FR2862119A1 - Hydraulic motor chamber separating membrane is in form of bellows element with at least one spiral corrugation. - Google Patents

Abstract

The bellows membrane has at least one spiral corrugation and a variable thickness at least at the center. The motor containing the membrane is designed to convert the energy of a fluid under pressure into an alternating motion. An independent claim is also included for a method of making the bellows comprising injection-molding a plastic in a two part mold with the parts corresponding to its opposite faces and rotating the mold to create a spiral.

Description

2862119 HYDRAULIC ENGINE WITH HELICOIDAL BELLOWS

  The present invention relates to a hydraulic motor with a helical bellows capable of converting the energy of a fluid under pressure into reciprocating movement, said motor being capable of being incorporated in a metering pump.

  This type of metering pump comprises an injection device and / or pumping ensuring the transfer of an amount of additive from an additive reservoir in the pressurized fluid as a function of the flow rate or a volume of said fluid. Such devices for injecting and / or pumping additives are numerous and well known to those skilled in the art.

  In a known manner, the energy of the pressurized fluid is used to operate the device for injecting and / or pumping additive. For this purpose, a hydraulic motor is used to convert the energy of the pressurized fluid into reciprocating movement of an actuator capable of controlling the injection device and / or pumping.

  The present invention relates to such a hydraulic motor capable of converting the energy of a fluid under pressure into reciprocating movement, and more specifically to a membrane or bellows.

  A first type of hydraulic motor said diaphragm is shown schematically in Figure 1. It comprises on the one hand an enclosure 10 in which is disposed a single membrane 11 dividing said enclosure into two chambers 12.1 and 12.2, and secondly, a distributor 13 capable of occupying two stable positions, a first position in which the fluid inlet 14 is connected to the first chamber 12.1 and the outlet 15 of the fluid is connected to the second chamber 12.2, and a second position in the second chamber 12.2; wherein the fluid inlet 14 is connected to the second chamber 12.2 and the outlet 15 of the fluid is connected to the first chamber 12.1. The tilting in one or the other of the positions of the distributor 13 is controlled by the movements of the membrane 11, especially when the latter is in the extreme high or low position.

  Thus, when the inlet 14 is connected to the chamber 12.2, the central portion of the membrane tends to deform upwards and to expel the fluid present in the chamber 12.1 towards the outlet 15. In the upper position of the central portion of the the membrane 11, the distributor 13 switches and the inlet 14 is then connected to the chamber 12.1 which causes the deformation of the central portion of the membrane 11 downwards and the evacuation of the fluid from the chamber 12.2 to the outlet 15 .

  An actuator 16 kinematically connected to the central portion of the membrane 11 performs reciprocating movement ensuring the operation of a device 15 for injection and / or pumping not shown.

  This arrangement does not give full satisfaction for the following reasons. Due to its design, this type of hydraulic motor is relatively bulky, the two-chamber chamber and the distributor can not combine and being disjoint. Moreover, this type of motor generally provides a short stroke of the actuator which may not be suitable for certain applications. To overcome this drawback, a membrane is used. But in this case, it is necessary to provide a guide element inside the membrane which makes the complex more complex. In all cases, it is noted that the existing membranes deteriorate rapidly increasing substantially the operating costs.

  A second type of so-called stepped piston hydraulic motor is described in patent U5-3,937,241 and shown schematically in FIG.

  This type of engine comprises two pistons 20 and 21, of different diameters, the piston 21 having a larger diameter than the piston 20, capable of sliding respectively in two cylinders 22 and 23 and delimiting three chambers, a so-called upper chamber. 24 disposed above the piston 21, a so-called intermediate chamber 25 disposed between the two pistons 20, 21 and a so-called lower chamber 26 disposed below the piston 20.

  The kinetically linked pistons 20 and 21 are connected to an actuator 27 capable of reciprocating so as to ensure the operation of a not shown injection and / or pumping device.

  From a fluid point of view, the inlet 28 of the fluid is connected to the lower chamber 26 and the outlet 29 of the fluid is connected to the intermediate chamber 25. Two valve 30 and 31 distributor are also provided, one 30 connecting the lower chamber 26 to the upper chamber 24 and the other 31 connecting the upper chamber 24 to the intermediate chamber 25, the two valves 30, 31 being respectively passing and blocked alternately.

