JP2019503644A - Rotating electric machine with cooling fins - Google Patents

Abstract

  The invention relates to a rotating electrical machine (100) operable in at least an alternator mode to supply power to a motor vehicle, the power electronics circuit being electrically connected to the phase winding of the stator (3) ( 15) and a second surface having a first surface on which the power electronics circuit is mounted and a second surface facing the first surface, the second surface being oriented toward the rear bearing (4). A heat sink (16) including a surface; and a cooling fluid between an upper surface of the rear bearing (4) oriented toward the heat sink (16) and the second surface of the heat sink (16). A rotating electrical machine having a flow path (17) for flow, wherein the second surface of the heat radiating plate (16) has a cooling fin (18), and at least one axial direction of the fin (18). At least the edge It extends axially to the level of the upper surface of the rear bearing (4), relates primarily dynamoelectric machine, characterized in that.

Description

  The present invention relates to a rotating electrical machine having cooling fins. The present invention is particularly advantageous when applied to rotating electrical machines operating at least in the alternator mode, but is not limited thereto.

  In a known manner, the rotating electrical machine includes a stator and a rotor integral with the shaft. The rotor may be integral with the drive and / or driven shaft.

  The stator is mounted on a housing configured to rotate a shaft on the bearing by a rolling bearing. The rotor includes a body that is formed by a plurality of metal plate sheets that are formed into a set by a suitable fastening system. The rotor has a pole, which is formed, for example, by a permanent magnet housed in a cavity disposed in the magnetic material of the rotor. Alternatively, in a so-called “protruding” pole configuration, the pole is formed by a coil wound around the arm of the rotor.

  The stator also includes a main body constituted by a plurality of thin metal plates forming a crown. The inner surface is provided with a notch that opens toward the inside to receive the phase winding. These windings pass through the notches of the stator body to form a sign (coil) protruding from both sides of the stator body. Phase windings are obtained, for example, from continuous wires coated with enamel or from conductive elements in the form of pins connected to each other by welding. Such windings are multiphase windings connected in a star or triangle shape, the output of which is connected in the case of an alternator, in particular to a power electronics circuit with a rectifying bridge. This type of rectifier bridge can dissipate approximately 150 W of energy.

  As described in document FR 2847085, to cool the rectifier bridge, the radiator has a surface on which the power electronics circuit is mounted and an opposite surface that is oriented toward the rear bearing. In this example, a passage for cooling fluid flow, which is air that is moved by a fan supported by a rotor, is disposed between the surface of the rear bearing that is oriented toward the radiator and the surface opposite to the radiator. . Fins are also placed in the fluid flow passages to increase the heat exchange surface.

  The problem is that the length of the cooling fin is limited. This is because it is necessary to ensure a space between the fin and the opposite surface of the rear bearing so that the assembly can be mounted without risk of damage. In other words, since it is necessary to leave a predetermined minimum mounting gap in any case, the electric machine becomes larger due to the axial extension of the fins.

The purpose of the present invention is to
A rotating electrical machine operable in at least an alternator mode to power a motor vehicle,
-Rear bearings;
-At least a rotor fixed to a rotating shaft supported by said rear bearing;
-A stator surrounding the rotor, the stator comprising armature windings having windings constituting the phases of the electric machine;
The rear bearing comprises a lateral opening for outlet of cooling fluid and at least one axial opening for inlet of the cooling fluid into the stator;
A power electronics circuit electrically connected to the phase winding of the stator;
-A heat dissipation including first a first surface on which the power electronics circuit is mounted, and second a second surface facing the first surface and oriented second toward the rear bearing. And
A flow path for the flow of cooling fluid between the upper surface of the rear bearing oriented towards the radiator and the second surface of the radiator;
In rotating electrical machines including
The second surface of the radiator includes cooling fins;
At least one axial end of the fin extends axially to at least the upper surface of the rear bearing;
The above disadvantage is effectively eliminated by proposing a rotating electric machine characterized by the above.

  Thus, without increasing the axial size of the electric machine, the present invention can increase the replacement surface by extending the fins and improve the cooling of the electric machine.

  According to one embodiment, the at least one fin includes a base opposite the opening and includes an axial end extending axially to at least the upper surface of the rear bearing. Thereby, a heat radiator can be mounted | worn without the danger that a fin contacts a back bearing.

