Patent Description:
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 size, i.e. a motor vehicle or an articulated vehicle.

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

In particular, said cooling system is specific for cooling an "operating group" of the vehicle.

In particular, in the present description, "operating group" means a component or a group of components specific for the execution of a specific 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.

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.

In the prior art, many embodiments of pump groups for a cooling system of an operating group are known which differ from each other in terms of size and type of actuation.

Specifically, the pump group object of the present invention falls within this context, having an electric-type drive. In other words, the pump group object 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 effectively cool the electric motor of the pump group and its related components.

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 specifically, the interest in exploiting the cooling liquid for cooling the rotor included therein is known in the prior art.

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

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

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 <CIT> in the name of the Applicant.

On the other hand, these embodiments have an effective cooling of the rotor and/or of the stator, but fail to effectively cool the other portions of the pump group. Examples of these pump groups are known in documents <CIT>, <CIT> and <CIT>.

The object 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 effective cooling of the entire electronic command components, obviating the problems mentioned above.

Such object is achieved by a pump group according to claim <NUM>. The dependent claims relate to preferred embodiment variants having further advantageous aspects.

The object of the present invention is described in detail hereafter, with the aid of the accompanying drawings, in which:.

- <FIG> 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;.

- <FIG> shows a longitudinal sectional view of a pump group according to the present invention, according to a possible embodiment, shown in a horizontal operating position;.

- <FIG> illustrates a longitudinal sectional view of a pump group according to the present invention, according to a possible embodiment, shown in an inclined position.

In the above tables, the reference numeral <NUM> 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.

The pump group <NUM> object of the present invention extends mainly in length with respect to an axis X-X.

The pump group <NUM> object of the present invention comprises an impeller <NUM> rotatable with respect to said axis X-X. In other words, said impeller <NUM> has a center of rotation which lies on said axis X-X.

Preferably, the impeller <NUM> 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 <NUM> object of the present invention is fluidically connectable.

According to the present invention, moreover, the pump group <NUM> comprises a shaft <NUM> which extends in length along the axis X-X. Preferably, said shaft <NUM> comprises a rotating end <NUM> on which the impeller <NUM> is integrally mounted.

According to the present invention, the pump group <NUM> comprises an electric motor <NUM> suitable for driving the shaft <NUM> in rotation.

The electric motor <NUM> comprises a rotor <NUM> and a stator <NUM>. According to a preferred embodiment, the rotor <NUM> and the stator <NUM> are arranged concentrically with respect to the axis X-X.

According to the present invention, the rotor <NUM> is integrally mounted, for example keyed, on said shaft <NUM>: the rotation of the shaft <NUM> and in turn of the impeller <NUM> corresponds to the electronically commandled rotation of the rotor <NUM>. The stator <NUM> axially and circumferentially surrounds the rotor <NUM>. In particular, the stator <NUM> comprises a plurality of stator coils forming a stator.

According to the present invention, the pump group <NUM> comprises an electronic command board <NUM> operatively connected to the motor shaft <NUM> and suitable for commanding the rotation thereof about the axis X-X. In other words, the electronic board <NUM> commands the operation of the electric motor <NUM>, hence the rotation of the shaft <NUM> and in turn of the impeller <NUM>.

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

According to the present invention, the pump body <NUM> comprises along the axis X-X:.

According to the present invention, the second casing <NUM> comprises an intermediate tubular wall <NUM> which extends parallel to the axis X-X positioned between the rotor <NUM> and the stator <NUM>.

Said intermediate tubular wall <NUM> divides a rotor chamber <NUM> and a stator chamber <NUM> in the second casing <NUM>. In other words, the motor chamber <NUM> is divided into a rotor chamber <NUM> and a stator chamber <NUM>. Preferably, the rotor chamber <NUM> and the stator chamber <NUM> are mutually fluid-tightly separated.

According to a preferred embodiment, said first casing <NUM>, and in particular the impeller chamber <NUM> included therein, is fluidly connected with the ducts of the cooling system in which the cooling liquid flows.

According to the invention, the first casing <NUM> and the second casing <NUM> are separated by a first separating wall <NUM>. Said first separating wall <NUM> axially defines and fluid-tightly seals the motor chamber <NUM>.

Preferably, said first separating wall <NUM> is comprised in the first casing <NUM>.

In an alternative embodiment, the first separating wall <NUM> is comprised in the second casing <NUM>.

In a further embodiment, the first separating wall <NUM> consists of a portion comprised in the first casing <NUM> and a portion comprised in the second casing <NUM>.

Preferably, the first separating wall <NUM> is traversed by and supports the shaft <NUM>.

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

According to the invention, the intermediate tubular wall <NUM> extends comprising a first end <NUM>' proximal to the first casing <NUM>, fluid-tightly engaging the first separating wall <NUM>, and a second end <NUM>" proximal to the second casing <NUM>, fluid-tightly engaging the second separating wall <NUM>.