  Thus, when the valve 30 is blocked, the pressurized fluid enters the lower chamber 26, the pistons are translated upwards and the fluid present in the upper chamber 24 is discharged to the intermediate chamber 25, the valve 31 being passing, then to the outlet 29. When the pistons arrive in the high position, the valves 30 and 31 rock, the valve 30 becoming on and the valve 31 blocked. In this case, the fluid exerts on the pistons a resultant which tends to push said pistons downwards, the surface of the piston 21 being greater than that of the piston 20. Thus, the fluid fills the upper chamber 24 while the translation towards the low tends to expel the fluid from the intermediate chamber 25 to the outlet 29.

  This type of engine solves some problems of hydraulic diaphragm motors. Thus, the stroke of the actuator is generally greater and the distributor can be integrated with the piston which contributes to improving the compactness of the assembly.

  Despite these improvements, this hydraulic motor does not give full satisfaction. Indeed, the sealing means between the pistons and the cylinders tend to degrade rapidly which tends to increase the operating costs of such devices. Moreover, jerk phenomena appear regularly when the pistons slide in the cylinders which can affect the proper functioning of the assembly. In addition, even if the compactness of the device is improved compared to hydraulic diaphragm motors, it is not yet optimal. Finally, the controls of the tilting of the flaps are relatively complex.

  Also, the present invention aims to overcome the disadvantages of the prior art by proposing a new membrane structure or bellows more resistant, the bellows being capable of being incorporated in a hydraulic motor.

  For this purpose, the invention relates to a bellows that can be used as a membrane so as to define at least two chambers, characterized in that it comprises at least one helical corrugation.

  Other features and advantages will become apparent from the following description of the invention, a description given by way of example only, with reference to the appended drawings in which: FIGS. 1 and 2 are diagrams illustrating the hydraulic motors of 3A and 3B are diagrams of the motor of the invention according to two states, - Figures 4A and 4B are perspective views of a bellows according to the invention respectively in the deployed state and FIG. 5 is a perspective view of the engine with a partial cutaway, FIG. 6A is a section along a vertical plane of the engine in a first state called intake, FIG. 6B is a section of the engine in FIG. a second state called discharge, - Figures 7 and 8 are views in two directions of the elastic means of compression, and - Figures 9A and 9B are perspective views illustrating the actuating means according to two states respectively resp to the intake and discharge phases.

  FIGS. 3A and 3B show a hydraulic motor according to the invention capable of converting the energy of a fluid under pressure into reciprocating motion. This engine is more particularly intended for a metering pump and, coupled with an injection device and / or pumping, it allows to inject an additive into a fluid.

  This hydraulic motor comprises an enclosure 100 in which are reported two bellows 101 and 102 so as to define three chambers, a first chamber Ve bounded by the lower part of the enclosure 100 and the lower surface of the bellows 102, a second chamber Vs delimited by the upper surface of the bellows 102 and the lower surface of the bellows 101 and a third chamber Vi delimited by the upper surface of the bellows 101 and the upper part of the chamber 100.

  The bellows 101 and 102, arranged in substantially parallel fashion, are capable of deforming so that their central portions move along a longitudinal axis 103, their respective peripheries being integral with the enclosure 100. The central portions gussets 101 and 102 are interconnected so as to be kinematically connected. An actuator 104 is connected to said bellows at the central portions, the latter being capable of performing reciprocating movements, a resultant of which is oriented along the longitudinal axis 103. Preferably, the actuator 104 translates axially. longitudinal 103. In known manner, the actuator 104 is connected to an injection device and / or pumping, not shown, in the case of a metering pump. This connection and the guide means of said actuator are not detailed because they are within the reach of the skilled person and are not essential elements of the invention.

