1、ASD STANDARD NORME ASD ASD NORM prEN 2755 Edition P 3 January 2008 PUBLISHED BY THE AEROSPACE AND DEFENCE INDUSTRIES ASSOCIATION OF EUROPE - STANDARDIZATIONAvenue de Tervuren, 270 - B-1150 Brussels - Tel. + 32 2 775 8126 - Fax. + 32 2 763 3565 - www.asd-stan.orgICS: Supersedes edition P 2 September
2、1995 Descriptors: ENGLISH VERSION Aerospace series Bearings, spherical plain in corrosion resisting steel with self-lubricating liner Elevated load at ambient temperature Technical specification Srie arospatiale Rotules, en acier rsistant la corrosion garniture autolubrifiante Srie charge leve tempr
3、ature ambiante Spcification technique Luft- und Raumfahrt Gelenklager, aus korrosionsbestndigem Stahl mit selbstschmierender Beschichtung Reihe hohe Belastungen bei Raumtemperatur Technische Lieferbedingungen This “Aerospace Series“ Prestandard has been drawn up under the responsibility of ASD-STAN
4、(The AeroSpace and Defence Industries Association of Europe - Standardization). It is published for the needs of the European Aerospace Industry. It has been technically approved by the experts of the concerned Domain following member comments. Subsequent to the publication of this Prestandard, the
5、technical content shall not be changed to an extent that interchangeability is affected, physically or functionally, without re-identification of the standard. After examination and review by users and formal agreement of ASD-STAN, it will be submitted as a draft European Standard (prEN) to CEN (Eur
6、opean Committee for Standardization) for formal vote and transformation to full European Standard (EN). The CEN national members have then to implement the EN at national level by giving the EN the status of a national standard and by withdrawing any national standards conflicting with the EN. Editi
7、on approved for publication 31 January 2008 Comments should be sent within six months after the date of publication to ASD-STAN Mechanical Domain Copyright 2008 by ASD-STAN prEN 2755:20082 Contents Page Foreword2 1 Scope 3 2 Normative references 3 3 Terms and definitions .4 4 Requirements characteri
8、stics, inspection and test method .5 5 Quality assurance16 5.1 Production qualification16 5.2 Acceptance conditions .17 6 Packaging.17 7 Certificate of compliance17 Annex A (normative) Verification of permissible and ultimate static loads .22 A.1 Permissible radial static load (Cs)22 A.2 Ultimate ra
9、dial static load .22 A.3 Permissible axial static load (Ca)23 A.4 Ultimate axial static load.23 Annex B (normative) Verification of dynamic radial load (C25).26 B.1 Principle26 B.2 Method 26 Annex C (normative) Fluids Essential characteristics.28 C.1 Fuel for turbine aero engine .28 C.2 Fluids for d
10、e-icing circuit28 C.3 Hydraulic fluids28 Annex D (normative) Measurement of the peel strength of the liner.29 D.1 Principle29 D.2 Method 29 Annex E (normative) Simplified qualification procedure30 E.1 Rules for application .30 E.2 Choice of references .30 E.3 Rules for qualification .31 E.4 Plain be
11、aring distribution .32 Foreword This standard was reviewed by the Domain Technical Coordinator of ASD-STANs Mechanical Domain. After inquiries and votes carried out in accordance with the rules of ASD-STAN defined in ASD-STANs General Process Manual, this standard has received approval for Publicati
12、on. prEN 2755:2008 3 1 Scope This standard specifies the required characteristics, inspection and test methods, qualification and acceptance conditions for spherical plain bearings in corrosion resisting steel, with self-lubricating liner, for elevated loads at ambient temperature intended for use i
13、n fixed or moving parts of the aircraft structure and control mechanisms. This standard applies whenever referenced. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated ref
14、erences, the latest edition of the referenced document (including any amendments) applies. ISO 11078, Aerospace Aircraft de-icing/anti-icing non-Newtonian fluids, ISO type II. EN 2064, Aerospace series Bearings spherical plain in corrosion resisting steel with self lubricating liners Technical speci
15、fication. EN 2584, Aerospace series Bearings, spherical plain in corrosion resisting steel with self-lubricating liner Narrow series Elevated load at ambient temperature Dimensions and loads. EN 2585, Aerospace series Bearings, spherical plain in corrosion resisting steel with self-lubricating liner
16、 Wide series Elevated load at ambient temperature Dimensions and loads. EN 3048, Aerospace series Bearings, spherical plain in corrosion resisting steel with self-lubricating liner Light series Elevated load at ambient temperature Dimensions and loads. EN 4037, Aerospace series Bearings, spherical p
17、lain in corrosion resisting steel with self-lubricating liner reduced starting torque Light series Dimensions and loads. 1)EN 4038, Aerospace series Bearings, spherical plain in corrosion resisting steel with self-lubricating liner reduced starting torque Normal narrow series Dimensions and loads. 1
