Aircraft turbine arrangement including a lubrication pump driven by two helical gears

Abstract

A pump (12) which may be a gear pump driven by a rotating body of an aircraft turbine, such as a blower shaft, the pump always rotating in the same direction by means of a transmission comprising a helical double gear (19) formed by a toothed wheel (20) on the rotating body side and meshing with two pinions (21, 22) connected to a pump drive shaft (23) via freewheels (26, 27) having the same drive direction, while the pinions (21, 22) have opposite directions of rotation.

Description

Technical Field

[0001] The subject of the invention is an aircraft turbine engine arrangement comprising a lubrication pump driven by two helical gears. Background Art

[0002] The pump is used to inject oil into the equipment to be lubricated (e.g. a reducer), which is located, for example, between two rotating bodies carrying blades of a turbine engine. One particularly envisaged application (not exclusive) is such an arrangement in a turbine engine with an upstream fan, in which a gear reducer connects the fan shaft to the shaft of a low-pressure spool, and the pump is a pump of an auxiliary lubrication circuit driven by one of these shafts.

[0003] The equipment considered here must be lubricated in all conditions of machine operation to avoid damage, but certain specific conditions may prevent the correct operation of the pump responsible for lubrication. This situation may occur if the rotating body driving the pump rotates in the direction opposite to the normal direction, which then drives the oil into the supply tank, while the gear reducer remains driven. This may occur in conditions where the rotating body of the engine rotates freely ("turns like a windmill"), for example, on the ground under the influence of the wind, the fan may rotate in the direction opposite to the normal direction.

[0004] The subject of the present invention is an improvement of this arrangement which makes it possible to maintain lubrication of the device even in the event of a reversal of the direction of rotation of the rotating body driving the pump.

[0005] More specifically, the arrangement constituting the invention makes it possible to propose a simple and compact arrangement, in particular avoiding the necessity to repeat pumps or other components of the arrangement, so that the arrangement is suitable for supplying the equipment whatever the direction of rotation of the rotating body. The arrangement also comprises a single pump driven by a single transmission having only a mechanism for absorbing the reversals of the driving direction, so that the movement imposed on the pump is always in the same direction. Another advantage is that the arrangement can be installed with great freedom in the usually very small free space of a turbine engine. Summary of the invention

[0006] In a general form, the invention therefore relates to an arrangement of an aircraft turbine engine, the arrangement comprising a body rotating about an axis and carrying blades, equipment to be lubricated and a circuit for lubricating the equipment, and a drive transmission connecting the rotating body of the turbine engine to the pump, characterized in that the transmission comprises a first rotating shaft connected to the pump, two pinions having an axis of rotation parallel to the first shaft and connected to the first shaft by means of two freewheels with the same sliding rotation direction, the toothed wheel meshing with each of the pinions forming two helical gears and driven by a second rotating shaft connected to the rotating body via the transmission.

[0007] The only repetitive part of the arrangement is therefore the pinion provided with a freewheel, all the rest of the transmission being effective in both directions of rotation of the rotating body.

[0008] The second rotation axis can form any angle with the axis of the rotating body. The angle is usually a right angle or close to a right angle, but it can also be any angle, including zero degrees.

[0009] A configuration to which the invention can be particularly applied is characterized in that the device is a rotary reducer placed between the fan and the low-pressure rotor of the turbine engine, and in that the rotary body driving the pump is the fan body.

[0010] According to certain optional and advantageous features of the invention:

[0011] - the pinions are all carried by the first shaft and are therefore coaxial with the first shaft via the freewheel;

[0012] - the device is a rotary reducer, and the lubrication circuit further comprises an oil supply tank and a lubrication pipe, the lubrication pipe extending from the oil tank to the straight device and passing through the pump;

[0013] -The angles of helical gears are all right angles;

[0014] - The pump is adjacent to a rolling bearing that serves as a support for the shaft, the bearing carrying teeth that are connected to the gear that drives the pump;

[0015] - the pinion is conical and the toothed wheel also has a conical set of teeth;

[0016] - the rotating body carries a set of teeth connected to the second shaft via a single gear;

[0017] - An arrangement comprising a cover surrounding the pinion and said toothed wheel, the cover being provided with two bearings supporting the first shaft and a bearing supporting the second shaft.

