Turbo-compressor

Abstract

A turbo-compressor, comprises: a turbine (6) positioned in a casing (2) so as to be able to rotate with respect to the casing (2), wherein the turbine (6) is bladeless and comprises a body (15) and a helical duct (16) obtained inside the body (15) and developing in loops from a turbine inlet (19) to at least one turbine outlet (20); an electric motor (4) provided with a rotating shaft (7) mounted possibly in the casing (2) so as to be able to rotate with respect to the casing (2) about an its own main axis (X-X); a compressor (5) mounted in the casing (2) and connected to the rotating shaft (7). The turbine (6) is mounted integral with the rotating shaft (7) or the turbine (6) and the rotating shaft (7) are mechanically connected to each other via a speed reducer / multiplier (42) or the compressor (6) and the rotating shaft (7) are mechanically connected to each other via a speed reducer / multiplier (42). The turbine (6), the compressor (5), possibly the electric motor (4) and the rotating shaft (7) are all enclosed in the casing (2) and the turbine (6) and the compressor (5) are separate elements.

Description

[0001] DESCRIPTION connected to patent application for INDUSTRIAL INVENTION entitled: “Turbo-compressor”

[0002] On behalf: SF ENERGY SRL of Italian nationality based in LEGNANO (Ml)

[0003] Field of the invention

[0004] The present invention has as its object a turbo-compressor and an apparatus comprising this turbo-compressor. Preferably but not exclusively, the present invention is in the area of turbo-compressors used in the field of energy conversion apparatus, e.g., apparatus configured to realize refrigeration cycles / heat pumps.

[0005] Background art

[0006] Compact turbo-compressors, enclosed in a single casing and provided with bladefree impellers are known. For example, document US6368078B1 shows a turbo-compressor used in internal combustion engines that comprises a turbine and a compressor connected by a shaft, each one without blades (bladeless) and formed by a plurality of discs. Document US6726443 shows a micro-machine comprising a compressor and a turbine with a structure similar to the one of the preceding document. US11525394 shows instead a turbine and a compressor that both have blades and are mounted on a common shaft. It is also known the document WO2023 / 187674 in the name of the same Applicant which shows a bladeless turbine on which are mounted blades of a compressor.

[0007] Object of the invention

[0008] In this field, the Applicant has aimed at exploiting the principle of turbomachines without blades to propose a turbo-compressor more compact and efficient than those of the known technique and employable in different areas for energy conversion.

[0009] The Applicant has specifically aimed at proposing a structurally simple and then also relatively cheap and reliable turbo-compressor. The Applicant has aimed at proposing a turbo-compressor characterized by a facilitated and simplified maintenance.

[0010] The Applicant has aimed at proposing a turbo-compressor with a turbine that is replaceable and removable in a quick manner.

[0011] The Applicant has aimed at proposing a modular and versatile turbo-compressor. The Applicant has also aimed at proposing a compact turbo-compressor and then easily positionable in apparatus wherein it is adopted, for example in energy conversion apparatus, particularly in apparatus configured to realize refrigeration cycles / heat pumps.

[0012] Summary of the invention

[0013] The Applicant has found that such objectives and purposes can be achieved by realizing a turbo-compressor in accordance with the present invention, of the type claimed in the annexed claims and / or described in the following aspects.

[0014] In accordance with a first aspect, the present invention is related to a turbocompressor, comprising: a casing; a turbine mounted in the casing so as to be able to rotate with respect to the casing about an axis of rotation; wherein the turbine is bladeless and comprises at least one body and at least one helical duct obtained inside the body and developing in loops from at least one turbine inlet to at least one turbine outlet; wherein a distance of the helical duct from the axis of rotation decreases from said at least one turbine inlet to said at least one turbine outlet; an electric motor provided with a rotating shaft so as to be able to rotate with respect to the casing about an its own main axis, the electric motor being optionally mounted in the casing; a compressor mounted in the casing and connected to said rotating shaft; wherein the turbine is mounted integral with the rotating shaft or wherein the turbine and the rotating shaft are mechanically connected to each other via a speed reducer / multiplier or wherein the compressor is mounted integral with the rotating shaft or wherein the compressor and the rotating shaft are mechanically connected to each other via a speed reducer / multiplier. The turbine, the compressor, possibly the electric motor and the rotating shaft are all enclosed in the casing and the turbine and the compressor are separate elements; optionally the turbine is axially spaced from the compressor. In accordance with a second aspect is related to an apparatus, for example a refrigerating apparatus / heat pump, comprising a turbo-compressor according to the preceding first aspect and / or according to one or more of the aspects described below.

[0015] In the present description and in the annexed claims, with the term “blade”, it is generally intended an assembly of elements or an opportunely shaped element that rotate / s with the rotor and that interact / s with the working fluid to transform the fluid energy into mechanical energy of rotor rotation or vice versa. A blade can comprise blades, vanes, lobes, the profile of a screw, etc. and a turbine is bladeless is therefore devoid of such elements.

[0016] The Applicant has verified that the compactness of the turbo-compressor according to the invention allows its easy installation in apparatus of different type and size.

[0017] The Applicant has also verified that the turbo-compressor according to the invention results, besides being compact, also structurally simple therefore reliable and relatively cheap. In particular, the absence of blades in the turbine, makes it more robust and reliable and thus makes the turbo-compressor as a whole more reliable. The Applicant has further verified that the turbo-compressor according to the invention allows to improve the efficiency of apparatus wherein it is installed. The Applicant has in particular verified that the adoption of the turbo-compressor according to the invention in a refrigerating apparatus allows to reduce consumption and / or increase the cooling power (or heat generation if used as a heat pump), i.e., to improve the efficiency. This results even more impactful in light of the fact that in the expansion steps within refrigeration cycles / heat pumps is present a two-phase fluid (liquid + vapor). This type of fluid results difficult to direct in bladed channels, as its density varies as much as thousand times between the liquid phase and the vapor phase, and analogously the centrifugal forces acting on each component. Therefore, the velocity triangles on which the optimization of the bladed turbines is based, vary enormously between liquid and vapor, making the turbine inefficient. Furthermore, from the point of view of mechanical wear, each blade requires to be oversized to resist the impact of the liquid component, and, where this is not possible, this results in breakage. The Applicant has further verified that, in the configuration with speed reducer / multiplier, it is possible to run compressor and turbine at different and optimized RPMs.

[0018] Further aspects according to the present invention are described below.

[0019] In an aspect, the casing has a cylindrical or substantially cylindrical outer outline.

[0020] In an aspect, the main axis of the rotating shaft and the axis of rotation coincide.

[0021] In an aspect, the turbine is coaxial to the rotating shaft.

[0022] In an aspect, the turbo-compressor comprises a plurality of turbines, optionally two turbines are placed symmetrically, optionally on opposite sides with respect to the compressor, or are arranged in series.

