Patent Description:
In the description, the term "vehicle" means any means of locomotion that comprises an internal combustion engine and also hybrid powered vehicles, without any limitation related to type or size, i.e. an automobile or an articulated vehicle.

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

In particular, said cooling system is specific to the cooling of a "operating group" of the vehicle.

In particular, in the present description, "operating group" means a specific component or group of components for carrying out a specific operation required for vehicle movement. In a preferred embodiment, the "operating group" comprises the engine group, for example an internal combustion engine or an electric motor.

In additional embodiment variants, the "operating group" comprises other components of the vehicle, both mechanical-type components, such as a transmission assembly, and electrical-type components, such as a "battery assembly" included in the vehicle.

There are many embodiments in the prior art of pump groups for an operating group cooling system which differ from each other in terms of size and type of drive.

Specifically, the pump group of the present invention falls within this context, having an electric drive. In other words, the pump group of the present invention comprises at least one electric motor which drives the rotation of the impeller included therein, thus propelling the cooling liquid which flows in the cooling system to which the pump group is fluidically connectable.

There are multiple known technical solutions of pump groups comprising an electric drive in which the main problem of this type of pump group has been confronted, i.e. the need to effectively cool the electric motor of the pump group and its related components.

In particular, there are known embodiments of pump groups in which the cooling liquid present in the chamber where the impeller is housed is also used to cool the electric motor and its related components. Even more specifically, in the prior art the cooling liquid is used to cool the rotor of the electric motor. Examples of known pump groups of this type are disclosed in <CIT>, <CIT>, <CIT>, <CIT>, <CIT> and <CIT>.

However, these embodiments have complex geometries particularly due to the need to develop a hydraulic portion, i.e. a portion in which said cooling liquid flows, which is particularly complex. In addition, some pump groups have particularly large dimensions that poorly meet the needs of the automotive sector which require compact dimensions and overall sizes so that they take up as little space as possible.

The purpose of the present invention is therefore to provide a pump group for a cooling system of an operating group of a vehicle effectively cools all the controlling electronic components, thus solving the problems mentioned above.

This purpose is achieved by a pump group according to claim <NUM>. The dependent claims relate to preferred embodiment variants having further advantageous features.

The subject matter of the present invention is described below in detail, in reference to the enclosed drawings, in which:.

In the above figures, the reference number <NUM> refers to a pump group for a cooling system of an operating group of a vehicle as a whole, preferably for cooling the operating group, for example an internal combustion operating group.

The pump group <NUM> of the present invention lies mainly lengthwise with respect to an axis X-X.

The pump group <NUM> of the present invention comprises an impeller <NUM> rotatable about 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 designed to perform a suction action on the cooling liquid preferably in the axial direction, and to perform a propelling 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> of the present invention is fluidically connectable.

Furthermore, according to the present invention the pump group <NUM> comprises a shaft <NUM> that lies lengthwise 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 rotating the shaft <NUM>.

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 controlled 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 stator poles.

According to a preferred embodiment, the pump group <NUM> comprises an electronic control board operationally connected to the motor shaft <NUM> and suitable for controlling the rotation thereof about the axis X-X. In other words, the electronic board controls 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> which lies 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:.

In particular, the impeller chamber <NUM> and the motor chamber <NUM> are sealed from each other. In other words, the "hydraulic portion" in which the cooling liquid flow is exclusively in the impeller casing <NUM> separated from the "electrical portion" contained in the motor casing <NUM> by the presence of the separating and supporting element <NUM>.

According to a preferred embodiment, said separating and supporting element <NUM> substantially has the shape of a flange and is engaged sealingly by the impeller casing <NUM> on one side and by the motor casing <NUM> on the other side.

Preferably, the shaft <NUM> straddles the separating and supporting element <NUM> identifying the impeller end <NUM>, on the one hand, and a motor end <NUM> on which the electric motor <NUM><NUM> is engaged opposite the other side.

According to the invention, the collar <NUM> extends by an axial section parallel to the axis X-X, comprising an axial passage <NUM> along which the shaft <NUM> is housed and extends.

According to the invention, the collar <NUM> has a tapered cross-section comprising a pointed end <NUM>' proximal to the rotor <NUM>, preferably housed in the stator <NUM>.

In other words, the collar <NUM> has a flange end <NUM>" proximal to the impeller <NUM> with a cross-section greater than the pointed end <NUM>'. The flange end <NUM>" is therefore suitable for supporting greater loads and forces.