According to the present invention, the command chamber <NUM> and the stator chamber <NUM> are separated by a second separating wall <NUM>. Said second separating wall <NUM>, together with the first separating wall <NUM>, axially defines and fluid-tightly seals the motor chamber <NUM>.

In a first preferred embodiment, the second separating wall <NUM> is comprised in the second casing <NUM>.

In a second preferred embodiment, the second separating wall <NUM> is comprised in the first casing <NUM>.

In a further embodiment, the second separating wall <NUM> consists of a portion comprised in the second casing <NUM> and a portion comprised in the third casing <NUM>.

According to a preferred embodiment, the third casing <NUM> comprises a closing cover <NUM> suitable for tightly sealing the command chamber <NUM>, in which the electronic command board <NUM> is housed.

In a preferred embodiment, the second casing <NUM> comprises an annular side wall <NUM> which extends parallel to the axis X-X. In addition, said side wall <NUM> radially defines the motor chamber <NUM>, preferably the stator chamber <NUM>.

Preferably, the side wall <NUM> tightly engages the first separating wall <NUM> and the second separating wall <NUM>.

According to the present invention, the stator chamber <NUM> and the command chamber <NUM> contain an amount of oil. In particular, said amount of oil fills at least partially said stator chamber <NUM> and said command chamber <NUM> in such a way as to cool the stator <NUM> and the electronic command board <NUM> by convection. In other words, the oil fills at least partially the free space present in said stator chamber <NUM>, i.e. the space not occupied by the stator <NUM>, and in said command chamber <NUM>, i.e. the space not occupied by the electronic command board <NUM>.

According to the present invention, oil and cooling liquid circulate in different distinct portions of the pump group without ever mixing.

Preferably, the oil is of the dielectric type.

The second separating wall <NUM> comprises at least one connection opening <NUM>' which fluidically connects the command chamber <NUM> and the stator chamber <NUM>.

According to the invention, the at least one connection opening <NUM>' is crossable by the oil present in the command chamber <NUM> and in the stator chamber <NUM> in both directions.

According to a preferred embodiment, the second separating wall <NUM> comprises at least one connection opening <NUM>' in a position distal to the axis X-X. In other words, said at least one connection opening <NUM>' is located in a distal position from the tubular wall <NUM>. In further other words, the at least one connection opening <NUM>' is in a position proximal to the side wall <NUM> of the second casing <NUM>.

According to the invention, the second separating wall <NUM> comprises a plurality of connection openings <NUM>' angularly equidistant with respect to the axis X-X.

Preferably, in fact, the second separating wall <NUM> comprises at least three connecting openings <NUM>' 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.

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

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

According to a preferred embodiment, the electronic command board <NUM> is housed in the command chamber <NUM> in a region proximal to the second separating wall <NUM>.

In a preferred embodiment, the electronic command board <NUM> is anchored, for example glued or mechanically fixed, to the second separating wall <NUM>. In other words, the electronic command board <NUM> is preferably in contact with said second separating wall <NUM>.

Preferably, such positioning of the electronic command board <NUM> involves a high heat exchange with said wall, favoring the cooling of the electronic command board <NUM>.

According a preferred embodiment, the electronic command board <NUM> comprises at least one connecting pipe <NUM> that axially crosses said electronic command board <NUM>.

According to a preferred embodiment, the oil flows in said at least one connecting pipe <NUM>.

According to a preferred embodiment, the oil flowing between the command chamber <NUM> and the stator chamber <NUM> flows in the connecting pipe <NUM> without limitation of direction.

According to a preferred embodiment, the electronic command board <NUM> comprises a plurality of connecting pipes <NUM>.

In a preferred embodiment, the connecting pipes <NUM> are equal in number to the number of connecting openings <NUM>'. For example, in one embodiment, the connecting openings <NUM>' are three in number and the connecting pipes <NUM> are three in number.

Preferably, the connecting pipes <NUM> are positioned in such a way as to face the connecting openings <NUM>'.

According to a preferred embodiment, the shaft <NUM> comprises an axial hole <NUM> that extends mainly along the axis X-X.

Preferably, the cooling liquid flows inside said axial hole <NUM>. Preferably, the axial hole <NUM> is through along the shaft <NUM>.

According to a preferred embodiment, the third casing <NUM> and the second casing <NUM> delimit an auxiliary cooling chamber <NUM> fluidically connected to the rotor chamber <NUM>, in such a way that said auxiliary cooling chamber <NUM> is also fluidically reached by the cooling liquid.

According to a preferred embodiment, said auxiliary cooling chamber <NUM> is reached by the cooling liquid that flows through the axial hole <NUM> comprised in the shaft <NUM>.

In other words, the axial hole <NUM> connects the impeller chamber <NUM> and the auxiliary cooling chamber <NUM> in fluidic connection.