[0023] In an aspect, the compressor is mounted integral with the rotating shaft or wherein the compressor and the rotating shaft are mechanically connected to each other via a speed reducer / multiplier.

[0024] In an aspect, the compressor is of the piston or scroll or centrifugal (impeller) or screw, or twin rotary, or rotary type.

[0025] In an aspect, the compressor comprises a piston and a connecting rod and a portion of the rotating shaft defines a crank.

[0026] In an aspect, the compressor comprises a cylinder housing the piston slidingly and the connecting rod is pivotally coupled to the cylinder and to the crank.

[0027] In an aspect, the portion of the rotating shaft defining the crank is located between the electric motor and the turbine.

[0028] In an aspect, the speed reducer / multiplier is configured so that the turbine rotates at lower rpm with respect to the compressor.

[0029] In an aspect, the speed reducer / multiplier is configured so that the turbine rotates at higher rpm with respect to the compressor.

[0030] In an aspect, the scroll compressor comprises an impeller comprising a cochlea spiral and a statoric part comprising a fixed cochlea spiral coupled to the cochlea spiral of the impeller.

[0031] In an aspect, the rotating shaft is supported in the casing via two supporting groups, optionally bearings or bushings or magnetic bearings, axially spaced from each other; wherein the turbine is located between the two supporting groups or wherein the turbine is positioned cantilevered with respect to the two supporting groups; wherein the compressor is positioned between the two supporting groups or wherein the compressor is positioned cantilevered with respect to the two supporting groups. In an aspect, the compressor is mounted at a terminal end of the rotating shaft.

[0032] In an aspect, the body of the turbine has tapered outline from a first axial end to a second axial end.

[0033] In an aspect, the body of the turbine has a substantially conical part tapering toward the second axial end.

[0034] In an aspect, at least one part of the body of the turbine is realized with a partially hollow structure, for example honeycomb-like, to lighten it and / or to balance it and / or to balance the entire turbomachine by replacing the balancing ring.

[0035] In an aspect, the body has a plurality of helical ducts.

[0036] In an aspect, one or more of said helical ducts can have variable section along a respective extension.

[0037] In an aspect, one or more of said helical ducts can divide into two or more helical ducts.

[0038] In an aspect, one or more of said helical ducts can divide into two or more helical ducts and be configured to separate the fluid passing in two distinct steps or volumes.

[0039] In an aspect, two or more of said helical ducts can combine into a single resulting helical duct.

[0040] In an aspect, one or more of said helical ducts completes a full rotation about the main axis.

[0041] In an aspect, one or more of said helical ducts does not complete a full rotation about the main axis.

[0042] In an aspect, said at least one turbine inlet is radial, axial, tangent to a circle concentric to the axis of rotation, skewed with respect to the axis of rotation.

[0043] In an aspect, said at least one turbine inlet comprises a plurality of turbine inlets formed on a radially peripheral portion of the body.

[0044] In an aspect, said radially peripheral portion of the body is a cylindrical surface coaxial to the axis of rotation.

[0045] In an aspect, the turbine inlets are arranged along a circular path defined on the radially peripheral portion of the body. In an aspect, said at least one turbine outlet is located on the second axial end of the body.

[0046] In an aspect, said at least one inlet and / or said at least one outlet can be positioned on axial areas of the body placed between the first and the second axial end of the body.

[0047] In an aspect, said at least one outlet is axial or radial or tangent to a circle concentric to the axis of rotation, oriented or skewed with respect to the axis of rotation.

[0048] In an aspect, a maximum diameter of the body of the turbine is greater than, less than or equal to a maximum diameter of the compressor.

[0049] In an aspect, the casing contains a first annular chamber arranged about the radially peripheral portion of the body, the first annular chamber being connected to an inlet in the casing.

[0050] In an aspect, the first annular chamber is coupled to a respective first axial section of the casing.

[0051] In an aspect, the first axial section has annular shape.

[0052] In an aspect, the first axial section is separable from the rest of the casing.

[0053] In an aspect, the first axial section is located in a radially internal position with respect to an outer wall of the casing.

[0054] In an aspect, the first annular chamber is located between an outer wall of the casing and the body.

[0055] In an aspect, inlet vanes (IGV - inlet guide vanes) are arranged in the first annular chamber.

[0056] In an aspect, said inlet vanes are movable and adjustable to regulate a flow to the turbine inlets and manage variable loads.

[0057] In an aspect, said inlet vanes are movable and adjustable to manage different fluid typologies, different flow rates and, in general, to vary the turbo-compressor application.

[0058] In an aspect, an inlet valve is operatively coupled to the inlet in the casing.

[0059] In an aspect, the inlet valve is a partializing valve configured to regulate a flow to the turbine inlets.

[0060] In an aspect, a pair of first walls supported in the casing is arranged about the radially peripheral portion of the body; the first walls face each other and delimit the first annular chamber. In an aspect, the first wall closest to the second axial end of the body is arranged about the substantially conical part of the body so that the fluid pressure in the first annular chamber acts on a portion of the substantially conical part and axially balances, at least in part, an axial thrust generated by the fluid inside the helical duct.

[0061] In an aspect, each of the first walls lies in a plane orthogonal to the axis of rotation. In an aspect, each of the first walls is connected and supported by the first axial section of the casing.

[0062] In an aspect, each of the first walls comprises a sealing element (annular gasket) located at its own radially inner circular peripheral edge and located at the radially peripheral portion of the body.

[0063] In an aspect, the sealing element is axially or radially arranged between the peripheral edge and the radially peripheral portion.

[0064] In an aspect, each of said first walls extends from the outer wall of the casing up to its own radially inner circular peripheral edge.

[0065] In a different aspect, a first cylindrical wall bears the pair of first walls, is radially spaced from the outer wall of the casing and is connected to said outer wall of the casing from first radial elements.

[0066] In an aspect, the pair of first walls is divided into angular sectors juxtaposed with each other.

[0067] In an aspect, the first cylindrical wall is divided into angular sectors, each bearing an angular sector of the pair of first walls and comprising one of the first radial elements.

[0068] In an aspect, the casing delimits internally a volume for housing the turbine, of the eventual electric motor and of the shaft.

[0069] In an aspect, the casing comprises a removable portion configured to allow the access to the inner volume of the casing when disassembled.

[0070] In an aspect, the casing comprises a base body, the removable portion being removably connected to the base body and configured to close the inner volume of the casing when connected to the base body.

[0071] In an aspect, the connection between the removable portion and the base body is hermetic. In an aspect, the removable portion is defined by a portion or upper half of the casing and the base body is defined by a portion or lower half of the casing.

[0072] In an aspect, a septum divides said volume from a housing of the compressor, wherein the housing is inside the casing.

[0073] In an aspect, the septum bears a supporting group for the rotating shaft.

[0074] In an aspect, channels or openings connect among them areas of said volume separated by the pair of first walls.

