Pit & Quarry, February 2011

MOUNTING OF SPHERICAL ROLLER BEARINGS WITH TAPERED BORES Bearings with tapered bores are mounted on tapered shafts or ADAPTERS IGS AND MOUNTING A BEARING USING RADIAL CLEARANCE REDUCTION Example 4HE BEARING TO BE MOUNTED IS A MM BORE X WITH CLEARANCE 1 5SING FEELER GAUGES THE CLEARANCE IN THE BEARING MEASURES v 2 ROM THE h2EDUCTION IN 2ADIAL LEARANCEvCOLUMN IN THE CHART THE REDUCTION IN CLEARANCE IS v TO v 3UBTRACT THESE NUMBERS FROM the measured clearance REDUCTION OF RADIAL CLEARANCE FOR NSK SPHERICAL ROLLER BEARINGS WITH TAPERED BORES Axial displacement values apply only to solid steel shafts or hollow steel shafts where the bore is equal to or less than one half of the outside diameter If the material is other than steel or if thin walled shafting is used please consult NSK 4APER APPLIES TO 3ERIES AND 4APER APPLIES TO 3ERIES AND OR 0E LESS THAN R USE THE lower half of the reduction range For heavier loads or Pe greater THAN R CARBURIZED OR 4 INNER rings should be specified and the upper half of the reduction range can be used BORE SIZE OR MORE DETAILS SEE PAGE OF THE 3 EARING 2EPLACEMENT UIDE For more information please call 188ThinkNSK 18884465675 or visit www thinknsk com 3 Bearing is installed by one of the recommended methods until the clearance in the bearing is within the mounted clearance range For best results mount bearing at the middle of the range The average of these two measurements taken for both rows may be used as the residual internal clearance Measuring Clearance of Large Size Spherical Roller Bearings When a large bearing is mounted on a shaft the outer ring may be deformed into an oval shape by its own weight If the clearance is measured at the top of the deformed bearing the measured value may be smaller than the true value If an incorrect radial internal clearance is obtained in this manner and the values in the table below are used then the actual interference fit may become too small In this case as shown in IG ONE HALF OF THE TOTAL CLEARANCE AT POINTS A B AND C WHICH ARE ON A horizontal line passing through the bearing center and at the highest position OF THE BEARING MAY BE USED AS THE RESIDUAL INTERNAL CLEARANCE Determining Bearing Bore Size OTE 4O OBTAIN BORE SIZE MULTIPLY THE LAST TWO DIGITS OF PART NUMBER BY E G PART X MM BORE 0ART NUMBERS WITH BORE SIZES mm and larger are written with a slash followed by the actual bore size e g The internal clearance of a bearing varies with the axial movement of the taper Check the clearance before mounting the bearing Axially displace the bearing until the radial clearance reduction equals the value calculated on the reverse side Measure radial clearance during mounting with a feeler gauge As SHOWN IN IG THE CLEARANCES FOR both rows of rollers must be measured simultaneously and these two values should be kept roughly the same by adjusting the relative position of the outer and inner rings Fig 1 Mounting with Adapter Fig 2 Mounting with Withdraw Sleeve Fig 3 Measuring Clearance of 3PHERICAL 2OLLER EARING Fig 4 EASURING LEARANCE OF ARGE 3IZE 3PHERICAL 2OLLER EARINGS EASURED LEARANCE v v 2EDUCTION v v OUNTED LEARANCE v v