EP1355068B1 - Device for dividing or uniting a supply of fluid - Google Patents

Description

The present invention relates to a device for dividing or assembling a fluid flow rate according to the preamble of claim 1, comprising a casing which has at least one primary orifice which may be traversed by a primary flow of fluid and a plurality of secondary orifices capable of each passing through a secondary flow of fluid, and means for dividing the primary flow into secondary flows or for joining the secondary flow rates in primary flow.

We know, for example by FR 2 476 770 flow dividers in which a flow entering through the primary orifice is divided into two outflows by the secondary orifices by means of a floating drawer which connects, by restrictions, the secondary orifices to the primary orifice.

Despite the improvements made, to the pre-existing prior art, by FR 2 476 770 divisors of this type are relatively unreliable when the flow entering through the primary orifice varies significantly.

It is also known, for example by FR 2 199 836 , flow dividers consisting of several coupled gear motors. This technology is reliable, but dividers of this type are expensive and bulky. In some applications, it is necessary to divide a primary rate into more than two secondary rates. For these applications, the flow dividers of the aforementioned type comprise at least three or more gear motors which are coupled together. In this case, the cost of these dividers and their congestion are excessive.

We know by US Patent 4,475,870 a flow divider, which comprises the features of the preamble of claim 1.

The device of the invention not only serves as a flow divider, dividing a flow rate entering through the primary orifice into several outgoing flows through its secondary orifices, but also flow rate reunitor, bringing together several flow rates entering through the secondary ports in a flow rate exiting through the primary orifice.

The invention aims to improve the aforementioned prior art by proposing a divider / reunifier flow that is both simple and reliable.

This goal is achieved through the device according to claim 1.

The flow divider according to the invention is therefore similar in structure to a hydraulic motor with radial pistons. It thus comprises a cylinder block and a cam having a plurality of cam lobes. Depending on the direction of rotation of the cylinder block, the device according to the invention can be used as a flow divider or as a rate reunifier.

The distributor is fixed in rotation with respect to the cam, so that the different distribution ducts are associated with the different cam lobes. Indeed, for a given direction of rotation, the communication of a cylinder duct with a distribution duct always produces the same effect for the piston which slides in the cylinder connected to this cylinder duct. Considered in this direction of rotation, each cam lobe has a rising portion and a descending portion. If this direction of rotation is that in which the device is a flow divider, a piston cooperates with the rising portion of a cam lobe moving radially outwardly when the cylinder of the cylinder duct in which is disposed plunger is brought into connection with the primary distribution duct, and the same piston then cooperates with the descending portion of the same cam lobe when the cylinder duct is in communication with a secondary distribution duct. The fluid contained in the cylinder of this piston is then expelled through the secondary orifice to which is connected said secondary distribution duct. This secondary distribution orifice is said to be associated with the cam lobe considered since it is when a piston cooperates with this cam lobe that the fluid contained in the cylinder of this piston passes through this secondary orifice. Of course, it is possible to connect a plurality of secondary distribution conduits to the same secondary orifice, so that a group of at least one cam lobe is associated with each secondary orifice.

When the device operates as a flow divider, the flow rate of fluid entering through the primary orifice is divided into several secondary flow rates, each exiting through a secondary orifice. In order for these flow rates to be regular, each group of at least one cam lobe associated with a secondary orifice must be homokinetic, that is to say that the flow passing through this secondary orifice is constant and regular for a speed. constant rotation of the cylinder block relative to the housing.

Compared to the prior art, the devices according to the invention also allow, in a single casing, large flows with a greater number of secondary flows in a small space and can operate at higher pressures with better performance.

Those skilled in the art know that to achieve homokinetic motors, it is appropriate to choose the number of pistons in relation to the number of cam lobes and their angular coverage, as well as the layout of their profile. Each cam lobe group associated with a secondary orifice behaves like an elementary entity that must itself be homokinetic. For example, when all the cam lobes cover the same angular sector, and if the device comprises n cam lobes (where n is an integer at least equal to 2), then a device comprising 2 n + 1 pistons and n orifices secondary members each associated with one of the cam lobes, fulfills the condition that each cam lobe associated with a secondary orifice may be homokinetic. In this configuration, for example for a device with four secondary orifices and four identical cam lobes, it is imperative to provide at least nine pistons.

The device according to the invention may comprise a single primary orifice and several associated secondary orifices, each with a single cam lobe. In this case, if it comprises p cam lobes, where p is an integer greater than 2, then it divides the primary flow rate of fluid passing through the primary orifice into p secondary throughflows, each a secondary orifice, or it combines in a single primary flow p incoming secondary flows, each by a secondary orifice. The secondary flows are all equal to each other if the cam lobes are identical.

It is also conceivable with the device of the invention to divide a primary flow into several unequal secondary flows, or else to collect several unequal secondary flows in a single primary rate. The device may for example comprise four cam lobes and only three secondary orifices, two orifices each associated with a cam lobe, and a third secondary orifice associated with the two remaining cam lobes. In this case, if all the cam lobes are identical, the primary flow rate passing through the primary orifice can be divided into two secondary flow rates each corresponding to one quarter of this primary flow rate and a third secondary flow corresponding to half of the primary flow rate. .

Similarly, the device may comprise several primary orifices, while having advantages of secondary or primary orifices. Thus, for example, it can divide two primary flow rates each entering through a primary orifice into four secondary flows leaving by four secondary orifices, or bring these four secondary flow rates into two primary flows.

