Coupling for a hydraulic machine comprising a flow meter

Abstract

The invention relates to a device (7) comprising: - a pipe (10) having an inner face (12) extending along an axis (X-X); - a flow meter (14) defining a direction of measurement (D) in the pipe, wherein the direction is inclined with respect to the axis and intercepts the inner face, and wherein the flow meter defines a measurement zone in the pipe; and - at least one sensor (22, 24) distinct from the flow meter, wherein the sensor extends outside the measurement zone or in a plane (P1, P2) that is perpendicular to the axis and passes through the flow meter.

Description

[0001] HYDRAULIC MACHINE CONNECTION INCLUDING A FLOW METER

[0002] FIELD OF THE INVENTION

[0003] The invention relates to rotating hydraulic machines.

[0004] STATE OF THE ART

[0005] Rotating hydraulic machines are known that operate as motors or pumps. For example, this is a hydraulic wheel motor of a machine or vehicle, in which the fixed part includes hydraulic lines and the rotating part includes a cylinder block with pistons and is connected to an output shaft receiving a wheel. The pistons are supported against a corrugated cam carried by the fixed part. Pressurizing the machine allows the pistons to move on the cam, which sets the wheel in rotation. The machine has a casing including a flange for attachment to the chassis of the machine.

[0006] When such a machine breaks down, it results in the temporary immobilization of the machine or vehicle for repair or replacement, which generates immobilization costs, in addition to the repair or replacement costs.

[0007] One aim of the invention is to better understand the health status of the machine and to facilitate its predictive maintenance in order to be able to detect in advance when such a machine will require servicing or preventive maintenance.

[0008] STATEMENT OF THE INVENTION

[0009] To this end, the invention provides a device comprising:

[0010] - a conduit having an internal face extending along an axis;

[0011] - a flow meter defining a measurement direction in the conduit, the direction being inclined relative to the axis and intercepting the internal face, the flow meter delimiting a measurement zone in the conduit; and

[0012] - at least one sensor (separate from the flow meter, the sensor extending outside the measurement zone or in a plane perpendicular to the axis and passing through the flow meter.

[0013] Thus, the flow meter makes it possible to know an instantaneous value of the fluid flow in the pipe in communication with the hydraulic machine. The sensor gives another quantity in the same pipe and at the same time. The joint knowledge of these two quantities makes it possible, if necessary, to detect a drop in machine performance or an operating anomaly, and if necessary to plan a maintenance operation. Positioning the sensor outside the zone or at the edge of it makes it possible to avoid generating turbulence in the portion of the pipe used for flow measurement, so that it is more precise. The flow measurement also makes it possible to determine the volumetric efficiency if the inlet flow rate upstream of the measurement point is known (from the speed). Thanks to this data, it is possible to search for the best efficiency point of the machine, and, if it forms an engine, particularly for a vehicle, to improve its traction.

[0014] The invention makes it possible to obtain information on the characteristics of the flow of fluid, in particular of pressurized fluid, in hydraulic pipes by means of a compact, reliable arrangement that is easy to insert into the circuit of a machine or device.

[0015] According to the invention, an installation is also provided comprising:

[0016] - a hydraulic machine,

[0017] - a device, and

[0018] - at least one hydraulic fluid circuit configured to put the device in communication with the machine, the device comprising:

[0019] - a hydraulic fluid conduit having an internal face extending along an axis;

[0020] - a flow meter defining a measurement direction in the conduit, the direction being inclined relative to the axis and intercepting the internal face, the flow meter delimiting a measurement zone in the conduit; and

[0021] - at least one sensor separate from the flow meter, the sensor extending outside the measurement zone or in a plane perpendicular to the axis and passing through the flow meter.

[0022] The flow meter can be predicted to be an ultrasonic flow meter.

[0023] The conduit can be made of a material permeable to ultrasound, for example PEEK.

[0024] The flow meter can be predicted to be a travel time flow meter.

[0025] The device may further have at least one of the following characteristics: - the flow meter comprises a first transceiver and a second transceiver, the first transceiver and the second transceiver being aligned along the direction, the sensor extending outside the measurement zone or in a plane perpendicular to the axis and passing through one of the first transceiver and the second transceiver;

[0026] - the first transceiver has a transmission-reception axis coinciding with the direction and the second transceiver has a transmission-reception axis coinciding with the direction; and

[0027] - the first transceiver has a transmission-reception axis and the second transceiver has a transmission-reception axis, at least one of the two transmission-reception axes being non-coincident with the direction.

[0028] It can also be predicted that the flow meter is Doppler effect.

[0029] The direction can be expected to form an angle with the axis between 20 and 70°.

[0030] An installation is also planned including:

[0031] - a hydraulic machine,

[0032] - a device according to the invention, and

[0033] - at least one fluid circuit configured to put the device in communication with the machine.

[0034] The circuit can be provided with a drain.

