TECHNICAL FIELD

The object of the present invention is an electric motor comprising a housing in which there is a cylindrical stator made of ferromagnetic sheets connected in packets with slots evenly distributed around the perimeter on the inside, in which the wire winding is placed.

BACKGROUND ART.

Patent specification number PL228943B1 discloses a cooling system of the internal stator winding of an electric machine with a concentrated winding placed in slots, where in the slots the space between the winding coils is filled with thermally conductive resin, in which there are channels or non-metallic tubes, one or several, wherein the channels or tubes have a round and/or oval cross-section, preferably adapted to the shape of the winding sides. The channels or tubes on the ends are connected in series and/or in parallel to form one circuit, at the ends of which there are stub pipes.

Patent specification EP3357147B1 discloses a stator, which comprises PCS comprising at least one dielectric layer and at least one conductive layer, wherein the PCS is characterized at least in part by a center origin point and a periphery. The stator may also comprise a plurality of first elongated conductive elements extending radially from a first radial distance rO toward the periphery of the PCS, and disposed angularly on the PCS, wherein each first elongated conductive element is comes from preferable first structure. Additionally the stator may comprise a plurality of second elongated conductive elements extending radially from a radial rl from the center origin point PCS toward the center origin point PCS, and disposed angularly on the PCS. In some examples of execution at least one of the first elongated conductive elements is connected with at least one of the second elongated conductive elements in preferable first structure in accordance with the configuration of the connection.

Patent application EP3324522A1 discloses an electric motor having a structure useful for cooling a rotor safely fixed to a rotating shaft and rotating together with the rotating shaft, in which a plurality of permanent magnets are arranged in a circumferential direction, in particular for cooling permanents magnets in the rotor.

Patent application EP3687038A discloses an electric motor that may include a housing provided therein with an accommodating space; a stator having a stator core and provided in the accommodating space of the housing; a rotor having a rotor core and rotatably mounted inside the stator with an air gap therebetween; a rotating shaft provided therein with a hollow portion and having a plurality of rotating shaft injection holes formed at a central portion thereof, so that a cooling fluid introduced into the hollow portion is sprayed through the plurality of rotating shaft injection holes into the rotor core; and a plurality of cooling passages provided in the rotor core, and having one side thereof communicating with each of the plurality of rotating shaft injection holes and another side thereof communicating with the accommodating space, so that the cooling fluid is sprayed in different directions toward opposite ends to a central portion of the rotor core.

All the above solutions are complicated and require significant modifications in the structure of an electric motor. It has been found unexpectedly, that thanks to simple modification of sheets, from which the stator of the electric motor is built, it is possible to enhance the ability of cooling the said motor. DISCLOSURE OF THE INVENTION

An electric motor comprising a housing, in which there is a cylindrical stator made of ferromagnetic sheets connected in packets with slots evenly distributed around the perimeter on the inside, in which the wire winding is placed in accordance with the invention is characterized in that, the stator comprises basic sheets and, additionally, channel sheets, having a diameter larger than the basic sheets, while the channel sheets have holes arranged around the outer perimeter, which after connecting the sheets in the packages form channels for the cooling medium, while the base sheets are placed in packages between the packages of the channel sheets, forming at least one main line for the flow of the cooling medium, while the motor housing is equipped with coolant supply.

Preferably the ratio of the surface area of the channel sheet to the hole in the channel sheet is between 2080: 1 and 2800: 1.

Preferably the stator comprises orifice sheets, which have holes arranged around the outer perimeter, wherein the holes are smaller than the holes in the channel sheets and after connecting the sheets into packages form orifices. Preferably the ratio of the surface area of the orifice sheet to the hole in the orifice sheet is from 24100: 1 to 31900: 1.

Preferably the ratio of the hole area in the channel sheet to the area of the hole in the orifice sheet is from 10.91 : 1 to 11.98: 1.

Preferably the distance between the holes in the channel sheet is from 1.82 and 2.47.

Preferably the distance between the holes in the channel sheet is from 1.82 to 2.47.

The rotor is inside the stator.

In the ferromagnetic core of the stator formed after connecting basic sheets, channel sheets and orifice sheets in packets, the holes in the orifice sheets form orifices (narrowing) between the channels for the cooling liquid and/or between the channels for the cooling liquid, and the main line and/or between the channels for the cooling liquid and the housing.

Such configuration of the sheets forming the stator causes the coolant to wash the channels and the orifices in the sheets and the winding and collects the heat. As a result, the stator is cooled much more efficiently than the state-of-the-art stators. The object of the invention is disclosed at the drawings, where fig. 1 illustrates the cross-section of the motor, fig. 2 - the basic sheet, fig. 3 - the channel sheet, fig. 4 - the orifice sheet, fig. 5 - the cross section of the stator, and detail B in fig. 5 - a part of the cross-section of the stator.

EXAMPLE

An electric motor comprises basic sheets 1, channel sheets 2, and orifice sheets 3, connected in packets and placed in the housing 4. The motor housing 4 is equipped with the coolant supply 5. The winding 6 from wires is distributed around the rotor 7. The winding 6 from wires is placed in slots 8, which are place around the inner perimeter of the sheets 1, 2, 3 connected in packets. The channel sheets 2 have a diameter larger than the basic sheets. The channel sheets 2 have holes 9 arranged around the outer perimeter. The channel sheets have at their rim welding channels 10. The orifice sheets 3 have the same diameter as the channel sheets. The orifice sheets 3 have holes 11 arranged around the outer perimeter. The holes 11 are smaller than the holes 9 in the channel sheets 2. The basic sheets 1 are placed in packets between packets of the orifice sheets 3 and channel sheets 2 forming a main line 12 for flow of the coolant. The holes 9 in the channel sheets 2 after connecting the sheets in a packet form channels 13 for the coolant. The holes 11 in the orifice sheets 3 after connecting the sheets in a packet form orifices 14. After connecting the packets of orifice sheets 3 with the packets of channel sheets 2, the orifices 14 in the orifice sheets 3 form narrowings between the channels 13 and/or between the channels

13 and the main line 12 and or between the channels 13 and the housing 4.

The ratio of the surface area of the channel sheet 2 to the hole 9 in the channel sheet 2 is between 2080: 1 and 2800: 1. 4. The ratio of the surface area of the orifice sheet 3 to the hole 11 in the orifice sheet 3 is from 24100: 1 to 31900: 1. The ratio of the hole area 9 in the channel sheet 2 to the area of the hole 11 in the orifice sheet 3 is from 10.91: 1 to 11.98: 1. The distance between the holes 9 in the channel sheet 2 is from 1.82 and 2.47. The distance between the holes 11 in the channel sheet 2 is from 1.82 to 2.47.