EP2816945B1

EP2816945B1 - Double delivery pump and washing machine provided thereof

Info

Publication number: EP2816945B1
Application number: EP13707092.6A
Authority: EP
Inventors: Alessio Chericoni; Riccardo ORLANDI
Original assignee: Premark FEG LLC
Current assignee: Premark FEG LLC
Priority date: 2012-02-24
Filing date: 2013-02-21
Publication date: 2021-04-28
Anticipated expiration: 2033-02-21
Also published as: WO2013126481A8; WO2013126481A1; ES2877824T3; EP2816945A1; ITTO20120165A1

Description

TECHNICAL FIELD

The present invention relates to a double delivery pump specifically designed for equipping a professional dishwashing machine, of the type in which the washing chamber is defined by a tank and a hood, vertically movable with respect to the tank for allowing the dishes to be placed onto and removed from the tank, and where the washing chamber is provided with an upper sprinkler arm and a lower sprinkler arm for a washing liquid, fed by said pump. The invention further relates to a dishwashing machine provided with such a double delivery pump.

BACKGROUND ART

A dishwashing machine of the above-mentioned type is known, for example, from US-A-4536043 . In this machine, the upper and lower sprinkler arms are fed in common by a single pump having a single delivery conduit which is branch connected to a first and a second feeding conduit for the upper and lower sprinkler arms, respectively.
A double delivery pump for dishwashing machines is also known from EP-A-1004266 , having two separate delivery conduits served by a single pump impeller and arranged oriented at 180° with respect to each other, to which the feeding conduits of the sprinkler arms are separately connected in a direct manner.
While both the above-described solutions are relatively satisfactory, they are not free from drawbacks. The solution according to US-A-4536043 implies large overall dimensions and considerable load losses along the feeding pipings of the sprinkler arms, which thus result in high energy consumption. The solution according to EP-A-1004266 may also pose large overall dimension problems as it forces the designer to pass the feeding pipes of the sprinkler arms on two different sides of the dishwashing machine or to make undesired bends. Moreover, in both solutions, the pump yield is relatively low, undesired noise may be triggered, and in the case of EP-A-1004266 , accurately controlling the pressure head available at the ends of the two pump delivery conduits is not always possible.

DISCLOSURE OF INVENTION

The object of the present invention is to provide a pump for a dishwashing machine for professional use of the above-described type which overcomes the above-mentioned drawbacks, being also reliable, easy to be implemented and assembled, and small in size.
It is also an object of the invention to provide a dishwashing machine provided with such a pump.
A double delivery pump for a dishwashing machine for professional use is therefore provided according to the invention, as defined in claim 1.
Moreover, a dishwashing machine is provided according to claim 7.
The pump according to the invention is intended for a dishwashing machine comprising a washing chamber delimited by a vertically movable hood, two sprinkler arms, the upper arm and the lower arm respectively, arranged within the washing chamber, and a pump for feeding in use a washing fluid to the sprinkler arms through first and second pipings, respectively.
The pump comprises a single pump body provided with a single centrifugal impeller therein and externally provided with a first and a second delivery conduit, which project so as to protrude from the pump body, outside the same.
According to the invention, the first and second delivery conduits are arranged so as to form an acute angle therebetween and project from the pump body at the same angular position, thus intersecting each other according to said acute angle at respective connecting root portions thereof to the pump body.
The pump also includes an electric motor and a supporting plate, and the pump body is cup-shaped and fluid-tightly connected, on the side of an internal cavity thereof, to the supporting plate carried by the electric motor for the impeller by means of a plurality of screws or bolts arranged as a crown about the rotation axis of the impeller; and at the intersection between the first and second delivery conduits, a peripheral rim of the pump body being provided with a fitting and angular locking projecting part.
The acute angle formed by the intersection of the first and second delivery conduits may be between 30° and 60° and is preferably about 43°. Moreover, the first and second delivery conduits may have the same diameter and the same passage section.
Thereby, both the upper and the lower sprinkler arm can be separately fed with a single pump having a single impeller, without having the considerable load losses associated with the use of pumps with a single delivery which is then branch connected (i.e. connected as a branch) to the two sprinkler arms. Moreover, the overall dimensions are greatly reduced and the fitting of the pump/feeding tube assembly for the sprinkler arms of a dishwasher provided with such a pump is simplified; but especially, having two delivery conduits that protrude at an angle to each other from a single angular point or position of the pump body totally surprisingly allows the noise usually associated with double delivery pumps to be eliminated, the energy consumptions of the pump to be further reduced due to the high yields obtained, and a same controlled pressure head value to be obtained at the ends of both delivery conduits.

