机器元素设计|门机械基本概念

1.In majority of machine members, the damping capacity of the material should be zero.
2. At quite low temperatures (say -75°c) the notched bar impact value of steel decreases significantly.
3. The crest diameter of a screw thread is same as major diameter.
4.如果D是螺栓孔的直径，那么对于爆的管接头被泄漏，螺栓的圆周间距应为20°D - 30˚D。
5. Muntz metal contains copper-zinc.
6.。A Babbitt is antimony bearing lead or tin alloy.
7. Steel balls for ball bearing are manufactured by cold heading.
8. The blow off pressure of a safety value is 106% of boiler working pressure.
9. A foundation bolt with a circular end is secured to the floor by means of a steel cotter. If the pull on the bolt is 14000 kg, the diameter of the bolt should be 60 mm.
10.如果皮针接头，销最有可能在双剪切中失效。
键被切割为轴和集线器是沉没的钥匙。
12.当需要轴和轮毂之间的轴向相对运动时使用样条键。
13.花束轴通常用于汽车。
14.通用联轴器/钩子的关节用于非共线轴。

15.在法兰耦合时，最弱的元素应该是关键。
16. Turn buckle has left hand threads on one end and right hand threads on other end.
17.弹性螺母是一种锁定装置，螺母具有硬纤维或尼龙，螺母凹陷，随着螺母拧在螺栓上，拧紧导致紧密抓握。
18. Treating the weld as a line, the moment of inertia about center of gravity of a circular weld of diameter d, would be πd3/4.
19. A single ply leather belt running at a belt velocity of 300 ft/min is likely to transmit per inch of width 4.0 HP.
20.对于两个板的对接焊接，每个板厚25毫米，最好的工艺将是电渣焊。
压缩构件倾向于在最小血管半径的方向上弯曲
22.垫圈的直径通常略大于螺栓的直径。
23. A reinforced concrete beam is considered to be made up of heterogeneous material.
24.根据欧拉理论，柱的临界长度由PC =π2EI/ L2给出。
25. Rankine formula is valid up to slenderness ratio of 120.
26.柱的细长比是支柱/最小环状半径的长度。
27.在轴承的流体动力学中，通过轴的旋转仅产生油膜压力。
28. If P = bearing pressure on projected bearing area, z = absolve viscosity of lubricant, and N = speed of journal, then the characteristic number is given by ZN/p.
29. The rated life of bearing changes inversely as cube of load.
30.油性轴承不需要外部供应润滑剂。
31.在交叉或常规划线绳索的绳索方向与支架的扭曲方向相反。
32.手表的齿轮通常是通过螺旋角制造的。
33.用于低频和中等速度发动机的凸轮类型通常是谐波的
34. The form coefficient of a spring is capability to store energy.
35.在Wit值得迅速的回报动作中发现了加速的科里奥利组分
36.材料的冷加工增加了疲劳强度。
37. A Babbitt is antimony bearing lead or tin alloy
38. Addendum of a cycloidal gear tooth is epicycloids
39. Spiral gears are suitable for transmitting small powers
40.随着泵的速度增加其NPSH（净积极吸头）需求增加
41.如果不满足泵NPSH要求，它将被空化
42.衬套滚子链用于电动机循环。
43.用于起重机应用的链条的工作负荷以Cm的直径表示，并给出500乘以直径的平方。
44. If a square key and shaft are to be of the same material and or of equal strength, the length of key would be 1.23d, d=diameter of shaft
45. In a standard coarse thread bolt the stress concentration is maximum at root.
46. Fatigue strength of a surface may be increased by polishing the surface
47. The maximum deflection allowed in gantry girders is L/1000
48. The maximum size of the fillet weld that can be used at 3 mm
49. The maximum size of fillet weld that can be made in single pass in 6 mm
50.指定为50毫秒8的轧制钢平面表示平坦50毫米宽，厚8毫米。
51.柱状接头用于增加柱的长度
52. The minimum thickness steel member exposed to weather and accessible for painting is 10 mm
53. For determination of allowable stress in axial compression, IS: 800-1962 has adopted secant formula
54.对于精确的，切割齿轮在高达20米/秒的速度下操作，速度因子V，由6/6 + V给出
55.零轴向推力herinnghbo经验ne gears
56.为了实现流体摩擦的优点，必须在轴承中具有平行的油膜是必要的
57.轴在轴承慢速旋转的轴上旋转，将朝向轴承和金属与金属接触的左侧
58. Bearing characteristics number relating Z-absolute viscosity of lubricant, N-speed of journal and p-bearing pressure on projected bearing area is ZN/p