1、ASD Technical Report Rapport Technique ASD ASD Fachbericht TR 4541 Edition 1 April 2008 PUBLISHED BY THE AEROSPACE AND DEFENCE INDUSTRIES ASSOCIATION OF EUROPE - STANDARDIZATION Avenue de Tervuren, 270 - B-1150 Brussels - Tel. + 32 2 775 8126 - Fax. + 32 2 763 3565 - www.asd-stan.orgICS: Descriptors
2、: ENGLISH VERSION Aerospace series Instruction for the installation by staking of aerospace bearings Srie arospatiale Instructions relatives au montage par sertissage des articulations, roulements et rotules Luft- und Raumfahrt Vorschrift fr den Einbau von Flugwerklagern mittels Verstemmen This Tech
3、nical report was drawn up by ASD-STAN in cooperation with ASD-CERT. The reason which led to the publication of the document as a Technical Report is explained in the foreword. Edition approved for publication 2008-04-30 Copyright 2008 by ASD-STANPage 2 TR 4541:08-04 Contents Page Foreword3 1 Introdu
4、ction4 1.1 Scope 4 1.2 Methods of staking 4 2 Normative references 4 3 General information.5 3.1 Terms and definitions .5 3.2 Installation with clearance (and transition fit) 5 4 Tolerances between housings and bearings5 4.1 General5 4.2 Installation with interference fit5 4.3 Housing material stren
5、gth 6 5 Staking process .6 5.1 Fastening by means groove deformation on chamfer.6 5.2 Fastening by means locking bush 11 6 Staking process description 12 6.1 Staking by static pressure . 12 6.2 Roller staking 20 6.3 Segment staking . 22 6.4 Ball staking 24 6.5 Locking bush staking, bushes with or wi
6、thout grooves 25 6.6 Locking bush staking, bushes with collar or tab 29 7 Removal of spherical bearings 30 7.1 General. 30 7.2 Bearing with grooves . 30 7.3 Bearing staked by deformation of the groove of the housing . 32 7.4 Bearing staked by locking bush 32 7.5 Bearing extraction 33 8 Synthesis of
7、different staking method . 34 Page 3 TR 4541:08-04 Foreword The main task of ASD-STAN is to prepare EN standards. In exceptional circumstances, however, the publication of a Technical Report of one of the following types may be proposed: type 1, the subject is still under technical development requi
8、ring wider exposure; type 2, a Technical Domain has collected data of a different kind from that which is normally published as a European Standard. The Mechanical Domain decided to publish this document in the form of a Technical Report of type 2, as it contains only general guidelines. Technical R
9、eports are normally published in a trilingual version. Due to the volume of this document, the report is published, as an exception, in three separate language versions. Page 4 TR 4541:08-04 1 Introduction 1.1 Scope This Technical Report specifies the different types of installation of spherical bea
10、rings and rolling bearings which use various staking methods. Other installation methods are not covered by this Technical Report (bonded bearings, other mechanical restraint ). 1.2 Methods of staking Fastening by means of groove deformation on chamfer; Fastening by means of roller staking; Fastenin
11、g by means of segment staking; Fastening by means of ball staking tool; Fastening by means of locking bush; Fastening by means of locking bush with collar or tab staking. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated refer
12、ences, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 6055, Aerospace series Rod-ends with bearings per EN 4265, in corrosion resisting steel, external threaded shank Dimensions and loads, inch series. 1)EN
13、 6056, Aerospace series Rod-ends with bearings per EN 4614, with self-lubricating liner, in corrosion resisting steel, external threaded shank Dimensions and loads, inch series. 1) EN 6057, Aerospace series Rod-ends with bearings per EN 4265, in corrosion resisting steel, internal threaded shank Dim
14、ensions and loads, inch series. 1)EN 6098, Aerospace series Rod-ends with bearings per EN 6097, in corrosion resisting steel, extra wide inner ring, external threaded shank Dimensions and loads, inch series. 1)TR 4475, Aerospace series Bearings and mechanical transmissions for airframe applications
15、Vocabulary. 2)MIL-HDBK-1599A, Bearings, control system components and associated hardware used in the design and construction of aerospace mechanical systems and subsystems. 3)1) In preparation at the date of publication of this ASD Technical Report 2) Published as ASD Technical Report at the date o
16、f publication of this AECMA Technical Report 3) Published by: Department of Defense (DOD), the Pentagon, Washington, D.C. 20301. Page 5 TR 4541:08-04 3 General information 3.1 Terms and definitions For the purposes of this document, the terms and definitions given in TR 4475 apply. 3.2 Installation
17、with clearance (and transition fit) Most bearings using these types of fit are defined by standards. Dimensions and tolerance are reported in the standards or in the manufacturers specification. 4 Tolerances between housings and bearings 4.1 General The tolerances of the mating parts are agreed betw
