EP3677775A1 - Micro-hydro generation plant - Google Patents

Abstract

The present invention relates to a hydraulic micro-central (1) for pressurizing a fluid (2), remarkable in that it comprises at least: - a motor (5) driving in rotation a crankshaft (6) in two directions of rotation R or R ', - two piston pumps (7) arranged in opposition, alternately set in motion by said crankshaft (6) and capable of pressurizing the fluid (2), - a gear pump (8 ) arranged in the extension of said crankshaft (6) and capable of pressurizing the fluid (2), and- a freewheel (9) integral with the free end of said crankshaft (6), disposed between said piston pumps (7 ) and gear pump (8), and capable of driving or not driving in rotation the output shaft (81) of said gear pump (8) when the crankshaft (6) rotates in the direction R or R '.

Description

Technical field of the invention

The present invention relates to the general field of pressurizing a hydraulic fluid. More specifically, it targets a high-performance hydraulic power station of small dimensions, hereinafter referred to as a micro-power plant.

State of the art

In the field of pressurizing a hydraulic fluid, it is known to use mainly gear pumps or piston pumps.

Gear pumps, which use the combined profile of two gears to transfer and increase the pressure of a fluid, are simple in design and easy to maintain, and their cost is relatively low. In addition, there are two types of gear pumps: external gear pump or internal gear pump.

The first type of gear pump is simple to use but has the disadvantage of having a rather low flow rate. In fact, the space available between the face of the teeth of the toothed wheels and the body of the pump tends to increase as the external gear pump wears out, which has the consequence of increasing the volumetric losses and d '' weaken the volumetric efficiency of such a pump.

The second type of gear pump has the advantage of being very quiet and having a better volumetric efficiency, especially at low rotational speed. However, this type of gear pump generally has the disadvantage of having a rather high energy consumption.

Piston pumps offer the best volumetric efficiency, but are the most expensive.

Gear pumps are advantageously used to deliver a high flow rate while piston pumps are rather to obtain a high pressure. However, to obtain a high flow rate or a high pressure, it is generally necessary to use bulky pumps.

Summary of the invention

The aim of the present invention is to propose a hydraulic power station having high performance, namely: the highest possible hydraulic flow, a pressure as high as possible while consuming the minimum amount of energy, said power station being small in size so that it can be easily implemented on mobile devices.

• un moteur associé à des moyens d'inversion pour inverser le sens de rotation dudit moteur et entrainant en rotation un vilebrequin dans un sens de rotation R ou dans le sens opposé R',
• deux pompes à piston disposées en opposition, mises alternativement en mouvement par la rotation dudit vilebrequin et aptes à aspirer du fluide et à le refouler sous pression vers la sortie de la microcentrale,
• une pompe à engrenages disposée dans le prolongement dudit vilebrequin et apte à aspirer du fluide et à le refouler sous pression vers la sortie de la microcentrale, et
• une roue libre solidaire de l'extrémité libre dudit vilebrequin, disposée entre lesdites pompes à pistons et la pompe à engrenages, et apte à entrainer en rotation l'arbre de sortie de ladite pompe à engrenages lorsque le vilebrequin tourne dans le sens R et à ne pas entrainer en rotation ledit arbre de sortie lorsque ledit vilebrequin tourne dans le sens opposé R'.

In accordance with the invention, a hydraulic microcentral is therefore proposed for pressurizing a fluid, remarkable in that it comprises at least:

• an engine associated with reversing means for reversing the direction of rotation of said engine and causing a crankshaft to rotate in a direction of rotation R or in the opposite direction R ',
• two piston pumps arranged in opposition, alternately set in motion by the rotation of said crankshaft and capable of sucking fluid and delivering it under pressure towards the outlet of the micro-power plant,
• a gear pump arranged in the extension of said crankshaft and capable of sucking in fluid and of discharging it under pressure towards the outlet of the microcentral, and
• a freewheel secured to the free end of said crankshaft, disposed between said piston pumps and the gear pump, and capable of rotating the output shaft of said gear pump when the crankshaft rotates in the direction R and at do not rotate said output shaft when said crankshaft rotates in the opposite direction R '.

The motor is advantageously either an electric motor associated with a reduction gear and means for reversing the electric current to reverse the direction of rotation of said motor, or a pneumatic motor associated with means for reversing the input / output circuit of said hydraulic motor for reverse the direction of rotation of said motor.

