skf deep groove ball bearings for extreme temperatures cut ... · is mandatory, an skf deep groove...

SKF deep groove ball bearings for extreme temperatures cut machine life cycle costs

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Contents

1 Product information ................................................... 3

Fit and forget .................................................................. 3Why SKF extreme temperature bearings are the perfect choice................................................................ 3

Comprehensive, unrivalled range ................................ 4Customised for special purposes .................................. 6Accessories for optimum performance.......................... 6

The design makes all the difference ............................ 7

2 Recommendations ..................................................... 8

How to decrease life-cycle cost.................................... 8Application examples .................................................... 8

Selection of bearing size ...............................................10Kiln truck wheel bearing arrangement design ............12Mounting, dismounting and maintenance ...................14

Mounting .......................................................................14Dismounting ..................................................................14Maintenance..................................................................14

3 Product data................................................................15

Bearing data – general...................................................15Bearing tables ................................................................16

Bearings d 12 – 35 mm.................................................16Bearings d 40 – 60 mm.................................................18Bearings d 65 – 120 mm...............................................20

The SKF Group – a worldwide corporation ............... 22

Made by SKF® stands for excellence. It symbolises our consistent endeavour to achieve total quality in everything we do. For those who use our products,“Made by SKF” implies three main benefits.

Reliability – thanks to modern, efficient products, based on our worldwide application know-how, optim-ised materials, forward-looking designs and the most advanced production techniques.

Cost effectiveness – resulting from the favourable ratio between our product quality plus service facilities,and the purchase price of the product.

Market lead – which you can achieve by taking advantage of our products and services. Increased operating time and reduced down-time, as well as improved output and product quality are the key to a successful partnership.

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1 Product information 2 Recommendations 3 Product data

Customer benefits Page ............. 8 Page ............. 15

� Doubly shieldedThe extreme temperature bearingscan be fitted with protective shields,one on each side, to prevent ingressof solid contaminants and to keepthe lubricant in place.

� Environmentally safeThe SKF extreme temperature bear-ings use environmentally friendlymaterials and do not emit any haz-ardous products provided that theirmaximum allowable operating tem-perature is not exceeded.

Wherever very high or very low environ-mental temperatures are a limiting fac-tor, a special bearing is normally need-ed. The application requirements – lowfriction and high radial loads – definethe basic design concept as a deepgroove ball bearing.

If the application is demanding andreliable operation under all temperatureconditions including extreme operatingtemperatures with low operation costsis mandatory, an SKF deep groove ballbearing for extreme temperatures isdefinitely needed.

Why SKF extremetemperature bearingsare the perfect choiceTotal quality is a must in modern indus-try. The SKF philosophy has alwaysbeen to satisfy customer needs andtotal quality is a natural part of SKFbearing design. This means that SKFtoday has a very comprehensive rangeof extreme temperature bearings interms of

� low life-cycle cost� long service life� high reliability� minimised maintenance

These benefits make SKF extremetemperature bearings the very founda-tion of trouble-free operation and totalquality. These bearings are truly excep-tional. They are the perfect choicebecause of their attractive combinationof benefits:

� Extended service lifeSKF extreme temperature bearingsare designed to give extended servicelives with a minimum of mainten-ance. SKF is the only bearing manu-facturer using graphite cage techno-logy, thus eliminating the need for anymaintenance or service whatsoever.

� Very wide operating temperaturerangeSpecial lubricants make it possibleto use some of the bearings down to–150 °C and up to a maximum oper-ating temperature of +350 °C.

Fit and forget

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Comprehensive, unrivalled range

dangerous gases or vapours are emitted.

2. 2Z/VA208 design – for highdemandsThese bearings differ from the VA228design only in their cage. Instead of thecoronet cage, they have a segmentedcage of graphite. The segments separ-ate the balls and also provide the ne-cessary lubrication. The bearings are fitted with two shields which axiallyguide the cage segments and preventthe entry of solid contaminants. Be-cause of the segmented cage, thesebearings are primarily intended forslowly rotating applications.

3. VA201 design – for the most common applicationsThese bearings are not sealed andhave a pressed steel cage. The radialinternal clearance is four times C5. All bearing surfaces are manganesephosphated. This protects the bearingfrom corrosion, enhances running prop-erties and provides good adhesion for the lubricant.

The extreme temperature bearingsof the VA201 design are lubricated witha polyalkylene glycol/graphite mixturewhich can be used at temperaturesbetween −40 and +250 °C. At tempera-tures above +200 °C, dry lubricationpertains.

4. 2Z/VA201 design – added protection with shieldsThese bearings are of the same designas the VA201 bearings but have pro-tective shields at both sides to preventthe ingress of solid contaminants.Additionally, these bearings have twice the amount of the polyalkyleneglycol/graphite mixture as the openbearings.

The range of SKF extreme tempera-ture bearings covers deep groove ballbearings in the 60, 62 and 63 series currently in demand, in sizes from 10to 100 mm bore diameter. Taking avail-ability into account, this constitutes themost complete range on the market.All bearings are available with cylin-drical bore to suit most types of mounting methods.

