松软地面履带车辆差速转向实际载荷比的研究

Research on actual steering power ratio of differential steering mechanism of tracked vehicle on soft ground

为了更好地分析动力差速转向机构的转向性能,对试验样机在松软土壤上进行了试验,得到了实测载荷比与转速比、打滑率、转向半径、转向系数等影响因素的定量关系。试验结果表明,小半径差速转向时,低速侧履带的滑转程度大于高速侧履带的滑转程度,但载荷比和滑转率的变化关系不明显;大半径转向时,载荷比越大,低速侧履带的滑移越大,高速侧履带的滑转越大。转向时的实测载荷比随着实测转向半径的增加而减小,载荷比和转向系数亦满足理论射线关系。该文通过理论与试验研究为履带车辆差速转向机构的设计和转向性能的改进提供了一定的理论依据。

Tracked vehicles can steer at any turning radius in small plot adopting differential steering mechanisms. In order to analyze the turning performance of differential steering mechanisms on tracked vehicles, tracked prototype experiments on soft terrain are performed. After analyzing the research results of scholars in the field at home and abroad, we further studied the relationship between steering power ratio and turning radius, skid ratio and steering coefficient. We built the tracked experimental prototype and connected test equipments to it. Dual-power is input into prototypes, rotational speeds, and moments are recorded by hall rotational speed sensors and self-made moment sensors, respectively. The test methods of turning radius, skid ratio, and steering coefficient are introduced. Because the existence of the skid of two tracks, there is a difference between theoretical steering power ratio and experimental steering power ratio. Through analyzing the experimental data, the relationship curve between experimental turning radius and experimental steering power ratio can be derived. Whether being steered differently in small turning radius or in large, experimental steering, power ratio decreases as experimental turning radius increases. In different turning radius, comparison theoretical steering power ratio with experimental steering power ratio is acquired. Through analyzing the diagrams of the relationship between experimental steering power ratio and skid ratio, we know that the skid ratio of the low-speed track is more than that of the high-speed track when experimental prototype steered in small radius. But variation trends between steering power ratio and skid ratio is not obvious. It is difficult to know how the skid ratio affected the steering power ratio. With the steering power ratio increasing, there is also an increasing trend both for the skid ratio of low-speed track and the skid ratio of high-speed track when experimental prototype is steered in big radius. Through the test data, we can also know the relationship between experimental steering power ratio and steering coefficient in different turning radius, and figure out the radial images of them. The analysis shows that the experimental relationship between steering power ratio and steering coefficient is in accordance with theoretical radial relationship between them. The test results also indicate that maximum value of steering power ratio of tracked prototype adopting differential steering mechanism is less than 4. Different degree slippages of the two tracks and different experimental prototypes will lead to a different turning radius. At the same time, steering power ratio has relations to steering coefficient, turning radius, and skid ratio. Due to the different degrees of skid ratio on low-speed and high-speed tracks and different track gauges in experimental steering, the experimental ray and theoretical ray of steering power ratio and steering coefficient are also slightly different. Combining theoretical deduction and quantitative analysis of the relationships between experimental steering power ratio and influencing factors, research results can enrich differential steering theory of tracked vehicles for adopting differential steering mechanism. It will pave the way to further evaluate turning performance of vehicle tracked for adopting differential steering mechanism, and further compare the differential steering with traditional clutch-brake steering.