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
  • H02K49/043—Dynamo-electric clutches; Dynamo-electric brakes of the asynchronous induction type of the eddy-current hysteresis type with a radial airgap

Definitions

• Electromagnetic retarder for motor vehicle.
• the invention relates to an electromagnetic retarder for reducing a rotational speed of a rotating machine, a motor vehicle and a test bench equipped with such a retarder, as well as a method of insertion. of such a retarder in a motor vehicle.
• the present invention relates to an electromagnetic retarder intended for use in a motor vehicle as an auxiliary braking device or on a test bench as an adjustable load of an engine mounted in test on this bench.
• an electromagnetic retarder such as those described in documents FR-2,440,110 and FR-2,577,357, comprises at least one stator and at least one rotor.
• the stator is crossed by a shaft and the rotor is assembled with the shaft so as to present an internal cylindrical face close to an external cylindrical face of the stator and with a thin air gap interposed between the rotor and the stator.
• the rotor and the stator are mounted coaxially and in two planes parallel to each other.
• the electromagnetic retarder model chosen it is either the rotor or the stator which comprises an even number of coils of electric wires of alternating polarity and capable of generating a magnetic field in a ferromagnetic part of the stator, when the rotor is inductive, and screw and vice versa.
• the stator comprises an inductor formed by coils of electrical wires, suitable for generating a magnetic field in a ferromagnetic part of the rotor constituting the armature.
• the metal plots of the rotor cut lines of induction of the magnetic field generated by the coils of the inductor. This results in the birth of the currents induced in the ferromagnetic part.
• an electromagnetic retarder of the invention can be transposed by analogy to other applications, for example to the application of an electromagnetic retarder in a test bench for motors or rotating machines where the braking energy used by the retarder is adjustable and constitutes a measure for the power of the engine.
• the speed of the retarder can be varied and adjusted very easily, while the inertia of a rotating mass, driven by the engine under test, is not.
• Electromagnetic retarders mainly belong to one of the following three types of retarders, namely axial type air-cooled retarders intended to be mounted on a drive shaft, Focal type (registered trademark) retarders also air-cooled and intended to be mounted at the entrance to a vehicle bridge, that is to say the transmission part driving a wheel shaft, or at the exit of a gearbox, and Hydral type retarders (registered trademark) comprising a cooling system by a circuit of a liquid.
• Hydral type retarders registered trademark
• the retarders are essentially characterized by the design of the mechanism on which they are to be mounted and by the type of connection or attachment which results therefrom.
• each of the three mounting locations for an electromagnetic retarder mentioned above in relation to the appropriate type of retarder has its own constraints, which must be taken into account for the design and improvement of the retarders.
• the assembly thus obtained must be as compact as possible, which means in particular the shortest possible in the axial direction , but must nevertheless keep sufficient dynamic freedom in the axial and transverse directions to compensate for the effects produced by the various movements of each of the two assembled parts.
• a vehicle not originally designed to be equipped with a retarder cannot always be modified to be equipped without going through fairly significant modifications to the platform or chassis of the vehicle.
• the attachment of the electromagnetic retarder to the axle or the gearbox is only safe when the gearbox or axle housing is strong enough to support the weight and in particular the dynamic forces such as the vibrations of the retarder.
• the housings of these parts are generally made of moldable material, for example cast iron or aluminum, the retarder is often fixed mainly on the chassis of the motor vehicle to unload the casing and only auxiliary, if any, on the casing itself. even.
• the electromagnetic retarder When the electromagnetic retarder is mounted on a transmission axis connecting the heat engine through a gearbox and in particular through an output axis of the latter, to drive wheels of a traction axle, care must be taken that that the electromagnetic retarder is not placed too close to parts containing synthetic material, because the retarder gives off, during moderately strong and very strong braking, a fairly significant heat which is often added to that released by the exhaust pipes .
