Pump system and axle-driving system

A pump system comprising:

• a base housing which has an input portion operatively connected to a driving source and which is capable of being directly or indirectly attached to a support member;
• a pump unit which has first and second pump shafts, first and second hydraulic pump bodies respectively driven by the first and second pump shafts, and a pump case surrounding the first and second hydraulic pump bodies, the pump case being detachably coupled to the base housing;
• a PTO unit having a PTO shaft and a PTO clutch mechanism accommodated in the base housing in a state of being supported by the PTO shaft;
• arid
• a power transmission gear train which transmits a power from the input portion to the first pump shaft, the second pump shaft and the PTO shaft, and which is accommodated in the base housing, wherein
• the power transmission gear train has first and second transmission gears meshed with each other,
• the base housing has a narrow gear accommodating space surrounding a region including a mesh point between the first and second transmission gears, a PTO clutch accommodating space which surrounds the PTO clutch mechanism and which is fluidly communicated with the gear accommodating space, and a pair of first and second suction/discharge ports which fluidly communicates the gear accommodating with an outside of the housing,
• the first suction/discharge port is positioned in an opposite side to the PTO clutch accommodating space with the mesh point between the first and second transmission gears interposed therebetween, and
• a first fluid groove extending from the first suction/discharge port to the PTO clutch accommodating space via the mesh point is formed in at least one of a pair of inner surfaces of the base housing, the inner surfaces defining the gear accommodating space and facing to each other with the first and second transmission gears interposed therebetween.