Rotating machine comprising a casing and a shaft

Abstract

Disclosed is a rotating machine (6) comprising: - a casing (8); and - at least one gauge (16) that is attached directly to the casing and arranged to detect a load applied to the casing at a distance from the gauge and / or a variation in a shape of the casing.

Description

[0001] Rotating machine comprising a casing and a shaft

[0002] FIELD OF THE INVENTION

[0003] The invention relates to rotating machines, in particular hydraulic machines.

[0004] STATE OF THE ART

[0005] Machines for transmitting rotary motion for vehicles or machines are known, for example hydraulic or electrical machines, which are motors forming part of a motion transmission chain and comprise a fixed part and a rotating part between which are placed one or more bearings comprising rollers. Each motor is connected by its fixed part to a chassis and to a source of electrical or hydraulic energy, and by its rotating part to an element to be driven. The energy source may be a storage battery and its control electronics, or a hydraulic pump.

[0006] For example, it is a hydraulic wheel motor in which the fixed part has hydraulic lines and a rotating part has a cylinder block with pistons and connected to an output shaft receiving a wheel. The pistons of the cylinder block are in contact with a corrugated cam carried by the fixed part. Pressurizing the machine allows the pistons to move on the cam, which generates the rotational movement of the engine. The machine has a casing including parts for fixing to the frame, such as flanges.

[0007] Since the machine acts as a wheel motor, the vehicle or machine rests on the machine's structure, while the machine's bearing provides the rotational movement while carrying the necessary weight or transverse forces. The machine's bearing therefore absorbs not only the rotational torque but also the radial and axial forces due to loads external to the machine. However, these forces and loads can disrupt the machine's control.

[0008] One aim of the invention is to improve the control of rotating machines.

[0009] STATEMENT OF THE INVENTION

[0010] According to the invention, a rotating machine is provided comprising: - a casing, and

[0011] - at least one gauge directly attached to the casing and arranged to detect a stress applied to the casing at a distance from the gauge and / or a variation in a shape of the casing.

[0012] Thus, the detection of stress or shape variation takes place directly at the level of the casing or frame, therefore as close as possible to the bearing formed by the machine and in real time. This detection is therefore carried out with good reliability. The invention provides access to information, some of which was previously difficult to obtain accurately. It uses the deformations of the casing to measure loads, including during use of the machine.

[0013] If necessary, measurement from two gauges along two axes allows a vector composition (ideally four gauges on two axes, or three gauges on three axes, etc.). Depending on the elongation or compression of each gauge, all the components of the forces tending to deform the casing are determined.

[0014] If we are dealing with a machine comprising wheels each driven by a machine according to the invention, the latter makes it possible to control the traction of the machine for each wheel. It can be used to manage the traction of the machine, in particular to control the traction on the engine in question, depending on whether the wheel is heavily loaded or lightly loaded. For example, to perform a crossing or an anti-skid function, the invention makes it possible to drive less a wheel that has little support, and vice versa, for example, for a wheel in a rut or on an obstacle. It also makes it possible to drive the wheels of the machine in a differentiated manner on a slope by choosing the distribution of the drive between the front and the rear or between the right and the left. The same applies to braking.The invention allows instant control on the machine, which is more precise than a measurement on suspensions, on a chassis or by an inertial unit, and makes it possible to avoid errors.

[0015] It allows for very low speed operation (or creep drive in English) to be controlled, for example, to overcome a specific obstacle, such as a rut or a curb. It also allows traction to be adapted to a variable load on the machine, such as a sprayer tank, a grain silo or a spreader load being emptied. It also allows unequal load widths to be managed on the machine, and also to monitor the load on each wheel of the machine depending on slopes or inclines.

[0016] Thanks to this load measurement, the invention makes it possible to improve the machine's control, to improve the distribution of traction torques on several wheels if necessary, as well as slope stability. It also makes it possible to better predict the machine's lifespan. It makes it possible to improve the machine's control by having precise information on its operation and condition.

[0017] The processing of the signals provided by the gauge(s) to determine the forces is carried out by automated means which can be incorporated into the automated control means of the machine, or even of the machine itself.

[0018] The invention provides access to information that has previously been difficult to obtain using traditional measuring equipment, which is bulky and can only be used on a fixed installation or test bench. It does not require the addition of bulky additional parts to the machine.

[0019] The placement of the gauge(s) on the casing allows measurements to be taken on a unique part characteristic of each machine model.