• the heat of the retarder alone could jeopardize plastic parts, for example a fuel tank, if the retarder is not placed at a sufficient distance from such a part.
• an electromagnetic retarder can prove to be a bulky object, even if it is mounted on a drive shaft connecting the gearbox to the traction axle.
• the retarder cutting the shaft of transmission in two two additional universal joints are required to connect the retarder to these two parts of the transmission shaft.
• the universal joints also prevent the retarder from becoming mechanically hyperstatic, include the flanges necessary for their attachment to the parts they connect.
• the purpose of the present invention is to overcome the various problems set out above. More particularly, the aim of the present invention is to propose a more compact and, if possible, lighter electromagnetic retarder, capable of making the electromagnetic retarder thus easier to integrate into existing vehicle architectures and thereby avoiding development costs. new chassis or chainrings.
• the object of the invention is achieved with an electromagnetic retarder for the reduction of a rotational speed of a rotary machine, in which the retarder comprises a stator traversed by a first shaft having first and second ends axially opposite and intended to be coupled to at least a second shaft connected to a power source and a rotor linked in rotation with the first shaft so as to have an internal cylindrical face close to an external cylindrical face of the stator with a thin air gap interposed between the stator and the rotor.
• the first shaft is shaped at at least one of its two ends so as to be coupled with the shaft coming from the power source or possibly also with a shaft connected to the load, axially sliding.
• the two ends of the first shaft can be shaped so that one of the two ends receives the corresponding shaft, namely the second shaft connected to the power source or the third shaft connected to a load, by fitting and that the other of the two ends of the first shaft is received in the remaining shaft by fitting.
• the first of the two ends of the first shaft is shaped so as to receive the second shaft by fitting
• the second of the two ends of the first shaft is shaped so as to be mounted in the third shaft by fitting.
• the present invention also also relates to the following characteristics, considered in isolation or in all their technically possible combinations: -
• the axial retarders anyway and the focal retarders in most cases, are designed to be arranged in a transmission line and are for this purpose provided with a first shaft, the two ends of which are intended to be coupled to a shaft, respectively a second shaft connected to a power source and a third shaft connected to a load such as a traction axle.
• the retarder is designed to be mounted, on a rear axle of a motor vehicle, on the side opposite to the arrival of a drive shaft.
• the first retarder shaft will be intended to be coupled only to the second shaft, connected to a power source, but not to a third shaft.
• the first shaft therefore only needs to be shaped at one of its two ends for axially sliding coupling.
• FIG. 1 shows a motor vehicle with the three main locations of a retarder
• FIG. 2 schematically shows a retarder according to a first embodiment of the invention, integrated in a transmission line formed mainly by a two-part transmission shaft
• FIG. 3 shows an axial retarder installed in a transmission shaft according to a technique prior to the invention
• Figure 4 shows the retarder of Figure 2 in more detail
• FIG. 5 shows an axial retarder according to the first embodiment of the invention, but with a traditional flange on the side of the outlet of the retarder
• FIG. 6 shows a Focal retarder according to a second embodiment of the invention
• - Figure 7 shows a first variant of the retarder of Figure 6
• Figure 8 shows another variant of the retarder of Figure 6
• Figure 9 shows a retarder similar to that of Figure 7, but with an auxiliary attachment to a gearbox housing.
• Figure 1 shows schematically, in a side view, a motor vehicle in the form of a truck with indication of the three preferred locations RI, R2 and R3 of a retarder in the transmission line between an engine M and an axle carrying drive wheels RM.
• the engine M transmits a motive force to a gearbox B constituting in the context of the present invention a motive source intended to be coupled to a retarder according to the invention, through which the motive force is transmitted, the where appropriate in a reduced manner, towards the driving wheels constituting a load driven in rotation by the driving source.