[0018] Another general aspect of the invention relates to the possibility of an arrangement provided by a transmission comprising a second rotating shaft, which drives a toothed wheel and advantageously extends to the set of teeth belonging to the rotating drive body. This second shaft can be perpendicular to the axis of the rotating body, which makes it possible to offset the pump arrangement by any distance in the radial direction of the turbine engine; the second shaft can also be inclined in the direction of the axis of the rotating body, which also makes it possible to offset the arrangement by any axial distance in the turbine engine.

[0019] Thus, the arrangement can be installed in the free space as close as possible to the equipment to be lubricated. As has been seen, one advantageous possibility can be to place the arrangement adjacent to the rolling bearing, which itself is adjacent to the equipment; another advantageous possibility is to place the arrangement adjacent to the oil tank to reduce or eliminate dry running of the pump; it is even possible to place the pump inside the oil tank.

[0020] Another aspect of the invention is a turbine engine comprising a device according to the above. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The various aspects, features and advantages of the present invention will now be described in more detail by means of the following drawings, which show preferred embodiments of the present invention and which are given for illustrative purposes only:

[0022] Figure 1 is a general view of a turbine engine showing possible locations of the present invention;

[0023] Figure 2 Generally, embodiments of the present invention are shown;

[0024] Figure 3 is a detailed view of the end of the arrangement and the end of the pump;

[0025] Figure 4 is a cross section through the portion;

[0026] Figure 5 is a second embodiment of the present invention;

[0027] Figure 6 is the third embodiment of the present invention;

[0028] Figure 7 This is the fourth embodiment of the present invention. DETAILED DESCRIPTION

[0029] Reference Figure 1 .

[0030] The turbine engine includes a stator 2 and a rotor 3, which are also annular, in an annular nacelle 1. The rotor rotates in a central recess of the stator 2. The rotor 3 includes a concentric low-pressure rotor 4 and a high-pressure rotor 5. The axis around which the rotor 3 and all rotating bodies constituting the rotor 3 (including the fan 6) are rotated is marked as XX. The low-pressure rotor 4 extends through the fan 6 upstream of the turbine engine and the airflow passing through the turbine engine. The turbine engine includes a compressor, a combustion chamber and a turbine, which are conventional elements downstream of the fan 6 and are not repeated. The illustrated embodiment includes a primary flow channel 7 and a secondary flow channel 8, the primary flow channel extending around the rotor 3 and surrounded by the stator 2, the secondary flow channel surrounding the stator 2 and surrounded by the nacelle 1, and the fan 6 extending in front of the primary flow channel 7 and in front of the secondary flow channel 8; however, this construction is not necessary for the implementation of the present invention.

[0031] The reducer 9, which connects the rotation of the low-pressure rotor 4 to the rotation of the fan 6, must be permanently lubricated once it is no longer stationary. Therefore, there is a lubrication circuit, such as Figure 2 In summary, the lubrication circuit comprises an oil supply tank 10 and a lubrication pipe 11 originating from the tank 10, which extends up to the reducer 9 and comprises a pump 12 through which the lubrication pipe passes, responsible for circulating the oil to the reducer 9. The tank 10 is advantageously placed below the reducer 9 (in the normal orientation of the turbine engine), in the casing 40 of the turbine engine fixed to the stator 17. This arrangement enables the oil to be guided from the reducer 9 to the tank 10 by gravity and then returned to the reducer 9 by the device according to the invention once the fan 6 is no longer at rest. Continuous lubrication is thereby ensured. The pump 12 is a gear pump. The gear pump is driven by an external gear 13 through a group of teeth 14, which rests on a fan shaft 15, which is driven by the fan 6 and is connected to the reducer 9. Preferably, the external gear 13 is the only gear between the fan shaft 15 and the second shaft 28 described below. The low-pressure rotor 4 is also connected to the reducer 9. The pump 12 may pass through the cylindrical surface 17 of the stator 2 adjacent to the rolling bearing 16 for supporting the fan shaft 15, but this is not required.

