Circulation pump

摘要

An electric pump has a pump casing, a sealing plate, an impeller and a motor for driving the impeller. The pump casing has a main body. A recess is formed in the main body and with the sealing plate defines a pump chamber. A suction port is connected to the pump chamber by a suction channel and a suction passage formed in the main body. A discharge port is connected to the pump chamber by a discharge channel. The suction passage extends axially from the recess. The recess, suction passage, suction channel and discharge channel are all shaped in a manner allowing the pump casing can be molded as a monolithic structure in a single injection molding process.

主权项

1. A pump comprising:
a pump casing; a pump chamber formed in the pump casing; an impeller disposed within the pump chamber, the impeller having a plurality of vanes forming an inlet and an outlet; a sealing plate, forming one side of the pump chamber; a motor for driving the impeller; wherein the pump casing is a monolithic object comprising: a main body having a first surface, a recess in the first surface, a suction port, a suction channel, a suction passage, a discharge port, and a discharge channel, wherein the recess forms a first opening in the first surface, the first opening is closed by the sealing plate to form the pump chamber, the recess having a second opening in a second surface opposite the first surface and a wall connecting the first surface to the second surface; the suction passage communicates with the recess via the second opening and is aligned with the inlet of the impeller; the suction port is connected to the suction passage by the suction channel; the discharge port is connected to the recess by the discharge channel which extends from a third opening formed in the wall of the recess; the diameter of wall of the recess remains the same or decreases along a direction from the first surface to the second surface; the diameter of the inner surface of the suction passage remains the same or decreases along a direction away from the recess; the inner diameter of the suction channel remains the same or decreases along a direction towards the suction passage; and the inner diameter of the discharge channel remains the same or decreases along a direction towards the recess; wherein the main body further comprises a first ring projecting into the recess from the second opening, and the impeller further comprises a ring-shaped end surface surrounding the inlet and a second ring projecting from the end surface and surrounding the first ring, the second ring faces the first ring across a radial gap, the radially inner end of the end surface of the impeller extends closer to the axis of the impeller, compared to the radially inner end of the first ring.