  The engine also comprises an inlet conduit 105 of fluid under pressure connected to the chamber Ve and an outlet conduit 106 connected to the chamber Vs. It also comprises a distributor 107 capable of occupying two states, a first state called admission, corresponding to Figure 3A, in which it isolates the chamber Vs from the chamber Vi and fluidly connects the chamber Ve and the chamber Vi and a second said discharge state, corresponding to Figure 3B, in which it isolates the chamber Ve of the chamber Vi and fludically connects the chamber Vi and the chamber Vs. Thus, the volume of the chamber Vi increases during the admission phase and decreases during the discharge phase. This periodic volume variation, corresponding to a motor cycle, induces the reciprocating movement of the actuator 104.

  The hydraulic motor of the invention thus takes advantage of existing devices without their disadvantages. Thus, the bellows 101 and 102 do not wear out peripherally like the pistons of the motors of the prior art because of the friction. Furthermore, the fact of providing three chambers provides a substantially similar operation to piston engines at the fluid distribution.

  In order to obtain a relatively large stroke of the central part of the bellows, and thus of the actuator 104, without guiding in the manner of the unwinding membranes of the prior art, the bellows 101 and / or 102 is a helical bellows and comprises at least one helical corrugation 108. Thus, in section along a radius, the membrane comprises in the radial direction a succession of corrugations which are not concentric but come from at least one continuous helical corrugation, ranging from the largest diameter to the smallest. Alternatively, the bellows may comprise several helical corrugations juxtaposed.

  This spiral configuration provides the bellow increased structural strength even for long strokes and allows it to deform in a preferred direction corresponding to the longitudinal axis 103 and to obtain a final deformation flat.

  Advantageously, the thickness of the bellows varies and becomes smaller at the center of the bellows. This characteristic makes it possible to obtain a regular deformation of the bellows from its periphery to its center and to limit the risks of occurrence of bearings and a significant stretching in the intermediate zones.

  For a better compactness, the bellows 101 and 102 are substantially coaxial and their conicities in the deployed position are oriented in the same direction so that the bellows 102 in the extended position enters the bellows 101, as shown in Figures 3B and 6B .

  These bellows are generally made of plastic by injection molding. Given the small thickness of the bellows, the mold is not completely closed at the beginning of injection, the two parts of the mold corresponding to the faces of the bellows not being pressed against each other, so as to guarantee filling said mold. At the time of closure, a relative rotational movement between the two mold parts is produced to orient the material in the spiral direction so as to impart improved structural strength to the bellows.

  According to another characteristic of the invention, for greater compactness, the distributor 107 is disposed at the central portions of the bellows.

  To this end, the bellows 101 and 102 each comprise, on either side of the deformable intermediate zone of the substantially rigid zones, a first external annular zone 9.1, respectively 109.2, integral with the chamber 100 and a second zone. central annulus 110.1, respectively 110.2, comprising an orifice 111. 1, respectively 111.2. To ensure the connection of the central portions of the bellows 101 and 102, at least one bridge 112 is provided to connect the central annular zones 110.1 and 110.2. Preferably, several bridges 112 are provided, spaced apart, so as to let the fluid from then the center of the bellows to the chamber Vs. As shown in Figures 5, 6A and 6B, the actuator 104 is integral with the central annular zone 110.2 of the bellows 102. according to one embodiment, the actuator 104 is in the form of a tube, fitted into the orifice 111.2, which extends downwards inside the chamber Ve, said tube comprising at the periphery at least one window allowing in particular to communicate the outside and the inside of the tube.

  In addition, the distributor 107 comprises a first valve 113 capable of occupying two positions, a first so-called blocked position corresponding to the intake phase in which said valve 113 isolates the chamber Vs and a second so-called conducting position corresponding to the phase of discharge in which said valve 113 allows the passage of fluid from the chamber Vi to the chamber Vs, and a second valve 114 may occupy two positions, a first so-called blocked position corresponding to the discharge phase in which said valve 114 isolates the chamber Ve and a second so-called conductive position corresponding to the intake phase in which said valve 114 allows the passage of fluid from the chamber Ve to the chamber Vi.

