# Bearings

The following is a choice matrix. This matrix can only serve as a rough guideline, so that a more qualified selection is required for each specific application. Not only the bearing choice is important for a proper operation, but also a good mounting is essential. The dimensions of shaft-and bearing house surfaces, distance tubes etc. must give sufficient support to the bearings. The rotating parts of the bearing must not come into contact with stationary parts. The correct building dimensions for each bearing can be found in the bearing tables. The table below indicates the correct measurements for the relief grooves. The stress distribution of a shaft with changing diameters is more favourable as the rounding of the transition of diameters is larger. In heavily loaded shafts usually a large rounding is required. The chamfer dimensions in radial direction (r1, r3) and axial direction (r2, r4) in the bearing tables are the prescribed minimum dimensions according to IS0 582-1979, i.e. there are no longer given nominal dimenstions. Appropriate maximum chamfer dimensions, which are important in the calculation of the radius of the distance tube, can be found in the tables under “Limits for chamfer dimensions”.

 Relief grooves Chamfer Dimensions of relief grooves rs min ba ha rc mm inch mm inch mm inch mm inch 11 1,1 1,5 2 2,1 3 4 5 6 7,5 0,039 0,043 0,059 0,079 0,083 0,118 0,157 0,197 0,236 0,295 2 2,4 3,2 4 4 4,7 5,9 7,4 8,6 10 0,079 0,095 0,126 0,157 0,157 0,185 0,232 0,291 0,339 0,394 0,2 0,3 0,4 0,5 0,5 0,5 0,5 0,6 0,6 0,6 0,008 0,012 0,016 0,020 0,020 0,020 0,020 0,024 0,024 0,024 1,3 1,5 2 2,5 2,5 3 4 5 6 7 0,051 0,059 0,079 0,098 0,098 0,118 0,157 0,197 0,236 0,276

The following tables present you all information for a proper mounting of your bearings.

 Bearing type Fits for massive axes in steel and rotating load for the inner ring Fits for bearing houses of steel from of cast iron and stagnant load on the outer ring Shaft diameters Bearing arrangement Bearing house <18 18 <40 40 <100 100 <140 140 <200 200 <280 280 <500 >500 <300 300 <500 >500 Groove ball bearings j5 k5 k5 k6 k6 m6 m6 m6 Fixed bearing J6 J6 H7 One row angular contact ball bearings with clearance arrangement at the outer ring j6 k6 k6 m6 m6 n6 p6 p6 Loose bearing G6 G7 F7 Double row and paired angular contact ball bearings 32A/33A 72BECB73B j5 k5 k5 m5 m5 m5 Thrust bearing J6 J6 H7 33E k5 m5 m5 Fixed bearing J6 J6 H7 Four point ball bearing k5 k5 m5 m5 n6 Fixed bearing J6 J6 H7 One row cylindrical roller bearings N,NU,NJ k5 k5 m5 m5 n6 p6 p6 r6 Axial bearing Ensure 1 mm clearance against rotation Double row spherical roller bearing k5 k5 m5 m5 n6 p6 p6 r6 Fixed bearing J6 J6 H7 Loose bearing G6 G7 F7 Taperd roller bearings with clearance arrangement at the outer ring k6 k6 m6 m6 n6 p6 p6 Thrust bearing J6 J6 H7 Two row and paired ball bearings k5 k5 m5 m5 n6 p6 p6 r6 Fixed bearing J6 J6 H7 Axial ball bearings h6 h6 h6 h6 h6 g6 g6 g6 Axial bearing G7 G7 F7 Spherical roller thrust bearings j6 j6 j6 j6 j6 j6 j6 j6 Axial bearing 1 mm clearance Shape tolerances Allowed roundness Allowed squareness Allowed conicity across the width of the bearing Allowed surface roughness At rotating load IT5/2 IT5 As: Ra = 0,8 At stagnating load IT6/2 IT6 IT6 Huis: Ra = 3,2

