1、DEUTSCHE NORM SeDtember 1996 DIN 3760 Rotary shaft lip seals ICs 21.120.10 Descriptors: Fluid power, lip seals. Supersedes April 1972 edition Radial-Wellendichtringe In keeping with current practice in standards published by the International Organization for Standardization (ISO), a comma has been
2、used throughout as the decimal marker. Foreword This standard has been prepared by the Normenausschu Kautschuktechnik (Rubber Technology Standards Committee). It is based on IS0 6194-1 : 1982. Amendments The following amendments have been made to the April 1972 edition. a) For shaft diameters 32, 35
3、, 38 and 40 mm, a nominal width of 8 mm has been introduced to account for new designs. b) Information to be provided by both the manufacturer and the purchaser has been included. c) The standard has been editorially revised. Previo us edit ions DIN 3760: 1962-02, 1972-04. Dimensions in mm 1 Scope a
4、nd field of application This standard specifies dimensions and requirements for materials, marking, use and installation of rotary shaft lip seals used for retaining fluid or grease in unpressurized equipment, or equipment with a low differential pressure, that has rotating shafts. Where seals are i
5、ntended for use in applications other than those specified in this standard, the seal manufacturer should be consulted. 2 Normative references This standard incorporates, by dated or undated reference, provisions from other publications. These normative references are cited at the appropriate places
6、 in the text and the titles of the publications are listed below. For dated references, subsequent amendments to or revisions of any of these publications apply to this standard only when incorporated in it by amendment or revision. For undated references, the latest edition of the publication refer
7、red to applies. DIN 51 524-1 Type HL hydraulic oils - Minimum requirements DIN 51 524-2 Type HLP hydraulic oils - Minimum requirements DIN 51524-3 Type HVLP hydraulic oils - Minimum requirements IS0 1629 : 1995 Rubbers and latices - Nomenclature IS0 4287-1 : 1984 Surface roughness - Terminology - Pa
8、rt 1: Surface and its parameters IS0 61 94-1 : 1982 Rotary shaft lip type seals - Part 1 : Nominal dimensions and tolerances Continued on pages 2 to 13 Translation by DI N-Sprachendienst. In case of doubt, the German-language original should be consulted as the authoritative text. No pari of this tr
9、anslation may be reproduced without the prior permission of Ref. No. DIN 3760 : 1996-0 V Deutsches Institut fr Nonung e. V., Berlin. Luth Verlag GmbH, D-10772 Berlin, has the exclusive right of sale for German Standards (DIN-Normen). - English price group O9 Sales No . .o109 08.98 Page 2 DIN 3760 :
10、1996-09 VDMA-finheitsblatt (VDMA Code of practice) 2431 7 Fluid power systems - Hydraulics - Fire-resistant hy- draulic fluids, guidelines ASTM D 141 8 : 1992*) Rubber and rubber latices - Nomenclature 3 Dimensions and designations Rotary shaft lip seals are not expected to conform to the designs il
11、lustrated here; compliance is only required in the case of the dimensions specified. Type A Type AS i1 a) Elastomeric component b) Metal insert c) Garter spring d) Sealing lip a) Minor lip Dimensions and details as for type A. Figure 1: Rotary shaft lip seal without minor lip Figure 2: Rotary shaft
12、lip seal with minor lip Designation of a type A rotary shaft lip seal intended for a shaft diameter,d, of 25 mm, with an outside diameter, d, of 40 mm and a width, b, of 7 mm, with an elastomeric component of acrylonitrile/butadiene rubber (NBR): EXAMPLE 1: Lip seal DIN 3760 - A25 x 40 x 7 - NBR If
13、seals are to be marked with a symbol denoting the material of the elastomeric component used (cf. subclause 5.2), a G shall be included in the designation. EXAMPLE 2: Lip seal DIN 3760 - A25 x 40 x 7 - NBR - G If it is required that metal inserts and springs be provided with an improved corrosion pr
14、otection, a K shall be included in the designation. EXAMPLE 3: Lip seal DIN 3760 - A25 x 40 x 7 - FKM - K or Lip seal DIN 3760 - A25 x 40 x 7 - FKM - GK *) Obtainable from Beuth Verlag GmbH (Auslandsnormen-Sen/ice), D-10772 Berlin. Page 3 DIN 3760 : 1996-09 Table 1 : Nominal dimensions c2) min. dl i
15、 02 Shaft diameter, d21) b 12 120 125 120 95 0,4 1 O0 125 12 130 Shaft diameter, both the elastomer and the lubricant shall be chemically resistant to the fluids present in the shaft assembly. Limits for the operating conditions (e.g. fluid pressure, shaft speed, chemical and thermal resistance of t
16、he elastomere used) are given in subclauses 6.1 and 6.2. If all of these limits will be reached simultaneously, or if individual limits will be exceeded, the seal manufacturer should be consulted (cf. annexes A and B). Shaft Maximum Resulting maxi- rotational speed, mum peripheral in min- speed, in
