A torque. In particular, the invention relates to a torsional torque meter for measuring torque of a rotating element, in particular in a turbine engine of an aircraft.

2. BACKGROUND

the torsion torque are torque measuring devices whose operating principle is to measure the twist of a first shaft, said transmission shaft subject to torque to be measured, and compare an angular deformation due to this torsion between drive shaft and a second shaft, said reference shaft, which is not subjected to the torque to be measured. The comparison allows to deduce the torque to be measured.

In particular, the measurement of the angular deformation is carried out by adding on each read teeth shaft forming a phonic wheel, and the acquisition by the passage of each tooth sensor before the sensor. In the absence of torque on the drive shaft, a read tooth of the drive shaft and a reference shaft reading tooth are spaced a certain distance. When the drive shaft is subjected to a torque, the resulting twist causes the deformation of the shaft and moving a read tooth of the drive shaft with respect to a reference shaft reading tooth . This displacement causes a variation of the time of passage of the teeth past the sensor with respect to a tooth of the reference shaft, and allows the

When using such a torque in an environment in which there is large temperature variations, for example in a turbine engine of an aircraft, the torsion of the drive shaft may be different, for the same torque to be measured depending on the temperature of the transmission shaft. Thus, the measured angular deformation varies in the same way, and the measured torque has a greater or lesser error depending on the temperature to which the torque meter has been calibrated.

To prevent measurement errors due to variable temperature at which the torque is subject, several solutions have been proposed.

In particular, a proposed solution is to use reading inclined teeth on the tone wheel, allowing to reduce the influence of temperature. However, the correction made by tilting the playing teeth is constant and does not depend on the couple. This correction is only optimized for torque range and introduces an error outside this range.

Another solution is to place the torque in a confined environment so that it does not undergo temperature variations. However, confinement of the torque reduces temperature variations, but does not remove them completely. The measurement error is not corrected and thus the measurement accuracy is affected.

The demands of torque measurements more precise led the inventors to find new solutions in response to these problems.

3. Objectives of the invention

The invention aims to alleviate at least some of the disadvantages of known torsion torque.

In particular, the invention aims to provide, in at least one embodiment of the invention, a torque enabling torque measurement with high accuracy.

The invention also aims to provide, in at least one embodiment, a torque whose torque measurement is not affected by temperature variations.

The invention also aims to provide, in at least one embodiment of the invention, a torque that can be easily adapted to several aircraft turbine engines.

4. Summary of the Invention

To do this, the invention concerns a torque to torsion, comprising a first shaft, said transmission shaft subject to torque to be measured, a second shaft, said reference shaft, and a device for measuring an angular deformation between 'driveshaft and the reference shaft, said angular deflection being representative of the torque to be measured,

characterized in that the transmission shaft comprises a bore forming an inner wall and extending from one end of the transmission shaft, said input shaft at an opposite end, said output shaft, and in that the torque comprises:

a containment vessel in temperature of the first and second shaft, and

a circulation circuit of a fluid comprising:

a portion constituted by said bore of the drive shaft,

an injector of fluid into the bore at said input shaft, and

a temperature sensor, said main temperature sensor, adapted to measure the temperature of fluid in the circulation circuit of the fluid, the measured fluid temperature being for correction of the torque measurement.

A torque to torsion of the invention thus allows to impose a temperature at the transmission shaft with one hand containment permits to significantly reduce the influence of the outside temperature to the transmission shaft, and on the other hand to the fluid flow in the bore formed in the transmission shaft to impose on the fluid temperature driveshaft which is known as measured by the primary sensor temperature. The temperature of the transmission shaft being well known as very close to the fluid temperature, it is possible to foresee its influence on the angular deflection measured (due to the torsion of the drive shaft), and thus of

Measuring the temperature of the fluid by the temperature sensor is simpler than measuring the temperature of the transmission shaft.

