Pump and liquid supplying apparatus

• US 20070243086A1
• Filed: 04/12/2007
• Published: 10/18/2007
• Est. Priority Date: 04/18/2006
• Status: Active Grant

• Current Assignee: Panasonic Electric Works Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Asahi Matsushita Electric Works Ltd. (Panasonic Holdings Corporation)
• Inventors: Sakai, Toshisuke, Ueda, Hidetoshi
• Granted Patent: US 7,891,958 B2
• Time in Patent Office: Days
• US Class Current: 417/423.100
• CPC Class Codes: F04D 13/0606 Canned motor pumps
• CPC Class Codes: F04D 13/16 with storage reservoirs
• CPC Class Codes: F04D 29/586 specially adapted for liquid pumps

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

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 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, 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.

2. The pump according to claim 1, wherein the reflux passages are disposed adjacent to a bearing provided at a central part of the impeller.

3. The pump according to claim 1, wherein 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 liquid flow direction of the impeller.

5. The pump according to claim 1, wherein the extra passage is disposed at an angle of 90°

or greater with respect to a liquid flow direction of the impeller.

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. A liquid supply apparatus having the pump according to claim 1.