GB2049406A

GB2049406A - Improvements in dish washing machines

Info

Publication number: GB2049406A
Application number: GB8010853A
Authority: GB
Original assignee: Industrie Zanussi SpA
Current assignee: Industrie Zanussi SpA
Priority date: 1979-05-21
Filing date: 1980-04-01
Publication date: 1980-12-31
Also published as: ES490137A0; DE3018526C2; AR223039A1; DE3018526A1; IT1166231B; FR2457096B1; GB2049406B; IT7945715A0; AU5856380A; FR2457096A1; AU530283B2; ES8103959A1

Abstract

In a dish washing machine comprising well (5), circulating pump (9) and discharge pump (10), the well has a vertical transverse wall (6) on which are mounted both the motors (7, 8) of the pumps with their respective shafts passing through said wall, and the pumps are housed within the well with parts (45, 46) of their housings being integral with said wall. <IMAGE>

Description

SPECIFICATION Improvements in dish washing machines The present invention relates to dish washing machines and in particular to the construction and mounting of the operating devices of such machines.

Dish washing machines are known which are provided with circulating and discharge pumps with coaxial rotors which are actuated by a single motor with a vertical axis. This design is disadvantageous primarily because, even when one of the rotors is housed within the tub of the machine, the vertical bulk of the unit is excessive, with a consequent reduction in the load capacity in respect of crockery in the tub and the necessity for the bottom of the tub to be of a greatly flattened configuration. This second limitation involves loading the machine with water over a relatively large area and thus with greater differences in the volume of water with which the machine is loaded.

Also known are dish washing machines having pumps with horizontal axes, which are fixed below the tub and which are connected by means of suitable ducts to a reservoir or well for collecting the washing liquid, which is disposed on the bottom of the tub. This design also suffers from serious disadvantages because it is found difficult to have access to the rotors for any action thereon, particularly when the dish washer is encased in a kitchen unit. In addition, the amount of liquid required for the washing operation is increased, in view of the greater extent of the hydraulic circuit of the machine, this being in contrast to the increasingly strong requirement to reduce the consumption of water and electrical power required for heating the water.

Finally, dish washers are known which are provided with a single horizontal axis pump for circulating and discharging the washing liquid, with a lower half-shell which is provided integrally with the collecting reservoir or well of the machine. In this case however it is necessary to provide complicated valve means for switching the flow of liquid from the washing circuit to the discharge circuit; in addition, with such a design, the residual amount of water which is not discharged in every phase is noticeably greater.

According to the present invention, there is provided a dish washer comprising: a tub; a well for collecting the washing liquid and secured to the lower part of the tub; and a circulating pump and a discharge pump which are separate from another and which both have a horizontal axis; wherein the well is shaped with a vertical transverse wall on which are mounted respective motors associated with the pumps and connected thereto by respective shafts passing through said wall, said pumps both being housed within the well and having respective shells partly provided integrally with said wall.

As will be apparent from the description below of an embodiment of the invention, it is possible to obtain the following advantages: a reduction in the vertical bulk of the operating devices of the machine; a reduction in the consumption of washing liquid and the differences in the volume of liquid in loadihg the machine; the possibility of mounting and testing the operating devices in the collection well before the well is fixed to the tub; the possibility of gaining access from the interior of the tub to the rotors of the circulating and discharge pumps; and a reduction in the hydraulic seals and thus in the dangers of losses from the machine.

The invention will be further described by way of non-limiting example with reference to the accompanying drawings wherein: Figure 1 is a plan view from above of the collecting well of a dish washer according to one embodiment of the invention; Figure 2 is a view taken in section along line Il-Il of the well of Figure 1; and Figures 3 and 4 are respective sectional views taken along lines Ill-Ill and IV-IV of the well of Figure 1.

Referring to the drawings, the collecting well of the dish washer comprises a single portion 5 of plastics material which is of circular outline and which is provided with a transverse wall 6 which extends vertically for a certain distance from the bottom of the well.