  According to a preferred embodiment, the first valve 113 is in the form of a funnel with a flared upper portion 115 capable of cooperating with a seat 116 formed at the orifice 111.1 of the central annular area 2811119 9 bellows 101, a median portion 117 in the form of duct capable of communicating the chamber Ve and the chamber Vi and a lower end 118 engageable with a seat 119 formed at the upper edge of the orifice 111.2 of the central annular zone 110.2 of the bellows 102 or at the end of the actuator 104 fitted into the orifice 111.2 of the central annular zone 110.2 of the bellows 102.

  To ensure a satisfactory seal at the seats 116, 119, the first valve 113 comprises a deformable zone 120, in the form of a reduction in thickness, between the flared portion 115 and the duct 117. To ensure a better seal, the lower end 118 of the valve 113 and the seat 119 corresponding are conical, as shown in the various figures.

  The second valve 114 comprises a substantially spherical portion 121 capable of cooperating with a seat 122 formed either at the lower edge of the orifice 111.2 of the central annular zone 110.2 of the bellows 102 or at the level of the actuator 104 fitted into the orifice 111.2 of the central annular zone 110.2 of the bellows 102.

  According to another characteristic, the dispenser 107 comprises operating means ensuring the passage from the locked position to the passing position of the valve 113 and the passage from the passing position to the locked position of the valve 114 simultaneously or slightly shifted and vice versa. These operating means are illustrated in detail in FIGS. 7, 8, 9A and 9B.

  These operating means comprise (a) a ring 123 attached to the upper face of the central annular zone 110.1 of the bellows 101 with at least two radial stops 124 advantageously arranged each at the end of an arm 125 extending radially relative to to the ring 123 outwardly, (b) a nut 126, connected to the valves 113 and / or 114, capable of translating alternately along an axis substantially coaxial with the axis 103, as well as (c) means 2862119 compression elastics 127 interposed between the radial stops 124 and the nut 126 so that said nut occupies two stable positions, a first low position, illustrated by Figure 9A, corresponding to the discharge phase, and a second high stable position , illustrated by Figure 9B, corresponding to the intake phase.

  This type of operating means is more particularly advantageous because it makes it possible to obtain two stable positions and provides a sealing pressure of the valves on their respective seats independent of the pressure of the fluid, which makes it possible to have a good seal at all timing of the engine cycle.

  According to a preferred embodiment, the elastic compression means 127 comprise a spring wire, shaped so as to constitute at least two radial branches 128 with outer curved portions 129 capable of cooperating with the radial stops 124, in particular with grooves 130, said radial branches 128 being connected by curved portions 131 capable of cooperating with the nut 126, in particular with grooves 132 formed on the periphery of said nut 126, the outer curved portions 129 being separated by a distance greater than that separating the radial stops 124 so that the spring, formed flat without stress, is prestressed between the radial stops 124 and tends to arrange the nut 126 in the two stable positions, low or high. Figure 8 illustrates the shape of the prestressed spring 127.

  Advantageously, the spring 127 comprises four radial branches 128 whose outer curved portions 129 cooperate with four radial stops 124. According to a preferred arrangement, the connection between the nut 126 and the valves 113, 114 is made in the following manner.

  The nut 126 comprises an orifice 133, preferably coaxial with the axis 103, in which is slidable a rod 134 connected to the spherical portion 121 of the valve 114, extending inside the conduit 117 of the valve 113, said nut 126 being capable of bearing against two axial abutments, a first axial abutment 135, as illustrated in FIG. 6A, so as to operate the valve 113 in the locked position and the valve 114 in the driving position, and a second axial abutment 136 , as illustrated in FIG. 6B, so as to operate the valve 113 in the passing position and the valve 114 in the locked position.

  According to a preferred embodiment, the first axial abutment 135 is obtained thanks to a shoulder formed at the rod 134.

  According to another characteristic of the invention, the valves 113 and 114 are not rigidly connected but via damping means.

  For this purpose, the free end of the rod 134 of the valve 114 comprises a shoulder 137 and the valve 113 comprises a disc 138, connected by arms 139 to the conduit 117, disposed in a plane substantially perpendicular to the axis 103, to the above the nut 126, in which is provided an orifice 140 allowing the passage of the rod 134, a compression spring 141 being interposed between the shoulder 137 and the disk 138, the lower surface of said disk 138 acting as second stop function axial 136.