SKF extreme temperature bearingsare available in five different final vari-ants:

1. 2Z/VA228 design – for top requirementsThis bearing variant is the “top-of-the-line” among SKF products for extremetemperatures. It is fitted with the re-cently developed “coronet” cage ofpure graphite which makes the bear-ings suitable for new applications. Thecage can support appreciably heavierloads than the graphite segment cage.This means that in practice these bear-ings are suitable for applications wherethe operating temperature is in therange −150 to +350 °C and the speedsare up to 100 r/min.

The coronet cage is an SKF develop-ment and only available in SKF bear-ings. It not only separates the balls butalso presents a unique lubrication sys-tem. The minute quantities of graphitepowder released by the cage duringrotation provide adequate lubricationfor the bearing. The bearing is alsoequipped with two shields which pre-vent particulate contamination fromentering the bearing and also guidethe cage axially.

All surfaces of the bearing, includingthe shields, are manganese phosphatedto protect against corrosion and also toenhance running properties. The radialinternal clearance is four times C5. An-other advantage of these bearings isthat they are environmentally friendly.Even at maximum temperatures, no


Product range Page ............. 8 Page ............. 15

General ruleThe SKF extreme temperaturebearings are primarily intended forshaft speeds up to approximately100 r/min. For applications withhigher speeds or different oper-ating conditions, please contactSKF for advice and support.

5. 2Z/VA216 – for aggressive environments For bearing arrangements where theenvironment is particularly aggressive,bearings of the 2Z/VA216 design arerecommended. These bearings arecharged with a creamy-white multi-purpose grease based on a fluorinatedpolyether oil mixed with PTFE for operating temperatures from −40 to+230 °C. Otherwise the bearings havethe same design as 2Z/VA201.

For normal cases, the lubricant fill is between 25 and 35 % of the freespace in the bearing. On request other filling grades can be supplied(expressed as % of the free space inthe bearing):

10 to 15 % (suffix A)45 to 60 % (suffix B)70 to 100 % (suffix C)

VA228 VA201

2Z/VA2012Z/VA216

VA208

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Customized for specialpurposesSKF extreme temperature bearingsare designed for the most commonextreme temperature applications, e.g.kiln truck wheels, support rollers andgeneral wheel arangements.

Specific customer requirements aresatisfied by special order bearings.SKF can supply extreme temperaturebearings which can replace the exist-ing bearing design or which are thedirect result of a joint design coopera-tion with the customer. SKF has a longtradition of supplying special featurebearings for especially demandingapplications.

Y-bearing units for extreme temperaturesThe SKF product range also includes Y-bearing units for operating tempera-ture range −150 to +350 °C. They areavailable as

• Y-bearing plummer block units, • Y-bearing flanged units with square

housing, and• Y-bearing flanged units with oval

housing

Accessories for optimumperformanceThe boundary dimensions of the SKFextreme temperature deep groove ballbearings of the 60, 62 and 63 seriesare in accordance with the ISO Dimen-sion Plan. The bearings of series 62can be used directly in SKF housingsof TVN design. These housings areavailable in five sizes for shafts of 35 up to 65 mm diameter. In order tofurther protect the bearing, a heat resistant seal strip made of aluminumboron silicate can be used to preventthe ingress of contaminants from thesurrounding environment. For moreinformation please contact SKF.

The surfaces of the grey cast iron hous-ings are coated with zinc and yellowchromate; this galvanised layer pro-vides added protection against corro-sion and gives the housings a distinct-ive appearance.

To meet the widely differing engineer-ing demands in this wide temperaturerange, two different versions of bear-

ings of seriesYAR 2-2FW areused: VA201 and VA228.

The range of Y-bearing units is for shaft diam-eters of 30 to 60mm and 3/4to 2 7/16 in.

Full details will be found in brochure 4415”SKF Y-bearingunits for extremetemperatures”.


Product range Page ............. 8 Page ............. 15

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SKF extreme temperature bearingswith suffix 2Z/VA208 have a segmentedcage made from special graphite. Thebearing also has two shields which willprotect the bearing from particulatecontamination as well as keep thegraphite powder inside the bearing.Powdered graphite is slowly trans-ferred from the cage segments to thebearing surfaces ensuring constantlubrication and long service life. Nomaintenance is required.

SKF extreme temperature bearingsof the 2Z/VA228 design represent thelatest development. They are fittedwith a one-piece graphite cage insteadof the segmented cage. Tests, both atlow and high speeds (up to the max-imum recommended) have shown ex-tremely little wear. The service life hasbeen appreciably extended as the cagehas an optimum fit round the balls andthus has a low specific load. The de-sign has very high performance andoffers the longest service lives of allthe present extreme temperaturedesigns.

The design makes all thedifference


Design features Page ............. 8 Page ............. 15

The various designs of SKF extremetemperature bearings are made withthe customers needs and require-ments in mind

� Extended service life � Different lubrication systems � Customised designs� Different seal arrangements� Operational cost savings

The philosophy behind SKF extremetemperature bearings is based on con-tinuous development aiming at ruggedand reliable bearings which can beused even in the most demandingapplications. SKF extreme temperaturebearings can often be used instead ofexpensive special bearings or intricate,extremely costly lubricants offered onthe market.

