机械原理英文版3齿轮

Text
The lathe is a machine that removes material by rotating the work against a cutter. Parts to be machined can be held between centers, attached to a face plate, supported in a jaw chuck, or held in a draw-in chuck or collet.
Part3 Processing Machine
Unit 1Engine Lathe Unit 2The Non-Traditional Machining Hand-book Unit 3Primary Processes
Unit 1Engine Lathe
Reading Target 1．Illustrate principal parts of an engine lathe and introduce their function. 2．Make you know several methods to hold and move workpieces on the lathe.
The tailstock spindle is a hollow shaft that is mounted in the tailstock body. The left end of the hole is tapered to hold the tailstock or dead center to hold twist drills, etc. , for doing work as mentioned above.
Headstock
The headstock of a lathe is a subassembly that is mounted on the inner ways at the left end of the bed. On a geared-head lathe, the headstock casting supports and encloses a train of gearsspindle at rpm[2] which are suited to the operating conditions of the different jobs routed to the machine.

=（−1）2
z2 z1
⋅ z3 z2′
(1)
100 − n H
= − 30 × 50
− 200 − n 20 × 40
H
n = −95 .65 rpm H
与n1转向相反、 与n3转向相同
(2)
100 − n H
= − 30 × 50
n = 165.22rpm H
200 − n 20 × 40 H
与n1、n3转向相同
太阳轮、行星架为 基本构件
（回转轴线重合）
4
机械原理
周转轮系可分为基本周转轮系和复合型周转轮系 基本周转轮系
---转臂只有一个,太阳轮不超过两个; 复合周转轮系
---若干基本周转轮系串联或并联;
基本周转轮系 差动轮系(Differential gear train， F=2)
根据自由度数目
行星轮系 (Planetary gear train，F=1)
周转轮系+周转轮系
复合轮系
定轴轮系+周转轮系
混合轮系
本教材把两 者统称为
复合轮系
12
机械原理
定轴轮系+周转轮系
周转轮系+周转轮系
13
机械原理
定轴轮系 行星轮系
轮 差动轮系 按轴线是否固定 周转轮系
系
2K-H 复合轮系 3K
的
分 平面轮系 按轴线间的相对位置分
类
空间轮系
14
机械原理
§11-2 定轴轮系的传动比
train ratio of gear train with fixed axis
传动比(train ratio )--轮系中首、末两构件的角速度之比。

2)斜齿圆柱齿轮机构： helical gear mechanism
3)人字齿轮机构： double-helical gear mechanism
2.用于相交轴间传动的齿轮机构
锥齿轮机构：bevel gear mechanism
锥齿轮也称为伞齿轮
直齿锥齿轮机构 曲线齿锥齿轮机构
3.用于交错轴间传动的齿 轮机构 交错轴斜齿轮机构 crossed helical gear mechanism (也称为螺旋齿轮机构)
基圆齿厚
sb ( srb / r ) 2rb inv s cos 2r cosinv cos ( s mzinv )
§10-5 渐开线直齿圆柱齿轮的啮合传动
1．一对渐开线齿廓正确啮合条件 因为 pn= pb pn1= pn2
所以，要使齿轮能正确啮合，必须有 pb1= pb2 又因 pb=πmcosα 所以 πm1cosα1=πm2cosα2 故 m1cosα1= m2cosα2 要满足上式，则应 m1=m2=m ,α1=α2=α 渐开线齿轮正确啮合的条件是： 两齿轮的模数和压力角应分别相等。
（5）齿距：任意圆周上量得的相邻两齿同侧齿廓间的弧长，用pk
表示。(也称为周节)
pk= sk+ ek （6）法向齿距：相邻两齿同侧齿廓间沿 法线方向量得的直线距
离，
用pn表示。
p n= p b
Pb称为基节，指基圆 上的齿距。
（7）分度圆：计算基准圆，用d 和r 表示。 p= s+ e
（8）齿顶高：介于分度圆与齿顶圆之间的轮齿部分的径向高
蜗杆机构：worm and worm wheel mechanism
§ 10-2 齿轮的齿廓曲线
1．齿廓啮合的基本定律

about CAM now. Listen to the conversation and answer the following questions.
1. What is CAD? 2. How do CAD and CAM systems work together in manufacture? 3. What is the main function of CAM?
robot conveyor stamping machine chisel welding steel sheet steering wheel roll engine protective cloth
Chapter 3 Mechanical Designing
Task 2 Listen to the news report and answer the questions.
Task 3 Work in pairs. A is now presenting the prototype of electric scooter to B. Make a conversation with your partner according to the information given below.
3. This symbol warns against dangerous voltage!
Chapter 3 Mechanical Designing
6. This symbol indicates prohibitive actions that must not be performed by the operator.
1. This symbol indicates that lethal accidents or serious injuries may occur if the operating and working instructions are not followed properly.