[0035] At least one of the following characteristics can be expected:

[0036] - the device has a total dimension measured along the axis of the conduit less than or equal to 120% of a dimension of the measurement zone measured along the axis of the conduit;

[0037] - the device has a total dimension measured along the axis of the conduit less than or equal to 10.33 times a largest dimension of the conduit in the measurement zone measured along a direction perpendicular to the axis of the conduit;

[0038] - the device has a total dimension measured along the axis of the conduit less than or equal to 4 times a largest dimension of the device in a plane perpendicular to the axis of the conduit;

[0039] - the measurement zone has a length l less than or equal to 3.2 times a largest dimension of the conduit in the measurement zone measured in a direction perpendicular to the axis of the conduit;

[0040] - the axis of the conduit extends in a plane perpendicular to an axis of rotation of the machine; - the device has a total dimension measured along the axis of the conduit less than or equal to a largest dimension of the machine measured in a plane perpendicular to the axis of rotation of the machine;

[0041] - the axis of the conduit is parallel to an axis of rotation of the machine; and

[0042] - the device has a total dimension measured along the axis of the conduit less than or equal to a largest dimension of the machine measured along the axis of rotation of the machine.

[0043] A process is also provided in which:

[0044] - a fluid flow rate is determined in an area of ​​a conduit communicating with a hydraulic machine, and

[0045] - at least one quantity is measured from a fluid temperature and a fluid pressure in the conduit upstream or downstream of the zone.

[0046] In the process, it can be provided that the machine operates as a pump or as a motor.

[0047] The method may be controlled by automated means associated with a program comprising code instructions controlling the implementation of the method when executed on such means.

[0048] These means can be programmed to send an alert message when one of the quantities measured by the device exceeds a predetermined threshold, indicating an anomaly.

[0049] DESCRIPTION OF FIGURES

[0050] We will now describe embodiments of the invention with the support of the appended figures given as non-limiting examples and in which:

[0051] - figure 1 is a diagram of an installation according to an embodiment of the invention comprising a device according to the invention and a hydraulic machine;

[0052] - Figure 2 is a cross-sectional view of the device of Figure 1;

[0053] - figure 3, figure 4 and figure 5 are diagrams similar to figure 1 showing alternative embodiments of the device;

[0054] - Figure 6 illustrates a more detailed arrangement of the device of Figure 1;

[0055] - Figure 7 is a sectional view of an example of a rotating hydraulic machine forming part of the invention; - Figure 8 is a view similar to Figure 1 illustrating a second embodiment;

[0056] - figures 9 and 10 are views of hydraulic circuits respectively of closed and open type showing different possible locations of the device of the invention; and

[0057] - figures 11 to 21 illustrate hydraulic machines with several examples of location of the device equipped with the flow meter.

[0058] DETAILED DESCRIPTION OF THE INVENTION

[0059] First embodiment

[0060] Figures 1 and 2 illustrate an installation 2 according to a first embodiment of the invention. The installation 2 comprises:

[0061] - a rotating hydraulic machine 6,

[0062] - a device 7 according to a first embodiment of the invention, and

[0063] - at least one fluid circuit 9 configured to put the device 7 in communication with the machine.

[0064] We will first describe device 7.

[0065] It comprises a conduit 10 having an internal face 12 extending along an axis X-X. The conduit thus forms a tubular body or sleeve open at its two axial ends. When the device 7 is in operation, the internal face 12 therefore forms a fluid vein in communication with the machine 6.

[0066] In this example, the inner face 12 has a cylindrical shape. In particular, it has here a profile having a cross-section which has a length greater than a width of the section, as illustrated in Figure 2. This makes it possible to give the fluid a more homogeneous speed in a large part of the section. The section here has a rectangular shape, as illustrated in the same figure. But the section can be given a different shape, for example circular, oval or elliptical.

[0067] The device 7 also comprises an ultrasonic flow meter 14. In this example, the flow meter 14 is a flow meter measuring the travel time or transit time. It comprises in this case a first transmitter-receiver 16 and a second transmitter-receiver 18, these two elements being aligned in a direction D inclined relative to the axis XX. The direction forms an angle with the axis of between 20 and 70°. It can be between 30 and 40° and is for example 45°. Each of the transmitter-receivers forms an ultrasonic transducer.

[0068] The respective axial positions of the two transceivers delimit a measurement zone 21 in the conduit 10. The axis XX extends between the transceivers so that the latter are located on either side of the axis. With reference to the direction 34 of flow of the fluid in the conduit, the transceiver 16 is located downstream of the transceiver 18.

[0069] In operation, the downstream transceiver 16 sends an acoustic wave to the upstream transceiver 18, and automated means measure the travel time of this wave. In a second step, the upstream transceiver 18 sends an acoustic wave to the downstream transceiver 16, and the corresponding second travel time is measured. The difference in duration between the two paths of the wave makes it possible to obtain the speed of the fluid. By knowing the area of ​​the cross-section of the conduit, the flow rate of the fluid is deduced by the automated calculation means.

[0070] In this example, the two transceivers 16, 18 do not open into the conduit 10.

[0071] The measuring zone 21 corresponds to the longitudinal section of the conduit 10 crossed by the ultrasonic waves.

[0072] The downstream transmitter-receiver 16 has a transmission-reception axis VV and the upstream transmitter-receiver 18 has a transmission-reception axis MM, at least one of these two axes being non-coincident with the direction D, preferably the two axes being non-coincident, as illustrated in FIG. 1. This arrangement makes it possible to compensate for the deflection of the sound waves which occurs by refraction during the change of medium at the outlet of each transmitter-receiver towards the fluid in the conduit. In this case, the tubular body is made of a material permeable to ultrasound, for example PEEK.