The SKF extreme temperature bearings with the suffix VA201 offer thecustomer extended service life sincethe amount of lubricating paste is large,thus ensuring a good supply and anadequate reservoir of lubricant. Whenthe bearing is fitted with two protectiveshields, 2Z/VA201, the amount of lubri-cant is even larger. This together withthe shields will further prolong the ser-vice life. The shields also serve toretain the lubricant inside the bearing.

2Z/VA228 design

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can be found in many other industrieswhere bearings are subjected toextreme temperatures.

One of the main reasons for SKF’sdominant market position for extremetemperature bearings is the customers’ever increasing awareness about whatbearing quality means to their machinelife cycle cost.

How to decrease life-cycle costs


Page ............. 3 Application examples Page ............. 15

Long service life, high reliability andminimal maintenance requirementshave made SKF extreme temperaturedeep groove ball bearings the obviouschoice in all industrial segments wheretemperatures are very high or very lowand speeds low and where high run-ning accuracy is not required. The keysegments with their typical require-ments are listed below, but applications

Application examplesFoil calendersThe calenders were originally fitted withbearings which required frequent relubri-cation with expensive high temperaturegrease. Three have now been convert-ed to SKF deep groove ball bearings of the VA228 design which require nomaintenance. As a result, maintenancecosts have been reduced by more than1,2 million SEK per annum. In addition,the foil produced is much cleaner (nolubricant leakage to soil it).

Kiln trucksThe wheels are fitted with SKF deepgroove ball bearings of the 2Z/VA208design. Normal operating temperatureis +200 to +230 °C. The original bear-ing design lasted between 3 monthsand one year but with the 2Z/VA208design the service life could be extend-ed to more than 4 years. Service livesof up to more than 12 years have beenrecorded in other similar applications.This means much lower bearing costsand also no wheel repairs wererequired.

Kiln truckFoil calender

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Wafer biscuits baking ovenThe traditional wheel bearing designused standard deep grove ball bear-ings lubricated with a very expensivehigh temperature grease. The operat-ing conditions with temperatures up to +240 °C warranted relubrication atregular intevals and frequent bearingreplacement due to clogged/dried outgrease plus corrosion. The normal ser-vice life was around 2 years. Extremetemperature bearings 2Z/VA208 wereinstalled instead allowing a four-yearperiod of maintenance-free operation.

Chain grate furnace2 500 special SKF support rollersbased on double row deep groove ballbearings fitted with graphite segmentcages, design VA208, are used per furnace at operating temperatures upto +350 °C.

The original design wore out rapidlyand increased the running friction dra-matically. All rollers had to be changedwithin a year. The new SKF supportrollers kept a very low coefficient offriction and lasted up to 4 years withoutmaintenance.

SolutionSegments

� Bricks & tiles� Ceramics� Steel � Food � Autoclaves� Materials handling � Waste disposal

Requirements

� Long service life � Application-adapted

performance� Minimum mainten-

ance� High availability� Technical support


Page ............. 3 Application examples Page ............. 15

Tunnel furnaceThe rollers operate at about +350 °Cand carry the material to be heat treat-ed. During a refit the original bearings,which had a service life of approxi-mately 3 to 6 months, were replacedby SKF deep groove ball bearings ofthe 2Z/VA208 design, thus extendingthe service life to more than 7 years.

Overall operating costs have beenconsiderably reduced as a result and ithas also been possible to dispensewith the original water cooling of thehousings.

Tunnel furnace Chain grate furnaceWafer biscuits baking oven

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Page ............. 3 Calculation Page ............. 15

bearing can be selected from the bear-ing tables (from page 16 onwards). If the requisite basic static load ratinglies between two values in the bearingtable the bearing with the higher ratingshould be chosen.

Selection of bearing size for kilntruck wheelsBearing size is selected on the basis of the basic static load rating as kilntrucks operate at very slow speeds.For free wheels with two bearings ofequal size (➔ fig , page 13) the re-quisite basic static load rating for onebearing is obtained from the equation

G0C0 = 1,5 ––fT

whereC0 = requisite basic static load rating

of a single bearing, NG0 = radial load acting on one wheel, NfT = temperature factor (➔ table )

Table applies to arrangements com-prising two bearings of the same sizemounted symmetrically with respect tothe plane of the load and gives the re-quisite basic static load rating depend-ing on wheel load and temperature,calculated using the above equation,for one bearing.

For a free-wheel arrangement withbearings of different size (➔ fig ,page 13) the requisite value of C0 forthe inboard (tyre rim) side is obtainedfrom

G0C0 = 2 ––fT

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Influence of operating temperatureAt high temperatures, the load carryingcapacity of the bearings is reduced.This is taken into consideration by multiplying the basic static load ratingC0 by a temperature factor fT. Values of this factor at different temperatureswill be found in table .

Selection of bearing size based onthe static load ratingThe size of bearing required for a givenapplication is selected with referenceto the loads which are to be expectedand the load carrying capacity of thebearing. Bearings for extreme tem-peratures rotate at very slow speeds.Therefore, the requisite size is deter-mined based on the basic static loadrating C0. The requisite basic staticload rating can be determined using

P0C0 = 2 ––fT

whereC0 = requisite basic static load rating

of the bearing, NP0 = equivalent static bearing load, NfT = temperature factor (➔ table )

The equivalent static bearing load isobtained from

P0 = 0,6 Fr + 0,5 Fa

whereP0 = equivalent static bearing load, NFr = actual radial bearing load, NFa = actual axial bearing load, N

When calculating P0, the maximumload which can occur should be usedand its radial and axial componentsinserted in the equation above. If P0 < Fr, then P0 = Fr should be used.

