EP3649911A1

EP3649911A1 - Drive device for a flow diverter

Info

Publication number: EP3649911A1
Application number: EP19208266.7A
Authority: EP
Inventors: Ernesto GROSSI; Giovanni Cerizza
Original assignee: Robertshaw SRL
Current assignee: Robertshaw Italy Srl
Priority date: 2018-11-12
Filing date: 2019-11-11
Publication date: 2020-05-13
Also published as: IT201800010254A1

Abstract

Drive device for a flow diverter, comprising at least one entrance shaft (27), connected to a motor (28) able to make said entrance shaft (27) rotate, and at least one exit shaft (29) connectable, during use, to a selector element (16) of a flow diverter (15), wherein said entrance shaft (27) and said exit shaft (29) are aligned along an axis of rotation (R) and the rotation motion of said entrance shaft (27) is transferred to said exit shaft (29) by means of an epicyclic reduction unit (31) comprising at least one central gear (32) associated with said entrance shaft (27), at least a plurality of planet gears (33), cooperating with said central gear (32) and with an internal toothed crown (34), and at least one planet-carrying member (35) able to support said planet gears (33) and to be connected to said exit shaft (29).

Description

FIELD OF THE INVENTION

The present invention concerns a drive device for a flow diverter, used for example in a household appliance such as a dishwasher, a dryer or other.
The present invention also concerns a household appliance, such as a dishwasher, a dryer or suchlike, provided with at least one flow diverter, suitable to direct a flow of water, or other fluid, at least toward a first pipe or toward a second pipe, and provided with the drive device for the flow diverter.

BACKGROUND OF THE INVENTION

As is known, flow diverters or flow diverter valves are used in some household appliances, such as for example dishwashers or dryers.
In dishwashers, for example, the flow diverter is used to direct the water at exit from the wash pump toward an upper rack or toward a lower rack of the dishwasher, and normally comprises a perforated disk or plate which acts as a selector element and which, rotating, directs the jet of water alternately to an upper impeller normally located above the upper rack or to a lower impeller normally located above the lower rack.
The flow diverter can also control the water pressure between the upper impeller and the lower impeller, allowing for example a higher pressure during the rinsing steps.
Fig. 1, for example, shows a known tub 10 for a dishwasher. This dishwasher is of the type which provides a distribution of the flow of water coming from the tub 10 toward at least a pair of pipes 11 and 12, for example a first pipe 11 which takes the washing water toward an impeller associated with an upper rack of the dishwasher, and a second pipe 12 which takes the water toward an impeller associated with a lower rack. These pipes 11 and 12 are made in a conveyor 14 positioned in the tub 10. The conveyor 14 comprises a cylindrical element 21 able to be housed in a seating 22 of the tub 10, for example by means of screwing, bayonet attachment or suchlike.
The water can be directed toward one or the other of the pipes 11 and 12 by means of a flow diverter 15 comprising a selector element 16, for example a disk provided with an exit hole 17 for the water to exit toward one or the other of the pipes 11 and 12.
The water is fed to the tub 10 and then to the conveyor 14 by means of at least one suitable feed pipe 26.
The selector element 16 comprises a seating 20 into which one end of an exit shaft 18 of a drive device 19 for the flow diverter 15 can be inserted.
The drive device 19 substantially has the function of rotating the selector element 16 so that the hole 17 is positioned in correspondence with the pipe 11 or the pipe 12.
The drive device 19 comprises a motor 24, which has an entrance shaft which is connected to the exit shaft 18 by means of a series of gears. The entrance shaft is directed substantially along an axis A and is therefore in an offset and misaligned position with respect to the position of the exit shaft 18, which will be connected to the selector element 16.
The entrance shaft and the exit shaft 18 have to be connected by means of a series of motion transmission gears which are contained inside a casing 25 of the drive device 19. The casing 25 is attached to the lower body of the tub 10 in a known manner.
As can be observed in fig. 1, the current drive device 19, due above all to the misalignment of the entrance shaft directed along the axis A and of the exit shaft 18, has a certain bulk, it reduces the maneuvering space under the tub 10 and is also rather noisy, since transmission gears are used that are of a considerable size in relation to the use of the drive device 19.
Moreover, normally, due to this misalignment and to the mode of motion transmission from the entrance shaft to the exit shaft 18, the distribution of forces is not optimal and the exit shaft 18 is able to withstand limited loads, in terms of torque.
In modern dishwashers, it is desirable to increase the water pressure in order to obtain a better cleaning and this could damage the flow diverter 15 driven by the known drive device 19, since the exit shaft 18 withstands limited torque.
Furthermore, normally, in order to replace the motor 24 of the current flow diverter 15, it is also necessary to empty the water from the tub 10, since it is necessary to remove the whole casing 25 and therefore also the transmission gears and the exit shaft 18 to proceed with the replacement.
Furthermore, the size and type of motor 24 are necessarily linked to the size and shape of the casing 25.
In addition, given the nature of transmission gears and their disposition, the current drive device 19 is often subject to early phenomena of wear and loss of efficiency.
Other limitations and disadvantages of conventional solutions and technologies will be clear to a person of skill after reading the remaining part of the present description with reference to the drawings and the description of the embodiments that follow, although it is clear that the description of the state of the art connected to the present description must not be considered an admission that what is described here is already known from the state of the prior art.
There is therefore the need to perfect a drive device for a flow diverter that can overcome at least one of the disadvantages of the state of the art.
One purpose of the present invention is to provide a drive device for a flow diverter which has compact sizes, reduced bulk, is efficient and easily assembled.
Another purpose of the present invention is to provide a drive device for a flow diverter in which the exit shaft can withstand a torque that is significantly higher than the torque that the exit shaft of a traditional drive device can withstand.
Another purpose of the present invention is to provide a drive device for a flow diverter that has high durability and is provided with motion transmission elements that are subject to a limited wear compared to known motion transmission elements, thanks also to their small size and their reciprocal disposition.
Another purpose of the present invention is to provide an drive device for a flow diverter which is modular and whose motor, in the event the flow diverter is used in a dishwasher, can be mounted and removed from the rest of the drive device in a simple and immediate manner, avoiding for example having to proceed with emptying the water contained in the tub of the dishwasher.
Another purpose of the present invention is to provide a drive device for a flow diverter which, thanks to its compactness, allows a high maneuverability in correspondence with the zone of the household appliance in which it is installed, and which can also possibly provide the use of different types of motor.
Another purpose of the invention is a household appliance comprising a flow diverter driven by the present drive device.
The Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.

