Classifications

• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K49/00—Dynamo-electric clutches; Dynamo-electric brakes
  • H02K49/02—Dynamo-electric clutches; Dynamo-electric brakes of the asynchronous induction type
  • H02K49/04—Dynamo-electric clutches; Dynamo-electric brakes of the asynchronous induction type of the eddy-current hysteresis type
• • 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
  • H02K1/22—Rotating parts of the magnetic circuit
  • H02K1/32—Rotating 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
  • H02K3/00—Details of windings
  • H02K3/04—Windings characterised by the conductor shape, form or construction, e.g. with bar conductors
  • H02K3/24—Windings characterised by the conductor shape, form or construction, e.g. with bar conductors with channels or ducts for cooling medium between the conductors
• • 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
  • 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

Definitions

• the invention relates to a section of a cooling pipe for a rotary electric machine, in particular for a rotary electric machine fitted to a motor vehicle, as well as a rotary electric machine comprising such a section of a cooling pipe.
• the need for particularly well-functioning cooling is not limited to the heat engine by means of which the motor vehicle is driven, but also relates to auxiliary equipment such as an alternator, or an electromagnetic retarder intended for slow down a vehicle drive shaft. While equipment, such as an alternator, is cooled by a cooling water circuit only in cases where air cooling, less restrictive to install, turns out to be insufficient, the larger machines intended for undergoing greater efforts are almost always cooled by a liquid circulating in a cooling circuit.
• Such a fluid is for example water, it being understood that this water comprises at least one additive such as an anti-freeze, for example glycol. It circulates in a pipe constituting, together with a heat exchanger, a cooling circuit.
• machines such as internal combustion engines are provided with a cooling channel consisting of a set of highly branched conduits for passing the cooling fluid almost to all corners of the machine
• machines rotary electrical devices such as an electromagnetic retarder must be cooled by means of a simple pipe intended to surround the cooling machine, for example a pipe having the general shape of a propeller.
• the invention is not limited to a certain type of machine or to a certain type of pipe. However, to simplify the description, the invention will be presented and defined, as to the macine to be cooled, to.
• the second embodiment of the section relates to a circuit comprising essentially straight and parallel conduits between them.
• An electromagnetic retarder and electrical supply means for the retarder form an assembly generally comprising a stator traversed by the shaft and a rotor intended to be assembled with the shaft so as to have an external cylindrical face nearby ⁇ ne internal cylindrical face of the stator with a thin air gap interposed between the rotor and the stator.
• the rotor comprises an inductor with coils and electrical wires, capable of generating a magnetic field in an annular ferromagnetic part of the stator, which forms the armature and which is associated with a cooling circuit with a fluid such as water containing an additive as indicated above.
• a rotary electrical machine such as, for example, an electromagnetic retarder, can therefore be considered very schematically as a device in two parts: the first part is constituted by the rotor which is in the form of a solid core intended for be attached to a drive shaft of a motive force which one seeks to brake, and a stator having the shape of a cylindrical box surrounding the rotor.
• the annular piece of ferromagnetic material consists of a cylindrical drum surrounding the inductor with the interposition of a cylindrical air gap.
• a cooling pipe is formed which runs directly along the face of the annular piece of ferromagnetic material, which is opposite to the air gap.
• the section of this pipeline which is in direct contact with the cooling machine, extends, for example, along a helix around the annular piece of ferromagnetic material. It is terminated at each of its two ends by an inlet and outlet connection respectively.
• the pipe section surrounding the cooling machine forms, in a motor vehicle fitted with such a rotary machine, together with an external heat exchanger, the remainder of the cooling pipe and a drive pump, a cooling circuit allowing dissipate a fairly large amount of heat to the outside.
• this cooling circuit of the rotary machine is connected to the cooling circuit of the engine of the vehicle.
• the inlet and outlet connections of the cooling pipe section to the cooling circuit are formed by nozzles arranged perpendicularly or inclined to the cooling machine.
• the coolant must circulate in the circuit at a fairly high speed.
