【導讀】承正常運轉的機會是能夠被提高的。在軸承的使用過程當中，過分的忽視會導致軸承的過。熱現(xiàn)象，也可能使軸承不能夠再被使用，甚至完全的破壞。但是一個被損壞的軸承，會留。通過一些細致的偵察工作，我們可以采取行動來避免軸承的再。或搬運時的損傷及安裝誤差等。診斷失效的原因并不困難，因為根據(jù)軸承上留下的痕跡可。以確定軸承失效的原因。在球軸承的失效中約有40%是由灰塵、臟物、碎屑的污染以及腐蝕造成的。弄清諸如剝蝕和疲勞破壞一類失效的機理，有助于消除問題的根源。剝蝕通常是在載荷超過材料屈服極限時發(fā)生的。種破壞稱為低荷振蝕。外，低荷振蝕產(chǎn)生的碎屑的作用就象磨粒一樣，會進一步損害軸承。消除振動源并保持良好的軸承潤滑可以防止低荷振蝕。持緊密的接觸，并且對防止在設備運輸中產(chǎn)生的低荷振蝕也有幫助。使保持架受力，這會破壞支承架，并加速軸承的失效。材料過早出現(xiàn)疲勞破壞是由重載后過大的預載引起的。擺最小時，軸承的非重復性振擺不能超過。

　　

【正文】 t between inner and outer races． Consequently， lubrication migration and contamination are always problems． Once a bearing is contaminated, its lubricant deteriorates and operation bees noisier． If it overheats， the bearing can seize． At the very least，contamination causes wear as it works between balls and the raceway， being imbedded in the races and acting as an abrasive between metal surfaces． Fending off dirt with seals and shields illustrates some methods for controlling contamination． Noise is as an indicator of bearing quality． Various noise grades have been developed to classify bearing performance capabilities． Noise analysis is done with an Anderonmeter, which is used for quality control in bearing production and also when failed bearings are returned for analysis. A transducer is attached to the outer ring and the inner race is turned at 1,800rpm on an air spindle. Noise is measured in andirons, which represent ball displacement in μm/rad. With experience, inspectors can identify the smallest flaw from their sound. Dust, for example, makes an irregular crackling. Ball scratches make a consistent popping and are the most difficult to identify. Innerrace damage is normally a constant highpitched noise, while a damaged outer race makes an intermittent sound as it rotates. Bearing defects are further identified by their frequencies. Generally, defects are separated into low, medium, and high wavelengths. Defects are also referenced to the number of irregularities per revolution. Lowband noise is the effect of longwavelength irregularities that occur about to 10 times per revolution. These are caused by a variety of inconsistencies, such as pockets in the race. Detectable pockets are manufacturing flaws and result when the race is mounted too tightly in multiplejaw chucks. 8 Mediumhand noise is characterized by irregularities that occur 10 to 60 times per revolution. It is caused by vibration in the grinding operation that produces balls and raceways. Highhand irregularities occur at 60 to 300 times per revolution and indicate closely spaced chatter marks or widely spaced, rough irregularities. Classifying bearings by their noise characteristics allows users to specify a noise grade in addition to the ABEC standards used by most manufacturers. ABEC defines physical tolerances such as bore, outer diameter, and runout. As the ABEC class number increase (from 3 to 9), tolerances are tightened. ABEC class, however, does not specify other bearing characteristics such as raceway quality, finish, or noise. Hence, a noise classification helps improve on the industry standard.