US20040052660A1 - Electric compressor - Google Patents
Electric compressor Download PDFInfo
- Publication number
- US20040052660A1 US20040052660A1 US10/619,041 US61904103A US2004052660A1 US 20040052660 A1 US20040052660 A1 US 20040052660A1 US 61904103 A US61904103 A US 61904103A US 2004052660 A1 US2004052660 A1 US 2004052660A1
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- United States
- Prior art keywords
- switching device
- electric compressor
- groove
- housing
- wall
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
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Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C29/00—Component parts, details or accessories of pumps or pumping installations, not provided for in groups F04C18/00 - F04C28/00
- F04C29/04—Heating; Cooling; Heat insulation
- F04C29/047—Cooling of electronic devices installed inside the pump housing, e.g. inverters
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01C—ROTARY-PISTON OR OSCILLATING-PISTON MACHINES OR ENGINES
- F01C21/00—Component parts, details or accessories not provided for in groups F01C1/00 - F01C20/00
- F01C21/10—Outer members for co-operation with rotary pistons; Casings
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B35/00—Piston pumps specially adapted for elastic fluids and characterised by the driving means to their working members, or by combination with, or adaptation to, specific driving engines or motors, not otherwise provided for
- F04B35/04—Piston pumps specially adapted for elastic fluids and characterised by the driving means to their working members, or by combination with, or adaptation to, specific driving engines or motors, not otherwise provided for the means being electric
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B39/00—Component parts, details, or accessories, of pumps or pumping systems specially adapted for elastic fluids, not otherwise provided for in, or of interest apart from, groups F04B25/00 - F04B37/00
- F04B39/12—Casings; Cylinders; Cylinder heads; Fluid connections
- F04B39/121—Casings
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C18/00—Rotary-piston pumps specially adapted for elastic fluids
- F04C18/02—Rotary-piston pumps specially adapted for elastic fluids of arcuate-engagement type, i.e. with circular translatory movement of co-operating members, each member having the same number of teeth or tooth-equivalents
- F04C18/0207—Rotary-piston pumps specially adapted for elastic fluids of arcuate-engagement type, i.e. with circular translatory movement of co-operating members, each member having the same number of teeth or tooth-equivalents both members having co-operating elements in spiral form
- F04C18/0215—Rotary-piston pumps specially adapted for elastic fluids of arcuate-engagement type, i.e. with circular translatory movement of co-operating members, each member having the same number of teeth or tooth-equivalents both members having co-operating elements in spiral form where only one member is moving
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C23/00—Combinations of two or more pumps, each being of rotary-piston or oscillating-piston type, specially adapted for elastic fluids; Pumping installations specially adapted for elastic fluids; Multi-stage pumps specially adapted for elastic fluids
- F04C23/008—Hermetic pumps
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C2240/00—Components
- F04C2240/80—Other components
- F04C2240/808—Electronic circuits (e.g. inverters) installed inside the machine
Definitions
- the present invention relates to an electric compressor for a refrigeration cycle used in an automotive air conditioner to compress a refrigerant.
- Japanese Laid-Open Utility Model Publication No. 62-12471 and Japanese Laid-Open Patent Publication No. 2002-5024 each describe an electric compressor having an inverter, which drives an electric motor, attached to an outer surface of a compressor housing, which houses a compression mechanism.
- the low temperature refrigerant flowing through the electric compressor exchanges heat with a switching device, which forms the inverter, through the compressor housing.
- a mechanism for cooling the inverter such as a radiator or a fan, is not required.
- Japanese Utility Model Publication No. 62-12471 only describes that the switching device is attached to, or contacts, the outer surface of the electric compressor housing. There is no disclosure of how to improve the heat exchange efficiency between the compressor housing and the switching device.
- the present invention provides an electric compressor for use in a refrigeration circuit.
- the electric compressor includes a housing having an outer surface, an electric motor, and a compression mechanism accommodated in the housing for being driven by the electric motor.
- An inverter is attached to the outer surface of the housing to drive the electric motor.
- the inverter includes a switching device having a heat radiating surface.
- a groove having a wall is formed in the outer surface of the housing. The switching device is inserted in the groove so that the heat radiating surface contacts the wall of the groove.
- a further aspect of the present invention is an electric compressor including a housing having a cylindrical wall with an outer surface and an axis, an electric motor, and a compression mechanism accommodated in the housing. When operated, the compression mechanism is driven by the electric motor.