  According to one embodiment, the at least one fin includes a portion located inside the axial opening of the rear bearing.

  This makes it possible to have a part of the fin in the acceleration region of the fluid, so that better cooling of the fin can be achieved.

  According to one embodiment, the fin extends only opposite the axial opening of the rear bearing.

  According to an embodiment, the at least one fin further includes a portion facing the solid upper surface of the rear bearing. This makes it possible to obtain a larger fin surface of the radiator.

  According to an embodiment, the rotating electrical machine further includes at least one second fin disposed opposite the axial opening of the rear bearing and spaced from the upper surface of the rear bearing. Thereby, the flow of air inside the electric machine can be promoted.

  According to an embodiment of the preceding example, the axial opening of the rear bearing is a first and second side edge, and the first side edge is more than the second side edge. Defined by first and second side edges proximate to the axis of the rotor and two other end edges connecting the first side edge and the second side edge. And the second fin is one of the fins closest to one of the two end edges.

  According to one embodiment, the rear bearing includes at least one deflector disposed at an outlet of a side opening of the rear bearing. Thereby, loopback of hot air can be reduced, i.e. hot air flowing out from the radial opening of the bearing can be avoided from being re-inhaled.

  According to one embodiment, the rotating electrical machine includes a protective cover that covers the power electronics circuit and the radiator.

  According to one embodiment, the protective cover includes at least one end raised to form the deflector.

  According to one embodiment, the protective cover includes at least one axial opening for passage of the fluid.

  According to an embodiment, the radiator has at least one main opening for passage of the rotating shaft, and the cooling fluid flows from the axial opening of the cover to the axial opening of the rear bearing. At least one vent opening that allows This allows low temperature air to pass through the machine through the axial opening of the cover so as to reduce the temperature of the air being introduced into the electric machine and improve its cooling. When the fluid passes through the opening of the radiator, the replacement surface of the radiator can be enlarged in the air flow path. Thus, the radiator bridge is better cooled.

  According to one embodiment, the radiator includes a plurality of vent openings. This can maximize the axial surface of the radiator that is touched by the axial airflow inside the electric machine.

  According to one embodiment, at least one vent opening extends over a circular portion around the rotating shaft. This can increase the heat exchange area between the radiator opening and the axial channel of the cooling fluid. Thus, the larger area of the radiator is cooled by the axial flow.

  According to one embodiment, the rotating electrical machine includes a position sensor disposed around the rotating shaft and at least partially closing the main opening. Thereby, the size in the axial direction can be suppressed by incorporating the sensor into the thickness of the radiator while obtaining cooling of the radiator.

  According to an embodiment, the position sensor is a resolver that closes the main opening along the entire circumference of the rotating shaft. Thereby, the fluid can be forced to flow into the opening of the radiator, not between the radiator and the shaft.

  The invention will be better understood by reading the following description and examining the drawings that accompany it. These drawings are merely examples of the present invention and are not limiting.

FIG. 3 is a partial sectional view of the rear part of an alternator starter according to the present invention. FIG. 1b shows a modified embodiment of the alternator-starter of FIG. 1a. 1b is a side view of a cooling fin used in the alternator-starter of FIG. The side view which shows the deformation | transformation embodiment of a cooling fin. The side view which shows the deformation | transformation embodiment of a cooling fin. The figure which shows the rear part of the alternator-starter which has the mezzanine in which power electronics are mounted. FIG. 6 is a detailed view of the rear bearing, and shows an opening in which at least a part of the cooling fin extends oppositely. FIG. 4 is a partial cross-sectional view of a modified embodiment of an alternator-starter according to the present invention including a radiator according to the present invention provided with a vent opening. The figure which looked at the heat radiator of FIG. 6 from upper direction. The figure which looked at the deformation | transformation embodiment of the heat radiator by this invention from upper direction. The figure which looked at the deformation | transformation embodiment of the heat radiator by this invention from upper direction.

  Identical, similar or similar elements have the same reference numbers throughout the drawings.