• un réservoir contenant le fluide, et
• une plaque de fermeture dudit réservoir, le moteur, les deux pompes à piston, la pompe à engrenages et la roue libre étant alors directement ou indirectement solidaires de ladite plaque de fermeture du réservoir et disposés à l'intérieur de ce dernier.

Preferably, the microcentral comprises

• a reservoir containing the fluid, and
• a closing plate of said tank, the motor, the two piston pumps, the gear pump and the freewheel then being directly or indirectly integral with said tank closing plate and arranged inside the latter.

The plate advantageously includes an outlet for pressurized fluid, corresponding to the outlet of the microcentral, and a return of fluid to the reservoir.

The plate also comprises a first pipe fitted with a non-return valve and relating the delivery of the gear pump to the outlet of pressurized fluid, and a second pipe connecting the delivery of the set of two piston pumps and said first pipe downstream of said non-return valve.

The direction of rotation of the motor is preferably reversed when the microcontroller reaches a set value Vc.

The set value Vc is advantageously a determined pressure level of the fluid at the outlet of the micro-power station or an absorption of the current determined at the terminals of the motor.

Brief description of the figures

• [Fig 1] est une vue en coupe longitudinale de la centrale hydraulique selon l'invention,
• [Fig 2] est une vue de dessus de la centrale de la figure 1 sans sa plaque supérieure,
• [Fig 3] est une vue en coupe horizontale éclatée de la centrale de la figure 1 sans son réservoir de fluide.

Other advantages and characteristics will emerge more clearly from the description which follows of an embodiment of the invention with reference to the appended figures in which:

• [ Fig 1 ] is a view in longitudinal section of the hydraulic power station according to the invention,
• [ Fig 2 ] is a top view of the plant of the figure 1 without its top plate,
• [ Fig 3 ] is an exploded horizontal sectional view of the power plant of the figure 1 without its fluid reservoir.

Description of the embodiments

On the Figures 1 to 3 , there is shown the high-performance hydraulic power station 1 of small dimensions according to the invention, hereinafter called microcentral 1, the latter being able to pressurize a fluid 2, advantageously oil.

• un réservoir 3 contenant un volume de fluide 2,
• une plaque 4 de fermeture dudit réservoir 3,
• un moteur 5 entrainant en rotation un vilebrequin 6 dans un sens de rotation R ou dans le sens opposé R',
• deux pompes à piston 7 disposées en opposition, mises alternativement en mouvement par la rotation dudit vilebrequin 6 et aptes à aspirer du fluide 2 contenu dans le réservoir 3 et à le mettre sous pression,
• une pompe à engrenages 8 disposée dans le prolongement dudit vilebrequin 6 et apte à aspirer du fluide 2 contenu dans le réservoir 3 et à le mettre sous pression, et
• une roue libre 9 solidaire de l'extrémité libre dudit vilebrequin 6, disposée entre lesdites pompes à pistons 7 et la pompe à engrenages 8, et apte à entrainer en rotation l'arbre de sortie 81 de ladite pompe à engrenages 8 lorsque le vilebrequin 6 tourne dans le sens R et à ne pas entrainer en rotation ledit arbre de sortie 81 lorsque ledit vilebrequin 6 tourne dans le sens R' opposé.

Thus, the microcentral 1 advantageously comprises at least:

• a reservoir 3 containing a volume of fluid 2,
• a plate 4 for closing said reservoir 3,
• a motor 5 rotating a crankshaft 6 in a direction of rotation R or in the opposite direction R ',
• two piston pumps 7 arranged in opposition, set in motion alternately by the rotation of said crankshaft 6 and capable of sucking fluid 2 contained in the reservoir 3 and putting it under pressure,
• a gear pump 8 arranged in the extension of said crankshaft 6 and capable of sucking fluid 2 contained in the reservoir 3 and of putting it under pressure, and
• a free wheel 9 secured to the free end of said crankshaft 6, disposed between said piston pumps 7 and the gear pump 8, and capable of driving in rotation the output shaft 81 of said gear pump 8 when the crankshaft 6 rotates in the direction R and not to rotate said output shaft 81 when said crankshaft 6 rotates in the opposite direction R '.

