A journal bearing, in its simplest form, is a cylindrical bushing made of a suitable material and containing properly machined inside and outside diameters. The journal is usually the part of a shaft or pin that rotates inside the bearing, as shown in Fig.2.1.
Fig.2.1 Journal Bearing
Journal bearings operate with sliding contact, to reduce the problems associated with sliding friction in journal bearings, a lubricant is used in conjunction with compatible mating materials. When selecting the lubricant and mating materials, one must take into account bearing pressures, temperatures and also rubbing velocities. The principle function of the lubricant in sliding contact bearings is to prevent physical contact between the rubbing surfaces. Thus the maintenance of an oil film under varying loads, speeds and temperature is the prime consideration in sliding contact bearings.
2.2 Words and Phrases
fastener n. 紧固件，紧固零件
classification n. 分类，类别
removable adi. 可移动的，可拆的
semipermanent adj. 半永久性的
cotter pin n. 开口销，开尾销
disassemble v 拆开，分散
rivet n. 铆钉；v. 铆；铆接
weld v. 焊接，熔接
nuisance n. 障碍，损害
rattle v.& n 发出喀啦声，硬物质的撞击声
nut n 螺帽
bolt n. 螺钉，螺栓 v. 用螺栓连接
screw n. 螺钉，螺旋丝杆
lock washer n. 锁紧垫圈，止动垫圈，防松垫圈
resilience n. 弹力，弹性
aluminum n. 铝(金属元素符号)
shaft n. 轴
bearing n. 轴承，支承
gear n. 齿轮
cam n. 凸轮，靠模
clutch v.& n. 抓住，离合器
cold-roll v.& n 冷轧，冷轧机
forge v.& n 锻造，打制
flexible adj. 柔软的，适用性强
friction n. 摩擦
brake v. 破坏，折断，损坏
wear v.& n 磨损，耗损
arrangement n. 布置，排列
contaminant n. 杂质，污染物质
sealing arrangement n. 密封装置
hostility n. 敌意，恶劣
appreciation n. 评价，欣赏
interference n. 干涉，过盈
fretting n. 腐蚀，损坏，磨损(微动)
abut v. 邻接，倚靠
chamfer v.& n. 倒角，倒圆，开槽
journal bearing n. 滑动轴承
cylinderical adj. 圆筒状的
lubricant n. 润滑剂，润滑材料
compatible adj. 相适用，和谐的，一致的
2.3 Complex Sentence Analysis
[1] Fasteners are devices which permit one part to be joined to a second part and, hence, they are involved in almost all designs.
① which 引导定语从句修饰devices。
② to be joined to a second part 第一个不定式to 表示目的。be joined to 是介词词组，to 表示“到”的意思。
③ are involved in 表示“涉及”、“包括”的意思。
[2] This change in the length of the bolt can be caused by a number of factors-creep in the bolt, loss of resilience, difference in thermal expansion between the bolt and the bolted members, or wear.
① factors-creep 是复合词，表示“引起蠕动的因素”。
② loss of resilience 表示“弹性丧失”。
[3] In general, the bending deflection of a shaft should not exceed 0.01 in. per ft of length between bearing supports.
① 0.01 in. per ft 表示“每英尺长度
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