  FIG. 1a is a rear sectional view of an alternator-starter 100 including a cooling device according to the present invention. This alternator-starter 100 is designed to supply power to the vehicle's battery and in-vehicle network in the generator mode, and in the motor mode to provide mechanical power specifically to the vehicle's heat engine to ensure its start-up. It can operate reversibly.

  The alternator-starter 100 includes a rotor 1 having an axis X fixed to a rotating shaft 2. The rotor 1 is surrounded by a stator 3 provided with armature windings 7. The stator 3 is supported by a rear bearing 4 and a front bearing (not shown) that holds the rotating shaft 2 by a rolling bearing 6.

  The alternator-starter 100 includes a rectifier bridge having MOS power transistors. A rectifying bridge is associated with the unit for control of these power transistors. This commutation bridge and these control units together form an alternator-starter power electronics, denoted by reference numeral 15. The power electronics 15 is mounted on the upper surface of the radiator 16. The power electronics circuit 15 can be electrically connected to the phase winding of the stator 3 directly or using a connector.

  Specifically, a connector (not shown) may include a track to connect to the phase and to be overmolded with a plastic material. The connector may be fixed in the bearing 4 between the bearing 4 and the fin 181 of the radiator 16.

  The surface of the radiator 16 oriented in the axial direction toward the rear bearing 4 forms a wall of the cooling fluid flow path 17 in the alternator-starter 100. The other wall of the flow path 17 is formed by the upper surface of the rear bearing 4 that is oriented toward the radiator 16.

  The protective cover 11 includes an opening 11 a disposed to face the fluid flow path 17. As a result, a cooling fluid, specifically air, is introduced laterally behind the alternator-starter 100 through these openings 11a, and then flows through the flow path 17 below the radiator 16 to provide power. The electronics 15 are cooled. The fan 5 fixed to the rotating shaft 2 or the rotor 1 ensures the suction of air or other fluid inside the flow path 17. The air flows toward the axial opening 4 a of the bearing 4 before being discharged through the side opening 4 b of the bearing 4.

  The radiator 16 includes cooling fins 18, 18 ′, 18 ″, 18 ″ ″ and 18 ″ ″ on the lower surface opposite to the surface supporting the power electronics. In the embodiment of FIGS. 1 a and 2, the fin 18 includes a first portion 181 that extends opposite the solid surface of the bearing 4 and a second portion 182 that is longer in the axial direction than the first portion 181. In this case, the second portion 182 is disposed opposite the corresponding opening 4a of the bearing 4 and extends at least partially into the opening 4a. The portion 182 of the fin 18 is considered as “facing” the central opening 4a when a straight line passing through the portion 182 perpendicular to the plane of the radiator 16 also passes through the corresponding axial opening 4a.

  As shown in FIG. 2, the heat radiator 16 also includes a fin 18 ′ disposed to face the solid surface of the bearing 4. The fin 18 ′ has an axial end that is spaced from the surface of the bearing 4.

  In the embodiment of FIG. 3 a, the fin 18 ″ is disposed opposite the opening 4 a and is spaced from the upper surface of the bearing 4. More specifically, as shown more clearly in FIG. 5, each opening 4a includes a first side edge 41 and a second side edge 42, the first edge 41 being the second edge. 42 is closer to the axis X. Furthermore, each opening 4 a includes two other end edges 43 and 44 that connect the first edge 41 and the second edge 42. The fin 18 ″ corresponds to a fin that is disposed closest to one of the two end edges 43 and 44 that define the opening 4 a. Thereby, it becomes easy for the air inside the corresponding opening 4a to flow through the arm 45 separating the two continuous openings 4a.

  In the embodiment of FIG. 3 b, the fins 18 ′ ″ arranged opposite the opening 4 a have ends that extend in the axial direction substantially to the upper surface of the rear bearing 4.

  In the embodiment of FIG. 1b, the fins 18 "" "extend opposite only the corresponding opening 4a. That is, the fin 18 ″ ″ ″ does not have the portion 181 that extends to face the solid surface of the bearing 4 that faces the radiator 16.