[0020] The invention is not intrusive. It is included in the machine's footprint. It can be standard on a machine (it will remain to be calibrated according to the machine). It can be easily dedicated in that the gauges would be placed according to the positioning of the machine, for example the angular position of the engine on the chassis of the machine.

[0021] The instrumentation used does not pose any problems in terms of sizing, oil compatibility, pressure resistance or sealing. The gauge(s) do not pose any clogging problems due to metal pollution, nor do they disrupt the force transmission chain within the machine.

[0022] In particular, the invention provides a rotating hydraulic machine comprising:

[0023] - a casing,

[0024] - a cylinder block having radial housings on an axis of the machine,

[0025] - pistons received in the respective housings, - a cam forming a rolling track for rollers connected to the respective pistons, and

[0026] - at least one gauge directly attached to the casing and arranged to detect a stress applied to the casing at a distance from the gauge.

[0027] The invention also provides a rotating machine, in particular a hydraulic machine, comprising:

[0028] - a casing, and

[0029] - at least one gauge directly attached to the casing and arranged to detect a variation in a shape of the casing.

[0030] The machine can be predicted to be hydraulic.

[0031] But otherwise it could be an electric machine.

[0032] It can be a motor or a pump.

[0033] It can be expected that the gauge or at least one of the gauges:

[0034] - includes a piezoelectric sensor;

[0035] - is a resistive gauge;

[0036] - is a multiaxial gauge;

[0037] - is located in a vertical plane occupied by an axis of rotation of the machine, and / or

[0038] - is located in a horizontal plane occupied by an axis of rotation of the machine.

[0039] The words "strain gauges" and "extensometry gauge" are considered synonymous here. The strain is accessed if the strain gauge has been calibrated. For example, if the elongation of the material is known, the strain is known. Then, in subcategories, "resistive gauge" and "piezoelectric gauge" are two ways of measuring strain.

[0040] The machine may be provided with two gauges located in a plane occupied by an axis of rotation of the machine, the gauges being located on either side of the axis.

[0041] We can predict that the plane is vertical or horizontal.

[0042] It can be provided that the machine comprises: - two gauges located in a first plane occupied by an axis of rotation of the machine, the gauges being located on either side of the axis; and

[0043] - two gauges located in a second plane occupied by the axis, the gauges of the second plane being located on either side of the axis; the two planes being intersecting.

[0044] Thus, for a vehicle or a wheeled machine, four gauges on two axes for a wheel allow all the stresses due to the wheel to be measured. For another machine (driving an arm for example), four gauges on two perpendicular axes also allow all the components of the forces to be easily seen. In all cases, a vector composition of the measurements allows all the forces to be determined, even if one axis is not vertical and if the axes are not absolutely perpendicular or if there are more than four gauges.

[0045] In the case where there are few gauges, for example two gauges on two axes at 90°, the use of rosette or multiaxial gauges which give the measurements oriented in the plane at the location of the gauge makes it possible to know all the information including for example the bending torque of the casing.

[0046] The machine may be expected to include at least one of the following features:

[0047] - it comprises at least two gauges extending in the same plane perpendicular to an axis of the machine;

[0048] - it comprises three gauges forming a triangle as seen from one end of a shaft of the machine, the shaft being in the triangle;

[0049] - the gauge or at least one of the gauges is fixed directly to a fixing flange of the machine to an element external to the machine;

[0050] - the gauge or at least one of the gauges extends against a circumferential face of the flange oriented in the direction opposite to an axis of rotation of the machine or in the direction of the axis of rotation;

[0051] - the face extends back from an outer circumferential edge of the flange;

[0052] - the flange comprises at least one support extending in projection from an axial face of the flange perpendicular to the axis of rotation, the support having the circumferential face and extending over only a fraction of a circumference of the flange so as to provide on the axial face of the flange one or more clearances in a circumferential extension of the support, the or each clearance comprising one or more electronic components connected to the gauge or gauges;

[0053] - the flange comprises a protective member, such as a covering or a hood, covering the gauge(s) and / or the clearance(s);

[0054] - the gauge or at least one of the gauges is located at a bearing of the machine; and

[0055] - the gauge or at least one of the gauges is located at an area between a bearing of the machine and a flange for attaching the machine to an element external to the machine.

[0056] For example, the gauge(s) is glued to the crankcase.

[0057] The housing may have a flat surface, a cylindrical surface, or facets for receiving the gauge.

