Washing machine pump

Claim 2

A reversible pump for a laundry appliance having an internal impeller cavity, an inlet and a main outlet communicating separately with said impeller cavity, an impeller rotatable within said cavity, said impeller including means to pump said water from said inlet to said outlet with positive displacement action when driven in a first direction during a pump out mode, a secondary outlet communicating with said impeller cavity, said impeller including means to pump water from said inlet through said secondary outlet port when driven in an opposite direction in a recirculation mode, and bypass means between said inlet means and said auxiliary outlet means to control pressure in said main outlet when said impeller is rotating in said recirculation mode.

Claim 3

A pump as set forth in claim 1 wherein said positive displacement means includes means to normally produce a substantial vacuum in said main outlet when said impeller is driven in said recirculation mode.

Claim 4

A pump as set forth in claim 2 wherein said impeller includes a plurality of circumferentially spaced blades, said blades each having a substantially flat outer face, said faces having a tangential orientation.

Claim 5

A pump as set forth in claim 3 wherein each of said blade faces are oriented at an angle of approximately 50* to a radial line extending from the axis of the impeller to a radially outermost portion of each respective blade.

Claim 6

A reversible pump for a laundry appliance comprising a housing having an internal impeller cavity, an inlet and a main outlet communicating separately with said impeller cavity, an auxiliary outlet communicating with said cavity, an impeller rotatable within said cavity, said impeller including means to pump water from said inlet to said main outlet when driven in a pump out mode and to pump water from said inlet through said auxiliary outlet when driven in an opposite recirculation mode, said housing including an end wall, said auxiliary outlet being arranged on said housing adjacent the circumference of said impeller, said inlet being integrally formed in said end wall and extending radially across said end wall in a direction substantially towards said auxiliary outlet, and bypass means between said inlet and said auxiliary outlet to control pressure in said main outlet during operation in said recirculation mode.

Claim 7

A reversible pump for a laundry appliance comprising a housing having an internal impeller cavity, an inlet and a main outlet communicating separately with said impeller cavity, an auxiliary outlet communicating with said cavity, an impeller rotatable within said cavity, said impeller including means to pump water from said inlet to said main outlet when driven in a pump out mode and to pump water from said inlet through said auxiliary outlet when driven in an opposite recirculation mode, said housing including an end wall, said auxiliary outlet being arranged on said housing adjacent the circumference of said impeller, said inlet being integrally formed in said end wall and extending radially across said end wall in a direction substantially towards said auxiliary outlet, and bypass means between said inlet and said auxiliary outlet to control pressure in said main outlet during operation in said recirculation mode.

Claim 8

A pump as set forth in claim 5 wherein said inlet is in open communication with said cavity substantially from the center of said impeller to the circumference of said impeller.

Claim 9

A pump as set forth in claim 6 wherein said bypass means includes an aperture in a wall of said housing adjacent a housing end wall opposite said first mentioned end wall.

Claim 10

A pump as set forth in claim 7 wherein said aperture comprises an elongated slot extending lengthwise along the circumference of said impeller.

Claim 11

A pump as set forth in claim 7 wherein said inlet includes a wall portion radially outward of said aperture, said wall portion forming a section of a recirculating flow receiving recess external of said cavity, said wall portion being adapted to be perforated to provide an alternate flow path within the housing when an external recirculation circuIt is not provided.

Claim 12

A reversible pump for a laundry appliance comprising a housing having an impeller cavity, said cavity being defined by a circumferential curved housing wall and opposed housing end walls, a rotatable impeller in said cavity, an inlet communicating with the impeller cavity through a plane defined by one of said end walls, a main outlet communicating with said cavity tangentially to said curved wall, and a recirculation outlet communicating with said cavity through an aperture in said curved wall, said aperture being axially displaced from said one end wall and being adjacent the opposite wall.

Claim 13

A reversible pump for a laundry appliance comprising a housing having an impeller cavity, said cavity being defined by a circumferential curved housing wall and opposed housing end walls, a rotatable impeller in said cavity, an inlet communicating with the impeller cavity through a plane defined by one of said end walls, a main outlet communicating with said cavity tangentially to said curved wall, and a recirculation outlet communicating with said cavity through an aperture in said curved wall, said aperture being axially displaced from said one end wall and being adjacent the opposite wall.

Claim 14

A pump as set forth in claim 10 wherein said inlet comprises an integral channel in said one end wall, said channel extending radially from the rotational axis of said impeller in angular alignment with said auxiliary outlet, a wall portion within said housing forming both a portion of said inlet channel and a zone in direct communication with said recirculation outlet whereby said wall portion may be perforated where external recirculation is not desired.

