Aircraft braking device equipped with a sensor for measuring the braking torque of said device.

Abstract

An aircraft wheel braking device comprising at least one stack of rotor and stator discs, an actuator housing, an actuator mounted in the actuator housing to exert a pressing force on the disc stack, the actuator housing comprising a landing gear connection portion and an actuator receiving portion and being provided with a first deformation sensor. The first deformation sensor comprises a test body having a first end mechanically and removably fixed to the connection portion and a second end mechanically and removably fixed to the receiving portion, and a transducer fixed to the test body for measuring a deformation of the test body. Lander and aircraft comprising such a device. [Figure from the summary: Fig. 4]

Description

Title of the invention: Aircraft braking device equipped with a sensor for measuring the braking torque of said device.

[0001] The present invention relates to the field of braking and in particular to the measurement of braking torque.

[0002] BACKGROUND OF THE INVENTION

[0003] An aircraft wheel braking device includes at least one stack of rotor and stator discs, an actuator housing linked in rotation to the landing gear, and actuators mounted in the actuator housing to exert a pressing force on the stack of discs and thus generate a braking torque on the wheel.

[0004] It is useful for controlling the braking system to have a measurement of the braking torque. It is known to measure the braking torque by attaching a transducer, such as a strain gauge, directly to one of the brake components undergoing the deformations due to the torque.

[0005] The strain gauges are bonded to said components. However, the type of adhesive used, as well as the thickness and uniformity of the adhesive layer, will influence the transmission of stresses between the component subjected to the braking torque and the strain gauge. It is therefore understandable that the bonding method and the operator's habits affect the subsequent measurement of deformations. Furthermore, the behavior of the adhesive generally depends on temperature conditions. These effects primarily lead to errors in hysteresis, repeatability, and temperature drift, thus reducing the measurement accuracy of the strain gauge.

[0006] SUBJECT OF THE INVENTION

[0007] The invention aims in particular at the integration of a sensor enabling the precise measurement of braking torque in an aircraft wheel. Summary of the invention

[0008] To this end, the invention provides a braking device for an aircraft wheel, comprising at least one stack of rotor and stator discs, an actuator housing, an actuator mounted in the actuator housing to exert a pressing force on the stack of discs, the actuator housing comprising a connection portion to the landing gear and an actuator receiving portion and being provided with a first deformation sensor. The first deformation sensor comprises a test body having a first end mechanically and removably fixed to the connection portion and a second end mechanically and removably fixed to the receiving portion, and a transducer fixed to the test body to measure a deformation of the test body.

[0009] Thus, the transducer is not fixed directly to the actuator housing but to a test body which is itself fixed to the actuator housing. The fixing is removable, allowing for quick and easy sensor replacement. The fixing is mechanical (as opposed to a chemical fixing such as bonding), ensuring more reliable and efficient stress transmission, particularly due to its lower sensitivity to temperature conditions. This type of simple fixing also allows for better repeatability. The result is improved measurement accuracy, stable operation, and easier maintenance.

[0010] According to optional features, used individually or in whole or in combination: - the test body is held under tension on the casing; - The housing includes two radially protruding tabs with free ends between which the body of the test extends; - the free end of each of the legs is pierced with a hole to receive one end of the test body, the holes being coaxial; - at least one end of the test body is provided with an axial stop bearing against one of the legs and at least one end of the test body includes a thread, cooperating with a pre-stressing element, allowing tensioning of the test body; - the free end of at least one of the legs is pierced with a hole perpendicular to the test body, the test body being connected to said at least one of the legs by a pin received in the perpendicular hole, said at least one of the legs and the test body being arranged to cooperate with a tool for tensioning the test body before the introduction of the pin into the perpendicular hole; - the test body of the first sensor takes the form of a bar comprising end sections having an axis of symmetry, on either side of a central section having a thinner cross-section accommodating the transducer; - the test body of the first sensor has at least one geometric element enabling the test body to be prevented from rotating around the axis of symmetry of the end sections, by collaborating with the housing; - an electrical connector is positioned at one end of the first sensor and a hole extends from said end of the test body to the transducer to receive at least one electrical wire connecting said electrical connector to said transducer; - the test body is a profiled bar having a U-shaped cross-section, possessing a central web and two fins; - a second sensor positioned on another part of the brake housing so as to measure a different deformation than that measured by the first sensor.

[0011] The invention also relates to a landing gear and an aircraft comprising at least one wheel braked by means of such a device.

