Engineering Data of Rod Ends - Part Two

7. TOLERANCE AND FIT

7.2 Tolerance & Fits for Rod ends

Inner ring

The Đdmp,△Bs of Sl…E,SI…ES,SA…E,SA…ES,SIR…ES,SIQ…ES,SK…ES,SF…ES,SI…C,SA…C,SI…ET-2RS,SA…ET-2RS are same as  radial spherical  plain  bearings  GE…E,GE…ES,GE…C,GE…ET-2RS

The △dmp,△Bs of SIGEW…ES are same as radial spherical plain bearings GEEW…ES.PHS…,POS…,PHSB…,POSB…,PHS…EC,POS…EC,PHS…HD,POS…HD,NPHS…,NPOS…,SPHS…,SPOS…,SPHS…EC,SPOS…EC,SCHS…SCOS.

Center height deviation (mm)

Tolerances for American size rod ends are indicated in each table enclosed.

8. Bearing Internal Clearance

Bearing internal clearance is defined as the total distance through which one ring can be moved radially (radial internalclearance)or axially (axial internal clearance)in relation to the other ring under a defined measuring load.

It is necessary to distinguish between the internal clearance of a bearing before it is mounted and the internal clearance of  a  mounted  bearing  when  in  operation  (operational clearance).The  initial  clearance  will  always  be  greater  than  the operational clearance because the rings are expanded or compressed by interference fit and as a result of the differences in thermal expansion of the bearing rings and mating components.

The  bearing  internal  clearance  referred  to  as  normal  has  been  selected  so  that  when  bearings  are  mounted  generally recommended and operate under normal conditions a suitable operational will be obtained. For other conditions,e.g.where both  rings  are  mounted  with  an  interference  fit  or  where  unusual  temperatures  prevail,bearing  with  greater  or  smaller internal clearance than normal may be required.

8.1 Radial internal clearance of radial spherical plain bearings

Radial internal clearance of steel-on-steel radial spherical plain bearings

Series of  GE…E, GE…ES, GE…ES-2RS, GEEW…ES, GEEM…ES, GEZ…ES, GEZ…ES-2RS, COM.., COMH…, COM…SS, MIB,AIB,SIB

Series of GEG…E, GEG…ES, GEG…ES-2RS

Series of GEBK…S

Series of GE…C,GE…PW,COM…T,COM…H,COMSS…H,WSSB.…,WSSB…V,NSSB.…,NSSW…V, YSSB…,YSSB.V,MIB…AIB…,SIB … .

Series of GE…ET-2RS, GE…XT-2RS

Series of GEG…ET-2RS,GEG…XT-2RS

8.2 Radial intenal Clearance of Rod ends

Series of Sl…E,SI…ES,SA…E,SA…ES,SIR…RS,SIGEW…ES,SIQ…ES,SK…ES,SF…ES,CM …, CF…,,JM…,JML…JF…,JFL…,RJM…,RJF…ALJM…,ALJF…,ALRSM …

Series of Sl…C,SA…C,SI…ET-2RS,SA…ET-2RS,CHS…,COS…,SCHS…,SCOS…,NPHS…,NPOS…PHS…EC,POS.EC,SPHS…EC,SPOS.EC,SPHSB…EC,SPOSB…EC,CF…T,CM…T,SCF…T,SCM…T,,CMX…T,RJM…T, RRSMX…T,SJM…T,SRSM…T,SJF…T,HJMX…T,PMX…T,NJF…,NJM…,NXF…,NXM…,NEXF…,NEXM…, NAF…,NAM…,RSM…T,RSMX…T,HRSMX…T

Series of PHS…,POS…PHSB…,POSB…,PHS…HD,POS…HD,SPHS…,SPOS…,M…,F …

8.3 Fits of radial spherical plain bearings

Shaft fits

Housing fit

• Shaft diameter tolerances

• Housing bore tolerances

• Fits for rod ends

Shaft fits

Thread

Shaft diameter tolerances

9. Mounting

Proper  press-fitting of spherical  bearings  into  a  housing  fixture  will  result  not  only  in  smooth  bearing  performance,but also  in  better  wear  characteristics  leading  to longer  life. LDK engineering recommends strict adherence to the  following installation procedures in order to assure optimal spherical bearing performance and wear.