However, it is possible to have cam lobes which are not identical, in angular coverage and / or in profile, to obtain cam lobe groups constituting homokinetic entities and able to provide regular but different rates, in specific and accurate reports adapted to their use.

Advantageously, the device further comprises deactivation means capable of communicating the primary conduits and the secondary distribution conduits.

When all the primary and secondary distribution channels communicate with each other, the device is deactivated and the flow is no longer divided in the ratios imposed upon activation, but is distributed according to the flow requirements called to the secondary orifices. For example, the device is disposed on the discharge pipe of a pump for supplying two motors each driving a wheel of a machine. It is known that in order to avoid slip situations, the interposition of a flow divider between the supply or exhaust pipe of the motors and the pipe of the pump connected to it makes it possible to feed the two motors with the same flow rate and thus avoid slippage situations in which, if one of the wheels slips, the motor driving the wheel "consumes" the entire flow pumped by the pump, and the vehicle can not move. Of another on the other hand, when a vehicle is traveling in a turn, it is necessary for the outer wheel to be driven at a faster speed than the inner wheel. For this reason, for example, it may be interesting to deactivate the flow divider device.

It should be noted that one can choose to only partially disable the flow divider. Thus, for a four-wheel drive vehicle, the device can be interposed between the discharge pipe or suction of a pump and four supply or exhaust lines each connected to a motor driving one of the wheels of the craft. The device thus divides into four determined secondary flows (for example equal, if the wheels have equal diameters), the primary flow discharged by the pump or brings together four equal secondary flows in a primary conduit sucked by the pump.

The flow divider can be activated to avoid a slip situation when operating in a straight line, on difficult terrain, the machine. For road operation, it may wish to only partially disable the device, for example to negotiate turns.

As indicated above, each cam lobe is associated with a primary duct and a secondary distribution duct; the secondary orifice of the device to which this secondary distribution duct is connected is also associated with the same cam lobe. It is possible to deactivate the splitting or reunification of the flow at the secondary orifice under consideration, according to the imposed ratios, by interconnecting the primary duct and the secondary distribution duct associated with the lobe of the cam considered, while for other lobes cam, the primary and secondary distribution channels remain separate. Thus, the divider / reunitor device remains activated with respect to these cam lobes and flows in the last secondary orifices to which they are associated continue to be forced in imposed ratios.

It is thus possible to stop dividing the flow rate, according to the imposed ratio, between the motors driving the steering wheels of a vehicle, to allow these wheels to rotate at different speeds, including cornering, while continuing to divide / gather the flow rate, according to the imposed ratio, between the supply lines / exhaust engines driving the two other wheels, non-steering, of the vehicle.

Advantageously, the deactivation means are formed by the fact that primary and secondary distribution ducts (or all of these ducts) are able to be connected to a bore through openings disposed in this bore, and the device comprises a selector disposed in this bore and able to be controlled between a first position in which it isolates these openings from each other and a second position in which it makes communicate with at least some of these openings.

This bore is for example formed in the distributor.

Advantageously, the device has hydrostatic stop means for the cylinder block.

The device is thus simplified, since no axial abutment such as a bearing is necessary to retain the cylinder block with respect to an axial displacement, but the pressure of the fluid flowing in the device is used to form a hydrostatic stop.

Advantageously, the device comprises a pressure limiter adapted to communicate a secondary orifice with a pressure limiting conduit to limit the pressure of the fluid passing through said secondary orifice.

It is advantageous to associate a pressure limiter with a flow divider, to avoid overpressure in the lines fed by this divider, especially when they each serve to supply a hydraulic motor. Indeed, when the hydraulic motors drive the wheels of a machine, it happens that the pressure in a pipe can reach a value too high may damage the hydraulic motor, for example when turning or when the wheel driven by this engine meets a obstacle. With the invention, a pressure limiter may be a constituent element of the divider device or flow reunitor. The device can include as many pressure limiters as secondary ports. The device preferably comprises a single pressure limiter which can be used to limit the pressure in the secondary ducts by means of a set of valves, each subjected to the pressure of a secondary orifice and allowing the passage of fluid from the secondary orifice. to a common enclosure upstream of the pressure limiter.

According to one variant, the pressure limiting duct is connected to the primary orifice, which simplifies the constitution of the pressure limiter.

Advantageously, the device comprises a sensor for the speed of rotation of the cylinder block relative to the casing and a converter able to process the data captured by this sensor to determine the flow rate of fluid passing through the primary orifice or a secondary orifice as a function of this speed and thus achieve a flow meter.

This flowmeter is reliable and simple because it uses the most reliable data to know the flow delivered by the secondary ports, which is the speed of rotation of the cylinder block, the calculated flow being the product of this speed of rotation of the cylinder block by the cubic capacity considered. The converter may be a simple calculator or a microprocessor in whose memory the flow of fluid passing through each secondary orifice is entered for a complete revolution of the cylinder block. For each secondary orifice, this flow rate is a function of the number and the conformation of the cam lobes associated with this orifice, as well as the cylinder capacity of the cylinder block.

According to an advantageous arrangement, the cylinder block has a transverse face with marks and the sensor is disposed opposite this transverse face.

The marks can be formed by notches, teeth or other, located on the transverse face of the cylinder block, and the sensor can be formed by an inductive sensor, magnetic or optical, with respect to which markers scroll during the rotation of the cylinder block.

