Catalog: Precision Rolling Bearings | |
| precision rolling bearings page technical data contents 1 ... classification of precision rolling bearings for machine tools q main spindle ... bearings w ball screw support bearings 2 4 2 4 15 5 7 11 14 21 16 20 21 26 22 ... 32 33 37 38 47 40 41 47 53 48 48 50 1 2 bearing selection and shaft housing design q ... bearing selection w bearing accuracy e bearings and rigidity r designing bearing and ... housing 5 3 load rating and life q bearing life w static load rating and allowable ... axial load 16 4 allowable speed 5 bearing arrangements and structures of bearings ... for main spindles qwerqwertyuio bearing arrangement for main spindles bearing ... selection based on bearing arrangement for main spindle adjustable ... preload bearing unit bearing jacket cooling system 22 6 handling of ... | |
| 1 classification of precision rolling bearings for machine tools 1 main spindle ... bearings table .1 types of precision rolling ... bearings for machine tools bearing type standard cross section bearing ... 78c 79 u 5s-79 u 70 u 5s-70 u 72c high-speed 2la-hse9 5s-2la-hse9 bearing bore mm ... contact angle remarks ˇa bearing type code containing a suffix u means ... an ultage series bearing optimized interior structure and resin ... with bore diameter of 10 to 130 mm ˇbearings with prefix 5s have ceramic balls ˇ ... for the interior structure lead to higher speed rigidity and reliability ˇ ... bearings with prefix 5s have ceramic balls ˇ ... small diameter ceramic balls to achieve higher speed and limited heat buildup ˇ ... bearings with prefix 5s have ceramic balls ˇ ... | |
| factor values so operating conditions high rotational accuracy necessary normal ... accuracy deterioration permitted low speed heavy loading etc ball bearings roller ... bearings 2 1 0.5 3 1.5 1 4 allowable speed note when vibration and/or shock loads ... load can be exerted on a main spindle bearing on a machine tool allowing for tool ... stationary when an angular contact ball bearing is subjected to a larger axial load the ... the allowable axial load for each bearing is found in the associated dimensions ... table high bearing speed leads to high temperature rise on the bearing owing ... to frictional heating within the bearing when the temperature of the bearing ... significantly possibly leading to bearing overheating or seizure the factors that ... can affect the maximum allowable bearing speed include 1 bearing type 2 bearing ... | |
| technical data 5 bearing arrangements and structures of bearings ... for main spindles 1 bearing arrangement for main spindles typical ... examples of bearing arrangements for main spindles of ... are summarized in table 5.1 an optimal bearing arrangement must be determined through ... of the main spindle in question maximum speed radial and axial rigidities main ... of lubricant so a main spindle bearing should be selected very carefully table ... 5.1 typical examples of bearing arrangements for main spindles bearing ... arrangement for main spindle bearing type typical applications [type ... tapered roller bearing tapered roller bearing double-row cylindrical roller bearing ... [type double-row cylindrical roller bearing double-direction angular contract ... thrust ball bearing double-row cylindrical roller bearing ... | |
| technical data bearing arrangement for main spindle bearing ... [type single-row cylindrical roller bearing high-speed duplex angular contact ball ... bearing for axial load single-row cylindrical ... roller bearing typical applications cnc turning ... machining center typical lubrication ˇgrease lubrication ˇair-oil lubrication built- ... in motor-driven configuration note high-speed variant of type [type duplex angular ... contact ball bearing dtbt arrangement single-row angular ... contact roller bearing w ball slide machining center | |
| technical data 2 bearing selection based on bearing arrangement ... for main spindle an optimal bearing product that best suits the application ... is selected by referring to the bearing selection table in table 5.2 which ... contains the possible bearing arrangements for main spindles ˇ ... free side and fixed side ˇselect the bearing arrangement type i to xii on the free ... or fixed side table 5.2 bearing selection table fix side free side ... lubrication bearing specifications system applicable ... 2la-hse0/5s-2la-hse0 ˇselect a set of bearing specifications applicable to the ... system suitable for the selected bearing specifications ˇselect a product group ... considerations for selection procedure bearing selection 1 high-speed performance ... general high low contact angle 15° 20° 25° 30° ... | |
