WO2018086931A1

WO2018086931A1 - Drain pump assembly for a washing machine and operating method

Info

Publication number: WO2018086931A1
Application number: PCT/EP2017/077750
Authority: WO
Inventors: Florin Horea CORCHES; Hakan Amac
Original assignee: Arcelik Anonim Sirketi
Priority date: 2016-11-08
Filing date: 2017-10-30
Publication date: 2018-05-17

Abstract

A drain pump assembly (1) for a washing machine (10) comprising: a casing (5) having a suction port (6) intended to be connected to the tub (3) of a washing machine (10) and a discharge port (7) intended to be connected to a drain duct (4) and comprising a filter housing (8), arranged between the suction port (6) and the discharge port (7); a filter (9) accommodated in the filter housing (8); and a drain pump (11) having an electric motor (12), connected to the casing (5) downstream of the filter housing (8) and activateable for draining water from the tub (3), through the suction port (6), and discharging it toward the drain duct (4), through the discharge port (7), wherein the drain pump assembly (1) further comprises a bypass (13) having an inlet opening (14) connected to the filter housing (8) and an outlet opening (15) connected to the casing (5) downstream of the filter housing and upstream of the discharge port (7).

Description

DRAIN PUMP ASSEMBLY FOR A WASHING MACHINE AND OPERATING METHOD

The present invention relates to a drain pump assembly for a laundry washing machine and to a washing machine comprising such drain pump assembly. The present invention further relates to a method of operating the washing machine having such drain pump assembly.

In the conventional washing machines or washing/drying machines a drain pump assembly is provided in order to drain the water from the tub to a drain duct at the end of a washing cycle. Generally the drain pump assembly comprises a casing having a suction port connected to the tub and a discharge port connected to the drain duct. The drain pump assembly further comprises a drain pump, usually a centrifugal pump, having an electric motor, connected to the casing and activateable for draining water from the tub, drawing it through the suction port, and discharging it toward the drain duct, through the discharge port.

The casing of the drain pump assembly comprises a filter housing, arranged between the suction port and the discharge port, wherein a filter is accommodated. The filter is aimed to collect the lint and foreign objects, such as for instance tissues, hairs, coins, needles, or buttons, present in the water drained from the tub, in order to avoid them to be discharged toward the drain duct together with the water.

The washing machines are generally programmed so as to stop the functioning of the drain pump when the filter reaches a predetermined level of clogging in order to protect its electric motor. The stopping of the drain pump sometimes can happen short after the start of the draining process. The water remained in the tub has therefore to be discharged manually by the user, in order to access and clean the filter. The manual discharging operation is time consuming and, due to the low position of the drain pump assembly, it is also tiresome for the user.

In order to obviate such problem, in recent years washing machines have been developed which try to avoid the need for a manual discharging operation of the tub when the filter is clogged.

An example of such a washing machine is given in the European patent n. EP 0807707 B1. The washing machine therein disclosed comprises a pressure switch controlling the level of the water in the wash tub and providing a continuous monitoring of the filter, so as to enable the user to be automatically alerted when the filter reaches such a degree of clogging as to actually require cleaning. In this manner the need for a manual discharging operation is prevented by alerting the user in advance, before the filter clogging requires the drain pump to be stopped.

The main drawback of the washing machine described in EP 0807707 B1 resides on the fact that the manual discharge operation can only be avoided if the user actually performs the filter cleaning once alerted by the washing machine, so that the correct functioning of the washing machine completely relies on the user’s diligence.

An objective of the present invention is to provide a drain pump assembly and a washing machine comprising such drain pump assembly which do not require the user to perform a manual discharging operation even in case of clogging of the filter.

A further object of the present invention is to provide a method of operating a washing machine that allows to easily and comfortably discharge the water remained in the tub in case of clogging of the filter.

These objectives have been achieved by the drain pump assembly as defined in claim 1, by the washing machine as defined in claim 8 and by the operating method as defined in claim 12. Further achievements have been attained by the subject-matters respectively defined in the dependent claims.

In the drain pump assembly for a washing machine of the present invention a bypass is provided for conveying the water toward the drain duct without forcing it to pass through the filter housing in case of clogging of the filter. The bypass on the casing of the drain pump assembly provides an alternative path for the residual water in the tub to be discharged toward the drain duct in case of filter clogging, so that no manual discharging operation is required.

In particular during normal operation of the drain pump assembly the filter is arranged in the filter housing of the casing in an operative position, in which it hinders the passage of water toward the bypass. In case of filter clogging the filter is movable to a discharging position, in which it opens the inlet opening to the bypass. To this aim, in an embodiment, the filter comprises a solid portion and a strainer portion which are intended to be placed in front of the inlet opening of the bypass respectively when the filter is in the operative position and in the discharging position.

