摘要随着国民经济的持续发展，机械工业也在不断地发展着，各种设备都在不断地发展，创新着。

特别是在农业方面，拖拉机的应用非常广泛，在一些特定的工作场合，拖拉机体积小，变速灵活，价格成本低廉很受欢迎，越来越多的农业工作者选择拖拉机作为耕田施肥等等的辅助工具。

根据市场调查发现，拖拉机变速器必须满足当今人们对拖拉机速度调节方面的灵活性操控等需求，能够在不改变发动机的扭矩和转速的情况下，改变拖拉机的驱动力和行驶速度；在发动机曲轴旋转方向不变的情况下，使拖拉机前进或后退；在发动机不熄灭的情况下，可使拖拉机长时间停车或进行固定作业。

变速器有自锁功能（只能挂一个挡）、互锁装置和倒挡锁装置。

目前市面上的拖拉机变速器大多都是采用传统的变速结构，在某些特定的区域，这种结构形式的拖拉机变速器非常不受欢迎。

由于以往的拖拉机变速器采用传统的结构形式，这样就造成传动精度不好控制，保养维护费用较高;同时存在一定的安全隐患。

因此，对整机的安全性要求较高，操作时也会给工作人员带来强烈的震动，使得操作很不舒服。

虽然传通的拖拉机变速器传动效率较高，变速效果较好，但是价格也较昂贵，对于一般的用户难以接受。

所以研究一种新式的拖拉机变速器势在必行！本文介绍了拖拉机变速器的结构组成、工作原理以及主要零部件的设计中所必须的理论计算和相关强度校验，该拖拉机变速器的优点是传动链短、效率高、易加工、使用和维护都很方便，较适合在恶劣的环境下工作，最主要的是其传动效率很高。

拖拉机作为农业机械的一种，广泛应用于农业耕作行业等，适用于耕田、播种、施肥，装运等等各个农业领域。

它工作时，发动机通过V带传动带动拖拉机变速器转动，从而间接地带动了拖拉机轮子的转动，这样拖拉机就可以行驶了，通过改变变速器理论的档位来实现拖拉机的前进、后退、加速、减速等等功能。

本文介绍了拖拉机自动变速器的结构组成、工作原理以及主要零部件的设计中所必须的理论计算和相关强度校验，该拖拉机自动变速器的优点是传动链短、效率高、易加工、使用和维护都很方便，较适合在恶劣的环境下工作，最主要的是其传动效率很高。

拖拉机自动变速器作为机械的一种，它工作时，发动机通过V带传动带动拖拉机自动变速器转动，从而间接地带动了拖拉机轮子的转动，这样拖拉机就可以行驶了，通过改变变速箱理论的档位来实现拖拉机自动拖拉机的前进、后退、加速、减速等等功能。

关键词：机械工业；拖拉机变速器；传动机构；传动效率AbstractWith development of all kind of science technology and global economy, Pneumatic manipulator is a automated devices that can mimic the human hand and arm movements to do something，aslo can according to a fixed procedure to moving objects or control tools. It can replace the heavy labor in order to achieve the production mechanization and automation, and can work in dangerous working environments to protect the personal safety, Therefore widely used in machine building, metallurgy, electronics, light industry and atomic energy sectors.The pneumatic part of the design is primarily to choose the right valves and design a reasonable pneumatic control loop, by controlling and regulating pressure, flow and direction of the compressed air to make it get the necessary strength, speed and changed the direction procedurework.The inverted pendulum is a typical high order system, with multi- variable, no n-linear, strong-coupling, fleet and absolutely instable. It is representative as an ideal model t o prove new control theory and techniques. During the control process, pendulum can effectiv ely reflect many key problems such as equanimity, robust, follow-up and track, therefore.This paper studies a control method of double inverted pendulum . First of all, the mathematical mo del of the double inverted pendulum is established, then make a control design to double invert ed pendulum on the mathematical model, and determine the system performance index weight matrix , by using genetic algorithm in order to attain the system state feedback control matrix. Finally, the simulation of the system is made by . After several test matrix value the results are not satisfactory response, then we optimize matrix by using Genetic Algorithm. Simulation re sults show: The system response can meet the design requirements effectively after Genetic Al gorithm optimization. Small twisted paper broken machine for ordinary home, not only can be used for minced meat, can also be used with crushed peanuts, crushed ice, spices and otherfood, small power requirements, powered by the motor drive, reasonable structuredesign. The pneumatic part of the design is primarily to choose the right valves and designreasonable getthenecessarstrengthspeedandprocedurework.The inverted pendulum is a typical high order system, with multi- variable, non-linear, strong-coupling, fleet and absolutely instable. It is re presentative as an ideal model to prove new control theory and techniques. During the control process, pendulum can effectively reflect many key problems such as equanimity, robust, follo w-up and track, therefore.This paper studies a control method of double inverted pendulum . F irst of all, the mathematical model of the double inverted pendulum is established, then make a control design to double inverted pendulum on the mathematical model, and determine delay .Key word: pneumatic manipulator；cylinder；pneumatic loop；Fout degrees of freedom.目录1绪论 (6)1.1拖拉机发展现状 (7)1.1.1拖拉机结构形式的发展 (8)1.1.2 拖拉机变速器的发展状况 (8)1.1.3 课题研究的目的和意义 (8)2 拖拉机变速器的总体方案设计 (10)2.1 变速器的结构形式 (15)2.2.1 变速器内部传动系统的布局................................................. 1错误!未定义书签。

3 拖拉机变速器体传动系统的设计 (14)3.1变速器内部传动系统的具体结构 (16)3.2 各档位的传动路线的确定 (18)3.3 各档位的传动比及其速度的计算 (20)3.3.1 各档位的传动比的确定 (27)3.3.3 各档位速度确定 (27)4 变速器内部传动零件的设计................................................................ 2错误!未定义书签。

4.1 传动轴的设计计算......................................................................... 2错误!未定义书签。