According to the present invention, the amount of oil and the position of the connecting openings <NUM> and of any connecting pipes <NUM> is such as to favor the heat exchange by convection of the heat present in the stator chamber <NUM> and in the command chamber <NUM> towards the "hydraulic part" of the pump group <NUM>. In other words, the amount of oil and the position of the connecting openings <NUM> and of the possible connecting pipes <NUM> is such as to fill the stator chamber <NUM> and in the command chamber <NUM> 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 <NUM> or the rotor chamber <NUM> or the auxiliary cooling chamber <NUM>.

According to a preferred embodiment, the amount of oil and the position of the connecting openings <NUM> and of any connecting pipe <NUM> is such as to favor the heat exchange by convection of the heat present in the stator chamber <NUM> and in the command chamber <NUM> towards the "hydraulic part" of pump group <NUM> in any operating position the pump group <NUM> is positioned in the vehicle.

In other words, according to a preferred embodiment, the pump group <NUM> is positionable in the vehicle in a vertical position or in a horizontal position or in an inclined position, always having the same cooling modes.

According to a preferred embodiment, the oil fills the stator chamber <NUM> in such a way as to wet all the free surfaces of the coils. In this embodiment, the entire stator <NUM> is in an oil bath.

According to a preferred embodiment, the oil fills the entire command chamber <NUM> in such a way as to wet all the surfaces of the electronic command board <NUM>. In other words, the electronic command board <NUM> is in an oil bath.

According to the present invention, the presence of oil in the stator chamber <NUM> and in the command chamber <NUM> 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.

According to a preferred embodiment, the amount of oil fills a part of the stator chamber <NUM> and a part of the command chamber <NUM> identifying a free surface, in such a way that, with the pump group <NUM> subject to shaking, for example due to the motion of the vehicle, the oil is free to move, favoring forced convection cooling.

Innovatively, the pump group fully fulfills the intended object by overcoming the typical problems of the prior art.

Advantageously, in fact, the pump group comprises convection oil and specific 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.

Advantageously, the heat produced by the electronic components is effectively conducted and transmitted to the cooling liquid.

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.

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.

Advantageously, in the pump group object of the present invention the "insulating" effect 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.

Advantageously, the oil allows the pump group to operate at a uniform temperature. Advantageously, the presence of oil in the stator chamber and in the command chamber allows a uniform temperature.

Advantageously, the pump group object of the present invention, with the same dimensions with respect to a known pump group, has greater power. Advantageously, the pump group object of the present invention, with the same power with respect to a known pump group, has more compact dimensions.

Claim 1:
A pump group (<NUM>), for a cooling system of an operating group of a vehicle, preferably of the engine group, which extends relative to an axis (X-X) and comprises:
i) an impeller (<NUM>) rotatable about the axis (X-X);
ii) a shaft (<NUM>), which extends along the axis (X-X), onto which the impeller (<NUM>) is integrally mounted;
iii) an electric motor (<NUM>) comprising a rotor (<NUM>) integrally mounted on the shaft (<NUM>) and a stator (<NUM>) which axially and circumferentially surrounds the rotor (<NUM>) ;
iv) an electronic command board (<NUM>) operatively connected to the electric motor (<NUM>);
v) a pump body (<NUM>) comprising, along the axis (X-X):
- a first casing (<NUM>) in which the impeller (<NUM>) is housed in an impeller chamber (<NUM>);
- a second casing (<NUM>) in which the electric motor (<NUM>) is housed in a motor chamber (<NUM>), wherein the first casing (<NUM>) and the second casing (<NUM>) are separated by a first separating wall (<NUM>), wherein the second casing (<NUM>) comprises an intermediate tubular wall (<NUM>) which extends parallel to the axis (X-X) positioned between the rotor (<NUM>) and the stator (<NUM>), said intermediate tubular wall (<NUM>) comprising a first end (<NUM>') fluid-tightly engaging the first separating wall (<NUM>), and a second end (<NUM>") fluid-tightly engaging a second separating wall (<NUM>), so that a rotor chamber (<NUM>) and a stator chamber (<NUM>) mutually fluid-tightly separated are defined in the motor chamber (<NUM>);
- a third casing (<NUM>) in which the electronic command board (<NUM>) is housed in a command chamber (<NUM>);
wherein the command chamber (<NUM>) and the stator chamber (<NUM>) are separated by the second separating wall (<NUM>); and
wherein the stator chamber (<NUM>) contains an amount of oil which at least partially fills the stator chamber (<NUM>) so that the stator (<NUM>) is cooled by convection;
wherein the pump group (<NUM>) is characterized in that the command chamber (<NUM>) contains an amount of oil which at least partially fills the command chamber (<NUM>) so that the electronic command board (<NUM>) is cooled by convection; and in that the second separating wall (<NUM>) comprises a plurality of connection openings (<NUM>') angularly equidistant, which fluidically connects the command chamber (<NUM>) and the stator chamber (<NUM>) and which are crossable by the oil present in the command chamber (<NUM>) and in the stator chamber (<NUM>) in both directions.