BE1027701B1 - Motor-pump - Google Patents

Abstract

Motor-pump (5) comprising a positive displacement pump (1), the principle of which comprises axially sliding vanes (22) in a rotor (20). These pallets (22) follow a guide (11), which can for example be tracks on flanges (12, 13). Two successive vanes (22) form a cavity whose volume varies periodically during the rotation of the rotor (20) thanks to the sliding of the vanes (22), cyclically inducing a suction of the fluid in the pump (1) then a discharge. .

Description

4- Motor-pump Technical field

The present invention relates to a pump motor incorporating a positive displacement pump, preferably for use in the field of aeronautics.

Prior

In various applications, it is necessary to use pumps, for example to lubricate the various components of a turbomachine of an aircraft. For this purpose, there are so-called gerotor pumps as described for example in EP1396639A1 and EPO736691B1.

Another type of pump consists of the family of vane pumps. These pumps comprise a rotor provided with blades (or vanes) which can slide radially, causing variations in the volumes of the cavities defined in particular by said vanes, which produces suction and discharge phases.

Known vane pumps have the drawback of being bulky.

Summary of the invention

One of the aims of the invention is to provide a particularly compact positive displacement pump. To this end, the invention provides a motor-pump for aircraft turbomachine equipment, and comprising a positive displacement pump comprising: e a stator comprising a guide: e a rotor located in the stator, capable of rotating about an axis , comprising a plurality of notches passing through it axially, and delimiting in the stator an upper zone and a lower zone: ee a plurality of vanes for dividing said upper and lower zones into a plurality of cavities, said vanes being able to: co-rotate around said axis,

2.co slide in the notches with a movement having at least one axial component, and o Slide along the guide, the guide radially surrounding said axis and having a shape such that it is able to impose said movement having at least one component axial to said pallets during their rotation about the axis; the ponnpe motor further comprising coils mechanically coupled to the stator, and magnets attached to the rotor; the motor-pump being arranged so that the coils are able to induce a rotation of the rotor by a magnetic coupling with the magnets.

Unlike a radial vane pump, the vanes of the pump according to the invention move with a movement having a component parallel to the axis of rotation of the rotor. The movement of said pallets is carried out mechanically using the guide, the height of which, that is to say its axial extent, varies circumferentially along a rotational path of the pallets. This height variation imposes the back and forth movement of the pallet through the notch and causes the volume of the cavities to vary during their rotation. The sliding along the guide is a movement having a circumferential component created by the rotation of the rotor which drives the vanes.

[0007] The coils form electromagnets. A current in these can induce a magnetic field which will induce a force on the magnets attached to the rotor, and which creates a rotation of the rotor and actuates the pump. This arrangement of the pump as a motor-pump allows a particularly low mass and bulk. In addition, several pumping functions can be performed using a single pump motor and the pulsation level is particularly low.

In a known vane pump, the movement of the vanes is only radial, and is therefore particularly influenced by the centrifugal force. In the pump according to the invention, as the movement of the vanes has a

-3. axial component, the centrifugal force has less influence and the radial load is particularly small. Thus, the magnets and coils suffer little when using the pump according to the invention. It is therefore particularly advantageous to integrate them into a motor-pump as described in this document.

If only one pumping function is performed, the pump motor is axially balanced. If several pumping functions are performed simultaneously, the axial load is particularly low. A "pumping function" can here be understood as a "pumping action" between an inlet and an outlet of a pump cavity.

The pump is arranged to allow the assembly formed by the rotor and the vanes to be sealed during the movement of the vanes. The cavities are delimited in particular by two neighboring vanes, the stator and the rotor, and are preferably sealed with respect to one another. The rotor delimiting a lower zone and an upper zone (which are distinct and preferably fluidly disconnected) in the pump, there are therefore twice as many cavities as there are vanes. Thus, two vanes in fact delimit two cavities facing each other: an upper cavity in the upper zone of the pump and a lower cavity in the lower zone of the pump. As the paddles move to the upper area, the volume of the upper cavity increases while the volume of the lower cavity decreases. The guide is configured so that the volume of each cavity oscillates during the rotation of the rotor.

