WORK MACHINE

To provide a work machine capable of suppressing deterioration of a closed circuit pump.SOLUTION: A work machine includes a hydraulic actuator, a closed circuit pump connected to the hydraulic actuator by a closed circuit and supplying and discharging working fluid to and from the hydraulic actuator, an opened circuit pump connected to the hydraulic actuator by an opened circuit and supplying the working fluid to the hydraulic actuator, a charge pump, a charge flow channel for guiding the working fluid discharged from the charge pump to the closed circuit, a pressure sensor for detecting a pressure of the charge flow channel, a surplus oil discharge device for discharging the surplus working fluid in the closed circuit to the charge flow channel, and a controller for controlling discharge capacity of the closed circuit pump and the opened circuit pump. The controller determines whether or not the pressure of the charge flow channel detected by the pressure sensor is less than a pressure threshold value, and increases the discharge capacity of the opened circuit pump when the pressure of the charge flow channel detected by the pressure sensor is decreased from the pressure threshold value or more to less than the pressure threshold value.SELECTED DRAWING: Figure 6 【課題】閉回路ポンプの劣化を抑制可能な作業機械を提供する。【解決手段】作業機械は、油圧アクチュエータと、油圧アクチュエータに閉回路で接続されて油圧アクチュエータに対して作動油の給排を行う閉回路ポンプと、油圧アクチュエータに開回路で接続されて油圧アクチュエータに作動油を供給する開回路ポンプと、チャージポンプと、チャージポンプから吐出された作動油を閉回路に導くチャージ流路と、チャージ流路の圧力を検出する圧力センサと、閉回路の余剰な作動油をチャージ流路に排出する余剰油排出装置と、閉回路ポンプ及び開回路ポンプの吐出容量を制御するコントローラと、を備える。コントローラは、圧力センサにより検出されたチャージ流路の圧力が圧力閾値未満であるか否かを判定し、圧力センサにより検出されたチャージ流路の圧力が圧力閾値以上から圧力閾値未満に低下した場合、開回路ポンプの吐出容量を増加させる。【選択図】図６