[0058] It may be provided that the gauge or at least one of the gauges is located on an external face of the casing.

[0059] Thus, detection takes place outside the Faraday cage that some machines constitute. This allows wireless transmission of detection information outside the machine.

[0060] It may be provided that the gauge or at least one of the gauges extends against a facet of planar or cylindrical shape, the facet being located in a face of the casing having a shape other than a planar or cylindrical shape, the gauge forming in particular a ribbon.

[0061] Such a facet makes it easier to install the gauge, especially when it forms a ribbon. Indeed, such a gauge is flexible and can bend but not stretch. It cannot therefore be fixed to a left surface. In the presence of a left casing face (for example, conical), a facet can therefore be provided in the face as indicated above, for example by machining it into the face. This also applies when several gauges forming a continuous ribbon must be fixed to the casing.

[0062] The machine can be expected to include:

[0063] - an annular-shaped cam having lobes on one face, in particular an internal face, of the cam, and - pistons extending opposite the lobes.

[0064] The invention also provides a device comprising:

[0065] - a main part and

[0066] - a member mounted to move relative to the main part by means of a machine according to the invention.

[0067] The invention also provides a machine comprising a chassis and wheels, at least one of the wheels being connected to the chassis by a machine according to the invention.

[0068] Furthermore, according to the invention, a method is provided in which a stress applied to the casing at a distance from a detection zone and / or a variation in a shape of the casing is detected at least once on a casing of a rotating machine.

[0069] In particular, the invention provides a method in which, in a machine comprising:

[0070] - a casing,

[0071] - a cylinder block having radial housings on an axis of the machine,

[0072] - pistons received in the respective housings, and

[0073] - a cam forming a rolling track for rollers connected to the respective pistons, a stress applied to the casing at a distance from a detection zone is detected at least once on the casing.

[0074] The invention also provides a method in which a variation in a shape of the housing is detected at least once on a casing of a rotating machine.

[0075] The method may also have at least one of the following characteristics:

[0076] - the machine is stopped during the detection step or one of the detection steps;

[0077] - the machine is running during the detection step or one of the detection steps;

[0078] - the amplitudes of at least two stresses or two deformations are measured in two respective predetermined zones of the casing and at least one intensity of a force or torque exerted on the machine from outside the machine is determined by means of the amplitudes; and

[0079] - the machine is controlled based on the intensity or torque. In particular, detection on the machine when stationary on flat ground allows the weight of the machine to be measured and the process to be configured. A software acquisition step when stationary allows this calibration.

[0080] Finally, according to the invention, there is provided a method for controlling a machine comprising two rotating machines connecting wheels to a chassis of the machine, in which:

[0081] - the wheels are controlled individually from each other and

[0082] - each wheel is controlled by means of a method according to the invention as a function of at least one intensity of a force or torque exerted on the wheel.

[0083] Indeed, knowing the load on each machine, we are able to distribute the driving force between the wheels for better grip or better traction.

[0084] These steps are, for example, implemented in automated processing means by means of a computer program comprising code instructions capable of controlling the steps of the process.

[0085] DESCRIPTION OF FIGURES

[0086] We will now present embodiments of the invention by way of non-limiting examples in support of the drawings in which:

[0087] - Figure 1 is an elevational view of a machine comprising motors forming machines according to one embodiment of the invention;

[0088] - figure 2 is a simplified axial sectional view of one of the engines of the machine of figure 1;

[0089] - figure 3 is a view similar to figure 2 showing another embodiment of the engine;

[0090] - figures 4 and 5 are two views illustrating two circumstances of use of the engine of figure 2;

[0091] - figure 6 is a view similar to figure 2 showing another embodiment of the engine;

[0092] - figures 7 to 9 are axial sectional views of machines according to embodiments of the invention showing different examples of positioning of the gauges;

[0093] - Figure 10 illustrates a gauge attached to the housing in one embodiment of the invention; and - Figures 11 and 12 illustrate part of a machine according to another embodiment of the invention

[0094] Figure 1 illustrates a device forming a machine 2 according to one embodiment of the invention. In this case, it is an excavator, but the invention applies to many other types of machines, for example tractors, trailers, etc. It also applies to devices without wheels and in which a load is supported by means of a machine according to the invention. This may, for example, be a robot equipped with at least one handling arm. Figure 1 illustrates a reference frame in which the x direction is the horizontal forward direction of the machine 2, y is the transverse horizontal direction, and z is the vertical direction.

