The Design of Rolling Bearing Mountings
The Design of Rolling Bearing Mountings The Design of Rolling Bearing Mountings
Floating bearingLocating bearing94: Double-shaft hammer crusher133 FAG
95 Ball tube millTube mills are mostly used in the metallurgical, miningand cement industries. The tube mill described isused in an Australian gold mine for grinding auriferousminerals (grain sizes 4...30 mm) into grit by meansof grinding bodies (balls). The grain size of the materialdepends on the number of balls and the quantity ofadded water. The grinding drum, which revolvesaround its horizontal axis, is lined with chilled-castiron plates. Charged with the grinding stock, it is veryheavy.Operating dataDrum: diameter 5,490 mm, length 8,700 mm; inputpower 3,850 kW; speed 13.56 min –1 ; drum mass whenloaded 400 t; maximum radial load per bearing F r =1,962 kN; maximum thrust load F a = 100 kN; bearingdistance 11,680 mm, throughput 250 t/h.The equivalent dynamic loadP = f z · F r + Y · F a = 2 · 1.5 · 1,962 + 4.5 · 100 =3,393 kNWith a dynamic load rating C = 12,900 kN the index ofdynamic stressing:f L = C/P · f n =12,900/3,393 · 1.31 = 4.98 (L h > 100,000 h).The bearings are very safely dimensioned with regardto nominal rating life.The bearings are mounted in split FAG plummerblock housings SZA48/1500HF (locating bearing) andSZA48/1500HL (floating bearing). The outer rings aretightly fitted into shell sleeves (e.g. made of grey-castiron) in the lower housing half. They facilitate compensationof axial length variations. The sliding effectis enhanced by grease injected into the shellsleeve/housing joint.Bearing selectionTrunnion bearingsAs the drum rotates, the bearings have to accommodate,in addition to the heavy weight, constant shocktypeloads caused by the grinding bodies. Both drumtrunnions are supported on spherical roller bearings ofseries 239, 248 or 249. The bearings compensate forstatic and dynamic misalignments that can be causedby misalignments of the bearing seats (large bearingdistance) or drum deflections. In this example, sphericalroller bearings with a tapered bore (K 1:30), FAG248/1500BK30MB are mounted both as the locatingbearing at the drive end and as the floating bearing atthe feed end. The bearings are mounted on the trunnionwith a wedge sleeve.Drive pinion bearingsThe drive pinion is supported on two spherical rollerbearings FAG 23276BK.MB with adapter sleeveFAG H3276HG, in plummer block housings withTaconite-seals FAG SD3276TST.Bearing dimensioningThe dimensioning of the drum bearings is based onhalf the weight of the loaded drum(400/2 · 9.81 = 1,962 kN).The shock loads are taken into account by a shock factorf z = 1.5. The required nominal rating life is100,000 h; this corresponds to an index of dynamicstressing f L = 4.9.Machining tolerancesThe circumferentially loaded inner rings are press-fittedon the trunnion. This is easily achieved by mountingthem hydraulically on wedge sleeves. The radial clearancereduction and the radial clearance of the mountedbearing have to be observed (see table in FAG catalogueWL 41 520, chapter on spherical roller bearings).The trunnions are machined to h9, with a cylindricitytolerance IT5/2 (DIN ISO 1101); the housing boresto H7.Lubrication, sealingGrease lubrication with a lithium soap base grease ofpenetration class 2 with EP additives, e. g. FAG rollingbearing grease Arcanol L186V. Continuous replenishment(approx. 5 g/h per bearing) ensures adequate lubrication.The bearings are sealed by multiple labyrinths. Due tothe extreme ambient conditions, the labyrinths arepreceded by dirt baffle plates and rubbing seals (Vrings).This combination is also referred to as Taconitesealing. The labyrinths are also continuously replenishedwith approx. 5 g/h per labyrinth.FAG 134
- Page 83 and 84: 60 Spade-type rudderDesignThe slewi
- Page 85 and 86: 61-62 Ship shaft bearings and stern
- Page 87 and 88: 63-64 Ship shaft thrust blocksThe t
- Page 89 and 90: 64a: Complete ship shaft thrust blo
- Page 91 and 92: 65 RefinersWood chips from the wood
- Page 93 and 94: 66 Suction rollsSuction rolls are f
- Page 95 and 96: 68 Dryer rollsThe remaining water i
- Page 97 and 98: 69 Guide rollsGuide rolls guide, as
- Page 99 and 100: 70 Calender thermo rollsThe paper p
- Page 101 and 102: 71 Anti-deflection rollsAnti-deflec
- Page 103 and 104: 73 Run wheel of a material ropewayO
- Page 105 and 106: 74 Rope return sheaves of a passeng
- Page 107 and 108: 75 Rope sheave (underground mining)
- Page 109 and 110: 76 Rope sheave of a pulley blockIn
- Page 111 and 112: 77 Crane pillar mounting with a sph
- Page 113 and 114: 79 Roller track assemblyThe radial
- Page 115 and 116: 80 Crane run wheelOperating dataWhe
- Page 117 and 118: 81 Crane hookThe load suspended fro
- Page 119 and 120: 83 Head pulley of a belt conveyorOn
- Page 121 and 122: Internal bearings for the tension/8
- Page 123 and 124: Belt conveyor idlersMany industries
- Page 125 and 126: 87 Bucket wheel shaft of a bucket w
- Page 127 and 128: 89 Drive unit of a finished goods e
- Page 129 and 130: 91 Vibrating road rollerThe vibrati
- Page 131 and 132: 92 Double toggle jaw crusherDouble
- Page 133: 94 Double-shaft hammer crusherDoubl
- Page 137 and 138: 96 Support roller of a rotary kilnR
- Page 139 and 140: Vibrating machinesVibrating screens
- Page 141 and 142: 98 Two-bearing screen with straight
- Page 143 and 144: 99 Four-bearing screenThe vibration
- Page 145 and 146: 101-103 Large capacity convertersCo
- Page 147 and 148: 104Roll bearings of afour-high cold
- Page 149 and 150: Work rolls for the finishing sectio
- Page 151 and 152: 107 Combined reduction and cogging
- Page 153 and 154: 108 Work rolls of a section millThe
- Page 155 and 156: Two-high rolls of a dressing stand1
- Page 157 and 158: 110 Straightening rolls of a rail s
- Page 159 and 160: 111 Disk ploughIn a disk plough the
- Page 161 and 162: 112 Plane sifterSifters are used in
- Page 163 and 164: Printing pressesPrinting quality is
- Page 165 and 166: 114 Blanket cylinder of a sheet-fed
- Page 167 and 168: 116 Axial piston machineCylinder bl
- Page 169 and 170: 117 Axial piston machineOperating d
- Page 171 and 172: 119 Hot gas fanGas temperature 150
- Page 173 and 174: 121 Optical telescopeOperating data
- Page 175 and 176: 122-124 RadiotelescopeFor radioastr
- Page 177 and 178: 123 Azimuth axis (track roller and
- Page 179 and 180: GlossaryAdditivesAdditives are oil-
- Page 181 and 182: GlossaryAxial clearanceThe axial cl
- Page 183 and 184: GlossaryContamination factor VThe c
Floating bearingLocating bearing94: Double-shaft hammer crusher133 FAG