The backing bearings ( Jimmy's bearing) - bearing knowledge

As the market is on the surface of cold rolled product quality, thickness tolerance, and plane degree increasing, especially in plate and strip is more strict. Drive the mill equipment from two roll to roll ( Eight roller, twelve roller, 18 roller, roller, 20 36 roll) Development in order to allow for rolling out the thickness is thinner, tolerance smaller and better surface quality of the products. Thus puts forward higher requirements on the bearing, especially of backup roll bearing. And backing bearings is recognized worldwide as the preferred more mill of backup roll bearing, which requires the backing bearing must have very high accuracy. Feature: when may withstand the bigger radial load when running accuracy grade is superior to the p4 level when bearing outside diameter directly used as roller surface was not separable, can repair installation features: does inner ring and shaft for the loose fit when every 3 to 7 for a group, in the form of group installed on the shaft bearing has a sequence number in each group, installation not upset when bearing inner ring when the maximum thickness of installation when all bearing inner ring marking must be in the same position assembly accuracy: bearing itself requires very high accuracy, especially inside to the outside after eliminating radial clearance section height ( T value) Especially important, on each axis, control the adjacent bearing T value are 0. Less than 002 mm, entire group control in 0. Within 005 mm ( Figure B - 3) 。 Lubrication, lubrication effect is good or bad, directly also use lifespan of bearing. The lubrication effect is good or bad in addition to the lubricant itself performance and lubrication method, bearing lubrication is the main structural design factors, the number of the oil hole, size, location, directly affect the lubrication effect, backing bearings and lubrication design should be confirmed before the lubricant performance way. Backing bearings three lubrication way when rolling emulsion lubrication is the most economical way of lubrication, no sealed backing bearings use its lubrication method, more need larger flow of emulsion fast through internal bearing lubrication and cooling effect. When circulating oil lubrication main lubrication with the backing of lip seal bearing, lubricating oil flows through the bearing internal heat can be taken away, and then to lubricating oil base station cooling cycle. Can use higher viscosity of lubricant, make the relative with emulsion lubrication bearing life has greatly improved. When main lubricating oil and gas lubrication with the backing of lip seal bearing, use clean and dry compressed air to blow in lubricating oil bearing, the bearing internal pressure and the lubricant adhesion to the bearing surface, and prevent the invasion of alien invaders, its high lubrication costs, but the most ideal lubricating effect. Maintenance and repair: as the backing bearings installed in on the supporting roller of roller mill, the distribution of roll position different must stress, which creates a bearing degree of wear and tear, backing bearings after using 2 cycles, it should be on supporting roller bearing of the bearing and bearing lower support roller bearing position swap, each cycle for inner ring 90 ° rotation, so that you can keep the bearing wear as much as possible. Because many mill rolling material demand is higher, after a certain period, due to the bearing wear, all aspects of accuracy is reduced, when that doesn't meet the requirement of the rolled material, bearing must be reground, restore precision. , ring and rolling body has no obvious pitting and spalling trend before, only need grinding outer ring ( Because of special heat treatment process, outer ring is grinding times keep hardness is consistent with the original) Surface can restore bearing accuracy. For outer ring, rolling body loss, severe spalling and inner ring pitting or peeling off the whole rent backing bearings, need to make new parts and regrouping, repair. DMD in multi-roll mill backing bearing manufacture and repair field has rich technical experience, the specific technical data, please consult the dmo department.