[0073] Alternatively, it can be provided that the axes VV and MM coincide with the direction D and are therefore merged with it, in particular when the transmitters-receivers are mounted opening into the conduit 10.

[0074] The device 7 also comprises at least one sensor distinct from the flow meter 14. In this case, it comprises two sensors distinct from the flow meter, namely in this example a temperature sensor 22 and a pressure sensor 24. In this case, each of these sensors 22, 24 extends in a plane perpendicular to the axis XX and passing through one of the transmitter-receiver 16 and the transmitter-receiver 18. Thus, one of the sensors, in particular the pressure sensor 24, extends in a plane P1 passing through the transmitter-receiver 16 and the other sensor, in particular the temperature sensor 22, extends in a plane P2 passing through the transmitter-receiver 18, as illustrated in FIG. 1. In fact, the inclination of direction D relative to axis XX provides two zones located at the right of the two transmitter-receivers respectively, zones which allow one or more sensors to be housed without them disturbing the operation of the flow meter 14. In addition, a particularly compact device 7 is thus obtained.Each of the sensors extends outside the measuring area 21. This prevents any disturbance of the flow at the location of the flow measurement.

[0075] The conduit 10 thus forms a measuring chamber.

[0076] The figures do not represent the exact scale, dimensions or proportions of the elements illustrated.

[0077] According to the variant of Figure 3, the temperature sensor 22 and the pressure sensor 24 are combined in an element 26 mounted in the wall of the conduit 10. One of the sensors, here the sensor 22, extends in the plane P1 and the other, here the sensor 24, extends downstream of the latter.

[0078] Generally, it is expected that the temperature 22 and pressure 24 sensors are placed as close as possible to the fluid stream.

[0079] According to the variant of Figure 4, the sensor or at least one of the sensors 22, 24 is placed in a housing 28 formed in the wall of the conduit 10 and which opens into the internal face 12 and therefore into the fluid stream. In this way, the sensors are placed in through wells formed in the material of the body of the device 7, so that their end connects smoothly with the internal face of the conduit.

[0080] In a variant, they may be slightly set back from this face and form an offset. This offset may create slight turbulence in the fluid, but if the sensors are placed in the indicated areas, this does not affect the velocity measurement. The remaining space, generated by this setback, may however be filled with glued or molded material to preserve a smooth surface in the fluid stream. In accordance with the variant of Figure 5, the housing 28 is separated from the inner face 12 by a wall 31. Thus, the two sensors 22 and 24 may be placed in non-opening wells in the material of the conduit 10, as also shown in Figure 1. An optional feature is also found in the arrangement of Figure 3. This leaves a thin wall 31 between the fluid and the sensors 22, 24. This wall is thin and flexible enough to transmit the fluid pressure to the pressure sensor 24.It is also thin enough and thermally conductive enough to transmit the fluid temperature to the temperature sensor 22. The advantage of using non-through wells is that it ensures a good seal for the sensor mounting and provides a smooth area for the fluid stream.

[0081] The sensors 22, 24 can be screwed into the material of the body of the device 7, inserting a seal if necessary. They can also be glued. Alternatively, if the body of the device 7 is obtained by molding plastic material, they can be overmolded in it.

[0082] With particular reference to the temperature sensor 22, an interface 25 made of heat-conducting material, for example copper, may be interposed between the temperature sensor and the fluid, as illustrated in FIG. 1. This interface may be overmolded or inserted in a sealed manner into the body of the device 17, which makes it possible to remove or replace the temperature sensor 22 easily, without having to worry about sealing with a pressurized fluid.

[0083] The flow meter 14 and the sensors 22, 24 may be commercial sensors.

[0084] A more detailed arrangement of the device 7 of Figure 1 is illustrated in Figure 6.

[0085] An example of the embodiment of the machine 6 is illustrated in Figure 7. Other machine configurations are possible.

[0086] The machine 6 comprises a casing 8 in two parts 30, 32 fixed to each other by members 35 such as screws. It comprises a shaft 36 having a longitudinal axis YY. The machine is generally revolutionally symmetrical about this axis. Bearings 20 serve to support the shaft 36 mounted to rotate in the casing 8. They 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. Alternatively, the machine 6 comprises a single bearing 20. The machine 6 forms for example a wheel motor, that is to say that it combines the functions of motor and bearing, so as to produce a half-axle which carries the weight of a vehicle or machine. Such a machine 6 is intended to be placed in a wheel, and is very exposed to friction from objects, and to tearing.

[0087] 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 40 and mounted to slide radially to the axis in these housings.

[0088] The machine comprises a cam 44 rigidly fixed to the casing 8 by being interposed between parts 30 and 32 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.

[0089] The machine comprises a distributor 46 capable of putting the housings 40 of the pistons in communication with a high-pressure fluid circuit and with a low-pressure fluid circuit. The distributor is connected by conduits to the fixed part of the machine, so as to be connected to the hydraulic fluid network of the machine or installation. In general, a rotating hydraulic machine comprises at least one supply port and one discharge port, that is to say an inlet port and an outlet port, designated A and B. In the event of a change in the direction of rotation by reversing the flow rates, the direction of the flow rates is reversed in the ports A and B. The hydraulic machine also comprises a drain D intended to collect internal leaks from the mechanism of the hydraulic machine which arrive in the casing 8.Each of these ports includes a means for fixing and connecting hydraulic lines, for example a threaded orifice with sealing surfaces, to be hydraulically connected to a hydraulic line. The casing 8, the cam 44 and the distributor 46 correspond to the fixed part of the machine. The shaft 36, the cylinder block 38 and its pistons and the flange 50 form the rotating part of the hydraulic machine.