[0032] The transmission 18 for driving the pump 12 from the gear 14 also includes a double gear 19, which is connected to the pump 12 by the gear 14. Figure 3 Give a description.

[0033] This double gear 19 comprises a toothed wheel 20 meshing by two opposite sets of teeth with two pinions 21 and 22 coaxial along an axis called first axis 23 for driving the pump 12 and, more precisely, for driving a guide pinion 24 located inside a housing 25 of the pump 12. The pinions 21 and 22 are identical and supported by the first axis 23 respectively via freewheels 26 and 27, the sliding rotation directions of which are identical. The toothed wheel 20 is connected to the external gear 13 via a second axis 28 driving the toothed wheels. The first axis 23 is perpendicular to the second axis 28 and the pinions 21 and 22 and the toothed wheel 20 have sets of teeth of a conical shape and form right-angled gears 29 and 30. The gears 29 and 30 may be replaced by other right-angled gears having sets of teeth of other forms. The assembly is supported by a cover 31 which houses the gear 20 and the pinions 21 and 22 in a central space 32 of the assembly, and supports the first shaft 23 by bearings 33 and 34 and the second shaft 28 by bearings 35. The cover 31 and the housing 25 are attached to the stator of the turbine engine by means not shown.

[0034] Since the sliding rotation directions of the freewheels 26 and 27 are the same, it can be seen that when the second shaft 28 and the toothed wheel 20 rotate in one direction, the first shaft 23 is driven in one direction through the gear 29, and when the second shaft 28 and the toothed wheel 20 rotate in the opposite direction, the first shaft is driven in the same direction through the other gear 30. Therefore, the direction of movement of the guide pinion 24 and the other pinion 36 inside the pump 12 is always the same, and the oil is always driven in the same direction through the pipe 11, which emerges inside the housing 25, in front of the gear 37 formed by these two pinions 24 and 36. It can thus be seen that the device is very simple and compact and that it involves a very small number of parts that are repeated, making it possible to ensure the persistence of the oil flowing in the correct direction regardless of the direction of rotation of the rotating body driving the pump 12, here the fan shaft 15. The choice of the conical set of teeth for the toothed wheel 20 and the pinions 21 and 22 increases the robustness and compactness of the device.

[0035] Figure 5Another possible embodiment of the invention is shown. In the previous embodiment, the second shaft 28 was a shaft extending in the radial direction of the turbine engine and of a shorter length, so as to place the arrangement mainly including the pump 12 and the double gear 19 close to the rolling bearing 16. This is not necessarily advantageous, and the shaft 28 can be replaced by a shaft 38 with an inclined direction and thus with an inclination in the direction of the axis XX, which allows the pump 12 to be offset in the axial direction as well, with the advantage that the lubrication pipe connecting the oil tank 10 to the reducer 9 will be shortened. In the embodiment shown here, on the one hand, the pump 12 is located at the middle radius of the oil tank 10, and on the other hand, the axial position of the rolling bearing 16 and the reducer 9 is offset towards the rear of the turbine engine with respect to the previous embodiment, close to the axial position of the oil tank 10.

[0036] Another structure to consider is Figure 6 , in which the short second shaft 28 of the first embodiment and the medium-length second shaft 38 of the second embodiment are replaced by a long second shaft 41, so as to place the arrangement consisting of the pump 12 and the double gear 19 adjacent to the tank 10. The shaft 41 may be perpendicular to the axis XX or not. In the variant embodiment shown here, it is even possible to place the pump 12 inside the tank, which may be optionally modified according to the contour 42 to be able to accommodate the pump 12. This arrangement makes it possible to reduce or even omit the portion of the lubrication pipe 11 upstream of the pump 12 and therefore to have a period of time during which the pump 12 risks running dry if this portion of the lubrication pipe has been emptied.

[0037] More generally, the length and inclination of the shaft transmitting the motion to the double gear 19 can thus be adjusted in order to place the double gear and the pump 12 in the most appropriate position. Then, by exploiting the motion of the pump 12, it becomes possible and advantageous to modify other surrounding arrangements, for example in relation to the fan 6.