[0095] In the present example, the machine 2 comprises a chassis 3 or main part and wheels 4, here four in number, this number not being limiting. Each wheel 4 is connected to the chassis 3 by its own rotating machine 6 according to the invention forming a motor, these machines 6 therefore being here four in number. In this case, these are hydraulic machines.

[0096] With reference to Figure 2, each machine 6 comprises a casing 8 comprising a wall 11 having an external face 12 exposed to the external environment and an internal face 14 oriented towards the internal components of the machine.

[0097] This machine comprises gauges 16 directly attached to the casing 8 and arranged to detect a stress applied to the casing at a distance from the gauge and / or a variation in a shape of the casing. Each gauge 16 may comprise a piezoelectric sensor. It may be a resistive gauge. The gauge may be multiaxial.

[0098] Figures 2, 3 and 6 to 9 show different examples of positioning of the gauges 16 on the casing 8.

[0099] Machine of figures 1 and 2

[0100] Thus, with reference to figures 1 and 2, the positioning of the gauges 16 on the left rear wheel 4 visible in figure 1 is as follows:

[0101] - at least two gauges 16 are located in a radial vertical plane yz occupied by an axis of rotation YY of the machine, the gauges being located on either side of the axis, therefore one above the axis, the other below; and - at least two other gauges 16 are located in a radial horizontal plane xy occupied by the axis YY, these gauges being located on either side of the axis, therefore one at the front of the axis, the other at the rear of the axis. The axis YY forms the intersection of these two planes.

[0102] In this embodiment, as illustrated in Figure 2, three gauges 16 are located in the radial vertical plane and are on the same side of the axis.

[0103] One 16 of the gauges is fixed directly to a flange 18 for fixing the casing 8 to an element external to the machine, in this case to the chassis 3 of the machine. This flange is formed here by ears of the casing.

[0104] Another 16 of the gauges is located at the right of a bearing 20 of the machine with reference to the YY axis. We observe that we are here in the presence of a machine with two bearings 20 located in this example at two respective axial ends of the casing.

[0105] Another 16 of the gauges is located at an area between the other bearing 20 and the fixing flange 18.

[0106] It is advantageous if the machine includes three other gauges symmetrical to these with respect to the YY axis, therefore under the latter.

[0107] The machine comprises a shaft 36 which has a flange 50 in the form of a plate for the rigid connection of the shaft to the wheel 4. Generally speaking, the output shaft has a drive element at its outer end, a flange or keyed or splined drive shaft, for driving a rotating object.

[0108] In this example, there are eight 16 gauges. The number and arrangement of the gauges can vary from one wheel to another.

[0109] In this example, each gauge 16 is glued to the casing as illustrated in Figure 10. The gauges 16 are rigidly and directly fixed to the external face 12 of the casing and arranged to detect a stress on this face and / or a variation in its shape. This deformation is proportional to the intensity of the stress.

[0110] Each gauge 16 is, for example, a piezoelectric gauge. It delivers a voltage representing the stress it is subjected to. Alternatively, a strain gauge such as a resistive gauge can be used. Strain or strain gauges have an electrical resistance that increases with the deformation they are subjected to. Alternatively, multiaxial gauges, such as rosettes, can be used.

[0111] For example, you can use gauges or sensors supplied by the companies HBK or KYOWÀ.

[0112] Alternatively, the invention can be implemented by means of gauges deposited on a support strip, for example made of polymer, which strip is then fixed to the casing on its external face. The strip can, for example, have a cylindrical configuration on a cylindrical portion of the casing. For example, the sensor printing technology marketed by the company Àrc en ciel could be used.

[0113] In each case, all the gauges are connected to an electronic circuit configured to receive the gauge signals and perform the calculations presented below. These arrangements each make it possible to obtain the measurements for implementing the various functions presented in this method of implementing the method. These detections and determinations are made by automated calculation means receiving the gauge signals and processing them in real time by means of suitable programming.

[0114] Machine of figure 3

[0115] In the embodiment of Figure 3, four gauges 16 are located in a radial plane, in this case vertical, occupied by the axis of rotation YY and are on the same upper side of the axis.

[0116] Two of the gauges 16 are fixed directly to the fixing flange 18, on external faces thereof opposite each other.

[0117] Another 16 of the gauges is located at the right of a bearing 20 of the machine with reference to the YY axis. Here we are in the presence of a machine with two bearings 20 located in this example at the same axial end of the casing 8 closest to the wheel 4. This gauge is located here at the right of the bearing 20 closest to the wheel.