• la figure 1 est une vue en coupe axiale d'un dispositif conforme à l'invention, selon un premier mode de réalisation ;
• la figure 2 est une coupe partielle de ce dispositif selon la ligne II-II de la figure 1 sur laquelle, pour simplifier, le bloc-cylindres n'est pas représenté ;
• la figure 3 est une vue en coupe axiale du dispositif de l'invention, selon un deuxième mode de réalisation ;
• la figure 4 est une vue analogue à celle de la figure 3, pour un autre mode de réalisation ;
• les figures 5 et 6 sont des vues analogues, pour deux autres modes de réalisation.

The invention will be better understood and its advantages will appear better on reading the detailed description which follows, of embodiments shown by way of non-limiting examples. The description refers to the accompanying drawings in which:

• the figure 1 is an axial sectional view of a device according to the invention, according to a first embodiment;
• the figure 2 is a partial section of this device along line II-II of the figure 1 on which, for simplicity, the cylinder block is not shown;
• the figure 3 is an axial sectional view of the device of the invention, according to a second embodiment;
• the figure 4 is a view similar to that of the figure 3 for another embodiment;
• the figures 5 and 6 are similar views, for two other embodiments.

The device 10 figures 1 and 2 comprises a housing in three parts, respectively 10A, 10B and 10C, fixed together by screws 12 passing through axial bores 13. Inside the housing is disposed a cylinder block 14 mounted relative rotation relative to the housing screw with respect to an axis of rotation A. This cylinder block has a plurality of cylinders 16 arranged radially with respect to the axis A, in which pistons 18 are arranged able to slide in these cylinders. By their ends 18A remote from the axis of rotation A, the pistons can cooperate with a corrugated reaction cam 11 formed at the inner periphery of the portion 10B of the housing.

The cylinder block 14 comprises a cylinder duct 20 for each cylinder, which duct can be put in communication successively with a primary orifice OP of the casing and with a secondary orifice of this casing. On the figure 1 , only a secondary orifice OS4, present in the section plane, is shown. However, the positions of all the secondary orifices OS1, OS2, OS3 and OS4 and also that of the orifice OP are indicated in broken lines on the figure 2 , although these orifices are not in the section of this figure.

The device comprises a fluid distributor 22, which is integral in rotation with the housing by any appropriate means such as one or more pins 21, and which comprises primary distribution pipes 24P connected to the primary orifice OP. The device also comprises secondary distribution conduits 24S respectively connected to the different secondary orifices OS1 to OS4.

Thus, the primary orifice OP is the orifice, on the end face of the portion 10C of the housing, of an axial duct 26 which is formed in this portion 10C. This conduit 26 opens into a groove 28 which is formed between an axial face 10'C of the part 10C and an axial face 22 'of the distributor 22.

The primary distribution conduits 24P all open into this groove 28 to be connected to the primary orifice. They open also in a transverse distribution face 22A of the dispenser, in which they open through the primary dispensing orifices 30P.

The cylinder block has a transverse communication face 14A in which the cylinder ducts 20 open by communication orifices 20A. The orifices 30P and 20A are located at the same distance from the axis of rotation A, so that they can be placed in communication with each other during the relative rotation of the cylinder block and the housing. The transverse communication face 14A and the transverse distribution face 22A, which are both perpendicular to the axis A, are placed in mutual abutment, for example by means of compression springs 32 which constantly push the distributor 22 against the cylinder block 14 taking support in the bottom of the portion 10C of the housing.

The groove 28 forms an enclosure which is delimited around an area of the distributor 22 into which the primary distribution conduits 24P open to be connected to the primary distributor OP.

On the figure 2 , the conduits 24S and their orifices 30S are indicated; the positions of the conduits 24P and their orifices 30P are also indicated, although these are not visible in the plane of section.

On the upper half of the figure 1 the cylinder duct 20 is connected to a primary distribution duct 24P. In the lower half of this figure, the cylinder duct 20 is connected to a secondary distribution duct 24S.

In this case, the secondary distribution conduits 24S are not practiced in the distributor 22 but they are formed in the part 10A of the housing. The cylinder block 14 has a transverse end face 14B which is opposite the transverse communication face 14A and which bears against a bearing face 34 belonging to an element integral with the housing, which is in this case the part 10A of the casing, an inner transverse face of which forms the bearing face 34.

At least some cylinder ducts 20 have a portion 20B which extends between the transverse faces 14A and 14B of the cylinder block 14 and which is open, in the transverse communication face 14A, by a communication orifice 20A and, in the transverse end face, by an end port 20C.

The secondary distribution orifices 24S open in the bearing face 34 by secondary distribution orifices 305 which are able to communicate with the end ports 20C during the relative rotation of the cylinder block and the housing. Indeed, the orifices 20C and 30S are located at the same radial distance from the axis A. For simplicity, the cylinder ducts have a T-shape with a radial branch which opens into the bottom of the cylinders 16 and an axial branch which forms the portion 20B and extends rectilinearly between the faces 14A and 14B of the cylinder block.

Of course, it could be expected that only certain secondary distribution ducts are shaped like the secondary conduits 24S of the figure 1 . The device could perfectly include other secondary distribution ducts, formed in the distributor 22 and opening on the one hand in the transverse distribution face 22A by secondary distribution orifices able to communicate with the communication orifices during the relative rotation of the cylinder block and the casing and secondly in the opposite transverse face of the distributor facing secondary orifices made in the portion 10C of the housing.

The device of the figure 1 has hydrostatic abutment means for the cylinder block 14. More specifically, in the example shown, the bearing face 34 has a blind hole 34A located opposite each of the dispensing orifices 30P which are arranged in the transverse face of distribution 22A. In the example of the figure 1 all these dispensing orifices are the primary orifices 30P, but it may not always be so. Thus, when a cylinder duct communicates with one of these dispensing orifices 30P, it also communicates with one of these blind holes. This forms a chamber whose communication with the cylinder duct opens or closes as the communication of this cylinder duct with the dispensing orifice considered. This results in a balancing of the pressures and axial forces on both sides of the cylinder block.