- An inverter is attached to the outer surface of the cylindrical wall to drive the electric motor.
- the inverter includes a plurality of cylindrical electrolysis capacitors, each having an axis. The axes of the electrolysis capacitors are parallel to one another and parallel to the axis of the cylindrical wall.
- FIG. 1 is a cross-sectional view of an electric compressor according to a preferred embodiment of the present invention
- FIG. 2 is a side view showing the electric compressor
- FIG. 3 is a cross-sectional view taken along line 3 - 3 in FIG. 2;
- FIG. 4 is an exploded perspective view showing a switching device assembly of the electric compressor
- FIG. 5 is an exploded perspective view showing electrolysis capacitors of the electric compressor
- FIG. 6 is a cross-sectional view of a switching device assembly in another embodiment of the present invention.
- FIG. 7 is a cross-sectional view of a switching device assembly in a further embodiment of the present invention.
- FIGS. 1 to 5 An electric compressor 10 according to a preferred embodiment of the present invention will now be discussed with reference to FIGS. 1 to 5 .
- the electric compressor 10 is incorporated in a refrigeration cycle of an automotive air conditioner.
- the electric compressor 10 has a compressor housing 11 including a first housing member 21 and a second housing member 22 .
- the first housing member 21 which is an aluminum alloy casting, has a cylindrical wall 23 .
- the second housing member 22 is also an aluminum alloy casting.
- the first housing member 21 and the second housing member 22 are coupled to each other to define a hollow portion 24 in the compressor housing 11 .
- a rotary shaft 27 is rotatably supported in the first housing member 21 .
- An axis L of the rotary shaft 27 coincides with an axis of the electric compressor 10 .
- the cylindrical wall 23 extends around the rotary shaft 27 so that the axis of the cylindrical wall 23 coincides with the axis L of the rotary shaft 27 .
- the electric motor 25 and a compression mechanism 26 are accommodated in the hollow portion 24 .
- the electric motor 25 includes a stator 25 a , which is fixed to an inner surface 23 a of the cylindrical wall 23 , and a rotor 25 b , which is arranged on the rotary shaft 27 radially inward from the stator 25 a .
- the electric motor 25 rotates the rotary shaft 27 with power supplied from the stator 25 a.
- the first housing member 21 has a suction port 31 .
- the second housing member 22 has a discharge port 32 .
- An external refrigeration circuit 61 which includes a condenser 62 , an expansion valve 63 , and an evaporator 64 , connect the suction port 31 and the discharge port 32 .
- the external refrigeration circuit 61 and the electric compressor 10 form the refrigeration cycle of the automotive air conditioner.
- the compression mechanism 26 includes a fixed scroll 26 a and a movable scroll 26 b .
- the movable scroll 26 b orbits relative to the fixed scroll 26 a to compress refrigerant gas.
- the electric motor 25 drives the compression mechanism 26
- low temperature, low pressure refrigerant gas is drawn into the compression mechanism 26 from the evaporator 64 through the suction port 31 .
- the compression mechanism 26 compresses the drawn refrigerant gas to produce high temperature, high pressure refrigerant gas and sends the refrigerant gas to the condenser 62 through the discharge port 32 .
- the first housing member 21 includes a retainer 36 projecting from a part of the outer surface 23 b of the cylindrical wall 23 .
- the retainer 36 includes side walls 37 , which extend integrally from the outer surface 23 b of the cylindrical wall 23 , and a cover 38 , which is fixed to the top of the side walls 37 to cover the opening of the side walls 37 .
- a retaining chamber 35 is defined in the retainer 36 .
- the retaining chamber 35 has a bottom surface 35 a , which is part of the outer surface 23 b of the cylindrical wall 23 .
- the retaining chamber 35 also has side surfaces 35 b , which are the inner surfaces of the side walls 37 .
- the bottom surface 35 a and side surfaces 35 b of the retaining chamber 35 are defined by parts of the first housing member 21 .
- the bottom surface 35 a in the retainer 36 is curved along the cylindrical wall 23 .
- the retaining chamber 35 further has a top surface 35 c , which is the inner surface of the cover 38 .
- the distance between the bottom surface 35 a and the top surface 35 c decreases at the middle section of the retaining chamber 35 and increases at the peripheral sections on each side (left and right sides as viewed in FIG. 3) of the retaining chamber 35 .
- An inverter 41 which drives the electric motor 25 , is retained in the retainer 36 .