[0012] Other features and advantages of the invention will become apparent from the following description of particular, non-limiting embodiments of the invention. Brief description of the drawings

[0013] Reference will be made to the attached drawings, among which:

[0014] [Fig-1] is an elevational view of an aircraft equipped with braked wheels fitted with a braking device according to the invention;

[0015] [Fig.2] is a schematic half-view in cross-section of one of the braked wheels of this plane.

[0016] [Fig.3] is a general view of the actuator housing of the device according to the invention;

[0017] [Fig.4] is a partial front view of a braking device according to a first method of implementation;

[0018] [Fig.5] is a partial perspective view of the actuator housing of this device with an exploded view of the sensor;

[0019] [Fig.6] is a partial perspective view of a braking device according to a variant of the first embodiment;

[0020] [Fig.7] is a partial front view of a braking device according to a second method of implementing the invention;

[0021] [Fig.8] is a partial front view of a braking device according to a variant of the second embodiment of the invention;

[0022] [Fig.9] is a partial perspective view, with an exploded view of the sensor, of a device braking according to a third embodiment of the invention;

[0023] [Fig. 10] is a partial perspective view of a braking device according to a fourth embodiment of the invention;

[0024] [Fig. 11] is a partial perspective view of a braking device according to a fifth embodiment of the invention;

[0025] [Fig. 12] is a partial cross-sectional view of a braking device according to another variant of the second embodiment;

[0026] [Fig. 13] is a general front view of a braking device according to a sixth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0027] With reference to figures 1, 2 and 3, the invention is described in application to an aircraft 100 comprising main landing gear having legs 3 having one end articulated to a structure of the aircraft 100 and opposite a free end provided with an axle 103 on which wheels 101 are pivotally mounted.

[0028] Each wheel 101 comprises a rim 6 carrying a tire 7, a hub 5 extending coaxially to the rim 6, defining with it an annular space 6.1, and a disc 6.2 connecting the hub 5 to the rim 6.

[0029] Each of the wheels 101 is equipped with a braking device generally designated as 11.

[0030] Each braking device 11 comprises a stack of discs 8 housed in the annular space. The stack of discs 8 comprises alternating rotor discs 8.1 rotationally connected to the rim 6 and stator discs 8.2 carried by a torsion tube 9 and rotationally connected to the latter. The two end discs of the stack of discs 8 are stator discs 8.2. The torsion tube 9, coaxial with the axle 103, extends around the hub 5 and has a first end fixed to a flange 10 of the axle 103 and an opposite end free, forming a stop for the stack of discs 8.

[0031] The braking device further includes an actuator-carrying housing 2 having receiving parts 3.2 in each of which is fixed an actuator 13 arranged to exert, via a support plate 12 in contact with the adjacent end disc, a pressing force on the stack of discs 8. The housing 2 has a crown shape having an inner circumference pivotally engaged on the torsion tube 9 (or the flange 10 of the axle 103) and further includes a linking part 3.1 which receives a lug 3.3 extending projecting from the leg 3 to oppose a rotation of the housing 2 around the axle 103 during braking.

[0032] The braking method is conventional: the actuators are controlled to deploy and exert, via the support plate 12, a pressing force on the stack of discs 8: the stator discs 8.2 are then pressed against the rotor discs 8.1 and by friction generate a braking torque on the rotor discs 8.1.

[0033] It is therefore understood that, during braking, the rotating rim 6 exerts a reaction torque on the stack of discs 8 corresponding to the braking torque. The stack of discs 8 transmits this reaction torque to the actuators 13 bearing against the stack of discs 8 via the support plate 12. This results, at the level of the housing 2, in a slight deformation between the connecting part 3.1, which is directly rotationally linked to the leg 3, and the receiving parts 3.2, adjacent to the connecting part 3.1, which are rotationally linked to the actuators that transmit the reaction torque to them.

[0034] The housing 2 is equipped with a deformation sensor 1 which is fixed on an external surface of the housing 2 and which includes a test body 1.1 and a transducer 1.2 for measuring a deformation of the housing 2 between the connecting part 3.1 and one of the receiving parts 3.2 adjacent to the connecting part 3.1. The transducer 1.2 is positioned on the test body 1.1 in contact with an area of ​​the test body 1.1 subjected to the deformations likely to be undergone by said test body 1.1.

[0035] The housing 2 has on its outer surface two tabs 2.2 extending radially from said outer surface of the housing 2. One of the tabs 2.2 is positioned at the level of the connecting element 3.1 between the housing 2 and the leg 3 of the lander, and the other tab 2.2 is positioned at the level of the receiving part 3.2. The free ends of the tabs 2.2 are drilled to attach to each of the tabs 2.2 one end of the test body 1.1.