The wall 6 separates the interior of the well from an outside space (which is included within the circular outline), capable of housing the respective electric motors 7 and Sofa circulating pump 9 and a discharge pump 10 which are separate from each other and which both have a horizontal axis. The shafts of the motors 7 and 8 are passed sealingly through the transverse wall 6 and the respective pumps 9 and 10 are disposed within the well 5. In particular, a lower portion of the shell of both the pumps is provided integrally with the wall 6.

Referring now in particular to Figure 3, the circulating pump 9 is provided with an intake duct 11 which is removable and which is curved towards the bottom of the well. The duct 11 is mounted, by means of a groove configuration, with a seal of labyrinthine type, between the edge of the lower portion 45 of the shell which is integrated with the wall 6, and the edge of an upper shell portion 12 which, however, is removable and fixed by means of vertical screws 13. For greater ease of dismantling of the pump 9, the intake duct 11 is integral with a sector 14 forming a further portion of the shell.

The motor shaft 15 of the circulating pump 9 passes through an opening 16 in the wall 6; keyed thereon are the rotor 17 and a ring 18 which seals with a co-operating sliding surface 19. The sliding surface member 19 is fixed to the casing of the motor 7 (rather than to the shell of the pump, as is normally the case), with an interposed sealing means 20. This arrangement therefore frees the seal from errors in mounting the motor on the well. The sealing means 20 is of a cross-section shaped as shown in Figure 3 and comprises an enlarged peripheral ring portion 21 capable of sealing between the casing of the motor 7 (which is suitably provided with at least one projection 22) and the edge of the opening 16 in the wall 6.The ring portion 21 advantageously forms a damping means in respect of the motor 7 which at its rear is supported, with an interposed resilient member 23, by a vertical bracket 24 co-operating with a horizontal connecting strut 25, both of which are secured to screws 26 and 27 which are fixed vertically to the well 5.

The bracket 24 and the strut 25 are limited to holding the motor 7 pressed against the wall 6 of the well, while the actual support for the motor 7 is provided by the interaction as between the projection 22 on the motor casing, the sealing means 20 and the edge of the opening 16.

The simplicity and rationality in respect of assembly (combined with an optimum damping action) in respect of the motor 7 and the associated circulating pump 9 will be apparent. It is possible easily to gain access to the rotor 17 from the interior of the tub of the machine, by removing the upper portion 12 of the shell and the duct 11,the latter being removed after rotation through about 1800 about the axis of the pump in orderto disengage the sector 14 from the rotor 17. The motor 7 can also be easily removed by removing the bracket 24 and the strut 25.

With particular reference now to Figure 4, the motor shaft 28 of the discharge pump 10 passes through an opening 29 in the transverse wall 6, with a rotor 30 being keyed thereon.

The discharge pump 10 has an upper shell portion 31 which is removable and which is fixed by a groove configuration, with a sealing means of labyrinth type, to the respective shell portion 46 which is provided integrally with the wall 6 of the well. The removable portion 31 is provided with an extension portion 32 which extends towards the bottom of the well and which is capable of defining with a depression in the bottom of the well, an intake passage which communicates with the remaining space in the well only by way of a filter 62.

The edge of the opening 29 in the transverse wall 6 forms a housing for carrying a sealing means 33 (which is of the cross-sectional shape shown in Figure 4), capable of sealing to the motor shaft 28 of the discharge pump and between the casing of the motor 8 (suitably provided with an annular projection 34) and the wall 6. The latter is provided with a further housing 35 which is coaxial with the opening 29 and into which is inserted one end of the casing of the motor 8. The motor 8 is supported solely by the housing 35 against which it is held in position by a shaped bracket 36, which is preferably resilient and whose opposite ends co-operate with respective seats 37 and 38 provided on the wall 6 of the well and in which it is engaged with a vertical movement.

In order to make the fixing of the motor 8 more secure, the bracket 36 may be secured to the well 5 by means of a vertical screw 39 which is easily accessible for any removal of the motor 8. The rotor 30 is also easily accessible from the interior of the tub of the machine, by removing the upper shell portion 31.

It should be noted that the rotors of the circulating pump 9 and the discharge pump 10 are accessible and can possibly be dismantled without the necessi ty also to remove the respective motors, by acting directly from the interior of the washing tub.

