Hybridization is an effective method to reduce fuel consumption and emissions of toxic pollutants generated by hydraulic excavators (HEs). This paper first reviews various hybrid HEs architectures with electrical, hydraulic, or flywheel-based energy recovery systems (ERSs). Flywheel-based ERS is not widely used in HEs but has achieved widespread concern in the automotive field. In light of this, the differences between HEs and automobiles are discussed to highlight the potential of flywheel-based ERSs in HEs. Then, the paper compares corresponding energy storage devices in these ERSs from many aspects. The comparison shows that flywheels display many advantages over other energy storage devices. Meanwhile, the drawbacks of flywheels are discussed in detail, indicating that the drawbacks can be offset by other advantages. The results show that the flywheel-based ERS is competitive with the electrical and hydraulic competitors for HEs. Finally, the challenges to the flywheel technology and future work are presented.

混合动力是减少燃油消耗和液压挖掘机（HE）产生的有毒污染物排放的有效方法。本文首先回顾了各种基于电力，液压或飞轮的能量回收系统（ERS）的混合式HE系统。基于飞轮的ERS在HE中并未得到广泛使用，但在汽车领域已引起广泛关注。有鉴于此，讨论了高能汽车与汽车之间的差异，以突出基于飞轮的ERS在高能汽车中的潜力。然后，从多个方面对这些ERS中的相应储能装置进行了比较。比较表明，飞轮相对于其他储能设备显示出许多优势。同时，详细讨论了飞轮的弊端，表明该弊端可以被其他优势所抵消。结果表明，基于飞轮的ERS与HE的电气和液压竞争对手相比具有竞争优势。最后，介绍了飞轮技术面临的挑战和未来的工作。