[0075] In an aspect, the volume is void or contains a cooling oil or gas.

[0076] In an aspect, the volume is in fluid communication with a cooling circuit or with a cooling liquid recovery circuit.

[0077] In an aspect, a pump for the cooling oil or gas is mounted on the rotating shaft.

[0078] In an aspect, the channels are delimited in ducts connected to the two first walls of the pair and passing through the first annular chamber.

[0079] In an aspect, the openings are delimited among the first radial elements.

[0080] In an aspect, said at least one turbine inlet comprises various series of turbine inlets formed on radially peripheral portions of the body; each series comprising a plurality of inlets arranged on a respective radially peripheral portion of the body and along a respective circular path; the series being axially offset to each other.

[0081] In an aspect, each series is part of at least one helical duct so as to form multiple stages of turbines.

[0082] In an aspect, each series is coupled to a respective first annular chamber.

[0083] The Applicant has verified that this structure with various series of inlets allows to work with variable loads, opening / closing the power supply of one or more series.

[0084] In an aspect, the casing contains a second annular chamber arranged about the second axial end of the body, the second annular chamber being in fluid communication with said at least one turbine outlet and being connected to an outlet from the casing.

[0085] In an aspect, the second annular chamber is coupled to a respective second axial section of the casing.

[0086] In an aspect, the second axial section has annular shape.

[0087] In an aspect, the second axial section is separable from the rest of the casing.

[0088] In an aspect, the second axial section is located in a radially inner position with respect to an outer wall of the casing. In an aspect, the second annular chamber is located between an outer wall of the casing and the body.

[0089] In an aspect, the rotating shaft delimits an inner channel, optionally a plurality of inner channels, having an end in fluid communication with said at least one turbine outlet and an opposite end connected to an outlet from the casing.

[0090] In an aspect, the rotating shaft delimits internally channels for adduction of bearings oil.

[0091] In an aspect, the inner channel is parallel to the axis of rotation.

[0092] In an aspect, the second annular chamber is located between an outer wall of the casing and the body.

[0093] In an aspect, a pair of second walls supported in the casing are arranged about the second axial end of the body; the second walls face each other and delimit the second annular chamber.

[0094] In an aspect, each of the second walls lies in a plane orthogonal to the axis of rotation.

[0095] In an aspect, each of the second walls is connected and supported by the second axial section of the casing.

[0096] In an aspect, the first and the second axial section of the casing form a unique body. In an aspect, each of the second walls comprises a sealing element (gasket) located at its own radially inner circular peripheral edge and located at the second axial end of the body.

[0097] In an aspect, the circular peripheral edge of one of the second walls is placed next to the second axial end of the body while the circular peripheral edge of the other of the second walls is placed next to the second axial end of the body or to the rotating shaft.

[0098] In an aspect, each of said second walls extends from the outer wall of the casing up to its radially inner circular peripheral edge.

[0099] In a different aspect, a second cylindrical wall bears the pair of second walls, is radially spaced from the outer wall of the casing and is connected to said outer wall of the casing by second radial elements.

[0100] In an aspect, the pair of second walls is divided into angular sectors juxtaposed with each other. In an aspect, the second cylindrical wall is divided in angular sectors, each bearing an angular sector of the pair of second walls and comprising one of the second radial elements.

[0101] In an aspect, channels or openings connect among them areas of said volume separated by the pair of second walls.

[0102] In an aspect, the channels are delimited in ducts connected to the two second walls of the pair and passing through the second annular chamber.

[0103] In an aspect, the openings are delimited among the second radial elements.

[0104] The Applicant has verified that the openings or passages ensure an effective cooling of parts inside the casing.

[0105] The Applicant has verified that division into angular sectors allows to easily assemble or disassemble the turbo-compressor.

[0106] In an aspect, at least one balancing mass is integral with the rotating shaft and is eccentric with respect to the axis of rotation. The balancing mass is configured to balance imbalances due to the compressor.

[0107] In an aspect, the balancing mass is keyed on the rotating shaft.

[0108] In an aspect, the balancing mass is integral to the body of the turbine or is embedded in the body of the turbine.

[0109] In an aspect, the balancing mass is the turbine itself.

[0110] The Applicant has verified that the same body of the turbine can be realized or used to bear the balancing mass or be the balancing mass itself, eliminating the need for an additional element to be mounted on the shaft in an axial position other than the one of the turbine and thus allowing to reduce the axial dimensions of the rotating shaft and of the entire turbo-compressor.

[0111] To this purpose, the turbine itself can be realized with portions with different cavities or different densities, for example honeycomb-like.

[0112] The Applicant has verified that this balancing mass is useful / necessary if the compressor is of the scroll type since the scroll impeller is eccentric with respect to the main axis.

[0113] In an aspect, the body of the turbine is mounted pivotably on the rotating shaft, optionally via bearings or bushings or magnetic bearings, and the speed reducer / multiplier comprises a gear assembly placed about to the rotating shaft.

[0114] In an aspect, the speed reducer / multiplier is of epicycloidal or planetary type. In an aspect, the body turbine is mounted integral to a respective turbine shaft, the compressor is mounted integral to a respective compressor shaft, wherein the rotating shaft is the turbine shaft or the rotating shaft is the compressor shaft; the speed reducer / multiplier is operatively interposed between the turbine shaft and the compressor shaft.

[0115] In an aspect, the turbo-compressor comprises a diffuser element connected to the casing and associated to the turbine outlet and / or to the inner channel of the rotating shaft.

[0116] In an aspect, the diffuser element is configured to direct the fluid in outlet from the inner channel and / or from the turbine outlet.

[0117] In an aspect, the refrigerating apparatus comprises: at least one condenser; at least one evaporator; at least one turbo-compressor according to one or more of the preceding aspects; ducts connecting said at least one condenser, said at least one evaporator and said at least one turbo-compressor for forming a refrigerating circuit. The ducts connect said at least one condenser and said at least one evaporator to said at least one turbo-compressor so as to compress a working fluid circulating in the refrigerating circuit before it enters said at least one condenser and to expand said working fluid before it enters said at least one evaporator.

[0118] Further features and advantages will appear more from the detailed description of preferred, but not exclusive, embodiments of a turbo-compressor and of a refrigerating apparatus in accordance with the present invention.

