履带拖拉机无级变速器设计(行星机构设计)

履带拖拉机无级变速器设计（行星机构设计）

摘要

目前国际上大功率履带拖拉机以及部分工程车辆的传动系广泛采用液力变矩器与动力换档变速箱组合形式，即动力机械传动。还有部分先进机型采用了全液压传动技术，其操纵已由手动电液控制或微电脑控制技术方面发展，并取得非常好的效果，大大提高了整机行驶平顺和作业性能，虽然他们都具有无级变速的功能，操纵轻便，整机动力性好，可靠性高，但由于传动系的传动效率较低，直接影响了整机生产率和经济性。

液压机械无级变速器是综合了机械传动高效率和液压传动无级变速两方面优点的新型传动机构。液压机械无级传动是一种多流传动系统，它将功率分为液压和机械两路传递，分流机构分流后液压马达在正向和反向最大速度之间来回无级变速。其每一个行程和行星齿轮机构的一种工况相配合，最两路汇合成由若干无级调速段相衔接并组逐段升高的全程无级变化输出速度。和液力机械传动相比，装载量最大可提高30%，燃油经济性最大可提高25%。

此设计主要是针对行星齿轮机构以及控制部分离合器的设计。对于行星齿轮采用单排的结构形式，这样可以减小整个无级变速器的轴向尺寸，但是为了能够承受较大的和变化的载荷，于是在中心轮的周围均匀地分布着数个行星轮来共同分担载荷。本设计采用3个行星论均匀的布置形式就可以达到要求。其控制部分采用多片的用压力油控制的湿式离合器。离合器随着载荷的增加可以增多摩擦片的对数或增加其径向尺寸。在设计的过程中这两方面是综合考虑的，因为不可能使轴向或径向的尺寸过分的偏大。

关键词：拖拉机，液压机械传动，无级变速器，行星排

DESIGN OF CONTINUOSLY VARIABLE

TRANSMISSION OF TRACKED TRACTOR

（PLANETARY GEARS DESIGN）

ABSTRACT

At present, international large crawler tractors, as well as some works vehicles widely used transmission torque converter with variable power shift speed box combinations, which is the power mechanical drive. There are also some advanced models use a hydraulic transmission technology, which has been manually manipulated its electro-hydraulic control or microcomputer control technology development, and achieved very good results, greatly enhance the overall ride comfort and operational performance, although they have CVT function, manipulating light, whole dynamic, and high reliability, but because the transmission system drive less efficient direct impact on the overall productivity and economy.

Hydraulic machinery CVT is a synthesis of highly efficient mechanical transmission and hydraulic drive CVT merits of the two new motivation - structure. Hydro-Mechanical - drive is a multi-stream transmission, power will be divided into two hydraulic and mechanical transmission path, streaming agencies triaged hydraulic motor in forward and reverse maximum speed between both CVT. Each of its itinerary and a planetary gear mechanism for a state match, most roads converge into two by a number of variable speed converge and the group has to absolutely no higher level of output speed changes. Hydraulic and mechanical transmission, the loading capacity can be increased by 30%, fuel economy can be increased 25%.

This design is mainly directed against planetary gear mechanism and the control of the clutch part of the design. For single planetary gear arrangement of the structure, thus reducing the entire CVT axial dimensions, however, in order to be able to make and take greater changes in the load, So in the center of the

round around evenly distributed several planetary gear to load shared. The three designs on the planet uniform layout can meet the requirements. Clutch with load increasing friction can increase the number of tablets or increase its radial dimension. In the process of designing these two aspects are considered, as it is impossible to make radial or axial dimensions excessive.

Key words：tractor，hydro-mechanical transmission，continuously variable transmission, planetary gears