The configuration of the pump is such that the cavities can be fluidly connected with an inlet or an outlet of the pump, in this case the cavities are said to be open. When the cavities are not fluidly connected to an inlet or an outlet, they are said to be closed. The variation in the height of the guide is such that, when a cavity is open and connected to an inlet of the pump, its volume increases, thus generating a phenomenon of suction of the fluid in the pump. Conversely, when a cavity is open

„4- and connected to an outlet of the pump, its volume decreases, thus generating a phenomenon of discharge of the fluid contained in the cavity towards the outside of the pump. Between an inlet and an outlet, the cavity is closed and moves the fluid in the pump. In other words, a fluid is sucked into a cavity of the pump, moved in the pump by rotation of the rotor and then discharged outside the pump. The depression and overpressure respectively caused by the increase and decrease in the volume of the cavities are such as to move a fluid from a low pressure area to a high pressure area. The oscillating nature of the volume of the cavities makes it possible to repeat this operation indefinitely over time. The volume of a closed cavity is maximum immediately after filling and minimum immediately after emptying. This is to avoid any countercurrent flow of inputs and outputs. The pump inlets and outlets can be axial or radial. The shape of the guide influences the rate of change in volume of the cavities. It is therefore possible to modify the shape of the guide in order to control this variation in volume and therefore the flow rate of the pump.

The configuration of the invention as described makes it possible to have a number of depression / compression cycles per revolution greater than two In fact, a pump can include 2K vanes, ie 4K cavities and therefore up to N inputs and N outputs (N21, K2N}, corresponding to an alternation of open and closed cavities. In order to prevent the same cavity from being simultaneously connected to an inlet and an outlet, it is preferable that there is a buffer cavity between a inlet and outlet, which means four inlets and four outlets for eight vanes. Generally speaking, the more vanes, the more functions the pump can perform. So a single axial vane pump can replace a plurality. radial vane pumps which reduce the weight and size of the pumping system.

Advantageously, increasing the depression / compression cycle per revolution of the rotor makes it possible to increase the suction / discharge frequency and reduces the effects of pulsation.

-5-

The inlets and outlets of the pump are preferably axial. it is nevertheless possible that the inlets and outlets are radial while restoring within the scope of the invention.

In the context of this document, it should be understood that when elements are described and / or shown as in contact, or in "mechanical" contact, there may be a clearance between these elements.

[0016] In the context of this document, two "mechanically coupled" elements can for example form a single integral part, or be inserts attached to one another.

In the context of this document, the adjectives "interior" and "exterior" must be understood with respect to the axis of rotation of the rotor.

In a first embodiment of the invention, the movement of the pallets in the notches is a translation in a direction parallel to the axis. In a second embodiment of the invention, said movement having at least one axial component comprises an inclination of the pallets with respect to the axis.

In one embodiment of the invention, the stator comprises an upper flange and a lower flange, parallel to the rotor and arranged on either side of the rotor. The flanges are preferably made of a material that is not very conductive and not very magnetic. A flange is a flat mechanical part, ict, preferably circular.

In one embodiment of the invention, the guide comprises a first track mechanically coupled to the upper flange and a second track mechanically coupled to the lower flange, each track radially surrounding, and at least partially, said axis el having a shape adequate to impose said movement having at least one axial component auxdiles pallets on at least part of their rotation about the axis.

The two tracks are two distinct elements arranged so as to cooperate via the pallets, Indeed, the two tracks are separated by a distance equal to the axial extension of the pallets, so each pallet is

-6- permanently in contact with the first track by its upper side and with the second track by its lower side.

The tracks are directed towards the rotor. Each track describes on its flange a preferably circular periphery, along the perimeter of a circle. Along their peripheries, the height of each of the tracks varies continuously and preferably in a correlation with the height of the other track. For example, as the height of one track increases, the height of the other track decreases similarly and vice versa, allowing the paddles to slide into the notches. The tracks can take turns to force the movement of the paddles: for example, the first track can force the movement downwards and the second track can force the movement upwards.

In one embodiment of the invention, each of the upper and lower flanges comprises at least one inlet basin and at least one outlet basin of the pump.

In one embodiment of the invention, the rotor comprises, along its outer perimeter, an upper axial extension and a lower axial extension arranged to block the vanes radially outwards. Preferably, the magnets are mechanically coupled to said upper and lower axial extensions.

In one embodiment of the invention, the pump motor comprises a first inlet, a first outlet and a cooling circuit fluidly connected to the first inlet or to the first outlet, in thermal contact with the coils and arranged so as to cause a fluid to rotate around at least part of the coils. This makes it possible to cool the coils thanks to the fluid passing through the pump.

In one embodiment of the invention, the motor-pump comprises a first inlet and a first outlet for a first pumping function, a second inlet and a second outlet for a second pumping function, and a fluid connection between the first exit and the

-7- second entry. Thus, each of the two pumping functions forms a pumping stage.