• the circulation speed of the cooling fluid is increased.
• better convection of heat is obtained by the generation of turbulence in the flow of the fluid.
• the traditional arrangement of the couplings generates harmful turbulences which therefore do not contribute to the increase in the cooling capacity of the fluid, but on the contrary reduce it by increasing the pressure losses, by pressure, of the cooling circuit and thus reducing the fluid flow, therefore its speed.
• the pressure losses are due to the friction of the fluid on the surface, linked to turbulence, to the separation of the fluid linked to the gradual widening of the circuit pipe, to shocks to the walls of the pipe if the flow takes place. with incidence, and at the change of direction of the flow.
• the object of the invention is to propose means making it possible to improve the cooling of the rotary machine by reducing the pressure drops in the fluid circuit.
• Order of 1 »invention is achieved with a section of a cooling duct for a rotating electrical machine, the Line section comprising at least one pipe laid along at least a portion of the machine to be cooled, as well as '' at least one inlet fitting and at least one outlet fitting for a cooling fluid between which the duct (s) are closed.
• the or each circuit has an input axis and an output axis.
• the inlet fitting (s) and the outlet fitting (s) are each oriented at least approximately along the orientation of the inlet axis or the 'corresponding output axis of the circuit.
• the inlet and outlet fittings have, like the circuits, an inlet axis and an outlet port.
• the inlet connection (s) and the outlet connection (s) have, whatever 'in either their shape, all along their longitudinal extent, a constant area of their passage sections. Thanks to this arrangement of the invention, the cooling fluid immediately enters the correct direction, that is to say essentially without change of direction, in the section of the cooling pipe and therefore does not generate turbulence by flow deviation.
• This improvement, which the invention brings to the cooling system of rotary machines is particularly advantageous for the cooling of highly stressed rotary machines such as electromagnetic retarders used for industrial vehicles.
• the best orientation of the flow of the cooling fluid arriving via the inlet connection of the pipe section is that which corresponds to the orientation of the axis or of the median plane of the start of the duct.
• the best orientation of the flow of cooling fluid leaving via the outlet connector of the pipe section is that which corresponds to the orientation of the axis or of the median plane of the end of the duct.
• the orientation described above of the inlet and outlet connections of the section according to the invention also applies equally to a section comprising several essentially straight conduits and arranged at least approximately parallel to the longitudinal axis of the machine.
• the inlet and outlet connections are oriented at least approximately parallel to the longitudinal axis of the cooling machine and at the same time coaxially with respect to the duct to which they are assigned.
• the inlet and outlet fittings are oriented respectively along a tangential inlet plane and a tangential outlet plane, each of them passing through a corresponding circumferential inlet or outlet area of the helical duct of the section.
• the inlet fitting and the outlet fitting are arranged, in an axial view of the rotary machine â . cool, on the same side of the rotary machine and with a slight angular offset between the two fittings.
• this arrangement makes it possible to orient the rotary machine equipped with the pipe section of the invention in such a way that the inlet and outlet connections are for example located in the upper part of the cooling pipe.
• the advantage of the orientation of the inlet and outlet fittings of a pipe according to the invention is more particularly remarkable When the pipe section has an essentially helical shape and is formed by one or more successive chambers, each of which does not have only one turn between its respective entry and exit.
• the helical duct is free of any wall intended to divide the duct into a plurality of turns, that is to say when the duct constitutes a single volume, it is particularly important to obtain a flow of the fluid turbulence-free cooling originating from interference between the incoming and outgoing flows and creating dead zones for cooling with the fluid swirling on site.
• the inlet and outlet orientation, according to the invention, of the flow of the fluid cooling in a helical duct with a single turn is advantageously obtained by forming it by two complementary walls, an outer wall and an inner wall, the wall inner being formed by the outer surface of the stator of the cooling machine, and the outer wall being formed by a single piece joining in it the pipe section with inlet fitting and outlet fitting.
