Electric machine, in particular for rail vehicle, having integrated ventilation device

Abstract

The invention relates to an electric machine (10) comprising a rotor (20) and a stator (22) housed in a housing (12), and comprising a motorized fan (42) for cooling the rotor (20) and the stator (22), the electric machine (10) comprising at least one first channel (30) for cooling the stator (22) and at least one second channel (34) for cooling the rotor (20) through which air moved by the fan (42) passes. The electric machine (10) comprises at least one air deflecting member (54) to direct air from the second channel (34) from the second channel (34) to the outlet (40) of the housing (12).

Description

Technical Field

[0001] The invention relates to an electric machine with an integrated ventilation device, in particular for use in a rail vehicle. Background Art

[0002] In the prior art, a motor is known, which includes a rotor and a stator accommodated in a housing, and includes a motorized fan for cooling the rotor and the stator, the motor including at least one first channel for cooling the stator and at least one second channel for cooling the rotor, and air driven by the fan passes through these channels. Summary of the invention

[0003] In particular, the invention relates to an electric machine with an extracted air flow, ie an air flow which is sucked through the cooling ducts by a motorized fan arranged downstream of the cooling ducts.

[0004] There are fans with straight blades, ie each blade is located in a plane containing the axis of rotation of the fan, and fans with inclined blades. Fans with inclined blades allow the flow rate of the air flow to be optimized and the power consumption of the fan's motor to be reduced. In fact, this design confers better aerodynamic efficiency than designs with radial straight blades.

[0005] Note, however, that fans with pitched blades can only operate in one direction of rotation.

[0006] Instead, the rotor of the electric motor can turn in two opposite directions of rotation, thus either in the same direction of rotation as the fan or in the opposite direction of rotation.

[0007] However, it is noted that the air flow is subject to disturbances between the fan and the rotor of the motor and also behaves differently in different directions of rotation.

[0008] In particular, the air from the rotor passes axially through the secondary channels that cool the rotor. At the outlet of these secondary channels, the air is centrifuged and sucked by the fan. As the speed of the rotor increases, this centrifugal effect also increases. The rotating air hits the blades of the fan.

[0009] The intensity of the air velocity is greatest at the rotor outlet, but gradually decreases as it approaches the fan. It is easy to conclude that the closer the fan is to the rotor, the more significant this impact effect is.

[0010] When the rotor rotates in the same direction as the fan, the impact area is larger than when the rotor rotates in the opposite direction to the fan.

[0011] Additionally, there is a change in direction of the air flow past the blades, which is significantly greater when the rotor turns in the same direction as the fan.

[0012] This results in an increase in pressure loss as the rotor turns in the same direction as the fan. As a result, the overall flow rate decreases, which also means a decrease in noise.

[0013] The invention relates in particular to reducing the noise of an electric motor equipped with a motorized fan with inclined blades and allowing to achieve the same behavior (same flow rate and same noise) in both directions of rotation without having to take into account the minimum flow rate for the thermal dimensioning of the electric motor.

[0014] To this end, the invention relates in particular to an electric machine comprising a rotor and a stator accommodated in a housing and comprising a motorized fan for cooling the rotor and the stator, the electric machine comprising at least one first channel for cooling the stator and at least one second channel for cooling the rotor, through which channels the air moved by the fan passes, characterised in that the electric machine comprises at least one air deflection element which directs the air coming from the second channel from the second channel to an outlet of the housing.

[0015] The air guide member is disposed between the second duct and the outlet of the housing, thereby guiding the air without centrifuging the air. Therefore, the air from the one or more second ducts arrives toward the central area of ​​the fan without hitting its blades.

[0016] The electric machine according to the invention may also include one or more of the following features, which may be employed individually or in any technically possible combination.

[0017] The air deflecting member comprises an air guiding portion which is substantially cylindrical in shape.

[0018] The air deflecting element guides the air from the first channel and the air from the second channel separately towards the outlet of the housing, so that the air from the first channel and the air from the second channel do not meet inside the housing.

[0019] The housing comprises a first wall comprising, for each first channel, a first air inlet opening facing the first channel and at least one second air inlet opening close to the second channel.

[0020] The motor comprises a motorized part of a fan, the fan comprises secondary blades for ventilation of the motorized part, the motorized part comprises at least one air flow passage, air being sucked by the fan due to the secondary blades of the fan.

