Oil tank comprising an oil level control device

Abstract

An oil tank for a turbine engine comprising a closed enclosure having the shape of an arc of circle adapted to receive oil, with the enclosure having a lower portion and an upper portion at a distance from each other, and an oil level control device in the enclosure, wherein the oil level control device comprises a first sensor positioned in the lower portion of the enclosure so as to control the oil level, and a second sensor separate from the first sensor and positioned in the upper portion of the enclosure so as to control the oil level.

Claims

1. An oil tank for a turbine engine, the oil tank comprising: a closed enclosure having the shape of an arc of a circle adapted to receive oil, with the enclosure having a lower portion and an upper portion at a distance from each other; and an oil level control device in the closed enclosure, wherein the oil level control device comprises: a first sensor positioned in the lower portion of the enclosure so as to control the oil level, wherein the first sensor includes: a first magnet; a first float attached to the first magnet; a first rail configured to guide the first float; and a first electromagnetic card that includes first contactors configured to switch between an open position and a closed position based on a position of the first magnet; and a second sensor separate from the first sensor and positioned in the upper portion of the enclosure so as to control the oil level, wherein the second sensor includes: a second magnet; a second float attached to the second magnet; a second rail configured to guide the second float; and a second electromagnetic card that includes second contactors configured to switch between an open position and a closed position based on a position of the second magnet.

2. The oil tank of claim 1, wherein the enclosure comprises a middle portion separating the lower portion from the upper portion, and wherein the first sensor is positioned so as to cover the lower portion and a part of the middle portion, and the second sensor is positioned so as to cover the upper portion and a part of the middle portion.

3. The oil tank of claim 1, wherein the enclosure comprises a sealing plug enabling at least one of the introduction and the removal of the first sensor.

4. The oil tank of claim 3, wherein the first sensor is integral with the sealing plug.

5. The oil tank of claim 1, wherein the first sensor and the second sensor are straight.

6. The oil tank of claim 1, wherein the upper portion and the lower portion each represent one-third of a total curved length of the enclosure.

7. A turbine engine comprising the oil tank of claim 1.

8. The oil tank of claim 1, wherein the first rail and the second rail are straight, and wherein the upper portion of the enclosure and the lower portion of the enclosure are curved.

9. The oil tank of claim 8, wherein the first rail and the second rail are not parallel.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will be better understood and other details, characteristics, and advantages of the invention will appear on reading the following description given by way of non-limiting example and with reference to the accompanying drawings, in which:

(2) FIG. 1 is a perspective view of a turbine engine comprising an oil tank according to the invention;

(3) FIG. 2 is a sectional view of the tank of FIG. 1 according to a first embodiment;

(4) FIG. 3 is a sectional view of the tank of FIG. 1 according to a second embodiment;

(5) FIG. 4 is detailed sectional view of a sealing plug of the oil tank of the preceding Figures;

(6) FIG. 5 is a schematic view of a sensor in an oil level control device in the tank of the preceding Figures.

DETAILED DESCRIPTION

(7) FIG. 1 shows a turbine engine 1 comprising a fan casing 2a and an inner casing 2b defining an inner space (also called a core zone) wherein the pieces of equipment of the turbine engine 1 and specifically an oil tank 3 are accommodated.

(8) The tank 3 is accommodated in a space defined outside by the inner casing 2b and inside by other elements of the turbine engine (not shown) such as the casing of a low pressure compressor, for instance. When the tank 3 is mounted in the turbine engine 1, the radius of curvature thereof is thus large and the access thereto is limited.

(9) The tank 3 which is shown in section in FIGS. 2 and 3 comprises: a closed enclosure 4 having the shape of an arc of circle, defined by walls 5 wherein oil is received, with the enclosure having a lower portion 6 and an upper portion 7 at a distance from each other, and separated by a middle portion 8, and an oil level control device 9 in the enclosure 4.

(10) The lower portion 6 and the upper portion 7 each advantageously represent one third of the total curved length of the enclosure 4.

(11) As shown in FIGS. 2 and 3, the control device 9 comprises a first sensor 10 positioned in the lower portion 6 so as to control the oil level, and a second sensor 11 separate from the first sensor 10 and positioned in the upper portion 7 of the enclosure 4 so as to control the oil level.

(12) The sensors 10, 11 are preferably straight sensors, which are simpler to manufacture than curved sensors, specifically as regards production accuracy.

