| 摘要 |
PURPOSE:To prevent slide contact and locking of an impeller by incorporating such a construction that the water passage at the peripheral part of impeller, which is formed by casing liner and a casing cover, at its motor side portion has a smaller volume than the portion on the opposite side to the motor. CONSTITUTION:The portion A' of a water passage 13 on its casing cover 12 side shall have a large volume, while the other portion B' on casing liner 11 side a small volume. When the impeller 9 is rotated, the water passing through the passage 13 on its B' side will have a higher pressure than on the A' side. Accordingly this pressure difference will hinder the impeller 9 from shifting to the B' side during pump in operation, because the impeller 9 receives the pressure at its A' side fastened by a nut, not illustrated, so that the impeller 9 will not contact with the casing liner 11. On the other hand, the impeller 9 receiving the pressure on its A' side is hindered from moving by said nut, not illustrated, so that it will not contact also with the casing cover 12. Thus, there is no risk of slide contact or locking. |
