ITPD20100083A1 - HYDRAULIC MACHINE WITH VARIABLE FLOW - Google Patents

Description

TITLE

VARIABLE FLOW HYDRAULIC MACHINE

DESCRIPTION

The present patent relates to hydraulic machines and in particular concerns a new hydraulic machine with variable displacement.

Hydraulic machines such as pumps or motors which move fluids such as gases, vapors or more or less viscous liquids are known.

For example, gear pumps or gear motors are known, comprising a chamber containing at least two toothed wheels mutually engaged, and where the fluid is set in motion by the rotation of said toothed wheels and by the volume variation in the chamber due to the meshing of the cogwheel teeth.

The pump capacity is determined according to the rotation speed of the wheels and the geometry of the teeth.

Therefore, to vary the pump flow rate it is necessary to vary the number of revolutions of the gear wheels.

Lobe pumps or lobe motors are also known, comprising a chamber containing at least lobed rotating elements, with one or more lobes, rotating on parallel axes. Their synchronized rotation causes the motion of the fluid from the suction port towards the delivery port.

Also in this case the pump flow rate is a function of the geometry of the lobes and their rotation speed.

The subject of the present patent is a new type of variable displacement hydraulic machine.

The aim of the present invention is to vary the flow rate of fluid without varying the speed of rotation of the rotors.

Another object of the present invention is to vary the flow rate of fluid continuously.

Another object of the present invention is to ensure the correct directionality of the flow generated by the machine, thanks to suitable sealing members.

These and other direct and complementary aims are achieved by the new type of hydraulic machine with variable flow rate, suitable to be used both as a motor and as a pump, ie as a driving machine or as an operating machine.

The present invention comprises in its main parts a casing or containment body identifying at least one chamber or volume of transit of a fluid, in which at least two rotating members or main rotors are housed, rotating in a synchronized manner and mutually engaged, and where one or both of said main rotors are able to translate axially with respect to said chamber to vary their wet working surface in axial length, ie the working surface which is affected by the transit of said fluid.

In particular, said rotating members or main rotors are of the gear or lobe type, ie each comprise at least one wheel provided with teeth or lobes.

Inside said casing, the new machine comprises at least two further rotating members, hereinafter called complementary filling members, each coupled to a relative said main rotor and comprising a substantially cylindrical external surface for rotation, and a hollowed seat of dimensions and shape corresponding to the shape of the relative main rotor and suitable for axial insertion of said main rotor in all or part of its axial length.

Said main rotors can therefore translate in said chamber with respect to said complementary members, translating in the relative seats of said complementary members, so as to vary in the axial length of mutual coupling and their wet working surfaces.

Each of said complementary members is able to rotate integrally with the relative main rotor with respect to said casing and has the function of filling inside the chamber the volume portions surrounding the relative main rotor in correspondence with the non-wet working surface, i.e. the wet working surface of its main rotor. Inside said casing, the new machine also includes additional filling elements or elements, designed to fill the volumes of said chamber above and below said main rotors, to correctly convey the flow of fluid.

Said filling elements are in fact sealed on said casing or containment body of the machine, so that the fluid is not diverted above or below the main rotors.

One or more of said filling elements are adapted to translate correspondingly to said main rotors, so as to reduce or increase the axial length exposed to the transit of the fluid.

The new machine therefore comprises main rotors which can be coupled together for a variable axial length, so as to increase or decrease the working surface of the rotors and therefore correspondingly increase or decrease the pump flow rate without varying the speed of the rotors.

In this way, the translation of one or more of said main rotors, and consequently of said filling elements, actually causes the variation of the dimensions of the chamber as well as the variation of the wet working surface of the main rotors, so that the flow rate of fluid is substantially varied by varying the geometry of the system but without varying the rotation speed of the main rotors.

The capacity of the machine can be varied continuously, according to the translation of said one or more main rotors and of said one or more filling elements, which can be adjusted with great precision. The functionality of the machine is very similar to the volumetric gear or lobe machines.

Said main rotors are each connected to a shaft capable of imparting the rotary motion to said rotors in the case in which the new machine is used as a pump, while they are capable of transmitting the rotary motion of the rotors in the case in which the machine is used as a motor. .

