近十几年来,多级油缸在液压电梯方面用得较普遍。当用于直顶式液压电梯时,它仍能保持单级直顶式液压电梯的主要优点。例如井道顶上没有机房、井道顶部不承载、井道断面小等等。多级油缸也同样适用于间接式液压电梯。用于电梯的多级油缸有严格的同步要求,希望各级柱塞不论在上升或下降时均能同步。在其它设备上早已采用的多级油缸通常都是几级柱塞分先后次序动作的,即上升时总是大柱 In the past ten years, multi-stage hydraulic cylinders have been used more commonly in hydraulic elevators. It also retains the main advantages of a single-stage, straight-top hydraulic lift when used on a straight top hydraulic lift. For example, there is no room on the top of a hoistway, the top of a hoistway is not carried, the hoistway section is small, and so on. Multi-cylinder also applies to indirect hydraulic elevator. Multi-stage elevator for elevators have strict synchronization requirements, I hope all levels of the plunger regardless of the rise or fall can be synchronized. Multi-stage cylinders that have long been used on other equipment are usually operated in several orders of magnitude, that is, the large column