- the inverter 41 supplies the stator 25 a of the electric motor 25 with power in accordance with a command from an air conditioner ECU (not shown).
- the inverter 41 includes a first circuit board 42 and a second circuit board 43 , which are for use in a power system, and a third circuit board 44 , which is for use in a control system.
- a switching device assembly 70 , a capacitor 46 , and electric components of the power system that configure an inverter circuit (not shown), such as a transformer, are connected to the first circuit board 42 .
- the switching device assembly 70 includes a plurality of switching devices 45 (six in the preferred embodiment).
- a plurality of electrolysis capacitors 47 (five in the preferred embodiment), which are electric components of the power system configuring the inverter circuit, are mounted on the plane 43 a of the second circuit board 43 .
- the electrolysis capacitors 47 are cylindrical and configure a smoothening circuit.
- the smoothening circuit stabilizes the battery voltage applied to a power system circuit of the inverter 41 .
- the electrolysis capacitors 47 occupy much space in the retaining chamber 35 .
- the second circuit board 43 is separated from the first circuit board 42 to efficiently use the limited space in the retaining chamber 35 of the retainer 36 .
- a driver 48 mounted on the third circuit board 44 intermittently controls the switching devices 45 in accordance with commands from, for example, the air conditioner ECU.
- relatively large electric components such as the switching device assembly 70 and the capacitor 46 are connected to the lower surface 42 a of the first circuit board 42 .
- the lower surface 42 a of the first circuit board 42 faces towards the bottom surface 35 a of the retaining chamber 35 .
- the third circuit board 44 is arranged between the first circuit board 42 and the cover 38 in the retainer 36 .
- the first circuit board 42 and the third circuit board 44 are arranged in the retainer 36 in a superimposed manner.
- the first circuit board 42 is fixed to the compressor housing 11 by bolts (not shown).
- the third circuit board 44 is fixed to the first circuit board 42 by bolts (not shown).
- Resin molding such as insert molding, is performed to integrate the six switching devices 45 into the switching device assembly 70 .
- Resin molding is performed by arranging the switching devices 45 in two rows and filling connecting resin 57 into the space between the switching devices 45 so as to connect the switching devices 45 .
- the six switching devices 45 of the switching device assembly 70 each include a body 45 a and three terminals 45 b extending from one end of the body 45 a . Among the three terminals 45 b , two are bent. The remaining terminal 45 b extends straight from the end of the body 45 a . Due to such configuration, the wiring pattern (not shown) of the circuit board 42 , to which the distal portions of the terminals 45 b are connected, is not dense.
- the six switching devices 45 are arranged in two rows in the longitudinal direction of the switching device assembly 70 .
- the bent terminals 45 b of the switching devices 45 in each row are aligned in the longitudinal direction.
- the straight terminal 45 b is arranged between the bent terminals 45 b in each switching device 45 .
- the switching device assembly 70 is the component that projects the most from the first circuit board 42 . If a component projecting from the first circuit board 42 is arranged in the central portion of the retainer 36 where the distance between the bottom surface 35 a and the top surface 35 c of the retaining chamber 35 is small, the distance between the lower surface 42 a of the first circuit board 42 and the outer surface of the cylindrical wall 23 must be increased. This enlarges the retainer 36 , which in turn, enlarges the electric compressor 10 in the radial direction (i.e., the direction perpendicular to the axis L).
- the switching device assembly 70 is connected to the first circuit board 42 at the peripheral section (left side as viewed in FIG. 3) where the distance between the bottom surface 35 a and the top surface 35 c of the retaining chamber 35 is large.
- Such arrangement of the switching device assembly 70 enables the first circuit board 42 to be positioned near the cylindrical wall 23 .
- the size of the retainer 36 may be reduced, and the electric compressor 10 may be made more compact.
- the arrangement of the switching device assembly 70 which is a projecting component, in one side of the retaining chamber 35 provides a relatively large space from the middle portion of the retaining chamber 35 to the other side (right side as viewed in FIG. 3) of the retaining chamber 35 between the first circuit board 42 and the bottom surface 35 a of the retaining chamber 35 .
- the electrolysis capacitors 47 which occupy much space, are arranged in a row in the circumferential direction of the cylindrical wall 23 . Accordingly, the layout of the switching device assembly 70 in one side of the retainer 36 not only enables the size of the electric compressor 10 to be reduced in the radial direction but also enables efficient usage of the space in the retainer 36 .
- the plane 43 a of the second circuit board 43 is perpendicular to the axis L of the compressor housing 11 .