[0021] The fan comprises main blades which determine the movement of air to be drawn through the housing, the main blades being of the inclined type.

[0022] An air deflecting member is fixed to a second wall of the housing, the second wall comprising the outlet, the air deflecting member extending longitudinally up to the vicinity of the rotor, so that the air leaving each second channel has to pass through the air deflecting member.

[0023] The outlet is delimited by an outer contour defined by an outer diameter and by an inner contour defined by an inner diameter, the air deflecting member comprising an air guiding portion having a diameter between the outer diameter and the inner diameter.

[0024] The air deflecting means comprise substantially radial straightening blades.

[0025] The invention also relates to a rail vehicle, characterized in that it comprises at least one electric motor as defined above. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Various aspects and advantages of the invention will be set out in the following description, which is given by way of example only and with reference to the accompanying drawings, in which:

[0027] [ Figure 1 ] Figure 1 is an axial cross-sectional half view of a motor according to an exemplary embodiment of the present invention;

[0028] [ Figure 2 ] Figure 2 yes Figure 1 A perspective view of a wall of a housing of an electric machine equipped with a deflection element according to the invention. DETAILED DESCRIPTION

[0029] Figure 1 An electric machine 10 according to an exemplary embodiment of the present invention is shown.

[0030] Generally, the electric machine 10 includes a housing 12 that is generally in the shape of a revolution about a central axis X. Figure 1 Only half of the cross-sectional view of the electric machine 10 is shown in FIG. 1 , the other half being similar due to the general shape of revolution of the electric machine about the central axis X.

[0031] The housing 12 comprises a first wall 14 and a second wall 16 , and a circumferential wall 18 in a substantially revolution shape about a central axis X, extending parallel to the central axis X between the first wall 14 and the second wall 16 .

[0032] The electric machine 10 generally includes a rotor 20 and a stator 22 .

[0033] The rotor 20 is integral with an output shaft 24 , which has a generally cylindrical shape about a central axis X about which the rotor 20 and the shaft 24 are rotatably movable.

[0034] In particular, the output shaft 24 is guided in rotation by a first bearing 26 carried by the first wall 14 and a second bearing 28 carried by the second wall 16 .

[0035] At least one first air flow channel 30 for cooling the stator 22 is defined radially between the stator 22 and the circumferential wall 18. Advantageously, the electric machine 10 comprises a plurality of such first channels 30, distributed circumferentially around the central axis X.

[0036] For each first channel 30 , the first wall 14 comprises a first air inlet 32 ​​which is open facing the first channel 30 .

[0037] The rotor 20 also comprises at least one second air flow channel 34 for cooling the rotor 20. Advantageously, the rotor 20 comprises a plurality of such second channels 34, distributed circumferentially around the central axis X.

[0038] The first wall 14 includes at least one second air inlet 36 proximate to the one or more second channels 34 .

[0039] Furthermore, an air gap is defined between the rotor 20 and the stator 22, thereby forming a third air flow passage 38 for cooling the rotor 20 and the stator 22. The third passage 38 is supplied with air by one or more second air inlets 36, for example.

[0040] The second wall 16 includes an air outlet 40 .

[0041] Upstream of the air outlet 40 , the electric machine 10 comprises a fan 42 for drawing air through the housing 12 . The fan 42 is movable in rotation about a central axis X and comprises conventional motorized parts 44 .

[0042] The motor part 44 is carried by the housing 12 by means of a fixing flange 46 connecting the housing 12 to the motor part 44. The fixing flange 46 delimits with the second wall 16 a housing for the fan 42. Advantageously, a lateral air outlet 48 is provided between the second wall 16 and the flange 46.

[0043] The fan 42 comprises main blades 50 which drive the air in motion for drawing it through the housing 12. The main blades 50 are preferably of the inclined type, ie they are each inclined relative to a radial plane, unlike straight blades extending in a radial plane.

[0044] However, it is noted that the invention is also applicable to motors whose fans have straight blades.

[0045] Advantageously, the fan 42 comprises secondary blades 52 for ventilation of the motorized part 44. The motorized part 44 thus comprises at least one air flow passage 47 through which the air is sucked by the fan 42 thanks to the secondary blades 52 of the fan.

[0046] The electric machine 10 according to the invention comprises at least one air deflecting member 54 in order to direct the air coming from each second channel 34 up to the outlet 40 defined in the second wall 16 .

[0047] The air deflection member 54 is shown in more detail at Figure 2 middle.

