INTEGRATED MOTOR-COMPRESSOR ASSEMBLY

Abstract

This integrated motor-compressor assembly (1) comprises: a drive shaft (3), magnetic bearings (9, 10) supporting the drive shaft (3), a gas inlet (7), a first compression section (4) cantilevered at a first end of the drive shaft (3) and comprising a housing (4e) having a compression wheel (4c) and configured to compress a gas flowing from the gas inlet (7), and a second compression section (5) at a second end of the drive shaft, the first compression section comprising a cantilevered cooling fan (12) configured to supply a portion of the gas taken from the gas inlet (7) to a cooling loop (11) of the integrated motor-compressor assembly (1), said portion of the taken gas being a cooling gas, the cooling fan (12) being placed between the first compression section (4) and the second compression section (5),the integrated motor-compressor assembly (1) further comprising a suction line (15) configured to supply gas from the gas inlet (7) to the cooling fan (12). Figure for abstract: [Fig 1],

Description

Title of the invention: INTEGRATED MOTOR-COMPRESSOR ASSEMBLY FIELD OF THE INVENTION

[0001] The present invention relates to an integrated motor-compressor assembly and in particular relates to a specific arrangement of a cooling fan. DESCRIPTION OF THE ASSOCIATED TECHNIQUE

[0002] An integrated motor-compressor assembly may include an electric motor mounted on a drive shaft to drive said shaft. The drive shaft is generally rotatably supported by two magnetic bearings arranged on either side of the electric motor.

[0003] A compression section may be arranged at each end of the drive shaft.

[0004] The electric motor and the magnetic bearings are subject to losses generated, for example, by eddy currents.

[0005] In order to cool the electric motor and the magnetic bearings, the integrated motor-compressor assembly comprises a cooling loop comprising a filtration device filtering a portion of a compressed gas by means of a first compression section, the portion of compressed gas being the cooling gas flowing into the electric motor and the bearings.

[0006] When the pressure of the compressed gas is too high to supply the cooling loop, a control valve expands the compressed gas filtered by the filtration device to decrease the pressure of the compressed gas to a predetermined pressure.

[0007] However, in order to decrease the pressure of the cooling gas, the control valve dissipates part of the energy used to drive the first compression section to compress the gas such that the efficiency of the integrated motor-compressor assembly deteriorates.

[0008] Furthermore, the control valve is a pressure regulating component that may be defective, decreasing the reliability of the integrated motor-compressor assembly.

[0009] The current solution with two cantilevered wheels arranged symmetrically to avoid competition (one on each side of the rotor) uses a control valve for engine cooling with associated excessive compression work to circulate a flow.

[0010] No known concept describes a workable solution using a fan with an attachment on the other side of the rotor.

[0011] It is necessary to avoid at least some of the previously mentioned disadvantages. SUMMARY

[0012] According to one aspect, an integrated motor-compressor assembly is provided.

[0013] The integrated motor-compressor assembly comprises a drive shaft, magnetic bearings supporting the drive shaft, a gas inlet, a first compression section cantilevered at a first end of the drive shaft and comprising a housing having a compression wheel and configured to compress a gas flowing from the gas inlet, and a second compression section at a second end of the drive shaft, the first compression section comprising a cooling fan cantilevered and having a fan compression wheel, the cooling fan being configured to be driven by the drive shaft to supply a portion of the gas taken from the gas inlet to a cooling loop of the integrated motor-compressor assembly, said portion of the taken gas being a cooling gas,the cooling fan being positioned between the first compression section and the second compression section and such that a high pressure portion of the compression wheel faces a low pressure portion of the fan compression wheel.

[0014] The integrated motor-compressor assembly further comprises a suction line for supplying gas from the gas inlet to the cooling fan.

[0015] Advantageously, the integrated motor-compressor assembly further comprises an electric motor mounted on the drive shaft, the cooling loop being configured to cool said electric motor by means of a flow of the cooling gas.