In addition, a torque meter according to the invention allows to simplify the procedures called conformation or calibration in which the parameters are determined

conformation allowing accurate measurement of the torque in a situation of actual operation, for example when the torque is installed in an engine. These shaping parameters are for example the relationship between the temperature of the transmission shaft and the measured angular deformation, allowing to deduce the torque. In the prior art, this configuration should be performed in the engine in which the torque to be installed. In case of substantial modification of the engine, the torque of the conformation must be performed again. In the invention, thanks to the containment and temperature imposed by the fluid, the conformational parameters are independent of the engine wherein the torque meter is installed and the shaping procedure is therefore simplified,

The fluid flow path and the temperature sensor are part of a device for correcting the torque measurement. This device for correcting the torque measuring comprises a computer which, from the temperature measurement provided by the temperature sensor, performing the correction of the torque measurement.

Each transducer may further comprise a plurality of temperature sensors. However, the fluid temperature varies slightly due to the containment, a single temperature sensor is generally required.

Advantageously and according to a first variant of the invention, the driveshaft and the reference shaft are coaxial, the transmission shaft being disposed inside the reference shaft.

In this aspect of the invention, the bulk of the torque is greatly reduced. The assembly formed by the drive shaft and the reference shaft is sometimes referred to shaft torque.

Advantageously and according to a second variant of the invention, the driveshaft and the reference shaft are coaxial, the reference shaft being disposed inside the transmission shaft and the fluid flowing between the inner wall of the transmission shaft and an outer wall of the reference shaft.

According to this aspect of the invention, the bulk of the torque is greatly reduced, and the torque is configured so that the fluid is in contact with the inner wall of the drive shaft, so as to regulate the temperature of the shaft transmission, despite the presence of the reference shaft inside the drive shaft, that is to say in the bore of the driveshaft.

Advantageously and according to the invention, the fluid is oil and the fluid circulation circuit is a hydraulic circuit.

In this aspect of the invention, the oil is a widely used industrial fluid whose flow circuits are controlled, allowing a good heat exchange with the driveshaft to impose its temperature.

In addition, when using the torque in a turbine engine, it is possible to reuse at least part of the oil circulation circuit (also called hydraulic circuits) existing. In particular, the main temperature sensor can be an existing temperature sensor in the turbine engine for further use.

According to other embodiments of the invention, the fluid may be the fuel (kerosene for example), a gas (air for example), etc.

Advantageously and according to the invention, the main temperature sensor is adapted to measure the temperature of the fluid at the inlet of the shaft.

According to this aspect of the invention, the main temperature sensor is used to find the temperature at the inlet of the shaft which is close to the temperature that will be imposed to the shaft for the movement of the fluid in the bore of the tree.

In addition, when using the torque in a turbine engine, a temperature sensor is frequently present at the beginning of the hydraulic circuit before circulating in the various equipment, and can therefore be used for the torque without having to install a additional temperature sensor which would be redundant.

Advantageously and according to the latter aspect of the invention, the torque comprises an auxiliary temperature sensor adapted to measure the fluid temperature at the outlet of the tree.

According to this aspect of the invention, adding a second sensor at the outlet of the shaft to detect any variation in temperature of the fluid after passing through the transmission shaft. This variation may provide containment in the event of fault trees and can thus be taken into account and corrected by the second sensor. The temperature measurement is well refined and more robust.

Advantageously and according to the invention, the bore comprises two bore sub-sections connected by a transition zone, a first sub-section of the inlet side of the shaft, and a second sub-section on the side of the output shaft, the second sub-section having a diameter smaller than the diameter of the first subsection.

According to this aspect of the invention, reducing the diameter of the bore permits a better circulation of the oil through the formation of a chicane at the transition zone.

Advantageously and according to the latter aspect of the invention, the second sub-section is offset from the first sub-section and the bore.

The invention also relates to a turbomachine comprising a rotating shaft, characterized in that it comprises a torsion torque according to the invention adapted to measure the torque of the rotating shaft.

The invention also relates to a torque meter and a turbomachine characterized in combination by all or some of the features mentioned above or below.

5. List of Figures

Other objects, features and advantages of the invention will appear on reading the following description given by way of non-limiting and which refers to the appended figures in which:

Figure 1 is a schematic view in partial section of a torsion torque according to a first embodiment of the invention,

Figure 2 is a schematic sectional view of a portion of a torsional torque according to a second embodiment of the invention.

6. Description of an embodiment of the invention

The following achievements are examples. Although the description refers to one or more embodiments, this does not necessarily mean that each reference is to the same embodiment, or that the specifications apply only to a single embodiment. Simple features of different embodiments may also be combined to provide other embodiments. In the figures, scales and proportions are not strictly complied with, for purposes of illustration and clarity. In particular, the lengths of different trees shown may vary according to different embodiment of the invention.