Similarly, the transverse distribution face 22A has a blind hole 23A located opposite each of the secondary distribution orifices 24S which are arranged in the bearing face 34.

These hydrostatic stop means form an axial bearing for the cylinder block, during its rotation inside the housing. The device also comprises a radial force recovery bearing 36 which is formed by a bearing supported by a central pin 37 of the portion 10A of the housing. This bearing cooperates with the wall of a central bore 14 'of the cylinder block.

où

• Ppi est la pression à chaque orifice primaire,
• Qpi est le débit à chaque orifice primaire,
• Psi est la pression à chaque orifice secondaire,
• Qsi est le débit à chaque orifice secondaire.

The embodiment of the distributor 22, with the stepped axial faces 10'C and 22 ', makes it possible to use the fluid pressure in the groove 28 to permanently balance the thrusts exerted on the distributor by the pressure of the fluid contained in the 24P and 24S distribution ducts and to axially push the distributor towards the cylinder block. More specifically, on the figure 1 , the fluid contained in the distribution ducts 24S exerts its thrust on the distributor 22 via the cylinder ducts 20 and blind holes 23A. The shape of the groove 28 is determined taking into account the particularity of the flow divider according to the invention at the level of the relationship between the pressures at the secondary orifices and the pressure at the primary orifice: $$\underset{}{\Sigma }\left(\mathrm{ppi}\times \mathrm{qpi}\right)=\underset{}{\Sigma }\left(\mathrm{psi}\times \mathrm{qsi}\right)$$

or

• Ppi is the pressure at each primary orifice,
• Qpi is the flow at each primary orifice,
• Psi is the pressure at each secondary orifice,
• Qsi is the flow at each secondary orifice.

For example, for a flow divider having a primary orifice and four secondary orifices with division of the flow rate into four equal secondary flow rates, the sum of the pressures in the secondary orifices is equal to four times the pressure in the primary orifice, since the flow rate primary is equal to four times each secondary flow.

Of course, other types of axial support could be used, for example by choosing a stud distributor of the type described for a hydraulic motor in FR 2,701,736 .

The device of the figure 1 further includes an OF leak return port. This is connected to the interior of the housing by a leakage return duct which, in this case, comprises a first duct section 38A which opens into the region of the cam 11, and a second section of duct 38B which opens into the region of the interior space of the distributor 22, the latter having the shape of a ring.

The device of the figure 1 further comprises a sensor 40 of the rotational speed of the cylinder block relative to the housing. This is for example an inductive sensor disposed in a bore 41 of the portion 10A of the housing and held in a sealed manner in this part by means of a retaining assembly 42 comprising a screw. The end of the sensor is facing a region of the transverse end face of the cylinder block which has pins 44 spaced angularly from each other. By connections 43, the sensor 40 can be connected to a converter which counts the number of marks 44 running past this sensor per unit of time (which gives the speed of rotation of the cylinder block) and which deduces the flow of fluid passing through the various secondary orifices of the device, on the basis of stored parameters, relating to the cubic capacity of each elementary entity constituted by a group of one or more cam lobes associated with a secondary orifice.

On the figure 2 it can be seen that the cam 11 has four cam lobes, respectively 11A, 11B, 11C and 11D each having a rising ramp and a descending ramp. A primary distribution pipe 24P whose orifice 30P is represented on the figure 2 , and a secondary distribution pipe 24S whose secondary distribution orifice 30S is indicated on the figure 2 , are respectively associated with the rising ramps [s] 11A1 and descending [s] 11A2 of the cam lobe 11A in the direction of rotation R of the cylinder block. This means that when a cylinder duct is in communication with the orifice 30P, the piston located in the cylinder of this duct moves radially outwards with its end in contact with the ramp 11A1, while the same piston moves. radially inwardly with its end in contact with the ramp 11A2 when the same cylinder duct communicates with the orifice 30S. The secondary orifice OS1 to which this secondary distribution conduit 24S is connected is associated with the cam lobe 11A. In this case, the four secondary orifices OS1 to OS4 are respectively associated with each of the four cam lobes 11A to 11D.

We now describe the figure 3 , on which the same references as on the figure 1 , increased by 100, are used to designate the elements of the device of the figure 3 which are analogous to those of the device of the figure 1 .

The device 110 of the figure 3 comprises deactivation means capable of communicating the primary distribution conduits 124P and the secondary distribution conduits 124S. Specifically, the primary distribution conduits 124P have openings 125P which are disposed in a bore 122B of the distributor 122. Similarly, the secondary distribution conduits 124S have openings 125S which are also disposed in this bore 122B.

The device 110 comprises a selector 150, which is arranged in the bore 122B and which is able to be controlled between a first position, represented on the figure 3 , in which it insulates the openings 125P and 125S from each other and a second position in which it makes at least some of these openings communicate with each other.

In the example shown, the outer periphery of the selector 150 has a groove 152 which, in the second position of this selector in which it is moved in the direction of the arrow F, is opposite, at the same time, the openings 125P and 125S openings.

It can be provided that all the distribution conduits 124P, 124S have openings which open into the bore 122B, and that all these openings are arranged to be placed in communication in the second position of the selector 150, in which case the assembly of the dividing or reuniting device is deactivated in this second selector position.

