SIST EN 2755:2009

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.KQLþQDVSHFLILNDFLMDLuft- und Raumfahrt - Gelenklager, aus korrosionsbeständigem Stahl mit selbstschmierender Beschichtung - Reihe hohe Belastungen bei Raumtemperatur - Technische LieferbedingungenSérie aérospatiale - Rotules, en acier résistant à la corrosion à garniture autolubrifiante - Série à charge élevée à température ambiante - Spécification techniqueAerospace series - Bearings, spherical plain in corrosion resisting steel with self-lubricating liner - Elevated load at ambient temperature - Technical specification49.035Sestavni deli za letalsko in vesoljsko gradnjoComponents for aerospace constructionICS:Ta slovenski standard je istoveten z:EN 2755:2009SIST EN 2755:2009en01-november-2009SIST EN 2755:2009SLOVENSKI
STANDARD



SIST EN 2755:2009



EUROPEAN STANDARDNORME EUROPÉENNEEUROPÄISCHE NORMEN 2755July 2009ICS 49.035 English VersionAerospace series - Bearings, spherical plain in corrosionresisting steel with self-lubricating liner - Elevated load atambient temperature - Technical specificationSérie aérospatiale - Rotules en acier résistant à lacorrosion à garniture autolubrifiante - Série à charge élevéeà température ambiante - Spécification techniqueLuft- und Raumfahrt - Gelenklager, auskorrosionsbeständigem Stahl mit selbstschmierenderBeschichtung - Reihe hohe Belastungen beiRaumtemperatur - Technische LieferbedingungenThis European Standard was approved by CEN on 16 April 2009.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the CEN Management Centre or to any CEN member.This European Standard exists in three official versions (English, French, German). A version in any other language made by translationunder the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as theofficial versions.CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMITÉ EUROPÉEN DE NORMALISATIONEUROPÄISCHES KOMITEE FÜR NORMUNGManagement Centre:
Avenue Marnix 17,
B-1000 Brussels© 2009 CENAll rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 2755:2009: ESIST EN 2755:2009



EN 2755:2009 (E) 2 Contents Page Foreword . 4 1 Scope . 5 2 Normative references . 5 3 Terms and definitions . 6 4 Requirements characteristics, inspection and test method . 7 5 Quality assurance .18 5.1 Production qualification .18 5.2 Acceptance conditions .19 5.2.1 Inspection and tests to be carried out by the manufacturer .19 5.2.2 Purchaser's (user's) quality control .19 6 Packaging .19 7 Certificate of compliance .19 Annex A (normative)
Verification of permissible and ultimate static loads.24 A.1 Permissible radial static load (Cs) .24 A.1.1 Principle .24 A.1.2 Method .24 A.2 Ultimate radial static load .24 A.2.1 Principle .24 A.2.2 Method .24 A.3 Permissible axial static load (Ca) .25 A.3.1 Principle .25 A.3.2 Method .25 A.4 Ultimate axial static load .25 A.4.1 General .25 A.4.2 Principle .25 A.4.3 Method .25 Annex B (normative)
Verification of dynamic radial load (C25) .28 B.1 Principle .28 B.2 Method .28 B.2.1 Testing at ambient temperature .28 B.2.2 Testing at low temperature .28 B.2.3 Testing at elevated temperature.28 B.2.4 Test at ambient temperature after immersion .29 Annex C (normative)
Fluids – Essential characteristics .30 C.1 Fuel for turbine aero engine .30 C.2 Fluids for de-icing circuit .30 C.3 Hydraulic fluids .30 C.3.1 Mineral fluid for hydraulic transmission .30 C.3.2 Phosphate of ester hydraulic fluid .30 C.4 De-icing and anti-icing fluids .30 Annex D (normative)
Measurement of the peel strength of the liner .31 D.1 Principle .31 D.2 Method .31 Annex E (normative)
Simplified qualification procedure .33 E.1 Rules for application .33 E.1.1 General .33 SIST EN 2755:2009