[0119] Short description of the drawings

[0120] This description will be indicated below with reference to the attached drawings, provided for illustrative purposes only and, therefore, not limiting, in which:

[0121] - figure 1 is a view in a longitudinal section of a turbo-compressor according to the present invention;

[0122] - figure 1A shows an enlarged part of figure 1 ;

[0123] - figure 2 is a sectional view of a variant of the turbo-compressor of figure 1 ;

[0124] - figure 3 is a front view of a turbine part of the turbo-compressor of the preceding figures;

[0125] - figure 4 shows a cross section of an element of the turbo-compressor of figure 1 ; - figure 5 shows a cross section of another element of the turbo-compressor of figure 1 and figure 2;

[0126] - figures 6 to 9 show each respective variants of the turbine of the turbocompressor according to the present invention;

[0127] - figure 10 shows a portion of the turbo-compressor according to the present invention according to a variant provided with a speed increaser / reducer;

[0128] - figure 11 shows a different embodiment of the turbo-compressor according to the present invention;

[0129] - figure 12 and 13 show further schemes of the turbo-compressor according to the present invention;

[0130] - figure 14 shows schematically a refrigerating apparatus provided with a turbo-compressor according to the invention;

[0131] - figure 15 shows a refrigerating cycle carried out by the apparatus of figure 14 compared with a traditional refrigerating cycle;

[0132] - figure 16 shows a portion of a further variant of the turbo-compressor according to the invention;

[0133] - figure 17 is a sectional view of a variant of the turbo-compressor according to the present invention;

[0134] - figure 18 shows a scheme of the turbo-compressor according to the present invention.

[0135] Detailed description of preferred embodiments of the invention

[0136] With reference to the attached figures, with 1 has been overall indicated a turbocompressor according to the present invention.

[0137] The turbo-compressor 1 comprises a casing 2 defined by an outer wall 3 of substantially cylindrical outline within which are housed an electric motor 4, which may be of the type per se known and therefore has not been described in detail here, a compressor 5 and a turbine 6.

[0138] The electric motor 4 is provided with a rotating shaft 7 mounted in the casing 2 so as to be able to rotate with respect to the casing 2 about an its own main axis X-X, i.e. is for example supported by supporting groups, as bearings or bushings or magnetic bearings. In figures 1 and 2, the rotating shaft 7 is coaxial to the outer wall 3 of the casing 2. The electric motor 4 is placed near an end of the casing 2 and the rotating shaft 7 extends from the electric motor 4 to an opposite end of the casing 2.

[0139] The compressor s of figures 1 and 2 is of the scroll type, i.e. comprises an impeller

[0140] 8 comprising a disc on whose face is defined a cochlea spiral 9 that delimits a cochlea path. The disc of the compressor scroll is not coaxial to the turbine 6. A statoric part 10 comprising a fixed cochlea spiral 11 is coupled to the cochlea spiral

[0141] 9 of the impeller 8. Figures 1 and 2 show the scroll compressor 5 in longitudinal section placed on terminal end of the rotating shaft 7. In particular, the impeller 8 of the compressor 5 is fixed to the terminal end of the rotating shaft 7 so as to rotate integrally with said rotating shaft 7.

[0142] The impeller 8 of the scroll compressor is not symmetrical with respect to the main axis X-X of the rotating shaft 7 so the turbo-compressor 1 comprises a balancing disc 12 keyed on the rotating shaft 7 and integral to said rotating shaft 7. This balancing disc 12 is provided with a balancing mass 13 eccentric with respect to the main axis X-X. In figures 1 and 2 the balancing disc 12 is next to the electric motor 4.

[0143] In an embodiment, the relative position between the compressor 5 and the turbine 6 is chosen so as to balance its axial thrust so as to lighten the load to which the bearings 40, 41 that support the turbine are subjected. Furthermore, the balancing of the axial thrust allows to reduce, or better control, the vibrations of the system. The compressor 5 and the turbine 6 are, in particular, arranged at sides opposite to each other of the rotating shaft 7, as schematically shown in figure 18.

[0144] The turbine 6 is positioned in the casing 2 so as to be able to rotate with respect to the casing 3 about an axis of rotation. In figures 1 and 2, the turbine 6 comprises a body 15 keyed on the rotating shaft 7 so as to rotate integral with it about the main axis X-X, that therefore coincides with the axis of rotation of the turbine 6. The body 15 can be connected to the rotating shaft 7 by interference, screwing, by means of a crown with toothing 43 or a Hirth joint.

[0145] The turbine 6 is of the bladeless type or “bladeless” and comprises one or more helical ducts 16 formed internally to the body 15. In figures 1 and 2 for the sake of clarity it has been schematically represented only a helical duct 16. The body 15 comprises a radially peripheral portion provided with a cylindrical surface 17 coaxial to the axis of rotation located near a first axial end and a substantially conical part 18 that tapers from the portion with the cylindrical surface 17 to a second axial end opposite to the first axial end. The substantially conical part 18 has a concave outer surface. The body 15 of the turbine 6 has thus tapered outline from the first axial end to the second axial end. It is not excluded, however, that the substantially conical part 18 may have a convex outer surface.

[0146] The helical duct 16 develops in loops from a plurality of turbine inlets 19 positioned on the cylindrical surface 17 to a turbine outlet 20, or multiple outlets turbine 20, located on a face of the second axial end (figure 1 ) or anyway in correspondence of the second axial end (figure 2).

[0147] In detail, one or more of said helical ducts can divide in two or more helical ducts. Then, a turbine inlet 19 can be connected to a plurality of turbine outlets 20 through a helical duct that divides in multiple helical ducts among the inlet and the outlets.

[0148] In particular, a helical duct can divide in two helical ducts so as to separate the fluid passing into two distinct volumes. Advantageously, the division of a duct into two distinct ducts allows to use the centrifugal force to separate two phases of the passing fluid having different density. For example, it is possible to separate the passing fluid in a helical duct by directing in one duct a gaseous component present in the fluid, and in the other duct a liquid component of the fluid.

[0149] However, it is not excluded that two or more of said helical ducts can combine in a single resulting helical duct. Then, two or more turbine inlets 19 can be connected to a unique turbine outlet 20 by means of helical ducts that join together.

[0150] The turbine inlets 19 are arranged along a circular path defined on the radially peripheral portion of the body 15. A distance of the helical duct 16 from the axis of rotation decreases from the turbine inlets 19 to the turbine outlet 20.

[0151] In an embodiment, one or more of said helical ducts can have variable section along a respective extension. One or more of the plurality of helical ducts can then have a variable section between the inlet and the outlet. For example, the duct can have an inlet section larger with respect to an outlet section.

[0152] In figure 1 , the turbine outlet 20 is axially oriented. It is not excluded however that the outlet can be radial or tangent to a circle concentric to the axis of rotation or skewed with respect to the axis of rotation. In the variant of figure 2, the turbine outlet 20 is connected to an inner channel 21 of the rotating shaft 7. The inner channel 21 is parallel to the main axis X-X and has an end in fluid communication with the turbine outlet 20 and an opposite end connected to an outlet 22 from the casing 2. The inner channel 21 can have cross sections of different shapes. The internal channels 21 can also be a plurality. The rotating shaft 7 can also delimit internally channels 63 for adduction of bearings oil, as for example in figure 10.

[0153] As shown in figure 3, the turbine inlets 19 are oriented along directions tangent to circles concentric to the axis of rotation of the body 15. Furthermore, the ducts 16 departing from each of the turbine inlets 19 can converge all into a single helical duct 16 ending in the unique turbine outlet 20.