[0090] The machine can form a pump or a motor. In motor mode, depending on the command applied to it, it can operate in traction or in restraint mode, i.e. provide a positive or negative rotational torque, and this in one or the other of the two possible directions of rotation. A more detailed description of these elements of the machine can be found in application FR-2 796 886, this document being mentioned here only as an example for such a machine.

[0091] The fluid circuit 9 forms, for example, a drain of the casing of the machine. But the device 7 can be mounted on other hydraulic lines of the machine than the drain, for example on a supply or discharge circuit. The device 7 is fixed, for example, on a hydraulic inlet or outlet of the machine, of a pump supplying the machine, or of a valve, for example by means of a thread for hydraulic piping. The device 7 can also be fixed anywhere in a hydraulic circuit connected to the machine 6, along its drain or its supply or discharge pipes.

[0092] The fluid is a hydraulic fluid for power transmission. Typically, it is an oil resistant to extreme pressures, and of specific viscosity. These oils are defined for example by the ISO6743-4 standard which describes the "H" hydraulic oils used in hydraulic systems. The ISO11158 standard specifically describes mineral fluids and proposes a classification according to their antioxidant, anticorrosive and antiwear properties, which defines the HV, HL, HM, HV, HG oils. For hydraulic power transmissions, activating hydraulic machines, the HV range is often preferred. These fluids can be used for operating pressures ranging from 0 to 600 bar, and in a range of use from 20 to 80°C in operation. (Throughout the application, one bar is worth 10 5Pascal.) The ISO 3448 standard defines a viscosity classification for hydraulic machines. For rotating hydraulic machines, depending on their operating temperature, the viscosity must be between 9 and 500 cSt (centiStokes) during use. Preferably, depending on the temperature of the location and the machine in operation, the ISO VG32 (32 cSt at 40°C), ISOVG46 and ISOVG68 grades are used. The fluid is therefore often referred to as HV32 oil, or HV46 (46 cSt at 40°C), or HV68 (68 cSt at 40°C), going from the most fluid to the most viscous. HV32 oils are recommended for cold environments, HV46 oils are for temperate environments, and HV68 or 100 oils are for hot environments. Generally speaking, hydraulic fluids useful for hydraulic machines are high or extreme pressure oils with a viscosity between 32 and 100 cSt at 40°C.

[0093] As illustrated in Figure 6, the section of the fluid stream in the circuit 9 is for example circular at the inlet of the device 7, the ends of the device being connected to the circuit for example by means of screwed connections, then changes shape in the measuring chamber where it can be crossed by the wave beam of the flow meter 14, then becomes circular again at the outlet. In a preferred manner, the area of ​​the section of the stream remains substantially constant despite these changes in shape.

[0094] The device 7 can itself form a connection.

[0095] This installation 2 makes it possible to implement the method of the invention in an example as follows.

[0096] With the hydraulic machine in operation, a fluid flow rate is measured by means of the flow meter 14 in a zone of the conduit 10 in communication with the machine, in this case in the measurement zone 21. This measurement is carried out as indicated above, which makes it possible to obtain the fluid flow rate.

[0097] Simultaneously or concomitantly, at least one quantity is measured from among a temperature of the fluid and a pressure of the fluid in the conduit 10 upstream or downstream of the zone, by means of the sensors 22 and 24.

[0098] Device 7 allows measurements to be taken at the same location to know and monitor the condition of the machine in real time. Flow and pressure information allows the efficiency of the hydraulic machine to be assessed, and for a motor, the torque it delivers. Temperature information allows the assessment to be refined according to the viscosity of the fluid.

[0099] When the device 7 is in communication with the drain, it allows the leakage flow rate to be monitored, a flow rate which changes depending on the health of the machine. Similarly, monitoring the temperature makes it possible to detect an abnormal increase in temperature and prevent possible damage.

[0100] Generally speaking, flow and temperature information makes it possible to assess the power used in the machine and to monitor changes in oil temperature. This can be used to limit the power required by the driver in the event of abnormal oil heating, so as to keep the oil within its temperature and viscosity range. This can allow excessive power peaks to be allowed as long as the oil is not beyond a certain limit, or to detect abnormal heating for normal power, which would be a sign of reduced efficiency, and therefore deterioration of the machine. Similarly, a flow measurement on a machine drain port, if it detects an abnormal flow, can detect deterioration of the machine. The machine can therefore be protected during use, while using it more intensively.

[0101] It is possible to equip several hydraulic machines of the same circuit with the device of the invention. However, to allow this on a vehicle or machine, the device will preferably be compact and limited in length so that it can be assembled easily, particularly at the level of the engines which are very exposed.

[0102] Second embodiment

[0103] Figure 8 illustrates a second embodiment of the invention.

[0104] The common features with the first mode will not be repeated and we will only present the differences. Similarly, the variants exposed in relation to the first mode are also applicable with this second mode.