[0016] Preferably, the cooling loop comprises a filtration device connected to the electric motor so that a first portion of the cooling gas, filtered by said filtration device, flows through the electric motor to cool said electric motor.

[0017] Advantageously, the filtration device is further connected to each bearing so that a second portion of the filtered cooling gas flows through the bearings to cool them.

[0018] Advantageously, the cooling fan is configured to compress the cooling gas to supply the compressed cooling gas to the cooling loop of the integrated motor-compressor assembly and the suction line comprises a direct channel between the gas inlet and the low pressure portion of the fan compression wheel of the cooling fan. cooling, the filtration device comprising an inlet connected to a fan gas outlet of the cooling fan.

[0019] Preferably, the cooling fan is configured to draw in the cooling gas and the suction line comprises a direct channel between the gas inlet and an inlet of the filtration device such that the cooling fan draws in the filtered cooling gas heated by the electric motor.

[0020] Advantageously, the integrated motor-compressor comprises a return line and the cooling fan comprises a fan gas outlet, the return line connecting the fan gas outlet of the cooling fan and the axial gas inlet of the compression wheel of the first compression section.

[0021] Preferably, the return line directly connects the fan gas outlet of the cooling fan and the axial gas inlet of the compression wheel of the first compression section.

[0022] Preferably, the fan compression wheel is arranged in the housing of the first compression section and is configured to be driven by the drive shaft.

[0023] Preferably, the fan compression wheel is arranged in a cantilevered configuration.

[0024] Preferably, in a more particular embodiment, the second compression section is cantilevered at the second end of the drive shaft.

[0025] The integrated motor-compressor assembly may further comprise decompression labyrinths with integrated sealing means coupled to at least one of the compression sections and configured to prevent gas from escaping to the electric motor from said compression section. Brief description of the drawings

[0026] Other advantages and characteristics of the invention will appear on examining the detailed description of the embodiments, this being in no way restrictive, and the appended drawings in which:

[0027] [Fig.l] schematically illustrates an embodiment of an integrated motor-compressor assembly according to the invention; and

[0028] [Fig.2] schematically illustrates a second embodiment of the integrated motor-compressor assembly according to the invention. DETAILED DESCRIPTION

[0029] Reference is made to [Fig.l] which schematically represents a first embodiment of an integrated motor-compressor assembly 1, comprising: a drive shaft 3, - a gas inlet 7, - magnetic bearings 9, 10 supporting the drive shaft 3, - a first compression section 4 cantilevered at a first end of the drive shaft 3 comprising a housing 4e having a compression wheel 4c and configured to compress a gas flowing from the gas inlet 7, and - a second compression section 5 at a second end of the drive shaft.

[0030] The first compression section comprises a cantilevered cooling fan 12 having a fan compression wheel 12a and being configured to be driven by the drive shaft 3 to supply a portion of the gas taken from the gas inlet 7 to a cooling loop 11 of the integrated motor-compressor assembly 1, said portion of the taken gas being a cooling gas.

[0031] The cooling fan 12 is placed between the first compression section 4 and the second compression section 5 and such that a high pressure portion of the compression wheel 4c faces a low pressure portion of the fan compression wheel 12a.

[0032] A gas to be compressed by a compression wheel enters through the low pressure portion of the compression wheel and exits through the high pressure portion of the compression wheel. The pressure of the gas in the high pressure portion of the compression wheel is greater than the pressure of said gas in the low pressure portion of the compression wheel.

[0033] The cooling fan 12 is mounted on the drive shaft to supply a portion of the gas taken from the gas inlet 7 of the integrated motor-compressor assembly 1 to the cooling loop 11, said portion of the gas taken from the gas inlet 7 of the integrated motor-compressor assembly 1 being called cooling gas.

[0034] The integrated motor-compressor assembly 1 further comprises a suction line 15 for supplying gas from the gas inlet 7 to the cooling fan 12. Preferably, the gas can be supplied when the cooling fan 12 is activated.

