DESCRIPTION

[0001] The present invention relates to a pump group for a vehicle cooling system .

[0002] In the course of the description, the term "vehicle" means any means of locomotion which comprises an internal combustion engine and also hybrid powered vehicles , without any limitation related to type or si ze , i . e . a motor vehicle or an articulated vehicle .

[0003] In other words , the present invention relates to the automotive sector and in detail to the thermal management system of a vehicle .

[0004] In particular, said cooling system is speci fic for cooling an "operating group" of the vehicle .

[0005] In particular, in the present description, "operating group" means a component or a group of components speci fic for the execution of a speci fic operation necessary for the motion of the vehicle . In a preferred embodiment , the "operating group" comprises the engine group, for example of the endothermic or electric type .

[0006] In further embodiments , the "operating group" comprises other components of the vehicle , both of the mechanical type , such as a transmission assembly, and of the electrical type , such as a "battery assembly" included in the vehicle .

[0007] In the prior art, many embodiments of pump groups for a cooling system of an operating group are known which di f fer from each other in terms of si ze and type of actuation .

[0008] Speci fically, the pump group obj ect of the present invention falls within this context , having an electrictype drive . In other words , the pump group obj ect of the present invention comprises at least one electric motor which commands the rotary movement of the impeller included therein, thus commanding the movement of the cooling liquid which flows in the cooling system to which the pump group is fluidically connectable . A plurality of technical solutions of pump groups are known comprising an electric drive in which the main problem of this type of pump groups has been faced, i . e . the need to ef fectively cool the electric motor of the pump group and its related components .

[0009] In particular, embodiments of pump groups are known in which the cooling liquid present in the chamber where the impeller is housed is used to also cool the electric motor and its related components . Even more speci fically, the interest in exploiting the cooling liquid for cooling the rotor included therein is known in the prior art .

[0010] Furthermore , embodiments of pump groups are known in which the problem linked to the cooling of the stator is also addressed .

[0011] In some embodiments , the pump groups have been designed to favor the cooling of the stator towards the external environment .

[0012] In other embodiments , however, a certain quantity of oil has been provided in the stator chamber with the aim of cooling the chamber in which it is housed by convection . An example showing this pump group solution is for example shown in document W02020/ 07562 in the name of the Applicant .

[0013] On the other hand, these embodiments have an ef fective cooling of the rotor and/or of the stator, but fail to ef fectively cool the other portions of the pump group .

[0014] The obj ect of the present invention is therefore to provide a pump group for a cooling system for an operating group of a vehicle that has an ef fective cooling of the entire electronic command components , obviating the problems mentioned above .

[0015] Such obj ect is achieved by a pump group according to claim 1 . The dependent claims relate to preferred embodiment variants having further advantageous aspects .

[0016] The obj ect of the present invention is described in detail hereafter, with the aid of the accompanying drawings , in which :

[0017] - Figure 1 illustrates a longitudinal sectional view of a pump group according to the present invention, according to a possible embodiment , shown in a vertical operating position;

[0018] - Figure 2 shows a longitudinal sectional view of a pump group according to the present invention, according to a possible embodiment , shown in a hori zontal operating position;

[0019] - Figure 3 illustrates a longitudinal sectional view of a pump group according to the present invention, according to a possible embodiment , shown in an inclined position .

[0020] In the above tables , the reference numeral 1 denotes , in its entirety, a pump group for a cooling system for an operating group of a vehicle , preferably for cooling the engine group, for example of the internal combustion type .

[0021] The pump group 1 obj ect of the present invention extends mainly in length with respect to an axi s X-X .

[0022] The pump group 1 obj ect of the present invention comprises an impeller 2 rotatable with respect to said axis X-X . In other words , said impeller 2 has a center of rotation which lies on said axis X-X .

[0023] Preferably, the impeller 2 is of the radial type being specially shaped to perform a suction action of the cooling liquid preferably in the axial direction and to perform a thrusting action preferably in the radial direction . In particular, the "cooling liquid" is a water-based liquid, for example a solution comprising water and glycol , which circulates in the cooling system of the vehicle to which the pump group 1 obj ect of the present invention is fluidically connectable .