  The compression spring 141 acts as a damper between the valves 113 and 114 and, depending on its setting, allows the sealing pressure of the two valves 113 and 114 to be adjusted. A screw is screwed to the end of the stem. 134 acting as a shoulder 137 may allow this setting.

  The compression spring 141 also allows slightly shifting the position change of the two valves as will be explained later.

  In addition to the operating means, tilting means are provided to trigger the tilting and the displacement of the nut from one stable position to the other. For this purpose, stops are provided in the chamber at the axis 103, the first high trigger 142 triggers the tilting of the high position of the nut to the lower position corresponding to the passage of the discharge phase to the admission phase, and a second low trip stop 143 triggering the tilting of the low position of the nut to the high position corresponding to the passage of the intake phase to the discharge phase.

  The operation of the engine is now described with regard to the various figures.

  At the start of the intake phase, the bellows 101 and 102 are deployed conically, the valve 113 is in the locked position, the valve 114 is in the conducting position so that the pressurized fluid is introduced into the chamber Vi . During this phase, the nut 126 is in a low stable position pressed against the first axial abutment 135.

  The central portions of the bellows 101 and 102 move downward, the fluid exerting a resultant on said bellows facing downwards.

  Figure 6A illustrates the motor just before the phase change.

  At this time, the lower part of the valve 114 abuts against the second low trigger abutment 143. By continuing to deform, the bellows cause the phase change. Thus, the valve 114 being stationary, the translation of the central portions of the bellows and in particular of the ring 123 causes the change of stable position of the nut 126 which is translated to the high stable position. Thus, the nut 126 bears against the second axial stop 136, causing the passage of the valve 113 in the driving position, the latter causing shifted by means of the spring 141 the passage of the valve 114 in the locked position. At this time, the chamber Ve is isolated and the rooms Vi and Vs communicate with each other, which corresponds to the phase of discharge. The fluid then exerts pressure on the bellows 102 upwards and tends to deform the assembly so that the central portions of the bellows move upwards to the state shown in FIG. 6B.

  At this time, the upper end of the valve 114 abuts against the first high trigger stop 142. By continuing to deform, the bellows cause the phase change. Thus, the valve 113 being stationary, the translation of the central portions of the bellows and in particular of the ring 123 causes the change of stable position of the nut 126 which is translated to the low stable position. Thus, the nut 126 bears against the first axial abutment 135, causing the passage of the valve 114 in the driving position, the latter causing shifted by means of the spring 141 the passage of the valve 113 in the locked position.

  So we come back from the admission phase.

  The bellows hydraulic motor of the invention is more particularly suitable for metering pumps, the actuator 104 controlling by its reciprocating movement a device for injecting and / or pumping an additive.

  In an indifferent manner, the additive can be injected into one of the chambers Ve, Vi, Vs, the chamber Ve being preferred so as to obtain a better homogenization of the fluid / additive mixture at the pump outlet.

  Of course, the invention is obviously not limited to the embodiment shown and described above, but covers all variants, especially with regard to the materials and dimensions of the various elements. Likewise, the hydraulic motor can be used in other applications when it is necessary to convert the energy of a fluid under pressure.

  Finally, the helical bellows can be used in other types of hydraulic motor, for example those described in the preamble.

Claims (1)

  1. Bellow may be used as a membrane so as to delimit two chambers characterized in that it comprises at least one corrugation (108) helical.   2. bellows according to claim 1, characterized in that the thickness of the bellows varies and becomes lower at the center of the bellows.   3. bellows according to claim 1 or 2, characterized in that it is made of plastic by injection molding.   A hydraulic motor capable of converting the energy of a fluid under pressure into reciprocating motion, comprising at least one bellows according to any of the preceding claims 1 to 3.   5. A method for obtaining a bellows according to any one of claims 1 to 3, said bellows being obtained by means of a mold in two parts corresponding to the two faces of said bellows, characterized in that it consists injecting material into a mold that is not completely closed at the beginning of the injection, the two parts of the mold not being pressed against each other, so as to guarantee the filling of said mold, and to close the mold by generating a relative rotational movement between the two mold parts to orient the material in a spiral direction.