The spherical bearings and rod ends must be kept in their original packaging until shortly before their installation,so that they continue to be effectively preserved for as long as possible.Ensure during the installation process that foreign particles are on no account allowed to enter the outer ring of the bearing.

The  use  of  a  hydraulic  press  to  apply  constant  pressure  is  recommended.Any  other shocking-inducing device such as a hammer will result in damage and/or ultimate misfit. An installation tool such as that shown on the left is ideal.Here the guide pin aligns the ball's  bore  parallel to the  race  O.D.,while all force  is applied to the outer  race surface only.The force required for installation and removal should on no account be transmitted from the spherical form to the bearing shells or raceways of the bearing outer ring.

Customers often require a bearing with a specially formed "V"-shaped groove on the face of the outer rave,allowing for staking of the bearing into bearing into a fixed outer housing. This is accomplished by forcing the metal on the outside of the groove onto the fixture's face or into its chamfer.The use of hydraulic press for this operation is recommended, as is following the instructions for the initial installation of the bearing into the housing as described above.

LDK Engineering recommends an upper and lower anvil method for installation.Anvils should be aligned as shown,with guide pin in position.This pin should ideally be secured in the lower anvil by means of a set screw.A test assembly should  be undertaken to assure that required axial (thrust)load requirements of the final product are maintained.Avoid excessive pressure which can result in distortion leading to premature failure or malfunction.When the test requirements are met, the  assembly  should  be  rotated  at  90°maximum  intervals,with  pressure  re-applied,to  assure  uniformity  of  the  metal swaging  process.

When mounting spherical plain bearings with a fractured or two-part outer ring,it is essential that the joint should be positioned at 90°to the main load direction,otherwise the service life will be shortened,particularly under heavy loads.

To facilitate  mounting,the ends of pins or shafts and the edges of housing bores should have a lead chamfer of 10°to 20°,The bearings can be more easily pushed into position and there is little risk of damage to the mating surfaces being caused by skewing of the bearing.

10. LUBRICATION AND MAINTENANCE

10.1 General instruction

The useful life of all spherical bearings and rod ends with metallic mating materials is greatly dependent on regular lubrication. A one-off initial grease filling is only adequate if operating loads are very low.

The effectiveness of lubrication is mainly dependent on the load,type of the load (constant,pulsating or alternating),the   swivel and sliding speed.To ensure optimum and even distribution of the lubricant,initial and subsequent lubrication should be carried out with the spherical plain bearings or rod ends in an unloaded condition.

Note:

In order to avoid incompatibility of various lubricants that may be used by LDK and the  customer,spherical bearings and rod ends are supplied only with an anti-corrosive coating.For this reason,spherical bearings and rod ends which need maintenance should be given initial lubrication before commissioning or directly after installation.We recommend carrying out-initial lubrication after a running-in time of approx 1 hour.Whenever this lubrication is carried out,the bearing must be in an unloaded condition,so that the lubricant can spread without obstruction.Lubrication should continue until the lubricant emerges between the bearing outer ring and the inner ring.For rod ends with a female thread,it is also advisable to fill the space in the shank thread with lubricant up to the threaded connection journal before installation.This reduces the amount of work involved in lubricating with the lubricating nipple.

10.2   Lubrication &maintenance of spherical plain bearings

For spherical plain bearings requiring maintenance which are of the steel-on-steel type,the purpose of the lubrication is primarily to  reduce wear,reduce  friction and  prevent  scuffing.Also  the  grease serves to  protect  the  bearings  against corrosion.The frequency of relubrication of the bearing during its operation will appreciably extend the service life.

For steel-on-PTFE fabric spherical plain bearings,there is a transfer of PTFE from fabric to the opposing steel surface of  the inner ring.Any lubrication of the sliding contact surfaces would disturb this transfer and shorten bearing life.Therefore, lubrication of these bearings is not advisable.

For  steel-on-PTFE  composite  material  spherical  plain  bearings,as  a  rule,it  must  not  be  lubricated.When  operating conditions are such that enhanced sealing and protection against corrosion are required,it is recommended that the bearing or the space surrounding the bearing is filled with lithium base grease.