[0035] This integrated motor-compressor assembly 1 makes it possible to produce an integrated double-overhang motor-compressor assembly combined with a fan 12 rather than with a control valve known in the prior art which generates a significant pressure drop and flow rate drop in the assembly.

[0036] Indeed, the known use of a control valve arranged after a gas filter penalizes the flow pressure and the efficiency, and is not known with a symmetrical double-overhang configuration, but only for integrated motor-compressor assemblies with free shaft ends.

[0037] Advantageously, the integrated motor-compressor assembly 1 comprises an electric motor 2 mounted on the drive shaft 3, the cooling loop 11 being configured to cool said electric motor 2 by means of a flow of the cooling gas.

[0038] This solution allows for an axial gas inlet 7, which is the most compact solution, and allows the flow to circulate from the gas inlet 7 and axially through the first compression section 4 and through the cooling fan 12, thereby minimizing the gas intake and the effect on the flow pressure for the cooling function of the elements of the integrated motor-compressor assembly 1.

[0039] The integrated motor-compressor assembly 1 comprises a sealed casing 6 in which the electric motor 2, the drive shaft 3 and the two compression sections 4, 5 are placed.

[0040] The first compression section 4 is cantilevered at a first end of the drive shaft 3 and the second compression section 5 is cantilevered at the second end of the drive shaft 3.

[0041] Each compression section 4, 5 comprises a gas inlet 4a, 5a and a gas outlet 4b, 5b.

[0042] The gas inlet 4a is an axial gas inlet, and the gas inlet 5a of the second compression section 5 is an axial gas inlet.

[0043] The axial gas inlet 4a of the first compression section 4 is connected to a gas inlet 7 of the integrated motor-compressor assembly 1, the axial gas inlet 5a of the second compression section 5 is connected to the gas outlet 4b of the first compression section 4 and the gas outlet 5b of the second compression section 5 is connected to a gas outlet 8 of the integrated motor-compressor assembly 1.

[0044] Each compression section 4, 5 may comprise a compression wheel 4c, 5c.

[0045] Each compression section 4, 5 comprises sealing devices 4d, 5d to prevent gas from escaping into the sealed casing 6 from said compression section 4, 5.

[0046] The sealing devices 4d, 5d may comprise decompression means, such as labyrinths, to prevent unforeseen leaks of gas flow, in particular of polluted gas flow towards the electric motor 2 and / or the bearings 9, 10.

[0047] Each bearing 9, 10 comprises a radial bearing and / or an axial bearing.

[0048] Preferably, in a more particular embodiment, the second compression section 5 is cantilevered at the second end of the drive shaft 3.

[0049] The integrated motor-compressor assembly 1 may, for example, further comprise decompression labyrinths with integrated sealing means 4d, 5d coupled to at least one of the compression sections 4, 5 and configured to prevent gas from escaping to the electric motor 2 from said compression sections 4, 5.

[0050] The electric motor 2 is intended to drive the compression sections 4, 5 so that the first compression section 4 compresses a gas flowing into the gas inlet 7 of the integrated motor-compressor assembly 1 and distributes the compressed gas to the gas inlet 5a of the second compression section 5.

[0051] The electric motor 2 is further intended to drive the second compression section 5 to further compress the compressed gas distributed by the first compression section 4, the second compression section distributing the compressed gas to the gas outlet 8 of the integrated motor-compressor assembly 1.

[0052] The first compression section 4 may also comprise an axial gas bearing (not shown) configured to be held axially by means of a jacket, and this axial bearing could also be cooled by the cooling loop IL

[0053] The drive shaft 3 is supported by the bearings 9, 10 in the sealed casing 6.

[0054] The bearings 9, 10 may comprise gas bearings or, preferably, bearings magnetic.

[0055] It is assumed hereinafter that the bearings 9, 10 are magnetic bearings. Each magnetic bearing 9, 10 comprises a radial magnetic bearing and / or an axial magnetic bearing.