| technical data 6 handling of bearings 1 cleaning and filling with grease to ... achieve maximum speed and limited temperature rise with a ... precision rolling bearing it is vital to handle the bearing ... correctly the handling of bearings involves cleaning drying filling with ... grease if necessary and the running-in ... precautions and instructions a sealed bearing contains prefilled grease do not clean ... rinse and dry this type of bearing only wipe away rustpreventive oil with ... a clean cloth before assembling the bearing of grease after drying be sure to ... immediately fill the bearing with grease drying can be performed by blowing hot ... air onto the bearing or placing the bearing in a chamber at constant temperature ... the cleanliness of the air filling with grease the procedures for greasing ball and ... | |
| technical data 7 lubrication of bearings in a bearing lubrication forms a thin ... of heat due to friction 3 longer bearing life 4 rust prevention 5 protection ... between oil volume friction loss and bearing temperature the lubrication methods ... available for bearings in a machine tool include grease ... features of various lubrication methods high high table 7.2 evaluation of various ... lubrication method criterion handling grease lubrication oil mist lubrication air- ... table 7.1 oil volume friction loss and bearing temperature fig 7.1 zone features ... possibly leading to abnormal wear and bearing seizure a uniform uninterrupted oil ... film is formed friction is minimal and bearing temperature is kept low grease ... rolling elements [mm multiplied by speed [min-1 a further increase in oil volume ... | |
| of super 2 new material and new surface high-speed precision bearings for machine tool ... developing the ultage series of super-high-speed precision bearings this new line of ... bearings demonstrates excellent performance ... the use of special materials special grease and seals on both sides ultage is a ... realize the ultimate level of precision bearing design modification technology the ... ultage super high-speed precision bearing series for machine tool main spindles ... /min turbine vg56 oil bath from low-speed heavy-duty machining to high-speed ... concept our ideal is to offer a super high-speed precision bearing that offers excellent ... material no flaking design the internal bearing design has been optimized to cope with ... conditions in order to realize high speed and high rigidity limited temperature ... | |
| in fig 8.5 test conditions test bearing preload lubrication outer casing ... reducing air and oil consumptions and a grease-lubricated sealed design that reduces ... environmental impact by employing a grease lubrication system that is capable of ... higherspeed operation basic bearing number hse020 100 150 24 2 rows 2.5 kn ... constant pressure preloading grease none required functions for the main ... spindle bearing speed rigidity durability precision eco- ... steel balls ceramic balls 15000 shaft speed min-1 0 0.5 1 1.5 1.9 for main spindles ... type dmn valu 106 the ultage series bearings employ well-proven ceramic balls to ... contributes to energy savings grease lubrication high-speed bns llb type ... sealed sealed the introduction of a grease lubrication system that is capable of ... | |
| technical data grease-lubricated sealed angular contact ball bearings 1 ... of handling ultage angular contact ball bearings with seals are grease-prefilled ... bearings no grease filling is necessary you need only wipe ... which also makes it easy to orient the bearings in combinations table 8.1 table 8.1 ... bearing combinations and seal colors db set ... series sealed angular contact ball bearing makes possible high-speed operation ... with grease lubrication thanks to optimized ... internal design grease lubrication with minimal mist splash ... reduction fig 8.6 air-oil lubrication grease lubrication simplifies the main spindle ... system air-oil lubrication to grease lubrication 51 ... | |
| ntn main spindle bearings main spindle bearings 9 angular contact ball bearings for ... loads contents 9 angular contact ball bearings for radial loads 56 213 q features of ... types 56 w standard cage design 58 e bearing designations 58 r bearing accuracy 60 t ... preload of duplex angular contact ball bearings 62 y recommended fit for angular ... contact ball bearings 68 u duplex angular contact ball ... bearings 68 i duplex arrangement codes of duplex ... angular contact ball bearings 69 o flush grinding and universal ... matching 69 !0 angular contact ball bearings with ceramic balls 70 !1 operating life ... of bearings with ceramic balls 71 !2 recommended ... 72 !3 standard angular contact ball bearings 79u and 70u types 73 !4 high-speed ... angular contact ball bearings hse type 74 !5 super high-speed angular ... | |