18、een manufacturer and user. 4.2 Installation with interference fit 4.2.1 Introduction This type of installation is applied when resistance to fatigue is required. In those cases of installation with interference fit, the allowable range of interference must be defined by a specification issued by the
19、 user or by the manufacturer. 4.2.2 Interference check The interference must be computed by measuring the actual dimensions of each bearing and housing pair. 4.2.3 Installation with light interference fit The interference value must be lower than the radial play of the bearing in installation with i
20、nterference fit (ball bearings, spherical bearings metal/metal), in order to prevent seizures, distortion or high friction. 4.2.4 Friction torque modification before and after staking of self lubricated spherical plain bearings The friction torque changes with the staking load as shown in Figure 1 a
21、nd of the interference. The staking process is correct if the final friction torque value is lower than twice the value measured before the installation (for light interference fitted bearings). Page 6 TR 4541:08-04 Key A Maximum friction torque value allowed for a correct installation B Friction to
22、rque value before the installation P Staking load T Friction-torque Figure 1 Example of friction torque change 4.3 Housing material strength The material strength of housing must be considered in installations with grooves in the bearings. 5 Staking process Several staking procedures may be applied.
23、 The selection of the most suitable procedure is made on the basis of the shape (with or without grooves) of the bearing and of the material both of the bearing and the housing. Also the same procedure may be applied in a different way from one user to another. Some users apply different staking pro
24、cedures according to the bearing and housing materials. 5.1 Fastening by means groove deformation on chamfer 5.1.1 Staking by static pressure deformation The staking of bearing in its housing is obtained by upper and lower anvils which press out the lips of the groove by their shape. The characteris
25、tics of the completed installation must be compliant with the requirements of the applicable specifications and must be repeatable. Two conceptual design variants are provided (Figure 2 and Figure 3). The bearing is removable and replaceable (Figure 2 or Figure 3) according to the method selected. I
26、n this second option, the groove removal damages the housing. 5.1.1.1 Grooves in the outer race of bearing Bending of the outer lips of the grooves of the outer race of the bearing against the chamfer of the housing. Page 7 TR 4541:08-04 Key A Staking tool E Outer ring B V-shape groove F Lip to be b
27、ent C Outer ring side face G Chamfer D Inner ring H Housing Figure 2 Grooves in outer race of bearing 5.1.1.2 Grooves in the housing Bending of the lips of the grooves of the housing against the chamfer of the outer race of the bearing. This method of staking allows only one installation. Its use is
28、 forbidden with all those materials that are notch sensitive. This method must be avoided for new designs. Key A Staking tool E Ring lip of housing to be bent B Deburred, no chamfer F V-shape groove C Chamfer G Housing D Outer ring Figure 3 Grooves in the housing This staking method may be used only
29、 if the hardness of the outer race of the bearing does not allow the lips of grooves in the bearing to be beat against the housing. Page 8 TR 4541:08-04 5.1.2 Fastening by means of roller staking The same concept as for anvil staking is applied, but the deformation of the lips of the grooves is obta
30、ined by a rotating tool instead of by static pressure. The lip is rolled outwards against the chamfer. The rolling of the lips must be done on both sides of the bearing. 5.1.3 Fastening by means of segment staking This method of staking, shown in Figure 4, allows only one installation. Its use is fo
31、rbidden with all those materials that are notch sensitive. This method must be avoided for new designs. Dimensions in millimetres Before staking After staking Key A Housing B and D Dimensions are reported in bearing standards C Segment impression depth Figure 4 Example 5.1.4 Fastening by means of ba
32、ll staking tool Bearing retention is obtained by a ball staking tool. The ball impressions clamp the bearing. This kind of installation cannot withstand an axial load. This is only a means of keeping the bearing in place. Balls with different diameter may be used ( 2, see Figure 5 and 4, see Figure
33、6). Page 9 TR 4541:08-04 Dimensions in millimetres Before staking After staking Key A The ball impression depth will be defined on the basis of used material. C and D Dimensions are reported in bearing standards. P Step 5 mm to 10 mm (approx.). Figure 5 Example with balls of 2 (applicable to small b