1 shows schematically in partial section a torque meter 100 to torsion according to a first embodiment of the invention.

Each transducer comprises two shafts, a first shaft said shaft 12 of transmission and a second shaft said shaft 14 as a reference. In this first embodiment, the transmission 12 and the shaft 14 are coaxial reference shaft 12 and the transmission shaft is disposed within the shaft 14 as a reference.

The transmission shaft 12 is subjected to the torque to be measured by the torque meter 10 in torsion, while the reference shaft 14 is not subjected. Thus, the transmission shaft 12 undergoes a representative torsion torque measuring.

The shaft 12 and transmission shaft 14 of reference each comprise a wheel 16a, 16b phonic comprising teeth 18 of reading, two wheels 16a, 16b are configured for a read sensor 20 detects the passage of teeth 18 readings of the two wheels 16a, 16b phonic. Reading is performed for example optically or magnetically, and determines the time between the passage of each tooth and thereby the angular deformation between the shaft 12 and transmission shaft 14 as a reference due to the fact that only '12 transmission shaft is subjected to torque

measure. The angular deformation is representative of the torsion of the shaft 12 of transmission, for determining the torque to be measured. The wheels 16a, 16b and the sound read sensor 20 form a device for measuring an angular deformation.

To reduce the influence of temperature on the torque meter 10, in particular the influence of temperature on the torsion shaft 12 of transmission, the torque meter 10 comprises firstly an enclosure 22 of containment temperature to remove or limit the influence of external temperature torque meter 10, and on the other hand a circulation of a fluid circuit to impose on the transmission shaft 12 to a temperature, that of a fluid therethrough.

The fluid flow path includes a portion which is constituted by a bore 24 of the shaft 12 of transmission, so as to circulate the fluid through the bore 24. The bore 24 forms an inner wall 26 and extends one end of the shaft 12 of transmission, said inlet 28 of the shaft at an opposite end, called the outlet 30 of the shaft. The bore 24 may comprise several different diameters of sub-sections connected by transition zones 31 of forming one or more baffles, so as to improve fluid flow.

The fluid thus flows through the bore 24 and into contact with the internal wall 26, and thus allows to impose its temperature at the shaft 12 of transmission by heat transmission. The containment of the transmission shaft 12 by the containment further ensures that any temperature fluctuations of the transmission shaft 12 are linked only to a change in the fluid temperature. The path of the fluid in the bore 24 is shown by an arrow 12 through the transmission shaft between the inlet 28 and the outlet 30 of the shaft.

The fluid is injected into the bore 24 at the inlet 28 of the shaft, through an injector 32 of the fluid circulation circuit. The injector 32 allows the diffusion of the fluid on the inner wall 26 of the bore, and the flow of fluid along the bore 24. Upon exiting bore 24, the fluid continues its flow through the circuit fluid flow.

To determine the fluid temperature, the fluid flow path comprises at least one temperature sensor: In this embodiment, a

Main sensor 34 temperature is disposed near the inlet 28 of the shaft, prior to the injector 32, so as to measure the temperature of the fluid at the inlet 28 of the shaft.

The temperature of the fluid measured and allows a correction of the measured torque of the torque meter 10: twisting of the transmission shaft 12 is variable depending on its temperature, about this temperature to determine the change in torsion and derive the correction to the torque determined by the reading sensor 20 of wheels 16a, 16b phonic, so as to obtain a measurement of precise torque. This calculation of torque from the measurement of the sensor 20 reading and the temperature measured by the main sensor 34 temperature may be done for example in a computer (not shown).

The shaft 14 reference requires no fluid flow path because it is not subject to the couple and therefore presents no twisting variable depending on its temperature.

2 schematically shows a part of a torque 200 to torsion according to a second embodiment of the invention.

As in the first embodiment, the torque comprises two shafts, a shaft 12 and a transmission shaft 14 by reference. In this second embodiment, the shaft 12 of transmission 14 and the reference shaft are coaxial and unlike the first embodiment, it is the 14 reference shaft which is disposed within the shaft 12 transmission. To simplify the figure, the parts of the torque meter 10 comprising the phonic wheels are not shown as similar to the first embodiment.

