Classifications

• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K5/00—Casings; Enclosures; Supports
  • H02K5/04—Casings or enclosures characterised by the shape, form or construction thereof
  • H02K5/20—Casings or enclosures characterised by the shape, form or construction thereof with channels or ducts for flow of cooling medium
  • H02K5/203—Casings or enclosures characterised by the shape, form or construction thereof with channels or ducts for flow of cooling medium specially adapted for liquids, e.g. cooling jackets
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K1/00—Details of the magnetic circuit
  • H02K1/06—Details of the magnetic circuit characterised by the shape, form or construction
  • H02K1/12—Stationary parts of the magnetic circuit
  • H02K1/18—Means for mounting or fastening magnetic stationary parts on to, or to, the stator structures
  • H02K1/185—Means for mounting or fastening magnetic stationary parts on to, or to, the stator structures to outer stators
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K5/00—Casings; Enclosures; Supports
  • H02K5/04—Casings or enclosures characterised by the shape, form or construction thereof
  • H02K5/16—Means for supporting bearings, e.g. insulating supports or means for fitting bearings in the bearing-shields
  • H02K5/173—Means for supporting bearings, e.g. insulating supports or means for fitting bearings in the bearing-shields using bearings with rolling contact, e.g. ball bearings
  • H02K5/1732—Means for supporting bearings, e.g. insulating supports or means for fitting bearings in the bearing-shields using bearings with rolling contact, e.g. ball bearings radially supporting the rotary shaft at both ends of the rotor
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K9/00—Arrangements for cooling or ventilating
  • H02K9/19—Arrangements for cooling or ventilating for machines with closed casing and closed-circuit cooling using a liquid cooling medium, e.g. oil
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K5/00—Casings; Enclosures; Supports
  • H02K5/04—Casings or enclosures characterised by the shape, form or construction thereof
  • H02K5/15—Mounting arrangements for bearing-shields or end plates
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K7/00—Arrangements for handling mechanical energy structurally associated with dynamo-electric machines, e.g. structural association with mechanical driving motors or auxiliary dynamo-electric machines
  • H02K7/10—Structural association with clutches, brakes, gears, pulleys or mechanical starters
  • H02K7/116—Structural association with clutches, brakes, gears, pulleys or mechanical starters with gears