• the reference RI denotes the first of the three preferred positions of a retarder according to the invention, that is to say a focal mounting of a retarder at the outlet of the gearbox B.
• the retarder is mounted directly on gearbox B, i.e. the output shaft of gearbox B is coupled to the input of the retarder and the output of the retarder is coupled to a two-part drive shaft Al, A2 interconnected.
• the mounting of an electromagnetic retarder in position R2 is an axial mounting where the retarder is connected on both sides, that is to say at the inlet and at the outlet, respectively to a drive shaft A1 or A2, the shaft Al coming from the driving source B and the tree A2 going towards the driving wheels? RM.
• the position R3 is that where a retarder according to the invention is mounted at the input of a vehicle axle, that is to say at the input of the differential of the axle carrying the drive wheels RM.
• FIG. 2 schematically represents the mounting of an electromagnetic retarder according to the invention in an arrangement corresponding to position R2 of the Figure 1.
• the retarder R is of axial type and is integrated in a transmission line according to which the driving force generated by a motor M is taken at the output of a gearbox B represented by its output shaft AS which transmits the driving force by means of an articulated flange with Cardan joint C1 and a first transmission shaft Al through the retarder R on a second transmission shaft A2 and by means of a flange with Cardan joint C2 on the bridge P.
• FIG. 3 shows the arrangement of a retarder RA dating before the invention and provided respectively on the inlet side and on the outlet side of the retarder R with flanges C3, C4 with corresponding Cardan joint.
• the driving force transmission line from the output shaft AS, passing through a flange with Cardan joint C1 is transmitted on a first transmission shaft AA1 which is slidably cooperates with a second mounted transmission shaft AA3 by the flange with Cardan joint C3 on the RA retarder.
• the RA retarder output transmits the driving force, if necessary in a reduced manner, via the flange with Cardan joint C4 on a third drive shaft AA2 mounted axially sliding on the output of the RA retarder and, by means of the flange with Cardan joint C2, on deck P of the motor vehicle.
• the main advantage of the arrangement according to the invention shown in Figure 2 and explained in more detail with reference to Figures 4 and following, compared to the arrangement prior to the invention, shown in Figure 3, consists by significantly reducing the number of parts required for a transmission line including a retarder.
• the transmission line using a retarder according to the invention comprises only two transmission shafts, Al and A2 , while the line free of the invention requires three transmission shafts, respectively AA1, AA3 and AA2.
• This advantage is obtained by integrating the sliding function of the transmission shaft into the retarder shaft. Referring to Figures 2 and 3 this means that the axially sliding connections between the shafts AA1 and AA3, on the one hand, and between the Cardan joint C4 and the shaft AA2, on the other hand, are integrated in the retarder R , as will be explained below with reference to FIGS. 4 to 9.
• An electromagnetic retarder comprises a stator 1 crossed by a first shaft 3 having a first end 31 and a second end 32.
• the first and second ends 31 , 32 are axially opposite and intended to be coupled respectively to a second shaft 4 connected to a drive source 6, for example the output shaft of a gearbox, and to a third shaft 5 connected to a load, for example via a drive shaft 7 to an axle having driving wheels.
• the retarder according to the invention also comprises a rotor 2 comprising two discs 2A and 2B in the exemplary embodiments shown in FIGS. 4 and 5, and a single disc 2 in the exemplary embodiments shown in FIGS. 6 to 9.
• the rotors 2A and 2B being identical, but only mounted in opposite position with respect to each other, they are subsequently referred to indifferently as rotor 2.
• Each rotor 2 is provided with cooling fins 23.
• the rotor 2 is assembled with the first shaft 3 so as to present an internal cylindrical face 21 to proximity of an external cylindrical face 11 of the stator 1 with a thin air gap 12 interposed between the stator 1 and the rotor 2.
• the rotor 2 is mounted on the stator 1 by means of ball bearings 24.
• the stator 1 comprises an inductor 13 formed by coils of electrical son, capable of generating a magnetic field in an annular ferromagnetic part 22 of the rotor 2, the annular ferromagnetic part 22 constituting the armature.
• the metal plots of the rotor 2 intersect lines of induction of the magnetic field generated by the coils of the inductor 13. This results in the birth of currents induced in the annular ferromagnetic part 22 of the rotor 2.
