履带拖拉机无级变速器设计(总体设计)

履带拖拉机无级变速器设计(总体设计)

摘要

液压传动可以保证车辆具有稳定最佳的速度，并可准确控制和随意地无级变化，包括零速和倒挡。以较小体积和重量保证大范围无级变速的条件下，其最大功率可以达纯液压功率的好几倍等比连续式初始段的输出转速

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相对平缓，也有较大的输出转矩。单行星排式是由单个行星排和一个机械自动变速器组成。本次设计采用单行星排形式的液压机械无级传动方案。液压机械无级变速器通过调节液压元件的相对排量来实现无级变速的。液压功率分流比定义为液压机械变速器中的液压路的输出功率（即经由液压路传递倒行星排的输入功率）与变速器总输出功率的比值（不计功率损失）。液压机械无级变速器在最小传动比和最大传动比范围内，传动是无级的。液压功率分流比反映了传动系统中的各种工作状态，合理设计机械传动参数和适当匹配变量泵和定量马达，可避免出现功率循环，从而提高传动效率。液压功率分流比越大，那么整个系统的效率越低。

关键词:拖拉机，液压机械传动，无级变速器，传动方案

DESIGN OF CONTINUOUSLY VARIABLE TRANSMISSION OF TRACKED TRACTOR

（SYSTEM DESIGN）

ABSTRACT

Hydraulic drive vehicles can guarantee stability with the best speed and can accurately control and no arbitrary level changes including zero-rate and reverse gear. To the smaller size and weight to ensure that the large scope of the CVT conditions, the maximum power can achieve pure hydraulic power several times. The maiden geometric continuous line of the output is relative moderate, but it’s also a larger output torque. Single planetary-row is composed of row single planet and a mechanical automatic transmission. The single-row form of planetary hydraulic machinery stepless transmission program is used in this design. Hydraulic machinery CVT can achieve the CVT by adjusting the hydraulic components of the relative displacement. Hydraulic power split ratio is defined as hydraulic mechanical transmission of hydraulic road output power (that is, by reversing hydraulic transmission path planetary row the input power) and the total output power transmission ratio (excluding power losses). Within the transmission ratio of hydraulic machinery CVT transmission ratio in the smallest and the largest, transmission is no rank. Hydraulic power split ratio reflects the transmission of the working state, Rational design mechanical transmission parameters and appropriate matching and quantitative variables pump motors, avoiding any power cycle thereby enhancing the efficiency of transmission. Hydraulic power is greater than segregation, then the whole system less efficient.

Key words: tractor，hydro-mechanical transmission，stepless transmission，transmission scheme

目录

第一章前言 (1)

第二章液压机械传动................... .. (2)

§2.1 液压无级传动在小型拖拉机上的应用 (2)

§2.2 重型车辆发展液压无级传动的问题 (3)

§2.3 液压机械连续无级变速传动的种类 (4)

§2.4 液压机械无级传动系统的组成环节 (5)

§2.5 液压机械无级传动的类型 (6)

第三章传动方案与传动参数的确定 (8)

§3.1 几种液压机械无级传动形式 (8)

§3.2 传动参数的确定 (9)

§3.2.1 中心矩和各对齿轮传动比的确定 (9)

§3.2.2 离合器的状态. .. .. .. .. .. .. (10)

§3.2.3 液压泵及液压马达的选择 (11)

第四章齿轮的校核 (13)

§4.1 传动比为i1的齿轮校核.... .. (13)

§4.2 倒挡第一级齿轮传动的校核 (16)

§4.3 倒挡第二级齿轮传动的校核 (17)

第五章液压机械无级变速器的特性分析 (20)

§5.1 无级调速特性 (20)

§5.2 液压功率分流比 (21)

第六章结论 (24)

参考文献 (25)

致谢 (27)