FR2538861A1 - SUBMERSIBLE PUMP DEVICE, PARTICULARLY FOR SUPPLYING A FUEL BURNER - Google Patents

Abstract

1. An arrangement for supplying a receiving member with liquid originating from a supply chamber comprising : - a blind body (19) prevented from rotation and mounted so as to be able to slide on a rotatable driving shaft (16) ; - a cam mechanism (16A, 19A) disposed between the body and the shaft to produce, in co-operation with a spring acting on the body, an alternating movement of low amplitude of the body on the shaft, in response to the rotation of the shaft ; - the blind body (19) and the shaft defining between them a pumping cavity (24), the volume of which varies as a result of the action of the cam mechanism when the shaft rotates, and which communicates with a port (23) provided on the shaft, said port (23), when the shaft rotates, being alternately positioned in relation with a suction opening (21), and a delivery opening (22), made in the blind body, characterised in that it comprises a supply chamber (18), connected with the suction opening (21), and in which the blind body (19) is housed, while a seal (25) is mounted between the rotatable shaft and a fixed wall (26) of the supply chamber, and in that the delivery opening (22) is connected to a manifold (31, 32) ending outside the supply chamber.

Description

The present invention relates to a device

  supply of liquid to a receiving organ,

  nant a submerged pump and intended in particular but not exclusively to supply a burner with liquid fuel.

  Patent FR 2 448 054 describes a pump, in particular

  ment for liquid fuel comprising a blind body immobilized in rotation and mounted so as to be able to slide back and forth on a rotary shaft, for example directly on the shaft of an engine A cam mechanism disposed between the body and the shaft , for example constituted by the machined end of the shaft, produces the alternating rectilinear movement of the body along the axis of the shaft and therefore the cyclic variation of the volume of a pumping chamber defined by the end of the tree and interior

of one-eyed body.

  This extremely simple pump is well suited to the low liquid flow rates to which it is directed

  users for reasons of economy.

  However, it has the drawback of requiring between the drive shaft and the open end of the blind body a dynamic type seal subject not only to the stresses resulting from the rotation of the shaft, but also to the alternating stresses produced by the sliding of the body back and forth on the shaft We understand that the fatigue of the joint

  is significant and leads to a significant risk of leakage.

  In addition, such a pump displaces very low fuel flow rates, unlike conventional pumps with oversized flow and recycling; the supply of air bubbles to the pump is therefore

  more annoying and can cause the burner to go out.

  -2- The object of the invention is in particular to remedy the cited drawbacks of pumps of the type described and to create a liquid supply device which is

  reliable, inexpensive and compact.

  It relates to a device serving to supply liquid to a receiving member from a supply chamber and comprising: a blind body immobilized in rotation and mounted so as to be able to slide on a rotary motor shaft, a cam mechanism disposed between the body and the shaft to produce in cooperation with a spring acting on the body a movement back and forth thereof on the shaft in response to the rotation of the shaft, the blind body and the shaft defining therebetween a pumping cavity whose volume varies under the effect

  of the cam mechanism when the shaft rotates and which

  munique with a light provided on the tree and put itself in alternating relation, when the tree turns,

  with a suction port and a discharge port-

  spared in the blind body.

  The device according to the invention comprises a supply chamber, connected to the suction orifice and in which is housed the blind body, while a seal is mounted between the rotary shaft and a fixed wall of the feed chamber, and that

  the discharge orifice is connected to an end pipe

  weaving outside of it.

  The life of the seal is thus improved by the fact that it is only subjected to the low load of the liquid in the supply chamber and that it does not have to bear stresses due to the alternating sliding of the body. on the rotating shaft In addition, the immersion of the vibrating body in the chamber allows wide manufacturing tolerances, particularly for the body since the leakage of the liquid between the body and the shaft is no longer a

  hinders and contributes to the lubrication of the body bearing-

  tree. Preferably, the supply chamber is mounted on the motor shaft in the form of a supply sub-assembly including the blind body and a degassing device. The latter can advantageously comprise a rigid or flexible tube connecting the suction orifice of the blind body to the interior space of the chamber, the tube having a liquid drawing orifice and

  a higher level an opening allowing the elimination

  progressive air bubbles reaching the chamber.

  This degassing device is another

  important aspect of the present invention, and may furthermore

  their to be used in a supply chamber which would not internally contain the

  pumping, we would use a pump of a different kind.

