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
  • H02K1/02—Details of the magnetic circuit characterised by the magnetic material
• • 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
  • H02K1/20—Stationary parts of the magnetic circuit with channels or ducts for flow of cooling medium
• • 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
  • H02K9/197—Arrangements for cooling or ventilating for machines with closed casing and closed-circuit cooling using a liquid cooling medium, e.g. oil in which the rotor or stator space is fluid-tight, e.g. to provide for different cooling media for rotor and stator

Definitions

• the present invention relates to a rotating electric machine provided with a cooling chamber.
• the invention finds a particularly advantageous, but not exclusive, application with the rotating electrical machines equipping motor vehicles.
• a rotating electrical machine comprises a stator and a rotor secured to a shaft.
• the rotor may be integral with a driving and / or driven shaft and may belong to a rotating electric machine in the form of an alternator, an electric motor, or a reversible machine capable of operating in both modes.
• the stator is mounted in a housing configured to rotate the shaft, for example by means of bearings.
• the rotor comprises a body formed by a stack of sheet metal sheets held in the form of a bundle by means of a suitable fixing system, such as rivets axially passing through the body of the rotor right through.
• the rotor comprises poles formed for example by permanent magnets housed in cavities formed in the magnetic mass of the rotor, as described for example in document EP0803962.
• the poles are formed by coils wound around the arms of the rotor.
• the stator comprises a body formed by a stack of thin sheets forming a ring, the inner face of which is provided with notches open inwardly to receive phase windings.
• the phase windings are obtained for example from a continuous wire covered with enamel or pins welded together. These windings are polyphase windings connected in star or delta, the outputs of which are connected to an electronic control module comprising a power inverter.
• document WO2017216488 teaches the production of a cooling chamber arranged around the stator.
• a cooling liquid such as water, is intended to circulate in the chamber to extract the calories from the stator generated by the passage of currents in the winding.
• the cooling chamber is delimited on the one hand by an outer periphery of one of the bearings of the housing and on the other hand by an internal periphery of the other bearing of the housing.
• the stator body is shrunk with an internal periphery of one of the bearings, which constitutes a complex and expensive operation.
• such a configuration is bulky due to the radial superposition of the walls of the bearings to form the cooling chamber.
• the present invention aims to effectively remedy these drawbacks by providing a rotary electrical machine, in particular for a motor vehicle, comprising:
• stator comprising a stator body and a winding, said stator body comprising a yoke and teeth coming from an internal periphery of the yoke,
• the cooling chamber being delimited at least partly on the one hand by an outer periphery of the yoke of the stator body and on the other hand by a periphery internal bearing.
• the invention thus makes it possible to eliminate one of the bearings to form the cooling chamber, which makes the assembly more compact and has an economic character.
• the fact that at least the outer portion of the cylinder head is made of a magnetic composite material makes it possible to guarantee the tightness of the cooling chamber with respect to a stator body conventionally made entirely of laminated sheets.
• the invention makes it possible to eliminate the hooping step, so that the rotary electric machine is easier to produce.
• the stator body is made entirely from a composite magnetic material.
• the stator body comprises a first part formed by an internal portion of the yoke and the teeth and a second part formed by the outer portion of the yoke made of a composite magnetic material.
• the external portion of the cylinder head is molded around the internal portion of the cylinder head.
• the outer portion of the cylinder head is fixed to the internal portion of the cylinder head, in particular by fitting or gluing.
• the outer portion of the cylinder head comprises at least one groove intended to receive a seal.
• the outer portion of the cylinder head comprises a shoulder constituting an axial end wall of the cooling chamber.
• the internal periphery of the bearing comprises a shoulder constituting an axial end wall of the cooling chamber.
• the internal periphery of the bearing has a shoulder constituting an axial positioning stop for an axial end of the stator body.
• said rotating electrical machine comprises a dividing wall between a cooling liquid inlet and a cooling liquid outlet.
• a thickness of the external portion of the cylinder head is between 2mm and 4mm and is preferably of the order of 3mm.
• Figure 1 is a longitudinal sectional view of a first embodiment of a rotary electrical machine according to the present invention.
• Figure 2 is an exploded perspective view of the rotary electrical machine of Figure 1;
• Figure 3 is a perspective view of the stator of the rotary electrical machine of Figure 1;
• Figure 4 is a longitudinal sectional view of a second embodiment of a rotary electrical machine according to the present invention.
• Figure 5 is a perspective view of the stator of the rotary electrical machine of Figure 4.
• Figure 1 shows a rotating electrical machine 10 comprising a polyphase stator 1 1 surrounding a rotor 12 mounted on a shaft 13 of axis X corresponding to the axis of the electric machine 10.
• the stator 1 1 surrounds the rotor 12 with the presence of an air gap between the internal periphery of the stator 11 and the external periphery of the rotor 12.
• the electric machine 10 also comprises a front bearing 15 and a rear bearing 16 each provided with a housing 17 intended to receive a means of guiding the shaft 13 in rotation, such as a ball bearing.
• the front bearing 15 is located on the side of the output of the shaft 13 intended to cooperate with an external element of the machine (belt system, gear, or other), while the rear bearing 16 is located on the side opposite to the output of the shaft 13.
• the rear bearing 16 comprises a portion 21 of transverse orientation relative to the axis X centrally comprising the housing 17 of a bearing 19 and from which an annular portion comes 22 axially oriented having an axial length at least equal to that of the stator 1 January.