Alternatively, it may be provided that a part of the device is deactivated by choosing for example that only certain secondary distribution conduits 124S have openings 125S which open into the bore 122B.

In the example shown, the displacement control means of the selector 150 between its two positions comprise elastic return means 154 which constantly remind this selector in its first position. This is a spring that bears against the end of the pin 137 of the portion 110A of the housing. These control means also comprise a hydraulic control chamber 156 that can be supplied with fluid under pressure to move the selector to its second position. For this purpose, a control duct 158 is disposed in the part 110C of the casing and opens into the chamber 156 which, in the position of the selector 150 represented on the figure 3 , has a minimum volume. In the example of the figure 3 it has therefore been chosen that, without pressure in the chamber 156, the selector 150 is in its first position. In other words, the splitter or debit splitter device is enabled by default. One could choose an opposite situation in which the control means would be reversed compared to those of the figure 3 and would include a return spring constantly reminding the selector in its position in which it disables the device.

Furthermore, any means for controlling the movement of the selector can be used, such as hydraulic, mechanical, electromechanical or electronic means, in particular to make the switching progressive and / or staggered depending on the position of the selector 150.

Alternatively, provision can be made for individual deactivation devices of each flow division by interposing a selector between each secondary distribution duct and a primary distribution duct to allow direct communication between these ducts. These selectors may be constituted by known components such as pilot valves, logic valves or slide valves.

In the example of the figure 3 the secondary distribution orifices OS are formed in the same part 110C of the casing as the primary distribution orifice OP. The secondary distribution conduits 124S are formed in the distributor 122 and open in its transverse distribution face 122A through the secondary distribution orifices 130S able to communicate with the communication orifices 120A during the relative rotation of the cylinder block and crankcase. More specifically, the conduits 124S each comprise a first section 124S1 which is disposed in the distributor 122. It is this first section which is connected by a radial branch to the opening 125S located in the bore 122B. These distribution ducts also comprise a second section 124S2 which is formed in the part 110C of the casing. These two parts are put in communication by a ring 160 whose central bore is aligned with the portions 124S1 and 124S2. This ring forms a seat for a compression spring 132 which constantly urges the dispenser to bear against the cylinder block. It cooperates sealingly with a cavity of the dispenser in which it is housed and constitutes a balancing pad dimensioned such that all of these pads allows the balancing of the distributor.

In addition to the primary and secondary orifices, the device 110 includes a leak return port OF into which a leak return conduit having two sections 138A and 138B opens.

In the embodiment of the figure 3 , the device 110 comprises a pressure limiter 170 which is adapted to communicate a secondary orifice OS with a pressure limiting duct to limit the pressure of the fluid passing through the secondary orifice.

On the figure 3 this pressure limiting duct is connected to the primary orifice OP. More precisely, the pressure limiter comprises first ducts 170S which are each capable of being connected to one of the secondary orifices OS, a second duct 170L which is capable of being connected to the pressure-limiting duct and an enclosure 170E which is connected to each first conduit 170S by a non-return valve 172 and which is connected to the second conduit 170L by a valve 174.

Each check valve 172 can open to communicate the first conduit 170S with which it cooperates with the enclosure 170E when the pressure in the first conduit becomes greater than the pressure in the chamber. The valve 174 can open to communicate this chamber with the second conduit 170L when the pressure in the chamber reaches a predetermined threshold. More precisely, the valve 174, in its differential valve variant represented on the figure 3 , opens when the difference of the pressures in the enclosure 170E and in the conduit 170L reaches a predetermined threshold. Other pressure limiting valve variants may be used.

For this, the movable member 176 of the valve is permanently biased against its seat by a prestressed spring 178, the preload has a predetermined value. The valve comprises a valve body 181, which is disposed in a 110D element integral with the housing, in which are formed the conduits 170L and 170S, and the enclosure 170E. The valve body is sealingly disposed in a bore 182 of this element 110D, and its interior space can communicate with the enclosure 170E by communications such as holes 184. When the movable member 176 of the valve 174 is pushed back against its seat, it closes the communication between the enclosure 170E and the conduit 170L.

In the example shown on the figure 3 the first ducts 170S are able to be connected to the secondary orifices OS via the secondary distribution conduits 124S. More specifically, the housing portion 110A which has the bearing face 134 against which the extreme transverse face 114B of the cylinder block is in abutment present connecting ducts 186S which open in this bearing face through holes of connection 186 'able to communicate with the end ports 120C of the axial portions 120B of the cylinder ducts passing through the cylinder block from one side to the other, between its communication face 114A and its transverse end face 114B during the rotation relative to the cylinder block and the housing, which allows the connecting conduits 186S to communicate with the secondary distribution conduits 124S. The second conduit 170L of the pressure limiter 170 communicates with the main orifice OP by another connecting conduit 186L made in the part 110A of the housing, itself in communication with a primary distribution conduit 124P via a cylinder conduit 120. In fact, the conduit 186L opens in the bearing face 134 of the portion 110A of the housing by a connecting port 186'L able to communicate with the orifices 120 during the rotation of the block. cylinders. The number of pistons at least equal to 2n + 1, n being the number of secondary orifices, guarantees a permanent communication between the conduit 170L and the primary distribution conduit 124P, via the conduit 186L and at least one cylinder duct 120.

Thus, when the fluid pressure passing through a secondary orifice OS becomes excessive, that is to say greater than a predetermined threshold, or greater than the pressure in the primary orifice OP increased by a predetermined value, the excess of pressure is returned to the primary orifice.