[0105] Here, the flow meter 14 is Doppler effect. It is based on a measurement of particle speed by Doppler effect. In particular, this method uses the reflection of a wave by particles. In this example, the flow meter comprises a single transmitter-receiver which emits a wave train at a given frequency. The fluid comprises particles 15 driven in motion with it. Such a particle 15 reflects the wave towards the transmitter-receiver, a wave which is received with a frequency different from the transmission frequency. The frequency difference is representative of the speed of movement of the particle, therefore that of the fluid. Automated calculation means therefore make it possible to determine the flow rate.

[0106] The transceiver transmits the wave train along direction D, here inclined at 45° to the XX axis, which forms an optimal angle with respect to the flow. However, this angle can be located in a range of 20 to 70°. An angle much smaller than 45° creates a significant attenuation of the frequency difference. An angle much larger than 45° creates an attenuation of the amplitude of the received signal as the particle moves away from the flow meter.

[0107] The moving particles may be solid particles present in the hydraulic fluid, such as impurities from the machine or the oil forming the fluid, for example wear particles from the machine or particles from the filter media of the hydraulic circuit. They may also be air bubbles or cavitation. Generally speaking, any heterogeneity in the hydraulic fluid can be detected in this way and used for measuring the flow rate. In this case, the flow meter 14 comprises a single element. The measuring zone 21 is delimited by the axial positions of the points 17 at which the direction D intercepts the internal face 12 of the conduit when entering the vein and leaving it.

[0108] It is observed that the two sensors 22, 24 are outside this zone. Alternatively, at least one of the two sensors could be located in line with the flow meter and / or in line with one of the points 17.

[0109] Integration into a hydraulic circuit

[0110] At each end of the device 7 is provided a means of hydraulic connection to a hydraulic machine or a hydraulic fluid line, for example a length of thread with a seal system, or a flat screw-on flange with a seal system. The fastening system is not detailed, but the length used for this is as close as possible to the measurement area. In this way, the device combining several sensors is very compact and can be placed on a hydraulic fluid line, and in particular directly assembled on one side on a hydraulic machine.It is understood that if the device is placed on a vehicle or machine, for example on the hydraulic machine operating as a motor and driving a wheel, or in the environment under the hood of the primary engine of the machine, it is preferable that the size of the device is as small as possible, in particular that it is compact, and that its length, understood here as its overall length, is limited. Very advantageously, the fact that the length of the device does not exceed 120% of the length of the measurement zone makes it possible to screw the device directly onto the hydraulic machine without protruding too much.

[0111] The conduit 10 and the fluid stream open onto the axial ends of the device and thus define a hydraulic inlet port and a hydraulic outlet port, intended to be connected to a hydraulic object whose characteristics of the fluid in motion are to be measured. These ports are either male fittings or female fittings, for example threaded. They may also be smooth male or female fittings completed by a connecting flange 19 in the form of a collar to create a secure hydraulic connection. Such a flange is shown in two simplified examples in Figure 1. The connection may contain seals.

[0112] The inlet and outlet ports can be connected to hydraulic lines. Advantageously, one of the ports, for example the inlet or outlet port, can be connected directly to the housing of a hydraulic machine, the other port being connected to a hydraulic line of the hydraulic circuit. Alternatively, the inlet or outlet port is connected to the hydraulic machine by a T-bend, so that the body of the device extends along the wall of the housing of the hydraulic machine. For both of these arrangements, especially for a hydraulic machine operating as a motor, it is preferable for the device to be very compact. If the device is compact and does not protrude from the environment of the hydraulic machine, it is possible to use it on a motor driving a wheel, which is very exposed.

[0113] The device therefore constitutes a hydraulic component capable of being placed anywhere in a hydraulic circuit, and in particular in a hydraulic power transmission circuit.

[0114] Machine 6 is typically a hydraulic machine used for power transmission. Typically, a hydraulic machine, pump or motor, receives a pressurized fluid and produces a movement, and vice versa. For example, a hydraulic pump receives a movement through its input shaft, which is defined by a rotational speed and a torque, and produces a fluid flow at a certain flow rate and a certain pressure. A hydraulic motor receives the pressurized fluid, and transforms its flow rate and pressure into rotational speed and torque through its output shaft. In general, these machines are reversible. A hydraulic circuit is composed by assembling hydraulic machines connected by hydraulic conduits. The machines are therefore transmitters or receivers. The hydraulic fluid that runs through the circuit between the machines allows the transmission of movement and power between a transmitter machine and a receiver machine.

[0115] For example, we can consider a hydraulic circuit comprising a pump, driven at the input by its shaft by a primary movement source, for example a thermal or electric motor. This circuit can comprise at least one hydraulic receiver, for example a hydraulic motor or a cylinder which generates a movement, for example for the translation of a machine or a vehicle, for the driving of a tool, or to generate a movement. If it is a hydraulic motor, it receives hydraulic fluid under pressure and provides a movement on its shaft, which can be connected to a wheel to be driven, or any rotational movement, for example to drive machine drums, winches, drills or tunnel boring machines. The hydraulic machine operating as a pump receives on its shaft a power P equal to the torque C multiplied by the rotation speed R:

[0116] P(W) = C(Nm) XR (rad / s)

[0117] The same principle applies to the machine operating as a motor.