Claim 15

A bi-directional pump for a laundry appliance comprising a housing having an internal impeller cavity, an inlet and an outlet communicating separately with said impeller cavity, a rotatable impeller in said cavity, said impeller including means for pumping water from said inlet to said outlet when driven in one direction, a recess external of said cavity for receiving recirculation flow when said impeller is driven in a direction opposite to said first direction, said recess communicating with said cavity through an aperture in a wall forming said cavity adjacent the periphery of said impeller.

Claim 16

A bi-directional pump for a laundry appliance comprising a housing having an internal impeller cavity, an inlet and an outlet communicating separately with said impeller cavity, a rotatable impeller in said cavity, said impeller including means for pumping water from said inlet to said outlet when driven in one direction, a recess external of said cavity for receiving recirculation flow when said impeller is driven in a direction opposite to said first direction, said recess communicating with said cavity through an aperture in a wall forming said cavity adjacent the periphery of said impeller.

Claim 17

A pump as set forth in claim 12 wherein said recess is formed by at least two walls, one of said walls forming a portion of said inlet, the other of said walls forming a portion of a recirculation outlet, said one wall being adapted to be perforated to establish internal recirculation flow in said housing when external recirculation is not provided.

Claim 18

A reversible pump for a laundry appliance comprising a plastic housing of generally uniform wall thickness, said housing including an internal volute impeller cavity, an inlet communicating with the center of the cavity, a main outlet and an auxiliary outlet each communicating with the cavity at its periphery, an integrally molded impeller, said impeller including a plurality of flat tengentially oriented blades, an impeller hub including means for mounting the impeller directly on a motor shaft, said impeller including means to pump water from said inlet to said main outlet when driven in one direction and from said inlet to said auxiliary outlet when driven in the opposite direction.

Claim 19

A reversible pump for a laundry appliance comprising a plastic housing of generally uniform wall thickness, said housing including an internal volute impeller cavity, an inlet communicating with the center of the cavity, a main outlet and an auxiliary outlet each communicating with the cavity at its periphery, an integrally molded impeller, said impeller including a plurality of flat tengentially oriented blades, an impeller hub including means for mounting the impeller directly on a motor shaft, said impeller including means to pump water from said inlet to said main outlet when driven in one direction and from said inlet to said auxiliary outlet when driven in the opposite direction.

Claim 20

A reversible pump for a laundry appliance, comprising a housing having an internal impeller cavity, said impeller cavity being defined by a pair of axially spaced end walls and a circumferential wall, said circumferential wall having a generally circular major portion and a volute minor portion, a main outlet in said volute wall portion and a recirculation outlet adjacent the circular major portion and angularly spaced from said main outlet, an inlet channel integrally formed in one of said end walls, said inlet channel extending in open communication from the center of said impeller cavity along a radial direction in line with said recirculation outlet, said recirculation outlet communicating with said impeller cavity through a recess external of said cavity, an aperture in said circumferential wall adjacent the other of said end walls providing communication between said cavity and said recess, said inlet channel and said recess having a common wall adapted to be perforated to provide a recirculating flow path internal of the housing when external recirculation flow from said recirculation outlet is not provided, an impeller rotatable in said cavity in a first direction to pump fluid from said inlet through said main outlet, and in an opposite direction to pump Fluid from said inlet through said aperture, said impeller including a plurality of substantially flat, tangentially oriented blades, a clearance between said impeller and said circumferential wall providing a bypass circuit between said aperture and said inlet to regulate the pressure at said main outlet when said impeller is driven in said recirculation direction.

Claim 21

A reversible pump for a laundry appliance, comprising a housing having an internal impeller cavity, said impeller cavity being defined by a pair of axially spaced end walls and a circumferential wall, said circumferential wall having a generally circular major portion and a volute minor portion, a main outlet in said volute wall portion and a recirculation outlet adjacent the circular major portion and angularly spaced from said main outlet, an inlet channel integrally formed in one of said end walls, said inlet channel extending in open communication from the center of said impeller cavity along a radial direction in line with said recirculation outlet, said recirculation outlet communicating with said impeller cavity through a recess external of said cavity, an aperture in said circumferential wall adjacent the other of said end walls providing communication between said cavity and said recess, said inlet channel and said recess having a common wall adapted to be perforated to provide a recirculating flow path internal of the housing when external recirculation flow from said recirculation outlet is not provided, an impeller rotatable in said cavity in a first direction to pump fluid from said inlet through said main outlet, and in an opposite direction to pump Fluid from said inlet through said aperture, said impeller including a plurality of substantially flat, tangentially oriented blades, a clearance between said impeller and said circumferential wall providing a bypass circuit between said aperture and said inlet to regulate the pressure at said main outlet when said impeller is driven in said recirculation direction.