FR2797308A1 - FUEL SUPPLY UNIT FOR INTERNAL COMBUSTION ENGINE - Google Patents

Abstract

The fuel supply unit of a pump (11) has a chamber (14) made in the housing (13) and a rotor housed in the chamber (14), as well as an electric motor (12) driving the pump. rotor. The rotor (29) of the electric motor (12) is formed by the rotor (16) of the feed pump (11). The electric motor is a switched reluctance motor or a so-called SR motor.

Description

The present invention relates to a unit

  fuel supply comprising a fuel pump

  tation in the form of a circulation pump or with a side channel, having a chamber produced in a housing and a pump rotor housed in the chamber as well as an electric motor driving the rotor, the rotor of the electric motor being formed.

  by the rotor of the feed pump.

  In the fuel supply units

  naked, corresponding to this type for transferring fuel from a tank to an internal combustion engine of a vehicle

  automotive (WO 95/25885), the fuel pump and the

  electric torch ensuring its drive are juxtaposed in a box. The pump rotor whose periphery is

  fitted with fins or blades, is integral with the shaft of the ro-

  tor which carries an armature or rotor winding housed in grooves and rotates in a stator occupied by segments of permanent magnets. The power supply of the armature winding is done by a switch or a current converter mounted on the rotor shaft and by

  two brushes applied to the switch by a short pressure

  diale exerted by springs. This power unit

is relatively bulky.

  According to document DE 19 752 884, there is known a fuel supply unit comprising a pump

  supply made in the form of a circulating pump

  tion or side channel, having a pump chamber made

  in the housing and a rotor housed in this chamber; the RO-

  pump tor is driven by an electric motor

  both an armature winding and permanent magnets as well as a stator and a rotor. This electric motor is a brushless motor and its rotor is formed by the rotor of the

  feed pump. In this power supply unit,

  unites the rotating parts, i.e. the rotor of the

  pump and that of the electric motor are combined. This solu-

  tion allows to realize a construction power unit

  very compact. In particular the supply unit can be very flat, that is to say with a small axial dimension. The disadvantage of this power supply unit is that of the permanent magnets fitted to the rotor, which creates difficulties in making and manufacturing relatively

  important. In addition, wear phenomena are relative-

  important in such a feed unit because of the ferromagnetic dirt particles clinging to the

rotor magnets.

  According to the technique of switching reluctance motors, switched reluctance motors known as SR are known which combine both a high maximum torque and a high efficiency for the DC motor as well as good economic and field weakening characteristics. induction motor. Such switched reluctance motors use the attraction force of an electromagnet with respect to iron. This means that the magnetic circuit

  seeks to approach the point corresponding to the refluc-

  minimum tance. We know for example such motors with

  Switched luctance having 8 stators and 6 rotor poles, corresponding to a four-phase structure. Each pole of the stator has an excitation coil. The facing poles are electrically combined so that the pair of North poles / South pole corresponds to a phase. This phase is generated by two electronic switches in a direction of the

  current using diodes to regenerate the current.

  When current is applied to a phase, it creates a cou-

  ple corresponding. The phase remains energized until the rotor and stator coils are aligned. The excitement

  sequential phase produces continuous rotation of the mo-

  tor. The object of the present invention is to develop a fuel supply unit making it possible to avoid the drawbacks described above of the known supply units. To this end, the invention relates to a power supply unit characterized in that the electric motor

  is a switched reluctance motor.

  The use according to the invention of a motor with

  switched luctance as part of the power unit

  allows to completely remove the permanent magnets ne-

  the current supply units. This results in a reduction in cost and wear. The power supply unit according to the invention is suitable for forms of

  extremely flat production of electric fuel pumps

  rant. The elimination of permanent magnetization gives mounting advantages compared to known power supply units. The use of the supply unit according to the invention eliminates the jet pump used

  usually to fill the pot of the feed pump.

  According to other advantageous features of the invention:

  * the switched reluctance motor is a four-phase motor

his;

  * the rotor of the switched reluctance motor is made of soft iron.

  It is interesting to realize the reluc-

  tance switched as a four-phase motor. The use of such an engine offers the advantage compared to the realizations

  known, of a smaller number of phases with a wavy-

  less of the torque supplied, i.e. the advantages of

  from the standpoint of silent operation.

  The invention also relates to the application of a switched reluctance motor for driving a supply pump rotor in the form of a circulation pump or

  side channel of a fuel supply unit, charac-

  that the rotor of the switched reluctance motor

  is integrated in the rotor of the feed pump.

  The present invention will be described in more detail using a preferred embodiment of a unit

  power supply shown in the accompanying drawings in the-

  which: * Figure 1 is a longitudinal or meridian section of the supply unit, the section passing through the upper half of the figure in the circulation area and through the lower half of the figure into the suction area of the power supply unit, * Figure 2 is a schematic view of the geometry of a switched reluctance motor of a power supply unit according to the invention, Figure 3 is a view of a switched reluctance motor

  turned 90 relative to the view in FIG. 2.

