CrMo 4 25 CrMo 4 Steel for quenching and tempering DIN 17 200 1) Depending on the occurrence of jolts or shocks during op
29、eration, the use of coupling components made of lamellar graphite cast iron (grey cast iron) is not permitted in certain plants, e.g. in steel works and in rolling mills. I *) Iron and steel material sheet. DIN 740 Part 1 Page 7 4.6 Dimensional and geometrical tolerances Unless otherwise specified i
30、n the order, finish bores shall be supplied with an H7 tolerance and the width of keyways with a JS 9 tolerance. The general tolerances, accuracy grade m, as specified in DIN 71 68shall apply to the dimensions of mechanically processed work piece surfaces, where no tolerances have been specified. Th
31、e following tolerances shall apply to the dimensions of rough work piece surfaces of coupling elements, where no tolerances have been specified: for cast steel components and components made from cast steel for quenching and tempering, accuracy grade GTB 17 as specified in DIN 1683 Part 1; for lamel
32、lar graphite cast iron components, accuracy grade GTB17 as specified in DIN 1686 Part 1; for spheroidal graphite cast iron components, accuracy grade GTB17 as specified in DIN 1685 Part 1; components made from steel for quenching and tempering (drop forged), tolerances and limit deviations as specif
33、ied in DIN 7526. Table 4. Geometrical tolerances The terms and indications on the drawings correspond to those specified in DIN 7184. Type of tolerance Symbol and toleranced feature Form Run-out Application for coupling components Indications on drawings Hub bore 1) The tolerance may be narrower tha
34、n IT8 if so agreed Tolerance The cylindricity tolerance, ti, shall be equal to I/z of the tolerance set for the hub bore. The tolerance on circular run-out shall be IT81). The specifications given in DIN 15437 (at present at the stage of draft) shall apply to the radial and axial run-out tolerances
35、for flexible shaft couplings with brake drums or brake discs. These same tolerances can be applied analogously to othertypes of coupling. If special requirements are set for the geometrical tolerances for keyways, the relevant orientation and location tolerances shall be specified, e.g. the permissi
36、ble angularity tolerance for two keyways spaced by 1800, or the symmetry tolerance for keyway and bore or for keyway and toothed coupling flange in relation to the central plane of the tooth or of the tooth space. In addition, a symmetry tolerance relating to a given axis may be specified for bores
37、and keyways of a pair of coupling hubs. Unless otherwise specified, the general tolerances, accuracy gracie m-S, as specified in DIN 7168 shall apply. 4.6.1 Rough-bored couplings If flexible shafi couplings are ordered in the rough-bored condition e.g. to simplify stock keeping, the minimum sizes of
38、 diam- eters d4 and d5 shall be specified taking into account an appropriate machining allowance. In the case of 1 : 10 taper finish bores, the minimum size of the cylindrical rough bore shall be equal to d4 - - .The relevant tolerance zone shall be agreed. Unless otherwise agreed, the general toler
39、ances, accuracy grade m, as specified in DIN 7168 shall apply. ( lo) Page 8 DIN 740 Part 1 4.7 Surface finish Agreement shall be reached on the surface finish of machine-finished functional surfaces, of connecting surfaces and of interchangeable connecting elements, in accordance with IS0 1302; e.g.
40、 roughness grade N7 for the machine-finished hub bore and N9 for the keyway. 4.8 Requirements to be met by cast coupling components Cast coupling components shall be free of any externally visible cracks and surface defects which might reduce their service life. 4.9 Requirements to be met by forged
41、coupling components Forged coupling components shall be free of surface cracks and fissures that might impair their use. 4.10 Balancing Standard condition: balanced in one plane, at z1 not exceeding 30m/s, with nmax = 1500min-; quality grade (216; with finish bore, and with keyway if specified by th
42、e purchaser, but without key, or without keyway; in each instance using a polished balancing mandrel as specified in VDI 2060. Subject to agreement: balanced in two planes; at u greater than 30m/s, with nmax = 1500 min-; quality grade Q 6.3 (or finer); with finish bore, and with fitted keyway if spe
43、cified by the purchaser, but without key, or without key- way; in each instance using a polished balancing mandrel as specified in VDI 2060. 4.11 Alignment faces The couplings shall be provided with faces which can be aligned both during boring and assembly. 4.12 Printed information All the technica
44、l details required forthe application and particularly the construction of the drive unit shall be specified by the manufacturer in his technical documentation in accordance with the following specifications, particularly: - materials used for hub components, the brake drum or brake disc and for the
45、 flexible elements; - operating temperature range with respect to coupling and flexible elements; - dimensional and geometrical tolerances; - surface finish; - balancing; - dimensions and associated symbols as in table 1, giving the machining allowance for d4 X Z4 and d5 X 15; - forms as specified i
46、n subclause 3.2; - standard designation as specified in subclause 3.3; - reference to the operating instruction manual; - drive-type fastenings in the event of failure of the flexible elements; - replacement of flexible elements and maintenance by visual check. If interference fits, e.g. shrink fits
47、, are employed, all the data required for the calculation in accordancewith DIN 7190 shall be specified, e.g. - data relating to approval by classification societies; - nominal torque, TKN, in N m; - maximum torque, TK, in N m; - torque under alternating stress, TKw, in N m; - the maximum permissibl
48、e rotational speed, in min-; - values of axial, radial and angular stiffness (Ca, C, and Cw); - permissible values of axial, radial and angular misalignment (AK, A K,., A KJ; - torsional backlash during reversing operations in the idling, wear-free condition; - torsional stiffness, CTdyn. in N mlrad
49、; - damping coefficient y - moment of inertia of the individual coupling components, Il . . . I, in kg m2, and IIl . . . i,; - mass of individual coupling components, in kg, and total mass. DIN 740 Part 1 Page 9 Coupling designation and size 4.1 2.1 Graphic representation, notation and design data 43 27 8 Diameter d4 Diameter ds Total Rough Finish Rough Finish inertial) mass 1) bore bore l4 bore bore Rota- Nominal tionai Moment torque please note that the same item number has been used for the same item for the three different forms illustrated in figures 19 to 21.
