1 Shaft seal HUDSON & COMPANY | Shaft seal Installation GUIDEI ntroduction..improperinstallation isthe numberone cause ofshaft sealfailure! Having given due consideration to all aspectsof the Shaft seal assembly (including thebore, the Shaft , and the design of the sealitself ), what remains is to successfully install the sealyou ve selected or as that may sound, proper Installation is notalways easy. As a matter of fact, it can be quite difficult,which explains why improper Installation is the numberone cause of Shaft seal failure!
2 With that in mind, we Hudson & Company have prepared this Shaft SealInstallation hope that it will be helpful as youinstall Shaft seals. Keep in mind that good installationpractices include inspection of the seal and other com-ponents just prior to Installation , use of the properequipment during Installation , and protection of theassembly after Installation . If you have questions, pleasecall us. We ll do whatever it takes to make sure you getthe sealing solutions you seal HUDSON & COMPANY | Shaft seal Installation GUIDEPre- Installation .
3 No matterwhere it islocated, anydamage shouldimmediatelydisqualify anew sealfrom use. Because it is the most important part of theseal, the sealing lip should be closely inspect-ed to make sure there are no nicks or tears atany point around its circumference. You should alsobe certain that the lip is not turned back. Either atorn or turned lip will quickly fail in the seal design incorporates a garter spring, you shouldcheck to be sure that the spring hasn t been displacedout of its groove as a result of handling.
4 The seal also be free of damage such as cuts, dents, orscores. No matter where it is located, any damage shouldimmediately disqualify a new seal from use. And becausedamage (especially the hard-to-see variety) can resultfrom service, you should never reinstall a used even the smallest amount of outside contami-nation can be detrimental to a sealing system, new sealsthat have passed inspection should still always be wipedclean prior to the seal itself, the bore (and housing) should alsobe carefully examined.
5 Housing edges must be free of burrsor other imperfections that can easily damage the ofan incoming seal . The edges of the bore must be burr- andnick-free. The bore roughness andchamfer must meet RMA and SAEguidelines as shown in Figure Shaft should be inspected toensure there are no nicks or burrs, andit should be finished to RMA (RubberManufacturing Association Publications OS-1 and OS-1-1) stan-dards as listed in Ta ble chamferof the Shaft should also be free ofnicks or burrs, and it should follow therecommended guidelines as shown inFigure all, keep in mind thatBORE DIMENSIONSF igure 1.
6 Bore chamfer, radius, and surfacefinish recommendationsThis Corner must be Burr-Free15 to inch( - )R .030 inch( mm)Finish 125 U inch RAor less ( UM)This corner mustbe in( mm) Shaft seal installationPRE- Installation HUDSON & COMPANY | Shaft seal Installation GUIDEa new seal should never be run in the same Shaft weartrack as an old grooving of the Shaft surface exists from previousservice, three options are available. A spacer can beplaced within the bore (behind the seal ) in order tomake sure the seal contacts an ungrooved portion ofthe , ametallic wearsleeve may befitted over(and, if needbe, adhered to)the damagedshaft to pro-vide a moresuitable seal -ing surface.
7 Use of a thin-walled sleeve will normallymake it possible to thus retrofit a damaged Shaft surfacewithout changing the seal dimensions or design. Insome cases, it may be necessary to refinish or replacethe DIMENSIONSF igure 2: Shaft chamfer and radius recommendationsR . 125 inch( mm)The Shaft corners must be burr-free15 to inch( - )PARAMETERG rinding Chatter(OOR) Out of RoundnessShaft LeadRa (Surf. Roughness Avg.)Rz (Average Peak-to-ValleyHeight)Rpm (Average Peak-to-Mean Height)Instrument ParametersSAE J946 (1991)(CONF.)
8 TO ISO 6194/1)Not SpecifiedNot SpecifiedLess than 0 +/- m (10-20 in)Not SpecifiedNot mm ( in) cutofflengthRMA 0S-1 (1985) & OS-1-1 (1999)None allowed > 45 cycles (lobes)> mm ( in) at a max. of 2lobes> mm ( in) at a max. of 7lobesLess than 0 +/- m (8-17 in) m (65-115 in) m (20-50 in) mm ( in) cutoff length 5 m ( in) 90 diamond stylus tipradiusM-1 digital Gaussian filterTable 1: Shaft Surface Finish SpecificationsSHAFT SURFACE FINISH Shaft seal HUDSON & COMPANY | Shaft seal Installation GUIDEI nstallation.
9 But even if it sfacing the rightdirection, theseal must also beinstalled at a right angle (perpendicular)to the center-lines of both theshaft andthe bore . Because a Shaft seal should never run withoutproper lubrication, both the seal lip and theshaft should be lubricated (typically with thesame oil or grease being sealed) prior to Installation ofthe seal . In addition to making the Installation botheasier and less potentially damaging to the seal , lubri-cation also helps protect the sealing element duringthe initial break-in period.
10 Continued lubrication min-imizes wear and maximizes service 3shows a double lip seal packed with greasebetween the primary and secondary lips. When two sealsare installed in tandem, the entire space between thetwo seals may be packed with grease. Insome cases, seal suppliers will pre-lubeseals upon obvious as it may sound, care must betaken to install the seal in the right direc-tion. If replacing a previously used seal ,be sure to note the direction in which theprimary lip of the old seal was facing,then ensure that the primary lip of thenew seal faces the same way.