| ntn main spindle bearings eco-friendly air-oil lubricated angular ... ball bearings hsl and hsfl types for eco-friendly air ... -oil lubricated angular contact ball bearings hsl and hsfl types the angle of the ... in addition these angular contact ball bearings are dedicated to airoil lubrication by ... nozzle they accommodate the same high speed as hse and hsf types while being more ... air and oil the accuracies of these bearing types are jis class 5 or better for the ... designed eco-friendly nozzle sealed bearings standard grease-lubricated sealed ... angular contact ball bearings 79llb/70llb types the standard grease- ... lubricated sealed angular contact ball bearings are available in 79 and 70 series non- ... are mounted on both sides and special grease is used as a result these bearings ... | |
| ntn main spindle bearings table 9.15 high-speed grease-lubricated sealed angular ... contact ball bearings bns9 series nominal bore diameter d 50 ... 520 530 550 655 665 685 970 table 9.16 high-speed grease-lubricated sealed angular ... contact ball bearings bns0 series nominal bore diameter d 45 ... 030 1 040 1 220 1 240 1 270 table 9.17 high-speed sealed angular contact ball bearings ... diameter d contact angle 15° table 9.18 high-speed sealed angular contact ball bearings ... diameter d contact angle 15° table 9.19 high-speed sealed angular contact ball bearings ... | |
| ntn main spindle bearings !3 standard angular contact ball ... bearings 79u and 70u types ultage 79u and 70u ... series bearings were developed from standard angular ... contact ball bearings 79 and 70 optimized internal design ... and adoption of a new resin cage allows high-speed operation and ensures high rigidity ... high-speed operation optimized internal design and ... operation at dmn value 950 103 with grease lubrication test conditions test ... bearing shaft speed preload after assembled grease ... 1 optimized internal design enables high-speed operation and high rigidity 2 a new ... resin cage enables improvement in grease retention for grease lubrication and ... of oil for air-oil lubrication 3 bearings are available with either steel or ... jacket cooling w/o jacket cooling 10 5 bearing specifications air-oil 0 5000 10000 ... | |
| ntn main spindle bearings !4 high-speed angular contact ball bearings hse type ... internal design this type achieves high speed high rigidity and high ... rise the 5s-hse type features high speed and limited temperature increase even ... it maintains stable performance at high speeds fig 9.24 test condition test ... bearing shaft speed lubrication oil consumption air ... 2 optimized internal design enables high-speed operation and high rigidity 3 bearings ... 1000 n 0 5000 10000 15000 20000 shaft speed min-1 0 0.5 1.0 1.5 dmn value 106 2.0 2 ... .5 bearing specification air oil fig 9.24 ... main spindle rigidity when built into a high-speed main spindle the preload of the 5s-hse ... standard type is maintained allowing high rigidity 1.9 times greater than a ... | |
| ntn main spindle bearings !7 grease-lubricated sealed standard angular contact ball ... bearings 79llb and 70llb 5s-79llb and 5s-70llb ... types the 79llb and 70llb types are grease-lubricated eco-friendly bearings that can achieve ... stable high-speed operation with limited temperature rise ... with shaft diameters less than 50 mm bearing specifications features 1 internal ... design is optimized for high-speed operation and limited temperature rise ... 2 longer grease life due to adoption of special grease ... and non-contact seals for grease retention 3 contact angles of 15° and ... for front black and back orange sides bearing configuration can be easily identified ... and 70llb types can reliably run at a higher speed with grease lubrication the ... grease lubricating system is virtually free ... | |