In a preferred embodiment the filter is movable between the operative and the discharging positions by being rotated, advantageously manually by the user. To this aim in an embodiment the filter is provided with a handle and in a further embodiment indication means are provided on the filter and on the casing to show to the user the position of the filter in the casing.

The present invention comprises also a washing machine comprising the drain assembly as above specified. In an embodiment, the control unit of the washing machine is programmed to deactivate the motor of the drain pump assembly when clogging of the filter is detected and to allow its reactivation upon receiving a correspondent input by the user.

The present invention comprises also a method of operating the washing machine which envisages, upon detection of the clogging of the filter, the deactivation of the motor of the drain pump assembly, the warning of the user of the clogging of the filter, the movement of the filter from the operative position to the discharging position to open the inlet opening of the bypass and allow water to flow through it and the reactivation of the motor of the drain pump assembly, in order to allow the discharge of the residual water from the tub through the bypass toward the drain duct.

Additional advantages of the washing machine and of the operating method of the present invention will become more apparent with the detailed description of the embodiments with reference to the accompanying drawings in which:

Figure 1 is a back perspective view of a washing machine with a drain pump assembly according to the present invention, wherein part of the cabinet has been removed in order to better show the internal components of the washing machine.

Figure 2 is a perspective view of the drain pump assembly according to the present invention.

Figure 3 is an exploded view of the drain pump assembly of Figure 2.

Figure 4 is a perspective view of the filter of the drain pump assembly according to the present invention.

Figures 5 and 6 are cross-sectional views of the drain pump assembly according to the present invention showing the water flux when the filter is arranged respectively in an operative position and in a discharging position, wherein the filter has been removed to better show the water path in the casing.

The following numerals are assigned to different parts demonstrated in the drawings:

1) Drain pump assembly

2) Cabinet

3) Tub

4) Drain duct

5) Casing

6) Suction port

7) Discharge port

8) Filter housing

9) Filter

10) Laundry washing machine

11) Drain pump

12) Motor

13) Bypass

14) Inlet opening

15) Outlet opening

16) Solid position

17) Strainer portion

18) Through holes

19) Handle

20) Indication means

21) Visual marks

O) Operative position

D) Discharging position

X) Rotation axis

The present invention relates to a drain pump assembly 1 for a laundry washing machine 10, with or without the drying function, which washing machine 10 comprises a cabinet 2, a tub 3 arranged in the cabinet 2 and aimed to receive the water for performing a cleaning cycle, a drum (not illustrated) rotatably placed inside the tub 3 and aimed to receive the laundry to be cleaned and a drain duct 4 through which the water is drained from the tub 3 toward the outside of the washing machine 10.

The tub 3 is in particular aimed to receive clean water or water mixed together with detergent or similar products for the cleaning of the laundry depending on the different stages of the washing cycle. In the following, for the sake of simplicity, we will only refer to water, being obviously intended that the same could refer also to a water solution comprising detergent products, dirt from the laundry etc.

The drain pump assembly 1 comprises a casing 5 having a suction port 6 intended to be connected to the tub 3 of a washing machine 10 and a discharge port 7 intended to be connected to the drain duct 4 of a washing machine 10 and comprising a filter housing 8, arranged between the suction port 6 and the discharge port 7.

The drain pump assembly 1 further comprises a filter 9 accommodated in the filter housing 8 and a drain pump 11, in particular a centrifugal pump as illustrated in the attached drawings, having an electric motor 12, connected to the casing 5 downstream of the filter housing 8 and activateable for draining water from the tub 3 of a washing machine 10, through the suction port 6, and discharging it toward the drain duct 4, through the discharge port 7.

As it is known, the filter 9 is aimed to collect the lint and foreign objects, such as for instance tissues, hairs, coins, needles, or buttons, present in the water drained from the tub 3, in order to avoid them to be discharged toward the drain duct 4 together with the water.

According to the present invention, the drain pump assembly 1 further comprises a bypass 13 having an inlet opening 14 connected to the filter housing 8 of the casing 5 and an outlet opening 15 connected to the casing 5 downstream of the filter housing 8 and upstream of the discharge port 7. The filter 9 is movable with respect to the casing 5 between an operative position O, in which it blocks the passage of water through the inlet opening 14 of the bypass 13, and a discharging position D in which it allows passage of water through the inlet opening 14 of the bypass 13.