  Adjacent fins form radial channels that guide the cooling fluid in the flow path 17. Thus, these channels are the “U” of the heat sink 16 formed between the lower surface formed by the rear bearing 4, the two sides facing the two adjacent fins, and the two adjacent fins. A shape base. Advantageously, the fins 18, 18 ′, 18 ″, 18 ′ ″, 18 ″ ″ are arranged radially in the direction of fluid flow concentrated towards the axial opening 4 a of the rear bearing 4. Is done. Thus, after cooling of the radiator 16 via the fins 18 where an air flow along the length of the fins, the power electronics 15 is cooled by conduction.

  Moreover, the heat radiator 16 includes a main opening 16a so as to allow the rotation shaft 2 to pass therethrough. In the embodiment of FIGS. 1 a and 1 b, the main-axis opening 16 a is configured such that a space 22 exists between the rotary shaft 2 and the radiator 16, and air can also flow through this space 22. Is done. This space 22 together with the space separating the shaft 2 from the power electronics 15 forms an axial channel for fluid flow.

  Since the opening 11b in the axial direction is provided in the base of the protective cover 11, the air 22 is sucked through these openings 11b of the alternator-starter and joined to the flow path 17 below the radiator 16 so that the space 22 It flows along the rotating shaft 2 via.

  As a modification, as shown in FIG. 7, a sensor 23 for measuring the angular position of the rotating shaft 2 is arranged around the rotating shaft 2. In this case, the position sensor 23 is a resolver that surrounds the entire circumference of the shaft of the rotor 2 and closes the opening 16a.

  In this case, the radiator 16 includes a ventilation opening 16b which is also shown in FIG. The ventilation opening 16 b allows air to flow from the axial opening 11 b of the cover 11 to the axial opening 4 a of the rear bearing 4. Thus, this maximizes the axial surface of the radiator 16 that the axial airflow contacts within the machine.

  As shown in FIGS. 7 and 8a, the vent opening 16b may have a circular shape. In the embodiment of FIG. 7, the openings 16b are aligned with respect to each other. In contrast, in the embodiment of FIG. 8a, the openings 16b are arranged circumferentially around the main openings 16a.

  As a variant, the opening 16b may have an elongated shape that extends over a circular part around the rotating shaft 2 (see FIG. 8b).

  In the embodiment of FIGS. 8a and 8b, the radiator 16 includes a radial notch 16c to incorporate a Hall effect position sensor instead of a resolver.

  As a modification, the radiator 16 includes a single vent opening 16b.

  Therefore, the power electronics 15 first passes through the flow path 17 in the lateral direction and then in the radial direction through the flow path 22 or the opening 16b so that the air obtained from the outside merges with the flow path 17. Cooled down. This additional axial air flow increases the overall air flow in the machine, allowing better cooling of the internal components of the alternator, such as the armature windings (coils).

  The cooling fluid flow path at the rear of the alternator-starter is shown in FIGS. 1a, 1b and 6 by arrows and dotted lines.

  A deflector 24 is disposed downstream of the opening 4 b provided in the rear bearing 4. The deflector 24 allows the fluid inlet to be moved away from the fluid outlet so that the fluid flowing out of the alternator-starter is not immediately reintroduced into the flow path 17. Thus, it is avoided that the hot fluid obtained from the alternator-starter is substantially recirculated.

  The deflector 24 can be fixed in the vicinity of the opening 4 b in the bearing 4. Further, as shown in FIGS. 1 a, 1 b, and 6, the deflector 24 can be formed on the protective cover 11 by raising an end portion of the protective cover, for example.

  The protective cover 11 can cover all of the rear part of the alternator-starter. That is, the protective cover 11 covers all of the power electronics 15 and the rear bearing 4 attached to the radiator 16. In this case, the protective cover 11 may include an opening located downstream of the side opening 4b of the rear bearing 4 and designed to allow fluid to be discharged from the alternator-starter.

  The radiator 16 is fixed to the rear bearing 4 by an assembly tie rod (assembly connection rod) 20. According to one embodiment, the tie rod 20 is the same as that normally used to secure the bearing to the magnetic circuit of the starter 3.

  As clearly shown in FIG. 4, the rear bearing 4 and the radiator 16 form a mezzanine floor (mezzanine) on the bearing 4. The mezzanine floor is secured to the bearing 4 by a fixed stud 21. There are at least two fixed studs 21. They are distributed between the fins 18.