10.3  Lubrication &maintenance of rod ends

LDK  steel-on-steel  and  steel-on-bronze  rod  ends  have  very  wear-resistant.Sliding  surface  and  perform  well  under conditions  of  lubricant  starvation.Rod  end  with  this  sliding  contact  surface  combination   requires  regular  relubrication. LDK  maintenance-free  rod  ends  sliding  contact  surfaces   have  two  groups.Steel-on-PTFE  composite  and  steel-on-PTFE  fabric.They  have  very  low  friction  and  can  be  operated  without  maintenance.Therefore.Lubrication  of these  bearing  is  not  advisable.

10.4   GREASE  FITTING  CONFIGURATION

Catalog load ratings are based on rod ends without grease fittings.

For adjusted load ratings with grease fittings consult LDK engineering.

10.5   GREASE FITTING CONFIGURATION

• Location

Standard grease fitting locations are illustrated at the right.Note that for a female configuration,once the male threaded component is fully engaged,the grease is forced through the hole at the top of the female shank to facilitate ball lubrication.

• Standard Grease Fitting

Order by adding the letter ''z'' to the completed number.example: CM8Z

11. ACCURACY

The tolerances apply to outer ring without surface treatment and splitting.The outer rings become slightly out of round due to splitting.The roundness of the outer ring is restored once it is fitted in a housing bore produced in accordance with the specifications (Figure1).Measurements taken of the outside diameter of the unfitted bearing cannot be used as

the original actual values for the outside diameter.

12. STUD CONFIGURATION

NOTE:

• AVAILABLE ON ALL SERIES.

• SUTD MATERIAL:LOW CARBON STEEL AND ALLOY STEEL(HEAT TREATED) -ZINC PLATED.

• STUD MISALIGNMENT APPROX. +/-25°IN ANY DIRECTION.

• TO SPECIFY RIGHT HAND STUD, ADD SUFFIX"Y"TO PART NUMBER. EXAMPLE: CM6Y

• TO SPECIFY LEFT HAND STUD, ADD SUFFIX "YL"TO PART NUMBER. EXAMPLE: CM6YX

• TO SPECIFY HEAT TREATED STUD, ADD SUFFIX"YX"TO PART NUMBER. EXAMPLE: CM6YX

• FOR LOAD RAINGS WITH STUDS,PLEASE CONTACT LDK ENGINEERING DEPARTMENT.

13. WARRANTY & DISCLAIMER

13.1 Warranty

LDK warrants that the products well be free from defects in material and workmanship for one year from date of sale. LDK  makes  no  other warranty of any  kind,express  or  implied.LDK shall  have  no  obligation  under  the foregoing warranty where the  defect  is  the  result  of  improper  or  abnormal  use,negligence,vehicle  accident,improper  or  incorrect  installation  or maintenance,nor when the product has been repaired or altered in any way so as (in our judgment)to affect its its performance. LDK's liability in the case of defective products subject to the foregoing warranty shall be limited to the repair or replacement, at LDK's option,of the defective products.Except expressly provide herein,LDK shall have no liability (on account negligence or  otherwise)for,or  in  connection  with,defects  or  deficiencies  in  the  products  and  in  no  event  shall  LDK  be  liable  for  any incidental, special  or  consequential  damages  or  commercial  loss  (including  loss  revenue  or  profits)of  buyer  or  any  other person,arising  our  of the  use,or  inability  to  use,the  goods, or  the  failure  or  ineffectiveness  of  the  goods.

13.2 DISCLAIMER

LDK  reserves   the  right  to  substitute  equal  or  stronger  materials  at  their  discretion. LDK  reserve   the  right  to  change specifications  and  other   information   included  in  this   catalog  without   notice.All  information,data  and  dimension  tables   in this  catalog  have  been  carefully  complied  and  thoroughly  checked.However,no  responsibility  for  errors  or  omissions  can be  assumed.

WARNING

Since the manufacturer is unable to determine all applications in which a part may e placed, it's the user's responsibility to determine the suitability of the part of its intended use.This is especially true where safety is a factor.Incorrect application or installation may result in property  damage,bodily injury,or death.For technical assistance, please check with us.

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