EN 2755:2009 (E) 3 E.2 Choice of references . 33 E.3 Rules for qualification . 34 E.3.1 If the manufacturer has not previously obtained qualification according to this standard the first metric or inch series plain bearing to be tested shall be subject to full testing (number of samples: 13). . 34 E.3.2 To obtain the qualification of the other dimensions, the selected plain bearings should pass according to this standard: . 34 E.3.3 Qualification of one plain bearing size of an EN product standard qualifies the plain bearing immediately before and the one immediately after the plain bearing in question, within the range of plain bearings indicated in the product standard. . 35 E.3.4 To qualify on group, at least one dimension of each torque type of plain bearing should have been qualified. . 35 E.3.5 As inch and metric series plain bearings are very similar in group 1 and 2, qualification of one metric size bearing of an EN product standard qualifies the inch size bearing in accordance with Table E.2. . 35 E.4 Plain bearing distribution . 35
SIST EN 2755:2009



EN 2755:2009 (E) 4 Foreword This document (EN 2755:2009) has been prepared by the Aerospace and Defence Industries Association of Europe - Standardization (ASD-STAN). After enquiries and votes carried out in accordance with the rules of this Association, this Standard has received the approval of the National Associations and the Official Services of the member countries of ASD, prior to its presentation to CEN. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by January 2010, and conflicting national standards shall be withdrawn at the latest by January 2010. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. SIST EN 2755:2009



EN 2755:2009 (E) 5 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 in 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 references, the latest edition of the referenced document (including any amendments) applies. EN 2064, Aerospace series — Bearings spherical plain in corrosion resisting steel with self-lubricating liner — Technical specification EN 2584, Aerospace series — Bearings, spherical plain in corrosion resisting steel with self-lubricating liner — Narrow series — Elevated loads at ambient temperature — Dimensions and loads EN 2585, Aerospace series — Bearings, spherical plain in corrosion resisting steel with self-lubricating liner — 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 plain 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 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 inner ring — Elevated loads at ambient temperature — Dimensions and loads EN 4613, Aerospace series — Spherical plain bearings in corrosion resisting steel with self-lubricating liner, narrow series — Dimensions and loads — Inch series 1 EN 4614, Aerospace series — Spherical plain bearings in corrosion resisting 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 EN 9100, Aerospace series — Quality management systems — Requirements (based on ISO 9001:2000) and Quality systems — Model for quality assurance in design, development, production, installation and servicing (based on ISO 9001:1994)
1 In preparation at the date of publication of this standard. SIST EN 2755:2009



EN 2755:2009 (E) 6 EN 9133, Aerospace series — Quality management systems — Qualification procedure for aerospace standard parts EN 10204, Metallic products — Types of inspection documents ISO 11078, Aircraft — De-icing/anti-icing fluids, ISO type II, III and IV TR 4475, Aerospace series — Bearings and mechanical transmissions for airframe applications — Vocabulary 2 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 spherical plain bearing consisting of two concentric rings between which is interposed a self-lubricating 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 3.2.3 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 Cs static load corresponding to a permissible unit pressure multiplied 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 Ca static load corresponding to a permissible unit pressure multiplied by the effective projected area in the axial direction
2 Published as ASD Technical Report at the date of publication of this standard. SIST EN 2755:2009



EN 2755:2009 (E) 7 3.5 dynamic radial C25 load which may be withstood by a bearing submitted to an oscillatory movement for a defined number and frequency of oscillation cycles without the dimensional or other characteristics deviating from the values permitted by the technical specification of the product NOTE 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 area where the adhesive bond is broken, or non existent, 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 characteristics, inspection and test method
See Table 1. SIST EN 2755:2009



EN 2755:2009 (E) 8 Table 1 Clause Characteristic Requirements Inspection and test method Q a A b 4.1
Material In accordance with the product standard or design documentation. Chemical analysis or certificate of compliance according to EN 10204, issued by semi-finished product manufacturer. X X X X 4.2
Dimensions, tolerances In accordance with the product standard or design documentation. Suitable measuring instruments. X X 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 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 minimum 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 examination. 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
Assembled bearings
Visual inspection using suitable methods. X X 4.5.2
Unassembled rings
Magnetic or dye penetrant inspection. X X continued SIST EN 2755:2009