Mounting of double-row spherical roller bearings with a conical bore

 Bearing bore d in mm Reduction of radial bearing clearance in mm Axial displacement in mm Smallest end clearance after mounting with starting clearance in mm conicity Conicity 1:12 Conicity 1:30 from up to min max min max min max Normal C3 C4 24 30 40 50 65 80 100 120 140 160 180 200 225 250 280 315 355 400 450 500 560 630 710 800 900 1000 1120 30 40 50 65 80 100 120 140 160 180 200 225 250 280 315 355 400 450 500 560 630 710 800 900 1000 1120 1250 0,015 0,020 0,025 0,030 0,040 0,045 0,050 0,065 0,075 0,080 0,090 0,100 0,110 0,120 0,130 0,150 0,170 0,200 0,210 0,240 0,260 0,300 0,340 0,370 0,410 0,450 0,490 0,020 0,025 0,030 0,040 0,050 0,060 0,070 0,090 0,100 0,110 0,130 0,140 0,150 0,170 0,190 0,210 0,230 0,260 0,280 0,320 0,350 0,400 0,450 0,500 0,550 0,600 0,650 0,3 0,35 0,40 0,45 0,6 0,7 0,75 1,1 1,2 1,3 1,4 1,6 1,7 1,9 2,0 2,4 2,6 3,1 3,3 3,7 4,0 4,6 5,3 5,7 6,3 6,8 7,4 0,35 0,4 0,45 0,6 0,75 0,9 1,1 1,4 1,6 1,7 2,0 2,2 2,4 2,7 3,0 3,3 3,6 4,0 4,4 5,0 5,4 6,2 7,0 7,8 8,5 9,0 9,8 – – – – – 1,7 1,9 2,7 3,0 3,2 3,5 4,0 4,2 4,7 5,0 6,0 6,5 7,7 8,2 9,2 10 11,5 13,3 14,3 15,8 17 18,5 – – – – – 2,2 2,7 3,5 4,0 4,2 5,0 5,5 6,0 6,7 7,5 8,2 9,0 10 11 12,5 13,5 15,5 17,5 19,5 21 23 25 0,015 0,015 0,020 0,025 0,025 0,035 0,050 0,055 0,055 0,060 0,070 0,080 0,090 0,100 0,110 0,120 0,130 0,130 0,160 0,170 0,200 0,210 0,230 0,270 0,300 0,320 0,340 0,020 0,025 0,030 0,035 0,040 0,050 0,065 0,080 0,090 0,100 0,100 0,120 0,130 0,140 0,150 0,170 0,190 0,200 0,230 0,250 0,290 0,310 0,350 0,390 0,430 0,480 0,540 0,035 0,040 0,050 0,055 0,070 0,080 0,100 0,110 0,130 0,150 0,160 0,180 0,200 0,220 0,240 0,260 0,290 0,310 0,350 0,360 0,410 0,450 0,510 0,570 0,640 0,700 0,770

## Axial bearing clearance of a one row angular contact bearings series 72BE and 73 paired in O of X setting

 Bore d in mm Axial clearance in mm CA CB CC from up to min max min max min max – 10 18 30 50 80 120 180 250 10 18 30 50 80 120 180 250 315 4 5 7 9 11 14 17 21 26 12 13 15 17 23 26 29 37 42 14 15 18 22 26 32 35 45 52 22 23 26 30 38 44 47 61 68 22 24 32 40 48 55 62 74 90 30 32 40 48 60 67 74 90 106

## Pre stress of one row angular contact bearings series 72BE and 73 paired in O of X setting

 Bore in mm Pre stress CA CB CC from up to min in μ max in μ max in N min in μ max in μ min in N max in N min in μ max in μ min in N max in N 10 18 30 50 80 120 180 250 18 30 50 80 120 180 250 315 +4 +4 +4 +6 +6 +6 +8 +8 -4 -4 -4 -6 -6 -6 -8 -8 80 120 160 380 410 540 940 1080 -2 -2 -2 -3 -3 -3 -4 -4 -10 -10 -10 -15 -15 -15 -20 -20 30 40 60 140 150 200 330 380 330 480 630 1500 1600 2150 3700 4250 -8 -8 -8 -12 -12 -12 -16 -16 -16 -16 -16 -24 -24 -24 -32 -32 230 340 450 1080 1150 1500 2650 3000 660 970 1280 3050 3250 4300 7500 8600

## Standard clearance of paired bearings one row metric taperd roller bearings

 Bore in mm Axial clearance Serie 320X Serie 302, 322 Serie 313(X) from up to min in μ max in μ min in μ max in μ min in μ max in μ – 30 40 50 65 80 100 120 140 160 180 200 225 250 30 40 50 65 80 100 120 140 160 180 200 225 250 280 80 100 120 140 160 190 220 240 270 310 340 390 440 490 120 140 160 180 200 230 280 300 330 370 400 450 500 550 100 120 140 160 180 210 220 240 270 310 340 390 440 490 140 160 180 200 220 270 280 300 330 370 400 450 500 550 60 70 80 100 110 110 130 160 180 – – – – – 100 110 120 140 170 170 190 220 240 – – – – –