• a helical conduit with two adjacent single turns can be formed by a single piece forming an outer wall having a common inlet connection and two separate outlet fittings or two separate inlet fittings and a common outlet fitting.
• This unique piece then includes two progressive walls, one for each turn.
• the number of inlet and outlet fittings and / or the number of walls and turns can be greater than two. All the above characteristics are to be considered separately or in combination.
• the object of the invention is also achieved with a rotary machine comprising a section of cooling pipe as described above.
• the electric machine is beforehand an electromagnetic retarder.
• FIG. 1 diagrammatically represents a rotary machine comprising a liquid cooling circuit in which the coolant inlet and outlet conduits are connected radially to the outside of a coolant jacket
• Figure 2 shows as a first embodiment of the section according to the invention a cross section of a section of a cooling pipe in the form of a jacket of cooling fluid with helical circuit
• Figure 3 shows the jacket of coolant of Figure 2 in a perspective view
• Figure 4 and Figure 5 show the shape and cross section of a connector of the section of Figure 2
• Figures 6 and 7 show the inlet fittings and output variant embodiments of the section of Figure 2
• Figure 8 shows a variant of the cooling fluid casing of Figure 3
• Figure 9 mon be the volume of fluid in the envelope of cooling fluid of FIG.
• FIGS. 10 and 11 show a second embodiment of the section according to the invention.
• FIG. 1 schematically recalls the current design, before the present invention, rotary electrical machines cooled by a fluid, for example an electromagnetic retarder cooled by a water circuit.
• a gearbox 1 with an output shaft which is integral in rotation by means of a speed multiplier, as described in document O2004 / 017502, with the shaft of a rotor d an electromagnetic retarder 2.
• This retarder 2 is cooled by a cooling circuit 5 comprising a water supply pipe 3 and a water flow pipe 4.
• the pipes 3 and 4 respectively arrive and leave on the circuit cooling water arranged inside the retarder 2 and constitutes by a helical duct, at an essentially right angle with respect to the direction of the flow of water in the helical circuit.
• a cooling circuit according to the invention shown in FIG.
• a section of a cooling pipe in the form of a helical duct 11 intended to surround a stator 14 and a rotor 15 of the rotary cooling machine.
• the conduit 11 has one or several turns surrounding the cooling machine, with an inlet connection 12 and an outlet connection 13 tangential.
• This duct 11 is integral with the stator 14.
• the duct is carried by the stator 1.
• the characteristic "tangential” indicates that the fittings 12 and 13 are oriented each, the inlet fitting 12 in a circumferential inlet area Z1 and the outlet fitting 13 in a circumferential outlet area Z2 of the conduit 11, at least approximately along a tangent TI passing through the center of the area Z1 and at least approximately along a tangent T2 passing through the center of the area Z2.
• the centers of the zones Zl and Z2 are determined by radii RI and R2 ending on the circumference of the duct 11.
• the angular offset ⁇ between the arrival zones Zl and Z2 output which is favorably of the order of 20 ° to 30 °, but which can take any other value between 0 ° and 360 ° without departing from the principle of the present invention.
• the arrangement of the outlet connector 13 relative to the inlet connector 12 with a relatively small angular offset as indicated above corresponds to a configuration considered to be advantageous for embodiments where the helical duct 11 surrounding the rotary machine comprises only a single turn or a series of adjacent single turns. This arrangement has proved to be particularly effective, and in particular more efficient than the helical conduits having several turns.
• the helical duct comprises only a single turn or several adjacent single turns
• the portion of coolant considered travels, comparatively said, in the single turn or in each of the adjacent single turns, only the "first" turn and immediately leaves the helical duct.
• FIG. 3 represents in a perspective view an envelope of cooling fluid constituting the external wall which forms, together with the external surface of the stator 14 as internal wall, the helical duct 11 according to the invention.
• This view more particularly shows the circumferential extent of the inlet area of the inlet fitting 12 and of the outlet area of the outlet fitting 13.
• the location of the references Z1 and Z2 in this figure corresponds essentially at the tangential inlet of the inlet fitting 12 and of the tangential outlet of the outlet fitting 13.
• the inlet and outlet fittings 12, 13 are shaped so as to have, throughout their longitudinal extent, a constant area of their passage section, as shown schematically on Figures 4 and 5.
