Actuating system and have self-propelled construction machinery of actuating system

The utility model provides an actuating system especially is used for self-propelled construction machinery, especially road roller, and this actuating system includes: a power devic. At least one hydraulic circuit, this hydraulic circuit have can be by power device driven hydraulic pump, and hydraulic drive auxiliary unit, it has hydraulic pump / motor sub-assembly and at least one pressure fluid accumulator, wherein hydraulic pump / motor sub-assembly with or can couple in order to be fit for the driven mode with power device or at least one hydraulic circuit, wherein hydraulic pump / motor sub-assembly can operate as the pump with at least one pressure fluid accumulator of loading through power device or at least one hydraulic circuit under loading running state and can regard as the motor operation to think that at least one hydraulic circuit's hydraulic pump provides the drive and assists the moment of torsion down at the supplementary running state of drive, the characteristics of this actuating system are that the pump operation can be regarded as so that the fluid is followed in fluid container output and the input fluid container to hydraulic pump / motor sub-assembly under circulation running state.