- the axes of the parallel electrolysis capacitors 47 are parallel to the axis L of the compressor housing 11 .
- the second circuit board 43 has a flat surface and a bent portion at the middle in correspondence with the bottom surface 35 a of the retaining chamber 35 .
- the five electrolysis capacitors 47 are connected to the second circuit board 43 in a manner forming a line that is bent at the middle so as to follow the curve of the bottom surface 35 a.
- a resin capacitor holder 49 fixes the five electrolysis capacitors 47 to the compressor housing 11 .
- the capacitor holder 49 has five holding portions 49 a to hold the five electrolysis capacitors 47 .
- the capacitor holder 49 is formed so that the line defined by the holding portions 49 a is bent at the middle in accordance with the bent line of the electrolysis capacitors 47 .
- the capacitor holder 49 is fastened to the compressor housing 11 by bolts 60 (refer to FIG. 5). This holds the electrolysis capacitors 47 between the capacitor holder 49 and the bottom surface 35 a of the retaining chamber 35 .
- a resin sheet 50 is arranged on the bottom surface 35 a of the retaining chamber 35 to separate the bottom surface 35 a from the capacitor 46 and the electrolysis capacitors 47 .
- the sheet 50 may be made of rubber as long as it has superior elastic and heat conducting properties. That is, the capacitor 46 and the electrolysis capacitors 47 indirectly contact the bottom surface 35 a of the retaining chamber 35 by means of the sheet 50 .
- a groove 51 is formed in the outer surface 23 b of the cylindrical wall 23 of the compressor housing 11 in the retaining chamber 35 . More specifically, a first wall 52 and a second wall 53 , which are parallel to the axis L, define the groove 51 .
- the side wall 37 of the retainer 36 that is located near the switching device 45 serves as the first wall 52 .
- the second wall 53 is extended from the outer surface 23 b of the cylindrical wall 23 in the retainer 36 .
- a part of the outer surface 23 b of the cylindrical wall 23 (bottom surface 35 a of the retaining chamber 35 ) functions as a bottom surface 51 a of the groove 51 , which connects the first wall 52 and the second wall 53 .
- an inner surface 52 a of the first wall 52 faces towards an inner surface 53 a of the second wall 53 in the groove 51 .
- the inner surfaces 52 a and 53 a of the first and second walls 52 and 53 are inclined relative to a vertical line S, which is perpendicular to a horizontal plane extending through the axis L of the rotary shaft 27 as viewed in FIG. 3.
- the switching devices 45 each have a heat radiating surface 45 c , which is faced to the associated inner surface 52 a or 53 a of the groove 51 .
- the switching device assembly 70 has six heat radiating surfaces 45 c , three on each side of the switching device assembly 70 (FIG. 4).
- the heat radiating surface 45 c is the surface of the body 45 a from which a conducting portion of a transistor, which forms the switching device 45 , is exposed.
- the conducting portion is encircled in each heat radiating surface 45 c in FIG. 4.
- each switching device 45 contacts the corresponding inner surface 52 a or 53 a of the groove 51 . More specifically, in the row of the three switching devices 45 that are closer to the first wall 52 , the heat radiating surfaces 45 c contact the inner surface 52 a of the first wall 52 . Further, in the row of the three switching devices 45 that are closer to the second wall 53 , the heat radiating surfaces 45 c contact the inner surface 53 a of the second wall 53 .
- An elastic sheet 54 is arranged between the heat radiating surfaces 45 c of the switching devices 45 and the inner surfaces 52 a and 53 a of the groove 51 .
- the elastic sheet 54 is made of rubber or resin. Further, the sheet 54 has a superior heat conducting property.
- a flat fastening plate 55 is fixed to the compressor housing 11 to cover the opening of the groove 51 .
- the fastening plate 55 functions as a fastening member and a pressure applying body.
- the lower surface of the fastening plate 55 presses the switching device assembly 70 in a direction parallel to the vertical line S.
- the heat radiating surfaces 45 c of the switching device 45 and the inner surfaces 52 a and 53 a of the groove 51 are inclined relative to the vertical line S. Accordingly, when the fastening plate 55 presses the switching device assembly 70 in the direction parallel to the vertical line S, the heat radiating surfaces 45 c of the switching devices 45 are pressed strongly against the inner surfaces 52 a and 53 a of the groove 51 through the sheet 54 .