The advantages of the dish washer according to the invention will be evident from the foregoing description, the dish washer being provided with a one-piece collecting well in which are integrated the main operating devices of the machine (the shell of the pumps, separate intake ducts, air trap 40 of the pressurestat, intake aperture 41 for the inflow of water, and outlet 42 of the discharge pump 10).

Respective outlets 43 and 44 of the circulating pump 9 to the rotary spray means (not shown) are provided integrally with the upper portion 12 of the shell of the pump 9. Such compactness, combined with the relative dispositions of the various components (including the electric motors 7 and 8) provides for a substantial reduction in the vertical bulk of the operating members, thus permitting an increase in the height of the washing tub. The wastage of water is also reduced (by virtue of the limited extent of the hydraulic circuits of the pumps) and the rational mounting of the various operating members makes it possible, in addition to the other advantages referred to hereinbefore, to pre-assemble such members, while also permitting a reduction in the hydraulic seals and a greater degree of simplicity in manufacture on an industrial scale and intervention for technical assistance.

In addition, the resulting altimetric configuration of the well 5 (and the bottom of the tub of the machine) provides for a static head for the water (that is to say, with the circulating pump 9 inoperative) over a surface area which is substantially reduced with respect to the inside surface area of the bottom of the tub (for example in a ratio of 1 :2). This provides for correct priming of the circulating pump with a smaller amount of water and a reduction in the differences in the volume of water which is taken into the tub, equal to altimetrictolerance of the device for controlling the water load.

Obviously, the above-described dish washer may undergo any modifications which are thought to be appropriate, without thereby departing from the scope of the invention. For example, the well 5 may be advantageously strengthened by integrating the vertical wall 6 with a rib 61 (see Figure 2) which ensures structural rigidity of the assembly.

Claims

1. A dish washer comprising: a tub; a well for collecting the washing liquid and secured to the lower part of the tub; and a circulating pump and a discharge pump which are separate from one another and which both have a horizontal axis; wherein the well is shaped with a vertical transverse wall on which are mounted respective motors associated with the pumps and connected thereto by respective shafts passing through said wall, said pumps both being housed within the well and having respective shells partly provided integrally with said wall.

2. A dish washer according to claim 1 wherein the circulating pump is provided with a removable intake duct which extends towards the bottom of the well, said duct being mounted by a groove configur ation between the edge of the lower portion of the shell which is integrated in said wall, and the edge of an upper removable portion of said shell and being provided with a sector forming a further portion of said shell.

3. A dish washer according to claim 2 wherein a seal for the motor shaft of the circulating pump comprises a portion rotating with said shaft and a fixed portion, one òf the portions of the seal being fixed only on the casing of the motor with an interposed sealing means.

4. A dish washer according to claim 3 wherein said sealing means integrally comprises an enlarged peripheral ring portion capable qf sealing between the casing of the motor and the well, said ring portion also forming a damping memberforthe fixing of the motor in said wall of the well.

5. A dish washer according to claim 4 wherein the motor of the circulating pump is supported at the rear by a vertical bracket co-operating with a horizontal connecting strut in such a way as to hold the motor pressed against said wall of the well, said bracket and said connecting strut being connected to screws which are fixed vertically in the well.

6. A dish washer according to any one of the preceding claims, wherein the discharge pump comprises a removable shell portion which is associated with a groove configuration with the respective portion which is provided integrally in said wall of said well, said removable portion being provided with an extension portion which is directed towards the bottom of the well and which is capable of defining therewith an intake channel communicating with the remaining space in the well only by way of a filter.

7. A dish washer according to any one of the preceding claims wherein provided in said wall of the well are a first housing for receiving a seal capable of sealing on the shaft of the motor of the discharge pump and between the casing of said motor and said wall, and a second housing into which is inserted an end of the casing of said motor, which is held in axial position by a bracket cooperating with respective seats provided in said wall.

8. A dish washer according to any one of the preceding claims, wherein the vertical wall is integrated with a rib provided integrally with the well and capable of ensuring structural rigidity thereof.

9. A dish washer constructed and arranged substantially as described with reference to and as illustrated in the accompanying drawings.