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
  • 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
• • 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
  • F04D29/059—Roller bearings
• • 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
  • F04D29/40—Casings; Connections of working fluid
  • F04D29/42—Casings; Connections of working fluid for radial or helico-centrifugal pumps
  • F04D29/4206—Casings; Connections of working fluid for radial or helico-centrifugal pumps especially adapted for elastic fluid pumps
• • 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
  • F04D29/58—Cooling; Heating; Diminishing heat transfer
  • F04D29/582—Cooling; Heating; Diminishing heat transfer specially adapted for elastic fluid pumps
  • F04D29/5853—Cooling; Heating; Diminishing heat transfer specially adapted for elastic fluid pumps heat insulation or conduction
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
  • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
  • F05D2240/00—Components
  • F05D2240/10—Stators
  • F05D2240/15—Heat shield
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
  • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
  • F05D2260/00—Function
  • F05D2260/20—Heat transfer, e.g. cooling
  • F05D2260/231—Preventing heat transfer

Definitions

• the present invention relates to the field of electric compressors, and more particularly to an electric supercharging compressor comprising a thermal protection system for bearings.
• an electric compressor is a device used to supercharge a heat engine, operating with an electric motor. More specifically, the compressor comprises a compressor wheel driven by an electric motor.
• the electric compressor is placed on the air intake line of an internal combustion engine, in addition for example a turbocharger.
• the electric compressor plays the same role as the turbocharger, namely increase the intake pressure of the fresh gases in the engine, but is used in particular during transient phases to overcome turbocharger response time problems.
• electric superchargers are equipped with two bearings. At least one of the two bearings is located just behind the compressor wheel. It is thus directly exposed to the temperature that can reach the gases admitted to the compressor.
• the bearings used are particularly sensitive to temperature, in particular by their lubrication by grease.
• the present invention therefore aims to overcome one or more of the disadvantages of the devices of the prior art by providing an electric compressor whose front bearing is protected from high temperatures.
• the present invention proposes an electric compressor comprising a shaft driven in rotation by an electric motor via at least one bearing, the shaft driving a compressor wheel in rotation, the bearing being disposed between the electric motor and the compressor wheel, the compressor having a thermal protection system for at least one bearing.
• Such a protection system protects the bearing before high temperatures, of the order of 230 ° C, generated by the flow of air flowing at the wheel.
• the protection system is disposed between a compressor body and the wheel.
• the protection system is an insulating material, that is to say with low thermal conduction.
• the protection system has a thermal conductivity of less than 1 W / (m.K).
• the material is fixed on the compressor body, for example by gluing.
• the protection system is formed by an air gap formed between the compressor body and the wheel.
• the air gap is formed directly between the compressor body and a rear face of the wheel.
• the air gap is formed between the compressor body and an additional piece, for example a heat shield.
• the additional piece has at least one zone in contact with the body of the compressor.
• the thickness of the air gap is between 0.5 and 4 mm.
• the invention also relates to a compressor according to the invention, the compressor being an electric supercharging compressor of a heat engine, and comprising an electric motor with variable reluctance or permanent magnets.
• FIG. 1 is a schematic representation of a sectional view of a portion of a compressor incorporating a system according to a first embodiment of the invention
• FIG. 2 is a schematic representation of a sectional view of a part of a compressor incorporating a system according to a second variant embodiment of the invention
• FIG. 3 is a schematic representation of a sectional view of a portion of a compressor incorporating a system according to an aspect of a first embodiment of the invention of the second variant.
• FIG. 4 is a schematic representation of a sectional view of a portion of a compressor incorporating a system according to another aspect of a first embodiment of the invention of the second variant ..
• the present invention relates to an electric compressor equipped with a bearing protection system.
• the term electric compressor an air compressor, volumetric or not and for example centrifugal or radial, driven by an electric motor, for the purpose of supercharging a heat engine.
• the electric motor is a DC or AC asynchronous motor.
• the electric motor is a variable reluctance motor (also called SRM machine for Switched Reluctance Motor according to English terminology).
• the electric motor is a permanent magnet motor.
• the electric compressor 1, illustrated in FIG. 1, comprises a non-illustrated electric motor arranged in a motor compartment, and at least one bearing 7 arranged circularly around the shaft 6.