18、)EN 4039, Aerospace series Bearings, spherical plain in corrosion resisting steel with self-lubricating liner reduced starting torque Normal wide series Dimensions and loads. 1)EN 4040, Aerospace series Bearings, spherical plain in corrosion resisting steel with self-lubricating liner with wide inne
19、r ring Elevated loads at ambient temperature Dimensions and loads. EN 4613, Aerospace series Bearings, spherical plain, in corrosion resisting steel, with self-lubricating liner Narrow series Dimensions and loads Inch series. 1)EN 4614, Aerospace series Bearings, spherical plain, in corrosion resist
20、ing steel, with self-lubricating liner Wide series Dimensions and loads Inch series. 1)EN 6096, Aerospace series Bearings, spherical plain, in corrosion resisting steel, with self-lubricating liner and extra wide inner ring Dimensions and loads Inch series.2) 1) Published as ASD Prestandard at the d
21、ate of publication of this standard. 2) In preparation at the date of publication of this standard. prEN 2755:20084 EN 9100, Aerospace series Quality management systems Requirements (based on ISO 9001:2000) and Quality systems Model for quality assurance in design, development, production, installat
22、ion and servicing (based on ISO 9001:1994). EN 9133, Aerospace series Quality management systems Qualification procedure for aerospace standard parts. EN 10204, Metallic products Types of inspection documents. TR 4475, Aerospace series Bearings and mechanical transmissions for airframe applications
23、Vocabulary. 3)3 Terms and definitions For the purposes of this document, the terms and definitions given in TR 4475 and the following apply. 3.1 spherical plain bearings with self-lubricating liner a spherical plain bearing consisting of two concentric rings between which is interposed a self-lubric
24、ating liner which is bonded or moulded onto the spherical inner surface or the spherical outer surface 3.2 Surface discontinuities 3.2.1 score, scratch open surface defect 3.2.2 lap surface defect where particles of metal or sharp edges are folded over and then rolled or forged into the surface 3.2.
25、3 seam unwelded fold which appears as an open defect in the material 3.3 starting torque at without load torque required to start the rotation of the inner with the outer ring held stationary 3.4 Permissible static loads 3.4.1 radial, Csa static load corresponding to a permissible unit pressure mult
26、iplied by the effective projected area in the radial direction, the inner ring being able to take any position within the limits of the tilting angle indicated in the product standard 3.4.2 axial, Caa static load corresponding to a permissible unit pressure multiplied by the effective projected area
27、 in the axial direction 3) Published as ASD Technical Report at the date of publication of this standard. prEN 2755:2008 5 3.5 dynamic radial,C25a load which may be withstood by a bearing submitted to an oscillatory movement for a defined number and frequency of oscillation cycles without the dimens
28、ional or other characteristics deviating from the values permitted by the technical specification of the product One oscillating cycle includes an angular displacement of the inner ring in relation to the outer ring from 0 to 25 then from 25 to 25 and finally from 25 to 0. 3.6 adhesion of the liner
29、area where the adhesive bond is broken or non existant leaving a smooth and clean interface on the metallic surface 3.7 production batch batch of products composed of elements which may come from more than one element batch but which are assembled in the same production series 4 Requirements charact
30、eristics, inspection and test method See Table 1. prEN 2755:20086 Table 1 Clause Characteristic Requirements Inspection and test method Q aA bX X 4.1 Material In accordance with the product standard or design documentation Chemical analysis or certificate of compliance according to EN 10204, issued
31、by semi-finished product manufacturer X X Suitable measuring instruments X X 4.2 Dimensions, tolerances In accordance with the product standard or design documentation Measurement of bore and outer diameter: Rings with a width of 10 mm: in the centre plane; Rings with a width of 10 mm: in two planes
32、 parallel to the outer faces and at a distance of these faces of twice the maximum value of the ring chamfer. The minimum and maximum diameters shall be determined in each measuring plane. Measurement of ring width: The width of each ring (distance between the two faces) shall be verified at a minim
33、um of four points. 4.3 Masses In accordance with the product standard or design documentation Suitable methods X 4.4 Marking In accordance with the product standard or design documentation It shall be legible and shall not adversely affect the material or the functioning of the bearing. Visual exami