[0056] A first bearing 9 is arranged between the first compression section 4 and the electric motor 2, and a second bearing 10 is arranged between the second compression section 5 and the electric motor 2.

[0057] The term "cantilevered" means that a component of the integrated motor-compressor assembly such as the cooling fan 12, the first compression section 4 or the second compression section 5 is not located between the first and second bearings 9, 10.

[0058] Said component is positioned cantilevered relative to the first and second bearings 9, 10.

[0059] For example, the cooling loop 11 comprises a filtration device 13 connected to the cooling fan 12 and to the electric motor 2 so that a first portion of a compressed cooling gas, filtered by said filtration device 13, flows through said electric motor 2. In a particular embodiment, the gas may be supplied to cool said electric motor 2.

[0060] This configuration allows for optimal overall efficiency of the cooling fan 12 combined with the double cantilever solution to achieve simple and efficient rotor dynamics.

[0061] In both embodiments, as shown, the filtration device 13 can be arranged outside the sealed casing 6.

[0062] Alternatively, the filtration device 13 can be arranged inside the sealed casing 6.

[0063] Unfiltered gas may contain particles that may damage components inside the sealed casing 6, for example, that may damage the magnetic bearings 9, 10, the electric motor 2.

[0064] The filtration device 13 is designed to remove these particles from the gas flowing into the gas inlet 7 of the integrated motor-compressor assembly 1.

[0065] The filtration device 13 may further be connected to each bearing 9, 10 so that a second portion of the filtered cooling gas flows through the bearings 9, 10 to cool them.

[0066] The first compression section 4 may comprise a casing 4e comprising the compression wheel 4c, the axial gas inlet 4a of the first compression section 4, the gas outlet 4b of the first compression section 4.

[0067] The cooling fan 12 may be arranged cantilevered in the casing 4e of the first compression section 4.

[0068] The gas inlet 7 of the first compression section 4 opens onto a low pressure part of the compression wheel 4c of the first compression section 4.

[0069] The casing 4e of the first compression section 4 further comprises a fan gas outlet 12b discharging the cooling gas compressed by the fan compression wheel 12a and a fan gas inlet 12c connected to the gas inlet 7 for supplying gas to the low pressure part of the cooling fan 12.

[0070] In the first embodiment described in [Fig.l], the suction line comprises a direct channel 15 between the gas inlet 7 and the low pressure part of the fan compression wheel 12a of the cooling fan 12, the filtration device 13 comprising an inlet 13a connected to the fan gas outlet 12b of the cooling fan 12.

[0071] The direct channel 15 may comprise a pipe.

[0072] In this first embodiment, when the electric motor 2 drives the drive shaft 3, the cooling fan 12 compresses the cooling gas to provide the cooling loop 11 with compressed cooling gas which enters the filtration device 13 by passing through its inlet 13a, and said filtration device 13 filters the compressed cooling gas.

[0073] An output 13b of the filtration device 13 is connected to the electric motor 2 and to the bearings 9, 10.

[0074] Furthermore, in this simplest embodiment, the cooling fan 12 is installed cantilevered on the compression wheel 4c of the first compression section 4, sucks in the polluted air from the gas inlet 7 and pushes this gas into the inlet 13a of the filtration device 13, which maximizes the airflow efficiency and allows a fan to be incorporated on the first wheel included in the first compression section 4.

[0075] The filtered and compressed cooling gas then flows into the electric motor 2 and the magnetic bearings 9, 10.

[0076] A first portion of the compressed cooling gas filtered by the filtration device 13 can flow through the electric motor 2 to cool the electric motor 2 and a second portion of the compressed cooling gas filtered by the filtration device 13 can flow through the magnetic bearings 9, 10 to cool the magnetic bearings 9, 10.

[0077] The first part of the compressed cooling gas heated by the electric motor 2 and the second part of the compressed cooling gas heated by the magnetic bearings 9, 10 flow to the gas inlet 7 of the integrated motor-compressor assembly 1 through an exhaust duct 14 connecting the gas inlet 7 of the electric motor 2 and the bearings 9, 10.