According to a preferred embodiment, the separating and supporting element <NUM> comprises a sealing member <NUM> for providing a hydraulic seal between the impeller casing <NUM> and the motor casing <NUM>.

Preferably, the sealing member <NUM> is housed in the collar <NUM>, in particular in the axial passage <NUM>.

Preferably the sealing member <NUM> is positioned axially proximal to the impeller chamber <NUM>.

According to a preferred embodiment, the sealing member <NUM> is of the type comprising a first sealing member <NUM> and a second sealing member <NUM> mutually suitable for axially delimiting an airtight chamber <NUM>.

Preferably, the first sealing member <NUM> is of the water-tight type.

Preferably, the second sealing member <NUM> is of the oil-tight type. Preferably, the second sealing member <NUM> is an oil retainer.

According to a preferred embodiment, the separating and supporting element <NUM> comprises at least one vent channel <NUM> for fluidly connecting the airtight chamber <NUM> to the outside environment.

According to the present invention, the pump group <NUM> comprises an amount of oil suitable for cooling the motor <NUM> and the stator <NUM> by convection.

Such quantity of oil is stored in the motor chamber <NUM> and is then moved by rotation of the rotor <NUM>.

Consequently, the oil is suitable for promoting cooling by thermal convection under both static and dynamic conditions.

According to the present invention, the oil and cooling liquid circulate in separate portions of the pump group <NUM> without ever mixing. This eventuality is indeed prevented by the presence of the sealing member <NUM> and by the rotating member <NUM>.

Preferably, the oil is of the dielectric type.

According to a preferred embodiment, the oil has a viscosity such that it allows for easy movement of the rotor <NUM>. In other words, the presence of oil does not in any way hamper the movement of the rotor <NUM>.

According to the invention, as mentioned earlier, the shaft <NUM> comprises a rotating member <NUM> operationally connected to the collar <NUM>.

According to the invention, the rotating member <NUM> is housed in the axial passage <NUM>.

According to a preferred embodiment, the rotating member <NUM> is radially engaged with the shaft <NUM> and the collar <NUM>, particularly with the wall defining the axial passage <NUM>.

According to a preferred embodiment, the rotating member <NUM> is a bearing, preferably a double-row ball bearing. In other words, the rotating member <NUM> has two rings of ball bearings <NUM>, <NUM> axial spaced apart along the axis X-X.

This means that a first ring of ball bearings <NUM> is proximal to the electric motor <NUM> and the second ring of ball bearings <NUM> is proximal to the impeller <NUM>.

According to the present invention, the rotating member <NUM> does not serve an oil-tightness function.

According to the invention, the collar <NUM> comprises a lubrication conduit <NUM> through which the oil is free to flow in order to keep the rotating member <NUM> lubricated.

According to a preferred embodiment, the collar <NUM> comprises a plurality of lubrication conduits <NUM>, preferably evenly spaced apart angularly.

Preferably, the collar <NUM> comprises at least three lubrication conduits <NUM>. In this way, each side comprises at least one lubrication conduit <NUM> with respect to an imaginary plane on which the axis X-X lies.

According to a preferred embodiment in which the oil has a specific viscosity and the lubrication conduit <NUM> has a diameter that allows the oil to flow as a function of the viscosity thereof.

According to the invention, the lubrication conduit <NUM> comprises an inlet <NUM> suitable for receiving oil and promoting the flow thereof through the lubrication conduit <NUM> toward the rotating member <NUM>.

According to the invention, said inlet <NUM> has larger dimensions than the diameter of the lubrication conduit <NUM>.

According to a preferred embodiment, said inlet <NUM> also serves the purpose of acting as an oil compartment or tank so as to collect a predefined quantity of oil and allow it to flow into the corresponding lubrication conduit <NUM>. Preferably, the inlet <NUM> is suitable for acting as a funnel for the oil toward the lubrication conduit <NUM>. According to a preferred embodiment, the oil that is contained in the inlet <NUM> is suitable for lubricating the rotating member <NUM>.

According to a preferred embodiment, the lubrication conduit <NUM> is positioned axially ao as to allow oil to flow to the second ring of ball bearings <NUM>.

Preferably, the lubrication conduit <NUM> lubricates both the first ring of ball bearings <NUM> and the second ring of ball bearings <NUM>.