• the electromagnetic retarder according to the invention also comprises a first shaft 3 shaped at least one of its two ends, which are referenced respectively 31 and 32, so as to be coupled to the corresponding shaft, that is to say to the second shaft 4 connected to the power source 6 or to the third shaft 5 connected to the load, axially sliding.
• the first end 31 of the first shaft 3 is shaped so that the second shaft 4 is received by fitting, i.e. the grooved end of the second shaft 4 is fitted into the first end
• the third shaft 5 is fitted by its grooved end into the second hollow end 32 of the first shaft 3.
• the first shaft 3 is made entirely like a hollow shaft.
• the second and third shafts 4, 5 are mounted in the ends 31,
• the second shaft 4 is extended in the opposite direction relative to the grooved part by a first end jaw 41 constituting an integral part of a Cardan joint 42 by which a transmission shaft 6 connected to a gearbox is attached to the retarder.
• the third shaft 5 comprises at its end opposite the grooved part fitted into the second end 32 of the first shaft 3, a jaw end piece 51 intended to constitute an integral part of a Cardan joint 53 by which a shaft transmission 7 connected to drive wheels is attached to the retarder.
• the principle of the present invention rests on the fact of integrating the function of the sliding of the transmission shaft in the shaft of the retarder , that is to say in the first shaft 3.
• This makes it possible to dispense with coupling plates and thus to reduce the number of parts and the weight of the transmission lines comprising a retarder according to the invention.
• the weight reduction can be of the order of 20 kg.
• the reduction in the number of parts also provides a particular advantage when it comes to equipping vehicles initially without retarder with a retarder according to the invention: Instead of having to replace the two initial drive shafts with three drive shafts with a retarder according to the technique before the invention, only one of the two initial shafts is replaced.
• FIG. 5 shows a variant of the first embodiment of a retarder according to the invention.
• This retarder comprises a stator 1 and two rotors 2A and 2B, as well as a first shaft 3 of which only the first end 31 is shaped so as to receive a shaft, here the shaft 4, by fitting axially slidingly.
• the second shaft 4 is attached, by means of the Cardan joint 42, to the transmission shaft 6 connected to the vehicle gearbox.
• the second end 32 of the first shaft 3 is shaped so as to receive a traditional coupling in jaw end piece AM.
• the shaft 3 is mounted in the stator 1 on the side of its first end 31 by means of ball bearings 24, the first shaft 3 is mounted on the side of its second end 32 in the rotor by means of bearings 26, for example roller bearings conical intended to compensate for transverse forces with respect to the axial extent of the first shaft 3.
• the rotor 2 is fixed to the first shaft 3 in the first embodiment, represented in FIG. 4, by screws 33, the rotor 2 is fixed to the first shaft 3 according to the variant embodiment shown in FIG.
• the electromagnetic retarder of the invention is a Focal type retarder mounted axially on the output shaft 4 of a gearbox B.
• This retarder comprises, like the retarder according to the first embodiment, a stator 1 crossed by a first shaft 3 having a first end 31 and a second end 32, the two ends 31, 32 being axially opposite and coupled respectively to the second shaft 4 and to the transmission shaft 7 connected to a load, for example to drive wheels RM.
• the retarder also includes a rotor 2 assembled with the first shaft 3 so as to have an internal cylindrical face 21 near an external cylindrical face 11 of the stator 1 with a gap 12 of small thickness interposed between the stator 1 and the rotor 2
• the first shaft 3 is shaped at one of these two ends, here at the first end 31, so as to be coupled to the corresponding shaft, here the output shaft 4 of the gearbox B , axially sliding.
• the first end 31 of the first shaft 3 is shaped so as to receive the second shaft by fitting.
• the second end 32 of the first shaft 3 is shaped so as to constitute a sliding flange 8 intended to receive the transmission shaft 7.
• the sliding flange 8 comprises an integrated jaw 9 constituting an integral part of a Cardan joint 52 by which the transmission shaft 7 is attached to the retarder.
• the first shaft 3 passes through the rotor 2 and is mounted therein both integral in rotation and axially sliding. It differs in this point particularly from the axial retarders shown in Figure 4, corresponding to the first embodiment of the invention, and Focal shown in Figure 8, corresponding to the second embodiment of the invention, in which the first shaft 3 is linked in rotation with the rotor, but is not axially sliding relative to the rotor.