[0154] The body 15 of the turbine 6 can furthermore be realized with a partially hollow structure, for example honeycomb-like, to lighten it and / or to balance it.

[0155] For example, the turbine 6 is of the type shown in the application WO2023 / 187674 in the name of the same Applicant.

[0156] With reference to figure 1 , an inlet 23 is obtained through the casing 2 and is in fluid communication with the turbine inlets 19 according to what is detailed below.

[0157] The turbo-compressor 1 comprises a first axial section 24 of annular shape, coaxial to the main axis X-X and located in a radially inner position with respect to the outer wall 3 of the casing 2. The first axial section 24 is separable from the rest of the casing 3.

[0158] From a radially inner surface of the first axial section 24 and toward the rotating shaft 7 develop two first walls 25a, 25b that lie in planes orthogonal to the main axis X-X, are reciprocally and axially spaced with each other and are arranged about the radially peripheral portion of the body 15. In particular, each of the first walls 25a, 25b is a disc with a central hole and, at its own radially inner circular peripheral edge 26 (that delimits the central hole, figure 5), has a sealing element 27 (annular gasket). The body 15 is placed in the aforementioned central hole. The radially inner circular peripheral edges 26 and the relative sealing elements 27 are placed at the cylindrical surface 17 of the body 15 and on sides opposite with respect to the turbine inlets 19.

[0159] Therefore, the first walls 25a, 25b face each other and delimit, between them and together with the radially inner surface of the first axial section 24, a first annular chamber 28 arranged about the radially peripheral portion of the body 15 and about to the turbine inlets 19. The inlet 23 obtained through the casing 2 passes through the first axial section 24, so the first annular chamber 28 is connected to said inlet 23.

[0160] In the embodiment of figures 1 and 1 A, inlet vanes 29 (IGV - inlet guide vanes) are arranged in the first annular chamber 28. The inlet vanes 29 are positioned about the cylindrical surface 17 of the body 15. Each blade of inlet 29 is constrained to one or to both the first walls 25a, 25b so as to be able to rotate about a respective axis Y-Y parallel to the axis of rotation. The inlet vanes 29 are furthermore connected to a mechanism and to an actuator, not shown, configured to vary an angular position of them, so as to be able to regulate a flow to the turbine inlets 19 and 20 and manage variable loads. The possibility to vary an angular position of the blades also allows to use the turbo-compressor for applications different among them, with different fluids or flow rates. For example, the turbo-compressor can be used with propane for one application and with butane for another application.

[0161] In embodiment variants, the turbo-compressor 1 comprises an inlet partializing valve, not shown, operatively coupled to the inlet 23 to regulate a flow to the turbine inlets 19 and optimize the operation with variable loads.

[0162] Ducts 30, visible in figure 5, connect the two first walls 25a, 25b and axially pass through the first annular chamber 28, so as to put in fluid communication zones of a volume 31 inside the casing 2 that are separated by the pair of first walls 25a, 25b. These ducts 30 are also visible in the embodiment variant of figure 2. In fact, the casing 2 internally delimits the volume 31 for housing the turbine 6, the electric motor 4 and the shaft 7. This volume 31 is void or can be in connection with a cooling circuit (not shown) that determines the circulation of a cooling oil or gas in the volume 31 .

[0163] The volume can also be in connection with a cooling liquid recovery circuit.

[0164] The ducts 30 allow the passage of the cooling oil or gas. The pump for the cooling oil or gas can be for example too mounted on the rotating shaft 7.

[0165] A septum 100 located inside the casing 2 divides the aforementioned volume 31 from a housing 110 for the impeller 8 of the compressor 5. The septum 100 bears a supporting group 50 (for example a bearing) for the rotating shaft 7.

[0166] In the embodiment of figure 1 and 1A, the casing 2 delimits a second annular chamber 32 arranged about the second axial end of the body 15, such that in said second annular chamber 32 opens the turbine outlet 20. The second annular chamber 32 is furthermore connected to an outlet 33 by the casing 2.

[0167] The second annular chamber 32 is delimited by a pair of second walls 34a, 34b supported in the casing 2 and each lying in a plane orthogonal to the main axis X- X. The second walls 34a, 34b are arranged about the second axial end of the body 15. The second walls 34a, 34b face each other and delimit the second annular chamber 32.

[0168] Each of the second walls 34a, 34b comprises a sealing element 35 (gasket) located at its own radially inner circular peripheral edge 36 and at the second axial end of the body 15. In particular, according to the embodiment of figures 1 and 1A, the circular radially inner peripheral edge 36 of a second wall 34a of the pair surrounds the rotating shaft 7 while the circular radially inner peripheral edge 36 of the other second wall 34b is located about the substantially conical part 18 of the body 15. The second walls 34a, 34b, are born by a second cylindrical wall 37 that is radially spaced from the outer wall 3 of the casing 2 and is connected to a second axial section 38 via second radial elements 37a, better visible in figure 4. The second axial section 38 is fixed with respect to said outer wall 3 of the casing 2. More in detail, the second axial section 38 is of annular shape, coaxial to the main axis X-X, is located in a position radially inner with respect to the outer wall 3 of the casing 2 and from it radially extend the aforementioned radial elements 37a. The second axial section 38 is separable from the rest of the casing. As visible in figure 4, the radial elements 37a delimit among them wide openings 39 so there is no need to use the ducts 30. Furthermore, through one or more of the annular elements a passage is formed connected to the outlet 33 (figure 4). The first and the second axial section 24, 38 can also be realized as a unique body.

[0169] In other embodiments, not shown in the attached figures, the second walls 34a, 34b have a structure similar to the one of the first walls 25a, 25b or the first walls 25a, 25b are structured as the second walls 34a, 34b, i.e. the first walls 25a, 25b are born by a first cylindrical wall that is radially spaced from the outer wall 3 of the casing 2 and is connected to said outer wall 3 of the casing 2 by first radial elements. Furthermore, for facilitating the assembly and disassembly, the first axial section 24 and the second axial section 38 with the respective first walls 25a, 25b and second walls 34a, 34b and any cylindrical walls 37 can be divided into angular sectors juxtaposed with each other (dotted lines of figure 4). Each of the angular sectors comprises furthermore for example one of the radial elements 37a.

[0170] The turbines 6 of the turbo-compressors 1 shown in figures 1 and 2 have a maximum diameter similar to the one of the impeller 8 of the respective compressor 5. However, it is possible that in other embodiments the radial dimensions of turbine 6 and compressor 5 are different from each other and the casing is shaped accordingly.

[0171] The variant of figure 6 shows a double turbine 6 keyed on the rotating shaft 7, i.e. a turbine 6 comprising two bodies 15 between them identical and arranged symmetrically with respect to a plane orthogonal to the main axis X-X. The positioning of the two bodies 15 identical to each other and arranged symmetrically with respect to a plane orthogonal to the main axis X-X allows advantageously to balance the axial thrust.

