Search

EP-3654499-B1 - ROTARY ELECTRICAL MACHINE PROVIDED WITH SEALING ELEMENTS LIMITING HOT AIR FEEDBACK

EP3654499B1EP 3654499 B1EP3654499 B1EP 3654499B1EP-3654499-B1

Inventors

  • BEN OMRANE, RYADH
  • MONTEIL, CHRISTOPHE
  • BOUSSICOT, Frédéric

Dates

Publication Date
20260513
Application Date
20180202

Claims (14)

  1. Rotating electrical machine (15) comprising: - a rotor (16) mounted on a shaft (17) with axis (X), - a stator (18) surrounding the rotor (16) with an air gap between the external periphery of the rotor (16) and the internal periphery of the stator (18), the stator having a winding provided with phase outputs (26), - a bearing (21) comprising openings (472) allowing the passage of phase outputs (26), and - a fan (38), fixed on the rotor (16) of the machine, allowing the creation of an air current entering the enclosure of the rotating electrical machine and exiting said enclosure, where said rotating electrical machine (15) comprises at least one sealing element (50) fixed on the bearing (21) to at least partially seal one of said openings (472) of the bearing (21), characterized in that said sealing element (50) extends at least partly into a thickness of the corresponding opening (472), in that the sealing element (50) comprises a base wall (51) from which at least two arms (52) extend delimiting a passage space (55) for the phase output (26), in that the arms (52) are monobloc with the base wall (51) and in that the sealing element (50) comprises chamfered lateral faces (70).
  2. Rotating electrical machine according to claim 1, characterized in that the base wall (51) is located on the side of the external periphery of the bearing (21).
  3. Rotating electrical machine according to any one of claims 1 and 2, characterized in that the passage space (55) is open on the side opposite to the base wall (51) of the sealing element (50).
  4. Rotating electrical machine according to any one of claims 1 to 3, characterized in that the sealing element (50) comprises at least three arms (52), two consecutive arms (52) delimiting a passage space (55) for a phase output (26).
  5. Rotating electrical machine according to any one of claims 1 to 4, characterized in that the arms (52) extend axially in the opening (472).
  6. Rotating electrical machine according to any one of claims 1 to 5, characterized in that the sealing element (50) comprises stiffening grooves (71).
  7. Rotating electrical machine according to any one of claims 1 to 6, characterized in that the sealing element (50) is made of a plastic material.
  8. Rotating electrical machine according to any one of claims 1 to 7, characterized in that an anti-recirculation device for air flow (74) is positioned between the bearing (21) and a heat sink (32).
  9. Rotating electrical machine according to the preceding claim characterized in that the anti-recirculation device is positioned against the external face of the flange of the bearing (21) turned towards the side opposite to the rotor (16).
  10. Rotating electrical machine according to any one of claims 8 and 9, characterized in that the anti-recirculation device for air flow (74) is an annular plate (74), preferably formed of a plastic material to allow electrical insulation between the heat sink 32 and the bearing 21.
  11. Rotating electrical machine according to any one of claims 8 to 10, characterized in that the plate (74) comprises openings allowing the passage of phase outputs (26) through said plate.
  12. Rotating electrical machine according to any one of claims 1 to 11, characterized in that the openings (472) are axial and in that the bearing (21) comprises lateral openings (471) for the passage of air which are in the extension of the openings (472) allowing the passage of phase outputs (26).
  13. Rotating electrical machine according to any one of claims 1 to 12, characterized in that the sealing elements (50) are inserted inside the corresponding openings (472) following an axial displacement (A4).
  14. Rotating electrical machine according to any one of claims 1 to 13, characterized in that the machine also comprises an electronic power module comprising a rectifier and inverter bridge.

Description

The invention relates to a rotating electrical machine equipped with sealing elements that limit the recirculation of hot air. The invention finds a particularly advantageous, but not exclusive, application with rotating electrical machines operating at least in alternator mode. Rotating electrical machines, as is well known, consist of a stator and a rotor attached to a shaft. The stator and rotor are mounted in a housing configured to rotate the shaft on bearings via roller bearings. The rotor may be a claw rotor with two pole wheels and a core around which an excitation coil is wound. In another example, the rotor has a body formed by a stack of sheet metal held together by a suitable fastening system. The rotor has poles formed, for example, by permanent magnets housed in cavities within the rotor's magnetic core. Alternatively, in a so-called salient-pole design, the poles are formed by coils wound around rotor arms. Furthermore, the stator comprises a body made of stacked thin sheets forming a ring, the inner face of which has inward-opening slots to receive phase windings. These windings pass through the slots in the stator body and form coils protruding from either side of the stator body. The phase windings are made, for example, from a continuous wire coated with enamel or from conductive elements shaped like pins joined together by welding. These windings are polyphase windings connected in a star or delta configuration, the outputs of which are connected to a power electronic module including, in particular, a rectifier bridge and, where applicable, an inverter in the case of a starter-alternator. As illustrated on the figure 1 To cool the power electronic module 1, a fan 2, fixed to the rotor 3 of the machine, creates a lateral incoming airflow via the arrow F1 inside a passage defined by the face of the heat sink 4 turned towards the bearing 5 and the upper face of the bearing 5 turned towards the heat sink 4 then is pushed laterally outwards from the electrical machine along the arrow F2. The air exiting fan 2 passes over the winding coil 8 and then the phase outputs 6 of the stator 7, heating up. Some of this air is drawn back into the machine along arrow F3 instead of being exhausted to the outside. As a result, the air temperature near the fins 9 of the heat sink 4 is higher, which reduces the machine's cooling capacity. It is known to mount an anti-recirculation flow device 10 between the heat sink 4 and the bearing 5 in order to reduce the recirculation of hot air at the axial openings 11 of the bearing allowing the passage of the phase outputs 6. Due to changes in the electrical machine's configuration, it was necessary to install terminals on the phase outputs 6 for their attachment to the power electronics module 1. This resulted in an increase in the size of the corresponding openings 11 in the bearing 5, and therefore an increase in the hot air recirculation flow towards the power electronics. The device 10 cannot limit this recirculation flow, as it itself requires large holes for the phase outputs 6 to pass through during the electrical machine assembly process. The document FR2978885 describes a rotating electrical machine with chimneys inserted into the bearing openings to provide guidance and electrical isolation of the phase outputs. Furthermore, the document WO2016/063337 describes a sealing device extending from the electronic assembly and fitting into openings in the bearing. The document FROM 10 2007 034325 A1 describes an alternator comprising phase electrical connection parts coming opposite bearing openings. JP 5 368532 B2 And US 2014/203675 A1 are earlier arts illustrating the state of the art. The invention aims to effectively remedy this drawback by proposing a rotating electrical machine according to claim 1. The invention thus makes it possible, through the use of one or more sealing elements, to block the hot air exiting the rotor, while also allowing for a configuration in which the phase outputs are associated with terminals. Indeed, the sealing element(s) can be fixed to the bearing after the phase outputs and their associated terminals have passed through the bearing openings. Furthermore, because the sealing element is positioned at least partially inside the corresponding bearing opening, the invention makes it possible to perform the flow-blocking function without increasing the overall axial length of the rotating electrical machine. According to one embodiment, said sealing element extends totally into the thickness of the corresponding opening. According to one embodiment, the sealing element includes means for snapping with the bearing. According to one embodiment, the snap-on means include at least one elastically deformable tab intended to fit into a housing provided in one face of the bearing. According to one embodiment, the snap-on means comprise two tabs each originating from an end face of said sealing element in a manner opposite to each other.