EN 2755:2009 (E) 9 Table 1 (continued) Clause Characteristic Requirements Inspection and test method Q a A b 4.6
Hardness In accordance with the product standard or design 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 4.8
Surface treatment In accordance with the product standard or design documentation. Visual inspection. X X 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
4.10.1
At ambient temperature In accordance with the product standard or design documentation. Suitable processes and measuring instruments: X X  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 ring held stationary. Read off the maximum value required to start up the inner ring.
4.10.2
At low temperature Starting torque ≤ twice those listed in the product standard or design documentation. Subject the bearing, during 4 h at the minimum temperature ± 5 °C. X
Immediately after, measure the torque following 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 4.10.1.
continued SIST EN 2755:2009



EN 2755:2009 (E) 10 Table 1 (continued) Clause Characteristic Requirements Inspection and test method Q a A b 4.11
Conformity of spherical surface For fabric type liners no difference between measurements obtained on spherical surfaces shall exceed 0,08 mm. 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.
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).
For moulded liners:  the maximum liner thickness shall occur between C/10 position;  the minimum liner thickness shall be 0,20 mm. 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.
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.
4.12
Permissible static loads:  radial: Cs  axial: Ca 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).
After removing the loads, no permanent deformations greater than 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 SIST EN 2755:2009



EN 2755:2009 (E) 11 Table 1 (continued) Clause Characteristic Requirements Inspection and test method Q a A b 4.14
Dynamic radial loads C25:  at ambient temperature  at low temperature  at elevated temperature In 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 conform with 4.16 and 4.17.
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 instruments.
4.15
Liner compatibility with the fluids At the end of this test, see 4.14.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.
Within ½ h after this test, proceed to the test defined in B.2.4.
4.16
Peel strength of the liner These requirements and this test apply only in the case where the manufacturer has established whether the liner is peelable or non peelable. See Annex D. For acceptance, this test shall be carried out immediately after assembling and curing. X X
It shall present a mean peeling resistance > 0,35 N for each millimetres of the outer ring reduced by 2 mm to eliminate the effects of edges and chamfers.
Mean peeling resistance is determined using at least 75 % of the values on the recording curve.
continued SIST EN 2755:2009



EN 2755:2009 (E) 12 Table 1 (concluded) Clause Characteristic Requirements Inspection and test method Q a
A b
4.17
Bond integrity of the liner For peelable liner, the liner: After the peel strength test, evaluate the location and size of any voids. X X
 shall not contain any contamination substances;
 shall adhere tightly to the outer ring over at least 90 % of the contact area. No void shall be allowed which cannot be described within a circle of diameter equal to:
 25 % of outer ring width;
 6 mm
whichever is smaller.
For non-peelable liners, a sectioned bearing shall be examined for bond integrity. Destructively examine the liner by chipping, scraping, abrasion, or other appropriate means to determine the bond integrity. X X
The liner:
 shall adhere tightly to the outer ring over at least 90 % of the contact area. No void shall be allowed which cannot be circumscribed within a circle of diameter equal to:
 25 % of outer ring width;
 6 mm
whichever is smaller.
a Q: Qualification test. b A: Acceptance test.
SIST EN 2755:2009



EN 2755:2009 (E) 13 Table 2 — Starting torques without load for bearings, metric series
Diameter Metric series Starting torque without load Code Nom. EN 2584 EN 4038 EN 2585 EN 4039 EN 3048 EN 4037 EN 4040
code N code L
mm Nm Nm Nm Nm Nm Nm Nm 05 5 0,08 to 0,5 0,005 to 0,06 0,08 to 0,5
06 6 0,005 to 0,06
0,12 to 0,80 0,01 to 0,2 08 8 0,12 to 0,8 0,006 to 0,08
0,02 to 0,4 10 10 0,12 to 0,8 0,008 to 0,1 0,008 to 0,1
12 12 0,12 to 0,8 0,008 to 0,1
15 15 0,01 to 0,12 0,01 to 0,12
17 17
20 20
22 22 0,25 to 1 0,015 to 0,25
25 25 0,25 to 1 0,015 to 0,25 0,25 to 1 0,015 to 0,25
30 30 0,4 to 2 0,02 to 0,4 0,4 to 2 0,02 to 0,4 0,4 to 2 0,02 to 0,4
35 35
40 40 0,03 to 0,6 0,6 to 2,7 0,025 to 0,5 0,6 to 2,7 0,025 to 0,5
45 45 0,6 to 2,7 0,03 to 0,6 0,03 to 0,6
50 50
55 55
SIST EN 2755:2009