When the drain pump assembly 1 is mounted in a washing machine 10, in normal functioning condition, the filter 9 is arranged in the filter housing 8 in the operative position O, and the water drawn from the tub 3 by the action of the drain pump 11 flows through the filter housing 8, and hence the filter 9, and through the discharge port 7 toward the drain duct 4, as illustrated in attached Figure 5. In the operative position O the filter 9 obstructs the inlet opening 14 to the bypass 13, so that no water flows through the latter.

When the filter 9 is arranged in the discharging position D, as needed when the filter is clogged and the passage of water through the filter 9 is hindered by the clogging, the water is allowed to flow through the bypass 13, thus avoiding the clogging in the filter 9 and reaching the discharge port 7 to be discharged through the drain duct 4.

The presence of the bypass 13 in the drain pump assembly 1 according to the present invention allows to discharge the water drained from the tub 3 also when the filter 9 is clogged, so that no discharging operation to be performed manually by the user is required. By the simple rearrangement of the filter 9 with respect to the casing 5 the inlet opening 14 of the bypass 13, closed in normal working conditions, can be open, thus allowing the water to flow through the bypass 13 and to be in any case discharged.

According to an embodiment, the filter 9 comprises a solid portion 16, i.e. a portion not having any hole or passage, intended to be arranged at the inlet opening 14 of the bypass 13 when the filter 9 is in the operative position O for preventing the passage of water toward the bypass 13, and a strainer portion 17 provided with a plurality of through holes 18, intended to be arranged at the inlet opening 14 of the bypass 13 when the filter 9 is in the discharging position D for allowing the passage of water toward the bypass 13, as illustrated in the attached Figure 4. The solid portion 16 allows to effectively close the inlet opening 14 of the bypass 13, preventing water to enter in the latter, and the strainer portion 17 allows the water to reach the bypass 13, passing through the holes 18, while blocking possible foreign objects conveyed by it.

According to an embodiment illustrated in the attached figures, the filter 9 is movable between the operative position O and the discharging position D by rotating. In particular the filter 9 is movable between the operative position O and the discharging position D by being rotated around a rotation axis X, as illustrated in Figures 3 and 4. Advantageously the filter has substantially the shape of a solid of revolution, like a cylinder as in the embodiment illustrated in the attached figures, and the rotation axis X is the axis of revolution of its shape.

In an embodiment, the filter 9 comprises a handle 19 graspable by a user to manually move the filter 9 from the operative position O to the discharging position D and vice versa. The fact that the filter is manually movable between its working positions allows to maintain the drain pump assembly 1 and the washing machine 10 incorporating it constructionally rather simple.

According to an embodiment, the drain pump assembly 1 further comprises indication means 20 for indicating to a user the position of the filter 9 with respect to the casing 5, also when the filter is inserted in the filter housing 8. This allows the user to correctly arrange the filter 9 either in the operative position O or in the discharging position D, without the need to extract it from the filter housing 8, hence without incurring in the risk of provoking water leakages.

In a version of this embodiment, the indication means 20 comprises one or more visual marks 21 provided on the filter 9. In particular the visual mark or marks 21 can be incorporated on the handle 19 of the filter 9, as it is the case for the visual mark 21 in the shape of an arrow provided on the handle 19 of the filter 9 according to the embodiment illustrated in the attached figures. By seeing in which position the visual mark 21 of the filter 9 is arranged with respect to the casing 5, the user is allowed to understand in which correspondent position the filter 9 is arranged in the casing 5.

In a further version of this embodiment, the indication means 20 comprises a visual mark 21 on the filter 9 and at least two visual marks 21 on the casing 5. The visual mark 21 on the filter 9 is intended to be aligned with a correspondent visual mark 21 on the casing 5 for indicating to a user that the filter 9 is arranged either in the operative position O or in the discharging position D. In the attached figures, for instance, the visual mark 21 “I” on the casing 5 is used to indicate the operative position O of the filter 9 when the arrow constituting the visual mark 21 on the latter is aligned with it, while the visual mark 21 “II” on the casing 5 is used to indicate the discharging position D of the filter 9 when the arrow constituting the visual mark 21 on the latter is aligned with it. This allows the user to precisely know the position of the filter 9 with respect to the casing 5 and it is particularly relevant in case the position of the filter 9 is changed manually by the user.

It is an object of the present invention also a washing machine 10 comprising a drain pump assembly 1 as above described, having the suction port 6 connected to the tub 3 and the discharge port 7 connected to the drain duct 4.

As previously specified, the washing machine 10 according to the invention, thanks to the presence of the bypass 13 on the drain pump assembly 1, allows to easily and comfortably discharge the water remained in the tub 3 even in case of clogging of the filter 9, without requiring the user to discharge manually such residual water.

