中文摘要：

液压变压器是液压系统中的新兴元件,可被用来改变系统压力和回收系统能量。目前,在世界节能减排大环境下,液压技术也有了新的突破,出现了能回收系统多余能量的CPR系统。液压变压器是CPR系统的核心元件,它的性能是推广具有环保性质的CPR系统的关键,液压变压器成为研究热点之一。回顾了国外液压变压器的研究进展和概述中国研究情况,将液压变压器分成直线式和旋转式2种类型。通过引用专利,讲述了传统型旋转式液压变压器的出现和发展,评价了它的特征,指出不适合用于CPR系统的原因。以专利为基础,介绍了新型旋转液压变压器的出现,评价了它相对于传统型旋转液压变压器的优点,指出它更适合于CPR系统。分别详细介绍了新型液压变压器的3代发展史和最新进展。对比节流和变压2种压力调节方式,揭示液压变压器的一般性变压原理。在液压变压器分类的基础上,推导各液压变压器的工作原理。阐述液压变压器的特点,并用实例说明在工程机械中应用新型液压变压器能带来显著的节能效果,验证新型液压变压器适合于CPR系统。总结新型液压变压器目前存在的关键问题及其产生原因。最后,指出流量控制问题的解决使得新型液压变压器从变压元件进化为变功率元件,新型液压变压器未来还有诸多需研究和改进的地方。

英文摘要：

In the hydraulic system,the hydraulic transformer is a newly developing component,which can be used to convert fluid pressure and recover energy in the system.Currently,hydraulic techniques make a new breakthrough in developing a common pressure rail（CPR）system that can recover the extra energy in the environment where energy saving and emission reduction is needed in the world.The hydraulic transformer is the core of CPR system and its performance is a key to promote the CPR system that embodies environment protection.It has become a research focus.In this paper,research development of hydraulic transformer was reviewed at home and abroad.The transformer was classified as linear one and rotary one.Invention and development of the classic rotary hydraulic transformer were described and its attributes were analyzed by referring patents.And why it is not appropriate for the CPR system was pointed.Invention of the new rotary hydraulic transformer was introduced and its advantages compared to classic rotary one were evaluated based on the patents.It was pointed why the new one is appropriate for the CPR system.Its three generations and new progress were introduced in detail.The two pressure adjusting ways including throttling and transforming were contrasted to the present general transformation principle of hydraulic transformer.The different working principles of hydraulic transformers based on the classification of hydraulic transformer were derived.The characteristics of new hydraulic transformer were elaborated.The case shows that the new transformer can bring a remarkable energy-saving effect in engineering machinery.So,it is very appropriate for the CPR system.Besides,current key problems and their causes of the new transformer are concluded.At last,it is pointed that the solution of the flow control issue makes the new hydraulic transformer evolve from pressure transducer into power transducer,and there are many spots to research and improve in future.