SUMMARY OF THE INVENTION

The present invention is set forth and characterized in the independent claims, while the dependent claims describe other characteristics of the invention or variants to the main inventive idea.
In accordance with the above purposes, one purpose of the invention is a drive device for a flow diverter, comprising at least one entrance shaft, connected to a motor able to make the entrance shaft rotate, and at least one exit shaft connectable, during use, to a selector element of a flow diverter.
According to one aspect of the invention, the entrance shaft and the exit shaft are aligned along an axis of rotation and the rotation motion of the entrance shaft is transferred to the exit shaft by means of an epicyclic reduction unit comprising at least one central gear associated with the entrance shaft, at least a plurality of planet gears, cooperating with the central gear and with an internal toothed crown, and at least one planet-carrying member able to support the planet gears and to be connected to the exit shaft.
Advantageously, the present drive device for a flow diverter, thanks to the use of an epicyclic reduction unit, allows to obtain high reduction ratios between the entrance shaft and the exit shaft, high compactness, low noise and high couple or torque values on the exit shaft, also proving to be much more efficient and resistant to wear compared to the drive devices of known flow diverters.
According to another aspect of the invention, the planet-carrying member can comprise a central gear cooperating with another plurality of planet gears located between the planet-carrying member and the exit shaft, wherein the exit shaft is associated with another planet-carrying member supporting the other plurality of planet gears, so as to achieve a double reduction stage.
In this double reduction stage, the planet gears can have the same sizes and can be disposed in equal number on the corresponding planet-carrying members.
Each of these planet gears can be in contact with the planet-carrying member by means of annular contact surfaces opposite to the corresponding planet gear.
In some embodiments, the planet-carrying member can be formed by two distinct annular elements, wherein at least one of the annular elements is provided with a plurality of pins suitable to be inserted in a plurality of seatings made on the other annular element and wherein each of the planet gears is provided with a through hole through which one of the pins passes.
The motor can be attached, removably and by means of corresponding attachment elements, in sequence to the epicyclic reduction unit, so that it can be connected or disconnected to/from the drive device, leaving the drive device in position.
In some embodiments, the motor can be attached to a bottom wall of the internal toothed crown of the epicyclic reduction unit.
The motor can comprise a flange for attachment to the bottom wall, wherein the flange is provided on the periphery with notches suitable to be positioned in appropriate teeth of the bottom wall.
The drive device can comprise a lid to close the epicyclic reduction unit, provided with a through hole from which the exit shaft protrudes.
Another purpose of the invention is a household appliance, comprising at least one flow diverter suitable to direct a flow of water, or other fluid, at least toward a first pipe or toward a second pipe and a drive device for the flow diverter.
These and other aspects, characteristics and advantages of the present disclosure will be better understood with reference to the following description, drawings and attached claims. The drawings, which are integrated and form part of the present description, show some embodiments of the present invention, and together with the description, are intended to describe the principles of the disclosure.
The various aspects and characteristics described in the present description can be applied individually where possible. These individual aspects, for example aspects and characteristics present in the description or in the attached dependent claims, can be the object of divisional applications.
It is understood that any aspect or characteristic that is discovered, during the patenting process, to be already known, shall not be claimed and shall be the object of a disclaimer.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other characteristics of the present invention will become apparent from the following description of some embodiments, given as a non-restrictive example with reference to the attached drawings wherein:

fig. 1 is a three-dimensional view of a drive device for a flow diverter known in the field;
fig. 2 is a three-dimensional and exploded view of a drive device for a flow diverter according to the invention;
fig. 3 is a three-dimensional section view of the present drive device for a flow diverter;
fig. 4 is a three-dimensional view of the present drive device for a flow diverter in assembled configuration;
fig. 5 is a three-dimensional view of the present drive device for a flow diverter able to be associated with a tub of a dishwasher;
fig. 6 is a three-dimensional view of the present drive device for a flow diverter assembled to the tub of fig. 5.

To facilitate comprehension, the same reference numbers have been used, where possible, to identify identical common elements in the drawings. It is understood that elements and characteristics of one embodiment can conveniently be incorporated into other embodiments without further clarifications.

DETAILED DESCRIPTION OF SOME EMBODIMENTS

We will now refer in detail to the various embodiments of the present invention, of which one or more examples are shown in the attached drawings. Each example is supplied by way of illustration of the invention and shall not be understood as a limitation thereof. For example, the characteristics shown or described insomuch as they are part of one embodiment can be adopted on, or in association with, other embodiments to produce another embodiment. It is understood that the present invention shall include all such modifications and variants.
Before describing these embodiments, we must also clarify that the present description is not limited in its application to details of the construction and disposition of the components as described in the following description using the attached drawings. The present description can provide other embodiments and can be obtained or executed in various other ways. We must also clarify that the phraseology and terminology used here is for the purposes of description only, and cannot be considered as limitative.
With reference to the attached drawings, see for example fig. 2 and fig. 3, a drive device 30 according to the invention comprises at least one entrance shaft 27 connected to a motor 28 able to make the entrance shaft 27 rotate, and at least one exit shaft 29 connectable, during use, to a selector element 16 of a flow diverter 15, visible in fig. 5.
The entrance shaft 27 and the exit shaft 29 are aligned along the axis of rotation R and the rotation motion of the entrance shaft 27 is transferred to the exit shaft 29 by means of an epicyclic reduction unit 31.
This epicyclic reduction unit 31 comprises at least one central gear 32, or solar gear, associated with the entrance shaft 27 and at least a plurality of planet gears 33 cooperating with the central gear 32 and with an internal toothed crown 34. This internal toothed crown 34 is fixed.
The planet gears 33 can be supported by at least one planet-carrying member 35 which can be connected directly or indirectly to the exit shaft 29, in this way, the epicyclic reduction unit 31 effectively guarantees at least one reduction stage.
To increase the reduction ratio of the epicyclic reduction unit 31 it is possible, as shown in fig. 2 and fig. 3, to provide a double reduction stage, in order to obtain high reduction ratios between the entrance shaft 27 and the exit shaft 29, even 1/100, which allow to obtain a high couple on the exit shaft 29.
To achieve this double reduction stage, the epicyclic reduction unit 31 comprises another plurality of planet gears 36 located between the planet-carrying member 35 supporting the planet gears 33 and the exit shaft 29, associated with another planet-carrying member 37 supporting the other plurality of planet gears 36.
The planet-carrying member 35 is therefore in this case provided with its own central gear 38 able to cooperate with the planet gears 36 of the other planet-carrying member 37, to which the exit shaft 29 is connected.
As mentioned, in any case if it is desired to obtain a single reduction stage, the planet-carrying member 35 could be directly associated with the exit shaft 29, instead of providing the other central gear 38.
In the case of a double reduction stage and therefore ultimately using two series of planet gears 33 and 36, preferably the planet gears 33 and 36 have the same sizes and are disposed in equal numbers on the corresponding planet-carrying members 35 and 37.
Each of these planet-carrying members 35 and 37 is formed by two distinct annular elements, respectively the annular elements 40 and 41 for the planet-carrying member 35 and the annular elements 42 and 43 for the planet-carrying member 37. The planet-carrying members 35 and 37 are therefore formed by separable annular elements 40, 41 and 42, 43 which allow both the correct support of the planet gears 33 and 36, and also their possible removal.