The element 110D in which is disposed the valve 174 is flanged on the portion 110A of the housing. Of course, it could be an integral part of the housing.

We now describe the embodiment of the figure 4 , on which the elements common to that of the figure 1 are assigned the same references as in this figure, increased by 200.

On the figure 4 , the cylinder block 214 has an internal bore 214 'in which the cylinder ducts 220 open by communication ports 220A.

The distributor comprises meanwhile an axial portion 222 secured to the housing which extends in this bore 214 'of the cylinder block. The distribution ducts 224P and 224S open on the outer periphery 222 'of this axial portion 222 into distribution orifices, respectively 230P and 230S. The communication orifices 220A and the dispensing orifices are adapted to be arranged facing each other during the relative rotation of the cylinder block and the housing. For example, the axial portion 222 which forms the distributor is actually an axial extension of the portion 210C of the housing which passes through the bore 214 'of the cylinder block and also a bore 210'A of the portion 210A of the housing which then presents a disc shape whose center is hollowed out.

For example, the primary distribution ducts 224P are arranged in a star inside the distributor 222 while being all connected to the main orifice OP by a common axial duct section, 224PA.

On their side, the secondary distribution ducts 224S are all respectively connected to a secondary orifice OS by a respective axial connecting branch 224SL.

The connection between the bore 214 'of the cylinder block and the external axial periphery 222' of the distributor 222 is sealed by two rings or annular segments 227 disposed respectively in two transverse planes between which the communication and distribution orifices extend. . The cylinder block is guided axially by two simple friction washers 229 or needle stops. An alternative is to replace the seals 227 by two annular grooves for receiving leaks and promote the formation of a hydrostatic bearing.

The device of the figure 4 further comprises a device for pressurizing the inner space 273 of the housing adapted to put this space in communication with the primary or secondary orifice which is at the lowest pressure. This device comprises check valves 292 disposed on pressurizing conduits 290 respectively connecting the primary orifice OP and the secondary orifices OS to the space 273 and allowing the passage of the fluid only from the space 273 of the housing to the primary or secondary orifice that is at the lowest pressure. More specifically, for each pressurization duct (there is one for each primary or secondary orifice), the valve 292 is interposed between the pressurization duct and the inner space 273 of the casing surrounding the cylinder block, the seat of the valve being the edge of a pressurizing piercing 292 'which extends between each duct 290 and the space 273. Each pressurizing duct 290 is connected to a primary orifice OP or secondary bone OS respectively via the common axial section 224PA of the primary distribution ducts or by an axial linkage branch 224SL of a secondary distribution duct.

Unlike the previous figures, the flow divider of the figure 4 There is no leakage return line and in operation the pressure in the space 273 increases due to internal leakage. When the fluid pressure in this space 273 becomes too high, that of the valves 292 which is located in the pressurization duct 290 at the lower pressure opens to allow the circulation of the fluid from the space 273 to this pressurization duct 290, therefore to the primary or secondary orifice at the lowest pressure.

Springs 217 disposed in the cylinders 216 keep the pistons 218 against the cam 211 even when the piston 218 is subjected at both ends, in its cylinder and in the space 273, at substantially equal pressures.

The interest of the device of the figure 4 This is because the pistons 218 of the flow divider are thus subjected to lower pressure differences than when the leak return line (generally at a pressure of the order of 1 bar) is present. The pistons, and consequently the cam 211, are then subjected to less significant efforts. The efficiency and the lifetime of the device are thus increased. This is made possible because the flow divider pistons are not intended to provide driving torque, as is the case in a neighboring structure engine. In addition, the pressurization of the crankcase, which in a motor can cause leakage problems in the rotating seals on the motor output, does not present any difficulty for a flow divider without output shaft.

We now describe the figure 5 on which elements common to the figure 3 are assigned the same references, increased by 200.

As in the example of figure 4 , the cylinder block 314 of the figure 5 has an axial bore 314 'in which extends an axial portion 322 which forms the distributor. The cylinder ducts 320 open into the bore 314 'into communication orifices 320A to which, during the relative rotation of the cylinder block and the distributor, the distribution orifices 330P and 330S of the distribution conduits 324P and 324S.

The distributor 322, formed by an axial portion of the portion 310C of the housing, has a bore 322B in which are arranged 325P and 325S openings of the distribution ducts, respectively 324P and 324S. In this bore 322B is disposed a selector 350 which is adapted to occupy a first position, represented on the figure 5 in which it insulates the openings 325P and the openings 325S and a second position, in which it is moved in the direction of the arrow G, to communicate with each other at least some of the openings 325P and 325S.

For this, in the example shown, the outer periphery of the distributor 350 has a groove 352 which can be disposed opposite openings 325P and 325S, themselves arranged between two transverse planes. Control means of the selector 350 comprise a spring 354 constantly reminding it in its first position and a control chamber 356 capable of being supplied with fluid by a control duct 358.

The primary distribution channels 324P are all placed in communication with the primary orifice OP by being connected to an annular groove 328 with which said primary orifice OP permanently communicates. The secondary distribution conduits 324S are connected to the secondary orifices OS by radial branches.

We now describe the device of the figure 6 , on which the same references, increased by 300 compared to the figure 3 , describe the same elements as on the figure 3 . The cylinder block 414 is rotatably supported vis-a-vis the three-part housing 410A, 410B and 410C by a bearing incorporating the radial and axial forces. In this case, it is a bearing 436 four points of contact, which cooperates with an extension 435 of the cylinder block, located under the 410B portion of the housing. The cylinder ducts 420 open into a transverse communication face 414A of the cylinder block into communication ports 420A. The primary orifice OP of the device is connected to primary distribution conduits 424P by an axial duct 426 in communication with a groove 428 formed between the stepped axial periphery of the distributor 422 and the stepped axial periphery of the portion 410C of the casing.