[0036] With reference to figures 2 and 3, and according to the first embodiment, the test body 1.1 has the form of a bar comprising two end sections 1.1.1, and 1.1.2, cylindrical with circular cross-section, on either side of a central section 1.1.3 on which the transducer 1.2 is fixed.

[0037] The central section 1.1.3 of the test specimen 1.1 is thinner than the end sections 1.1.1 and 1.1.2, and is shaped like a plate with two parallel and opposite flat principal faces. The central section 1.1.3 is positioned on the central axis of the end sections 1.1.1 and 1.1.2. The transducer 1.2 is fixed by any means to one of the principal faces of this central section 1.1.3. It should be noted that bonding is feasible since the bonding is carried out at the factory under controlled conditions ensuring maximum repeatability. The geometry of the central section 1.1.3 concentrates the strain stresses, allowing the transducer 1.2 to measure the strain as precisely as possible.

[0038] The free ends of the two legs 2.2 each have a transverse hole. These two holes are coaxial and each receive one of the end sections 1.1.1, 1.1.2 of the proof body 1.1.

[0039] The end section 1.1.1 of the sensor body 1.1 is positioned in the hole of the leg 2.2.1. The end section 1.1.1 includes a shoulder forming an axial stop bearing against said leg 2.2.1.

[0040] The end section 1.1.2 of the test body 1.1 of the sensor 1 is positioned in the hole of the leg 1.1.2 and is arranged to cooperate with a prestressing element in order to put the test body 1.1 under tension.

[0041] To this end, the end section 1.1.2 includes a threaded axial housing and a screw 1.1.10 having a head bearing against the second leg 2.2.2.

[0042] In order to prevent unintentional rotation of the test body 1.1 in the holes of the legs 2.2 around its axis of symmetry, a geometric element is provided allowing the test body 1.1 to be locked in rotation, by cooperating with the geometry of one of the legs 2.2. A key 1.1.13 extends radially outward from the end section 1.1.1 and is received in a groove formed along the hole in the leg 1.1.1 (the hole in question and the groove have a keyhole shape) as best seen in [Fig.3].

[0043] An electrical connector is also provided at the end section 1.1.1 of the test body 1.1. This connector is suitable for connecting the transducer 1.2 to an electronic processing unit (not shown) arranged to process the signal from the transducer, which is representative of the braking torque. This connector 1.1.4 is housed in a recess in the end section 1.1.1 and is connected to the transducer 1.2 by an electrical conductor extending in a conduit that opens on one side into the connector recess and on the other side near the central section 1.1.3.

[0044] In the variant of the first embodiment shown in [Fig.4], the holes through the free ends of the legs 2.2 are opened longitudinally opposite the housing 2 so as to facilitate the introduction of the end sections 1.1.1, 1.1.2 into said holes.

[0045] Furthermore, it is provided here that the central section 1.1.3 of the test body 1.1 is wider than the end sections 1.1.1 and 1.1.2 to allow the use of a transducer which would be wider.

[0046] According to the second embodiment shown in [Fig.5], the prestressing element putting the test body 1.1 under tension is a nut 1.1.7 which is engaged on a threaded rod 1.1.12 extending the end section 1.1.2 and which bears against the second leg 2.2.2 by means of a washer 1.1.8.

[0047] In [Fig. 5], the test body 1.1 comprises two superimposed central sections 1.1.3 whose principal faces are parallel to each other. The central sections 1.1.3 are positioned symmetrically with respect to the central axes of the end sections 1.1.1, 1.1.2 and each carries a transducer 1.2.

[0048] We can also see the housing provided in the end section 1.1.1 to receive the connector and two conduits 1.1.6 opening on one side into the housing of the connector and on the other side in the vicinity of each central section 1.1.3 to connect each transducer to the connector.

[0049] In the variant of [Fig.6], the sensor 1 is identical to that of [Fig.5] except that the test body 1.1 comprises only a single central section 1.1.3 and a single conduit 1.1.6.

[0050] In the variant of [Fig. 10], the test specimen 1.1 of [Fig. 5] is equipped with a protective sleeve 1.3 arranged around a portion of the test specimen 1.1 extending between the tabs 2.2 so as to hermetically seal this portion of the test specimen 1.1. This sleeve 1.3 has two ends, each provided with a opening receiving an annular sealing gasket to fit the shape of the test body 1.1 and seal the inside of said sheath 1.3. Alternatively, the sheath 1.3 could extend only around the central section 1.1.3 to protect the transducer 1.1.