  The power unit shown schematically-

  ment in Figure 1 provides the fuel for a tank

  see an internal combustion engine of a motor vehicle. Usually, the supply unit is combined with a filter pot to constitute a tank equipment unit for a fuel supply tank or a fuel tank of a vehicle. The power unit

  includes a feed pump 11 in the form of a circulating pump

  culation or lateral channel and an electric motor 12 in-

  dragging the feed pump 11.

  The feed pump and the electric motor 12 are housed in a common housing 13. The construction and operation of the feed pump 11 are known.

  and are for example described in document DE 4020521 Ai.

  The housing 13 includes a pump chamber 14 delimited in

  the axial direction by two side walls 141, 142 dis-

  aunts axially from each other and extending radially and in the peripheral direction by a peripheral wall 143 connecting the two side walls. A pump rotor 16 is associated with the pump chamber 14; this rotor is integral

  in rotation of a shaft 17. The shaft 17 is housed by its ends

  respective mites in two bearings 18, 19 made in the

  two side walls 141, 142. The axis of the shaft 17 is ali-

  on the axis 161 of the rotor and on that of the pump chamber 14. The rotor 16 has a large number of blades 20,

  radial, spaced apart in the peripheral direction; unique-

  two blades are shown in the drawing. The vanes 20 are connected by an outer ring 21. Each time two

  vanes 20 delimit between them an open chamber 22 axially

  lement. It should be noted that it is also possible to provide other blade chambers located radially further away.

  the interior with respect to the chambers 22 shown.

  The rotor 16 is located opposite the side walls.

  rails 141, 142 leaving a gap and the outer ring

  laughing 21 forms with the peripheral wall 143 of the chamber

  pump 14, a radial interval. Each of the side walls

  the 141, 142 of the pump chamber 14 has a channel la-

  téral 23, 24 in the form of a groove, open towards the

  pump chamber 14, concentric with the axis 161 of the rotor and oc-

  intersecting in the peripheral direction, practically an angle of about 330 between the start of the lateral channel up to the end of it; between the end of the lateral canal and its beginning, there is an interruption. In the lower part of the section of the drawing, only the origins 231, 241 of the lateral channels 23, 24 have been shown. The end of a lateral channel is offset by approximately 330. Each lateral channel is connected by an inlet channel 25, 26, aligned radially, with a suction orifice 27 of the supply unit. The ends of the two lateral channels 23, 24 which do not appear here, are each connected by a discharge channel to a pressure nozzle of the supply unit. The electric motor is a switched reluctance motor 12 comprising a rotor 29 and a stator 28. The motor 12 is preferably a four-phase motor with 8 stator poles and 6 rotor poles as it appears for example

  in Figure 2. The stator poles each have the re-

  reference 1 and those of the rotor reference 2. Each stator pole 1 comprises an excitation coil 3; only two excitation coils have been shown. The facing poles are joined electrically to form the pair of poles

  North / South of a phase. The phase is regulated by two switches.

  electronic sensors Sl, S2; the diodes Dl, D2 shown serve for the regeneration of the current. When current is

  applied to a phase, it generates a torque. The phase remains ex-

  cited until the rotor and stator poles are aligned. A sequential excitation of the phases produces the

  continuous rotation of the switched reluctance motor 12.

  Figure 1 shows that the poles 2 are provided

  radially outside the outer ring 21 of the rotor.

  It is however also possible to have poles of ro-

  tor 2 located radially inside with respect to the outer ring. Figure 3 is an essentially rotated view of 90 relative to that of Figure 2, of the components

  of the switched reluctance motor. Figure 1 shows the common reluctance motor

  tee 12 mounted in the supply unit, with its main components, namely the stator 1, the rotor 2 and the stator windings 3. The switched reluctance motor is integrated in the rotor 16 of the pump d power 11 to have a flat construction power unit. The magnetic poles of the motor are, as described, formed by the respective electrical combination of the pairs of North / South poles in

  look at the stator poles. The poles 2 of the rotor are fixed to the outer ring 21 of the rotor 16. The poles of the stator are coaxial with the axis 121 of the rotor in the housing 13.

Claims (4)

R E V E N D I C A T I ON S   1) Fuel supply unit comprising a pump   supply (11) in the form of a circulation or heat pump   lateral, having a chamber (14) made in a housing (13) and a pump rotor housed in the chamber (14) as well as an electric motor (12) driving the rotor, the rotor (29) of the electric motor being formed by the rotor (16) of the feed pump (11), characterized in that the electric motor is a switched reluctance motor (12). 2) Power unit according to claim 1, characterized in that   the switched reluctance motor is a four-phase motor his.   3) Power unit according to one of claims   1 or 2, characterized in that the rotor (29) of the switched reluctance motor (12) is made of soft iron. 4) Application of a switched reluctance motor for driving a supply pump rotor (11) in the form of a circulation pump or with a side channel of a fuel supply unit, characterized in that the rotor (29) of the switched reluctance motor is integrated   in the rotor (16) of the feed pump (11).