分析了伺服系统中丝杠螺母的热特性规律，对丝杠温度场进行了简化建模，以快速准确地预测丝杠温度分布及变化。简化模型能较好地预测丝杠温升过程，但稳态误差较大；通过引进时间修正系数修正了该简化模型，修正后的模型能较好地预测丝杠的稳态温度，但对温度上升过程的预测误差较大；鉴于两个模型的特点，基于分段建模的思想，建立了丝杠温度场分段模型，并辨识了模型参数。实验结果表明，不同单热源实验条件下，预测温度误差值在0.5 ℃以内；双热源实验条件下，预测温度误差值在0.8 ℃以内；显示该模型能较好地预测丝杠温度随时间的变化。

The thermal characteristics of ball screws in servo systems were analyzed,then a simplificated temperature filed model was established to predict the temperature distribution and variations of the ball screws quickly and accurately. The simplified model can predict the unsteady temperature rising of the ball screws, however, there are big errors when the model was used to predict the steady temperature variations of the ball screws. A new simplified model was built by introducing the factor of time modification in the simplified model. The new model has a good performance in predicting the process of steady temperature, however, there exist big errors when the new mode was used to predict the unsteady temperature rising of the ball screws. Based on the performance of the two models abore, a new interval model was also built and the parameters of the new interval model were identified by the LS method. The results show that the error of temperature prediction is less than 0.5 ℃ for a single thermal source, and less than 0.8 ℃ for the double thermal sources.It concludes that the interval model built in the paper has good performance in prediction the temperature variations of ball screws.