Using the requisite basic static loadrating calculated from above, a suitable

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and for the outboard (cover) side, from

G0C0 = ––fT

The requisite basic static load rating ofbearings in axleboxes inside or outsidethe wheel (➔ fig , page 13) is ob-tained using the equation

G0C0 = 2 ––fT

Using the values of the requisite basicstatic load rating C0 calculated usingthe above equations, or obtained fromtable , suitable bearings of series60, 62 or 63 can be selected from thebearing tables (from page 16 onwards).

If the requisite basic static load rat-ing lies between two values in thebearing table, the bearing with thehigher load rating should always bechosen. The diameter of the journalmust always be checked with regard toits strength.

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Selection of bearing size

Wheel Requisite basic static load rating C0load for operating temperatures

150 °C 200 °C 250 °C 300 °C 350 °C

N N

3 000 4 500 4 740 5 000 5 630 7 0304 000 6 000 6 320 6 670 7 500 9 3805 000 7 500 7 900 8 380 9 380 11 700

6 000 9 000 9 470 10 000 11 300 14 1007 000 10 500 11 100 11 700 13 100 16 4008 000 12 000 12 600 13 300 15 000 18 800

9 000 13 500 14 200 15 000 16 900 21 10010 000 15 000 15 800 16 700 18 800 23 40011 000 16 500 17 400 18 300 20 600 25 800

12 000 18 000 18 900 20 000 22 500 28 10013 000 19 500 20 500 21 700 24 400 30 50014 000 21 000 22 100 23 300 26 300 32 800

15 000 22 500 23 700 25 000 28 100 35 20016 000 24 000 25 300 26 700 30 000 37 50017 000 25 500 26 800 28 300 31 900 39 800

18 000 27 000 28 400 30 000 33 800 42 20019 000 28 500 30 000 31 700 35 600 44 50020 000 30 000 31 600 33 300 37 500 46 900

22 000 33 000 34 700 36 700 41 300 51 60024 000 36 000 37 900 40 000 45 000 56 30026 000 39 000 41 100 43 300 48 800 60 900

28 000 42 000 44 200 46 700 52 500 65 60030 000 45 000 47 400 50 000 56 300 70 30032 000 48 000 50 500 53 300 60 000 75 000

34 000 51 000 53 700 56 700 63 800 79 70036 000 54 000 56 800 60 000 67 500 84 40038 000 57 000 60 000 63 300 71 300 89 100

40 000 60 000 63 200 66 700 75 000 93 800

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Page ............. 3 Calculation Page ............. 15

Operating Factortemperature fT

°C –

150 1200 0,95250 0,9300 0,8350 0,64

1Factor fT

Requisite basic static load rating C0for a deep groove ball bearing for freewheels with two bearings of the samesize

Calculation exampleA kiln truck has four wheels of the freewheel type, i.e. the axle does notrotate. Each wheel has two bearings of the same size.

Operating conditions:

Speed: Intermittent, approximately 2 r/min Load per wheel: 15 000 NTemperature: 250 °C

The requisite load rating C0 is obtainedfrom

G0C0 = 1,5 ––fT

so that

C0 = 1,5 × 15 000/0,9

C0 = 25 000 N

Thus a bearing having a basic staticload rating C0 of at least 25 000 N is required, for example, bearing 6211-2Z/VA208, which has a C0 value= 29 000 N.

Table

2Table

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Page ............. 3 Application advice Page ............. 15

D

a

Da = 4

To avoid excessive tilting forceswhich can occur, for example, if forcesact on the wheel at right angles to thedirection of travel, a ratio of 4:1 is re-commended for the wheel diameter Dto the distance between bearings a (➔ fig ). The free-wheel design in-corporating two bearings of equal size(➔ fig ) is generally used for kilntrucks with wheel loads of up to 30 kN.For heavier loads and wide gauge tracka design with bearings of different sizeshould be used, as the inboard bearingis more heavily loaded than that at theoutboard position (➔ fig ).

In addition to the free-wheel arrange-ment, kiln trucks are also fitted withaxleboxes either inside or outside thewheel (➔ fig ). For both designshousings are required which can bebolted to the frame of the kiln truck.Two bearings are needed for eachwheel set: one locating and one non-locating. The axleboxes must be care-

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Traditionally, the wheel arrangementsof conventional two-axled kiln trucks(➔ fig ) are usually designed asfree-wheel (independent) arrange-ments. Two deep groove ball bearingsare mounted directly on the journal.This design permits simple mountingand dismounting as well as easy in-spection of the bearings. Deformationof the axle or bogie under load or as aresult of temperature changes will nothave a detrimental effect on bearingperformance. The hub bore is sealedat the outboard position by a cover and at the inboard position by a seal.Labyrinth seals have proved to be themost suitable; felt seals are unable towithstand the high temperatures. Thelabyrinth seal must have a relativelylarge radial clearance to match thelarge internal clearance of the bearing. Suitable hub bore and journal toler-ances are given in table .1

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Kiln truck wheel bearingarrangement design

fully mounted so that the bearings donot become preloaded, as this wouldmake operation difficult and wouldcause premature failure. Because ofthe changes in axle length which resultfrom temperature variation, it is neces-sary to ensure that axial displacementis possible in both directions, and thatthe amount of possible displacement isequal at both sides of the non-locatingbearing.