[0118] A linear machine of the jack type will develop a power P equal to the thrust N multiplied by the linear speed V:

[0119] P(W) = P(N) XV (m / s)

[0120] For all these machines, up to the efficiency, they receive or deliver the power P in the form of a hydraulic fluid flow Q and a pressure P, such that

[0121] P(kW) = p(Bar)xQ(l / mn) / 600

[0122] In a hydraulic circuit comprising a transmitter, for example a pump, and receivers, for example motors, depending on the efficiency of the components, the hydraulic power emitted by the pump is consumed by the receivers and transported by the hydraulic fluid in the form of flow and pressure. We therefore see that the hydraulic circuit composed of at least one hydraulic machine operating as a pump, and one hydraulic machine operating as a receiver, for example a hydraulic motor, is a power transmission circuit.

[0123] Different locations of the device 7 are indicated as examples on the circuits of Figures 9 and 10.

[0124] The hydraulic circuit 57 illustrated in Figure 9 is of the closed type. It comprises a hydraulic machine 6 forming in this case a motor which turns a wheel 60. It comprises a primary movement source 62 formed for example by an electric or thermal motor. This source actuates a shaft of a hydraulic pump 64 connected to the machine 6 by supply 66 and discharge 68 conduits. The circuit is supplied with fluid by a booster pump 70 pumping fluid from a reservoir 72 to inject it into a branch 74 of the circuit putting the supply 66 and discharge 68 conduits in communication. This branch 74 is also equipped with two non-return valves 76 interposed between the booster pump 70 and the supply 66 and discharge 68 conduits respectively. The two valves 76, also called filling valves, pass only in the direction of the discharge conduit 68.The hydraulic pump 64 is equipped with a drain 80 communicating with the reservoir 72. Similarly, the machine 6 is equipped with a drain 82 communicating with the reservoir 72.

[0125] Different possible locations of the device 7 have been illustrated in Figure 9. It is possible to provide a single device 7 at one of these locations. It is also possible to provide several devices 7 at different locations in the circuit 57. Possible locations of the device 7 are as follows:

[0126] - on the discharge pipe 68 at the level of the pump 64, at the level of the machine 6 or at a distance from both;

[0127] - on the supply pipe 66 at the level of the pump 64, at the level of the machine 6 or at a distance from both;

[0128] - on drain 80 at the level of pump 64 or at a distance from it; and

[0129] - on drain 82 at machine 6 or at a distance from it.

[0130] The hydraulic circuit 58 illustrated in Figure 10 is of the open type. We will only focus in the following on the differences with the circuit of Figure 9. As in the circuit of Figure 9, we find the hydraulic machine 6, the primary movement source 62, the hydraulic pump 64, the supply ducts 66 and discharge ducts 68, the reservoir 72 and the drains 80 and 82

[0131] However, the feed pump and the associated branch are absent. The pump 64 is supplied with fluid directly from the reservoir 72 via a pump conduit 65. It supplies fluid to the machine via the supply conduit 66. The discharge conduit 68 connects the machine 6 directly with the reservoir 72.

[0132] This time, possible locations of Device 7 are as follows:

[0133] - on the discharge pipe 68 at the level of machine 6 or remotely;

[0134] - on the supply pipe 66 at the level of the pump 64, at the level of the machine 6 or at a distance from both;

[0135] - on drain 80 at the level of pump 64 or at a distance from it; and

[0136] - on drain 82 at machine 6 or at a distance from it.

[0137] In the machine of Figure 7, which can operate in both types of circuit, the supply and discharge conduits can be connected to ports A and B as desired. As an example, the device 7 fixed to the machine 6 on the drain 82 has been illustrated.

[0138] Layout and dimensioning Figure 11 illustrates an example of an installation according to the invention.

[0139] Machine 6 is shown in side view with its YY axis in a horizontal position. Only the two bearings 20 are visible in phantom representation from the outside for clarity. From left to right in this example are the output shaft 36 with its drive pinion, a bearing cover 37, the cam 44, a timing cover 39 and finally at the right end a brake cover 41 or closing plate.

[0140] The device 7 equipped with the flow meter 14 extends opposite a cylindrical external face 47 of the machine, in this case opposite the distribution cover 39. The axis XX of the conduit extends in a plane perpendicular to an axis YY of rotation of the machine. The length L of the flow meter, which corresponds to its direction along the axis of the conduit, extends in a direction parallel to the tangent to this face 43. In other words, it extends along the tangent to the circumferential direction to the axis YY. The device is in communication with a fluid orifice 43 of the machine via a pipe 45 bent in an L at 90° in the present example. This orifice 43 is for example a drain orifice. Positioned like this, it could also be a power supply orifice of the machine.

[0141] The device 7 has a total dimension L measured along the axis XX of the conduit less than or equal to a largest dimension T of the machine measured in a plane perpendicular to the axis YY of rotation of the machine, ignoring the fixing flanges 84. In this case, this length L is less than the width of the distribution cover 39.

[0142] Figure 12 illustrates another example of an installation according to the invention which differs from the previous example only in the following aspects. This time, the axis XX of the conduit is parallel to the axis YY of rotation of the machine. The device 7 remains in communication with an orifice not illustrated and is fixed to a base 49 of the distribution cover 39 which has orifices 51 for fixing this cover to other parts of the machine. The device 7 extends opposite the lateral faces of the distribution cover 39 and the brake cover 41 or closing plate. The device 7 is here connected to a port drilled in a plane substantially perpendicular to the axis YY of rotation of the machine, typically a drain orifice of the machine.

