Abstract: As a key and security system for heavy commercial vehicles, hydraulic power steering system must be given sufficient attention during the development and testing phases. Excessive oil temperature and oil pressure of the hydraulic power steering system will cause irreversible damage to the key components of the system, and even lead to serious consequences. In order to study the extreme performance of the hydraulic power steering system of heavy commercial vehicles, the hydraulic steering system oil pressure and oil temperature changes were collected in a typical vehicle test around the "8". Through design matching and verification, the reasons for the high temperature are summarized and analyzed and corresponding improvement measures are proposed. It has certain guiding significance for the failure analysis and development and design of the steering hydraulic system. As a key and security system for heavy commercial vehicles, hydraulic power steering system must be given sufficient attention during the development and testing phases.

Key words: Heavy commercial vehicle; Hydraulic power steering system; Oil temperature; Flow; Working pressure

摘要： 液压助力转向系统作为重型商用车关键的安保系统，在研发和试验阶段必须予以足够的重视。液压助力转 向系统油温、油压过高会给系统关键零部件造成不可逆的损伤，甚至会导致严重后果。为研究重型商用车液压助力 转向系统的极限工作性能，在典型绕“8”字的整车试验中采集液压转向系统油压和油温的变化情况。通过设计匹 配校核验证，总结分析了产生高温的原因并提出相应的改善措施，对转向液压系统的故障分析及开发设计有一定的 指导意义。

关键词: 重型商用车；液压助力转向系统；油温；流量；工作压力