[0118] Another of the 16 gauges is located at the right of an area between the two landings

[0119] 20. It is advantageous for the machine to include other gauges symmetrical to these with respect to the YY axis, therefore under the latter.

[0120] Process

[0121] In Figure 1, P represents the stress constituted by the weight of the machine. A fraction of this stress is transmitted by each machine 6 to the wheel 4 concerned. R represents the reaction of the ground on the wheel 4, transmitted from the wheel to the machine, directed upwards.

[0122] In a static situation, that is to say when stationary, the machine 6 thus carries a fraction of the weight P of the machine and undergoes the reaction R of the ground. In a dynamic situation, when the machine 2 is in use and for example when the machine 6 is moving, the machine 6 also receives forces along each of the three axes x, y and z (axial and radial forces with reference to the YY axis) as well as torques exerted around the x and z axes, knowing that the bearings 20 normally prevent the transmission of a torque around the y axis. It can therefore be seen that the machine 6, in addition to constituting a motor, ensures the support of a part of the machine 2 and the absorption of various stresses. All these stresses, forces and torques are transmitted to the casing 8 via the flanges 18, 50 for fixing the wheel and the chassis to the machine.

[0123] Figure 4 illustrates in rear view of the machine the application of lateral forces in the direction y forming a bending torque M around the axis x on the casing. These forces appear in the wheel 4 which they tend to pivot around the axis x, and are transmitted by the shaft 36 of the machine to the casing and the chassis. In the upper part of the casing, the wall therefore undergoes stretching forces E and in the lower part compression forces C. These forces are detected by the gauges 16 located in the vertical plane radial to the axis YY.

[0124] A similar situation is illustrated in Figure 5 but this time on sloping terrain. In other words, the vehicle is inclined along the YY axis, to the left. This time, the bending torque M is supplemented by axial forces A along the shaft 36 which result in compressive forces in the wall 11 of the casing, above the YY axis and below, these forces being more intense below than above. Again, they are detected by the gauges 16. In the present embodiment of the method of the invention, by means of each gauge 16, a stress applied to the casing at a distance from the gauge and / or a variation in a shape of the casing is detected at least once on the casing 8. In the aforementioned examples, the gauge(s) 16 located in the vertical plane radial to the YY axis make it possible to know the static load corresponding to the weight of the machine as well as the vertical forces transmitted.The gauge(s) located in another plane radial to the YY axis, in particular a horizontal plane, make it possible to see other forces.

[0125] During the first detection stage, the machine is stopped, which allows calibration of the measurements to be carried out.

[0126] Then, during the subsequent detection steps, the machine is in operation or even running.

[0127] In this mode of implementation:

[0128] - the amplitudes of the stresses or deformations are measured in respective predetermined zones of the casing, where the gauges are located; and

[0129] - the intensity of one or more forces or one or more torques exerted on the machine from outside the machine is determined by means of the amplitudes.

[0130] Then, each machine is controlled according to these intensities.

[0131] More precisely, for the control of the machine in figure 1:

[0132] - the wheels 4 are controlled individually from each other and

[0133] - each wheel 4 is controlled according to at least one intensity of an effort or torque exerted on the wheel.

[0134] The machine 2 comprises automated processing means capable of implementing this command by taking into account the signals sent by the gauges 16. These signals are transmitted by wired or wireless transmission means.

[0135] Advantageously, the signals from the gauges 16 are first calibrated on a test bench during which the values ​​provided by the gauges are measured in the presence of predetermined stresses. To do this, calibrated forces are exerted by means of two jacks on the machine 6 placed on a calibration bench. This assembly makes it possible to apply forces identical to those generated during its use to the machine. The machine may be stationary or in operation. The signals provided by the gauges 16 are then acquired. This makes it possible to obtain a law or a correspondence table giving the forces as a function of the signals from the gauges. Then, on the machine 6 in operation, in particular rolling, that is to say in use, a stress or deformation value is collected by the gauges, the table is consulted, and the intensity of the corresponding stress is obtained.

[0136] The process makes it possible to identify the wheels that are more or less loaded and to manage traction (particularly in traction control mode). It makes it possible to know the engine's load status and to record its load history. Knowing its endurance, we can determine its aging, that is to say its wear. We can determine the loads seen by the engine and estimate its lifespan to manage its maintenance.

