SNR - Industry - vtl.rs

1 SNR - IndustryHigh-Precision Bearingsfor Machine Tool SpindlesTC 02 USAbCr ation Annecy - Non contractual document SNR Copyright International 02/03 Printed in France EuropeFRANCE - EUROPESNR Paris40, rue Jean 49T l. 01 40 93 66 0092174 Vanves CedexFax. 01 40 93 66 10 SNR Logistique9, avenue L on HarmelT l. 01 46 11 66 5092160 AntonyFax. 01 46 11 66 66 DEUTSCHLANDSNR W LZLAGER D sseldorfWahlerstra e 6 Tel. (0211) 6 58 06-040437 D sseldorfFax. (0211) 6 58 88 86 Postfach 33 04 1033719 (0521) 9 24 00-033701 BielefeldFax. (0521) 9 24 00 90 Postfach 17 01 4570597 StuttgartTr nkestra e 7 Tel.

2 (0711) 9 00 64-070574 StuttgartFax. (0711) 9 00 64 99 Postfach 70 04 16 SNR Bordeaux1, rue du Golf - 173T l. 05 56 34 69 8033708 Merignac CedexFax. 05 56 34 69 81 SNR LyonLe Florentin - 71, cheminT l. 04 78 66 68 00 Europe*du Moulin Carron - 8 Fax. 04 78 66 68 2069570 DardillySNR Nancy3, all e For t de la ReineT l. 03 83 44 64 00 Europe*Parc technologique BraboisFax. 03 83 44 02 3154500 Vand uvreITALIASNR ItaliaMilanoVia Keplero, 5 Tel. (02) 33 55 2120019 SettimoFax (02) 33 50 06 56 Milanese (MI)BolognaVia , 2/2 Tel. (051) 36 79 4640128 Bologna(051) 36 29 78 Fax (051) 36 85 38 ESPA A - PORTUGALSNR Rodamientos Ib rica Llanos de Jerez, 22T l.

3 91 671 89 13 Pol gono IndustrialFax. 91 673 65 4828820 Coslada*EUROPE(Subsidiaries excepted)SNR Nancy - Europe : Benelux - Suisse - Autriche - Lyon - Europe : Other Countries Fax. 04 78 66 68 21 USASNR Bearings K Highlands PkwyTel. (770) 435-2818 Smyrna, 30082(800) 232-1717 Fax. (800) 742-5215 AMERICA LATINASNR ArgentinaBuenos AiresViamonte 1145 - Piso 11 Tel. (54) 11-4 372-12721053 Buenos AiresFax. (54) 11-4 372-0088 SNR Intermondial (Overseas)Annecy18, rue du Val-VertT l.(33) 4 50 65 96 00/01/0274600 SeynodFax.(33) 4 50 65 96 15 FranceMAROCSNR Maroce-mail : Casablanca17, rue BuzancyT l. (212) 02 2 241 530 Belv d reFax.

4 (212) 02 2 241 532 Casablanca 20300(212) 02 2 241 542Am riques / AmericasAutres pays / Other countriesSi ge social : Rue des Usines - 74 000 Annecy - FRANCERCS Annecy B 325821072 - Code NAF 291 Outil Couv QUADRI+4 14/01/04 15:09 Page 132 SNR High Precision is partner to the majoraeronautical and space programs: Ariane 5, Airbus,Boeing, experience and knowledge that SNR hasacquired in the field of extreme operating conditionscontribute to the performance and high reliability of company s total quality approach is recognized bynumerous certifications: manufacturer approvals, ISO9001, AQAP110, quality methods and tools ensure total controlover the production process based on the StatisticalProcess Control and TPM concepts.

5 Productionresource management is certified MRP class industrial resources and manufacturing processesmeet the very stringent demands of our customers: Production machines capable of achieving ISO 2precision Heat treatment in computer-controlled ovens. Assembly in controlled environment or class 100clean has acquired considerable know-how in themachine tool market through its partnerships withnumerous world-renowned manufacturers and withits own experience as a manufacturer and user ofhigh-precision spindle resources SNR High Precision devotes toResearch and Development make it possible to modelthe operation of the bearing and verify its design bytests.