Definitions

• the present invention relates to a rotating electrical machine with improved cooling.
• the invention finds a particularly advantageous, but not exclusive, application with high power reversible electrical machines that can operate in alternator mode and in motor mode coupled with a host element such as a gearbox.
• the rotating electrical machines comprise a stator and a rotor secured to a shaft.
• the rotor may be integral with a driving shaft and / or driven and may belong to a rotating electrical machine in the form of an alternator, an electric motor, or a reversible machine that can operate in both modes.
• the stator is mounted in a housing configured to rotate the shaft on bearings by bearings.
• the rotor comprises a body formed by a stack of sheets of sheet metal held in pack form by means of a suitable fastening system.
• the rotor comprises poles formed for example by permanent magnets housed in cavities formed in the magnetic mass of the rotor. Alternatively, in a so-called "salient" poles architecture, the poles are formed by coils wound around rotor arms.
• the stator comprises a body consisting of a stack of thin sheets forming a ring, whose inner face is provided with notches open inwardly to receive phase windings. These windings pass through the notches of the stator body and form buns protruding from both sides of the stator body.
• the phase windings are obtained for example from a continuous wire covered with enamel or from conductive elements in the form of pins connected together by welding. These windings are polyphase windings connected in star or delta whose outputs are connected to an electrical control module.
• a reversible power machine of high power is coupled to the vehicle gearbox.
• the electric machine is then able to operate in an alternator mode to provide, in particular, power to the battery and to the on-board vehicle network, and in a motor mode, not only to start the engine, but also to participate pulling the vehicle alone or in combination with the engine.
• the machine is positioned inside the volume defined by the gearbox housing so that a pinion carried by the shaft of the machine cooperates with a corresponding pinion of the gearbox.
• the document WO2014 / 032876 describes the production of a cooling duct formed between the casing and the stator. Furthermore, the document DE102012022453 describes an electric machine provided with cooling ducts and a corresponding channel for supplying a fluid. However, the realization of such channels is difficult, insofar as it requires the implementation of many machining operations. In addition, the thermal performance of the machine remains limited.
• the present invention aims to improve the cooling of such a machine while simplifying its design.
• the invention proposes a rotary electrical machine, in particular for a hybrid motor vehicle, said rotating electrical machine being intended to bathe in a cooling liquid contained in an internal volume of a host element, such as a gearbox. of a hybrid motor vehicle, said rotating electric machine comprising:
• a housing comprising a front bearing and a rear bearing
• stator comprising a stator body and surrounding said rotor with the presence of an air gap, said stator body having an external face, characterized in that said stator body is kept clamped between said front bearing and said rear bearing, and what said housing has a an opening extending between said front bearing and said rear bearing, so as to leave a portion of said outer face of said stator body in contact with said coolant contained in said internal volume of said host member.
• the invention thus makes it possible, by virtue of the direct contact between the external face of the stator and the cooling liquid, to improve the cooling performance of the electric machine and this with a yield much greater than that of machines provided with pipes ensuring only an internal circulation of coolant.
• the construction of the housing is simplified, insofar as it is easy to provide the opening between the two bearings without additional machining operation.
• the electric machine is an alternator or alternator-starter motor vehicle.
• each contact zone there is a contact zone between said stator body and each of the front and rear bearings, each contact zone extending over the circumferential periphery of said stator body.
• said opening extends along an entire circumference of said stator body.
• said opening extends over at least 30% of an axial length of said stator body, preferably at least 60%, for example over at least 80% of said axial length.
• the front bearing and the rear bearing are metallic, for example made of aluminum.
• stator body is held tight between said front and rear bearings by means of fasteners, in particular by tie rods.
• the fasteners extend axially radially outwardly of the stator body and outside the rotor body.
• said fasteners extend axially and are fixed in ears from an outer periphery of the front and rear bearings.
• said rotating electrical machine comprises at least one indexing means in rotation of at least one of said bearings relative to said stator body.
• said indexing means comprises a rib extending axially on the outer face of said stator body and intended to cooperate by at least one of its ends with a groove of corresponding shape formed in one of the bearings.
• said stator body comprises a stack of sheets of sheet metal, each sheet metal sheet having a radial protuberance, said rib being made by axial alignment of said protuberances.
• at least one of the bearings comprises a bearing support disposed on an outer radial surface of said bearing, said bearing support being intended to receive a bearing of a shaft of the host element.