[0137] Machine of figure 6

[0138] In the embodiment of Figure 6, the machine comprises three gauges 16 forming a triangle as seen from one end of the shaft 36 of the machine, as in the figure, the shaft being in the triangle. The three gauges 16 are preferably in the same vertical plane perpendicular to the axis YY.

[0139] This arrangement of the gauges also allows a vector recomposition of the forces seen by the gauges in order to determine their direction and intensity.

[0140] Machine of figure 7

[0141] Figure 7 shows in more detail an exemplary embodiment of a hydraulic machine 6 according to the invention with its main components. Its characteristics are applicable to the previous embodiments. The same applies to the following ones,

[0142] The machine 6 comprises a casing 8 in two parts 30, 32 fixed to each other by members 34 such as screws. It comprises a shaft 36 whose longitudinal axis forms the axis YY. The machine is generally revolutionally symmetrical around this axis. Bearings 20 serve to support the shaft mounted to rotate in the casing 8. The bearings 20 are for example two in number and comprise cylindrical or frustoconical bearings. The two bearings 20 are in this case in direct support against the part 32 of the casing. The machine comprises a cylinder block 38 having housings 40 radial to the axis, the cylinder block being integral in rotation with the shaft 36. Pistons 42 are received in the respective housings and mounted to slide radial to the axis in these housings.

[0143] The machine comprises a cam 44 rigidly fixed to the casing 8 and which has an internal face forming a rolling track for rollers connected to the respective pistons 42. The pistons bear on the cam 44 by means of the rollers. The track has lobes whose alternation around the axis corresponds to a back-and-forth movement of the pistons during the rotation of the shaft 36 relative to the casing 8.

[0144] The machine comprises a distributor 46 capable of putting the housings 10 of the pistons in communication with a high-pressure fluid circuit and with a low-pressure fluid circuit. Depending on the control applied to it, the machine can operate in traction or in retention, that is to say provide a positive or negative rotational torque, and this in one or the other of the two possible directions of rotation.

[0145] A more detailed description of these machine elements can be found in application FR-2 796 886.

[0146] The casing 8 is fixed to the chassis 3 by its flange 18 and the shaft 36 is fixed to the wheel 4 by its own flange 50. The upper and lower parts of the figure show two different respective configurations of the flange 18 of the chassis, respectively connected directly to the part 30 of the casing furthest from the wheel and to its part 32 closest to the wheel.

[0147] The machine comprises above the YY axis two gauges 16, one of which is located at the bearing 20 closest to the flange 50 of the shaft and the other is located at the area between the two bearings 20. It preferably comprises two other gauges symmetrical to the previous ones with respect to the YY axis. The four gauges are in the same radial vertical plane.

[0148] Since the machine casing is generally rotationally symmetrical, but skew, it is a priori difficult to place gauges therein that are carried by a flexible ribbon-shaped support. They naturally have a flat shape, and they can also be given an arc-shaped flexion in one direction. To remedy this, as illustrated in the upper part of Figure 7, at least some of the gauges 16 extend against a facet 13 of plane or cylindrical shape. The facet 13 is located in a face of the casing 8 having a shape other than a plane or cylindrical shape, for example conical. Thus, to easily receive these gauges, locations forming a plane or a cylinder surface are machined. The skew or conical surfaces of the casing are arranged in this way to create the desired gauge locations. The other machines shown can also receive these arrangements. The gauges can form a ribbon.

[0149] Figure 8 machine

[0150] In this example and the following one, only the differences between the example considered and that of figure 7 are presented.

[0151] The machine comprises discs forming a brake 52 of the shaft 36 against its rotation relative to the casing. The two bearings 20 are located in this case on either side of the brake 52.

[0152] The machine comprises above the axis two gauges 16, one of which is located at the bearing 20 closest to the flange 50 of the shaft and the other is located at the bearing 20 furthest from the flange 50 of the shaft. It preferably comprises two other gauges symmetrical to the previous ones with respect to the axis YY.

[0153] Machine of figure 9

[0154] In the embodiment of Figure 9, the machine comprises a single bearing 20, formed by a ball bearing in the present example.

[0155] The machine comprises above the axis a gauge 16 located at the right of the bearing 20. It preferably comprises another gauge symmetrical to the first with respect to the Y-Y axis.

[0156] Machine of figures 11 and 12

[0157] In this embodiment of the invention illustrated in figures 11 and 12, the machine has the characteristics of the previous modes except for the following.

