Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D29/00—Details, component parts, or accessories
  • F04D29/05—Shafts or bearings, or assemblies thereof, specially adapted for elastic fluid pumps
  • F04D29/056—Bearings
  • F04D29/058—Bearings magnetic; electromagnetic
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D17/00—Radial-flow pumps, e.g. centrifugal pumps; Helico-centrifugal pumps
  • F04D17/08—Centrifugal pumps
  • F04D17/10—Centrifugal pumps for compressing or evacuating
  • F04D17/12—Multi-stage pumps
  • F04D17/122—Multi-stage pumps the individual rotor discs being, one for each stage, on a common shaft and axially spaced, e.g. conventional centrifugal multi- stage compressors
  • F04D17/125—Multi-stage pumps the individual rotor discs being, one for each stage, on a common shaft and axially spaced, e.g. conventional centrifugal multi- stage compressors the casing being vertically split
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D25/00—Pumping installations or systems
  • F04D25/02—Units comprising pumps and their driving means
  • F04D25/022—Units comprising pumps and their driving means comprising a yielding coupling, e.g. hydraulic
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D25/00—Pumping installations or systems
  • F04D25/02—Units comprising pumps and their driving means
  • F04D25/06—Units comprising pumps and their driving means the pump being electrically driven
  • F04D25/0606—Units comprising pumps and their driving means the pump being electrically driven the electric motor being specially adapted for integration in the pump
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D29/00—Details, component parts, or accessories
  • F04D29/05—Shafts or bearings, or assemblies thereof, specially adapted for elastic fluid pumps
  • F04D29/053—Shafts
  • F04D29/054—Arrangements for joining or assembling shafts