The lobes or teeth of said rotors can have any suitable geometry and can be in any number.

The new machine is suitable for use with any type of fluids, such as gases, vapors, liquids of varying viscosity, mixtures, sludges, etc.

The characteristics of the present invention will be better clarified by the following description with reference to the drawing tables, attached by way of non-limiting example.

Figure 1 shows an exploded view of the new machine, showing the separate parts, while figures 2 and 3 schematically show the operation of the machine in two configurations with different axial coupling lengths (H1, H2).

The new hydraulic machine (1) comprises a casing or containment body, not shown in the figures, identifying at least one chamber or volume (2) through which a working fluid, for example gas, vapor or liquid, passes.

The new machine (1) includes, housed inside said chamber or volume (2), at least two main rotors (A, B), rotating in a synchronized way around axes (Xa, Xb) parallel to each other.

Said main rotors (A, B) are of the gear or lobe type, ie each comprise at least one wheel provided with teeth (A1, B1) or lobes, and where said rotors (A, B) are mutually engaged.

Said main rotors (A, B) are each connected to a shaft (3, 4) suitable for transmitting the rotary motion of said rotors (A, B).

In particular, the new machine can be used as a pump, transmitting energy to the fluid, or as a motor, absorbing energy from the fluid.

The new machine (1) also includes, housed inside said casing, at least two additional complementary members (C, D), each coupled to a relative said main rotor (A, B).

Each of said complementary members (C, D) comprises an external rotation surface (C2, D2), for example substantially cylindrical, and an axial seat (C1, D1) of dimensions and shape corresponding to the shape of the relative main rotor (A, B) and suitable for the insertion in axial direction (Xa, Xb) of said main rotor (A, B) in all or part of its axial length (Ha, Hb).

Each of said complementary members (C, D) rotates integrally with the relative main rotor (A, B), said main rotor (A, B) being preferably always engaged in said seat (C1, D1) of the relative complementary member (C, D ) for at least part (Hi) of its axial length (Ha, Hb).

Said main rotors (A, B) are free to translate with respect to said chamber (2) and to said complementary members (C, D), translating into the relative seats (C1, D1) of said complementary members (C, D) themselves, in so as to vary in axial length their wet work surface (Sa, Sb), that is the work surface (Sa1, Sb1) which protrudes from said complementary members (C, D) and which is therefore affected by the transit of the fluid.

Said complementary members (C, D) have the function of filling inside said chamber (2) the volume portions surrounding the relative main rotor (A, B) in correspondence with the non-wetted work surface (Sa2, Sb2), reducing the wet working surface (Sa1, Sb1) of the relevant main rotor (A, B).

The new machine (1) also comprises, housed inside said casing, further filling members or elements (E, F), suitable for filling the volumes of said chamber (2) above and below said main rotors (A, B), preferably incorporating said complementary members (C, D), to correctly convey the fluid flow, preventing it from being diverted into free spaces above or below the main rotors (A, B) themselves.

In the preferred solution, the new machine (1) comprises at least two of said filling elements (E, F), an upper element (E) and a lower element (F) with respect to said main rotors (A, B), of shape such as to guarantee the seal on said casing or containment body.

Said filling elements (E, F) are able to translate correspondingly to said main rotors (A, B), preferably without rotating, so as to reduce or increase the volume of said chamber (2) in axial length.

In particular, said upper filling element (E) translates integrally to one of said main rotors (B), while said lower filling element (F) translates integrally to the second of said main rotors (A).

Each of said upper (E) and lower (F) filling elements comprises a part (E1, F1) substantially aligned with the relative main rotor (B, A) and a seat (E2, F2) in which the relative complementary member (C, D) of the other main rotor (A, B).

As exemplified in Figure 2a, the new machine therefore comprises said two main rotors (A, B) which can be coupled together for a maximum axial length (H1), where the wet working surface (Sa1, Sb1) is maximum. In this configuration, said upper (E) and lower (F) filling elements are at the maximum distance from each other, while said main rotors (A, B) are exposed from the relative seats (C1, D1) of said complementary members (C , D) for a maximum axial length.