• the compressor 1 comprises two bearings 7 of which at least one, called in the following description bearing 7 before, is arranged between the electric motor and a wheel 3 of compressor.
• the compressor wheel 3 is disposed in a compression compartment delimited by a rear face 31 of the wheel 3.
• the electric motor allows the rotation of the shaft 6 of the electric compressor via at least one bearing 7.
• the shaft 6 thus causes the wheel 3 of the compressor 1, disposed at one end of the shaft 6, to be rotated. More precisely, one end of the shaft 6 is rotated by the electric motor, and another end of the shaft 6 drives rotation the wheel 3 of the compressor.
• the intermediate portion of the shaft is protected by the compressor body 8.
• This compressor body 8 comprises the bearings. More specifically, part
• the compressor body 8 extends between the front bearing 7 and the compartment of the compressor wheel 3.
• the front bearing 7 is thus disposed in the compressor body 8.
• This body portion 8 of the compressor is not sufficient to protect the bearing 7 before high temperatures, of the order of 230 ° C, generated by the flow of air flowing at the wheel 3.
• the invention therefore provides a system 41, 42, 43 of thermal protection for at least one bearing 7 before.
• the protection system 41, 42, 43 is disposed between the body 8 of the compressor and the wheel 3. More specifically, the system 41, 42, 43 of thermal protection is disposed between the extension 81 of the compressor body 8 and the compartment of the compressor. compression delimited by the rear face 31 of the wheel 3.
• the protection system is formed by the addition of an insulating material 41, that is to say of low heat conduction.
• low thermal conduction is meant a thermal conductivity at least 100 times less than that of the material making up the body 8, more precisely less than 1 W / (mK).
• this material is fixed on the compressor body, for example by gluing.
• the material 41 is fixed on the body 8 of the compressor, more precisely on the extension 81 of the compressor body 8, between this extension 81 and the compressor wheel 3.
• the insulating material 41 is made of plastic, glass wool or rock. Its thickness is less than 5mm. The use of plastic is an economical solution within the scope of the invention.
• the protection system 43 is formed by an air gap 43 formed between the body 8 of the compressor and the wheel 3, and more specifically the rear face 31 of the wheel 3.
• the air gap 43 is formed directly between the body 8 of the compressor and the rear face 31 of the wheel 3, and for example in a housing dug for this purpose.
• the air gap 43 is formed between the body 8 of the compressor and an additional piece 42.
• This additional piece 42 is for example a heat shield formed for example of a piece of steel or stainless steel stamped or obtained by machining.
• This piece is for example a plate.
• the additional piece or heat shield 42 has at least a first zone 810 in contact with the body 8 of the compressor.
• the heat shield 42 has for example the form of an annular plate whose outer end 421 is curved and forms a rounded or square S. It is for example this curved end 421 which is in contact with the body 8 of the compressor, and more precisely with the extension 81 of the compressor body 8.
• This aspect of the invention has the advantage of limiting the transfer of heat to the body 8 by conduction between the heat shield 42 and the extension 81 of the body 8, these two parts being in good heat conducting materials.
• the radial clearance between the heat shield 42 and the shaft 6 is limited to a few tenths of a millimeter. This limitation of the play, contributes to the effectiveness of the thermal protection of the bearing 7.
• the additional part or heat shield 42 has at least a first and second zone 810, 820 in contact with the body 8 of the compressor.
• the heat shield 42 has for example, the shape of an annular plate whose ends 421 and 422 interior are curved and form a rounded S or square, or a stop. These are for example those curved ends 421, 422 which are in contact with the body 8 of the compressor, and more specifically with the extension 81 of the compressor body 8.
• This aspect of the invention has the advantage of completely enclosing the air gap 43, thus avoiding any recirculation of the air.
• the contact at the first zone 810 is for example made by screwing, gluing, welding, fitting or clipping.
• the second contact zone is formed by guiding or fitting on a prolonged part of the body (not shown).
• the thickness of the air gap 43 is between 0.5 and 4 mm, and for example is equal to 1.5 mm, the effectiveness of the insulation being directly related to the thickness. Indeed, the greater the thickness of the blade, the greater the insulation.
• the heat shield 42 also has the advantage of reducing the heat input by radiation.
• the compressor according to the invention is thus configured so as to thermally protect the bearings against heat coming from the air admitted at the level of the compressor wheel.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Structures Of Non-Positive Displacement Pumps (AREA)
• Applications Or Details Of Rotary Compressors (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=55863082

Family Applications (1)

Country Status (3)

Citations (1)

Family Cites Families (4)

• 2016
  • 2016-03-22 FR FR1652431A patent/FR3049661B1/fr active Active
• 2017
  • 2017-03-20 WO PCT/FR2017/050641 patent/WO2017162969A1/fr active Application Filing
  • 2017-03-20 EP EP17716954.7A patent/EP3433497A1/de not_active Withdrawn

Patent Citations (1)

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