For example, it is possible to provide that in each pair of annular elements 40, 41 and 42, 43, an annular element, for example the annular element 41 or 43, is provided with a pin 45 suitable to be firmly inserted in a seating 46 made in the other annular element, for example the annular element 40 or 42. Each of the planet gears 33, 36 has a through hole 47 through which the pin 45 passes.
Each of the planet gears 33 and 36, see in particular fig. 3, comprises two annular contact surfaces 44 and 44' for contact with the corresponding planet-carrying member 35 and 37, so that an optimal distribution of the contact forces in play is guaranteed. The annular contact surfaces 44 and 44' are opposite with respect to the corresponding planet gear 33 and 36.
Preferably, the motor 28 is a synchronous electric motor and comprises connectors 39 for electric power supply.
The motor 28 is removably attached by means of attachment elements 48 such as screws or suchlike, in sequence to the epicyclic reduction unit 31, so that it can be easily mounted and removed from the drive device 30.
In particular, the motor 28 is attached to a bottom wall 49 of the internal toothed crown 34 of the epicyclic reduction unit 31, see in particular fig. 4.
The bottom wall 49 comprises a through hole 23 suitable to allow at least the passage of the entrance shaft 27 and of the central gear 32, see fig. 3.
The motor 28 can comprise a flange 50 to achieve the removable attachment to the bottom wall 49.
The flange 50 can be provided on the periphery with appropriate notches 56 suitable to be positioned in corresponding teeth 13 of the bottom wall 49 of the internal toothed crown 34, so as to guarantee the correct positioning of the motor 28 with respect to the epicyclic reduction unit 31.
The epicyclic reduction unit 31 is closed by means of a removable lid 51. The lid 51 comprises a through hole 52 from which the exit shaft 29 protrudes. The lid 51 can be provided with an annular ridge 53 on the lateral wall, for example rounded, suitable to be inserted, substantially in a snap-in manner, in an annular groove 54 made on the epicyclic reduction unit 31, in particular on the external wall of the internal toothed crown 34.
The exit shaft 29, as can be observed, can be provided with a faceted end 55 suitable to be inserted in the corresponding seating 20 of the selector element 16 of the flow diverter 15 and to transmit the rotary motion to the selector element 16.
Fig. 5 and fig. 6 show the tub 10 of a household appliance, for example a dishwasher, which needs a flow diverter 15. This household appliance could also be a dryer or other.
The drive device 30 is removably attached to a lower part of the tub 10 by means of any suitable positioning element whatsoever, for example the positioning elements 57, with which it is possible to associate any type of attachment element whatsoever, removable with the tub 10.
As can be understood, the use of a drive device 30 for the flow diverter 15 with a compact and also symmetrical shape allows to obtain a high maneuvering space under the tub 10.
Moreover, advantageously, the motor 28 can be easily removed from the rest of the drive device 30 simply by removing the attachment elements 48, thus avoiding having to remove all the rest of the drive device 30 which can be left in position. Consequently, advantageously, it is possible to proceed with dismantling the motor 28 of the drive device 30 without having to empty the tub 10. Furthermore, as can be intuitively understood by observing fig. 5 and fig. 6, the drive device 30 could provide the installation of a motor different from the motor 28 shown, thanks to the maneuvering and positioning spaces made under the tub 10 and thanks to the fact that the drive device 30 is, as seen, substantially modular, therefore the motor 28 can be easily separated from the epicyclic reduction unit 31.
The present drive device 30 therefore proves to be extremely reliable, compact and easy to handle, and also allows to obtain a high couple on the exit shaft 29 and a high reduction ratio thanks to the use of the epicyclic reduction unit 31, which also allows to keep the entrance shaft 27 and the exit shaft 29 aligned.
Therefore, the present drive device 30 can be effectively used in any household appliance whatsoever comprising a flow diverter 15 suitable to direct a flow of water, or other fluid, toward a first pipe 11 or toward a second pipe 12, see for example fig. 6.
It is clear that modifications and/or additions of parts may be made to the drive device for a flow diverter as described heretofore, without departing from the field and scope of the present invention.
It is also clear that, although the present invention has been described with reference to some specific examples, a person of skill in the art shall certainly be able to achieve many other equivalent forms of drive device for a flow diverter, having the characteristics as set forth in the claims and hence all coming within the field of protection defined thereby.
In the following claims, the sole purpose of the references in brackets is to facilitate reading: they must not be considered as restrictive factors with regard to the field of protection claimed in the specific claims.