## Axial clearance of cylindrical roller bearings

 Bore Axial serial clearance of bearing d in mm NUP 2 NJ 2 + HJ NUP 3 NJ 3 + HJ NUP 4 NJ 4 + HJ NUP 22 NJ 22 + HJ NUP 23 NJ 23 + HJ min in μ max in μ min in μ max in μ min in μ max in μ min in μ max in μ min in μ max in μ min in μ max in μ min in μ max in μ min in μ max in μ min in μ max in μ min in μ max in μ 15 17 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 120 130 140 150 160 170 180 190 200 220 240 260 280 – 37 37 37 37 47 47 47 47 47 47 47 47 47 47 62 62 62 62 62 62 62 62 62 62 87 87 87 87 87 95 – – – – 140 140 140 140 155 155 155 155 155 155 155 155 155 155 180 180 180 180 180 180 180 180 180 180 230 230 230 230 230 230 – – – 42 42 42 42 42 52 52 52 52 52 52 52 52 52 52 72 72 72 72 72 72 72 72 72 72 102 102 102 102 102 110 110 110 110 165 165 165 165 165 185 185 185 185 185 185 185 185 185 185 215 215 215 215 215 215 215 215 215 215 275 275 275 275 275 290 310 310 310 – 37 37 47 47 47 47 47 47 47 62 62 62 62 62 62 62 62 87 87 87 87 87 87 87 – – – – – – – – – – 140 140 155 155 155 155 155 155 155 180 180 180 180 180 180 180 180 230 230 230 230 230 230 230 – – – – – – – – – 42 42 42 52 52 52 52 52 52 52 72 72 72 72 72 72 72 72 102 102 102 102 102 102 102 110 – – – – – – – – 165 165 165 185 185 185 185 185 185 185 215 215 215 215 215 215 215 215 275 275 275 275 275 275 275 310 – – – – – – – – – – – – – 55 55 55 70 70 70 70 70 70 – – – – – – – – – – – – – – – – – – – – – – – – – 155 155 155 185 185 185 185 185 185 – – – – – – – – – – – – – – – – – – – – – – – – 60 60 60 60 80 80 80 80 80 80 80 110 110 110 110 110 110 110 – – – – – – – – – – – – – – – – 200 200 200 200 235 235 235 235 235 235 235 290 290 290 290 290 290 310 – – – – – – – – – – – – – 37 47 47 47 47 47 47 47 47 62 62 62 62 62 62 62 62 87 87 87 87 87 87 87 – – – – – – – – – – 140 155 155 155 155 155 155 155 155 180 180 180 180 180 180 180 180 230 230 230 230 230 230 230 – – – – – – – – – – 42 52 52 52 52 52 52 52 52 72 72 72 72 72 72 72 72 102 102 102 102 102 102 102 140 140 140 – – – – – – – 165 185 185 185 185 185 185 185 185 215 215 215 215 215 215 215 215 275 275 275 275 275 275 275 375 375 375 – – – – – – – 47 47 47 47 62 62 62 62 62 87 87 87 87 87 87 87 87 120 120 120 120 120 120 120 – – – – – – – – – – 155 155 155 155 180 180 180 180 180 230 230 230 230 230 230 230 230 315 315 315 315 315 315 315 – – – – – – – – – – 52 52 52 52 72 72 72 72 72 102 102 102 102 102 102 102 102 140 140 140 140 140 140 140 140 – – – – – – – – – 183 183 183 183 215 215 215 215 215 275 275 275 275 275 275 275 275 375 375 375 375 375 375 375 375 – — – – – –

## Journal-bearing bushes:

As previously reported, one is in certain cases forced to mount journal-bearing bushes. The following table lists the properties of the most common journal-bearing materials. Sliding speed: v = n.p.d.  in m/s (d in mm – n in 1/min) Surface pressure: p =  in N/mm2 (F in N – d in mm – b in mm)

 ++ : excellent +: good 0: applicable -: not suitable Bronze Powder bronze Bronze with axial split PTFE- Composite POM- Composite Composite with RVS-back PTFE polymide Wound bush Self-lubricating properties – + – ++ + ++ ++ ++ Maintenance free operation – + 0 ++ + ++ ++ ++ Contaminating circumstances + 0 ++ – 0 – – + Corrosion resistance + 0 + 0 0 ++ ++ ++ High temperature + – + ++ 0 + 0 + High load 0 – 0 + ++ + 0 ++ Colliding loads/vibrations + 0 + 0 0 0 – ++ High sliding speeds – ++ 0 + + + 0 – Low friction – + – ++ ++ ++ 0 ++ Less well surface quality axis + – 0 – 0 – 0 0 Small working clearance – 0 0 ++ + + 0 – Less sensitive for tilt + 0 0 – 0 – 0 + Low price level 0 + + ++ ++ – ++ – Temperature range in °C -40…+150 -10….+100 -40….+150 200….+250 -40….+110 -150….+150 -30….+110 -50….+140 Coefficient of friction μ 0,08…0,1550 0,05..0,1010 0,08..0,1540 0,03..0,0880 0,04..0,12120 0,03..0,0880 0,06..0,1540 0,03..0,08140 Admissible surface pressure in N/mm22 –dynamic -static 140 50 120 250 250 300 80 200 Admissible sliding speed in m/s 0,5 0,25….10 1,0 2,0 2,0 1,5 1,0 0,5 Shaft tolerance e7….e8 f7….f8 e7….f8 f6….h7 h7….h8 g6….f7 h8….h9 h7….h8 Housing tolerance H7 H7 H7 H7 H7 H7 H7 H7 Surface hardness of shaft, Ra. in μm 0,8…1,6 0,2….0,8 0,4….0,8 0….0,4 0….0,8 0….0,4 0….0,8 0….0,8 Surface hardness of shaft. in HB 180….400 200….300 150….400 300….600 150….600 300….600 100….300 200….600