摘要本文主要是做好了对二级NGW型行星齿轮减速器的结构设计。此减速器适用于冶金，矿山，起重运输，建筑，船舶等机械传动上。通过学习完成了此减速器的设计。

首先简要介绍了课题的背景，目的意义以及齿轮减速器的研究现状和发展趋势并设计了几套传动方案，通过比较各种传动机构，从而确定了传动的基本类型，接着计算高低速传动级的传动效率以便设计计算主要构件。

然后是对传动机构主要构件包括太阳轮、行星轮、内齿圈及行星架的设计计算，通过所给的输入功率、传动比、输入转速以及工况系数确定齿轮减速器的大致结构之后，对其进行了整体结构的设计计算和主要零部件的强度校核计算。并对每章做出一个小结。52553

最后对整个设计过程进行了总结，基本上完成了对该减速器的整体结构设计。此减速器的两大特点：一，为了使三个行星轮的载荷均匀分配，采用了齿式浮动机构，从而实现了太阳轮的浮动；二，内齿圈与箱体采用分离式，通过销将其与上下箱体固定在一起。

毕业论文关键词：行星齿轮，传动机构，结构设计，校核计算

Abstract 

This paper is to design the structure of the two NGW type planetary gear reducer.The speed reducer used in metallurgy,mining,lifting the transport,construction and other mechanical transmission.Through the study completed the design of the reducer. 

First briefly introduces the background of the topic,the purpose and significance of gear research status and development trend of device and designed several sets of transmission scheme,through the comparison of various transmission mechanisms,which determine the basic type of transmission,then calculate the transmission efficiency of transmission level for design and calculation of main components.

Then is the main component of the transmission mechanism comprises a design and calculation of wheel,planet wheel,ring gear and the planetary frame after the sun,given by the input power,transmission ratio,input speed and the condition factor to determine the approximate structure of the gear reducer,to calculate strength design and calculation of overall structure and main parts.And make a summary. 

Finally,a summary of the entire design process,basically completed the design of the overall structure of the reducer.Two major features of this reducer:one,in order to make the load of three planetary wheels uniform distribution,the tooth type floating mechanism,so as to realize the float solar wheel;two,the ring gear and the box body adopts a separate type,through the pin with the upper and lower body are fix together.

Keywords: Planetary gear，Driving  Machanism，Structural design，Checking calculation 

 目  录

第一章  绪论 10

1.1前言 10

1.2 选题的目的和意义 10

1.3 国内外研究现状及存在的问题 11

1.4 发展趋势 12

1.5 本章小结 12

第二章  传动方案的确定 13

2.1 已知技术参数 13

2.2机构布局方案 13

2.2.1 方案一 13

2.2.2 方案二 14

2.2.3 方案确定 14

2.3齿形及精度 15

2.4齿轮材料及其性能 15

2.5 传动比分配