[0143] The device 7 has a total dimension L measured along the axis XX of the conduit less than or equal to a largest dimension M of the machine measured along the axis YY of rotation of the machine, excluding the shaft output 36. In this case, the length L of the device 7 is less than or equal to 150% of the length C of the distribution cover 39, both being measured along the direction of the axis YY. A similar example has been illustrated in Figures 13 to 15 and 17. Figures 13 to 15 are views of the same hydraulic machine equipped with the device 7, respectively in perspective, from the side and in end view, Figure 17 showing the device 7 alone.

[0144] The device 7 is here connected to a port drilled in a plane substantially perpendicular to the axis YY of rotation of the machine, typically a drain orifice of the machine. Figure 15 shows that, in axial view, the device 7 does not protrude beyond the overall diameter of the machine, even if the ears 84 or flanges of the casing used for fixing the machine 6 to an external frame are not taken into account. This overall diameter, without the ears 84, is here 232 mm, this value not being limiting. The device 7 also does not protrude from the base 49 of the distribution cover 39 in this example.

[0145] Figure 16 shows two examples of a mounting of the device on a power supply port of the machine 7, which port is typically drilled substantially on a plane parallel to the axis YY of the machine 7. Such connection planes for the hydraulic ports can be inclined up to 30° relative to the axis YY of the machine 7. The device is connected to the supply port by a substantially 90° elbow, so that the body of the flow meter is substantially parallel to the body of the machine 7, which reduces the overall size of the assembly. Two positions are shown, which can correspond to orientations of departures of hydraulic pipes, supply ducts 66 or discharge ducts 68. The figure illustrates that the device 7, in both positions, does not exceed the dimensions of the overall volume of the machine 6, including without taking into account the fixing lugs 84. The lugs 84 are this time carried by the bearing cover.Thus the device 7 is entirely included in the largest dimension T of the machine measured in a plane perpendicular to the YY axis without taking into account the ears, and in the largest dimension M of the machine measured along the YY axis without taking into account the shaft output 36.

[0146] Figures 18 and 19 illustrate a similar machine 6 of an installation according to the invention respectively in side and top view. The arrangement and orientation of the device 7 are of the type of those of Figure 11. The device 7 is connected to a supply port 43 of the machine, namely in the case of a motor one of the power ports which rotate the motor. This is for example a motor with a brake as in this example. The flow meter 7 is mounted with a connector 45 bent at 90°. It can be seen in the top view in Figure 19 that the device does not exceed the width of the machine. In particular, we find the cam 44, the distribution cover 39 and the brake cover 41. It can be seen in Figure 18 that the plane P in which the supply orifices are arranged is inclined relative to the axis YY of the machine.

[0147] Figures 20 and 21 illustrate a similar machine of an installation according to the invention respectively in side and top view. The arrangement of the device 7 is identical to that of Figures 18 and 19 except that its axis XX is now parallel to the axis YY of the machine. Here it protrudes from the machine in the longitudinal direction by less than a quarter of the length of the device 7 as seen in the top view of the machine in Figure 21. The other characteristics of the machine 6 are identical.

[0148] Generally speaking, it is interesting to size the device 7 according to at least one of the following characteristics:

[0149] - the device 7 has a total dimension L measured along the axis XX of the conduit less than or equal to 120% of a dimension l of the measurement zone measured along the axis of the conduit;

[0150] - the device 7 has a total dimension L measured along the axis XX of the duct less than or equal to 10.33 times, or even less than or equal to 8.6 times, a larger dimension d of the duct 10 in the measurement zone measured along a direction perpendicular to the axis of the duct. For example, L is 60 mm, d is 7 mm and the ratio is 8.6;

[0151] - the device 7 has a total dimension L measured along the axis XX of the conduit less than or equal to 4 times, or even 3.5 times, a larger dimension e of the device 7 in a plane perpendicular to the axis of the conduit. For example, L is 60 mm, e is 18 mm and the ratio is 3.33, and / or

[0152] - the measuring zone 21 has a length l less than or equal to 3.2 times a greater dimension d of the conduit 10 in the measuring zone measured in a direction perpendicular to the axis of the conduit. For example, l is 18 mm and d is 7 mm, for a ratio of 2.6.

[0153] The dimension d of the conduit is in this case its height.

[0154] These characteristics are to be compared with the space requirement for all sizes of fluid pipes, therefore all sizes of motors or pumps.

[0155] It can be provided that the device 7 does not exceed the overall volume of the machine 6 considered alone.

[0156] Similarly, if we define the smallest parallelepiped surrounding the machine, the device 7, in both positions, is entirely included in this parallelepiped. The same applies if we define the smallest cylinder with circular section surrounding the machine 6. These two shapes have a dimension T in a direction perpendicular to the axis YY and a dimension M along this axis.

[0157] Many modifications can be made to the invention. It is possible to provide that the sensor or one of the sensors forms an accelerometer or provides particle counting in the fluid.

[0158] The machine 6 according to the invention may have two drain ports. The device 7 may be connected to either one, however when the device is used to measure the drainage flow, only the drain port equipped with the device must be open. All drainage must then pass through the port connected to the device.