| ntn main spindle bearings !8 grease-lubricated sealed angular contact ball bearings ... and internal structure bns llb type bearings have excellent performance at higher ... speeds this helps to reduce pollution and cost ... bearing specification features 1 adoption of ... 2 optimized internal design enables high-speed operation and high rigidity 3 available ... steel or ceramic balls 4 adoption of grease pockets special grease and non-contact ... seals improves service life of the grease fig 9.37 bns llb type simplified main ... spindle configuration bns llb type bearings can reliably operate at a higher speed ... with grease lubrication the grease lubrication system is virtually free ... capable of replacing air-oil lubricated bearings up to dmn value of 1,400,000 air-oil ... | |
| ntn main spindle bearings permissible speed range dmn value 106 0 0.2 0.4 0.6 0.8 1 ... ° 15° 20° 25° 15° 20° notes permissible speed of each bearing dmn value varies ... of the machine on which the bearing is used motor drive system cooling ... system and construction around the bearing consider the optimal choice referring ... increase 5s-2la-bns llb type bearings exhibit stable temperature increase up ... ,000 fig 9.39 20 test conditions test bearing shaft speed outer casing cooling 5s-2la ... 5 0 0 2000 4000 6000 8000 10000 12000 speed min-1 0 0.5 1.0 1.5 dmn value 106 fig 9 ... .39 high-speed test results durability test as a ... result of optimized design such as grease reservoir and special grease 5s-2la-bns ... llb type bearing have successfully achieved continuous ... bns type 20000 h or longer test bearing shaft speed preload outer casing ... | |
| main spindle bearings high-speed angular contact ball bearings steel ... load capacity kn kgf factor limiting speed min-1 grease oil lubrication ... | |
| main spindle bearings high-speed angular contact ball bearings steel ... axial load capacity kn kgf limiting speed min-1 grease oil lubrication ... | |
| main spindle bearings high-speed angular contact ball bearings steel ... axial load capacity kn kgf limiting speed min-1 grease oil lubrication ... | |
| main spindle bearings high-speed angular contact ball bearings steel ... load capacity kn kgf factor limiting speed min-1 grease oil lubrication ... | |
| main spindle bearings high-speed angular contact ball bearings steel ... axial load capacity kn kgf limiting speed min-1 grease oil lubrication ... | |
| main spindle bearings high-speed angular contact ball bearings steel ... axial load capacity kn kgf limiting speed min-1 grease oil lubrication ... | |
| main spindle bearings high-speed angular contact ball bearings ceramic ... load capacity kn kgf factor limiting speed min-1 grease oil lubrication ... | |
| main spindle bearings high-speed angular contact ball bearings ceramic ... axial load capacity kn kgf limiting speed min-1 grease oil lubrication ... | |
| main spindle bearings high-speed angular contact ball bearings ceramic ... axial load capacity kn kgf limiting speed min-1 grease oil lubrication ... | |
| main spindle bearings high-speed angular contact ball bearings ceramic ... load capacity kn kgf factor limiting speed min-1 grease oil lubrication ... | |
| main spindle bearings high-speed angular contact ball bearings ceramic ... axial load capacity kn kgf limiting speed min-1 grease oil lubrication ... | |
| main spindle bearings high-speed angular contact ball bearings ceramic ... axial load capacity kn kgf limiting speed min-1 grease oil lubrication ... | |
| main spindle bearings sealed high-speed angular contact ball bearings steel ... 11.2 11.3 11.2 11.3 11.3 11.2 limiting speed min-1 grease lubrication 21 800 19 700 ... | |
| main spindle bearings sealed high-speed angular contact ball bearings steel ... axial load capacity kn kgf limiting speed min-1 grease lubrication 23 100 20 800 ... | |
| main spindle bearings sealed high-speed angular contact ball bearings steel ... axial load capacity kn kgf limiting speed min-1 grease lubrication 20 500 18 500 ... | |
| main spindle bearings sealed high-speed angular contact ball bearings steel ... 10.9 10.9 10.9 10.9 11.0 11.0 limiting speed min-1 grease lubrication 22 200 20 500 ... | |
| main spindle bearings sealed high-speed angular contact ball bearings steel ... axial load capacity kn kgf limiting speed min-1 grease lubrication 23 500 21 600 ... | |
| main spindle bearings sealed high-speed angular contact ball bearings steel ... axial load capacity kn kgf limiting speed min-1 grease lubrication 20 800 19 200 ... | |
| main spindle bearings sealed high-speed angular contact ball bearings ceramic ... .8 7.7 7.8 7.8 7.8 7.8 7.8 7.7 limiting speed min-1 grease lubrication 25 600 23 100 ... | |
| main spindle bearings sealed high-speed angular contact ball bearings ceramic ... axial load capacity kn kgf limiting speed min-1 grease lubrication 28 200 25 500 ... | |
