75mm to 180mm SPLIT TAPERED BEARINGS

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introductionThe Cooper split tapered bearing is intended for the ‘fixed’bearing position of shafts where there is both radial and axialloading and our ‘GR’ cylindrical roller bearing is unsuitable.It is constructed with two opposed rows of rollers to takeaxial loading in either direction, and is intended to be usedwith ‘expansion’ type bearings in all other positions on theshaft.Cooper split tapered roller bearings are generally mountedin a ‘cartridge’ in a similar way to Cooper cylindrical rollerbearings. This is a spherically-machined inner housing that canbe fitted into a number of types of outer housing.The spherical seat between the cartridge and the outerhousing accommodates misalignment between the shaft andmounting structure.The cartridge also houses the seals. This ensures that the sealsare maintained concentric to the shaft, even if there is significantmisalignment of the shaft relative to the outer housing.Cartridges for tapered bearings are fitted with a holein communication with the outer race, for fitment of atemperature element, as standard. The standard hole positionis in the end face of the cartridge. The proximity of this holeto the shaft means that if the temperature element is of theheaded type, generally it will need to have a cranked probe.Alternative hole positions are possible, including radial holesrequiring additional holes in the outer housing.Outer HousingsTapered bearing in cartridgeAs the cartridge spherical seat diameters are common to theseats for Cooper cylindrical bearings, the bearing and cartridgeunit can be fitted in a wide variety of existing housing designs.However, the two types most commonly used are thepedestal (or ‘pillow block’) and flange.Pedestal CapPedestal (or ‘pillow block’)CartridgeCage and rollersOuter raceClampingringsInner racePedestalBaseSeals (variousoptionsavailable)ShaftFlangeDuctile iron pillow blocks and flanges are offered as standardwith these bearings. Please confirm load capacities of housingswith our technical department before finalising designs.
75mm to 180mmSplit tapered BEARINGsBulkhead sealingIt is often found economical to combine a bearing andbulkhead seal into one unit. This reduces the number ofindividual units required, and prevents problems with shafteccentricity sometimes encountered at the bulkhead seal whenit is separated from the bearing.Generally, a specially adapted flange mounting is used and thebearing is fitted with SRSRP seals (see page 6). Generally, theflange incorporates additional sealing to the cartridge seating,and may include sealing on the mounting face (‘backface’).Where the shaft surface speed is too high for standardSRSRP seals, an alternative high speed version is available, oralternative seal types can be used if a moderate leakage ofwater is permitted through the bearing in an emergency.Sealing to flange mounting face (“BFS”)Sealing to swivel seating (“SSE”)SRSRP SealCombined bearing and bulkhead sealBearing SelectionBearing ratings for dynamic radial capacity (Cr) and static radialcapacity (Cor) shown in this leaflet are in accordance with ISO281-1990 and ISO 76-1987 respectively.Radial and axial loads must be considered together ascombined ‘equivalent loads’, as explained below. Generally,maximum instantaneous loading is governed by housingstrength rather than bearing static capacity.Dynamic ratingExpected bearing life is calculated by the following equation:L10 = [Cr/(P x fd)] (10/3)where:L10 = expected life of 90% of similar bearingsunder similar operating conditionsCr = radial dynamic ratingP = equivalent dynamic loadfd = dynamic or service factor, generally from1 for steady loading to 3.5 for heavy shock,reciprocation or vibrationThe dynamic equivalent load is calculated as follows:when F a /F r ≤e :when F a /F r >e :P = F r + Y 1 F aP = 0.67F r + Y 2 F awhere:F r = applied radial loadF a = applied axial loadand calculation factors Y 1 , Y 2 and e are given in the productdata tables.Life calculation with multiple load conditionsWhere varying loads are experienced in operation, using themaximum load condition may lead to an unrealistically lowcalculated life. For n load conditions constituting the full loadcycle (at constant speed), an overall dynamic equivalent loadmay be calculated as follows:i=n0.3P = [∑P (10/3) i p i ]where:P ip ii=1= dynamic equivalent load under loadcondition i= proportion of time load condition i isapplicableWhere the load is continuously variable it may be brokendown into a discrete approximation to the actual load cycle.Minimum loadingIn order to avoid excessive skidding of the rollers, sufficientloading must be applied to the bearing, as follows:P ≥ 0.01Cr2
Page 1: T e c h ni c a lI n f o r m at i o
Page 5 and 6: 75mm to 180mmSplit tapered BEARINGs
Page 9 and 10: cartridge dataLL1L1L2Jw (max.)GAdAT
Page 11 and 12: FLANGESR PCD,holes equally spacedPL
Page 16: cUSTomer SerVice cenTreSGermanyCoop

75mm to 180mm SPLIT TAPERED BEARINGS

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