[0038] Some other possibilities of construction will now be explained. Firstly, the first shaft 23 driving the pump 12 does not necessarily have to be driven directly by one or the other of the freewheels 26 and 27, nor do the axes of the freewheels 26 and 27 have to be aligned with each other or with the axis of the guide pinion 24: a transmission (e.g. a reducer) can be added to the embodiments described so far to adjust the rotation speed of the guide pinion 24 according to the rotation speed of one or the other of the freewheels 26 and 27, or to provide greater freedom of placement of the components of the arrangement. Of course, the placement of the first shaft 23 common to the guide pinion 24 and to each of the freewheels 26 and 27 has the advantage of simplicity.

[0039] We will now deal with another possible variant embodiment of the invention, according to which Figure 7, the right-angled bevel gears 29 and 30 are replaced by other bevel gears 129 and 130, the values ​​of α and β of which are different. The components modified relative to the previous embodiment have the same reference numerals here but with 100 added. α and β are also the angles between the axis of rotation of the second shaft 128 and the axis of rotation of the pinions 121 and 122; here, α>β and α+β=180°. In this structure, the pinions (now 121 and 122) have different diameters and numbers of teeth, the inclination of the toothed wheel 120 driving the pinions relative to the first shaft 23 remains unchanged, the second shaft 128 is tilted accordingly, and the cover 131 can be modified according to these other differences in the structure. The rest of the device can remain unchanged. The advantage of this variant embodiment is that it is possible to drive the guide pinion 24 at different speeds according to the speed of the second shaft 128 and according to the direction of rotation of the fan shaft 15, which corresponds to possibly different situations or lubrication requirements.

Claims

1. An assembly of an aircraft turbine engine, comprising a rotating body, a device to be lubricated (9), a circuit for lubricating the device, and a drive transmission, the rotating body rotating about an axis and carrying blades, the circuit for lubricating the device comprising a pump (12), the drive transmission connecting the rotating body of the turbine engine to the pump, characterized in that The drive transmission device comprises a first rotating shaft (23), two pinions (121, 122) and a toothed wheel (120), wherein the first rotating shaft is connected to the pump, the two pinions have a rotation axis and are connected to the first rotating shaft by two free wheels (26, 27) with the same sliding rotation direction, the toothed wheel meshes with each of the two pinions to form two helical gear sets and is driven by a second rotating shaft (128), which is connected to the rotating body through a transmission device, There is a first angle (α) between the rotation axis of the second rotating shaft and the rotation axis of one of the two pinions, and there is a second angle (β) between the rotation axis of the second rotating shaft and the rotation axis of the other of the two pinions, the first angle (α) is greater than the second angle (β), and the sum of the first angle (α) and the second angle (β) is equal to 180°.

2. The assembly according to claim 1, characterized in that The device (9) is a rotary speed reducer, and the rotating body is a fan body (6) of the turbine engine, and the speed reducer is arranged between the fan body and the low-pressure rotor (4) of the turbine engine.

3. The assembly according to claim 1 or 2, characterized in that The circuit also comprises an oil tank (10) and a lubrication pipe (11), which extends from the oil tank (10) to the device (9) and passes through the pump (12).

4. The assembly according to claim 1 or 2, characterized in that The pump (12) is adjacent to a rolling bearing (16) which serves as a support for the rotating body.

5. The assembly according to claim 4, characterized in that The rotating body carries a set of teeth connected to the second rotating shaft by a single gear.

6. The assembly according to claim 1 or 2, characterized in that The turbine engine assembly comprises a cover (131) surrounding the pinion and the toothed wheel and provided with two bearings supporting the first rotating shaft and a bearing supporting the second rotating shaft.

7. The assembly according to claim 1 or 2, characterized in that The pinions are both carried by the first rotating shaft and are coaxial with the first rotating shaft by means of the freewheel.

8. The assembly according to claim 1 or 2, characterized in that The second rotation axis is inclined along the axis direction of the rotating body.

9. The assembly according to claim 3, characterized in that The pump (12) is adjacent to the oil tank (10) or is inside the oil tank.

10. A turbine engine, characterized in that: The turbine engine comprises an assembly according to any one of claims 1 to 9.

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