[0048] For example, the air deflecting member 54 is fixed to the second wall 16 and extends longitudinally to the vicinity of the rotor 20 , so that the air leaving each second channel 34 needs to pass through the air deflecting member 54 .

[0049] For example, the deflection member 54 comprises a fixing foot 55 which is fixed to the second wall 16 , for example by screwing.

[0050] Advantageously, the air deflecting member 54 comprises an air guiding portion 56 so as to define an air passage between each second channel 34 and the outlet 40 .

[0051] The fixing foot 55 is preferably integral with the guide portion 56 .

[0052] Advantageously, the air guiding portion 56 has a generally cylindrical shape. As a variant, the air guiding portion may be conical.

[0053] The outlet 40 is delimited by an outer contour 40a and an inner contour 40b. The outer contour 40a is defined by an outer diameter and the inner contour 40b is defined by an inner diameter, both of which surround the central axis X.

[0054] The diameter of the air guide portion is between the outer diameter and the inner diameter. Thus, the outlet 40 is distributed between a radially inner outlet defined by the inner contour and the air guide portion and a radially outer outlet defined by the air guide portion and the outer contour.

[0055] The air from the second passage 34 is guided toward the radially inner outlet by the guide portion 56 , and the air from the first passage 30 is guided toward the radially outer outlet by the guide portion 56 .

[0056] Therefore, the air from the first passage 30 and the air from the second passage 34 do not meet inside the housing 12 .

[0057] Note that the air from the third passage 38 is also guided by the guide portion 56 toward the radially outer outlet.

[0058] Advantageously, the air deflecting member 54 comprises substantially radial straightening vanes 57 between the guide portion 56 and the inner contour 40b. These straightening vanes 57 serve to reduce the rotation of the air flow leaving the second channel 34.

[0059] Note that the present invention is not limited to the above-described embodiments but may have various supplementary modifications.

Claims

1. An electric motor (10), comprising a rotor (20) and a stator (22) housed in a housing (12), and comprising a motorized fan (42) for cooling the rotor (20) and the stator (22), the electric motor (10) comprising at least one first channel (30) for cooling the stator (22) and at least one second channel (34) for cooling the rotor (20), air moved by the fan (42) passing through the first channel and the second channel, characterized in that: The electric machine (10) comprises at least one air deflecting member (54) for directing the air from the second channel (34) from the second channel (34) to an outlet (40) of the housing (12).

2. The electric machine (10) according to claim 1, wherein: The air deflecting member (54) includes an air guiding portion (56) having a generally cylindrical shape.

3. The electric machine (10) according to claim 1, wherein: The air deflecting member (54) guides the air from the first passage (30) and the air from the second passage (34) separately toward the outlet of the housing (12) so that the air from the first passage (30) and the air from the second passage (34) do not meet inside the housing (12).

4. The electric machine (10) according to claim 1, wherein: The housing (12) includes a first wall (14), the first wall including a first air inlet (32) for each first channel (30) and opening toward the first channel (30); and including at least one second air inlet (36) located near the second channel (34).

5. The electric machine (10) of claim 1, comprising a motorized part (44) of the fan (42), the fan (42) comprising secondary blades (52) for ventilating the motorized part (44), the motorized part (44) comprising at least one air flow passage (47), the air being drawn through the passage by the fan (42) due to the secondary blades (52) of the fan.

6. The electric machine (10) according to claim 1, wherein: The fan (42) comprises main blades (50) which drive the movement of the air for drawing it through the housing (12), the main blades (50) being of the inclined type.

7. The electric machine (10) according to claim 1, wherein: The air deflecting member (54) is fixed to a second wall (16) of the housing, the second wall comprising the outlet (40), the air deflecting member (54) extending longitudinally up to the vicinity of the rotor (20) so that the air exiting from each second channel (34) needs to pass through the air deflecting member (54).

8. The electric machine (10) according to claim 1, wherein: The outlet (40) is delimited by an outer contour (40a) defined by an outer diameter and an inner contour (40b) defined by an inner diameter, and the air deflecting member (54) comprises an air guiding portion (56) having a diameter between the outer diameter and the inner diameter.

9. The electric machine (10) according to claim 1, wherein: The air deflecting member (54) comprises substantially radial straightening blades (57).

10. A track vehicle, characterized in that: It comprises at least one electric machine (10) as claimed in any one of claims 1 to 9.

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