According to a preferred embodiment, the drain pump assembly 1 is designed so that the filter 9 is manually movable by the user between the operative position O and the discharging position D. According to a different embodiment, the drain pump assembly 1 is designed so that the filter 9 is automatically movable between the operative position O and the discharging position D.

In an embodiment, the washing machine 10 further comprises a control unit programmed to deactivate the motor 12 of the drain pump assembly 1 when clogging of the filter 9 is detected and to allow the reactivation of the motor 12 upon receiving a correspondent input b the user. More in detail the control unit is programmed to allow the reactivation of the motor 12 once the user for instance presses a start or restart button, after the filter 9 has been moved to the discharging position D.

Advantageously the washing machine 10 comprises warning means for warning the user that the filter 9 is clogged, like visual and/or acoustic warning means. Once the filter 9 has been positioned in the discharging position D, for instance manually by the user, the washing machine 10 can be restarted so that the residual water in the tub 3 can be expelled through the bypass 13 and the drain duct 4.

In a further embodiment, the control unit is programmed to again deactivate the motor 12 of the drain pump assembly 1 if the drain pump 11 does not correctly drain water through the bypass 13. This can happen for instance if the user restart the washing machine 10 without previously moving the filter to the discharging position D and ensures that no damages to the motor 12 are caused by a forced functioning of the latter.

In a different embodiment, the control unit of the washing machine 10 is again programmed to deactivate the motor 12 of the drain pump assembly 1 when clogging of the filter 9 is detected and the washing machine 10 further comprises a sensor for sensing the position of the filter 9 with respect to the casing 5. In this embodiment, the control unit is programmed to allow the reactivation of the motor 12 when the position of the filter 9 sensed by the sensor corresponds to the discharging position D. This embodiment allows a more accurate functioning of the washing machine 10, without relying solely on the user input. The washing machine 10 can be further provided in this embodiment with warning means to inform the user that the washing machine 10 can be restarted.

A further object of the present invention is a method of operating the washing machine 10 as above specified, comprising the procedural steps of activating the motor 12 of the drain pump assembly 1 with the filter 9 in the operative position O in order to drain water out of the tub 3. This can be done at the end of the washing cycle or after certain operational steps of the washing cycle, such as for instance a pre-washing step or a rinsing step. The method further comprises detecting clogging of the filter 9, deactivating the motor 12 of the drain pump assembly 1, in particular by means of the control unit, and warning the user of the clogging of the filter 9, advantageously by means of visual and/or acoustical warning means. According to the present invention, the method further comprises the steps of moving the filter 9 from the operative position O to the discharging position D and reactivating the motor 12 of the drain pump assembly 1. As previously specified, the step of moving the filter 9 from the operative position O to the discharging position D can be performed automatically by the washing machine 10 or, preferably, manually by the user.

In a version of the method, during the initial step of activating the motor 12, when the filter 9 is arranged in the operative position O, the visual mark 21 on the filter 9 is aligned with a first visual mark 21 on the casing 5, like for instance the visual mark 21 “I” according to the embodiment illustrated in the attached figures, and the step of moving the filter 9 from the operative position O to the discharging position D is performed by bringing the visual mark 21 on the filter 9 to be aligned with a second visual mark 21 on the casing 5, such as the visual mark 21 “II” according to the embodiment illustrated in the attached figures. In this way, the position of the filter 9 with respect to the casing 5 is accurately selected.

The drain pump assembly 1, the washing machine 10 and the method of operating the washing machine 10 according to the invention allow therefore to safely, easily and comfortably discharge the water from the tub 3 even in case of clogging of the filter 9, without requiring the user to perform the annoying manual discharging operation of the residual water in the tub 3 once the filter 9 has been detected to be clogged. After the residual water of the tub 3 has been discharged through the bypass 13, the user can easily remove the filter 9, without risks of water leakages, clean it by removing the items that provoked the clogging and reposition it in the casing 5 in the operative position O so that the drain pump assembly 1 can normally work in the next washing cycles.