In one embodiment of the invention, the pump motor further comprises a sealing jacket between the coils and the cavities.

The invention further provides an assembly comprising a first and a second motor-pump according to any one of its embodiments.

In one embodiment of the invention, each of the motor-pumps comprises an inlet and an outlet, the inlet of the second motor-pump being fluidly connected to the outlet of the first motor-pump.

In one embodiment of the invention, each motor-pump comprises a shaft, the shafts of the first and of the second motor-pumps being axially aligned and arranged so that one shaft can drive the other shaft, or for be trained by the same training element. This drive element may for example be a central shaft meshed with the shafts of each of the motor-pumps.

The invention further provides an aircraft turbomachine and an aircraft comprising a pump motor according to any of its embodiments.

In one embodiment of the invention, the turbomachine comprises a lubrication unit in which the pump motor comprises a first inlet and a first outlet arranged for a pumping function of supplying the turbomachine with oil, and a second inlet and a second outlet arranged for an oil recovery pumping function. It is also possible that the engine has four functions: one function of supplying oil to the turbomachine, and three functions of collecting oil or a mixture of air and oil.

The invention proposes a use of a pump motor in which a current flowing through the coils induces a magnetic field acting on the magnets such that the rotor rotates around the axis, driving the vanes in a

The rotational path during which the paddles slide along the guide, the guide pushing the paddle in a movement having an axial component. In this use, the rotor turns around the axis, causing the pallets in a rotational course during which the pallets slide along the guide, the guide pushing the pallet in a movement having an axial composition and varying the volume of the cavities. .

A reverse use of the pump motor would be to use it as a generator, by passing a fluid through the pump which causes the rotor to turn and generates an electric current in the coils.

Brief description of the figures

In order to illustrate the invention and the detailed description which follows, reference is made to the figures where: - Ja Figure 1 shows part of a positive displacement pump, which can be included in a pump motor according to a first embodiment realization of the invention; - Figure 2a is a side view of part of a positive displacement pump, which can be included in a pump motor according to a second embodiment of the invention: - Ja Figure 2b is a vertical sectional view of a part of a positive displacement pump, which can be included in a motor-pump according to a second embodiment of the invention; - Ja Figure 3 is a sectional view of a pump motor according to one embodiment of the invention: - Figure A is a top view of part of a pump motor according to an embodiment of invention; - Ja figure Sa is a view of part of a motor-pump according to an embodiment of the invention: - Figure 5b is a view of a motor-pump according to an embodiment of the invention;

-9- - Ja figure Ga is a view of part of a motor-pump according to an embodiment of the invention); - Ja Figure 6b is a view of part of a pump motor according to one embodiment of the invention: - Ja Figure 7 is a diagram illustrating a possible path for a fluid circulating in a pump motor according to one embodiment. embodiment of the invention, and FIG. 8 is a diagram illustrating a possible path for a fluid circulating in two motor-pumps according to the invention fluidly connected together.

Detailed description of particular embodiments of the invention

The present invention is described with particular embodiments and references to figures but the invention is not limited by them. The drawings or figures described are only schematic and are not limiting.

In the context of this document, the terms "first" and "second" serve only to differentiate the different elements and do not imply order between these elements.

In the figures, identical or similar elements may bear the same references.

Figure 1 shows part of a positive displacement pump 1, which can be included in a pump motor according to a first embodiment of the invention. Figures 2a and 2b show part of a positive displacement pump 1, which can be included in a pump motor according to a second embodiment of the invention. This document first describes some of the elements common to these two embodiments of the invention. The characteristics described with reference to FIGS. 3 to 8 are compatible with the two embodiments presented here.

The positive displacement pump 1 comprises a stator 10, a rotor 20 and a plurality of vanes 22. Preferably, the stator 10 comprises an upper flange 12 and a lower flange 13. The rotor 20 is located, axially, between

-10- the flanges 12, 13. The rotor 20 can be symmetrical with respect to a plane 101.

A sealed envelope of the pump 1 comprises in particular the flanges 12,

13. A fluid, for example water, air, fuel or oil, can enter the pump through an inlet 2a, 2b and exit through an outlet 3a, 3b. These can for example take the form of basins 2a, 2b, 3a, 3b axially crossing the flanges 12,13.