- the fastening plate 55 functions to press the switching devices 45 against the inner surfaces 52 a and 53 a of the groove 51 .
- a plurality of insertion holes 55 a are extend through the fastening plate 55 .
- the terminals 45 b of the switching devices 45 are inserted through the corresponding insertion holes 55 a .
- the fastening plate 55 is fastened to the compressor housing 11 by bolts 58 .
- the terminals 45 b projecting out of the insertion holes 55 a of the fastening plate 55 are soldered.
- a refrigerant gas passage 33 connecting the suction port 31 to the compression mechanism 26 passes by the groove 51 in the compressor housing 11 . More specifically, the refrigerant gas passage 33 is defined between the inner surface 23 a of the cylindrical wall 23 and the outer surface of the stator 25 a of the electric motor 25 at a location corresponding to the groove 51 . The refrigerant gas passage 33 extends parallel to the axis L of the rotary shaft 27 .
- Heat exchange between the switching devices 45 and the cooler cylindrical wall 23 is performed mainly at locations where the heat radiating surfaces 45 c of the switching devices 45 contact the corresponding inner surfaces 52 a and 53 a of the groove 51 .
- the groove 51 is formed in the outer surface 23 b of the compressor housing 11 .
- the bottom surface 51 a and inner surfaces 52 a and 53 a of the groove 51 are provided by the compressor housing 11 , the temperature of which is low. Accordingly, the compressor housing 11 cools the switching devices 45 more easily in comparison to, for example, when the switching devices 45 are arranged outside the groove 51 . This improves the heat exchange efficiency between the switching device 45 and the compressor housing 11 in comparison to the heat exchange described in, for example, Japanese Laid-Open Utility Model Publication No. 62-12471. Further, this cools the inverter 41 in a preferable manner, improves the durability of the inverter 41 , and stabilizes the operation of the inverter 41 .
- the switching device assembly 70 which is formed from the unit of the switching devices 45 , is inserted in the groove 51 . Accordingly, the switching devices 45 are inserted in the groove 51 at the same time by inserting the switching device assembly 70 . This simplifies assembly of the electric compressor 10 .
- the inner surfaces 52 a and 53 a of the groove 51 are inclined relative to the vertical line S of the groove 51 so that the distance between the inner surfaces 52 a and 53 a of the groove 51 decreases as the bottom surface 51 a of the groove 51 becomes closer. Accordingly, the heat radiating surfaces 45 c of the switching devices 45 come into close contact with the corresponding inner surfaces 52 a and 53 a of the groove 51 as if a wedge is inserted into the compressor housing 11 . This further improves heat exchange efficiency between the switching device 45 and the compressor housing 11 .
- the elastic sheet 54 is arranged between the heat radiating surfaces 45 c of the switching devices 45 and the corresponding inner surfaces 52 a and 53 a of the groove 51 . Accordingly, elastic deformation of the sheet 54 absorbs dimensional differences and increases contact between the heat radiating surfaces 45 c of the switching devices 45 and the corresponding inner surfaces 52 a and 53 a of the groove 51 . Further, the superior heat conductance of the sheet 54 further improves the heat exchange efficiency between the switching devices 45 and the compressor housing 11 . The elastic sheet 54 also protects the switching devices 45 from impacts, or the like, applied to the compressor housing 11 .
- the refrigerant gas passage 33 which connects the low pressure side of the external refrigeration circuit 61 (the side in which the evaporator 64 is located) to the compression mechanism 26 , passes by the groove 51 . Accordingly, the low temperature refrigerant gas that passes by the groove 51 effectively cools the switching devices 45 .
- the inverter 41 is retained in the retaining chamber 35 of the compressor housing 11 .
- the bottom surface 35 a and side surface 35 b of the retaining chamber 35 are part of the compressor housing 11 . This reduces the number of components in comparison to when preparing a retainer separately from the compressor housing 11 (e.g., when retaining the inverter 41 in a case and attaching the case to the compressor housing 11 ).
- the inverter 41 is surrounded by the compressor housing 11 , which has high rigidity. This is effective for protecting the inverter from external impacts.
- the elastic sheet 50 separates the electrolysis capacitors 47 and the capacitor 46 from the bottom surface 35 a of the retaining chamber 35 . Accordingly, elastic deformation of the sheet 50 absorbs dimensional differences and increases contact of the electrolysis capacitors 47 and the capacitor 46 against the bottom surface 35 a of the retaining chamber 35 . Further, the superior heat conductance of the sheet 50 further improves the heat exchange efficiency of the capacitors 46 and 47 with the compressor housing 11 .