According to a preferred embodiment, the first ring of ball bearings <NUM> is lubricated directly by the oil in the motor chamber <NUM>.

Preferably, the second ring of ball bearings is also lubricated by the oil in the motor chamber <NUM>, which lubricates the first ring of ball bearings <NUM>.

According to the invention, the amount of oil is such that it establishes a free surface that is higher than the lubrication conduit <NUM> with respect to the axis X-X, so as to ensure a flow of oil to the rotating member <NUM>.

According to the invention, the quantity of oil is such that it establishes a free surface that is higher than the lubrication conduit <NUM> with respect to the axis X-X in any spatial position of the pump group <NUM>.

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, and still have the same cooling properties, ensuring a high level of cooling of the electrical components. Preferably, the rotating member <NUM> is still lubricated so as to operate effectively, thus ensuring a high rotational speed of the impeller <NUM>.

Innovatively, the pump group amply fulfills the intended purpose by solving the typical problems of the prior art.

Indeed, the pump group advantageously comprises oil suitable for promoting the convection cooling of the "electrical portion" of the pump group.

Advantageously, the pump group effectively cools both the stator and the rotor by taking advantage of the fact that said rotor drives the oil and promotes forced convection.

Advantageously, the oil effectively lubricates the rotating member which operates under optimal conditions.

Advantageously, the heat generated by the electronic components is effectively carried and transmitted to the cooling liquid through the oil and the collar.

Advantageously, the presence of the oil is such that it evens out the temperature inside the motor chamber.

Advantageously, the pump group has a very limited number of components.

Advantageously, the pump group has extremely simple assembly steps.

Advantageously, the amount of oil and the number and/or positioning of the lubrication conduits are such that lubrication of the rotating member in any position of the pump group is assured. Advantageously, the pump group is positionable inside a vehicle in any position.

Advantageously, the lubrication conduits are designed to ensure an inflow of lubricating oil even at the startup of the vehicle. In other words, the lubrication conduits advantageously store a quantity of oil employable during vehicle startup.

Claim 1:
A pump group (<NUM>), for a cooling system of an operating group of a vehicle, preferably the engine assembly, which lies with respect to an axis (X-X) and comprises:
i) an impeller (<NUM>) rotatable about the axis (X-X);
ii) a shaft (<NUM>) that lies along the axis (X-X) comprising an impeller end (<NUM>) 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>) axially and circumferentially surrounding the rotor (<NUM>); vi) a pump body (<NUM>) comprising, along the axis (X-X):
- an impeller casing (<NUM>) in which the impeller (<NUM>) is housed in an impeller chamber (<NUM>) in which the cooling liquid circulates;
- a separating and supporting element (<NUM>) comprising a collar (<NUM>) which engages and rotatably supports the shaft (<NUM>);
- a motor casing (<NUM>) in which the electric motor (<NUM>) is housed inside a motor chamber (<NUM>);
wherein the impeller chamber (<NUM>) and the motor chamber (<NUM>) are mutually fluid-tightly separated;
wherein the motor chamber (<NUM>) contains an amount of oil suitable for cooling the rotor (<NUM>) and the stator (<NUM>) by convection, wherein the rotation of the rotor (<NUM>) propels the oil;
wherein the collar (<NUM>) lies along an axial section parallel to the axis (X-X) comprising an axial passage (<NUM>) which houses the shaft (<NUM>) and along which the shaft (<NUM>) extends;
wherein the shaft (<NUM>) comprises a rotating member (<NUM>) operationally connected to the collar (<NUM>), housed in the axial passage (<NUM>), wherein the collar (<NUM>) comprises a lubrication conduit (<NUM>) through which oil flows lubricating the rotating member (<NUM>);
wherein the conduit (<NUM>) comprises an inlet (<NUM>) having larger dimensions than the diameter of the lubrication conduit (<NUM>), suitable for accommodating oil and promote the outflow of said oil into the lubrication conduit (<NUM>) towards the rotating member (<NUM>);
wherein the amount of oil is such that it identifies a free surface, which is higher than the lubrication conduit (<NUM>) relative to the axis (X-X), to ensure an inflow of oil to the rotating member (<NUM>) in any spatial position of the pump group (<NUM>);
wherein the pump group (<NUM>) is characterized in that the collar (<NUM>) has a tapered section comprising a pointed end (<NUM>') proximal to the rotor (<NUM>).