[0051] With reference to Figure 7, according to the third embodiment, the test body 1.1 takes the form of a U-shaped profile bar, having a central web from which two parallel fins project. The U-shaped profile bar comprises two end sections 1.1.1, 1.1.2 on either side of a central section 1.1.3 that is thinner than the end sections 1.1.1, 1.1.2. More precisely, the web has a constant width along the entire length of the test body 1.1, but the fins have a height that decreases from the end sections 1.1.1, 1.1.2 to the middle of the central section 1.1.3. This thinning, as before, is intended to concentrate the deformation forces in a small area housing the transducer 1.2. The fins are provided with two holes 1.1.11 at the level of the two end sections 1.1.1, 1.1.2 of the test body 1.1, said holes 1.1.11 passing through each of the two fins perpendicularly to the longitudinal direction of the test body 1.1. .

[0052] In this third embodiment, the free ends of the legs 2.2 are each pierced with a hole 2.2.3, said holes 2.2.3 passing through the fins perpendicular to the longitudinal direction of the test body 1.1.

[0053] The U-shaped profiled bar is positioned so that the two parallel fins are placed on either side of the lugs 2.2 of the housing 2 with the holes 1.1.11 of the fins opposite the holes 2.2.3 of the lugs 2.2 and that pins 2.2.4 can be inserted into the holes 2.2.3, 1.1.11 opposite.

[0054] In this configuration, the prestressing of the test body 1.1 is initiated by a slight undersizing of the spacing between the holes 1.1.11 of the test body 1.1. Indeed, the spacing between the holes 1.1.11 of the test body 1.1 is less than the spacing between the holes 2.2.3 of the end sections of the legs 2.2, requiring tensioning of the test body 1.1 during the installation of the pins 2.2.4.

[0055] This tensioning of the test body 1.1 is carried out by means of a tool such as a lever provided with two lugs spaced apart from each other. After the pin 2.2.4 is placed in the end section 1.1.1 and the tab 2.2.1, the lugs of the lever are inserted respectively into an auxiliary hole hl of the second tab 2.2.2, which passes perpendicularly through said second tab 2.2.2 with respect to the test body 1.1, and into an auxiliary hole h2 passing through the two fins of the profiled bar. The lever is then tilted to apply a tensile force to the test body 1.1 by bearing against the tab 2.2.2, causing a tensile deformation of the test body 1.1, allowing the holes 1.1.11 of the section to be aligned. end 2.2.2 with hole 2.2.3 of the second leg 2.2.2. This alignment then allows the positioning of the second pin holding the pre-stressed test body 1.1.

[0056] With reference to [Fig.8], according to a fourth embodiment, the test body 1.1 is of a hybrid shape incorporating certain characteristics of the second and third embodiments.

[0057] The test body 1.1 is, as in the third embodiment, a profiled bar having a U-shaped cross-section, with two parallel fins and a central web, and the tab 2.2.1 is identical in shape to that of the third embodiment. Thus, the end section 2.2.1 is positioned astride the tab 2.2.1 so that the two parallel fins are placed on either side of the tab 2.2.1. The end section 1.1.1 is articulated to the tab 2.2.1 by a pin or axle passing through the end section 1.1.1 and the tab 2.2.1.

[0058] The lug 2.2.2 is identical to the lug 2.2.2 of the second embodiment, and the second end section 1.1.2 is extended by a threaded rod 1.1.12 which is received in the hole of the lug 2.2.2 and cooperates with a nut 1.1.7 bearing against the lug 2.2.2 to tension the test body 1.1. It is understood that when the test body 1.1 is placed on the housing 2, the threaded rod 1.1.12 is inserted into the hole of the lug 2.2.2, the end section 1.1.1 is positioned astride the lug 2.2.1 and is pinned to the lug 2.2.1. The nut 1.1.7 is then screwed onto the threaded rod 1.1.12 to tension the test body 1.1.

[0059] The fifth embodiment of [Fig.9] is close to the fourth embodiment in principle but mixes the first embodiment and the third.

[0060] The test body 1.1 comprises a finned end section 1.1.1 as in the third embodiment, a flat central section 1.1.3, and an end section 1.1.2 having a threaded hole to receive the end of a tensioning screw 1.1.10 as in the first embodiment. Correspondingly, the tab 2.2.1 and the method of attaching the end section 1.1.1 to it conform to the third embodiment, and the tab 2.2.2 and the method of attaching the end section 2.2.2 to it conform to the first embodiment.

