Wheel hub bearing failure are common

Wheel hub bearing common failure - 2019 10 - 18 common failure mode of fatigue failure is one of the most common failure forms of rolling bearing, often show the inner and outer raceway or roller surface has crack or flake material. Early fatigue performance for a series of discrete, irregular pits, along with the degree of fatigue, pit gradually even piece, causing a large area of spalling. Rolling bearing in the process of high speed rotating roller and the inner and outer raceway small contact area and contact stress is large, in the long run under the action of alternating stress, the contact surface will produce crack, then gradually produce pits, until the flake material. The main cause of peeling or force poor lubrication is installed. Wear failure wear is a different failure forms, is with journal bearing inner ring, outer ring, rolling body, keep frame due to mechanical causes or lubrication impurities caused by a kind of surface wear. Under the poor working environment, particles mixed into the bearing of the working face in the middle of the lubricating oil, which will produce between rolling element and raceway abrasive wear, rolling body and roll channel exists uneven size, depth of scratches. The existence of abrasive wear is the root cause of failure is. Plastic deformation and plastic deformation is bearing rotational speed is low or intermittent oscillation, in large under static load or shock loading, can make the bearing raceway and rolling body contact of the local stress exceed the material yield limit, produce plastic deformation, Raceway surface deformation pits) , and make the bearing violent vibration and noise in operation, if the deformation exceeds a certain range, will cause the bearing cannot work normally. On the bearing of this kind of situation usually happens in a low speed. Agglutination agglutination occurred in rolling contact between two surfaces, as on the surface of a metal stick to a surface phenomenon. When the roller in the cage stuck, due to bad lubrication, high speed and the effect of inertia force, formed on the cage material adhesion to the roller end face spiral porphyritic agglutination. Fracture rupture and crack of bearing parts are mainly caused by grinding or heat treatment, also have a plenty of due to the large runtime load, high speed, poor lubrication, or assembly, stress concentration in the bearing parts, cracks, and finally lead to fracture bearing components. Bearing vibration mechanism of bearing structure caused by the vibration of the rolling bearing in the process of work, each element of the load and the stress of the real time is changing. After the ball into the bearing area, the load is gradually increased from zero to the maximum value and then gradually reduced to zero. In terms of rolling body, his load and the change of stress is a cyclical instability. In a different position in the number of ball bearing is different, this will result in changes of bearing stiffness that cause the axis's gyrations. Causes the manufacturing and assembly of the bearing vibration in bearing manufacture process, machine and tool system to produce vibration resulting in processing surface waviness. When bearing running, rolling body, between the outer ring rolling. Bearing surface of the rolling process was very smooth, but from the point of microcosmic, still rugged, especially the material surface fatigue to rack, rough situation is more serious. Rolling element in turn, these concave and convex surface are produced by alternating exciting force. In the process of bearing manufacturing, resulting in rolling body sizes the support stiffness of the axis of swing and change. The periodic force of catastrophe, lead to bearing vibration. Faults caused by the vibration of the rolling bearing in the process of actual operation, such as crushing, fracture, spalling failure or a foreign body into the resulting vibration, it reflects the bearing damage, the vibration information contains the running state of rolling bearing. This kind of vibration generated by the vibration signal can be used for monitoring analysis of the fault. Rolling bearing in the process of operation, due to the rotation of the shaft, roller, and between the outer ring rolling. When rolling surface damage occurs, rolling body turns, in the surface will produce a kind of alternating exciting force. Due to the damage on the surface of the roll shape is no rules, so the vibration of the exciting force of the random vibration is made up of multiple frequency components. Turn from rolling bearing vibration generation surface condition as you can see, the mechanism of rolling bearing surface damage morphology and shaft rotation speed, determines the frequency spectrum of vibration force; Bearing and the shell, decided the transfer characteristic of the vibration system. The final decided jointly by the above two vibration spectrum. Is caused by abnormal bearing vibration frequency is damage by the rotation of the shaft speed, part of the form and the bearing and the shell to transfer characteristics of vibration system.