17、m/s, up to 1000 2,a up to 2000 3,15 up to 3000 5,6 6.1 Maximum permissible shaft speed 6.1.1 Unpressurized operation The maximum permissible rotational speed of the shaft during unpressurized operation is given in figure 3 as a function of the elastomeric component material. The heat transfer system
18、 shall be capable of maintaining the permissible temperature of the test fluid and shall be vented to atmosphere. 6.1.2 Pressurized operation Lip seals shall be capable of retaining fluid or grease at low differential pressures, as well as air (provided there is sufficient lubrication). Table 4 give
19、s the maximum differential pressure as a function of the rotational and peripheral speeds. 7 Seal installation 7.1 General In addition to the manufacturers instructions, the following guidelines shall be observed when installing seals. The sealing lip shall face the fluid to be sealed and shall be u
20、nobstructed. The seal shall be pressed home and completely square by means of suitable installation tools, taking care to prevent misalignment and to ensure that the seal does not carry any load in service. To prevent damage to the sealing lip during installation, it is recommended that a) the shaft
21、 be rounded (with a corner radius of r,) or chamfered (if the shaft is fitted in directionz or the seal fitted in direction y, as in figure 4) or b) the shaft be chamfered (if the shaft is fitted in direction y or the seal fitted in direction z, as in figure 4). Page 6 DIN 3760 : 1996-09 - Rotationa
22、l speed U a, a, Q cn Figure 3: Maximum permissible rotational speed for unpressurized operation z Direction of installation c_ a) Fluid side b) Edges rounded Figure 4: Installation Page 7 DIN 3760 : 1996-09 100 1 90 90 - - 80 80 100 90 90 90 70 70 i$+ - 30 150 Table 5: Chemical stability of base ela
23、stomers 1 150 140 150 130 e e 150 O Co i; + Shaft diameter, d, I (4 - d3) ) I di (4 - d3) 1 Fluids based on petroleum products I I I L dl 10 13 Over 50 up to 70 Over 10 up to 20 290 over 70 up to 95 over 20 up to 30 23 over 95 up to 130 over 30 up to 40 3,O over 130 up to 240 over 40 up to 50 3,5 ov
24、er 240 up to 500 Fluids present 40 4,5 5.5 7.0 11 ,o Co a, Co l3 a, L a - Non-flammable pressure fluids as in VDMA 2431 7 S O 3 O 3 a, .- + - S .- O Co - Co L - E, 2 8 O Q Co 3 S L O a, a, + 3 k - .- ? .- 3,O 3,5 I Maximum continuous operating temperature of fluid, in “C 7.2 Shaft Shafts shall meet
25、the requirements specified in subclauses 7.2.1 to 7.2.3 and table 6. I I I) If there is a shaft lead-in chamfer, its radius shall be no less than this difference. 7.2.1 Surface roughness of shafts In order to ensure a tight fit between seal and shaft, the seal land (cf. subclause 7.2.3) shall have a
26、 surface roughness, Ra*), of 0,2 to 0,8 pm or R,*), of 1 to 5 pm, with R,*) = 6,3 pm. 7.2.2 Surface hardness The service life of seals depends on the surface hardness at the seal land. It should be at least 45 HRC. Where ingress of contaminated fluid is to be expected, or where the peripheral speed
27、exceeds 4 m/s, the hardness should be at least 55 HRC. Where shafts are not fully hardened, the effective depth of hardening should be at least 0,3 mm. After nitriding, shafts shall be provided with a smooth surface finish. 7.2.3 Seal land The valuesfor surface roughness and hardness specified in su
28、bclauses 7.2.1 and 7.2.2 shall be maintained over the entire seal land, whose dimensions shall be as specified in table 7. It is essential that the shaft is not subject to eccentric running, to prevent leakage. *) In accordance with IS0 4287-1: Ra-arithmetical mean deviation of the profile; R, - ten
29、 point height of irreglarities; Rmax - maximum two point height of the profile. Page 8 DIN 3760 : 1996-09 b - 7 8 -II- with sealing lip only el e2 min. 3.5 61 3.5 68 495 83 5 10 6 12 9 18.5 a) No eccentric running b) Seal land with sealing lip and minor lip e3 e4 min. 1.5 7,6 1 r5 83 2 10,5 2 12 3 1
30、5 3 19.5 10 12 15 20 u bl a) No eccentric running b) Seal land Figure 5: Seal land (notation) 7.3 Housing bore The housing bore shall be subject to a class H8 tolerance and shall have a maximum surface roughness Ra*), of 1,6 to 6,3 pm or R,*), of 10 to 20 pm, with R,*) = 25 pm. The bore shall have t
31、he dimensions specified in table 8 and a lead-in chamfer of about 1 O to 20“. 1 O“ to 20“ Figure 6: Housing bore (notation) *) In accordance with IS0 4287-1 : Ra - arithmetical mean deviation of the profile; R, - ten point height of irreglarities; Rmax - maximum two point height of the profile. Page