| main spindle bearings sealed high-speed angular contact ball bearings ceramic ... axial load capacity kn kgf limiting speed min-1 grease lubrication 25 600 23 200 ... | |
| main spindle bearings sealed high-speed angular contact ball bearings ceramic ... .5 7.5 7.5 7.5 7.6 7.6 7.6 7.6 limiting speed min-1 grease lubrication 26 000 24 000 ... | |
| main spindle bearings sealed high-speed angular contact ball bearings ceramic ... axial load capacity kn kgf limiting speed min-1 grease lubrication 28 700 26 500 ... | |
| main spindle bearings sealed high-speed angular contact ball bearings ceramic ... axial load capacity kn kgf limiting speed min-1 grease lubrication 26 100 24 100 ... | |
| ntn main spindle bearings 10 cylindrical roller bearings in a ... cylindrical roller bearing the rollers and raceways are in linear ... contact consequently this type of bearing can support a larger radial load than a ... point-contact ball bearing also its structure is suitable for high ... -speed operation a cylindrical roller bearing used for the main spindle of a machine ... 2 single-row cylindrical roller bearings single-row cylindrical roller bearings ... are available in two types high-speed n10hs type and ultra highspeed n10hsrt6 ... type the n10hs type bearings have high-strength machined brass cages while the n10hsr ... type bearings have special molded resin cages which ... can be used for both grease lubrication and air-oil lubrication the ... n10hslt6 type is a variation from the high-speed n10hsrt6 type bearing and can be used ... | |
| ntn main spindle bearings 9 ultra high speed double row cylindrical roller bearings ... nn30hsrt6 type nn30hsrt6 ultra high speed double row cylindrical roller bearings ... have higher operating speed with the same level of rigidity and ... capacity as the conventional series bearing design features 1 optimized internal ... design to realize high speed and low temperature rise 2 molded peek ... cage is used for high speed under grease air-oil lubrication and grease life ... fig 10.4 nn30hsrt6 type permissible speed range dmn value 106 0 0.2 0.4 0.6 0.8 1 ... .0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 grease lubrication air-oil lubrication ... nn30hsrt6 notes permissible speed of each bearing dmn value varies ... of the machine for which the bearing is used motor drive system cooling ... | |
| ntn main spindle bearings high speed test dmn value of 1.0 million under ... grease lubrication and 1.75 million under air- ... design fig 10.5 10.6 test conditions bearing speed mounted radial clearance ... lubrication grease type jacket cooling nn3020hsrt6k ... nn3020hsk 100 150 37 8000 min-1 5 m grease lubrication mp-1 yes test conditions ... bearing speed mounted radial clearance lubrication ... 2000 4000 6000 8000 0 5000 10000 15000 speed min -1 speed min-1 0 0.25 0.5 0.75 1.0 ... fig 10.5 comparison of temperature rise grease fig 10.6 comparison of temperature rise ... air oil grease life over 8500 hours continuous ... operation under grease lubrication is realized by the improved ... nn3020hsk 100 150 37 8000 min-1 speed 5 m mounted radial clearance grease ... | |
| ntn main spindle bearings !0 ultra high-speed single row cylindrical roller bearings ... type n10hsrt6 type cylindrical roller bearings have been designed for high-speed ... operation bearing specification features 1 optimized ... internal design allows high speed operation and limits temperature ... 2 special resin cage is suitable for high-speed operation fig 10.3 n10hsrt6 type ... permissible speed range dmn value 106 0 0.2 0.4 0.6 0.8 1 ... .0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 grease lubrication air-oil lubrication ... n10hsrt6 notes permissible speed of each bearing dmn value varies ... of the machine for which the bearing is used motor drive system cooling ... system and construction around the bearing consider the optimal choice referring ... internal structure the n10hsr type bearings can reliably run at a higher speed with ... | |
| ntn main spindle bearings high-speed operation test with grease lubrication ... design the n10hsr type is capable of high-speed operation with dmn value of 1.15 ... million [grease lubrication or 2.3 million [air-oil ... .6 10.7 10.8 10.9 test conditions test bearing shaft speed mounted radial clearance ... n1011hs 55 90 18 16000 min-1 0 m grease no test conditions test bearing shaft ... speed mounted radial clearance lubrication ... n1011hs 55 90 18 16000 min-1 0 m grease yes 20 10 temperature increase of outer ... 4000 6000 8000 10000 12000 14000 16000 speed min 0 0.5 speed min-1 1.0 0 0.5 1.0 dmn ... value 106 dmn value 106 fig 10.6 high-speed test results grease lubrication without ... outer case cooling fig 10.7 high-speed test results grease lubrication with ... | |