• At least one of the bearings comprises a fixing interface for fixing said rotating electrical machine on said host element.
• said shaft comprises a central bore and at least two radially opening orifices disposed axially on either side of said rotor for diffusing the cooling liquid inside said shaft.
• rotating electric machine The liquid circulating inside the machine may be different from that cooling the stator.
• said rotating electrical machine comprises two flanges each positioned against an axial end face of said rotor, each flange being provided with at least one projection member arranged to centrifugally project cooling liquid arriving on the face of the rotor. corresponding end towards winding buns.
• each contact zone there is a contact zone between said stator body and each of the front and rear bearings, each contact zone extending over a circumferential periphery of said stator body, so that the cooling liquid in contact with said outer face of said stator body can not penetrate inside said rotating electrical machine.
• said rotating electrical machine comprises a single bearing carried by one of said bearings.
• said rotating electrical machine comprises a pin winding. This type of winding is particularly suitable for reversible electrical machines given the necessary torque when the electric machine is in motor mode.
• the machine comprises a buried magnet rotor.
• the machine is thus devoid of brush, which allows its immersion in the oil bath contained in the host element.
• a host element comprising a casing delimiting an internal volume filled with a coolant
• the host element is a motor vehicle gearbox or a motor vehicle gearbox.
• Figure 1 is a perspective view of a rotating electrical machine according to the present invention
• Figure 2 is a perspective view of the rotating electrical machine of Figure 1 without the housing;
• Figure 3 is a longitudinal sectional view of the rotating electrical machine according to the present invention
• Figure 4 is a schematic representation of an assembly of the rotary electric machine of Figure 1 with a gearbox
• Figure 5 is a top view of a stator of the rotating electrical machine according to the present invention.
• Figures 6a and 6b are perspective views at different angles of the front bearing of the rotating electrical machine according to the invention.
• Figure 7 is a perspective view of the rear bearing of the rotating electrical machine according to the invention.
• FIGS. 1, 2 and 3 show a rotating electrical machine 10 comprising a polyphase stator 1 1 surrounding a rotor 12 mounted on a shaft 13 of axis X.
• the stator 11 surrounds the rotor 12 with the presence of an air gap 15 between the inner periphery of the stator January 1 and the outer periphery of the rotor 12.
• the stator January 1 is mounted in a housing 14 provided with a front bearing 17 and a rear bearing 18 whose configuration is described in more detail below .
• This electric machine 10 is intended to be coupled to a clearly visible gearbox 16 in FIG. 4 belonging to a traction drive of motor vehicle.
• the machine 10 is able to operate in an alternator mode to supply, in particular, energy to the battery and to the on-board vehicle network, and in a motor mode, not only to start the engine of the vehicle, but also to participate in pulling the vehicle alone or in combination with the engine.
• the power of the machine 10 may be between 15kW and 50kW.
• the rotor 12 comprises a body 19 in the form of a bundle of sheets.
• Permanent magnets 20 are implanted in cavities 21 of the body 19.
• the magnets 20 may be of rare earth or ferrite depending on the applications and the desired power of the machine 10.
• the poles of the rotor 12 may be formed by coils .
• the machine 10 is thus devoid of brush, which allows its immersion in the oil bath contained in the gearbox 16, as explained below.
• the stator January 1 comprises a body 23 constituted by a bundle of sheets and a coil 24.
• the body 23 is formed by a stack of sheet sheets 82 independent of each other and maintained in the form of a package by means of a suitable fastening system.
• the configuration of such a body 23 is called a "round sheet package" as opposed to a body 23 obtained by machining a helically wound continuous sheet to obtain the different sheet layers of the package.
• the body 23 is delimited by an internal cylindrical face 25, an outer cylindrical face 26, as well as by two axial end faces 27, 28 (see FIG. 2).
• This body 23 is provided with teeth 31 extending from an inner periphery of an annular yoke 32 and defining two by two notches 33 for mounting the winding 24 of the stator January 1.
• two successive notches 33 are separated by a tooth 31.
• the notches 33 open axially into the end faces 27, 28 and radially into the internal cylindrical face 25 of the stator body 23.
• the insulation between the internal faces of the slots 33 and the coil 24 may for example be achieved by means of insulating paper.
• the coil 24 comprises a set of phase windings passing through the notches 33 and forming bunches 36, 37 projecting on either side of the stator body 23 (see FIG. 2).
• the phase windings are obtained here from conductive elements in the form of pins connected together for example by welding. These windings are, for example, three-phase windings connected in a star or in a triangle.
• the outputs of the phase windings are connected to an electrical control module.
• the electric machine 10 is cooled by means of a cooling circuit 41 shown in FIG. 3 allowing the flow of a cooling liquid, in this case oil, inside the machine 10.
• the cooling circuit 41 comprises a pump 42 conveying the oil in a central axial bore 43 formed in the shaft 13 and to at least two orifices 44 opening radially and arranged axially on either side of the rotor 12 for spread the coolant inside the machine 10.