The rotor 20 is designed to rotate around an axis of rotation A when using the pump 1. Preferably, the rotor 20 comprises an essentially flat and circular part capable of rotating without unbalance around its axis of rotation At. The rotor 20 is located between the flanges 12,13 of the stator, separating the pump into two zones: an upper zone 51 located between the upper flange 12 and the rotor 20 and a lower zone 52 located between the rotor 20 and the lower flange 13 .

Preferably, the rotor 20 is in one piece with a shaft 50 parallel to and passing through the axis of rotation λ. The shaft 50 passes through the flanges 12,13 of the stator 10. The rotor 10 comprises notches which pass through it axially. Preferably, each notch is identical and extends radially. In the example shown in FIG. 1, the notches are rectangular.

The vanes 22 are provided to insert and slide in the notches of the rotor 20 so that the rotor and the vanes form a tight barrier between the lower 52 and upper 51 zones.

10044! The stator 10 comprises a guide 11. Preferably, the guide 11 comprises a first track 61 fixed to the upper flange 12 and a second track 62 fixed to the lower flange 13. The tracks of the flanges 12, 13 are directed towards the rotor 20, c ' that is to say downwards for the first track 61, and upwards for the second track 62. These tracks can be formed by a variation in height of the flange 12, 13 (which was manufactured as such) or correspond to an attached mechanical part mechanically coupled to the flange 12, 13. De

Preferably, each pallet 22 is in contact by its upper side 23 with the first track 61 and by its lower side 24 with the second track 62.

Preferably, at any time of the rotation, at least one of the tracks 61, 62 pushes the paddles 22, which causes the paddles 22 to slide in the notches 21. Preferably, when the height of the upper flange 12 varies, the height of the lower flange 13 varies in the opposite manner. For example, the two flanges 12,13 are identical and face each other, one being rotated by 90 ° with respect to the other in a rotation along the axis A. Ideally, the two flanges 12,13 are complementary, that is, they complement each other if they are nested within each other. Preferably, the height of the flanges 12, 13, measured axially, varies periodically as a function of the circumferential angle 105. The total circumference, that is to say the 360 ° for the circumferential angle 105, corresponds to a whole number of period (s) of the height of the flanges. The guide 11 allows that, during the rotation of the rotor 20, the volume of each cavity 4 oscillates: when this volume increases, the cavity 4 can suck a fluid, and when this volume decreases, the cavity 4 can push a fluid.

A cavity 4 is delimited in particular by two successive vanes 22, the rotor 20, one of the flanges 12,13.

Each zone 51, 52 is connected to the outside of the pump by at least one inlet 2a, 2b and one outlet Za, 3b. If a zone 51, 52 is connected to the outside of the pump by several inputs 2a, 2b and outputs 3a, 3b, each input 2 is located between two outputs 3. Thus, each cavity 4 is in contact! fluidic alternately, during rotation, with an inlet 2 then an outlet 3, so as to be alternately filled and more emptied.

Magnets 81, preferably permanent magnets, are mechanically coupled to the rotor 20. They are described in more detail later in this document,

[0049] The pallets 22 preferably have six sides. The two lateral sides are preferably flat.

-12-

[9050] In the first embodiment of the invention, shown in Figure 1, the notches 20 have inner and outer ends, in contact respectively with inner sides 26 and outer 25 of the pallets, parallel to the axis λ. The inner 26 and outer 25 sides of the pallets are also parallel to the axis λ. The sliding of the pallets 22 in the notches 21 is a translation of the pallets 22 in a direction parallel to the axis A. The sliding of the pallets is then only axial. Preferably, the height of the track then varies only circumferentially and the track is, radially, perpendicular to the axis.

In the second embodiment of the invention, shown in Figures 2a and 2b, the movement of the pallets 22 in the notches comprises a tilting movement of the pallets 22 relative to the axis λ. Preferably, to obtain this variation in the inclination of the pallets 22, the height of the part of the guide 11 which is in contact with a pallet Z2 varies radially in addition to varying circumferentially, during the rotation of this pallet 22. Preferably, the pallets 22 are each symmetrical with respect to a plane of symmetry 102. Two opposite pallets 22 may have the same plane of symmetry, as shown in FIG. zb. The planes of symmetry 102 of the pallets 22 preferably intersect at a point of intersection 53 situated on the axis A.

When the pallet 22, the angle 100 between its plane of symmetry 102 and Paxe λ varies. Preferably, the upper side 23 and the lower side 24 move away from each other away from the axis λ. For example, the pallets 22 can have a trapezoidal shape. The interior side 26 is preferably convex, in order to incline on the shaft 50.

