| 摘要 |
PROBLEM TO BE SOLVED: To provide a water pump configured to be capable of reducing consumption horsepower by preventing a discharge amount of the water pump from being excessive relative to a cooling water amount required at the side of an engine.SOLUTION: A water pump 12 is driven by an engine 7, and circulates and drives a cooling water 9 of the engine 7. The water pump is provided with a relief circuit 13 capable of returning some of the cooling water 9 by using a pressure difference from a pump outlet 11 side to a pump inlet side, and is provided with a relief valve 14 capable of opening and closing a flow channel in the middle of the relief circuit 13. |