[0078] The cooling fan 12 may be designed so that the pressure at the fan gas outlet 12b is equal to a predetermined pressure determined according to the flow of cooling gas circulating in the electric motor 2 and in the magnetic bearings 9, 10, and according to the pressure drop in the cooling loop 11.

[0079] [Fig.2] schematically represents a second embodiment of the integrated motor-compressor assembly 1.

[0080] The same references designate the same elements as those previously referenced in the first embodiment of the integrated motor-compressor assembly 1 shown in [Fig.l].

[0081] The integrated motor-compressor assembly 1 comprises the electric motor 2, the drive shaft 3, the first and second compression sections 4, 5, the sealed casing 6, the gas inlet 7, the gas outlet 8 and the bearings 9, 10 arranged as described above in the first embodiment of the integrated motor-compressor assembly 1.

[0082] The integrated motor-compressor assembly 1 further comprises the cantilevered cooling fan 12 and the filtration device 13 arranged in the integrated motor-compressor assembly 1 as described above.

[0083] As explained below, in the second embodiment, the cooling fan 12 is intended to suck in cooling gas.

[0084] The fan gas inlet 12c of the cooling fan 12 is arranged in the sealed housing 6 to suck gas into the sealed housing 6.

[0085] The integrated motor-compressor assembly 1 further comprises the suction line, comprising a direct channel 16 between the gas inlet 7 and an inlet 13a of the filtration device 13 so that the cooling fan 12 sucks in the filtered cooling gas heated by the electric motor 2.

[0086] The direct channel 16 may comprise a pipe.

[0087] The integrated motor-compressor assembly 1 further comprises a return line 17 connecting the fan gas outlet 12b of the cooling fan 12 and the axial gas inlet 4a of the compression wheel 4c of the first compression section 4.

[0088] The return line 17 can directly connect the fan gas outlet 12b of the cooling fan 12 and the axial gas inlet 4a of the compression wheel of the first compression section 4 so that no other element is arranged on the return line 17. Preferably, the return line directly connects the fan gas outlet 12b of the cooling fan 12 and the axial gas inlet 4a of the compression wheel of the first compression section 4.

[0089] In this second embodiment, when the electric motor 2 drives the drive shaft 3, the cooling fan 12 draws the cooling gas from the inlet 7 through the electric motor 2, the bearings 9, 10 and the filtration device 13, to supply the cooling loop 11 with compressed cooling gas which first enters the filtration device 13 via its inlet 13a, which filters the compressed cooling gas directly before it comes into contact with the fan 12, unlike in the first embodiment.

[0090] In this second embodiment, the cooling fan 12 draws filtered gas from the outlet 13b of the filtration device 13 through the electric motor 2 instead of pushing it as in the first embodiment, and then pushes it back towards the axial gas inlet 4a of the first compression section 4.

[0091] The filtered air (cooling gas) distributed flowing from the outlet 13b of the filtration device 13 flows through the electric motor 2 and the magnetic bearings 9, 10, as a result of the depression created by the fan of cooling 12, and is heated by the electric motor 2 and the magnetic bearings 9, 10.

[0092] The heated cooling gas is sucked in through the fan gas inlet 12c of the cooling fan 12 and transported by the cooling fan 12 into the return line 17 connecting the fan gas outlet 12b of the cooling fan 12 to the axial gas inlet 4a of the first compression section 4.

[0093] This embodiment allows the fan function to be integrated into the first compression section 4 or to be installed as a separate component between the first compression section 4 and the electric motor 2, and to operate by suction rather than compression, thus allowing the cooling gas flow to be filtered directly at the start of the cooling loop 11, which prevents premature deterioration of components.

[0094] The two proposed architectures described above allow a cooling fan to be arranged in a double-overhanging integrated motor-compressor assembly between the two compression sections of the integrated motor-compressor assembly.

