Abstract:

PRSM was a new type of precision threaded transmission mechanisms. Currently， due to the difficulty in grinding small pitch hard tooth profile precision threads， ensuring the machining accuracy of PRSM precision threads was challenging， which led to a significant gap between domestic and foreign products in terms of load-bearing capacity， travelling accuracy and transmission efficiency and other performance aspects. This paper selected typical PRSM products from domestic and foreign markets to conduct statistical， analytical， and comparative research on thread machining errors. First， the axial profile of the screw， roller and nut thread was detected based on the contact measurement method. Evaluation techniques such as gradient threshold method and axis transformation theory were employed to assess and statistically analyze errors including pitch diameter errors， pitch errors， eccentricity errors， and tooth profile angle errors. Based on these analyses， the paper elaborated on the mechanism behind typical irregularities in PRSM thread machining， such as taper in pitch diameters and periodic fluctuations in multi-start thread pitchs. Furthermore， corresponding process optimization strategies were proposed for quality control in thread machining， aiming to support efficient precision grinding and performance enhancement of domestic PRSM threads.

Key words: planetary roller screw mechanism（PRSM）, machining error, statistical analysis, process optimization, precision grinding

摘要：

行星滚柱丝杠副（PRSM）是一种新型精密螺纹传动装置。目前，由于小螺距硬齿面精密螺纹磨削加工困难，PRSM精密螺纹加工精度难以保证，导致国内外产品在承载能力、行程精度及传动效率等性能方面差距显著。选取国内外典型型号PRSM产品开展螺纹加工误差的统计、分析及对比研究。首先利用接触式测量方法检测了丝杠、滚柱及螺母螺纹轴向廓形，并根据梯度阈值法及轴法转换理论等评价技术，对螺纹中径误差、螺距误差、偏心误差及牙型角误差等误差进行评价与统计分析。在此基础上，阐述了丝杠中径锥度、多头螺纹螺距周期性波动等PRSM螺纹典型异常加工结果的产生机理，并针对螺纹加工质量调控提出了相应的工艺优化策略，为国产PRSM螺纹高效精密磨削与性能提升提供了支撑。

关键词: 行星滚柱丝杠副, 加工误差, 统计分析, 工艺优化, 精密磨削