The oil of bearing of high speed main shaft

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1 preface in last few years, as the development of cutting tool material and automation technology, in a lot of engineering fields, the rotate speed coming back with the axis spends the main shaft that is bearing with scroll bearing to rise ceaselessly, exceeded scroll bearing example even given limiting value. Current, top rotate speed already achieved the main shaft of machine tool of medium-sized numerical control and machining center 10000r/min left and right sides, and the main shaft rotate speed of FIDIA copying system already achieved 100000r/min. Round grinder is inside achieve enough grinding rate, the emery wheel of grinding alveolus already was as high as 240000r/min. Raised taller requirement to design and be being made of bearing not only, and raised special requirement to the development of lubricant system. Graph the relation scroll bearing between the attrition moment of force of bearing of roller of 1 biserial cylinder, temperature rise and fuel delivery is lubricant the purpose is to reduce bearing interior attrition and wear away, prevent to burn stick, prolong fatigue life, eduction attrition is hot, cooling. Traditional scroll bearing method of lubrication, be like: Oil bath is lubricant law, grease cup is lubricant law, splash lubrication law, loop is lubricant law and oily mist already all cannot satisfy bearing of high speed main shaft lubricant law to be opposite lubricant requirement. Because bearing of high speed main shaft has firm demand to oily viscosity not only,this is, and also having firm demand to fuel delivery. The relation curve between the attrition moment of force that FAG company built bearing of biserial cylinder roller through much test data, temperature rise and fuel delivery. This curve expressed the concern between temperature rise of moment of force of the smallest attrition, lowest and least fuel delivery well, namely to obtain optimal and lubricant result, overmuch or fuel delivery is too little it is harmful. And before 5 kinds of method of lubrication all cannot control fuel delivery well and truly how many, apply to medium, low speed to roll bearing lubricates only, and oily mist is lubricant the system is very difficult also reliable ground supplies oil to measure almost constant and changeless lubricating oil to each bearing, more or less is the oily quantity that makes each attrition are nodded in a kind of fluctuant condition from beginning to end, how many, go against rotate speed of main shaft bearing rise and of life rise. And develop the oil that rise recently - the lube quantity that gas centers lubricant system to control each attrition accurately to nod, reliability is extremely high, can apply in domain of bearing of high speed main shaft consequently. 2 oil - the working principle that gas centralizes lubricant system pursues 2 oil - gas centers lubricant system principle to pursue 1.

Float switch 2.

Gasoline tank 3.

Pump of variable force plunger + alloter 4.

Mixture a powerful person 5.

Nozzle 6.

Pressure switch (air) 　 7.

Pressure dominates a powerful person or family 8.

Compress air to enter the mouth 9.

Directional a powerful person is oily - gas centralizes lubricant system is to develop a kind of place that rise to need oil to measure least new technology recently, method of lubrication of the reason that be called, ensure lubricant efficient sex is reached reduce wear away, apply to the scroll bearing that high speed rotates especially, applicable fetterses at machine of machine tool manufacturing industry, spin the industry such as manufacturing industry. Oily - if pursue,gas centers principle of lubricant system work 2 are shown, at regular intervals (the minim lubricating oil that 1 ～ 60min) exports by ration of alloter of pump of mensurable force plunger (0.

01 ～ 0.

06mL) and compress air conduit to compress air mediumly (pressure is 0.

3 ～ 0.

5MPa, after discharge is 20 ～ 50L/min) mix up, via internal diameter  the nylon canal of 2 ～ 4mm and installation are in the nozzle of bearing vicinity enters bearing inside, stay in friction point point. 3 oil - the technical requirement that gas centralizes lubricant system is oily - gas centralizes lubricant system is after compressing those who have constant pressure air and lube to mix, form small drop of striation oily fluid, enter office of point of bearing interior friction, mix to lube consequently compress air to all have certain technology demand. 3.

When the technology of 1 lube asks to choose lube, should ensure oily film cannot too thick. Its reason depends on: When oil when film is very thin, oily viscosity increases may not to be able to increase attrition moment of force accordingly. So, below same use condition, the referenced viscosity value that should choose to be offerred than example is great 5 ～ the lube of 10 times, have good viscosity and lubricant property in order to ensure. Oil of ISOVG32 ～ ISOVG100 slideway suits very much; Still can choose below burden condition be able to bear or endure the oil that high pressure contains additive. Should avoid to use viscosity to be in the lube under ISOVG22. Taboo contains the lubricating oil of additive of 2 vulcanization molybdenum, because this is planted,the 2 vulcanization molybdenum in lube can stay in place of the aperture inside nozzle, thereby block nozzle; In addition, the gush plating action of 2 vulcanization molybdenum also can increase bearing surface roughness, aggravate wears away. 3.