Claims

Drive device for a flow diverter, comprising at least one entrance shaft (27), connected to a motor (28) able to make said entrance shaft (27) rotate, and at least one exit shaft (29) connectable, during use, to a selector element (16) of a flow diverter (15), characterized in that said entrance shaft (27) and said exit shaft (29) are aligned along an axis of rotation (R) and the rotation motion of said entrance shaft (27) is transferred to said exit shaft (29) by means of an epicyclic reduction unit (31) comprising at least one central gear (32) associated with said entrance shaft (27), at least a plurality of planet gears (33), cooperating with said central gear (32) and with an internal toothed crown (34), and at least one planet-carrying member (35) able to support said planet gears (33) and to be connected to said exit shaft (29).
Drive device as in claim 1, characterized in that said planet-carrying member (35) comprises a central gear (38) cooperating with another plurality of planet gears (36) located between said planet-carrying member (35) and said exit shaft (29), said exit shaft (29) being associated with another planet-carrying member (37) supporting said other plurality of planet gears (36).
Drive device as in claim 2, characterized in that said planet gears (33, 36) are the same size and are disposed in equal number on the corresponding planet-carrying members (35, 37).
Drive device as in any claim hereinbefore, characterized in that each of said planet gears (33) is in contact with the planet-carrying member (35) by means of annular contact surfaces (44, 44') opposite to the corresponding planet gear (33).
Drive device as in any claim hereinbefore, characterized in that said planet-carrying member (35) is formed by two distinct annular elements (40, 41), at least one of said annular elements (41) being provided with a plurality of pins (45) suitable to be firmly inserted in corresponding seatings (46) made on the other annular element (40) and each of the planet gears (33) being provided with a through hole (47) through which one of said pins (45) passes.
Drive device as in any claim hereinbefore, characterized in that said motor (28) is attached, removably and by means of corresponding attachment elements (48), in sequence to said epicyclic reduction unit (31).
Drive device as in claim 6, characterized in that said motor (28) is attached to a bottom wall (49) of the internal toothed crown (34) of said epicyclic reduction unit (31).
Drive device as in claim 7, characterized in that said motor (28) comprises a flange (50) for attachment to said bottom wall (49), said flange (50) being provided on the periphery with notches (56) suitable to be positioned in appropriate teeth (13) of said bottom wall (49).
Drive device as in any claim hereinbefore, characterized in that it comprises a lid (51) to close the epicyclic reduction unit (31), provided with a through hole (52) from which said exit shaft (29) protrudes.
Household appliance, comprising at least one flow diverter (15) suitable to direct a flow of water, or other fluid, at least toward a first pipe (11) or toward a second pipe (12), characterized in that it comprises a drive device (30) of said flow diverter (15) as in any claim hereinbefore.