34、nation X X 4.5 Surface appearance The bearings shall be free of surface discontinuities liable to have an adverse effect on their characteristics and endurance. The liner shall not contain contaminant products and shall not show broken or voided areas. Lubrication shall not be permitted. 4.5.1 Assem
35、bled bearings Visual inspection using suitable methods X X 4.5.2 Unassembled rings Magnetic or dye penetrant inspection X X continued prEN 2755:20087 Table 1 (continued) Clause Characteristic Requirements Inspection and test method Q aA b4.6 Hardness In accordance with the product standard or design
36、 documentation Suitable processes and measuring instruments X X 4.7 Surface roughness In accordance with the product standard or design documentation Suitable processes and measuring instruments X X Visual inspection X X 4.8 Surface treatment In accordance with the product standard or design documen
37、tation As per surface treatment standard 4.9 Behaviour in rotation and tilt Bearings shall be able to move freely within the angular limits specified in the product standards or design documentation. Manual inspection X X 4.10 Starting torque without load Suitable processes and measuring instruments
38、: X X 4.10.1 At ambient temperature In accordance with the product standard or design documentation measurement of the starting torque shall be preceded by some rotations and a few turning movements by hand; measure the torque, apply gradually to the inner ring, in both directions, with the outer ri
39、ng held stationary. Read off the maximum value required to start up the inner ring. Subject the bearing, during 4 h at the minimum temperature 5 C. X 4.10.2 At low temperature Starting torque twice those listed in the product standard or design documentation Immediately after, measure the torque fol
40、lowing 4.10.1. 4.10.3 After limit temperatures In accordance with Tables 2 and 3 Subject the bearing, during 1 h at the minimum temperature 5 C, then 1 h at the maximum temperature 2 C. X Repeat successively 10 this test. 4 h after these tests, measure the torque, at ambient temperature, following 4
41、.10.1. continued prEN 2755:20088 Table 1 (continued) Clause Characteristic Requirements Inspection and test method Q aA bClad the bearing in plastic material identical to that used for metallurgical mounts. X Section the bearing on a diameter and normal to the race side face. Grind and polish the ex
42、posed surface. 4.11 Conformity of spherical surface For fabric type liners no difference between measurements obtained on spherical surfaces shall exceed 0,08 mm. Measure distance t, checked at a minimum of five points uniformly spaced around the spherical diameter with the aid of, for example, an o
43、ptical dial indicator (see Figure 1). Clad the bearing in plastic material identical to that used for metallurgical mounts. X Section the bearing on a diameter and normal to the race side face. Grind and polish the exposed surface. For moulded liners: the maximum liner thickness shall occur between
44、C/10 position; the minimum liner thickness shall be 0,20 mm. Measure distance t, checked at a minimum of five points uniformly spaced around the spherical diameter with the aid of, for example, an optical dial indicator (see Figure 1). The points shall include the midpoint and the C/10 positions. 4.
45、12 In accordance with the product standard or design documentation. See Annex A. X No maximum total deflection greater than those listed in Tables 4 and 5 under permissible static loads (Cs). Permissible static loads: radial: Cs axial: CaAfter removing the loads, no permanent deformations greater th
46、an those listed in Tables 4 and 5. 4.13 Ultimate static loads: radial axial After removing the loads, there shall be no cracks, no push out of the inner ring or deterioration of the bearing. See Annex A. continued prEN 2755:20089 Table 1 (continued) Clause Characteristic Requirements Inspection and
47、test method Q aA bIn accordance with the product standard or design documentation. See Annex B. X After the removal of the loads : no metal-to-metal contact between inner and outer ring; the liner wear shall not exceed the values listed in Table 6; the peel strength and the bond integrity shall conf
48、orm with 4.16 and 4.17. 4.14 Dynamic radial loads C25: at ambient temperature at low temperature at elevated temperature At the end of the test, the starting torque under radial load shall be measured and shall conform with values listed in Tables 7 and 8. Suitable processes and measuring instrument
49、s Check one bearing per fluid : X put the inner ring perpendicularly to the outer ring; the bearing shall be immersed for 24 h in the fluids stated in Annex C at the following temperatures: (45 3) C for those defined in C.1 and C.2; (70 3) C for those defined in C.3; ambient temperature for those defined in C.4. 4.15 Liner compatibility with the fluids At the end of this test, see 4