• Figure 3 also shows that the inlet area of the inlet fitting 12 and the outlet area where com mence the outlet fitting 13, are separated from one another by an evolutive wall M shaped so as to give the coolant a preferred direction of flow.
• the cooling fluid arrives in the zone Z1 with a fairly high speed and pressure and encounters a fluid of lower pressure exiting through the zone Z2. So that the exchange surface er ⁇ tre the incoming flow and the outgoing flow is relatively small and therefore does not favor a significant interaction between the two flows, it could nevertheless occur cgue the meeting between the two flows creates a zone of turbulence which severely affects the efficient flow of coolant. Part of the fluid flow could then pass directly from the arrival zone to the exit zone and somehow “short-circuit” the turn, that is to say to leave immediately, without making the complete turn of the cooling chamber. To avoid this, the progressive wall M separates the arrival zone Z1 from the exit zone Z2, the height of the wall M corresponding to the height of the helical conduit 11.
• FIG. 4 represents, the conduit 11 according to the invention with a inlet connector 12.
• the passage section of the inlet connector 12 is shown above the latter at four different locations to thereby demonstrate the change in the shape of the passage section while keeping the passage area constant.
• Figure 5 shows, schematically in a side view, the connector 12 and the start of the section 11.
• the passage section of the inlet connector 12 is shown next to the latter in three different places to demonstrate the change in the shape of the passage section while keeping the passage area constant.
• the section of the cooling pipe according to the invention can also consist of two or more adjacent single turns, as shown in FIGS. 6 and 7.
• FIGS. 6 and 7 show a section having two adjacent turns 11A. and 11B. The width of each of these turns is then only a corresponding part of the axial extent available for cooling the cooling machine.
• these unique turns are arranged and formed in such a way that each input connection 12A, 12B or each outlet connection 13A, 13B is in common of two adjacent turns 11A / 11B. This results in the combinations of turns, chosen for purely indicative and in particular nonlimiting, represented in FIGS. 6 and 7: FIG.
• FIG. 8 shows a variant embodiment of the cooling fluid envelope of FIG. 3, which essentially consists of two conduits extending respectively the inlet connector 12 and the outlet connector 13 so as to obtain a conduit inlet C12 oriented parallel to an outlet duct C13.
• FIG. 8 we partially see the fixing flange on a vehicle frame.
• Figure 9 shows the volume of fluid as it passes through the cooling fluid envelope shown in Figure 8. To simplify the identification of the different parts of the flow section, these have the same reference numbers as the corresponding parts of the cooling fluid envelope of FIG. 8.
• FIGS. 10 and 11 show another embodiment of the section according to the invention.
• This section is formed by conduits parallel to each other: and arranged parallel around the longitudinal axis of the cooling machine.
• the inlet 112 and outlet 113 connections which advantageously have a round cross section, are arranged coaxially with respect to each duct 111 to which they are assigned.
• the conduits 111 In order to form a closed envelope of coolant, that is to say completely surrounding the body of the cooling machine, the conduits 111 have a cross section of an annular sector.
• the invention is not limited to the embodiments described.
• the rotor shaft being able to be connected to the gearbox output shaft as described in document EP-A-0 331 559, or alternatively to the rear axle input shaft.
• the rotary electrical machine is alternatively an alternator with a liquid cooling circuit as described for example in document FR-A-2 780 571.
• This alternator can be reversible, in particular to constitute an electric motor in order to start the engine of the motor vehicle. .
• Such an alternator is called an alternator-starter.

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

Applications Claiming Priority (2)

Publications (1)

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ID=34896622

Family Applications (1)

Country Status (5)

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Family Cites Families (14)

• 2004
  • 2004-03-18 FR FR0402806A patent/FR2867914B1/fr not_active Expired - Fee Related
• 2005
  • 2005-03-17 CN CNA200580008587XA patent/CN1934767A/zh active Pending
  • 2005-03-17 EP EP05739417A patent/EP1738451A1/de not_active Withdrawn
  • 2005-03-17 WO PCT/FR2005/000650 patent/WO2005101618A1/fr not_active Ceased
  • 2005-03-17 US US10/598,938 patent/US20070188028A1/en not_active Abandoned

Non-Patent Citations (1)

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