  The electrical machine may also include an electrically insulating material layer disposed between the lower surface of the radiator 16 and the rear bearing 4 to avoid the risk of electrical contact between these two elements. Advantageously, this insulating material layer is fixed to the outer surface of the rear bearing 4 and has an air passage opening opposite the air passage opening of the rear bearing 4 for the passage of cooling fluid.

  The above-described cooling device for alternator-starters can generally be realized in any type of alternator, including in particular a rotor with pawls or protruding poles.

Claims (15)

A rotating electrical machine (100) operable in at least an alternator mode to power a motor vehicle,
-The rear bearing (4);
The rotor (1) fixed to the rotating shaft (2) supported at least by the rear bearing (4);
A stator (3) surrounding the rotor (1), the stator (3) including an armature winding (7) including windings constituting a phase of the electric machine;
The rear bearing (4) comprises a side opening (4b) for the outlet of the cooling fluid and at least one axial opening (4a) for the inlet of the cooling fluid into the stator (3); ,
A power electronics circuit (15) electrically connected to the phase winding of the stator (3);
-A first surface on which the power electronics circuit (15) is mounted on one side and a second surface facing the first surface and oriented toward the rear bearing (4) A radiator (16) included on the other,
A flow path (17) for the flow of cooling fluid between the upper surface of the rear bearing (4) oriented towards the radiator (16) and the second surface of the radiator (16); ,
In rotating electrical machines including
The second surface of the radiator (16) includes cooling fins (18, 18 ′, 18 ″, 18 ′ ″, 18 ″ ″);
At least one axial end of the fin (18) extends axially to at least the upper surface of the rear bearing (4);
Rotating electrical machine characterized by that. At least one fin (18, 18 '''') includes a portion (182) located inside the axial opening (4a) of the rear bearing (4),
The rotating electric machine according to claim 1. The fin (18 '''') extends only opposite the axial opening (4a) of the rear bearing (4),
The rotating electric machine according to claim 1, wherein the rotating electric machine is provided. The at least one fin (18) further includes a portion (181) facing the solid top surface of the rear bearing (4).
The rotating electrical machine according to any one of claims 1 to 3, wherein And further including at least one second fin (18 '') disposed opposite the axial opening (4a) of the rear bearing (4) and spaced from the upper surface of the rear bearing (4).
The rotary electric machine according to any one of claims 1 to 4, wherein the rotary electric machine is provided. The axial opening (4a) of the rear bearing (4) is the first and second lateral edges (41, 42), and the first lateral edge (41) is the second lateral edge. First and second side edges (41, 42) that are closer to the axis (X) of the rotor (1) than the edge (42), and the first side edges (41) Two other end edges (43, 44) connecting the second side edge (42),
The second fin (18 '') is one of the fins closest to one of the two end edges (43, 44);
The rotating electrical machine according to claim 5. The rear bearing (4) includes at least one deflector (24) disposed at the outlet of a side opening (4b) of the rear bearing (4).
The rotary electric machine according to any one of claims 1 to 6, wherein A protective cover (11) covering the power electronics circuit (15) and the radiator (16);
A rotary electric machine according to any one of claims 1 to 7, characterized in that The protective cover (11) includes at least one end raised to form the deflector (24),
The rotating electric machine according to claim 7 or 8, characterized in that. The protective cover (11) includes at least one axial opening (11b) for the passage of the fluid,
The rotary electric machine according to claim 8 or 9, characterized in that. The radiator (16) includes at least one main opening (16a) for passage of the rotating shaft (2) and the rear bearing from the axial opening (11b) of the cover (11). At least one vent opening (16b) allowing flow into the axial opening (4a) of (4),
The rotary electric machine according to claim 10. The radiator (16) includes a plurality of ventilation openings (16b).
The rotating electrical machine according to claim 11. At least one vent opening (16b) extends over a circular portion around the rotating shaft (2);
The rotary electric machine according to claim 11 or 12, characterized in that A position sensor (23) disposed around the rotating shaft (2) and at least partially closing the main opening (16a);
The rotary electric machine according to any one of claims 11 to 13, characterized in that: The position sensor (23) is a resolver that closes the main opening (16a) along the entire circumference of the rotating shaft (2).
The rotating electrical machine according to claim 14.

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