| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a pump device that discharges air remaining in an inner peripheral space on an inner peripheral side of a pump chamber in a pump casing, to the pump chamber in a relatively short time. <P>SOLUTION: The pump device 1 includes a pump casing 2 having a partitioned chamber 10, and a rotor 12 having an impeller 11 on an outer circumference part. An annular projection 15 of a lower casing 4 constituting the pump casing 2 and a lower annular end face 11a of the impeller 11, and a lower end face 17a of an annular projection 17 of an upper casing 5 and an upper annular end face 11b of the impeller 11 form an annular microgap 16, which face each other across a first gap G1. The inside of a pump chamber 19 is partitioned into a pump chamber 19 in an outer circumferential side of the annular microgap 16 and an inner peripheral space 20 in the inner peripheral side. A first communication groove 24 connecting the pump chamber 19 with the inner peripheral space 20 is formed in the annular projection 15 of the lower casing 4. Air retained in the inner peripheral space 20 is discharged to the outside through the first communication groove 24. <P>COPYRIGHT: (C)2012,JPO&INPIT |