Claims

A drain pump assembly (1) for a washing machine (10) comprising:

- a casing (5) having a suction port (6) intended to be connected to the tub (3) of a washing machine (10) and a discharge port (7) intended to be connected to a drain duct (4) and comprising a filter housing (8), arranged between the suction port (6) and the discharge port (7);

- a filter (9) accommodated in the filter housing (8);

- a drain pump (11) having an electric motor (12), connected to the casing (5) downstream of the filter housing (8) and activateable for draining water from the tub (3), through the suction port (6), and discharging it toward the drain duct (4), through the discharge port (7);

characterized in that it further comprises a bypass (13) having an inlet opening (14) connected to the filter housing (8) of the casing (5) and an outlet opening (15) connected to the casing (5) downstream of the filter housing (8) and upstream of the discharge port (7), the filter (9) being movable with respect to the casing (5) between an operative position (O), in which it blocks the passage of water through the inlet opening (14) of the bypass (13), and a discharging position (D) in which it allows passage of water through the inlet opening (14) of the bypass (13).
A drain pump assembly (1) as in Claim 1, characterized in that the filter (9) comprises a solid portion (16), intended to be arranged at the inlet opening (14) of the bypass (13) when the filter (9) is in the operative position (O) for preventing the passage of water toward the bypass (13), and a strainer portion (17) provided with a plurality of through holes (18), intended to be arranged at the inlet opening (14) of the bypass (13) when the filter (9) is in the discharging position (D) for allowing the passage of water toward the bypass (13).
A drain pump assembly (1) as in Claim 1 or 2, characterized in that the filter (9) is movable between the operative position (O) and the discharging position (D) by rotating.
A drain pump assembly (1) as in any of the previous claims, characterized in that the filter (9) comprises a handle (19) graspable by a user to manually move the filter (9) from the operative position (O) to the discharging position (D) and vice versa.
A drain pump assembly (1) as in any of the previous claims, characterized in that it comprises indication means (20) for indicating to a user the position of the filter (9) with respect to the casing (5).
A drain pump assembly (1) as in Claim 5, characterized in that the indication means (20) comprises at least a visual mark (21) provided on the filter (9).
A drain pump assembly (1) as in Claim 6, characterized in that the indication means (20) comprises a visual mark (21) on the filter (9) and at least two visual marks (21) on the casing (5), the visual mark (21) on the filter (9) being intended to be aligned with a correspondent visual mark (21) on the casing (5) for indicating to a user that the filter (9) is arranged in the operative position (O) or in the discharging position (D).
A washing machine (10) comprising:

- a cabinet (2);

- a tub (3) arranged in the cabinet (2) and aimed to receive the water for performing a cleaning cycle;

- a drum rotatably placed inside the tub (3) and aimed to receive the laundry to be cleaned;

- a drain duct (4) through which the water is drained from the tub (3) toward the outside of the washing machine (10) at the end of a washing cycle;

- a drain pump assembly (1) according to any of the previous claims, having the suction port (6) connected to the tub (3) and the discharge port (7) connected to the drain duct (4).
A washing machine (10) as in Claim 8, characterized in that it further comprises a control unit programmed to deactivate the motor (12) of the drain pump assembly (1) when clogging of the filter (9) is detected and to allow the reactivation of the motor (12) upon receiving a correspondent input by the user.
A washing machine (10) as in Claim 9, characterized in that the control unit is programmed to again deactivate the motor (12) of the drain pump assembly (1) if the drain pump (11) does not correctly drain water through the bypass (13).
A washing machine (10) as in Claim 8 or 9, characterized in that it further comprises a sensor for sensing the position of the filter (9) with respect to the casing (5) and a control unit programmed to deactivate the motor (12) of the drain pump assembly (1) when clogging of the filter (9) is detected and to allow the reactivation of the motor (12) when the position of the filter (9) sensed by the sensor correspond to the discharging position (D).
A method of operating a washing machine (10) according to any of the claims 8 to 10, comprising:

- activating the motor (12) of the drain pump assembly (1) with the filter (9) in the operative position (O) in order to drain water out of the tub (3);

- detecting clogging of the filter (9);

- deactivating the motor (12) of the drain pump assembly (1);

- warning the user of the clogging of the filter (9);

- moving the filter (9) from the operative position (O) to the discharging position (D); and

- reactivating the motor (12) of the drain pump assembly (1).
A method of operating a washing machine (10) as in Claim 12, wherein the drain pump assembly (1) of the washing machine (10) comprises a visual mark (21) on the filter (9) and at least two visual marks (21) on the casing (5), the visual mark (21) on the filter (9) being aligned with a first visual mark (21) on the casing (5) when the filter (9) is arranged in the operative position (O) and the step of moving the filter (9) from the operative position (O) to the discharging position (D) is performed by bringing the visual mark (21) on the filter (9) to be aligned with a second visual mark (21) on the casing (5).
A method of operating a washing machine (10) as in Claim 12 or 13, wherein the step of moving the filter (9) from the operative position (O) to the discharging position (D) is performed manually by a user.