EN 2755:2009 (E) 14 Table 3 — Starting torques without load for bearings, inch series
Diameter Inch series Starting torque without load
EN 4613 EN 4614 EN 6096 Code Nominal normal reduced normal reduced normal reduced
code N code R code N code R code N code R
mm Nm Nm Nm Nm Nm Nm 03 4,826 0,06 to 0,34 0,0 to 0,11 0,06 to 0,56 0 to 0,11 0,06 to 0,34 0 to 0,11 04 6,35 0,11 to 0,56 0,11 to 0,56 0,11 to 0,56 05 7,937 06 9,525 07 11,113 0,03 to 0,15 0,03 to 0,15 0,03 to 0,15 08 12,7 09 14,288
10 15,875 0,11 to 0,56 0,03 to 0,15 12 19,05 14 22,225 0,23 to 0,90 0,04 to 0,25 0,23 to 0,90 0,04 to 0,25 0,23 to 0,90 0,04 to 0,25 16 25,4 20 31,75 0,23 to 1,50 0,05 to 0,32 0,23 to 1,50 0,05 to 0,32 0,23 to 1,50 0,05 to 0,32 24 38,1 0,11 to 0,32 28 44,45 32 50,8
SIST EN 2755:2009



EN 2755:2009 (E) 15
Key 1 Plastic encapsulation 2 Bearing 3 Liner Figure 1 SIST EN 2755:2009



EN 2755:2009 (E) 16 Table 4 — Maximum permanent deformation after load for bearings, metric series
Dimensions in millimetres Diameter Maximum total deflection under load Maximum permanent deformation after load code nom. EN 2584 EN 4038 EN 2585
EN 4039 EN 3048 EN 4037 EN 4040
Cs Cs Ca Cs Ca Cs Ca Cs Ca 05 5 0,25 0,08 0,12 0,08 0,12
06 6
0,08 0,12 08 8
10 10 0,37
12 12 0,08 0,12
15 15 0,43
17 17
20 20 0,5
22 22 0,08 0,12
25 25 0,08 0,12 0,08 0,12
30 30 0,75 0,1 0,14 0,1 0,14 0,1 0,14
35 35
40 40 0,12 0,16
45 45 1 0,12 0,16 0,12 0,16
50 50
55 55
Table 5 — Maximum permanent deformation after load for bearings, inch series Dimensions in millimetres Diameter Maximum total deflection under load Maximum permanent deformation after load code nominal EN 4613 EN 4614 EN 6096
Cs Cs Ca Cs Ca Cs Ca 03 4,826 0,25 0,08 0,12 0,08 0,12 0,08 0,12 04 6,35 05 7,937 06 9,525 0,37 07 11,113 08 12,7 09 14,288 0,43
10 15,875 0,08 0,12 12 19,05 0,5 14 22,225 16 25,4 20 31,75 0,75 0,1 0,14 0,1 0,14 0,1 0,14 24 38,1 0,12 0,16 0,12 0,16 28 44,45 1 0,12 0,16 32 50,8
SIST EN 2755:2009



EN 2755:2009 (E) 17 Table 6 — Maximum permissible liner wear
Test under dynamic radial loads Maximum permissible liner wear C25 mm At ambient temperature 0,115 At low temperature 0,2 At elevated temperature 0,15 At ambient temperature after immersion in the fluids
Table 7 — Maximum starting torques under load for bearings metric sizes after test at ambient temperature
Diameter Maximum starting torque under load code nominal EN 2584 EN 4038 EN 2585 EN 4039 EN 3048 EN 4037 EN 4040
mm Nm Nm Nm Nm 05 5 3,41 8,64
06 6 5,6
10,34 08 8 7,94 10,34
18,03 10 10 11,25 18,03
35,68 12 12 21,28 35,68 11,16
15 15 42,55 48,77 24,35
17 17 54,68 60,16 35,96
20 20
90,55 60,35
22 22 129
25 25 158 296 100
30 30 245 391 146
35 35 353 484 223
40 40 476 564 307
45 45 667 760 458
50 50 883 957
...