It is understood here that the expression "a gear pump 8 disposed in the extension of said crankshaft 6" defines the relative position of the gear pump (8) relative to the crankshaft (6), that is to say that the microcentral (1) comprises, one after the other, a motor (5), a crankshaft (6) then a gear pump (8).

All the constituent elements of the microcentral 1, namely: the motor 5, the two piston pumps 7, the gear pump 8 and the freewheel 9, are directly or indirectly integral with said tank closure plate 4 3 and arranged inside the latter.

In the exemplary embodiment described, the microcentral 1 is associated with a hydraulic installation, not shown, operating in a closed circuit. Consequently, the plate 4 advantageously comprises an outlet 41 of fluid 2 under pressure, corresponding to the outlet 10 of fluid 2 under pressure from the microcentral 1, and a return 42 of fluid 2 in the reservoir 3. The plate 4 further comprises a first pipe 43 advantageously provided with a non-return valve 44 and relating the discharge of the gear pump 8 and said outlet 41 of fluid 2 under pressure, and a second pipe 45 relating the discharge of the assembly two piston pumps 7 and said first pipe 43 downstream of said non-return valve 44.

However, the micro-power plant 1 may also be associated with an external tank of greater or lesser capacity and with a hydraulic installation which does not operate in a closed circuit, without departing from the scope of the present invention; the plate 4 will then be modified and will in particular not include a fluid return 2.

The motor 5, which is associated with reversing means for reversing its direction of rotation, is either an electric motor associated with a reduction gear 51 and means for reversing the electric current, not shown in the figures, for reversing the direction of rotation of said motor 5, or according to an embodiment not shown, a pneumatic motor associated with means for reversing the input / output circuit of said pneumatic motor to reverse the direction of rotation of said motor 5. The inversion means are therefore either means for reversing the electric current, or means for reversing the input / output circuit.

Thus, with this configuration of the microcentral 1, when the engine 5 drives the crankshaft 6 in the direction of rotation R, the free wheel 9 rotates the output shaft 81 of said gear pump 8. The latter then sucks fluid 2 contained in the reservoir 3 and discharges it into the first pipe 43 up to the outlet 41 of fluid 2 from the plate 4, the fluid 2 passing through a non-return valve 44. Simultaneously, the set of two piston pumps 7 sucks fluid 2 contained in the reservoir 3 and discharges it into the second pipe 45 to the outlet 41 of fluid 2 from the plate 4 via the first pipe 43. With the direction of rotation R, at the outlet 41 for fluid 2 from the plate 4, a high flow rate of fluid 2 is obtained at low pressure.

The term "low pressure" designates a fluid pressure 2 of less than 70 bars and by "high pressure" a fluid pressure 2 of more than 300 bars. Likewise, here is designated by "low flow" a fluid flow 2 less than 0.5 l / min (liter per minute) and by "high flow" a fluid 2 flow greater than 2 l / min.

When the microcentral 1 reaches a set value Vc, the direction of rotation of the engine 5 is reversed and the latter then drives the crankshaft 6 in the direction of rotation R ', the free wheel 9 no longer drives the shaft of rotation outlet 81 of said gear pump 8 which no longer sucks fluid 2 contained in the reservoir 3. However, the assembly of the two piston pumps 7 still sucks fluid 2 contained in the reservoir 3 and discharges it into the second pipe 45 up to the outlet 41 for fluid 2 from the plate 4 via the first pipe 43. However, in order to prevent the fluid 2 under pressure supplied by the assembly of the two piston pumps 7 from entering the gear pump 8 , a non-return valve 44 blocks access to the latter. With the direction of rotation R ′, at the outlet 41 for fluid 2 from the plate 4, a low flow rate of fluid 2 is obtained at high pressure.

The set value Vc can be, for example, at a determined pressure level of the fluid 2 at the outlet 10 of the microcentral 1 or an absorption of the current determined at the terminals of the electric motor 5.

It is therefore clearly understood that, in the hydraulic micro-unit according to the invention, the specific freewheel 9 and the reversal of the direction of rotation allow the motor 5, according to its direction of rotation, to drive either the piston pumps 7 alone, or the piston pumps 7 and the gear pump 8 in particular in order to have a high flow rate.

Thus, at a determined motor torque, the gear pump 8 will be disengaged by reversing the direction of rotation of the motor 5, the piston pumps 7 having no direction of rotation for their operation, the flow of fluid delivered. by the hydraulic micro-power station 1 according to the invention then passes from a high high at low pressure to a low flow, that of the piston pumps 7 alone, a high pressure, and this for the same motor torque as in the first direction of rotation .