• the first shaft 3 fulfills both the role of the single shaft passing entirely through the retarder and having at its two opposite ends 31, 32 the input and output connections necessary for mounting it in a transmission line, and the role of third shaft 5 of the first embodiment in that it performs the function of the axially sliding coupling of a drive shaft.
• the first shaft 3 is provided with a double groove, namely an inner groove making it possible to receive, by fitting, the shaft of outlet 4 of gearbox B, and an outer groove through which the first shaft 3 is fitted into a grooved axial reservation of the rotor 2.
• the first shaft 3 penetrates inside an opening located at the axial end B2 of the gearbox nose Bl through which extends the gearbox output shaft 4 B.
• a means for guiding the shaft 3 is placed at the opening situated in the vicinity of the axial end of the nose Bl of the gearbox.
• a plain bearing such as for example a bearing.
• the retarder shown in Figures 6 to 9 is a retarder with a single rotor which further reduces the axial size.
• the retarder according to the second embodiment of the invention, shown in FIG. 6 has the advantage of reducing the axial length of the arrangement of the retarder in the vehicle.
• the rotor 2 surrounds the nose Bl of the gearbox B. More specifically, the internal cylindrical face 21 of the rotor which is opposite the external cylindrical face 11 of the stator 1 is located above the Bl nose of the gearbox. This nose Bl of the gearbox is located between one end B2 of the gearbox and the gearbox itself.
• the external cylindrical face 11 of the stator is also located above the nose of the gearbox.
• the device comprising these double sliding shafts makes it possible not to have sliding systems at the level of the transmission shaft.
• the first shaft 3 and the second shaft 4 slide in line with the rotor, which makes it possible to reduce the axial length while having a coupling over a sufficient length to ensure good transmission of the torque.
• the two shafts are arranged coaxially inside the rotor, the second shaft here being surrounded by the first shaft.
• the retarder is mounted on the gearbox B so that the rotor 2 is oriented towards the first end 31 of the shaft 3 or, in general, on the side intended to be oriented to the power source to which the retarder must be connected. Contrary to this, in the version represented in FIGS.
• the rotor 2 is oriented on the side of the end 32 of the shaft 3 or, in general on the opposite side with respect to the driving source on which the retarder must be plugged in.
• the design according to which the first shaft 3 is attached axially slidingly to two separate shafts ensures the integration of the retarder in the transmission line on the input side and on the output side of the retarder by two connections.
• the design according to which the first shaft 3 fulfills itself the function of the third shaft intended to be coupled on the input side or on the output side to a transmission shaft ensures this integration by a single connection. Consequently, any reaction coming from the side of the drive wheels is transmitted to the shaft coming from the gearbox by a single sliding link and therefore more directly than if it passed through two axially independent connections.
• the retarder according to the second embodiment comprises ball bearings 25 shaped so as to absorb the axial forces liable to act on the gearbox.
• the retarder is advantageously fixed on the chassis by means of a suspension 15, as shown in FIGS. 6, 8 and 9.
• the retarder is fixed, by means of its stator and in addition to the main fixing provided by the suspension 15, on the gearbox B by means of an auxiliary fixing 14 allowing the centering of the retarder on the gearbox.

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• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Dynamo-Electric Clutches, Dynamo-Electric Brakes (AREA)
• Braking Arrangements (AREA)

Applications Claiming Priority (2)

Publications (1)

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ID=34944499

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• 2004
  • 2004-03-24 FR FR0403045A patent/FR2869479B1/fr not_active Expired - Fee Related
• 2005
  • 2005-03-24 US US10/599,189 patent/US20080245626A1/en not_active Abandoned
  • 2005-03-24 EP EP05744628A patent/EP1754301A1/de not_active Withdrawn
  • 2005-03-24 WO PCT/FR2005/000714 patent/WO2005091479A1/fr not_active Ceased

Non-Patent Citations (1)

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