2 reduce requirement of experiment of airy technology requirement: Bearing type NNU4926; Rotate speed N=2000r/min; Force F=2000N; ℃ of lube viscosity V=32mm/s(t=40) compress air must dry, and filter precision is not more than 3µm, if the condition is permitted, the groovy moisture desiccator that can configure to have automatic catchment function comes out moisture depart. For accurate without by accident deferent lube, internal diameter is 20 ～ 50L/min roughly for total flow of the air in the pipe of F2 ～ 4mm. Air pressure must the photograph of loss of internal pressure power with internal diameter of length of discharge, pipeline, pipeline, bearing matchs. Certain to technical parameter oil - gas centralizes lubricant system and character, changing lubricant cycle and air allow. To overcome the back pressure of bearing interior, the compression that enters bearing interior air must have constant pressure (0.

3 ～ 0.

5MPa) . Generally speaking, bearing entrance is in pressure not to answer under 0.

15 ～ 0.

2MPa. Experimental condition: Bearing type NNU4926; Rotate speed N=2000r/min; Force F=2000N; ℃ of lube viscosity V=32mm/s(t=40) 4 bearing lube measures computation and design of the fashion that offer oil 4.

1 bearing lube measures computation to roll bearing lubricates requires oily amount depends on greatly the element such as type of bearing type, design of the system that offer oil, lube. Give out very hard one suits any situations, have the formula of the simple palpability of extensive applicability. The bearing that has oily fluid to transmit a function automatically (if horn contacts ball bearing) what need oily quantity to be more than the bearing that does not have oily fluid to transmit a function automatically (if biserial is columnar roller bearing) what require oily amount. Become especially speed sex coefficient (N.

When Dm) value is greater, its difference is more apparent (graph 3) . Pass a large number of tests, the cursory consideration formula of fuel delivery Q is as follows: The Q in Q=WdB type -- fuel delivery, w of 　 of Mm3/h 　 　 -- coefficient, 0.

D of 　 of 01mm/h 　 　 -- bearing internal diameter, b of 　 of Mm 　 　 -- bearing width, mm however, actual fuel delivery enlarges 4 ～ on numeric foundation here even 20 times. To achieve optimal and lubricant result, still need how to much come to amend fuel delivery through the experiment. Graph the 4 means that offer oil 4.

The 2 means that offer oil design the bearing that rotates to high speed, send bearing interior lubricating oil for reliable ground, should take the means that offer oil seriously very (wait like position of nozzle form, installation) design. Bearing is lubricant means depends on completely bearing type and configuration means. To only kind bearing character, optimal and lubricant means is from enter bearing interior at the same time. Nozzle aperture should be made the same score together with core, cannot point to cage. Suck an oil when bearing oneself especially when direction decides not easily () of ball bearing of the contact that be like horn, lube must enter bearing interior by afore-mentioned direction. If the condition is permitted, bearing of the reentrance after lube had better pass a tailor-made spray pipe is in-house. Spray pipe length depends on bearing size, the diameter is 0.

5 ～ 1.

0mm. Also allow to send part of bearing outer lane lubricating oil. Below this kind of circumstance, want to notice to looked carefully at lube to whether enter the pressure area that forms between steel ball and outer lane. To biserial bearing character, lube must enter bearing interior from the local gush with Bian Qiping of outer lane raceway, with lubricating adequately to bearing. Upright when bearing external diameter at 150 ～ 280mm, need raises a spray head again. In addition, precipitate to prevent to form oil residue in bearing bottom, need installs vitta of a discharge, its length is more than 5mm. Lubricate to satisfy main shaft of high speed of contemporary machine tool to be opposite systematic requirement, to oil - each parameter that gas centralizes lubricant system are made even farther detailed and accurate research. Because,this is: The element such as configuration of method of lubrication, lubricant quantity and lube type, bearing type, bearing all is opposite bearing rotate speed rises having decision effect. CNC Milling CNC Machining