Definitions

• the invention relates to a turbocharger or motor-compressor and, in particular, an integrated motor-compressor unit.
• the integrated motor-compressor groups comprise a sealed common casing 10 in which an electric motor 12 and a compressor group 14, for example with several stages, are placed, which comprises a set of impellers , such as 16, carried by a shaft 18.
• the motor 12 rotates a rotor 20, this rotor 20 being coupled to the shaft 18 of the compressor 14 by means of a rigid coupling 22.
• Bearings 24, 26 and 28 are used to support the line of shafts of the motor-compressor unit.
• the assembly is placed in a common casing 29.
• the gas to be handled is presented at the inlet E of the turbocharger then is transmitted to the successive stages of compression of the compressor unit to be delivered at the outlet S.
• An axial bearing 30 is used to prevent axial displacement of the compressor 14 during its operation.
• This type of arrangement has the advantage of considerably simplifying the line of shafts of the compressor unit insofar as the assembly constituted by the motor, its rotor and its end bearings, as well as by the rigid coupling and by the axial stop, are located inside the casing and are subjected to the pressure of the gas admitted at the inlet of the first compression stage.
• the object of the invention is therefore to overcome these drawbacks.
• the subject of the invention is therefore a centrifugal compressor group comprising a motor, at least one compressor comprising a driven shaft driven by the motor rotor and a set of at least two paddle wheels mounted on the driven shaft, the assembly consisting of the engine and the compressor being mounted in a common gas-tight casing handled by the compressor unit.
• the rotor and the driven shaft are connected by a flexible coupling arranged in the housing. It is therefore understandable that it is possible to overcome the crippling problems of alignment of the driving and driven trees.
• the rotor and the compressor shaft maintain their own vibrational behavior, insofar as these elements of the line of shafts of the compressor group remain mechanically decoupled.
• the casing comprises several casing elements secured to one another in leaktight manner, each casing element enclosing the motor or a compressor.
• the casing is provided with an orifice formed between the adjoining casing elements for access to the flexible coupling, said orifice being provided with sealing means.
• the flexible coupling includes a diaphragm or flexible blade coupling, or a twist shaft coupling.
• each end of the driven shaft and of the rotor is supported by an end bearing, which can be secured to the casing.
• the end bearings are radial magnetic bearings.
• the compressor unit includes an axial stop on which the shaft rests driven from the compressor, during operation of the turbocharger.
• This stop is for example a magnetic stop.
• FIG. 2 is a block diagram illustrating the general structure of a compressor unit according to the invention.
• FIG. 3 illustrates another embodiment of a compressor unit according to the invention
• FIG. 4 illustrates a third embodiment of a compressor unit according to the invention
• - Figure 5 illustrates a fourth embodiment of a compressor unit according to the invention
• FIG. 6 illustrates a fifth embodiment of a compressor unit according to the invention.
• a motor compressor essentially comprises an electric motor 34 at high speed of rotation (6,000 to 16,000 rpm) powered by a frequency converter and comprising a stator 36 and a rotor 38 supported by two end bearings 40 and 42, and a compressor unit 44 comprising a set of impellers 46, 48, 50 and 52, mounted on a driven shaft
• the assembly is mounted on a base (not shown) and is placed in a common gas-tight casing 55 handled by the turbocharger.
• the motor-compressor unit 44 can include any number of such impellers, or, as will be described later, include another arrangement of impellers.
• the casing is composed of an assembly of integral casing elements such as 55a and 55b, each providing support and protection for the engine or a compression stage, and secured by suitable fixing means.
• the compressor shaft 44 revolves in bearings 55 and
• an axial stop 62 integral with the driven shaft is disposed between two fixed bearings 66 and 68, so as to limit the axial overshoot of the driven shaft 54 of the compressor stage 44, together with an axial aerodynamic balancing piston 70.
• a flexible coupling 72 ensures the coupling of the rotor 38 of the motor 34 and of the driven shaft 54 of the compressor stage 44.
• Such a coupling 72 can be produced either from a coupling of the diaphragm type, or from a flexible blade type coupling, or a twist shaft type coupling.
• any other type of flexible coupling suitable for the intended use can be used.
• the use of a coupling with a twist shaft type makes it possible to reduce losses by ventilation, to reduce the level of noise generated, and to more easily propagate the axial thrust produced by the motor.
• the casing is provided with an orifice 76 which opens facing the junction zone between the rotor 38 and the driven shaft 54. This orifice is associated with a removable waterproof closure device 78
• the entire interior of the turbocharger is bathed in process gas handled by the compressor, including the flexible coupling 72.
• the internal volume of the turbocharger does not have any shaft outlet sealing, but only rotary joints 80 which are subjected to small pressure differences, such as for example labyrinth type rotary joints which are used for the operation of the compressor.
• the engine is left at the suction pressure of the compressor, and a gas circulation is organized to ensure its cooling.
• the radial bearings 40, 42, 55 and 56 used for supporting the rotors do not require a supply of lubricating fluid.
• these bearings are controlled in such a way that they adapt to the dynamic behavior of the rotor or of the driven shaft 54 for which they provide support, that is to say generally rigid on the motor side and generally flexible on the driven shaft side.
• the bearings 40, 42, 55 and 56 are rigidly fixed relative to the casing. These forces consist of the radial weight forces, the dynamic radial forces linked to the residual unbalances, and the axial forces due to the result of aerodynamic thrust on the compression stages.
• These bearings also allow a radial displacement of the rotor or of the driven shaft which they support, in order to allow the lineage of these elements of the line of shafts during the maintenance phases.
• the casing is constituted by an assembly of casing elements respectively providing support for the motor and the compression stage, these casing elements being associated in a rigid and sealed manner.
• Mutually ends opposite 82 and 84 of the casing thus formed are closed, on the one hand by a bolted bottom 86, on which are fixed the bearings 40 of the rotor 38 and, on the other hand, by a second bottom 88 which supports the bearing 56 in which journals the driven shaft 54 and the balancing piston 70, and which is fixed to the casing for example by means of shear rings
• the invention which has just been described, which uses an electric motor and a compressor unit arranged in a sealed common casing and whose shafts respectively leading and driven are secured by means of a flexible coupling arranged in the gas handled by the turbocharger has several advantages.
• each of the rotors, engine and compressor unit retains its own vibrational behavior.
• the rotor of the motor is generally of rigid type, with the first critical speed of bending above the speed of rotation.
• the compressor rotor is generally of the flexible type, with the first critical bending speed below the maximum rotation speed. This avoids creating natural modes of bending coupled between the two rotors which risk developing, during operation, hot spots on the motor rotor, constituting thermal imbalances of phase and of uncontrollable amplitude.
• a flexible coupling also facilitates the positioning of the first natural frequency of torsion, and also contributes to reducing the stress in the shaft end of the compressor in the event of an electrical short circuit at the terminals of the motor. Furthermore, in terms of maintenance, the flexible coupling can be uncoupled from the orifice 76 passing through the casing, and each of the rotor and driven shaft can be extracted while the other continues to be supported by its two bearings. In this way, the rotor and driven shaft are protected during this operation, reassembly being much faster and lineage and dynamic balancing facilitated, due to access to the two central planes on each end of the shaft.
• this is arranged so that the whole rotor-diaphragm assembly can be pulled from the body at the same time as the bottom 88, without having to separate the casing from its base and the piping from process gas. It will be noted that, during these assembly-disassembly phases, the rotors rest on their respective bearings without risk of damage to the rotating parts as well as to the stator parts which could otherwise come into contact with the rotors during these operations.
• a turbocharger is shown provided with a multi-stage compressor integrated in line with a single compression section and with four stages
• the invention also applies to other types of motor-compressors, for example with two sections SI and S2 in line, for example with two stages each, ensuring each of them the compression of a process gas with for example intermediate cooling.
• two inputs E '1 and E'2 and two outputs S' 1 and S'2 are provided in the housing, opposite the input and the output of each of these sections (FIG. 3).
• the first compression stage of one of the sections S2 can be arranged opposite the second compression stage of the other section SI.
• FIG. 3 the first compression stage of one of the sections S2 can be arranged opposite the second compression stage of the other section SI.
• each of the compression bodies has gas extraction means, or reinjection devices, which then considerably increases the number of possible combinations of arrangements.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Electromagnetism (AREA)
• Structures Of Non-Positive Displacement Pumps (AREA)
• Supercharger (AREA)
• Applications Or Details Of Rotary Compressors (AREA)
• Rotary Pumps (AREA)
• Medicines Containing Plant Substances (AREA)

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Applications Claiming Priority (1)

Publications (3)

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Family Applications (1)

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• 2003
  • 2003-03-10 WO PCT/FR2003/000768 patent/WO2004083644A1/fr not_active Ceased
  • 2003-03-10 ES ES03727579.9T patent/ES2586658T3/es not_active Expired - Lifetime
  • 2003-03-10 AU AU2003233369A patent/AU2003233369A1/en not_active Abandoned
  • 2003-03-10 HU HUE03727579A patent/HUE029908T2/hu unknown
  • 2003-03-10 SI SI200332488A patent/SI1604115T1/sl unknown
  • 2003-03-10 EP EP03727579.9A patent/EP1604115B8/de not_active Expired - Lifetime
  • 2003-04-11 US US10/411,239 patent/US7144226B2/en not_active Expired - Lifetime
• 2005
  • 2005-09-09 NO NO20054198A patent/NO339342B1/no not_active IP Right Cessation
• 2016
  • 2016-08-08 CY CY20161100774T patent/CY1117875T1/el unknown

Non-Patent Citations (1)

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