Inspection on railway bearing fault inspection, to focus on listening, seeing, touching, twisted, go to check.
　　1 listen
　　Vibration noise when listening to the train′s wheels and bearing friction. Do train station check the first link is the early detection of bearing faults. Vehicles currently in use there are many shortcomings, as tread peeling, local abrasion, resulting in excessive vibration in the use of the wheel, have an extremely harmful effect on NSK bearings and parts. So, when the trains arrival check, effort should be focused on, for bearings vibration of large attention to the detailed examination, early detection of the thermal shaft failure.
　　2 see
　　Bearing fault characteristics of appearance. Failed bearings, are visually reflected. Reflect different failure characteristics are not the same. There are several of these characteristics: coat with sealed cover of axis surface temperature anomaly, bearing clearance, oil spills, discoloration, bearing out, damaged, corroded, and so on. Check appearance found in fault, they carefully judge to determine accurate parts of the fault.
　　Shaft end clearance between outer ring and two sealing cover too large, check 197,726-bearing vehicles found bearing sealing cap and front and rear clearance is too large, and there are more fats overflow, it is crack on the outer ring of the bearing.
　　Oil leakage. On both sides of the bearing seal cover oil is a common appearance of NSK bearing failure. Discovered oil sealing cap is not loose, after you wipe the grease can be used continues to assemble, but care must be taken to 名称 oil leakage because of the cracks on the outer ring, withdrawal you want scrapped.
　　Crack on the outer ring. Lateral crack 名称 most outer ring groove, somewhat rare in other parts. Outer ring damage mostly to external shocks. Improper lifting, transporting or derail accident prone to outer ring damage.
　　Damaged seals. This is a common fault, if only wire is found broken, missing seals and locking check ears are still key post front cover bolts on six areas, proved not loose bolts, should confirm the bearings to move overseas, such as found to be bearing failure, the axial clearance is too large to be treated as withdrawal.
　　Serious corrosion of bearings. Such failures rare. Application checks if the bearing outer ring rust in serious corrosion pits, should be treated as withdrawal. Galvanic corrosion of bearings. NSK bearings electric erosion was caused by bogie or body welding current through the bearing resulting in the upper part. Bogie top or car body welding job, should prevent the current through the bearing causing galvanic corrosion. Use if wheels are found in the same section of the wheel and rail contact surface and the wheel rim when molten pit of the outside were injured by electrical discharge, the bearings should be check withdrawal decomposition.
　　3 touch
　　Hand axle temperature differential effects of temperature. When hands touch the bearing temperature, to adhere to the more sensitive heat-sensitive fingers back, touch the bearing to the specified site, unusual temperatures to touch both before and after, hands touching time must be summer for more than 3 seconds, winter for more than 5 seconds.
　　4-twist
　　Quality of NSK bearings axle temperature of the overflow. For hot bearings, can be judged through the method of identification of its oil hot box fault. When oil is pale yellow, running in the black shaft temperature overflow; when the water milky white. If the fracture of bearing cage, nut loose particles from the rolling element broken or split of the Raceway, by rubbing metal powder mixed with oil, turn grease into silver, with hands on twisting, or with a blank sample open after you fold the paper, the Sun, grease is silver-grey with gold luster and is particle State.
　　5 RPM
　　Judgment bearing defects. After the top pick, with two hands holding the bearing axially pushed in the lower, with a steel ruler or Vernier caliper measuring bearing clearance, NSK bearing clearance under 0.075~0.54mm. Application by 1mm master. Such as gap, but limited, and to turn around three times more than rotation check the outer ring cracked, such as transverse underworld, used cotton yarn this clean and check again. Rotation should have listened very carefully to the abnormal noise, no crack in the outer ring, but limited axial clearance, resistance is turning freely or turning, but evenly with your hand turned, which is normal, you can release. Outer ring each go to a a Department Shi feel vibration, and has different tone and block Shi, that for both inside and outside roll road split; as turned not freely or fundamental with hand go not moving, or go to a a Department has "card da" sound, again go or reverse Shi in same Department still has this sound Shi, that for roll child or keep frame damaged, has above situation Shi should buckle car for round. To the left after turning three laps, then rotate in one direction and backwards violently reversed, listen for roller impact noise, such as percussion and rotation is very flexible, that is, for lack of oil.