6 Powerful computation resources to take the bearingstresses into account, Optimum choice of materials, heat treatments andsurface treatments to suit the in equipment and personnel trainingguarantee product quality: Metrology department with sophisticatedmeasuring equipment in compliance with the FrenchBureau of Standards (BNM). Non-destructive testing performed by certifiedtechnicians. Computer controlled data loggers at all HIGH PRECISIONM achine Outil 2 17 14/01/04 15:28 Page 25 ContentsSNR, machine tool spindle bearings Presentation7 The SNR bearing versions8 Technology of angular-contact ball bearings11 Design definition of machine tool spindle bearings14 Preliminary dimensioning 14 Calculation software - simulation16 Simplified calculation method18 General spindle design19 Assembly examples20 SNR ceramic ball bearings22 Identification of bearings24 Marking and Packaging26 Tables of dimensions28 Tables of preloads and rigidity34 Bearing tolerances and precision classes38 Bearing contact surface and seating tolerances40 Sealing43 Lubrication44 Recommended fitting practices46 Technical assistance.

7 Failure analysis48 Machine Outil 2 17 14/01/04 15:28 Page 47 SNR, machine tool spindle bearingsPresentationMachine toolsare constantly evolving to give better productivity and quality SPINDLE is one of the vital components that helps attain these objectives; it must satisfy severalrequirements: high speed of rotation low heat generation good rigidity high precision of rotation long service lifeThe use of high-precision angular-contact ball bearings in spindles has been found to be the best technologicalmeans of achieving the desired performance SNR bearing: its performanceReduced machining time Higher speed Optimum capacityLowermaintenance costs Reliability Long service life Controlof quality Reduced heating Guaranteed preload precision High precision of rotation RigidityMachine Outil 2 17 14/01/04 15.

8 30 Page 698 SNR bearing versionsBasic characteristics of angular-contact bearing Rings and balls in very high quality 52100 vacuum-degassed steel Two angles of contact: 15 and 25 Phenolic resin cage centered on the outer ring Three preload grades ISO 4 (ABEC 7) precision. Possibility of providing ISO 2 (ABEC 9) precisionImportant : The majority of SNR ISO 4 precision bearings achieve ISO 2 (ABEC 9) run-out precision. SNR achieves a highly accurate control of the offset between the outer ring and the inner ring. This non-standard characteristic determines the preload value, which has a strong influence on the rigidity and hence thebehavior of a series and version codesSeriesVersion code719V70V72G1 The reasons behind the performanceDimensions seriesG1 version bearingsThe G1version has been specially developed to meet the specifications of the 72 series, which is typicallydesigned to withstand predominantly high axial loads.

9 Hybrid bearingsBearing performance can be substantially improved by using ceramic balls instead of steel characteristics of SNR hybrid bearings are given on page version bearingsThe 719 and 70series bearings are the best suited to high rotational speeds. Numerous computer simulationsbacked up by tests in both our research center and in industrial situations, have enabled us to optimize these twoseries to obtain the best performance: Speed Capacity Rigidity PrecisionThis research led to the production of the Vversion series by bearings are characterized by an internal geometry which provides: improved dynamic behavior reduced friction limited contact pressure enhanced lubrication and cooling71970727270719 Note: a given outside diameter does notalways exist in all three series Comparison of sections for a given boreReduced shoulderCage.

10 Thickness reduced,lead-in chamferReduced shoulderAccurate ring offset controlOptimized raceway curvatureDimensional precisionBoreOutsidediameterComparison of sections for a given outside diameterFunctional precisionLarge number of ballsV versionMachine Outil 2 17 14/01/04 15:30 Page 8 Characteristics of a preloaded bearing arrangementUniversal or matched set bearing arrangementsExamples:These arrangements can be made with universal bearings or sets matched by us at the factory. See characteristics of the different versions on page preload is an important characteristic of the bearing arrangement. It has a direct influence on the permissiblelevels of load and speed.