Thus, the flow of fluid injected by the injector 32 is made in the bore 24 between the wall 26 of the inner transmission shaft 35 and an outer wall of the shaft 14 by reference. Arrows in the figure represent the path of the fluid in the torque.

In addition, in this second embodiment, the torque sensor 10 comprises a main 34 temperature and an auxiliary temperature sensor 36 to a second measurement of the temperature at the outlet of the tree. This sensor auxiliary temperature 36 refines the measurement and is useful when

poor containment of the shaft 12 of transmission 22 by the enclosure confinement, resulting in a variation of the temperature of the transmission shaft 12 due to an external element. In practice, an imperfect confinement of the transmission shaft 12 results in a temperature variation between the value at the entrance of the shaft, measured by the main sensor 34 temperature and the value at the output of the shaft, measured by the auxiliary temperature sensor 36, which remains low. The measured temperature value used to correct the measurement of torque meter 10 may be for example the average of the temperatures measured at the inlet and outlet of the shaft, to take account of the small variation.

The fluid used in the first and second embodiment is for example oil. In particular, when using a torque according to one of the embodiments in an aircraft turbine engine, the turbine engine includes a hydraulic oil circuit for supplying various equipment. The oil of this hydraulic circuit can be used for supplying the torque of the fluid circulation circuit. In addition, elements of the hydraulic circuit can be reused, for example an oil temperature sensor distributed by the hydraulic circuit can be used as the main torque sensor of the temperature, if the oil is not subjected to temperature variation between this sensor and the input of the shaft.

According to other embodiments, the fluid used may for example be fuel (eg kerosene) or gas (including air), which are also sometimes available in a turbine engine of an aircraft.

CLAIMS

Neck plemètre torsion, comprising a first shaft, said shaft (12) of transmission, subject to the torque to be measured, a second shaft, said shaft (14) reference and a measurement device of an angular deformation between shaft (12) and the transmission shaft (14) of reference, said angular deflection being representative of the torque to be measured,

characterized in that the shaft (12) for transmitting comprises a bore (24) forming a wall (26) internal and extending from one end of the shaft (12) of transmission, said inlet (28) of shaft at an opposite end, called the outlet (30) of the shaft, and in that the torque comprises:

an enclosure (22) confining the temperature of the first and second shaft, and

a circulation circuit of a fluid comprising:

- a portion constituted by said bore (24) of the shaft (12) of transmission,

an injector (32) of fluid in the bore (24) at said inlet (28) of the shaft, and

a r capteu temperature, said sensor (34) Main temperature, adapted to measure the temperature of fluid in the circulation circuit of the fluid, the measured fluid temperature being for correction of the torque measurement.

2. Torque according to claim 1, characterized in that the shaft (12) and the transmission shaft (14) of reference are coaxial, the shaft (12) for transmitting being disposed within the shaft (14) reference.

3. Torque according to claim 1, characterized in that the shaft (12) and the transmission shaft (14) of reference are coaxial, the shaft (14) of reference being isposé within the shaft (12) for transmitting and fluid flowing between the wall (26) of the inner shaft (12) and a transmission wall (35) of the outer shaft (14) by reference.

4. Torque according to one of claims 1 to 3, characterized in that the fluid is oil and the fluid circulation circuit is a hydraulic circuit.

5. Torque according to one of claims 1 to 4, characterized in that the sensor (34) Main temperature is adapted to measure the fluid temperature at the inlet (28) of the shaft.

6. Torque according to claim 5, characterized in that it comprises a sensor (36) auxiliary temperature, adapted to measure the fluid temperature at the outlet (30) of the shaft.

7. Torque according to one of claims 1 to 6, characterized in that the bore (24) comprises two bore sub-sections connected by a zone (31) of transition, a first sub-section on the side of input (28) of the shaft, and a second sub-section towards the outlet (30) of the shaft, the second sub-section having a diameter smaller than the diameter of the first subsection.

8. Torque according to claim 7, characterized in that the second sub-section is offset from the first sub-section and the bore (24).

9. A turbomachine comprising a rotating shaft, characterized in that it comprises a torque meter (10a, 10b) twisting according to one of claims 1 to 8, adapted to measure the torque of the rotating shaft.