• the cooling circuit 41 operates in a closed loop, so that the oil is taken by the pump 42 in a reservoir 45 and is recovered after circulation in the machine 10 in the tank 45.
• the reservoir 45 may correspond to the volume of oil contained in the gearbox 16 as explained below.
• the rotor 12 comprises two flanges 48 each clad against an axial end face of the rotor 12. These flanges 48 provide axial retention of the magnets 20 inside the cavities 21 and also serve to balance the rotor 12.
• Each flange 48 may advantageously be provided with at least one projection member 49, constituted by a blade, arranged to project by centrifugation the cooling liquid arriving on the corresponding end face towards the buns of the winding 36, 37.
• the machine 10 is positioned inside the volume 52 delimited by a casing 53 of the gearbox 16 filled with coolant 54.
• the fluid of cooling 54 is constituted by the oil used for the lubrication of the various mechanical components of the gearbox 16 and to carry out the cooling of the electric machine 10.
• the volume 52 of the coolant surrounds at least partly the electric machine 10
• the liquid 54 contained in the gearbox 16 is used for internally cooling the machine 10 via the cooling circuit 41.
• a different liquid from that contained in the gearbox could be used for the internal cooling of the machine 10.
• the electric machine 10 is disposed in the volume 52, so that the pinion 57 carried by the shaft 13 cooperates with a pinion 58 corresponding to the gearbox 16.
• the front bearing 17 is provided with an opening 60 to allow the passage of the shaft 13.
• the rear bearing 18 carries a bearing 61, such a bearing ball or needle for the rotational mounting of the shaft 13.
• the bearing 61 is mounted in an annular sleeve 63 visible in Figure 7 and bears against a bottom 64 from an inner periphery of the sleeve 63.
• the free end of the shaft 13 protruding from the housing 14 of the electric machine 10 is rotatably mounted via a bearing 62 carried by the housing 53 of the gearbox 16 (see Figure 2).
• the machine 10 has a single bearing 61, which facilitates the mounting of the machine 10 inside the gearbox 16 and reduces the risk of hyperstatism of the assembly.
• the casing 14 has an opening 65 extending between the front bearing 17 and the rear bearing 18, so as to leave a portion of the outer face 26 of the stator body 23 in contact with the cooling liquid 54 contained in the internal volume. 52 of the casing 53.
• the opening 65 extends along the entire circumference of the stator body 23 and over a length L1 equal to at least 30% of the axial length L2 of the stator body 23, preferably at least 60%, for example at least 80% of the length L2.
• the sum of the axial lengths of the front L3 and rear L4 bearings is less than the total axial length L5 of the electric machine 10.
• the stator body 23 is held tight by fasteners 67, in particular by tie rods.
• These tie rods 67 extend axially and cooperate with lugs 68 coming from the outer periphery of the front and rear bearings 17 shown in FIGS. 1, 6a, 6b, and 7.
• the front bearing 17 may comprise a bearing support 71 arranged on an outer radial surface of the front bearing 17.
• This bearing support 71 formed by an annular wall projecting from the outer surface of the front bearing 17, is intended to receive a bearing (not shown) of a Gearbox shaft 16.
• the front bearing 17 has an attachment interface 72 for fixing the machine 10 to the gearbox 16.
• the fixing interface 72 comprises a plurality of lugs 75 projecting from the outer periphery of the front bearing 17.
• the lugs 75 are perforated to allow the passage of fastening screws (not shown) intended to cooperate with bores tar formed in walls of the housing 53 of the gearbox 16.
• an indexing means 78 for rotating the bearings 17, 18 with respect to the stator body 23.
• the indexing means 78 is constituted in this case by a plurality of ribs 79 extending axially on the outer face 26 of the stator body 23 and intended to cooperate at their ends with grooves 80 of corresponding shape formed in the bearings 17 and 18.
• each sheet metal sheet 82 of the stator body 23 comprises a plurality of radial protuberances 83.
• Each rib 79 is made by axial alignment of the corresponding protuberances 83. .
• the rotational indexing is ensured between the stator body 23 and only one of the bearings 17 or 18.
• the bearing support 71 is provided on the rear bearing 18.
• the rear bearing 18 comprises at least one attachment interface 72 for fixing the machine 10 to the host element 16.
• the single bearing 61 is carried by the front bearing 17.
• the host element is not a gearbox but a clutch with which the electric machine 10 is coupled.
• the machine 10 does not have an internal cooling circuit 41 , cooling being ensured only by contacting the stator 23 with the coolant contained in the host element.

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• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Motor Or Generator Cooling System (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (1)

Family

ID=55862951

Family Applications (1)

Country Status (4)

Cited By (6)

Families Citing this family (1)

Citations (4)

Family Cites Families (7)

• 2016
  • 2016-01-15 FR FR1650306A patent/FR3046889A1/fr not_active Withdrawn
  • 2016-12-13 DE DE112016006235.4T patent/DE112016006235T5/de not_active Withdrawn
  • 2016-12-13 WO PCT/FR2016/053373 patent/WO2017121930A1/fr active Application Filing
  • 2016-12-13 CN CN201680078029.9A patent/CN108702040A/zh active Pending

Patent Citations (4)

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