[0024] According to the present invention, moreover, the pump group 1 comprises a shaft 3 which extends in length along the axis X-X . Preferably, said shaft 3 comprises a rotating end 32 on which the impeller 2 is integrally mounted .

[0025] According to the present invention, the pump group 1 comprises an electric motor 4 suitable for driving the shaft 3 in rotation .

[0026] The electric motor 4 comprises a rotor 41 and a stator 42 . According to a preferred embodiment , the rotor 41 and the stator 42 are arranged concentrically with respect to the axis X-X .

[0027] According to the present invention, the rotor 41 is integrally mounted, for example keyed, on said shaft 3 : the rotation of the shaft 3 and in turn of the impeller 2 corresponds to the electronically commandled rotation of the rotor 41 . The stator 42 axially and circumferentially surrounds the rotor 41 . In particular, the stator 42 comprises a plurality of stator coils forming a stator .

[0028] According to the present invention, the pump group 1 comprises an electronic command board 5 operatively connected to the motor shaft 3 and suitable for commanding the rotation thereof about the axis X-X . In other words , the electronic board 5 commands the operation of the electric motor 4 , hence the rotation of the shaft 3 and in turn of the impeller 2 .

[0029] According to the present invention, the pump group 1 comprises a pump body 6 that extends parallel and mainly around the axis X-X . The pump body 6 is suitable for containing the various operating components of the pump group 1 and is suitable for being fluidically connectable to the vehicle cooling system .

[0030] According to the present invention, the pump body 6 comprises along the axis X-X :

[0031] - a first casing 61 in which the impeller 2 is housed in an impeller chamber 610 ;

[0032] - a second casing 62 in which the electric motor 4 is housed in a motor chamber 620 ; in particular, the motor chamber 620 houses the rotor 41 and the stator 42 ;

[0033] - a third casing 63 in which the command board 5 is housed in a command chamber 630 .

[0034] According to the present invention, the second casing 62 comprises an intermediate tubular wall 625 which extends parallel to the axis X-X positioned between the rotor 41 and the stator 42 .

[0035] Said intermediate tubular wall 625 divides a rotor chamber 621 and a stator chamber 622 in the second casing 62 . In other words , the motor chamber 620 is divided into a rotor chamber 621 and a stator chamber 622 . Preferably, the rotor chamber 621 and the stator chamber 622 are mutually f luid-tightly separated .

[0036] According to a preferred embodiment , said first casing 61 , and in particular the impeller chamber 610 included therein, is fluidly connected with the ducts of the cooling system in which the cooling liquid flows .

[0037] According to a preferred embodiment , the first casing 61 and the second casing 62 are separated by a first separating wall 624 . Said first separating wall 624 axially defines and f luid-tightly seals the motor chamber 620 .

[0038] Preferably, said first separating wall 624 is comprised in the first casing 61 .

[0039] In an alternative embodiment , the first separating wall 624 is comprised in the second casing 62 .

[0040] In a further embodiment , the first separating wall 624 consists of a portion comprised in the first casing 61 and a portion comprised in the second casing 62 . [0041] Preferably, the first separating wall 624 is traversed by and supports the shaft 3 .

[0042] According to a preferred embodiment , the first separating wall 624 comprises at least one cooling hole 624 ' suitable for putting the rotor chamber 621 in fluid communication with the impeller chamber 61 in such a way as to allow the cooling liquid to flow also in said impeller chamber 61 .

[0043] According to a preferred embodiment , the intermediate tubular wall 625 extends comprising a first end 625 ' proximal to the first casing 61 , preferably f luid-tightly engaging the first separating wall 624 , and a second end 625 ' ’ proximal to the second cas ing 62 , f luid-tightly engaging the second separating wall 623 .

[0044] According to the present invention, the command chamber 630 and the stator chamber 622 are separated by a second separating wall 623 . Said second separating wall 623 , together with the first separating wall 624 , axially defines and f luid-tightly seals the motor chamber 620 .

[0045] In a first preferred embodiment , the second separating wall 623 is comprised in the second casing 62 . [0046] In a second preferred embodiment , the second separating wall 623 is comprised in the first casing 61 .

