IP Library Granted Patent US 7,891,958
Granted Patent B2
US 7,891,958 · App. 11/783,771 · Granted Feb 22, 2011

Impeller pump with reflux passages and apparatus using same

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Quick Facts
Patent No.
US 7,891,958
App. No.
11/783,771
Granted
Feb 22, 2011
Kind
B2
Abstract

A pump includes a pump part provided with an impeller having a plurality of blades for sucking and discharging a liquid; a pump case accommodating the pump part; a rotor installed to the impeller to rotate the impeller; a motor part accommodating a stator disposed around an outer periphery of the rotor to drive the rotor and a driving circuit for controlling the stator; a partition member for isolating the motor part from the pump part to protect the motor part therefrom. The pump further includes a reservoir space disposed in the impeller; an extra passage provided between the rotor and the partition member and connected to the reservoir space to introduce the liquid thereto from the blades; and one or more reflux passages, formed at the impeller, for flowing the liquid in the reservoir space back to the blades.

Claims (22)

1. A pump comprising:

a pump part including an impeller having a plurality of blades for sucking and discharging a liquid;

a pump case accommodating the pump part;

a rotor installed on the impeller to rotate the impeller;

a motor part accommodating a stator disposed around an outer periphery of the rotor to drive the rotor and a driving circuit for controlling the stator;

a partition member for isolating the motor part from the pump part to protect the motor part therefrom;

a shaft fixed to the pump case and the partition member at both ends thereof;

a reservoir space disposed in the impeller;

an extra passage provided between the rotor and the partition member and connected to the reservoir space to introduce the liquid thereto from the blades; and

one or more reflux passages, formed in the impeller, for flowing the liquid in the reservoir space back to the blades,

wherein the impeller is rotatably attached to the shaft and rotates around the shaft.

2. The pump according to claim 1 , wherein said one or more reflux passages are disposed adjacent to the shaft provided at a central part of the impeller.

3. The pump according to claim 1 , wherein the number of the reflux passages are greater than one, and the reflux passages are formed at a central part of the impeller at equal angular intervals.

4. The pump according to claim 1 , wherein a passage is formed outside the extra passage at an inner sidewall of the pump case on a substantially same plane as a fluid flow direction of the impeller.

5. The pump according to claim 1 , wherein the extra passage is formed such that an angle between a liquid flow direction in the extra passage and a liquid flow direction in the impeller is 90° or greater.

6. The pump according to claim 1 , wherein a front shroud is disposed at an upper surface of the blades facing the pump case to cover the blades.

7. The pump according to claim 1 , wherein the impeller has a slide bearing rotating by using the liquid sucked into the pump part as a lubricant.

8. An apparatus comprising:

a pipe in which a liquid circulates; and

the pump according to claim 1 for circulating the liquid in the pipe.

9. The pump according to claim 1 , wherein the number of reflux passages is greater than one.

10. The pump according to claim 4 , wherein a width of the passage gradually increases towards a discharge port of the pump case.

Assignments (2)
CHANGE OF NAME Recorded Jan 28, 2009
From: MATSUSHITA ELECTRIC WORKS, LTD.
To: PANASONIC ELECTRIC WORKS CO., LTD.
Reel/Frame 022206/0574 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Apr 12, 2007
From: SAKAI, TOSHISUKE; UEDA, HIDETOSHI
To: MATSUSHITA ELECTRIC WORKS, LTD.
Reel/Frame 019242/0060 →