SKF TVN housings are suitable ashousings for these wheel bearing ar-rangements. When mounting outsidethe wheel the A type (for shaft ends,with cover) should be used. The B type(for through shafts) should be used formounting inside the wheel. The stand-ard felt strips of these bearings shouldbe replaced by special strips (desig-nated FSB ..) of high temperaturematerial (graphited aluminium boronsilicate). Suitable hub bore and journaltolerances are given in table . 1

Conventional kiln truck wheel bearing arrangementRecommended ratio wheel diameter/bearing distance

1Fig 2Fig

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Page ............. 3 Application advice Page ............. 15

Application Tolerance

Free wheelsjournal g6hub bore J7

Rotating axlesjournal j6hub bore H71)

1) Tolerance D10 is recommended for autoclave trucks

Free-wheel arrangement with twobearings of equal size

Free-wheel arrangement with twobearings of different size

Axlebox inside the wheel, TVN housing, type B (non-locating side) and axleboxoutside the wheel, TVN housing, type A (locating side), respectively

Full details of TVN housings will befound in the SKF General Catalogue.

When making new designs for kilntrucks, free-wheel arrangements are tobe preferred as they have been foundto be superior in performance and alsomore economical.

1Table 3Fig 4Fig

5Fig

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MountingThe SKF deep groove ball bearings forextreme temperatures are mounted withclearance or interference fits on theshaft and in the housing. A satisfactoryradial location and an adequate sup-port can generally only be obtainedwhen one of the rings (depending onloading situation) is mounted with anappropriate degree of interference (➔ “Kiln truck wheel bearing arrange-ment design”, page 12).

When mounting the bearings, thering which is to have the tighter inter-ference fit is generally mounted first.The force needed to mount a bearingincreases considerably with increasingbearing size. Therefore, it is not gener-ally possible to press large bearings onto a cylindrical shaft or into a housingin the cold state. In this case, depend-ing on whether the interference isbetween bearing and shaft or bearingand housing, the bearing or the hous-ing should be heated before mounting.

To mount with an interference fit ona shaft the bearing should be heated toabout 80 to 90 °C above the tempera-ture of the shaft. This can be done bymeans of an SKF induction heater orin a heating cabinet. Mounting bear-ings by cooling the shaft is not recom-mended. The risk of condensationcausing corrosion is evident.

DismountingThe force required to remove a bearingis generally greater than the mountingforce, particularly if, after a long period

of service, frettingcorrosion is pre-sent. If bearingsare to be re-usedafter removal, theforce used to dis-mount them must

The same dry lubricant should alsobe applied thinly to all other shiny com-ponents of the bearing arrangement toprotect them from corrosion.

on no account be applied through therolling elements.

Extreme temperature bearings canbe removed using mechanical or hy-draulic withdrawal tools or a press.

For detailed information about suit-able mounting and dismounting tools,please refer to the SKF catalogue “The Tools for Trouble-Free Operation”.

MaintenanceSKF extreme temperature bearingsare largely maintenance free. The bear-ings of VA201 design should howeverbe inspected after some six months ofoperation. It is sufficient to open thehousing or to withdraw the wheel withbearings from the journal and to re-move contaminants using bellows.

If pressurised air is used the airstream should be weak and the air dry.Other inspection operations are gener-ally only necessary once a year or onceevery second year depending on theoperating conditions. If, however, thebearings do not rotate easily or havebecome noisy the bearing arrange-ment in question should be inspectedimmediately. In this case the bearingsmust be dismounted and after cleaningthey should be checked to see whetherthey are suitable for further use.

If there is no longer a film of dry lu-bricant on the raceways (indicated bya bright metallic shiny track) the bear-ings should be relubricated using theoriginal lubricant. The lubricant shouldbe applied to the bearing racewaysand the rings turned so that it is evenlydistributed in the bearing. It should beremembered that dry lubricants do notadhere so well to the relatively smoothraceway surfaces of a used bearing. Ifthere is damage to the raceways, roll-ing elements or cage or if there aresigns of wear or corrosion it is safer toreplace the bearings.

Please consult the SKF cata-logue “The Toolsfor Trouble-FreeOperation”.

Mounting, dismounting and maintenance


Page ............. 3 Mounting and maintenance Page ............. 15

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Bearing data – general

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DimensionsThe boundary dimensions of SKF deepgroove ball bearings for extreme tem-peratures are in accordance with thoseof the Dimension Series 10, 02 and 03as specified in ISO 15:1998.

TolerancesThe deep groove ball bearings for ex-treme temperatures are produced withnormal tolerances to ISO 492:1994.Because of the special surface treat-ment which they undergo to protectagainst corrosion and enhance runningproperties there may be some slightdeviations from the tolerances speci-fied in the above standard. However,this has no influence on their arrange-ment or performance.