By translating said main rotors (A, B) with respect to the relative complementary member (C, D), as shown in figure 2b, said main rotors (A, B) are inserted for part of their axial length in the relative seats (C1, D1), thus reducing the axial length (H2) of mutual coupling and also the wet work surface (Sa1, Sb1), i.e. the work surface that is exposed.

By translating said main rotors (A, B) also one or both of said filling elements (E, F) are correspondingly translated, thus reducing overall the volume of said chamber (2).

In conclusion, the flow rate of fluid is substantially varied by varying the geometry of the system.

It can also be envisaged that the new machine (1) comprises gears or means external to said chamber (2), suitable for maintaining synchronism in the rotation of said main rotors (A, B) even if said rotors (A, B ) are not directly involved with each other.

These are the schematic modalities sufficient for the skilled person to realize the invention, consequently, in concrete application there may be variations without prejudice to the substance of the innovative concept.

Therefore, with reference to the above description and the attached tables, the following claims are expressed.

Claims (11)

CLAIMS 1. Hydraulic machine (1) comprising a casing or containment body identifying at least one chamber or volume (2) through which a working fluid passes, and at least two main rotors (A, B) housed inside said chamber (2 ), of the type with gears or lobes and reciprocally engaged, characterized by the fact that one or both of said main rotors (A, B) are able to translate relative to their axes (Xa, Xb) to vary the axial length (H) of reciprocal coupling affected by the transit of the fluid, ie the work surface (Sa1, Sb1) which is exposed, so that the flow rate of fluid varies as the geometry of the system varies. 2. Hydraulic machine (1), as per claim 1, characterized in that it also comprises at least two additional complementary members (C, D), each coupled to a relative main rotor (A, B), and rotating integrally thereto, each of said complementary members (C, D) comprising an external rotation surface (C2, D2) and a seat (C1, D1) of dimensions and shape corresponding to the shape of the relative main rotor (A, B) and suitable for insertion into axial direction (Xa, Xb) of said main rotor (A, B) in whole or in part its axial length (Ha, Hb) 3. Hydraulic machine (1), as per claims 1, 2, characterized in that each of said main rotors (A, B) is always engaged in said seat (C1, D1) of the relative complementary member (C, D) for at least a part (Hi) of its axial length (Ha, Hb). 4. Hydraulic machine (1), as per claims 1, 2, 3, characterized in that it also comprises at least further movable filling members or elements (E, F), suitable for filling the volumes of said chamber (2) above and below said main rotors (A, B), to correctly convey the fluid flow, preventing it from being deflected above or below the main rotors (A, B) themselves. 5. Hydraulic machine (1), as per claim 4, characterized in that it comprises at least two of said filling elements (E, F), an upper element (E) and a lower element (F) with respect to said main rotors ( A, B), of such shape as to guarantee the seal on said casing or containment body. 6. Hydraulic machine (1), as per claim 5, characterized in that said upper filling element (E) translates integrally to one of said main rotors (B), while said lower filling element (F) translates integrally to the second of said main rotors (A), consequently increasing or reducing the free volume of said chamber (2). 7. Hydraulic machine (1), as per claims 5, 6, characterized in that each of said upper and lower filling elements (E, F) comprises a solid part (E1, F1) axially aligned to the relative main rotor (B , A) and a seat (E2, F2) in which said complementary member (C, D) of the other main rotor (A, B) is housed and freely rotating. 8. Hydraulic machine (1), as per the preceding claims, characterized in that said main rotors (A, B) rotate in a synchronized way around axes (Xa, Xb) which are parallel to each other. 9. Hydraulic machine (1), as per the preceding claims, characterized in that said main rotors (A, B) are each connected to a shaft (3, 4) for transmitting the motion of said rotors (A, B). 10. Hydraulic machine (1), as per claim 9, characterized in that said machine can be used as a pump, transmitting energy to said fluid, or as a motor, absorbing energy from said fluid. 11. Hydraulic machine (1), as per the preceding claims, characterized in that it comprises gears or means external to said chamber (2) able to maintain synchronism in the rotation between said main rotors (A, B).