[0172] In another variant, not shown, the two bodies 15 identical to each other are arranged in series one after another on the rotating shaft 7 with its own first axial ends facing the same part. Furthermore, for example, between the two bodies 15 is keyed the impeller of the compressor 5.

[0173] The variant of figure 7 shows a multistage turbine 6 that has two series of turbine inlets 19’, 19” formed on respective cylindrical surface portions 17’, 17” of the body 15. Each series of inlets 19’, 19” is part of a respective helical duct and is connected to a respective turbine outlet 20’, 20”. Each series of inlets 19’, 19” is coupled to a respective first annular chamber 28’, 28”. Advantageously, the variant of figure 7 allows to optimize the operation of the turbine in case of variable loads.

[0174] The variant of figure 8 shows a body 15 of the turbine 6 that bears or integrates the balancing mass 13 above mentioned.

[0175] In the variant of figure 9, the first wall 25a closest to the second axial end of the body 15 is arranged about the substantially conical part 18 of the body 15 and the respective sealing element 27 is radially interposed between the radially inner peripheral edge 26 and said substantially conical part 18. The first wall 25b positioned at the first axial end of the body 15 is side by side with a face of the body 15 orthogonal to the main axis X-X and the respective sealing element 27 is axially arranged between the respective radially inner peripheral edge 26 and said face. With this arrangement, the fluid pressure in the first annular chamber 28 acts on a portion of the substantially conical part and axially balances, at least in part, an opposed axial thrust generated by the fluid inside the helical duct 16.

[0176] Figure 10 shows a variant in which the body 15 of the turbine 6 is still coaxial to the rotating shaft 7 but is not integral to said rotating shaft 7. The body 15 is supported on the rotating shaft 7 via an axial bearing 40 and a radial bearing 41 so as to be able to rotate with respect to the rotating shaft 7 about the main axis X-X. The impeller of the compressor s, not visible in figure 10, is instead integral to the rotating shaft 7. The body 15 of the turbine 6 and the rotating shaft 7 are mechanically connected to each other via a speed reducer / multiplier 42 of epicycloidal or planetary type.

[0177] The speed reducer / multiplier 42, per se known, comprises a shell or crown provided with a radially internal toothing and fixed in the casing 3, a pinion 44 keyed on the and integral to the rotating shaft 7 and three planetary gears 45 (only two of which shown in figure 10) arranged about the pinion 44 and geared each one with said pinion 44 and with the crown toothing 43. Furthermore, planetary gear shafts 45 are integrally connected to the body 15 of the turbine 6. For example, if the compressor 5 is centrifugal, the speed reducer / multiplier 42 is configured so that the turbine 6 revolutions at a lower number of revolutions per minute than the number of revolutions per minute at which the compressor 5 rotates. It is not excluded however that the speed reducer / multiplier 42 can be configured so that the turbine 6 rotates at a higher or greater number of revolutions per minute than the number of revolutions per minute at which the compressor 5 rotates.

[0178] The speed reducer / multiplier 42 is also schematically shown in figure 2.

[0179] In the embodiment of figure 11 , the compressor 5 is of the piston type and comprises a cylinder 46 integral to the casing 2 in which is housed a piston 47 that can slide in the cylinder 46. The piston 47 is connected via a connecting rod 48 to a crank portion 49 of the rotating shaft 7 eccentric with respect to the main axis X-X. The compressor 5 of the piston type is axially placed between the turbine 6 and the electric motor 4 and the rotating shaft 7 is supported by bearings 50 placed between the electric motor 4 and the crank portion 49 and at a terminal end of the rotating shaft 7 opposite with respect to the electric motor 4. The compressor 5 is therefore placed among the bearings 50. In other embodiment variants, the turbine 6 is located cantilevered with respect to the two bearings 50 or the compressor 5 is located cantilevered with respect to the two bearings 50.

[0180] In the embodiment of figure 12, the rotating shaft 7 of the electric motor 4, or shaft turbine, bears the body 15 of the turbine 6 which rotates integral with it. The compressor 5 of scroll type is mounted at an end of a compressor shaft 51. The rotating shaft 7 and the compressor shaft 51 are coaxial and are connected to each other by a speed reducer / multiplier 42 axially interposed between an end of the rotating shaft 7 and an end of the compressor shaft 51. The speed reducer / multiplier 42 can be per se known and is therefore been schematically represented. In detail, the body 15 of the turbine 6 can be connected to the compressor shaft 51 by interference, screwing or by means of a crown with teething 43.

[0181] In a further embodiment, the speed reducer / multiplier 42 is interposed between the electric motor 4 and the turbine 6, preferably between the compressor 5 and the turbine 6. In particular, in this embodiment, the components are arranged along the main axis X-X in the following order: electric motor 4, compressor 5, speed reducer / multiplier 42 and turbine 6.

[0182] The embodiment of figure 13 differs from the one of figure 12 since the rotating shaft 7 and the compressor shaft 51 are not coaxial but partially side-by-side. The compressor 5 is of the centrifugal type and comprises two propellers 8. The speed reducer / multiplier 42 comprises a first gear 52 keyed on the turbine shaft and a second gear 53 keyed on the compressor shaft 51 .

[0183] In a further embodiment, the turbine 6 is arranged on the compressor shaft 51 . The body 15 of the turbine 6 can be keyed on the compressor shaft 51. The speed reducer / multiplier 42 is interposed between the motor and the rotors and allows to separate from each other the rotation of the rotating shaft 7 and the rotation of the rotors.

[0184] In further embodiments, the compressor 5 can also be of different types, for example screw or rotary type.

[0185] In case of a screw compressor with a shaft for each screw, the turbo-compressor 1 can comprise two turbines, each arranged on the shaft of a respective screw of the compressor, or a single turbine constrained to the shaft of a screw and operatively connected to the shaft of the other screw by means of the speed reducer / multiplier 42. Figure 16 shows a portion of the turbo-compressor 1 according to a further variant in which the centrifugal bladed compressor 5 is keyed on the rotating shaft 7 while the turbine 6 is mounted on the rotating shaft 7 via bearings and rotates with respect to said rotating shaft 7. Part of the turbine 6 is positioned in position radially inner to the compressor 5 and is coaxial to the compressor 5. The turbine 5 is connected to the speed reducer / multiplier 42, not visible.

[0186] In a further embodiment shown for example in figure 17, the turbo-compressor 1 comprises two turbines 6 arranged in series to each other or a double turbine 6, i.e. with due bodies 15. The turbine outlet 20 of one of the two turbines 6 is oriented axially and the turbine outlet 20 of the other turbine 6 is connected to the inner channel 21 of the rotating shaft 7. The turbo-compressor 1 has two inlets 23 formed through the base body 63 of the casing 2. Each inlet 23 is in fluid communication with the turbine inlets 19 of a respective of the two turbines 6.

