Split radial plain bearings, mainly used in overload on medium to large machines, such as metallurgical and mining machinery, large generators, ball Mills, piston compressors and large fans. Its materials mainly for Babbitt, is copper-base bearing alloys under limited circumstances (such as rotary kilns, etc). At the time of Assembly, General scrape approach to meet the accuracy requirements, guarantee its performance. Therefore, scraping quality equipment is essential to the operation. Scraping the poor quality of the cut, while the unit is in test would be easily within a very short period of time is bearing by the local viscosity loss and reaches most of the viscosity loss until the shaft is killed by adhesion, bearing damage cannot be used. So when you scrape bearing technical experienced fitter's operation.
Details below a section of sliding bearing (axle Bush) Assembly required and scraping method of rotor-bearing of the cut.
1, Bush and w and w-Cap contact request
(1) the bearing Bush. Stress bearing contact area of the tile back and tile should be greater than 70%, and should be evenly distributed.
(2) mechanical cover of Bush and Bush does not contact area should be greater than 60%, and should be evenly distributed.
(3) do not meet the above requirements, tile and tile cover should be the baseline, using the method of coloring, coated with red lead powder to check exposure, with a fine file or grinding stone to repair the tiles back Institute, until such time as to meet the requirement. Contact pattern achieved per 25mm2 3~4.
(4) when Bush and w, w cover Assembly, fixed bearing retainer pin (or screw) tip is buried in 2~3mm bearing the body, two and a half tile joints gaskets should be the same as tile aperture shape, the width should be less than 1mm inside the bearing, gaskets should be smooth edges Thorn, w gasket thickness should be consistent on both ends. Tiles, tiles cover the force acting on connecting bolts should be tightened evenly. All parts should be thoroughly cleaned.
2, several major elements of the Bush scraping surfaces the use of performance requirements
(1) oil lines and oil tank with
A, half-open-type sliding bearing, are strong damping, oil is generally open on without stress on the tile (tile on smaller). Section is the semicircular arc along w 180 ° within the week on distribution, which are made by mechanical. Oil bath w central location the oil holes in the middle position and communicate, connections at both ends w oil tank with, due to the tile gaps exist on, lubricating oil on the tile surface and very easy access to on-axis, whose main role is to inject lubricating oil flow inside the bearing (radial) w Groove.
B, oil tank located in the upper and lower bearing binding site (on both sides). Oil tank with circular wedge, tile joints to the lateral depth by General 1~3mm. Depending on the bearing size, oil Groove width is generally 8~40mm. Oil tank with unilateral from the dimensions of the bearing surface is generally 8~25mm. These requirements are usually marked clearly on the drawings. Tanker with length of bearing axial length of about 85%, is a way to save for a larger band of lubricating oil sump, bearing and shaft lubrication and cooling, oil is typically used by machining, Machinist hand processing.
(2) oil wedge. Lubricant wedge in access point connection and bearing a value within the sump, by hand scraping together (commonly known as scraping). Its primary role has two, keep oil cooled bearing and shaft, the second is to use the wedge angle of the arc, in the axis of rotation, led by oil, by the axial width of the face, connecting continuous strip to host part, there are substantial good lubrication of the bearing and shaft. Lubricant wedge section is made up of two irregular arcs a wedge angle of the arc, it brought the oil tank and connecting bearing contact surface smooth. And oil tank with connecting parts to blew some more, and connect the tank with processed corners scraped, transition Central lubricating wedge angle to the contacts, scraping into the wedge angle of the arc-shaped. Oil tank with lubricating wedge angle connection sizes, depending on the bearing size, generally between 0.10~0.40mm. Scraping lubricating wedge angle, bearing fine shave at the end of basic, easy to scrape ahead.
(3) the bearing clearance and backlash
A, top clearance of the bearing, in drawings provided in the light of experience desirable shaft diameters of 1 ‰ ~2 ‰, speed should be. Load and oil viscosity in the context of this selection. High quality, high-precision machining of axle, the value of which fell to 0.5 per thousand.
B, side clearance on the drawings provided, on each side for clearance of one-second. Side clearance required scraping out as needed. But not when scraping Bush backlash, by scraping when Bush, need to determine shaft in the correct location within the range of 180 °, requires side clearance of sites at this time should be used temporarily as the axis position, upon completion of the basic Bush scraping, gently scrape out the backlash. Backlash part w the surface extends to the provision of contact angle, axial connects with the oil tank with lubricating wedge angle, this site is not intended to be contact with the shaft, scraping should pay attention to this point. Backlash of purpose, is to lose heat, lubricant this part out and carry away the rejected heat. Backlash is not opened too much, which causes the oil go in huge amount from the backlash that reduce the amount of oil required for the shaft and bearing, it should pay particular attention.
3, split bearing the scraping process
(1) the rough shave Bush. First new together, top, bottom, inside micrometer measuring hole and axle for comparison, determine the amount of crude scraping.
A upper and lower machining knife w lightly scrape it again, all tile surface should be requested to scrape, scraping even, machining marks scraped.
Painted on the b axis, and Watts, Watts developed under point on rough blow several times, then upper and lower respectively, set to w and w lid, paint on the tile, bearing heavy scraping, and after researching points evenly distributed contact area, can be transferred to the fine shave. Rough shave should pay attention, w may not be part of the scratch, requires full access to the range of 180 °.
(2) fine bearing scraper. Fine scratch when Bush, upper and lower pad (tile joints) bushing at both ends after assembling scraping, paint on the tiles, with bearing point. Start clamping Assembly, clamping force should be uniform, axis not too tight, can roll, scrape with the withdrawal of mats, with the pressure. You should also be careful not to scrape, after repeated cuts after scraping, w contact surface spots evenly and more dense.
(3) precision bearing scraper. Finish scraping the purpose of contact spots and scraping contact area meets the requirements of drawings provided, research methods and the rough scrape the same ideas from big to small, from shendao shallow, from sparse to dense, big ideas in the cutting in the scraping process, available blade breaking off and becoming dense small ideas, through a series of scraping of the cut, gradually scraping up to requirements. To be at the end of the finishing blow, lubricant wedge (open mouth), backlash scrape out, bring it to Bush's performance, which is very important.
Cut bearing scraper, in the rough shave and fine scratch to taking associated with shaft size, such as pitch deviations, contact condition of gear tooth surfaces and so on, so that the axis position accuracy. Small accumulated errors caused by machining, can be further eliminated by scraping. A larger error, cannot be addressed by scraping.



Other News:
Split bearing Assembly
Rolling bearing improper installation failure
Non-standard bearing fatigue testing and fault handling methods
NSK Bearing clearance rate and supporting instrument applications
Effect of enhancing performance of thrust ball bearing surface of life
Miniature bearing selection and use of methodology and process approach
Study on the relationship between NSK bearing corrosion and the surrounding humidity
Angular contact ball bearings with the use of the installation