  In the particular case of supplying fuel to a burner, the chamber can be formed in one piece with a flange or with the motor or fan casing. It can of course be engaged with the gasket on the drive shaft to be removably attached to the flange or to the casing In both cases, it is desirable to provide access to

inside the room.

  The pump body can be immobilized in rotation by the discharge hose connecting the body discharge orifice To an outlet connection of the

  chamber and / or by a suction hose connecting the ori-

  fice of suction of the body to the interior space of the

  bedroom; the suction hose can of course

  replace the degassing tube envisaged previously The design of the supply device is based on the

sort simplified.

  -4- Other features and advantages of

  the invention will appear on examination of the description

  detailed which will follow and attached drawings, on

which: -

  Figure-1 schematically shows an axial section of a burner equipped with the supply device according to the invention; Figure 2 shows an enlarged schematic section of the device of Figure 1;

  FIG. 3 represents the device in cross section

  versale according to the plan III-III of figure 2, and figure 4 represents in an enlarged view the elements

of the pump in Figures 2 and 3.

  We see in Figure 1 a burner 10 compre-

  providing a device 11 for supplying liquid fuel, a fan 12 of known type with an outer casing 13, a combustion head 14 and organs

regulation and control 15.

  An electric motor of axis X-X of which only the shaft 16 and its ball bearing 13 A has been indicated allows

  to activate the fan 12 and a pump-17 of the device

feeder 11.

  As best shown in Figures 2 and 3, the device 11 has a fuel chamber 18 and a blind body 19 slidably mounted on the end of the shaft 16 The body 19 can be immobilized in rotation by cooperation of a tenon and a complementary mortise provided on the body and on a fixed part of the chamber 18; it is however preferably prevented from rotating by connection hoses and

  by a return spring which will be described later.

  The body 19 is movable on the shaft 16 in an alternating translation of small amplitude by means of a cam mechanism constituted either by a cam flange formed on the shaft, or by a cam machined at the end 5- of the shaft and cooperating with an eccentric stopper provided inside the body Such arrangements have been

  described in patent FR 2 448 054-.

  However in the preferred embodiment-

  tiel of the present invention, there is provided (Figure 4) a stop machined at the end of the shaft 16 A, which cooperates with an inclined cam surface 19 A provided internally at the

  bottom of the blind body 19, during its molding in synthetic material.

  In this way, the flow rate of the pump can be very simply adjusted by exchange of the blind body 19,

the tree 16 remains the same.

  When the drive shaft 16 rotates, the cam mechanism produces the comings and goings of the blind body 19 on the shaft in cooperation with a weak return spring 20 interposed between the body and a fixed wall 18 A of the

feed chamber.

  The blind body 19 has (FIG. 3) a suction orifice 21 and a discharge orifice 22

  substantially opposite; these orifices are alternately

  in connection during rotation of the shaft with a lumen 23 of the shaft itself open on a pumping cavity 24 of cyclically variable volume,

  formed between the body and the tree.

  According to the invention, the blind body 19 is housed

  in the supply chamber 18 and its suction orifice

  ration 21 communicates with the volume of liquid contained in the chamber under normal pumping conditions while a seal (O-ring 25 and / or lip seal 25 A) is arranged between the rotary shaft 16 and a wall fixed 26 of the supply chamber It will be easily understood that the seal 25 only supports the stresses due to the rotation of the shaft, as well as the low pressure due to the reduced height of the liquid in the chamber In addition, the body 19 can now be manufactured with a wide tolerance since the leaks of liquid return to the chamber while lubricating the bearing; finally, the spring 20 can be lightened as a result of the reduction in the weight of the body stripped of the seal, the stop 17 A (FIG. 4 *) of the spring therefore also being able to be lightened. A flexible tube 27 located in the chamber 18 is

  connected to the suction nozzle 21 It has an opening

  re 29 at its free end A calibrated orifice of drawing

  28 is provided in the tube 27 or better in the suction nozzle.

  piration 21 The normal level of liquid in the chamber is designated by h 1 The opening 29 is located higher than the calibrated orifice 28, and higher than the level h 1 The chamber 18 has an inlet connection 30, fitted with a 30 A filter. An at least partly flexible tube 31 is connected on the one hand to the discharge orifice 22 of the blind body, on the other hand to an outlet connection 32 of the

room 18.