[0187] It is not excluded, however, that the turbo-compressor 1 can comprise only one of the turbines 6 or that both the turbines 6 can have outlets 20 axially arranged or connected to the inner channel 21 of the rotating shaft 7.

[0188] The casing 2 comprises at least one removable portion 64 and a base body 65 removably connected to the removable portion 64. The removable portion 64 is constrained by means of screws or equivalent fastening means of known type. The removable portion 64 is configured to allow the access to the inner volume of the casing 2 when released from the base body 65 and close the access to the volume of the casing 2 when constrained to the base body 65. The connection between the removable portion 64 and the base body 65 can hermetically insulate the interior of the casing from the outer environment, for example by means of appropriate gaskets.

[0189] In case the removable portion 64 defines a lateral portion of the casing, the turbine can be removed from the casing by moving it along the main axis X-X. With reference to figure 17, the turbines 6 are removable from the casing by disconnecting the removable portion 64 from the base body 65 and moving the turbines 6 towards left along the main axis X-X.

[0190] In detail, the removable portion and the base body can be respectively defined by an upper portion and a lower portion of the casing that extend along the main axis X-X. In other words, the casing is openable and divisible into two halves. For example, the removable portion 64 and the base body 65 can be defined by respective halves of the casing. A removable portion 64 defined by a portion or upper half of the casing allows to position the turbine in such a way that it is not cantilevered on the rotating shaft 7.

[0191] In the embodiment shown in figure 17, the removable portion 64 is defined by a lateral wall of the casing 2 transversal to the main axis X-X. The removable portion 64 has an opening for the passage of the rotating shaft 7 and / or that defines the outlet 22 of the casing 2. In case the removable portion 64 is defined by the upper portion, or upper half, of the casing 2, the turbine can be removed moving it upward, then transversely to the main axis X-X.

[0192] In detail, the turbo-compressor 1 comprises walls 25a, 25b delimiting an annular chamber 28 for each of the two turbines 6. The walls 25a, 25b are too removable from the turbo-compressor 1 , i.e. connected to the base body 65 of the casing 2 in a removable manner.

[0193] Advantageously, constraining the removable portion 64 and the various walls to the base body 65 of the casing 2 through removable screws or equivalent means allows to simplify maintenance operations on the turbo-compressor 1 and, possibly, remove and / or replace one or both the turbines in a quick and easy manner. In fact, by simply removing the screws that constrain the removable portion to the base body 65, is possible to disassemble the removable portion 64 and move the turbine 6 along the main axis X-X by removing it from the inside of the casing 2. The removal of the turbine 6 results quick and does not require to act on the other components of the turbo-compressor as electric motor 4 and compressor 5. In in case of malfunctioning, it is possible to remove the turbine 6 and close the casing again allowing the operation of the turbo-compressor 1 in the absence of the turbine 6.

[0194] According to an aspect, the turbo-compressor 1 comprises a diffuser element 66 connected to the casing 2 and associated to the turbine outlet 20 and to the outlet 22 of the inner channel 21. The diffuser element 66 is located at the removable portion 64 of the casing 2. The diffuser element 66 is connected to the casing 2. This connection can be of the type of a removable connection. The diffuser element 66 is configured to direct the fluid in outlet from the inner channel 21 and from the turbine 6. According to an aspect, the turbo-compressor 1 according to the invention has a high versatility of use as it is employable for different applications and uses. In fact, it is possible to modify the turbo-compressor 1 for a specific use by varying one or more of the operating parameters such as: fluid used, turbine typology, blade orientation (IGV), temperature and operating pressure. For example, the fluid can be propane to use the turbo-compressor in a refrigeration machine or butane to use the turbo-compressor in a heat pump.

[0195] Figure 14 shows a refrigerating apparatus 54 comprising a turbo-compressor 1 of the above-described type.

[0196] The refrigerating apparatus 54 comprises said turbo-compressor 1 , an evaporator 55, a condenser 56. Ducts connect among them the turbo-compressor 1 , the evaporator 55 and the condenser 56 contain a working fluid, a cooling fluid, in such a way as to form a refrigerating circuit and to define the refrigerating apparatus 54 configured to actuate a refrigerating cycle.

[0197] In figure 14 the evaporator 55 has an inlet 57 and an outlet 58, the condenser 56 has an inlet 59 and an outlet 60. The outlet 60 of the condenser 56 is connected to the inlet 23 in the casing 2 and then to the turbine inlets 19 and the inlet 59 of the condenser 56 is connected to an outlet 61 from the compressor 5. The outlet 58 of the evaporator 55 is connected to an inlet 62 in the compressor 5 and the inlet 57 of the evaporator 55 is connected to the outlet 33 from the casing 2 and then to the outlet 20 of the helical duct 16.

[0198] The working fluid circulating in the refrigerating circuit is compressed in the compressor 5 operated by the electric motor 4 before entering the condenser 56 and made to expand into the “bladeless” expander / turbine 6 before it enters the evaporator 55.

[0199] The attached figure 15 shows the refrigerating cycle (T-S) actuated by the apparatus 54 according to the invention described here (continuous line) and a refrigerating cycle actuated by a traditional apparatus (dotted line), wherein instead of the turbocompressor 1 of the present invention is present a compressor and a lamination / expansion valve, i.e. instead of in the turbine according to the invention, the working fluid is made to expand via the lamination / expansion valve. According to the traditional cycle, the working fluid is compressed in the compressor from A to B, then cools and condenses in the condenser from B to C, then expands in the lamination valve from C to D and evaporates in the evaporator from D to A. According to the cycle operated by the apparatus 54 of the invention, the working fluid is compressed in the compressor from A to B, then cools and condenses in the condenser 56 from B to C, then expands in the “bladeless” turbine 6 from C to D’ and evaporates in the evaporator 55 from D’ to A.

[0200] As it can be noted, the two cycles are substantially overlapping except in the expansion zone / phase C-D, C-D’ so the area enclosed by the refrigerating cycle operated by the apparatus 54 according to the invention is greater than the area enclosed by the traditional cycle, so it involves a specific work greater in absolute value. Furthermore, it is closer to an ideal cycle.

[0201] According to an aspect, the turbo-compressor 1 can be or be part of a propulsion device for space use and / or of a cryogenic turbopump.