Internal clearanceThe SKF deep groove ball bearings forextreme temperatures are producedwith extra large radial internal clear-ance. The actual values are given inthe bearing tables on pages 16 to 21.The clearance corresponds to aboutfour times the standardised C5 clear-ance (4 × C5).

MisalignmentBecause of the large clearance, thesespecial deep groove ball bearings cantolerate angular misalignments of theinner ring relative to the outer ring ofbetween 20 and 30 minutes of arc.This is only applicable when the bear-ings operate at low speeds as the roll-ing conditions in the bearings are un-favourable under such misalignment.

SpeedsSKF deep groove ball bearings forextreme temperatures were developedfor bearing arrangements where theywould rotate slowly, i.e. a few revolu-tions per minute. Our experience is,however, that it is possible to run thebearings at speeds up to 100 r/min. It

is advisable to contact SKF applicationengineering service if the bearings areto be used at higher speeds than thosefor which they were designed.

Design of associated componentsIt is advisable to provide some supportto the shields of bearings of the2Z/VA228 and 2Z/VA208 designs,because of the nature of the graphitecage. Therefore it is recommended thatthe housing shoulder should have adiameter which is approximately equalto or slightly smaller than dimension D2(➔ bearing tables).

If this is not possible then a loosewasher having such a bore diametershould be positioned between thebearing and the housing shoulder (➔ fig ).

For all other bearing designs theshoulder should have a bore diameternot greater than Da max.

EnquiriesWhen enquiring about the bearings for extreme temperatures it is recom-mended that, in addition to the numberof bearings required, details regardingthe application and operating condi-tions be given, for example:

1. Operating temperature2. Bearing or wheel load3. Speed4. Shaft diameter5. Wheel diameter6. Axlebox design7. Type of service, e.g. pottery kiln8. Special conditions, e.g. very dusty

environment

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Page ............. 3 Page ............. 8 Bearing data – general

Recommended means of support for shields of 2Z/VA228 och 2Z/VA208 bearings

1Fig

2Z/VA228 2Z/VA208 VA201 2Z/VA201

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Principal Basic static Radial internal Mass Designationdimensions load rating clearance

d D B C0min max

mm N µm kg –

12 32 10 3 100 100 180 0,037 6201/VA20132 10 3 100 100 180 0,037 6201-2Z/VA20132 10 3 100 100 180 0,037 6201-2Z/VA228

15 35 11 3 750 100 180 0,045 6202/VA20135 11 3 750 100 180 0,043 6202-2Z/VA228

17 35 10 3 250 100 180 0,039 6003/VA20135 10 3 250 100 180 0,039 6003-2Z/VA208

40 12 4 750 100 180 0,065 6203/VA20140 12 4 750 100 180 0,060 6203-2Z/VA228

20 42 12 5 000 112 192 0,068 6004-2Z/VA208

47 14 6 550 112 192 0,11 6204/VA20147 14 6 550 112 192 0,11 6204-2Z/VA20147 14 6 550 112 192 0,10 6204-2Z/VA228

52 15 7 800 112 192 0,13 6304/VA20152 15 7 800 112 192 0,13 6304-2Z/VA208

25 47 12 6 550 120 212 0,080 6005/VA20147 12 6 550 120 212 0,080 6005-2Z/VA208

52 15 7 800 120 212 0,13 6205/VA20152 15 7 800 120 212 0,13 6205-2Z/VA20152 15 7 800 120 212 0,12 6205-2Z/VA228

62 17 11 600 120 212 0,23 6305/VA201

30 55 13 8 300 120 212 0,12 6006-2Z/VA208

62 16 11 200 120 212 0,20 6206/VA20162 16 11 200 120 212 0,20 6206-2Z/VA20162 16 11 200 120 212 0,19 6206-2Z/VA20862 16 11 200 120 212 0,19 6206-2Z/VA228

72 19 16 000 120 212 0,35 6306/VA20172 19 16 000 120 212 0,34 6306-2Z/VA208

35 72 17 15 300 160 256 0,29 6207/VA20172 17 15 300 160 256 0,28 6207-2Z/VA20872 17 15 300 160 256 0,28 6207-2Z/VA228

80 21 19 000 160 256 0,46 6307/VA20180 21 19 000 160 256 0,44 6307-2Z/VA208


Page ............. 3 Page ............. 8 Deep groove ball bearings for extreme temperatures d 12 – 35 mm

r

r

r

r12

12

DD 2

B

d d1

3

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Dimensions Abutment and fillet dimensions