[0158] It comprises, as already mentioned, one or more gauges 16 fixed to the flange 18 of the casing. These may be the only gauges. Figure 11 illustrates a section of the casing with the main part of the flange 18, formed for example from metal.

[0159] As illustrated, the gauge or at least one of the gauges 16 extends against a circumferential face 54 of the flange. This is a cylindrical face. In this case, the face 54 is oriented in the opposite direction to the axis of rotation YY of the machine. It is provided here that the circumferential face 54 extends back from an external circumferential edge 56 of the flange. This edge 56 has a circular shape here.

[0160] The flange 18 comprises at least one support 58 such as a plate extending in projection, along the axis of rotation, from a flat axial face 60 of the flange 18 perpendicular to this axis. In this case, there are two supports 58. Each support 58 has the circumferential face 54. Each of these circumferential faces 54 carries one or more gauges 15, here two on each circumferential face.

[0161] Each support 58 extends over only a fraction of a circumference of the flange 18 so as to provide clearances 62 between the supports on the axial face 60 of the flange. Each support 58 is, for example, crescent-shaped. Overall, the supports correspond to the placement of the screws for fixing the engine to the chassis. Each of the two clearances 62 comprises one or more electronic components 64 connected to the gauge or gauges 16. These components may be power supplies, amplifiers, transmitters, or a circuit for shaping the signal of the gauges.

[0162] We find that two of the 16 gauges are located in the vertical plane yz occupied by the axis of rotation YY, on either side of the axis and two others in the horizontal plane xy occupied by this axis, on either side of the axis. The two planes xy, yz are intersecting. All the 16 gauges are located here in the same plane xz perpendicular to the axis of rotation.

[0163] As illustrated in Figure 12, the flange 18 comprises a protective member 66, such as a covering or a hood, covering the gauge(s) 16 and / or the clearance(s) 62. This may be an overmolding. The protective member 66 here covers the axial faces 60 of the flange but not those of the supports 58.

[0164] An electrical connection 70, 72 is provided on the hood 66, for connection to a vehicle wiring harness. Alternatively, a contactless connection may be provided, for example by radio link. The electrical connection may be a socket flush with the hood, or it may be a length of electrical cable(s) 70 emerging from the hood and carrying a connector 72 at one end for connection to the vehicle wiring harness.

[0165] It is preferable that the holes 68 for fixing the flange 18 or collar to the machine 2 are smooth (not tapped) and do not contact the fixing members such as the bolts which pass through them. It is also preferable that the flange 18 is gripped between these members (in particular the bolt heads (and washers)) and the chassis of the machine. It is desirable in fact that the flange 18 is only stressed in compression for a good measurement. Depending on the forces applied, the fixing members such as the bolts are stretched under tension (the engine is held on the chassis by adhesion, under pressure on the chassis) and will then lengthen more or less. The measuring wedge zone will therefore be more or less in compression. At time zero after assembly, the instrumented flange is therefore under a certain initial compressive stress due to the bolting.)

[0166] For example, by distributing four 16 gauges (located for example at the top, bottom, right and left of the axis, or at 0, 3, 6 and 9 o'clock), the forces can be measured along a vertical axis and a horizontal axis.

[0167] The same arrangement of gauges can be provided on machine ears, this is the situation in which the flange has a non-circular shape and includes two protruding parts forming ears for fixing.

[0168] Many modifications can be made to the invention without departing from its scope. The number and arrangement of the gauges can be varied. A reduced number of gauges can be provided on the machine, for example two or even just one.

Claims

Claims 1. Rotating machine (6) comprising: - a casing (8), and - at least one gauge (16) directly fixed to the casing and arranged to detect a stress applied to the casing at a distance from the gauge and / or a variation in a shape of the casing.

2. Machine according to the preceding claim, the machine (6) being hydraulic.

3. Machine according to at least one of the preceding claims wherein the gauge or at least one of the gauges (16) comprises a piezoelectric sensor.

4. Machine according to at least one of the preceding claims wherein the gauge or at least one of the gauges (16) is a resistive gauge.

5. Machine according to at least one of the preceding claims wherein the gauge or at least one of the gauges (16) is a multi-axial gauge.

6. Machine according to at least one of the preceding claims in which the gauge or at least one of the gauges (16) is located in a vertical plane (yz) occupied by an axis (YY) of rotation of the machine.

7. Machine according to at least one of the preceding claims in which the gauge or at least one of the gauges (16) is located in a horizontal plane (xy) occupied by an axis (YY) of rotation of the machine.