BRIEF DESCRIPTION OF THE DRAWINGS

Further objects and advantages of the invention will become apparent from the following description of a non-limiting embodiment thereof, provided by way of mere example and with reference to the figures of the accompanying drawings, in which:

figure 1 schematically shows a perspective three-quarter back view - partially cutaway - of a professional dishwashing machine of the type with vertically movable hood provided according to the invention, having parts removed for simplicity;
figure 2 shows a perspective view on enlarged scale of a double delivery pump according to the invention, suitable for equipping the dishwashing machine in figure 1;
figure 3 shows an internal detail on enlarged scale of the dishwashing machine in figure 1 with the pump of figure 2 in operating configuration;
figure 4 shows a perspective view on enlarged scale of an internal detail of a pump body of the pump in figure 1; and
figure 5 shows in a schematic way and out of scale a view cutaway according to a trace plane V-V of the detail in figure 4.

With particular reference to figure 1, reference numeral 1 indicates as a whole a dishwashing machine, to which reference will be made hereinafter simply as "dishwasher 1" for shortness, comprising a support
casing 2, a tank 3 (figure 1) carried by casing 2 and a known hood 5, carried by casing 2 in a known manner, so as to vertically slide over tank 3, and which hood delimits in use, along with tank 3, a washing chamber 4 of dishwasher 1, inside which two or more sprinkler arms, an upper arm 6 and two concentric lower arms 7, respectively, are positioned in a known manner; dishwasher 1 finally also comprises, in addition to casing 2 with tank 3, hood 5 and arms 6, 7, a pump 8 for feeding in use a washing fluid (e.g. water) to the sprinkler arms 6, 7 through a first piping 9 and a second piping 10, respectively, arranged along with pump 8 within the casing 2 of the dishwasher machine 1.
With reference to figures 2 to 5, the double delivery pump 8 comprises a single pump body 11 provided with a single centrifugal impeller 12 therein (figure 5) and externally provided with a first 13 and a second 14 delivery conduit, which project so as to protrude from the pump body 11, outside the same, tangentially with respect to a profile P shown by a lateral surface 15 of the pump body 11 on a cross section plane perpendicular to a rotation axis A of impeller 12, which in figure 5 coincides with the sheet plane.
According to the invention, the first and second delivery conduits 13 and 14 are arranged so as to form an acute angle α therebetween (figure 2) and project from the pump body 11 at the same angular position, thus intersecting each other according to said acute angle α at respective connecting root portions 16, 17 thereof to the pump body 11 according to said acute angle.
According to an aspect of the invention, the acute angle α formed by the intersection of the delivery conduits 13 and 14 is between 30° and 60°, and preferably is about 43°, except for the common molding tolerances, body 11 being preferably obtained as a single piece with conduits 13 and 14 by molding a synthetic plastic material.
Moreover, according to a further aspect of the invention, conduits 13 and 14 have the same diameter and the same passage section, as clearly seen in figure 5.
By virtue of the particular geometry described, the same pressure head is present in use at respective terminal ends 18 and 19 of conduits 13 and 14, facing the side opposite to the pump body 11, for example equal to 0.6 BAR, which in use, according to the invention, remains substantially constant at both ends 18 and 19.
In order to allow conduits 13 and 14 to be oriented at an acute angle but making them protrude from the pump body 11 at a same angular position, profile P shown by the lateral surface 15 of the pump body 11 in a cross section plane perpendicular to the rotation axis A of the impeller (figure 5) is a substantially spiral profile, seen in plan view, which may originate from the same axis A.
In particular, the pump body 11 has a circular seat 20 therein for impeller 12 and a delivery spiral 21 radially outside seat 20 for impeller 12; a passage section S of delivery spiral 21 gradually widens in the radial direction as it moves away from the rotation axis A of the impeller according to a spiral profile on said section plane.
According to a further aspect of the invention, the root portions 16, 17 of conduits 13, 14 join together, geometrically penetrating into each other, so as to define therein a single common inlet mouth 22 for the connection to the delivery spiral 21.
The common inlet mouth 22 for the first and second delivery conduits 13 and 14 has a passage section which is substantially identical to that of a terminal end 23 of the delivery spiral 21 to which the common inlet mouth 22 is immediately adjacent.
Moreover, the pump body 11 (figure 4) is cup-shaped as it is delimited by a bottom wall 24 and a lateral wall 25 which define an internal cavity 26 therebetween, and is fluid-tightly connected, on the side of its internal cavity 26, to a supporting plate 27 (figures 2 and 3) carried by an electric motor 28 for impeller 12 by means of a plurality of screws or bolts 29 arranged as a crown about axis A; at the intersection between conduits 13 and 14, a peripheral rim 30 of the pump body 11 is further provided with a fitting and angular locking projecting part 31 towards plate 27 (figure 4) .
When the described pump 8 is part of dishwasher 1, i.e. with pump 8 being fitted within casing 2, the first and second delivery conduits 13, 14 are directly connected to the first piping 9 and to the second piping 10, respectively, separate from each other, as is well shown in figure 3.
In particular, the first and second pipings 9, 10 are connected to the first and second delivery conduits 13 and 14 of pump 8 by means of corresponding terminal ends 32, 33 thereof curved at a right angle and which are arranged so as to form an acute angle therebetween similar to angle α; moreover, the pump body 11 is shaped and fitted within casing 2 so that conduits 13 and 14 are arranged substantially horizontal, while the rotation axis A of the impeller 12 of pump 8 is arranged so as to be substantially vertical.