34、earings) Page 10 TR 4541:08-04 Dimensions in millimetres Key C Outer ring width C + 1 Housing thickness D Outer diameter of ball or spherical bearing D and C Dimensions are reported in bearing standards R Outer ring chamfer W Location of the centre of the impression with reference to the diameter D
35、Variable on the basis of D Figure 6 Example with balls of 4 Page 11 TR 4541:08-04 5.2 Fastening by means locking bush 5.2.1 Locking bush staking See Figure 7. This method is applicable only with bearings with a chamfered outer ring in chamfered housings. The locking bush is swaged at both sides. bef
36、ore after Key A Outer ring of bearing B Locking bush of suitable material C Housing Figure 7 Example 5.2.2 Locking bush with collar or tab staking See Figure 8. This method is similar to that one described in 5.2.1, with the exception of the bush, which has a collar or tabs. before after Key A Outer
37、 ring of bearing B Locking bush of suitable material C Housing D Ring Figure 8 Example Page 12 TR 4541:08-04 5.2.3 Locking bush with staking grooves See Figure 9. This installation utilises a bush made of stainless steel with grooves at each end, where both lips are bent and staked on the outer race
38、 of the bearing and on the housing respectively. This installation can withstand an axial load whose value has the same value as for the circular staking of the outer race of the bearing. before after Key A Outer ring of bearing B Housing C Locking bush with grooves Figure 9 Example 6 Staking proces
39、s description 6.1 Staking by static pressure 6.1.1 Operating procedure protective treatment of the housing dimensional and torque check of the bearing and its housing cleaning of bearing and of its housing application of bonding agent or chilling by nitrogen liquid application of protective products
40、 bearing insertion by press tool metallic burr removal check of bearing axis alignment check of freedom of movements Page 13 TR 4541:08-04 lubrication of groove or of tool first side staking second side staking or simultaneous staking of both sides post staking inspection: dimensional, visual, frict
41、ion torque check post staking treatment (if required by user) marking of bent lips by painting (if required by user) 6.1.2 Protective treatment of the housing The protective treatment of the housing, such as anodising or others, must be completed before the bearing installation. 6.1.3 Dimensional an
42、d torque check of the bearing (pre-installation inspection) 6.1.3.1 Bearing and housing Both bearings and housings must be inspected to check that the relevant dimensions are compliant with the requirements of the applicable technical documents. 6.1.3.2 Friction torque and play The torque values wit
43、hout load and the play of the installed bearing must be compliant with the requirements of the applicable technical specification. 6.1.3.3 Chamfers The chamfers must be compliant with the requirements of the applicable technical documents. 6.1.4 Cleaning of bearing and of its housing The cleaning mu
44、st be carried out in accordance with the users specification. 6.1.5 Metallic burr removal The housing must be smooth and without contamination. 6.1.6 Installation with adhesive It allows the installation to achieve a tight fit without chilling the components. Some commercial products are characteris
45、ed by lubricant properties at installation and bonding power when the installation is completed. 6.1.7 Differential temperature installation This installation is used only to obtain high interference fits. This technique avoids (or reduces) the possible damage due to a high interference. It is recom
46、mended that this technique is not applied at a lower temperature than the operative one allowed for the bearing use. Page 14 TR 4541:08-04 6.1.8 Installation with interference See Figure 10. Key A Insertion load B Spigot C Anvil D Staking tool E Housing Figure 10 Example of a tool for bearing insert
47、ion 6.1.9 Check of bearing axis alignment with housing before its staking 6.1.10 Check of torque friction and play The friction torque and the play without applied loads must be compliant with the appropriate technical specifications. 6.1.11 Lubrication Optionally a lubricant (without MoS2, because
48、of painting adhesion) may be applied on the groove of the housing or of the bearing and/or on the staking anvil. Page 15 TR 4541:08-04 6.1.12 Staking The staking load must be compliant with the applicable documents. The staking may be performed in a single stage or in two stages (see Figures 11 to 1
49、3). correct incorrect Figure 11 Location of the bearing inside its housing Key A Staking load B Press piston C Staking tool D Housing E Staking tool F Spigot G Bearing ball H Press piston Figure 12 Example: staking in a single stage Page 16 TR 4541:08-04 Key A Staking load B Press piston C Staking tool D Housing E Anvil F Spigot G Bearing ball H Press piston NOTE After the first stage of staking, the lower anvil is replaced with the second staking head. If the tool has been reversed, ma