| main spindle bearings high speed single row cylindrical roller bearings ... 4 950 5 450 6 700 7 050 8 400 limiting speeds min-1 grease oil lubrication ... 61 67.5 72.5 81 86.1 91 100 105 113 1 a bearing number with suffix k indicates a ... tapered-bore bearing taper ratio 1/12 2 minimum allowable ... | |
| main spindle bearings high speed single row cylindrical roller bearings ... 22 400 24 400 27 800 31 500 limiting speeds min-1 grease oil lubrication ... 132 137 146 155 165 182 192 206 219 1 a bearing number with suffix k indicates a ... tapered-bore bearing taper ratio 1/12 2 minimum allowable ... | |
| main spindle bearings ultra high-speed single row cylindrical roller bearings ... 3 250 3 850 5 100 6 550 7 200 limiting speeds min-1 grease oil lubrication ... | |
| main spindle bearings eco-friendly ultra high-speed single ... row cylindrical roller bearings ultage series air-oil lubrication only ... 3 250 3 850 5 100 6 550 7 200 limiting speeds min-1 grease lubrication 30 900 28 900 ... | |
| ntn main spindle bearings 11 angular contact ball bearings for ... types ntn provides a range of thrust bearings for the main spindles this includes ... 5629 and 5620 series for high axial rigidity contact angle 60° and ... hta ua series high-speed duplex angular contact ball bearings ... design contact angle 40° 30° these bearings are used in conjunction with nn30 nn49 ... series double-row cylindrical roller bearings matched bearings must have the same ... 11.1 types of angular contact ball bearings for axial loads 5629 and 5620 series ... hta0u a db hta9u a db series bearing type initial contact angle cage ... material 60 high-strength machined brass cage these series can ... is enhanced the structure of these bearings limits them to grease-lubricated ... 40 30 molded resin machined phenolic high-strength machined copper alloy cage these duplex ... | |
| ntn main spindle bearings 7 shaft and housing fits fits given in ... recommended for angular contact ball bearings for axial loads to maintain high ... is essential the fit of the housing and bearing should be same as that for cylindrical ... roller bearings since an angular contact ball bearing ... used together with a cylindrical roller bearing checking concentricity of outside ... diameter of outer ring after bearing controlling concentricity of outer ring ... shown in fig 11.1 and 6 handling of bearings 2 mounting in the technical data ... note 1 target the median value 2 for high-speed applications where dmn value exceeds 0. ... specifications angular contact ball bearings for axial loads are usually used with ... grease lubrication or air-oil lubrication ... lubrication methods are described below grease lubrication air-oil lubrication ˇ ... | |
| ntn main spindle bearings 9 angular contact ball bearings for ... u type hta u type angular contact ball bearing has a higher limiting speed with the ... as the conventional hta series bearings design features 1 optimized internal ... the temperature rise especially at high speed range 2 improved molded nylon ... design where the ball contacts to have higher lubrication performance under grease or ... fig 11.2 hta u type permissible speed range dmn value 106 0 0.2 0.4 0.6 0.8 1 ... u hta0 u 40° 30° 40° 30° 30° 40° 30° grease lubrication air-oil lubrication 40° 5s- ... hta0 u notes permissible speed of each bearing dmn value varies depending on the ... of the machine for which the bearing is used motor drive system cooling ... system and construction around the bearing consider the optimal choice referring ... | |
| ntn main spindle bearings high speed test dmn value of 1.0 million under ... grease lubrication and 1.25 million under air- ... design fig.11.5 11.8 test condition bearing :30° hta020uadb hta020adb 100 150 ... 8000 min-1 880 n grease mp-1 w w/o test condition bearing 22.5 ... 2 rows speed mounted preload lubrication oil air ... interval 5 min 40 nl/min w w/o 2 rows speed mounted preload lubrication grease type ... 4000 6000 -1 8000 2500 5000 7500 10000 speed 0 0.25 0.5 min speed 0.75 1.0 0 0.25 0. ... fig 11.5 comparison of temperature rise grease 30° fig 11.6 comparison of temperature ... rise air-oil 30° test condition bearing :40° hta020udb hta020db 100 150 6000 ... min-1 1470 n grease mp-1 w w/o test condition bearing 22.5 ... 2 rows speed mounted preload lubrication oil air ... | |