Overall, the 424P and 424S distribution ducts are similar to those of the figure 3 .

The device 410 of the figure 6 can be deactivated, partially or totally, using a selector 450 substantially similar to the selector 150 of the figure 3 . The device 410 includes a leak return port OF into which a leak return conduit having a plurality of sections, 438A and 438B, opens.

The portion 410A of the housing has the shape of a disk pierced at its center by a bore 410'A. An axial extension 415 of the cylinder block extends into this bore, with respect to which it is sealed with one or more seals 415 '. This extension of the cylinder block has a central cavity 490, provided with spline 492 which thus forms a driving output for the rotational locking of the cylinder block with an external element to be driven, such as a small motor shaft.

Indeed, the flow divider according to the invention is not specifically made to deliver a torque-engine and that is why the device of Figures 1 to 5 is devoid of motor output. However, it is possible to use the rotation of the cylinder block to drive a small motor shaft, for example for applications such as an auxiliary pump, an angular encoder or any machine element to be driven at a speed proportional to the flow rate through the flow divider. .

It should be noted that the cylinder block is pierced by a bore 438C for bringing back between the external transverse face 414B of the cylinder block and the portion 410A of the casing the fluid coming from leaks in the bore 422B of the distributor in which is disposed the selector 450.

Claims (26)