d d1 D2 r1,2 da Da ramin min max max

mm mm

12 18,2 27,4 0,6 16 28 0,618,2 27,4 0,6 16 28 0,618,2 27,4 0,6 16 28 0,6

15 21,5 30,4 0,6 19 31 0,621,5 30,4 0,6 19 31 0,6

17 22,7 31,2 0,3 19 33 0,622,7 31,2 0,3 19 33 0,6

24,2 35 0,6 21 36 0,624,2 35 0,6 21 36 0,6

20 27,2 37,2 0,6 23,2 38,8 0,6

28,5 40,6 1 25 42 128,5 40,6 1 25 42 128,5 40,6 1 25 42 1

30,3 44,8 1,1 26,5 45,5 130,3 44,8 1,1 26,5 45,5 1

25 32 42,2 0,6 29 43 0,632 42,2 0,6 29 43 0,6

34 46,3 1 30 47 134 46,3 1 30 47 134 46,3 1 30 47 1

36,6 52,7 1,1 31,5 55,5 1

30 38,2 49 1 34,6 50,4 1

40,3 54,1 1 35 57 140,3 54,1 1 35 57 140,3 54,1 1 35 57 140,3 54,1 1 35 57 1

44,6 61,9 1,1 36,5 65,5 144,6 61,9 1,1 36,5 65,5 1

35 46,9 62,7 1,1 41,5 65,5 146,9 62,7 1,1 41,5 65,5 146,9 62,7 1,1 41,5 65,5 1

49,5 69,2 1,5 43 72 1,549,5 69,2 1,5 43 72 1,5


Page ............. 3 Page ............. 8

daDa

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2Z/VA228 2Z/VA208 VA201 2Z/VA201

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Page ............. 3 Page ............. 8 Deep groove ball bearings for extreme temperaturesd 40 – 60 mm


d D B C0min max

mm N µm kg –

40 68 15 11 600 160 256 0,19 6008-2Z/VA208

80 18 19 000 160 256 0,37 6208/VA20180 18 19 000 160 256 0,35 6208-2Z/VA20880 18 19 000 160 256 0,35 6208-2Z/VA228

90 23 24 000 160 256 0,63 6308/VA20190 23 24 000 160 256 0,61 6308-2Z/VA208

45 85 19 21 600 180 292 0,41 6209/VA20185 19 21 600 180 292 0,41 6209-2Z/VA20185 19 21 600 180 292 0,39 6209-2Z/VA20885 19 21 600 180 292 0,39 6209-2Z/VA228

100 25 31 500 180 292 0,83 6309/VA201100 25 31 500 180 292 0,79 6309-2Z/VA208

50 80 16 16 000 180 292 0,26 6010-2Z/VA208

90 20 23 200 180 292 0,46 6210/VA20190 20 23 200 180 292 0,46 6210-2Z/VA20190 20 23 200 180 292 0,45 6210-2Z/VA20890 20 23 200 180 292 0,45 6210-2Z/VA228

110 27 38 000 180 292 1,05 6310/VA201110 27 38 000 180 292 1,04 6310-2Z/VA208

55 90 18 21 200 220 360 0,39 6011-2Z/VA208

100 21 29 000 220 360 0,61 6211/VA201100 21 29 000 220 360 0,59 6211-2Z/VA208100 21 29 000 220 360 0,59 6211-2Z/VA228

120 29 45 000 220 360 1,35 6311/VA201120 29 45 000 220 360 1,35 6311-2Z/VA208120 29 45 000 220 360 1,33 6311-2Z/VA228

60 110 22 36 000 220 360 0,78 6212/VA201110 22 36 000 220 360 0,74 6212-2Z/VA208110 22 36 000 220 360 0,74 6212-2Z/VA228

130 31 52 000 220 360 1,70 6312/VA201130 31 52 000 220 360 1,60 6312-2Z/VA208

r

r

r

r12

12

DD 2

B

d d1

3

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mm mm

40 49,3 61,1 1 44,6 63,4 1

52,6 69,8 1,1 46,5 73,5 152,6 69,8 1,1 46,5 73,5 152,6 69,8 1,1 46,5 73,5 1

56,1 77,7 1,5 48 82 1,556,1 77,7 1,5 48 82 1,5

45 57,6 75,2 1,1 51,5 78,5 157,6 75,2 1,1 51,5 78,5 157,6 75,2 1,1 51,5 78,5 157,6 75,2 1,1 51,5 78,5 1

62,1 86,7 1,5 53 92 1,562,1 86,7 1,5 53 92 1,5

50 59,8 72,8 1 54,6 75,4 1

62,5 81,7 1,1 56,5 83,5 162,5 81,7 1,1 56,5 83,5 162,5 81,7 1,1 56,5 83,5 162,5 81,7 1,1 56,5 83,5 1

68,7 95,2 2 59 101 268,7 95,2 2 59 101 2

55 66,3 81,5 1,1 61 84 1,0

69 89,4 1,5 63 92 1,569 89,4 1,5 63 92 1,569 89,4 1,5 63 92 1,5

75,3 104 2 66 109 275,3 104 2 66 109 275,3 104 2 64 111 2

60 75,5 97 1,5 68 102 1,575,5 97 1,5 68 102 1,575,5 97 1,5 68 102 1,5

81,8 113 2,1 71 119 281,8 113 2,1 71 119 2

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2Z/VA228 2Z/VA208 VA201 2Z/VA201

20


Page ............. 3 Page ............. 8 Deep groove ball bearings for extreme temperaturesd 65 – 120 mm


d D B C0min max

mm N µm kg –

65 120 23 40 500 220 360 0,99 6213/VA201120 23 40 500 220 360 0,99 6213-2Z/VA208120 23 40 500 220 360 0,99 6213-2Z/VA228

140 33 60 000 220 360 2,10 6313/VA201140 33 60 000 220 360 2,00 6313-2Z/VA208140 33 60 000 220 360 2,00 6313-2Z/VA228

70 125 24 45 000 260 420 1,05 6214/VA201125 24 45 000 260 420 1,00 6214-2Z/VA208

150 25 68 000 260 420 2,50 6314/VA201150 35 68 000 260 420 2,70 6314-2Z/VA208

75 130 25 49 000 260 420 1,20 6215/VA201130 25 49 000 260 420 1,20 6215-2Z/VA201130 25 49 000 260 420 1,20 6215-2Z/VA208130 25 49 000 260 420 1,20 6215-2Z/VA228