Claims

A double delivery pump (8) for a dishwashing machine (1), in particular for a professional dishwashing machine provided with a washing chamber (4) delimited by a vertically movable hood (5) and provided with two sprinkler arms (6, 7), upper and lower arms respectively, within the washing chamber, to which the pump feeds in use a washing fluid through a first piping (9) and a second piping (10), respectively; the pump comprising a single pump body (11) provided with a single centrifugal impeller (12) therein and externally provided with a first (13) and a second (14) delivery conduit, which project so as to protrude from the pump body, outside the same, and are arranged so as to form an acute angle (α) therebetween and project from the pump body at the same angular position, thus intersecting each other according to said acute angle (α), at respective connecting root portions (16, 17) thereof to the pump body,
characterized in that the pump (8) also includes an electric motor (28) and a supporting plate (27), and the pump body (11) being cup-shaped and fluid-tightly connected, on the side of an internal cavity (26) thereof, to the supporting plate (27) carried by the electric motor (28) for the impeller by means of a plurality of screws or bolts (29) arranged as a crown about the rotation axis (A) of the impeller; and at the intersection between the first and second delivery conduits (13, 14), a peripheral rim (30) of the pump body being provided with a fitting and angular locking projecting part (31).
A double delivery pump according to claim 1, characterized in that the acute angle (α) formed by the intersection of the first and second delivery conduits (13, 14) is between 30° and 60° and is preferably equal to about 43°.
A double delivery pump according to claim 1 or 2, characterized in that the first and second delivery conduits (13, 14) have the same diameter and the same passage section.
A double delivery pump according to one of the preceding claims, characterized in that the same pressure head is present in use at corresponding terminal ends (18, 19) of the first and second delivery conduits (13, 14), facing the side opposite to the pump body (11).
A double delivery pump according to one of the preceding claims, characterized in that said profile (P) shown by the lateral surface of the pump body on a cross section plane perpendicular to the rotation axis (A) of the impeller is a substantially spiral profile; the pump body (11) having a circular seat (20) for the impeller therein and a delivery spiral (21) arranged radially outside the impeller seat, a passage section of the delivery spiral gradually widens in the radial direction as it moves away from the rotation axis (A) of the impeller according to a spiral profile on said section plane; the root portions (16, 17) of the first and second conduits joining together so as to define therein a single common inlet mouth (22) for the connection to the delivery spiral (21).
A double delivery pump according to claim 5, characterized in that said common inlet mouth (22) for the first and second delivery conduits has a passage section which is substantially identical to that of a terminal end (23) of the delivery spiral to which the common inlet mouth (22) of the first and second conduits is immediately adjacent.
A dishwashing machine (1) comprising a washing chamber (4) delimited by a vertically movable hood (5), sprinkler arms (6, 7), upper and lower arms respectively, arranged within the washing chamber (4), and a pump (8) for feeding in use a washing fluid to said sprinkler arms through first (9) and second (10) pipings, respectively, arranged along with the pump within a casing (2) of the dishwashing machine supporting the hood (5); characterized in that the pump (8) is made according to any one of claims 1 to 6; and in that the first and second delivery conduits (13, 14) are directly connected to the first and second pipings (9, 10), respectively, independently of each other.
A dishwashing machine (1) according to claim 7, characterized in that said first and second pipings (9, 10) are connected to said first and second delivery conduits (13, 14) of the pump by means of corresponding terminal ends (32, 33) thereof curved at a right angle and which are arranged so as to form an acute angle therebetween; the pump body (11) being shaped and fitted within the casing (2) so that said first and second delivery conduits (13, 14) of the pump are arranged substantially horizontal, while the rotation axis (A) of the pump impeller is arranged so as to be substantially vertical.