[0047] In a further embodiment , the second separating wall

623 consists of a portion comprised in the second casing 62 and a portion comprised in the third casing 63 .

[0048] According to a preferred embodiment , the third casing 63 comprises a closing cover 635 suitable for tightly sealing the command chamber 630 , in which the electronic command board 5 is housed .

[0049] In a preferred embodiment , the second cas ing 62 comprises an annular side wall 627 which extends parallel to the axis X-X . In addition, said side wall 627 radially defines the motor chamber 620 , preferably the stator chamber 622 .

[0050] Preferably, the side wall 627 tightly engages the first separating wall 624 and the second separating wall 623 .

[0051] According to the present invention, the stator chamber 622 and the command chamber 630 contain an amount of oil . In particular, said amount of oi l fills at least partially said stator chamber 622 and said command chamber 630 in such a way as to cool the stator 42 and the electronic command board 5 by convection . In other words , the oil fills at least partially the free space present in said stator chamber 622 , i . e . the space not occupied by the stator 42 , and in said command chamber 630 , i . e . the space not occupied by the electronic command board 5 .

[0052] According to the present invention, oil and cooling liquid circulate in di f ferent distinct portions of the pump group without ever mixing .

[0053] Preferably, the oil is of the dielectric type .

[0054] In addition, according to the present invention, the second separating wall 623 comprises at least one connection opening 623 ' which fluidically connects the command chamber 630 and the stator chamber 622 .

[0055] In other words , the at least one connection opening 623 ' is crossable by the oil present in the command chamber 630 and in the stator chamber 622 in both directions .

[0056] According to a preferred embodiment , the second separating wall 623 comprises at least one connection opening 623 ' in a position distal to the axis X-X . In other words , said at least one connection opening 623 ' is located in a distal position from the tubular wall 625 . In further other words , the at least one connection opening 623 ' is in a position proximal to the side wall 627 of the second casing 62 .

[0057] According to a preferred embodiment , the second separating wall 623 comprises a plurality of connection openings 623 ' angularly equidistant with respect to the axis X-X .

[0058] Preferably, in fact , the second separating wall 623 comprises at least three connecting openings 623 ' which are angularly equidistant . In this way, with respect to an imaginary plane on which the axis X-X lies , at least one opening is positioned on one side .

[0059] In an embodiment variant , the second separating wall 623 comprises a plurality of connection openings 623 ' comprising a first set of openings distal from the axis X-X and a second set of openings proximal to the axis X- X .

[0060] According to a preferred embodiment , defined as a pair of distinct and concentric circumferences to the axis X-X, said second separating wall 623 comprises , for example , on each of the two circumferences , three angularly equidistant connecting openings 623 ' .

[0061] According to a preferred embodiment , the electronic command board 5 is housed in the command chamber 630 in a region proximal to the second separating wall 623 .

[0062] In a preferred embodiment , the electronic command board 5 is anchored, for example glued or mechanically fixed, to the second separating wall 623 . In other words , the electronic command board 5 is preferably in contact with said second separating wall 623 .

[0063] Preferably, such positioning of the electronic command board 5 involves a high heat exchange with said wall , favoring the cooling of the electronic command board 5 . [0064] According a preferred embodiment , the electronic command board 5 comprises at least one connecting pipe 55 that axially crosses said electronic command board 5 .

[0065] According to a preferred embodiment , the oil flows in said at least one connecting pipe 55.

[0066] According to a preferred embodiment , the oil flowing between the command chamber 630 and the stator chamber 622 flows in the connecting pipe 55 without limitation of direction .

[0067] According to a preferred embodiment , the electronic command board 5 comprises a plurality of connecting pipes 55 .

[0068] In a preferred embodiment , the connecting pipes 55 are equal in number to the number of connecting openings 623 ' . For example , in one embodiment , the connecting openings 623 ' are three in number and the connecting pipes 55 are three in number .

[0069] Preferably, the connecting pipes 55 are positioned in such a way as to face the connecting openings 623 ' .

[0070] According to a preferred embodiment , the shaft 3 comprises an axial hole 300 that extends mainly along the axis X-X .