Claims

CLAIMS 1. Installation (2) comprising: - a hydraulic machine (6), - a device (7), and - at least one hydraulic fluid circuit (9) configured to put the device in communication with the machine, the device (7) comprising: - a hydraulic fluid conduit (10) having an internal face (12) extending along an axis (XX); - a flow meter (14) defining a measurement direction (D) in the conduit, the direction being inclined relative to the axis and intercepting the internal face, the flow meter delimiting a measurement zone in the conduit; and - at least one sensor (22, 24) separate from the flow meter, the sensor extending outside the measurement zone or in a plane (P1, P2) perpendicular to the axis and passing through the flow meter.

2. Installation according to the preceding claim in which the flow meter (14) is an ultrasonic flow meter.

3. Installation according to one of the preceding claims in which the conduit (10) is made of a material permeable to ultrasound, for example PEEK.

4. Installation according to one of the preceding claims in which the flow meter (14) is a flow meter measuring travel time.

5. Installation according to the preceding claim in which the flow meter comprises a first transceiver (16) and a second transceiver (18), the first transceiver and the second transceiver being aligned in the direction (D), the sensor (22, 24) extending outside the measurement zone or in a plane (P1, P2) perpendicular to the axis and passing through one of the first transceiver and the second transceiver.

6. Installation according to the preceding claim in which the first transmitter-receiver (16) has a transmission-reception axis (VV) coinciding with the direction (D) and the second transceiver (18) has a transmission-reception axis (MM) coinciding with the direction (D).

7. Installation according to claim 5 in which the first transceiver (16) has a transmission-reception axis (VV), and the second transceiver (18) has a transmission-reception axis (MM), at least one of the two transmission-reception axes being non-coincident with the direction (D).

8. Installation according to one of claims 1 to 3 in which the flow meter (14) is Doppler effect.

9. Installation according to one of the preceding claims in which the direction (D) forms an angle with the axis (XX) of between 20 and 70°.

10. Installation according to one of the preceding claims in which the internal face (12) has a cylindrical shape.

11. Installation according to one of the preceding claims in which the internal face (12) has a profile having a section which has a length greater than a width of the section.

12. Installation according to the preceding claim in which the section has a rectangular, oval or elliptical shape.

13. Installation according to one of the preceding claims in which the sensor or one of the sensors is a temperature sensor (22).

14. Installation according to one of the preceding claims in which the sensor or one of the sensors is a pressure sensor (24).

15. Installation according to claims 13 and 14 in which the temperature sensor (22) and the pressure sensor (24) are combined in an element mounted in the conduit (10).

16. Installation according to one of the preceding claims in which the sensor (22, 24) or one of the sensors is placed in a housing (28) provided in the conduit (10).

17. Installation according to the preceding claim in which the housing (28) opens into the internal face (12).

18. Installation according to claim 16 in which the housing (28) is separated from the internal face (12) by a wall (31).

19. Installation according to the preceding claim in which the circuit (9) comprises a drain.

20. Installation according to one of the preceding claims in which the device (7) has a total dimension (L) measured along the axis (XX) of the conduit less than or equal to 120% of a dimension (l) of the measurement zone measured along the axis of the conduit.

21. Installation according to one of the preceding claims in which the device (7) has a total dimension (L) measured along the axis (XX) of the conduit less than or equal to 10.33 times a largest dimension (d) of the conduit (10) in the measurement zone measured along a direction perpendicular to the axis of the conduit.

22. Installation according to one of the preceding claims in which the device (7) has a total dimension (L) measured along the axis (XX) of the conduit less than or equal to 4 times a largest dimension € of the device in a plane perpendicular to the axis of the conduit.

23. Installation according to one of the preceding claims in which the measuring zone (21) has a length (l) less than or equal to 3.2 times a largest dimension (d) of the conduit (10) in the measuring zone measured in a direction perpendicular to the axis (XX) of the conduit.

24. Installation according to one of the preceding claims in which the axis (XX) of the conduit extends in a plane perpendicular to an axis (YY) of rotation of the machine.

25. Installation according to the preceding claim in which the device (7) has a total dimension (L) measured along the axis (XX) of the conduit less than or equal to a largest dimension (T) of the machine measured in a plane perpendicular to the axis (YY) of rotation of the machine.

26. Installation according to one of claims 1 to 23 in which the axis (XX) of the conduit is parallel to an axis (YY) of rotation of the machine.

27. Installation according to the preceding claim in which the device (7) has a total dimension (L) measured along the axis (XX) of the conduit less than or equal to a largest dimension (M) of the machine measured along the axis (YY) of rotation of the machine.

28. Installation according to one of the preceding claims in which the device (7) comprises at least one end of the device a connection member (19) to the hydraulic circuit.

29. Installation according to one of the preceding claims in which the device (7) comprises at least one end of the device a connection member (19) to an orifice of the hydraulic machine (6).

30. Method in which: - a fluid flow rate is determined in an area of ​​a hydraulic conduit (10) in communication with a hydraulic machine (6), and - at least one quantity is measured from a fluid temperature and a fluid pressure in the conduit upstream or downstream of the zone.

31. Method according to the preceding claim in which the machine (6) operates as a pump.

32. Method according to claim 30 in which the machine (6) operates as a motor.

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