Figures 3 to 6 are different views of a motor-pump 5 according to one embodiment of the invention. In addition to the pump 1, the motor-compe 5 comprises coils 82 fixed to the stalor 10 and magnets 81 mechanically cut to the rotor 20. Preferably, the motor-pump 5 comprises a sealing jacket 83 between the coils 82 and the cavities 4. .

-13-

In operation, the current in the coils 82 creates a magnetic field which acts on the magnets 81 so as to rotate the rotor 20. The guide 11 allows that, during the rotation of the rotor 20, the volume of each cavity 4 oscillates: when this volume increases, the cavity 4 can suck a fluid via an inlet 2a, 2b, and when this volume decreases, the cavity 4 can discharge the fluid via an outlet 3a, 3b.

The invention proposes several variants as to the mechanical coupling between the magnets 81 and the rotor 20. Certain characteristics of these variants are compatible. In a first variant, the magnets 81 are on the outer perimeter of the rotor 20, in continuity with the plane of the rotor 20 (see FIGS. 1 and za). In a second preferred variant, the rotor 20 comprises, along its outer perimeter, an upper axial extension 210 and an inner axial extension 220 arranged to block the vanes 22 radially outwards, and the magnets 81 are mechanically coupled to said axial extensions 210, 220 (see FIG. 3 in particular). In a third variant, the magnets 81 are integrated in the rotor 20, for example the rotor 20 can be in a magnetic material or the magnets 81 can be placed in the rotor 20 during its manufacture. It is also possible, while remaining within the scope of the invention, for the magnets 81 to extend radially, in the rotor 20, between the notches 21.

[9055] As illustrated in Figures 7 and 8, if the pump motor 201 comprises at least two inlets 2a, 2b, and at least two outlets 3a, 3b, the first outlet 3a can be fluidly connected to the second inlet 2b. For example, in one embodiment of the invention, the path of a fluid is as follows. |! arrives in the pump motor 201 via an inlet duct 91 and the first inlet Za. It is pumped by undergoing a first pumping function 92 and passes through the first outlet 3a. It then passes through a fluidic connection 93 and then through the second inlet 2b. It is pumped by undergoing a second pumping function 94 and passes through the first outlet 3b and then through an outlet pipe 95. This makes it possible to obtain two pumping stages. If pump 1

-14- includes more functions, it is possible to have more pumping stages. For example, there could be two stages corresponding to the upper zone 51 and two stages corresponding to the lower zone 52. The fluidic connection 93 can be inside or outside the casing of the pump 1.

In the example of Figure 7, the fluidic connection 93 between the first outlet 3a and the second inlet 2b comprises a cooling circuit 89 located at least partially around the coils 82. This allows heat transfer from the coils 82 towards the fluid passing through the fluidic connection 93. Such a cooling circuit 89 could be present upstream of the first inlet 2a, and / or downstream of the second outlet 3b.

In the example of Figure B, the outlet duct 95 forms the inlet duct 91 of a second motor-pump 202. The two motor-pumps 201, 202 form a pump assembly.

The invention further provides a pumping assembly in which the shafts 50 of the pumps 1 are axially aligned. They are preferably arranged so that one of the shafts 50 can drive the other in rotation, or that a drive element drives the two shafts 50. For example, the pumps 1 can each have a hollow shaft 50, and of preferably in one piece with the rotor 20. The pumping assembly preferably comprises a central shaft forming a drive element and having an axial tongue engaged in an axial groove of the hollow shafts 50, so as to be able to drive them simultaneously by meshing.

In other words, the invention relates to a pump motor 5 comprising a positive displacement pump 1, the principle of which comprises axially sliding vanes 22 in a rotor 20. These vanes 22 follow a guide 11, which can for example be tracks on flanges 12, 13. Two successive vanes 22 form a cavity whose volume varies periodically during the rotation of the rotor 20 thanks to the sliding of the vanes 22, cyclically inducing a suction of the fluid in the pump 1 then a discharge

-15-

The present invention has been described in relation to specific embodiments, which have a purely illustrative value and should not be considered as limiting. In general, the present invention is not limited to the examples illustrated and / or described above. The use of the verbs "to understand", "to include", "to include", or any other variant, as well as their conjugations, can in no way exclude the presence of elements other than those mentioned. The use of the indefinite article "un>," a ", or the definite article" the "," the "or" | », To introduce an element does not exclude the presence of a plurality of these elements. Reference numbers in the claims do not limit their scope.