(13) According to a first embodiment, shown in FIG. 2, both sensors 10, 11 respectively have a length greater than the height of the lower portion 6 and of the upper portion 7 of the tank 3. In this embodiment, the first sensor 10 is positioned so as to cover the lower portion 6 and a part of the middle portion 8, and the second sensor 11 is positioned so as to cover the upper portion 7 and a part of the middle portion 8.

(14) Both sensors 10, 11 advantageously have a length substantially equal to half the total curved length of the enclosure 4. The oil level can thus be checked at any point of the tank 3. It should however be noted that the FIGS. 2 and 3 are schematic and do not show the lower, upper and middle portions 6, 7, 8 at a real scale.

(15) According to a second embodiment, shown in FIG. 3, both sensors 10, 11 respectively have a length smaller than the height of the lower portion 6 and of the upper portion 7 of the tank 3. In this embodiment, the first sensor 10 then makes it possible to monitor the oil level in the lower portion 6 of the tank only and the second sensor 11 makes it possible to control the oil level in the upper portion 7 of the tank 3 only.

(16) Both sensors 10, 11 advantageously have a length slightly smaller than the height of the lower and upper 6, 7 portions, i.e. slightly smaller than one third of the total curved length of the enclosure 4.

(17) The first sensor 10 can be attached in the tank either permanently, in which case it will not be possible to change the first sensor 10 in case of failure (the whole tank 3 will then have to be replaced), or removably.

(18) If the attachment is removable, the tank comprises a sealing plug 12 on one of its walls. The first sensor 10 can then be inserted into or removed from the enclosure 4 through an opening 13 in the wall 5 which will be plugged by the sealing plug 12 once positioned on the wall 5.

(19) According to a first alternative solution, the first sensor 10 may be held in the enclosure 4 by stops (not shown).

(20) According to a second alternative solution, the sensor may be integral with the sealing plug 12, as shown in FIG. 4.

(21) When the first sensor 10 is removably attached, the tank has to be drained (i.e. some oil must be removed therefrom) until a level under the sealing plug 12 is reached, so that, when opening the sealing plug 12, oil will not flow out of the tank through the opening 13.

(22) The second sensor 11 can be knowingly attached in the tank 3, i.e. through an access door (not shown), with the second sensor 11 thus being possibly removable.

(23) FIG. 5 schematically shows a specific type of sensor which corresponds to the sensors 10, 11 used for checking the oil level in the tank 3. Such sensor comprises a float 14 which follows the oil level and is guided by rails 15 and comprises a magnetic element. An electromagnetic card 16 carrying contactors 17 which interact with the magnetic element of the float 14 is positioned opposite the float 14.

(24) When the level in the tank changes, the float 14 moves along the electromagnetic card 16 and the magnetic element acts with the contactors 17. The contactors 17 then switch from an open position to a closed position, or reversely, and an electric signal circulates in the electromagnetic card 16 and is transmitted to an acquisition unit 18, distant from the tank 3, which transforms such electric signal into information legible by a pilot or a flight engineer.

(25) The electric signal is transmitted by an electrical lead 19 associated with the first sensor 10 and an electrical lead 20 associated with the second sensor 11. Both electrical leads 19, 20 can advantageously be joined in a sheath 21.

(26) Thus, when oil is in excess in the tank 3, the float 14 of the second sensor 11 is in a high position and the electric signal sent to the acquisition unit 18 is transformed into an alarm signal for the pilot or the flight engineer so that an intervention can be carried out on the tank 3 and the excess of oil can be removed.

(27) Thus, when oil is lacking in the tank 3, the float 14 of the second sensor 10 is in a low position and the electric signal sent to the acquisition unit 18 is transformed into an alarm signal for the pilot or the flight engineer so that an intervention can be carried out on the tank 3 and oil can be added into the tank 3.

(28) When the oil level in the tank 3 is correct, the float 14 of the first sensor 10 is in a high position and the float 14 of the second sensor 11 is in an intermediate position or in a low position (in all cases, in a position away from the high position thereof).

(29) The tank 3 which has just been described has some advantages, such as: a gain in the mass of the tank 3, in that two small size sensors can be used instead of only one large size sensor; easy maintenance, in that the access to the first sensor 10 is available through the opening 13 and the sealing plug 12, or still a precise control of the quantity of oil in the tank 3 in that knowing the quantity of oil in the middle portion 8 of the tank 3 is not always useful since the lack (in the lower portion 6) and the excess (in the upper portion 7) of oil only are critical.