• the front bearing 15 comprises a transverse portion 23 centrally comprising a housing 17 of a bearing 19 from which an annular portion 24 axially shorter than the annular portion 22 of the rear bearing 16.
• the front bearing 15 forms a cover. intended to close the open end of the rear bearing 16.
• fixing members 26, such as screws or rivets cooperate with projecting lugs 27 produced on the outer periphery of the front bearing 15 and of the rear bearing 16.
• the configurations of the front bearing 15 and of the rear bearing 16 could of course be reversed, that is to say that the rear bearing 16 could act as a cover for the front bearing 15.
• the rotor 12 comprises, in a manner known per se, a body 29 in the form of a pack of sheets. Permanent magnets 30 are implanted in cavities of the body 29, as shown in FIGS. 1 and 4.
• the permanent magnets 30 may be of rare earths or of ferrite depending on the applications and the desired power of the electrical machine 10.
• the rotor 12 comprises two flanges 31 each pressed against an axial end face of the rotor 12. These flanges 31 provide axial retention of the magnets 30 and serve, where appropriate, to balance the rotor 12.
• the stator 1 1 comprises a body 33 as well as a coil 34.
• the stator body 33 is provided with teeth 35 from an internal periphery of a cylinder head 37 annular with axial orientation relative to the X axis.
• the teeth 35 and the yoke 37 have a magnetic function, insofar as the magnetic flux of the electric machine passes through these elements to ensure its operation.
• the teeth 35 define two by two of the notches 40 for mounting the coil 34 of the stator January 1. Thus, two successive notches 40 are separated by a tooth 35.
• the notches 40 open axially into the axial end faces and radially towards the inside of the stator body 33.
• the stator body 33 is made in two parts, namely a first part 33.1 formed by an internal portion 37.1 of the cylinder head 37 from which the teeth 35 and a second part 33.2, independent of the first part 33.1, formed by an outer portion 37.2 of the cylinder head 37.
• the first part 33.1 namely the whole "internal portion 37.1 of the cylinder head 37 and teeth 35" consists of a bundle of sheets produced by a stack of sheets of sheets held in the form of a package by means of a suitable fixing system, such as rivets.
• the second part 33.2 namely the outer portion 37.2 of the cylinder head 37, is made of a composite magnetic material, or SMC material for "Soft Magnetic Composite” in English).
• This material contains powder of ferromagnetic material, such as steel powder, the particles of which are bonded with an insulating material, for example a polymer material resistant to high temperatures.
• the outer portion 37.2 of the cylinder head 37 is preferably molded around the internal portion 37.1 of the cylinder head 37.
• the outer portion 37.2 of the cylinder head 37 is fixed to the internal portion 37.1 of the cylinder head 37, in particular by fitting or gluing.
• the outer portion 37.2 of the cylinder head 37 has a thickness between 2mm and 4mm and is preferably of the order of 3mm.
• the internal portion 37.1 of the cylinder head 37 has a thickness of between 1 5mm and 3mm, and is preferably of the order of 2mm.
• the coil 34 shown in Figures 1 and 2 comprises a set of phase windings passing through the notches 40 and forming buns extending projecting on either side of the stator body 33.
• the coil 34 is made from conductive elements in the form of pins connected together for example by welding. These windings are for example three-phase or double three-phase windings connected in star or delta.
• a cooling chamber 41 is arranged around the stator body 33, as shown in FIG. 1.
• the cooling chamber 41 may advantageously have an annular shape.
• the cooling chamber 41 is provided with an inlet 42 and a cooling liquid outlet 43 (see FIG. 2) to allow circulation of the cooling liquid inside the cooling chamber 41 around the stator body 33.
• the cooling chamber 41 is delimited at least in part on the one hand by an outer periphery of the yoke 37 of the stator body 33 and on the other hand by an inner periphery of one of the bearings. In this case, the cooling chamber 41 is delimited at least in part on the one hand by an outer periphery of the outer portion 37.2 of the cylinder head 37 and on the other hand by an inner periphery of the rear bearing 16.
• the cooling liquid such as water or oil or any other liquid with a high heat transfer capacity suitable for the application, being in direct contact with the stator body 33, the extraction of calories generated by the current flowing in the coil 34 is optimal.
• the outer portion 37.2 of the cylinder head 37 comprises a shoulder 45 defined by a difference in external diameter constituting an axial end wall of the cooling chamber 41.
• the rear bearing 16 comprises an internal periphery stepped in diameter having a shoulder 46 constituting the other axial end wall of the cooling chamber 41.
• the internal periphery of the rear bearing 16 also comprises a shoulder 47 constituting an axial positioning stop for an axial end of the stator body 33.
• the sealing of the cooling chamber 41 is provided by seals 49, in particular of the O-ring type, each arranged in a corresponding groove 50 formed in the outer portion 37.2 of the cylinder head 37.
• seals 49 may be provided in the internal periphery of the rear bearing 16.
• a wall 51 makes it possible to separate the inlet 42 of coolant and the outlet 43 of coolant in order to promote renewal of the coolant in the chamber 41.
• the stator body 33 is made entirely of a composite magnetic material.
• the stator 11 may include a coil 34 made from continuous son or pins as above, or from individual coils 53 wound around the teeth 35 of the stator 1 1 by means of a coil insulator 54, such as as shown in Figure 5.

Landscapes

• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Iron Core Of Rotating Electric Machines (AREA)
• Motor Or Generator Cooling System (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=67875687

Family Applications (1)

Country Status (5)

Family Cites Families (6)

• 2019
  • 2019-06-03 FR FR1905840A patent/FR3096844B1/fr active Active
• 2020
  • 2020-06-02 US US17/615,770 patent/US20220320922A1/en active Pending
  • 2020-06-02 WO PCT/EP2020/065229 patent/WO2020245122A1/fr unknown
  • 2020-06-02 CN CN202080041317.3A patent/CN113924717A/zh active Pending
  • 2020-06-02 EP EP20729080.0A patent/EP3977601A1/de active Pending

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