[0061] The core of the end section 2.2.1 has a portion perpendicular to the rest of the test body 1.1 and connected to the fins. This portion of the core is equipped with an electrical connector 1.1.4 suitable for connecting the transducer 1.2 to the electronic processing unit.

[0062] Of course, the invention is not limited to the embodiments described but encompasses any variant falling within the scope of the invention as defined by the claims.

[0063] In particular, although here in some embodiments, screw / nut type tensioning means are provided, it is possible to use other similar technical solutions such as a "toggle latch" to tension a test body 1.1 in a repeatable manner.

[0064] The thinned portion 1.1.1 of the test body 1.1 can accommodate a single transducer, two transducers or more than two transducers.

[0065] The proof body 1.1 may include one or more thinned parts to receive one or more transducers.

[0066] Although, in the first embodiment, the geometry element is a key 1.1.13 linked to the test body 1.1 collaborating with the geometry of the leg 2.2 to block said test body 1.1 in rotation, this geometry element may be a flat 1.1.5 present on said test body 1.1 collaborating with a flat surface of one of the legs 2.2 or directly of the housing 2, it is also possible that the geometry element is not directly a part of the test body 1.1 but is linked to another element of the sensor 1 such as the electrical connector 1.1.4 for example.

[0067] Although here the direction of the fins is not specified in the embodiments comprising a test body 1.1 having a U-shaped profiled bar, it is possible that this profiled bar is positioned with the fins extending from the core towards the housing 2, or in the opposite direction.

[0068] Although the test body 1.1 is equipped with an electrical connector 1.1.4, the connection to the transducer 1.2 may be made in another way, possibly wirelessly. Thus, it is possible that there may not be an electrical connector 1.1.4 as illustrated in Figures 2, 3, 4, 7, and 8.

[0069] It is possible to use a protective sheath for all embodiments.

Claims

Demands

1. A braking device for an aircraft wheel 101, comprising at least one stack of rotor (8.1) and stator (8.2) discs (8), an actuator housing (2), an actuator (13) mounted in the actuator housing (2) for exerting a pressing force on the stack of discs (8), the actuator housing (2) comprising a connecting portion (3.1) to the landing gear and a receiving portion (3.2) for the actuator and being provided with a first strain sensor (1), characterized in that the first strain sensor (1) comprises a test body (1.1) having a first end (1.1.1) mechanically and removably fixed to the connecting portion (3.1) and a second end (1.1.2) mechanically and removably fixed to the receiving portion (3.2), and a transducer (1.2) fixed to the test body (1.1) for measuring a strain of the test body (1.1).

2. Device according to claim 1, wherein the test body (1.1) is held under tension on the housing (2).

3. Device according to any one of the preceding claims, wherein the housing (2) comprises two radially projecting tabs (2.2) having free ends between which the test body (1.1) extends.

4. Device according to claim 3, wherein the free end of each of the legs (2.2) is drilled with a hole to receive one end of the test body (1.1), the holes being coaxial.

5. Device according to any one of claims 3 and 4, wherein at least one end of the test body (1.1) is provided with an axial stop bearing against one of the lugs (2.2) and at least one end of the test body (1.1) includes a thread, cooperating with a pre-stressing member, allowing tensioning of the test body (1.1).

6. Device according to any one of claims 3 to 5, wherein the free end of at least one of the legs (2.2) is pierced with a hole perpendicular to the test body, the test body being connected to said at least one of the legs by a pin (2.2.4) received in the perpendicular hole, said at least one of the legs and the test body being arranged to cooperate with a tool for tensioning the test body before the introduction of the pin (2.2.4) into the perpendicular hole.

7. Device according to any one of the preceding claims, wherein the test body (1.1) of the first sensor (1) takes the form of a bar having end sections (1.1.1, 1.1.2) having an axis of symmetry, on either side of a central section (1.1.3) having a thinner section (1.1.1) hosting the transducer (1.2).

8. Device according to any one of the preceding claims, wherein an electrical connector is positioned at one end of the first sensor and a hole extends from said end of the test body to the transducer (1.2) to receive at least one electrical wire connecting said electrical connector to said transducer (1.2).

9. Lander comprising a wheel equipped with a braking device according to any one of the preceding claims, the connecting part of the housing being rotationally linked to the lander.

10. Aircraft comprising the landing gear according to claim 9.

Images