32、 9 DIN 3760 : 1996-09 Nominal tl bore (0,85. b) depth, b min. 7 5.95 8 68 10 83 12 10,3 15 12,75 20 17 t2 r2 (b + 0,3) min. max. 7,3 8,3 OS 10,3 12,3 15.3 0,7 20,3 7.4 Housing bore coaxiality The housing bore shall be coaxial with the shaft axis within the tolerances specified in figure 7. It should
33、 be noted that tolerances are to be smaller where sealing lips are thinner. Wider tolerances may apply if other types of elastomer or more flexible seal lip designs have been used to modify the performance of the seal. i 0,8 E E .- c 0,6 a 2 0.4 g 0.2 o C a, O x (u X (u O - + .- O0 280 to 500 Shaft
34、diameter, d, in mm + Figure 7: Coaxiality tolerance 7.5 Shaft run-out The tolerances on shaft run-out shall be as shown in figure 8. It should be noted that in the case of higher shaft speeds, the sealing edge may not be able to follow any shaft movement due to its own inertia. If the shaft run- out
35、 results in the distance between sealing edge and shaft becoming larger than required for maintaining hydrodynamic lubrication, oil may leak from the seal. It is therefore advisable to position the seal as close as possible to the bearing to minimize the clearance between bearing elements. 5 4 35 3
36、25 2 15 1 o5 O O 1000 2000 3000 4000 5000 7000 Rotational speed of shaft, in min-l- Figure 8: Run-out tolerance Page 1 O DIN 3760 : 1996-09 Annex A Information provided by the purchaser To allow the manufacturer to supply a seal suitable for the application in question, it is recommended that the pu
37、rchaser provide the information given in the specimen form shown below. (The note in the margin on page 1 prohibiting reproduction of any part of this standard does not apply to the following specimen form.) Table A: Information provided by the purchaser Purchaser: Reference: Application: Assembly d
38、rawing: 1 Shaft information a) Diameter (d,) mm max. mm min. b) Material c) Surface roughness Ra Iim, RZ wn Rmax I.lm d) Type of finish e) Hardness f) Chamfer information g) Rotation 1) Direction of rotation (viewed in direction of arrow as shown in drawing) - Clockwise - Anti-clockwise - Birotation
39、al 2) Rotational speed min- 3) Rotation cycle (Time on Time off ) h) Other shaft motion (if applicable) 1) Reciprocation - i) Length of stroke mm -i) Cycles per minute - iii) Reciprocation cycle (Time on Time off ) 2) Oscillation - i) Magnitude of oscillation (degrees) -i) Cycles per minute - iii)Os
40、cillation cycle (Time on Time off ) Bore depth, t, j) Additional information (e.g. regarding splines, holes, keyways, shaft lead, etc.) (continued) Page 11 DIN 3760 : 1996-09 Table A (concluded) 2 Housing information a) Bore diameter (D) mm max. mm min. b) Bore depth mm max. mm min. c) Material d) S
41、urface roughness Ra CLm, Rz ii.m, R, Pm e) Chamfer information f) Housing rotation (if applicable) 1) Direction of rotation (viewed in direction of arrow as shown in drawing overleaf) -Clockwise - Anti-clockwise - Birotational 2) Rotational speed min- 3 Contained fluid information a) Type of fluid G
42、rades b) Fluid temperature Normal: “C “C Max. “C Min. c) Temperature cycle d) Fluid level e) Fluid pressure bar kPa f) Pressure cycle 4 Alignment a) Housing bore eccentricity b) Shaft run-out 5 External conditions a) External pressure bar kPa b) Materials to be excluded (.e. dust, mud, water, etc.)
43、Annex B Information provided by the manufacturer It is also recommended that the manufacturer provide the information given in the following specimen form. This information will ensure that the seal is compatible with the equipment design and the application in question, and will facilitate inspecti
44、on and quality control as well. (The note in the margin on page 1 prohibiting reproduction of any part of this standard does not apply to the following specimen form.) Page 12 DIN 3760 : 1996-09 Table B: Information provided by the manufacturer Manufacturer: Part No. Charge No. Date Seal specificati
45、ons: Type: Outside diameter, d,: mm max. mm min. Seal width, b: mm max. mm min. Sealing lip description (if applicable): Plain Unirotational Hydrodynamic Birotational Sealing lip material specifications: Material type: Specification: Case specifications: Case material: Inner case material: Case thic
46、kness: Inner case thickness: Spring material: Optional information: Assessment of results: I Sample drawing: di Page 13 DIN 3760 : 1996-09 Other relevant standards IS0 61 94-2 : 1991 Rotary shaft lip seals - Part 2: Vocabulary IS0 61 94-3 : 1988 Rotary shaft lip seals - Part 3: Storage, handling and installation IS0 61 94-4 : 1988 Rotary shaft lip seals - Part 4: Performance test procedures IS0 61 94-5 : 1990 Rotary shaft lip seals - Part 5: Identification of visual imperfections