[0071] Preferably, the cooling liquid flows inside said axial hole 300 . Preferably, the axial hole 300 is through along the shaft 3 . [0072] According to a preferred embodiment , the third casing 63 and the second casing 62 delimit an auxiliary cooling chamber 631 fluidically connected to the rotor chamber 621 , in such a way that said auxiliary cooling chamber 631 is also fluidically reached by the cooling liquid .

[0073] According to a preferred embodiment , said auxiliary cooling chamber 631 is reached by the cooling liquid that flows through the axial hole 300 comprised in the shaft 3 .

[0074] In other words , the axial hole 300 connects the impeller chamber 610 and the auxiliary cooling chamber 631 in fluidic connection .

[0075] According to the present invention, the amount of oil and the position of the connecting openings 623 and of any connecting pipes 55 is such as to favor the heat exchange by convection of the heat present in the stator chamber 622 and in the command chamber 630 towards the "hydraulic part" of the pump group 1 . In other words , the amount of oil and the position of the connecting openings 623 and of the possible connecting pipes 55 is such as to fill the stator chamber 622 and in the command chamber 630 in such a way as to always wet at least one surface of a wall defining a chamber in which the cooling liquid of the system flows , such as the impeller chamber 610 or the rotor chamber 621 or the auxiliary cooling chamber 631 .

[0076] According to a preferred embodiment , the amount of oil and the position of the connecting openings 623 and of any connecting pipe 55 is such as to favor the heat exchange by convection of the heat present in the stator chamber 622 and in the command chamber 630 towards the "hydraulic part" of pump group 1 in any operating position the pump group 1 is positioned in the vehicle . [0077] In other words , according to a preferred embodiment , the pump group 1 is positionable in the vehicle in a vertical position or in a hori zontal position or in an inclined position, always having the same cooling modes .

[0078] According to a preferred embodiment , the oil fills the stator chamber 622 in such a way as to wet all the free surfaces of the coils . In this embodiment , the entire stator 42 is in an oil bath .

[0079] According to a preferred embodiment , the oil fills the entire command chamber 630 in such a way as to wet all the surfaces of the electronic command board 5 . In other words , the electronic command board 5 is in an oil bath .

[0080] According to the present invention, the presence of oil in the stator chamber 622 and in the command chamber

630 ensures cooling of the components contained therein by natural convection in the static steps of the vehicle , and according to forced convection, for example in the motion steps of the vehicle .

[0081] According to a preferred embodiment , the amount of oil fills a part of the stator chamber 622 and a part of the command chamber 630 identi fying a free surface , in such a way that , with the pump group 1 subj ect to shaking, for example due to the motion of the vehicle , the oil is free to move , favoring forced convection cooling .

[0082] Innovatively, the pump group fully ful fills the intended obj ect by overcoming the typical problems of the prior art .

[0083] Advantageously, in fact , the pump group comprises convection oil and speci fic fluidic passages suitable for allowing the oil to wet the components being heated and the components cooled by the flow of cooling liquid, thus favoring the convection cooling of said components .

[0084] Advantageously, the heat produced by the electronic components is ef fectively conducted and transmitted to the cooling liquid .

[0085] Advantageously, the at least one connecting opening allows an accentuated movement of the oil between the chambers , improving the heat exchange of the entire pump group . [0086] Advantageously, the positioning of the connecting openings allows the flow of oil between the chambers in any orientation of the pump group . Advantageously, the pump group is positionable inside a vehicle in any position .

[0087] Advantageously, in the pump group obj ect of the present invention the " insulating" ef fect which is typically due to the presence of spaces in which air is present is extremely reduced . Advantageously, in fact , the possibility that the air is an insulating screen for the heat produced by the stator and/or by the command board is obviated .

[0088] Advantageously, the oil allows the pump group to operate at a uni form temperature . Advantageously, the presence of oil in the stator chamber and in the command chamber allows a uni form temperature .

[0089] Advantageously, the pump group obj ect of the present invention, with the same dimensions with respect to a known pump group, has greater power . Advantageously, the pump group obj ect of the present invention, with the same power with respect to a known pump group, has more compact dimensions .

[0090] It is clear that a person skilled in the art may make changes to the invention described above in order to meet incidental needs , all falling within the scope of protection as defined in the following claims.