The Design of Rolling Bearing Mountings

46 Axle box roller bearings for the ICE driving unitThe bogie frame is supported by 2 coil springs each onthe bearing housings. The wheelset with the housingsis connected to the bogie by an arm. A setting mechanismenables the mounting of the wheelsets in thebogies without preload. The bearing units are axiallylocated by a cover.Operating dataAxle load: 19,900 kgWeight of unsprung weight: 2,090 kgDiameter of wheel 1,040 mmMaximum speed 250 to 280 km/h.Housing to:Bearing clearanceH7 (for GGG material)J7 (for aluminium alloys).A slight axial clearance is required for ideal running behaviourof the bogies at top speeds. It is between 0.2and 0.5 mm after mounting.Bearing selectionFAG tapered roller bearing units TAROL 150/250 aremounted in the wheelset housings of the series vehicleswith the designation ET 401. The main component ofthese units is a double row tapered roller bearing withthe dimensions: 150 x 250 x 160 mm.Machining tolerancesThe cones carry circumferential load and therefore havea tight fit: journal to p6.Lubrication, sealingThe TAROL 150 is supplied as a complete unit whichis sealed. The sealing system consists of two parallelouter diameter seated lamellar rings and one singleweblabyrinth acting as a pre-seal. The labyrinth isshaped as a seal cap and pressed into the cup.The seal caps are each provided with four dischargeholes through which excess grease escapes. This is particularlyimportant directly after relubrication. O ringsprotect the bearing unit from the penetration of waterin the seating area of the cup.46: Axle box roller bearings of the ICE driving unit67 FAG