| 摘要 |
PROBLEM TO BE SOLVED: To prevent wastage of a mechanical seal caused by pressure of pressurized water by communicating an inner space with a suction flow passage of a pump with a communicating pipe, in a pump wherein a seal box is formed on a pump chamber outer wall of a driving shaft inserting part and the mechanical seal is stored in the inner space. SOLUTION: A pump P for fire fighting is driven through a transmission case 1 by a power source such as an engine, and a centrifugal impeller 11 is arranged in a pump chamber 10 having a suction flow passage 2 and a discharge flow passage 4. A seal box A integrated with an outer wall of a pump chamber is formed on an outside of the pump chamber 10, and the transmission case 1 which serves as a bearing box on an outside of the seal box A. An inner space S of the seal box A and the suction flow passage 2 are communicated and connected with/to each other through a communicating pipe 36 in which a check valve 37 and a safe part 38 are interposed. Pressurized water which flows in the seal box A is discharged to the suction flow passage 2, and thereby, it is possible to prevent excessive water pressure from acting on the mechanical seal M and the like.
|