Claims (15)

-16- Claims 1. Motor-pump (5) for aircraft turbomachine equipment, and comprising a positive displacement pump (1) comprising: e a stator (10) comprising a guide (11); e a rotor (20) located in the stator (10), capable of rotating about an axis (A), comprising a plurality of notches passing through it axially, and delimiting in the stator (10) an upper zone (51) and a lower zone (52); "A plurality of paddles (22) for dividing said upper (51) and lower (52) zones into a plurality of cavities (4), said paddles (22) being able to: co-rotate about said axis (A), co-slide in the notches with a movement having at least one axial component, and sliding along the guide (11), the guide (11) radially surrounding said axis (A), being in contact with the pallets (22), and having a shape such that it is able to impose the movement having at least one axial component auxdiles pallets (22) during their rotation around the axis (A); the pump motor (5) further comprising coils (82) mechanically coupled to the stator (10), and magnets (81) mechanically coupled to the rotor (20); the motor-pump (5) being arranged so that the coils (82) are able to induce a rotation of the rotor (20) by a magnetic coupling with the magnets (813. 2. Moleurpompe according to claim 1, arranged so that said movement having at least one axial component comprises an inclination of the vanes (22) with respect to the axis (A). -17- 3. Motor-pump according to any one of the preceding claims, characterized in that the stator (10) comprises an upper flange (12) and a lower flange (13), parallel to the rotor (20) and arranged on both sides. the other of the rotor (10). 4. Motor-pump according to the preceding claim, characterized in that the guide (11) comprises a first track (61) mechanically coupled to the upper flange (12) and a second track (62) mechanically coupled to the lower flange {13}, each track (61, 62) radially surrounding, and at least partially, said axis (A) and having an adequate shape to impose said movement having at least one axial component to the pallets (22) on at least part of their rotation around axis (A). 5. Motor-compe according to any one of the preceding claims, characterized in that the rotor (20) comprises, along its outer perimeter, an upper axial extension (210) and a lower axial extension (220) arranged to block the pallets. (22) radially outward. 6. Motor-pump according to the preceding claim, characterized in that the magnets {81} are mechanically coupled to said upper (210) and lower (220) axial extensions. 7. Moleurpompe according to any one of the preceding claims, comprising a first inlet (2a), a first outlet (3a) and a cooling circuit (89) fluidly connected to the first inlet (2a) or to the first outlet (33), in thermal contact with the coils (82) and arranged to rotate a fluid around at least a portion of the coils (82). -18- 8. Compe motor according to any one of the preceding claims, comprising a first inlet (2a) and a first outlet (3a) for a first pumping function (52), a second inlet (2b) and a second outlet (3b) for a second pumping function (84), and a fluid connection (93) between the first outlet (Ga) and the second inlet (2b). 9. Assembly comprising a first (201) and a second (202) motor-pumps according to any one of the preceding claims, 10. Assembly according to claim 9, characterized in that each of the motor-pumps (201, 202) comprises an inlet (2a, 2b) and an outlet (3a, 3b), the inlet (2a, 2b) of the second motor -pump (202) being fluidly connected (95) to the outlet (3a, 3b) of the first motor-pump (201). 11. Assembly according to claim 9 or 10, characterized in that each motor-pump (201, 202) comprises a shaft (50), the shafts (50) of the first (201) and of the second (202) motor-pumps being axially aligned and arranged so that one shaft (50) can drive the other shaft (50), or to be driven by the same drive element. 12. Aircraft turbomachine or turbomachine lubrication unit comprising a pump motor (5) according to any one of claims 1 to 8 or an assembly according to any one of claims 9 to 11. 13. Aircraft turbomachine comprising a lubrication unit comprising a moleurpompe (5) according to any one of -19- preceding claims 1 to 8 or an assembly according to any one of claims 3 to 11, characterized in that the pump motor (5) comprises a first inlet (2a) and a first outlet (3a) arranged for a function of pumping for supplying the turbomachine with oil, and a second inlet (2b) and a second outlet (3b} arranged for an oil recovery pumping function. 14. Aircraft comprising a turbomachine according to the preceding claim. 15. Use of a pump motor (5) according to any one of claims 1 to 8, wherein a current flowing in the coils (82) induces a magnetic field acting on the magnets (81) such that the rotor (20) rotates around. of the axis (À), causing the paddles (22) in a rotational path during which the paddles (22) slide along the guide (11), the guide (11) pushing the paddle (22) in a movement having an axial component.