160 37 76 500 260 420 3,00 6315/VA201

80 140 26 55 000 260 420 1,35 6216-2Z/VA208

85 150 28 64 000 300 480 1,80 6217/VA201150 28 64 000 300 480 1,70 6217-2Z/VA208

90 160 30 73 500 300 480 2,15 6218-2Z/VA228

100 150 24 54 000 300 480 1,25 6020-2Z/VA208

180 34 93 000 300 480 3,15 6220/VA201180 34 93 000 300 480 3,15 6220-2Z/VA208180 34 93 000 300 480 3,15 6220-2Z/VA228

110 170 28 73 500 360 560 1,95 6022-2Z/VA208

120 180 28 80 000 360 560 2,05 6024-2Z/VA208

r

r

r

r12

12

DD 2

B

d d1

3

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mm mm

65 83,3 106 1,5 74 111 1,583,3 106 1,5 74 111 1,583,3 106 1,5 74 111 1,5

88,3 122 2,1 76 129 288,3 122 2,1 76 129 288,3 122 2,1 76 129 2

70 87 111 1,5 78 117 1,587 111 1,5 78 117 1,5

94,9 130 2,1 81 139 294,9 130 2,1 81 139 2

75 92 117 1,5 83 122 1,592 117 1,5 83 122 1,592,1 117 1,5 84 121 1,592,1 117 1,5 84 121 1,5

101 139 2,1 86 149 2

80 101 127 2 89 131 2

85 106 135 2 94 141 2106 135 2 94 141 2

90 112 143 2 99 151 2

100 116 138 1,5 107 143 1,5

124 160 2,1 111 169 2125 160 2,1 111 169 2125 160 2,1 111 169 2

110 129 155 2 119 161 2

120 139 165 2 129 171 2

daDa

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22

The SKF group – a worldwide corporation

SKF is an international industrial Groupoperating in some 130 countries and isworld leader in bearings.

The company was founded in 1907following the invention of the self-align-ing ball bearing by Sven Wingquist and,after only a few years, SKF began toexpand all over the world.

Today, SKF has some 45 000 em-ployees and around 80 manufacturingfacilities spread throughout the world.An international sales network includesa large number of sales companies andsome 7 000 distributors and retailers.Worldwide availability of SKF productsis supported by a comprehensive technical advisory service.

The key to success has been a con-sistent emphasis on maintaining thehighest quality of its products and services. Continuous invest-ment in research and

development has also played a vitalrole, resulting in many examples ofepoch-making innovations.

The business of the Group consistsof bearings, seals, special steel and a comprehensive range of other high-tech industrial components. The experi-ence gained in these various fieldsprovides SKF with the essential know-ledge and expertise required in orderto provide the customers with the mostadvanced engineering products andefficient service.

23

The SKF Engineering & Research Centre is situated just outside Utrecht in TheNetherlands. In an area of 17 000 squaremetres (185 000 sq.ft) some 150 scientists,engineers and support staff are engaged inthe further improvement of bearing perform-ance. They are developing technologiesaimed at achieving better materials, betterdesigns, better lubricants and better seals – together leading to an even better under-standing of the operation of a bearing in itsapplication. This is also where the SKF LifeTheory was evolved, enabling the design of bearings which are even more compactand offer even longer operational life.

The SKF Group is the first major bearingmanufacturer to have been granted approvalaccording to ISO 14001, the internationalstandard for environmental managementsystems. The certificate is the most com-prehensive of its kind and covers more than60 SKF production units in 17 countries.

SKF has developed the Channel concept infactories all over the world. This drasticallyreduces the lead time from raw material toend product as well as work in progress and finished goods in stock. The conceptenables faster and smoother informationflow, eliminates bottlenecks and bypassesunnecessary steps in production. TheChannel team members have the know-ledge and commitment needed to share theresponsibility for fulfilling objectives in areassuch as quality, delivery time, productionflow etc.

SKF manufactures ball bearings, roller bearings and plain bearings. The smallestare just a few millimetres (a fraction of aninch) in diameter, the largest several metres.SKF also manufactures bearing and oilseals which prevent dirt from entering and lubricant from leaking out. SKF’s subsidiaries CR and RFT S.p.A. are amongthe world’s largest producers of seals.

® SKF is a registrered trademark of the SKF Group.

© Copyright SKF 2004The contents of this publication are thecopyright of the publisher and may notbe reproduced (even extracts) unlesspermission is granted. Every care hasbeen taken to ensure the accuracy ofthe information contained in this pub-lication but no liability can be accepted for any loss or damage whether direct,indirect or consequential arising out ofthe use of the information containedhere in.

Publication 4402/III E · April 2004

Printed in Sweden on environmentallyfriendly, chlorine-free paper (MultiartSilk) by Tre Punkter Offsettryckeri.

skf deep groove ball bearings for extreme temperatures cut ... · is mandatory, an skf deep groove...

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