Claims

Claims

1. An integrated motor-compressor assembly (1) comprising: - a drive shaft (3), - magnetic bearings (9, 10) supporting the drive shaft (3), - a gas inlet (7), - a first compression section (4) cantilevered at a first end of the drive shaft (3) and comprising a housing (4e) having a compression wheel (4c) and configured to compress a gas flowing from the gas inlet (7), and - a second compression section (5) at a second end of the drive shaft, the first compression section comprising a cooling fan (12) cantilevered and having a fan compression wheel (12a), the cooling fan being configured to be driven by the drive shaft (3) to supply a portion of the gas taken from the gas inlet (7),to a cooling loop (11) of the integrated motor-compressor assembly (1), said portion of the gas taken being a cooling gas, the cooling fan (12) being placed between the first compression section (4) and the second compression section (5) and such that a high pressure portion of the compression wheel (4c) faces a low pressure portion of the fan compression wheel (12a), the integrated motor-compressor assembly (1) being characterized in that it further comprises a suction line (15, 16) for supplying gas from the gas inlet (7) to the cooling fan (12).,

2. An integrated motor-compressor assembly (1) according to claim 1, further comprising an electric motor (2) mounted on the drive shaft (3), the cooling loop (11) being configured to cool said electric motor (2) by means of a flow of the cooling gas.

3. An integrated motor-compressor assembly (1) according to claim 2, wherein the cooling loop (11) comprises a device filtration device (13) connected to the electric motor (2) so that a first portion of the cooling gas, filtered by said filtration device (13), flows through the electric motor (2) to cool said electric motor (2).

4. An integrated motor-compressor assembly (1) according to claim 2 or 3, wherein the filtration device (13) is further connected to each bearing (9, 10) so that a second portion of the filtered cooling gas flows through the bearings (9, 10) to cool them.

5. An integrated motor-compressor assembly (1) according to claim 3 or 4, wherein the cooling fan (12) is configured to compress the cooling gas to supply the compressed cooling gas to the cooling loop (11) of the integrated motor-compressor assembly and the suction line comprises a direct channel (15) between the gas inlet (7) and the low pressure portion of the fan compression wheel (12a) of the cooling fan (12), the filtration device (13) comprising an inlet (13a) connected to a fan gas outlet (12b) of the cooling fan (12).

6. An integrated motor-compressor assembly (1) according to claim 3 or 4, wherein the cooling fan (12) is configured to suck in the cooling gas and the suction line comprises a direct channel (16) between the gas inlet (7) and an inlet (13a) of the filtration device (13) so that the cooling fan (12) sucks in the filtered cooling gas heated by the electric motor (2).

7. An integrated motor-compressor assembly (1) according to claim 6, wherein the integrated motor-compressor assembly comprises a return line (17) and the cooling fan (12) comprises a fan gas outlet (12b), the return line (17) connecting the fan gas outlet (12b) of the cooling fan (12) and the axial gas inlet (4a) of the compression wheel of the first compression section (4).

8. An integrated motor-compressor assembly (1) according to claim 7, wherein the return line (17) directly connects the fan gas outlet (12b) of the cooling fan (12) and the axial gas inlet (4a) of the compression wheel (4c) of the first compression section (4).

9. An integrated motor-compressor assembly (1) according to any one of claims 1 to 8, wherein the fan compression wheel (12a) is arranged in the housing (4e) of the first compression section (4) and is configured to be driven by the drive shaft (3).

10. An integrated motor-compressor assembly (1) according to claim 9, wherein the fan compression wheel is arranged in a cantilevered configuration.

11. An integrated motor-compressor assembly (1) according to any one of claims 1 to 10, further comprising decompression labyrinths with integrated sealing means (4d, 5d) coupled to at least one of the compression sections (4, 5) and configured to prevent gas from escaping to the electric motor (2) from said compression sections (4, 5).

12. An integrated motor-compressor assembly according to any preceding claim, wherein the second compression section (5) is cantilevered at the second end of the drive shaft (3).

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