Flywheel excavator

Abstract

A hybrid construction machine is provided. The machine includes a prime mover, at least one fluid pump, at least one fluid actuator, a swing motor, a first flywheel, and a second flywheel. The prime mover drives the at least one fluid pump. The fluid pump provides pressurized fluid to drive the at least one fluid actuator. The returning fluid from the at least one fluid actuator can be used to drive a swing motor, which in turn drives a swing structure. Further, the second flywheel is also coupled with the prime mover. The second flywheel can be configured to store the energy when the prime mover is driven by the at least one fluid pump. The at least one fluid pump is driven by the return fluid from the at least one fluid actuator.

What is claimed is: 
     
         1 . A hybrid construction machine having a swing structure, a lower travel structure, and an implement system having at least one work tool wherein the swing structure can rotate with respect to a the lower travel structure to rotate the work tool from a first position to a second position, the hybrid construction machine comprising:
 a prime mover;   at least one fluid pump wherein the fluid pump is driven by the prime mover;   at least one fluid actuator wherein the fluid actuator is driven by the fluid pump;   a swing motor, the swing motor driven by a return fluid from the at least one fluid actuator;   a first flywheel for driving a swing structure, wherein the first flywheel is driven by the swing motor and wherein the first flywheel is coupled with the swing motor via a clutch; and   a second flywheel coupled with the prime mover, the second flywheel configured to store the energy when the prime mover is driven by the fluid pump via the return fluid from the at least one fluid actuator wherein the second flywheel is configured to assist the prime mover during cold start and/or anti-idle.