The microcentral 1 may include more than two piston pumps 7 without departing from the scope of the present invention.

Those skilled in the art will have no difficulty in implementing and dimensioning the elements necessary for the proper functioning of the micro-power plant 1 such as, for example, strainers for sucking the fluid 2 contained in the tank 3, pipes for connecting the delivery of the various pumps to the first and second pipes 43,45 or else ball or needle bearings and supports.

It is understood that thus configured the microcentral 1 according to the invention allows to obtain high performance while being particularly compact.

• un débit de fluide 2 à 70 bars de l'ordre de 2,5 l/mn, lorsque le moteur tourne dans le sens R,
• un débit de fluide 2 à 500 bars de l'ordre de 0,5 l/mn, lorsque le moteur tourne dans le sens R'.

According to an example of nonlimiting sizing, a microcentral 1 provided with a motor 5 with two directions of rotation either pneumatic of 360 W at 6 bars of air, or electric of 400 W at 24 V, makes it possible to obtain the following characteristics :

• a fluid flow rate 2 to 70 bars of the order of 2.5 l / min, when the engine rotates in the direction R,
• a fluid flow rate 2 to 500 bars of the order of 0.5 l / min, when the engine rotates in the direction R '.

The microcentral 1 according to the invention finds a particular application in the locking or clamping of workpieces by hydraulic cylinders where a rapid approach is required at low pressure and a blocking at high pressure.

Finally, it goes without saying that the examples of microcentral 1 in accordance with the invention which have just been described are only specific illustrations, in no way limiting the invention.

Claims (7)

Hydraulic micro-central (1) for pressurizing a fluid (2), characterized in that it comprises at least: a motor (5) associated with reversing means for reversing the direction of rotation of said motor (5) and causing a crankshaft (6) to rotate in a direction of rotation R or in the opposite direction R ', - two piston pumps (7) arranged in opposition, alternately set in motion by the rotation of said crankshaft (6) and capable of sucking fluid (2) and discharging it under pressure towards the outlet (10) of the microcentrale (1 ), - a gear pump (8) arranged in the extension of said crankshaft (6) and capable of sucking fluid (2) and of delivering it under pressure towards the outlet (10) of the microcentral (1), and - a freewheel (9) integral with the free end of said crankshaft (6), disposed between said piston pumps (7) and the gear pump (8), and capable of rotating the output shaft (81 ) of said gear pump (8) when the crankshaft (6) rotates in the direction R and not to rotate said output shaft (81) when said crankshaft (6) rotates in the opposite direction R '. Microcentral (1) according to claim 1 characterized in that the motor (5) is either an electric motor associated with a reduction gear (51) and means for reversing the electric current to reverse the direction of rotation of said motor (5), either a pneumatic motor associated with means for reversing the input / output circuit of said hydraulic motor to reverse the direction of rotation of said motor (5). Microcentral (1) according to any one of claims 1 or 2 characterized in that it comprises - a reservoir (3) containing the fluid (2), and - a plate (4) for closing said reservoir (3), the motor (5), the two piston pumps (7), the gear pump (8) and the freewheel (9) then being directly or indirectly integral with said plate (4) for closing the reservoir (3) and arranged inside the latter. Microcentral (1) according to claim 3 characterized in that the plate (4) has an outlet (41) of fluid (2) under pressure, corresponding to the outlet (10) of the microcentral (1), and a return (42 ) of fluid (2) in the reservoir (3). Microcentral (1) according to claim 4 characterized in that the plate (4) comprises a first pipe (43) provided with a non-return valve (44) and relating the discharge of the gear pump (8) and the outlet (41) of fluid (2) under pressure, and a second pipe (45) relating the discharge of the assembly of the two piston pumps (7) and said first pipe (43) downstream of said check valve back (44). Microcentral (1) according to any one of claims 1 to 5 characterized in that the direction of rotation of the motor (5) is reversed when the microcentral (1) reaches a set value Vc. Microcentral (1) according to claim 6 characterized in that the setpoint Vc is a determined pressure level of the fluid (2) at the outlet (10) of the microcentral (1) or an absorption of the current determined at the terminals of the motor (5).

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