1. A device (10; 110; 210; 310; 410) for splitting or combining a flow of fluid, said device comprising a casing (10A, 10B, 10C; 110A, 110B, 110C; 210A, 210B, 210C; 310A, 310B, 310C; 410A, 410B, 410C) that is provided with at least one primary orifice (OP) suitable for passing a primary flow of fluid, and with a plurality of secondary orifices (OS1, OS2, OS3, OS4; OS), each of which is suitable for passing a respective secondary flow of fluid, and means for splitting the primary flow into secondary flows or for combining the secondary flows into a primary flow, which means comprise a cylinder block (14; 114; 214; 314; 414) mounted to move in rotation relative to the casing about an axis of rotation (A) and having a plurality of cylinders (16; 116; 216; 316; 416) disposed radially about said axis, pistons (18; 118; 218; 318; 418) being suitable for sliding in the cylinders and co-operating with a reaction cam (11; 111; 211; 311; 411) constrained in rotation with the casing, the cylinder block having a cylinder duct (20; 120; 220; 320; 420) for each cylinder;
   said device being characterized in that the cam (11; 111; 211; 311; 411) is undulating, in that the pistons co-operate with the cam via their ends that are remote from the axis of rotation, in that it further comprises a fluid distributor (22; 122; 222; 322; 422) that is constrained in rotation with the casing and that is provided with primary distribution ducts (24P; 124P; 224P; 324P; 424P) connected to the primary orifice (OP), and secondary distribution ducts (24S; 124S; 224S; 324S; 424S) connected to respective ones of the various secondary orifices (OS), and in that each cylinder duct of the cylinder block is suitable, while the cylinder block and the casing are moving in rotation relative to each other, for being alternately connected to a primary distribution duct and to a secondary distribution duct of the distributor.
2. A device according to claim 1, characterized in that it further comprises deactivation means (150, 350, 450) suitable for causing the primary ducts and the secondary ducts to communicate with one another.
3. A device according to claim 2, characterized in that primary and secondary distribution ducts (124P, 124S; 324P, 324S; 424P, 424S) are suitable for being connected to a bore (122B; 322B; 422B) via openings (125P, 125S; 325P, 325S) disposed in said bore, and in that it further comprises a selector (150; 350; 450) disposed in said bore and suitable for being caused to go between a first position in which it isolates said openings from one another and a second position in which it causes at least some of said openings to communicate with one another.
4. A device according to any one of claims 1 to 3, characterized in that the cylinder block (214; 314) has an internal bore (214'; 314') into which the cylinder ducts (220; 320) open out via communication orifices (220A; 320A), and in that the distributor has an axial portion (222; 322) that extends in said bore of the cylinder block, the distribution ducts (224P, 224S; 324P, 324S) opening out in the outside periphery of said axial portion (222; 322) into distribution orifices (230P, 230S; 330P, 330S), the communication orifices and the distribution orifices being suitable for being disposed facing one another while the cylinder block and the casing are moving in rotation relative to each other.
5. A device according to any one of claims 1 to 3, characterized in that the cylinder block (14; 114; 414) has a communication face (14A; 114A; 414A) that extends transversely to the axis of rotation and in which the cylinder ducts (20; 120; 420) open out via communication orifices (20A; 120A; 420A), while the distributor (22; 122; 422) has a transverse distribution face (22A; 122A; 422A) in which at least the primary distribution ducts (24P; 124P; 424P) open out via primary distribution orifices (30P; 130P; 430P), said transverse faces being in mutual abutment and the communication orifices (20A; 120A; 420A) and the primary distribution orifices (30P; 130P; 430P) being suitable for being disposed facing one another while the cylinder block (14; 114; 414) and the distributor (22; 122; 422) are moving in rotation relative to each other, and in that the primary orifice (OP) is connected to an enclosure (28; 128; 428) defined around a zone of the distributor (22; 122; 422) in which the primary distribution ducts (24P; 124P; 424P) open out so as to be connected to said primary orifice (OP).
6. A device according to claim 5, characterized in that the cylinder block (14; 114) has a transverse end face (14B; 114B) opposite from said transverse communication face (14A; 114A), and in abutment against a bearing face (34; 134) belonging to an element (10A; 110A) fixedly connected to the casing, and in that at least certain cylinder ducts (20; 120) have a portion (20B; 120B) that extends between said transverse faces (14A; 14B; 114A; 114B) of the cylinder block (14; 114) and that is open, in the transverse communication face (14A; 114A), via a communication orifice (20A, 120A), and, in the transverse end face (14B; 114B), via an end orifice (20C; 120C).
7. A device according to claim 5 or claim 6, characterized in that at least certain secondary distribution ducts (124S; 424S) are provided in the distributor (122; 422) and open out in the transverse distribution face (122A; 422A) via secondary distribution orifices (130S; 430S) suitable for communicating with the communication orifices (120A; 420A) while the cylinder block and the casing are moving in rotation relative to each other.
8. A device according to claim 6 or claims 6 and 7, characterized in that at least certain secondary distribution ducts (24S) are provided in said element (10A) fixedly connected to the casing, and open out in said bearing face (34) via secondary distribution orifices (30S) suitable for communicating with the end orifices (20C) while the cylinder block and the casing are moving in rotation relative to each other.
9. A device according to any one of claims 1 to 7, characterized in that it has hydrostatic abutment means (34A; 23A) for the cylinder block (14).
10. A device according to claims 6 and 9, characterized in that the bearing face (34) is provided with a blind hole (34A) situated facing each of the distribution orifices (30P) that are disposed in the transverse distribution face (22A).
11. A device according to claim 9 and to any one of claims 7 to 10, characterized in that the transverse distribution face (22A) is provided with a blind hole (23A) situated facing each of the secondary distribution orifices (30S) that are disposed in the bearing face (34).
12. A device according to any one of claims 1 to 11, characterized in that it further comprises a pressure limiter (170) suitable for causing a secondary orifice (OS) to communicate with a pressure limiter duct (186, 120, 124P, 126) for limiting the fluid pressure passing through said secondary orifice.
13. A device according to claim 12, characterized in that the pressure limiter duct (186 or 186L, 120, 124P, 126) is connected to the primary orifice (OP).
14. A device according to claim 12 or claim 13, characterized in that the pressure limiter (170) has first ducts (170S) each of which is suitable for being connected to a respective one of the secondary orifices (OS), a second duct (170L) that is adapted to be connected to the pressure limiter duct, and an enclosure (170E) that is connected to each first duct via a check valve (172) and that is connected to the second duct via a valve (174), each check valve being suitable for opening to cause the first duct (170S) with which it cooperates to communicate with the enclosure (170E) when the pressure in said first duct becomes higher than the pressure in the enclosure, and the valve (174) being suitable for opening to cause the enclosure to communicate with the second duct when the pressure in said enclosure reaches a determined threshold.
15. A device according to claim 14, characterized in that the first ducts (170S) are suitable for being connected to the secondary orifices (OS) via the secondary distribution ducts (124S).
16. A device according to claim 6, and to claim 14 or 15, characterized in that the first ducts (170S) are suitable for being connected to the secondary distribution orifices (124S) via link ducts (186S) provided in said element (110A) integral with the casing and opening out in the bearing face (134) of said element via link orifices (186S') suitable for communicating with the end orifices (120C) while the cylinder block and the casing are moving in rotation relative to each other.
17. A device according to any one of claims 14 to 16, characterized in that the second duct (170L) is suitable for being connected to the primary orifice (OP) via the primary distribution ducts (124P).
18. A device according to claim 6 and to any one of claims 14 to 17, characterized in that the second duct (170L) is suitable for being connected to the primary distribution orifices (130P) via link ducts (186L) provided in said element (110A) fixedly connected to the casing and opening out in the bearing face (134) of said element via link orifices (186'L) suitable for communicating with the end orifices (120C) while the cylinder block and the casing are moving in rotation relative to each other.
19. A device according to any one of claims 1 to 18, characterized in that it is further provided with a leak return duct (38A, 38B; 138A, 138B; 338; 438A, 438B, 438C) connected to a space internal to the casing.
20. A device according to any one of claims 1 to 11, characterized in that it further comprises means for putting the internal space of the casing (273) under pressure, which means are suitable for putting said space into communication with that one of the primary and secondary orifices (OP, OS) that is at the lowest pressure.
21. A device according to claim 20, characterized in that each of the orifices, be they primary or secondary orifices (OP, OS), is connected to the internal space of the casing (273) via a pressurization duct (290) in which a check valve (292) is disposed that allows fluid to flow only in the direction going from the internal space of the casing towards the pressurization duct that is at the lowest pressure.
22. A device according to any one of claims 1 to 21, characterized in that it further comprises a sensor (40) for sensing the speed of rotation of the cylinder block (14) relative to the casing (10A, 10B, 10C), and a converter suitable for determining the flow rate of fluid passing through the primary orifice (OP) or through a secondary orifice (OS) as a function of said speed, and thus for forming a flow meter.
23. A device according to claim 22, characterized in that the cylinder block (14) has a transverse face (14B) with reference marks (44), and in that the sensor (40) is disposed facing said transverse face.
24. A device according to any one of claims 1 to 23, characterized in that the casing has more than two secondary orifices (OS1, OS2, OS3, OS4; OS).
25. A device according to any one of claims 1 to 24, characterized in that it is not provided with a drive outlet.
26. A device according to any one of claims 1 to 24, characterized in that it is provided with a drive outlet (490).

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