[0202] List of elements turbo-compressor 1 casing 2 outer wall 3 electric motor 4 compressor 5 turbine 6 rotating shaft 7 impeller 8 cochlea spiral 9 statoric part 10 fixed cochlea spiral 11 balancing disc 12 balancing mass 13 body 15 helical ducts 16 cylindrical surface 17 substantially conical part 18 turbine inlets 19 turbine outlet 20 inner channel 21 outlet 22 from the casing inlet 23 first axial section 24 first walls 25a, 25b radially inner circular peripheral edge 26 sealing elements 27 first annular chamber 28 inlet vanes 29 ducts 30 volume 31 second annular chamber 32 outlet 33 from the casing second walls 34a, 34b sealing element 35 radially inner circular peripheral edge 36 second cylindrical wall 37 radial elements 37a second axial section 38 openings 39 axial bearing 40 radial bearing 41 speed reducer / multiplier 42 shell or crown 43 pinion 44 planetary gear 45 cylinder 46 piston 47 connecting rod 48 eccentric portion (crank) 49 bearings 50 com pressor shaft 51 first gear 52 second gear 53 refrigerating apparatus 54 evaporator 55 condenser 56 inlet 57 evaporator outlet 58 evaporator inlet 59 condenser outlet 60 condenser outlet 61 compressor inlet 62 compressor septum 100 housing 110 axis Y-Y main axis X-X removable portion 64 base body 65 diffuser element 66

Claims

CLAIMS1. Turbo-compressor, comprising:- a casing (2);- a turbine (6) mounted in the casing (2) so as to be able to rotate with respect to the casing (2) about an axis of rotation; wherein the turbine (6) is bladeless and comprises at least one body (15) and at least one helical duct (16) obtained inside the body (15) and developing in loops from at least one turbine inlet (19) to at least one turbine outlet (20); wherein a distance of the helical duct (16) from the axis of rotation decreases from said at least one turbine inlet (19) to said at least one turbine outlet (20);- an electric motor (4) provided with a rotating shaft (7) so as to be able to rotate with respect to the casing (2) about an its own main axis (X-X), the electric motor (4) being optionally mounted in the casing (2);- a compressor (5) mounted in the casing (2) and connected to said rotating shaft (7); wherein the turbine (6) is mounted integral with the rotating shaft (7) or wherein the turbine (6) and the rotating shaft (7) are mechanically connected to each other via a speed reducer / multiplier (42) or wherein the compressor (5) is mounted integral with the rotating shaft (7) or wherein the compressor (5) and the rotating shaft (7) are mechanically connected to each other via the speed reducer / multiplier (42); wherein the turbine (6), the compressor (5), possibly the electric motor (4) and the rotating shaft (7) are all enclosed in the casing (2) and the turbine (6) and the compressor (5) are separate elements.

2. Turbo-compressor according to claim 1 , wherein the main axis (X-X) of the rotating shaft (7) and the axis of rotation coincide and the turbine (6) is coaxial to the rotating shaft (7).

3. Turbo-compressor according to claim 1 or 2, wherein the casing (2) delimits internally a volume (31 ) for housing the turbine (6), the electric motor (4) and the rotating shaft (7).

4. Turbo-compressor according to claim 3, wherein a septum (100) divides said volume (31 ) from a housing (110) of the compressor (5), wherein the housing (110) is inside the casing (2).

5. Turbo-compressor according to any one of claims 1 to 4, wherein the compressor (5) comprises a piston (47) and a connecting rod (48) and the rotating shaft (7) defines a crank (49) or wherein the compressor (5) is of the scroll type and is mounted at a terminal end of the rotating shaft (7) or wherein the compressor (5) is centrifugal or twin rotary or screw or rotary.

6. Turbo-compressor according to any one of claims 1 to 5, wherein the body (15) of the turbine (6) has tapered outline from a first axial end toward a second axial end; wherein said at least one turbine inlet (19) comprises a plurality of turbine inlets (19) formed on a radially peripheral portion of the body (15) and said at least one turbine outlet (20) is located on the second axial end of the body (15); wherein the casing (2) delimits a first annular chamber (28) arranged around the radially peripheral portion of the body (15), the first annular chamber (28) being connected to an inlet (23) in the casing (2).

7. Turbo-compressor according to claim 6, wherein the casing (2) contains a second annular chamber (32) arranged around the second axial end of the body (15), the second annular chamber (32) being in fluid communication with said at least one turbine outlet (20) and being connected to an outlet (33) from the casing (2); or wherein the rotating shaft (7) delimits an inner channel (21 ) having at least one end in fluid communication with said at least one turbine outlet (20) and an opposite end connected to an outlet (22) from the casing (2); optionally, inlet vanes (29) being arranged in the first annular chamber (28); said inlet vanes (29) being movable and adjustable to regulate a flow to the turbine inlets (19).

8. Turbo-compressor according to any one of claims 6 or 7, comprising a pair of first walls (25a, 25b) supported in the casing (2) and arranged about the radially peripheral portion of the body (15); wherein the first walls (25a, 25b) face each otherand delimit the first annular chamber (28) between them; wherein each of the first walls (25a, 25b) comprises a sealing element (27) located at its own radially inner circular peripheral edge (26) and placed at the radially peripheral portion of the body (15).

9. Turbo-compressor according to claim 8 when claim 6 depends on 3 or 4, wherein channels or openings (30; 39) connect among them areas of said volume (31 ) separated by the pair of first walls (25a, 25b).

10. T urbo-compressor according to any one of claims 1 to 9, comprising at least one balancing mass (13) integral to the body (15) of the turbine (6) and eccentric to the axis of rotation (X-X); or wherein the balancing mass is the turbine (6) itself; wherein the balancing mass (13) is configured to balance imbalances due to the compressor (5).

11. Turbo-compressor according to any one of the preceding claims, wherein said turbine inlet (19) comprises various series of turbine inlets (19’, 19”) formed on radially peripheral portions of the body (15); each series comprising a plurality of inlets (19’, 19”) arranged on a respective radially peripheral portion of the body (15) and along a respective circular path; the series being axially offset to each other.

12. Turbo-compressor according to claim 3 or any one of the preceding claims 3 to11 when combined with claim 3, wherein said volume (31 ) of the casing (2) is void or in connection with: a cooling circuit that determines the circulation of a cooling oil or gas in the volume (31 ), or a cooling liquid recovery circuit.

13. T urbo-compressor according to claim 3 or any one of the preceding claims 3 to12 when combined with claim 3, wherein the casing (2) comprises a base body (65) and at least one removable portion (64), the removable portion (64) being removably connected to the base body (65) and suitable for allowing the access to the volumeto said volume (31 ) of the casing (2) when constrained to the base body (65).

14. Turbo-compressor according to any one of the preceding claims, comprising a diffuser element (66) connected to the casing (2) and associated to the turbine outlet(20) or to the outlet (22) of the inner channel (21 ), said diffuser element (66) being configured to direct the fluid in outlet from said turbine (6), preferably from said inner channel (21 ).

15. Refrigerating apparatus (54) for actuating a refrigerating cycle, said refrigerating apparatus (54) comprising: at least one turbo-compressor (1 ) according to any one of the preceding claims; at least one condenser (56); at least one evaporator (55); ducts connecting said at least one condenser, said at least one evaporator and said at least one turbo-compressor for forming a refrigerating circuit.

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