ROTATING DRUM FILTER FOR A DISHWASHING MACHINE

• US 20110146730A1
• Filed: 12/21/2009
• Published: 06/23/2011
• Est. Priority Date: 12/21/2009
• Status: Active Grant

• Current Assignee: Whirlpool Corporation
• Original Assignee: Whirlpool Corporation
• Inventors: WELCH, RODNEY M.
• Granted Patent: US 8,746,261 B2
• Time in Patent Office: Days
• US Class Current: 134/104.4
• CPC Class Codes: A47L 15/4206 Tubular filters
• CPC Class Codes: A47L 15/4208 Arrangements to prevent clogging of the filters, e.g. self-cleaning

Abstract

A dishwashing machine includes a housing in fluid communication with a washing chamber and a cylindrical filter positioned in the housing that is operable to rotate about a longitudinal axis. A flow diverter is positioned within the inner chamber at a location between the housing and the rotary filter and is spaced apart from the rotary filter so as to create a gap. During rotation of the filter, the angular velocity of fluid advanced through the gap is increased relative to the angular velocity of the fluid prior to entering the gap.

Claims

1. A dishwashing machine comprising:

a spray arm,

a sump positioned below the spray arm for collecting fluid and soil particles,

a housing in fluid communication with the sump and the spray arm, the housing having an inner chamber,

a cylindrical porous sheet positioned in the inner chamber and operable to rotate about a longitudinal axis, the porous sheet having an outer surface, and

a flow diverter positioned in the inner chamber, the flow diverter having a tip spaced apart from the outer surface of the porous sheet so as to define a gap,

wherein during rotation of the porous sheet, the angular velocity of fluid advanced through the gap is increased relative to the angular velocity of the fluid prior to entering the gap.

2. The dishwashing machine of claim 1, further comprising:

a wash pump including an impeller coupled to the porous sheet, the impeller being operable to rotate about the axis,

wherein (i) the cylindrical porous sheet encloses a hollow interior, and (ii) the rotation of the impeller advances fluid through the porous sheet into the hollow interior.

3. The dishwashing machine of claim 2, wherein the wash pump has an inlet port positioned within the hollow interior and an outlet port fluidly coupled to the spray arm.

4. The dishwashing machine of claim 2, further comprising a second flow diverter positioned within the hollow interior, the second flow diverter having an outer surface spaced apart from an inner surface of the porous sheet.

5. The dishwashing machine of claim 2, wherein pores of the porous sheet are sized such that soil particles accumulate on the outer surface of the porous sheet as fluid advances through the porous sheet into the hollow interior.

6. The dishwashing machine of claim 5, wherein soil particles accumulated on the outer surface of the porous sheet are removed by fluid passing through the gap during rotation of the porous sheet.

7. The dishwashing machine of claim 1, wherein the porous sheet is a sheet of chemically etched metal.

8. The dishwashing machine of claim 1, further comprising a drain pump coupled to the housing, wherein the drain pump is operable to remove fluid from the inner chamber.

9. The dishwashing machine of claim 1, wherein the impeller and the sheet are rotated about the axis at 3200 rpm.

10. The dishwashing machine of claim 1, wherein the gap is sized such that the angular velocity of the fluid is at least sixteen percent greater than the angular velocity of the fluid prior to entering the gap.

11. The dishwashing machine of claim 1, wherein:

the housing has an inlet fluidly coupled to the sump, and

the inlet has a porous screen positioned therein such that fluid advancing from the sump passes through the porous screen.

12. The dishwashing machine of claim 1, wherein:

(i) the housing has an inner surface facing the inner chamber, and

(ii) a number of ribs extend away from the inner surface into the inner chamber.

13. A dishwashing machine comprising:

a washing chamber having a bottom surface,

a sump positioned in the bottom surface of the washing chamber,

a housing fluidly coupled to the sump, the housing having an inner chamber defined therein,

a cylindrical drum positioned in the inner chamber, the drum being operable to rotate about an imaginary axis,

a filter sheet extending from a first end of the drum to a second end of the drum, the filter sheet defining a hollow interior,

a first flow diverter positioned in the inner chamber at a location between the housing and the cylindrical drum, and

a second flow diverter positioned opposite the first flow diverter at a location within the hollow interior of the drum, the second flow diverter is spaced apart from the first flow diverter so as to create a gap,

wherein the angular velocity of fluid advanced through the gap is increased relative to fluid bypassing the gap during rotation of the drum.

14. The dishwashing machine of claim 13, wherein the first flow diverter extends from the first end of the drum to the second end of the drum.

15. The dishwashing machine of claim 13, further comprising a beam positioned in the hollow interior, wherein the second flow diverter is coupled to a portion of the beam.

16. The dishwashing machine of claim 13, further comprising a bearing secured to the housing and rotatably coupled to the second end of the drum.

17. The dishwashing machine of claim 13, further comprising a wash pump in fluid communication with the inner chamber, the wash pump being operable to draw fluid through the filter sheet into the hollow interior.

18. The dishwashing machine of claim 17, wherein:

the filter sheet has a plurality of pores extending from an outer surface to an inner surface, and

the pores of the filter sheet are sized such that fluid advances therethrough to the hollow interior and soil particles accumulate on the outer surface of the filter sheet.

19. The dishwashing machine of claim 18, wherein soil particles accumulated on the outer surface of the filter sheet are removed as the outer surface of the filter sheet passes through the gap between the first flow diverter and the second flow diverter.

20. A recirculation pump assembly for a dishwasher, comprising:

a housing having an inlet port configured to be fluidly coupled to a sump of a dishwasher and an outlet port configured to be fluidly coupled to a spray arm of the dishwasher,

an impeller positioned at a first end of the housing between the inlet port and the outlet port, the impeller being operable to rotate about an axis such that fluid is advanced from the inlet port to the outlet port,

a rotary filter coupled at a first end to the impeller and at a second end to the bearing, the rotary filter having a hollow interior defined therein, and

a flow diverter positioned within the inner chamber at a location between the housing and the rotary filter, the flow diverter being spaced apart from the rotary filter so as to create a gap,

wherein the angular velocity of fluid advanced through the gap is increased relative to fluid bypassing the gap during rotation of the rotary filter.