  It should be noted that the hoses 27, 31 help to immobilize the blind body 19 in rotation while allowing its alternating sliding of small amplitude on the shaft. The hoses are for example in abutment against the internal wall of the supply chamber Note that the rupture of one of the

  hoses do not have the effect of external liquid leakage.

  The described degassing supply device operates as follows

  In established regime and when there is no arr-

  air flow at the inlet connection 30, the positive displacement pump 17 ensures the same liquid flow rate at the connection 30, at the calibrated orifice of draw-off 28, at the suction orifice 21; the orifice 28 is calibrated so that the level of the

  liquid in the chamber stabilizes at height h 1-

  ensuring a sufficient load to pass the flow.

Z 538861

  -7- When a certain amount of air suddenly arrives at the connection 30, the level of the liquid drops to a level h 2 indicated in dashes in FIG. 2 this level being insufficient to ensure the flow d at the orifice 28 The flow at the suction port 21 being unchanged, the volumetric compensation is effected by suction of air through the opening, 29 and the tube 27 The air

  is therefore associated with the liquid in the form of micro-

  bubbles sucked into port 21 at each pumping cycle.

  The volume between the calibrated orifice 28 and the lumen 23 is less than the displacement of the pump and thus ensures perfect regularity s The excess air in the supply chamber

  18 is then gradually canceled by sending micro-

  air bubbles with the fuel, towards the burner, and

  this without causing its untimely extinction.

  As previously indicated, this degassing device can be used with a pump 17 different from that

  described above, submerged or not.

  Furthermore, it can be seen that the presence of the seal 25 in a fixed wall 26 of the chamber

  18 ensures constant wetting of the pump 17.

  The blind body 19 constitutes (where appropriate with the flexi-

  ble 27 and the hose 31) an interchangeable component allowing a change of flow rate In fact, to change the flow rate it will suffice to replace a component provided with a body 15 with cavity 24 and with calibrated orifice 28 by a component with cavity, surface of inclined cam and calibrated orifice dimensioned differently - This can be done easily after opening the 18 A cover of the

room 18.

  It goes without saying that changes can be made

  cations to the embodiment described without necessarily

depart from the scope of the invention.

2538861.

-8-

Claims (7)

  1 device for supplying liquid to a receiving member from a supply chamber comprising a blind body immobilized in rotation and mounted so as to be able to slide on a rotary motor shaft, a cam mechanism disposed between the body and the shaft to produce in cooperation with a spring acting on the body an alternating movement of low amplitude of the body on the shaft, in response to the rotation of the shaft, the blind body and the shaft defining between them a cavity pumping volume varying under the effect   of the cam mechanism when the shaft rotates and which   munique with a light provided on the tree and put itself in alternating relation, when the tree turns,   with a suction port and a discharge port-   spared in the one-eyed body,   characterized by the fact that it comprises a feed chamber   mentation (18), connected to the suction orifice (21), and in which is housed the blind body (19), while a seal (25) is mounted between the rotary shaft and a wall fixed (26) of the supply chamber, and that the discharge orifice (22) is connected to a tube   (31, 32) ending outside the feed chamber tation.   2 Feeding device as claimed   cation 1, -characterized by the fact that-the feed chamber   mentation (18) comprises an inter-venting device   placed between an inlet fitting (30) of the chamber and the suction opening (21).   3 Feeding device as claimed   cation 2, characterized in that the degassing device comprises a tube (27) connecting the orifice 9-   suction (21) inside the feed chamber   tation, the tube (27) having at a predetermined level an orifice (28) for drawing liquid and at a level higher than that of the orifice (28) and that of the liquid in the chamber, an opening (29) allowing eliminating it   nation of air bubbles reaching the supply chamber tation (18).   4 Feeding device according to one of   Claims 1 to 3, characterized in that the   supply chamber (18) is mounted on the motor shaft (16) as a supply sub-assembly including the blind body (19).   Feeding device as claimed   cation 4, characterized in that the feed chamber   mentation (18) includes the seal (25).   6 Feeding device according to one of   Claims 1 to 5, characterized in that the   blind body (19) is immobilized in rotation by at least a connection hose (31) -   7 Supply device as claimed   cation 6, characterized in that at least one flexible   connection (27) is in abutment against the inner wall   of the supply chamber (18).   8 Feeding device according to one of   Claims 1 to 7, characterized in that the   tube (27) connected to the supply orifice (21) is flexible. 9 Liquid fuel burner comprising the   feeding device defined by one of the claims 1 to 8.