8. Machine according to at least one of the preceding claims which comprises two gauges (16) located in a plane (xy, yz) occupied by an axis (YY) of rotation of the machine, the gauges being located on either side of the axis.

9. Machine according to the preceding claim in which the plane (yz) is vertical.

10. Machine according to the preceding claim 8 in which the plane (xy) is horizontal.

11. Machine according to at least one of the preceding claims which comprises: - two gauges (16) located in a first plane (xy) occupied by an axis of rotation of the machine, the gauges being located on either side of the axis; and - two gauges (16) located in a second plane (yz) occupied by the axis, the gauges of the second plane being located on either side of the axis; the two planes (xy, yz) being intersecting.

12. Machine according to at least one of the preceding claims which comprises at least two gauges (16) extending in the same plane (xz) perpendicular to an axis (Y-Y) of the machine.

13. Machine according to at least one of the preceding claims which comprises three gauges (16) forming a triangle as seen from one end of a shaft (36) of the machine, the shaft being located in the triangle.

14. Machine according to at least one of the preceding claims in which the gauge or at least one of the gauges (16) is fixed directly to a flange (18) for fixing the machine to an element (3) external to the machine.

15. Machine according to the preceding claim in which the gauge or at least one of the gauges (16) extends against a circumferential face (54) of the flange (18) oriented in the direction opposite to an axis of rotation (YY) of the machine or in the direction of the axis of rotation.

16. Machine according to the preceding claim in which the face (54) extends back from an external circumferential edge (56) of the flange (18).

17. Machine according to at least one of claims 15 or 16 wherein the flange (18) comprises at least one support (58) extending projecting from an axial face (60) of the flange perpendicular to the axis of rotation (YY), the support (58) having the circumferential face (54) and extending over only a fraction of a circumference of the flange so as to provide on the axial face (60) of the flange one or more clearances (62) in a circumferential extension of the support, the or each clearance (62) comprising one or more electronic components (64) connected to the gauge or gauges (16).

18. Machine according to at least one of claims 15 to 17 wherein the flange (18) comprises a protective member (66), such as a covering or a hood, covering the gauge(s) (16) and / or the clearance(s) (62).

19. Machine according to at least one of the preceding claims in which the gauge or at least one of the gauges (16) is located at right angles to a bearing (20) of the machine.

20. Machine according to at least one of the preceding claims in which the gauge or at least one of the gauges (16) is located at right angles to an area situated between a bearing (20) of the machine and a flange (18) for fixing the machine to an element (3) external to the machine.

21. Machine according to at least one of the preceding claims in which the gauge or at least one of the gauges (16) is located on an external face (12) of the casing (8).

22. Machine according to at least one of the preceding claims in which the gauge or at least one of the gauges (16) extends against a facet (13) of plane or cylindrical shape, the facet being located in a face of the casing (8) having a shape other than a plane or cylindrical shape, the gauge forming in particular a ribbon.

23. Machine according to at least one of the preceding claims, which comprises: - an annular-shaped cam having lobes on one face, in particular the internal face, of the cam, and - pistons extending opposite the lobes.

24. Device (2) comprising: - a main part (3) and - a member (4) mounted to move relative to the main part by means of a machine (6) according to any one of the preceding claims.

25. Machine (2) comprising a chassis (3) and wheels (4), at least one of the wheels being connected to the chassis by a machine (6) according to any one of the claims 26. Method in which a stress applied to the casing at a distance from a detection zone and / or a variation in a shape of the casing is detected at least once on a casing (8) of a rotating machine (6).

27. Method according to the preceding claim in which the machine (6) is stopped during the detection step or one of the detection steps.

28. Method according to at least one of claims 26 to 27 wherein the machine (6) rotates during the detection step or one of the detection steps.

29. Method according to at least one of claims 26 to 28 in which: - amplitudes of at least two stresses or two deformations are measured in two respective predetermined zones of the casing (8); and - at least one intensity of a force or torque exerted on the machine (6) from outside the machine is determined by means of the amplitudes.

30. Method according to at least one of claims 26 to 29, in which the machine (6) is controlled as a function of the intensity or the torque.

31. Method for controlling a machine (2) comprising two rotating machines (6) connecting wheels (4) to a chassis (3) of the machine, in which: - the wheels are controlled individually from each other and - each wheel is controlled by means of a method according to the preceding claim as a function of at least one intensity of a force or torque exerted on the wheel.

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