- the elastic sheet 50 also protects the capacitors 46 and 47 from impacts, or the like, applied to the compressor housing 11 .
- the switching device assembly 70 is connected to the first circuit board 42 after arranging the switching device assembly 70 in the groove 51 . Accordingly, by adjusting the insertion of the terminals 45 b of the switching devices 45 for the first circuit board 42 , dimensional differences of each portion is absorbed and the heat radiating surfaces 45 c of the switching devices 45 come into close contact with the corresponding inner surfaces 52 a and 53 a of the groove 51 . This further improves heat exchange efficiency between the switching devices 45 and the compressor housing 11 .
- the axes M of the electrolysis capacitors 47 are parallel to each other and to the axis L of the rotary shaft 27 (cylindrical wall 23 ).
- the projecting height of the inverter 41 (retainer 36 ) from the cylindrical wall 23 is decreased.
- the electric compressor 10 does not have to be enlarged in the radial direction.
- the electrolysis capacitors 47 are arranged in a row along the outer surface 23 b of the cylindrical wall 23 . Accordingly, in comparison to, for example, when arranging the electrolysis capacitors 47 in a stacked manner, the projecting height of the inverter 41 (retainer 36 ) from the cylindrical wall 23 is decreased.
- the electrolysis capacitors 47 are held between the capacitor holder 49 and the cylindrical wall 23 .
- the capacitor holder 49 fixes the electrolysis capacitors 47 to the compressor housing 11 .
- the fastening of the electrolysis capacitors 47 to the compressor housing 11 is guaranteed. This improves vibration resistance of the electrolysis capacitors 47 .
- the electric compressor 10 of the preferred embodiment is especially desirable under harsh vibration conditions, such as in an automobile.
- the electrolysis capacitors 47 are connected to the second circuit board 43 , which is separated from the first circuit board 42 .
- freedom of layout for the second circuit board 43 increases in the compressor housing 11 .
- freedom of layout for the electrolysis capacitors 47 increases.
- the electrolysis capacitors 47 are arranged between the first circuit board 42 and the cylindrical wall 23 . Due to the difference in the shapes of the first circuit board 42 , which is flat, and the cylindrical wall 23 , which is curved, it is difficult to arrange electric components in the space between the first circuit board 42 and the cylindrical wall 23 . However, in the preferred embodiment, the electrolysis capacitors 47 are arranged in the space in an orderly manner along the outer surface 23 b of the cylindrical wall 23 . The layout of the electrolysis capacitors 47 in the space between the first circuit board 42 and the cylindrical wall 23 , which would otherwise be dead space, is extremely effective for decreasing the height that the inverter 41 projects from the cylindrical wall 23 .
- the groove 51 may be formed so that its opposing inner surfaces 52 a and 53 a are parallel to each other.
- the heat radiating surfaces 45 c of the switching devices 45 in the switching device assembly 71 are parallel to the vertical line S.
- a third wall 59 may be arranged between the first wall 52 and the second wall 53 .
- the compressor housing 11 has two grooves 51 .
- Three of the switching devices 45 are arranged in each of the grooves 51 .
- a switching device assembly 72 which is formed by integrating three switching devices 45 A into a switching device assembly 72 with resin, is inserted in each groove 51 .
- the sheet 54 arranged between the heat radiating surfaces 45 c of the switching devices 45 and the inner surfaces 52 a and 53 a of the groove 51 may be eliminated. Further, the heat radiating surfaces 45 c of the switching devices 45 may come into direct contact with the corresponding inner surfaces 52 a and 53 a of the groove 51 .
- the row of the electrolysis capacitors 47 may be linear.
- the electrolysis capacitors 47 may be stacked upon one another.
- the capacitor holder 49 may be eliminated, and the second circuit board 43 may be fixed to the compressor housing 11 or the other circuit boards 42 or 44 by bolts.
- the electrolysis capacitors 47 may be indirectly connected to the compressor housing 11 through the second circuit board 43 . This would decrease the number of components.
- the second circuit board 43 may be eliminated and wires may be connected directly to the electrolysis capacitors 47 .
- the electrolysis capacitors 47 may easily be attached to the compressor housing 11 .
- the electrolysis capacitors 47 may be arranged on the plane on the other side of the second circuit board 43 .
- the present invention may be applied to an electric compressor in which the electric motor is separated from the compression mechanism.
- the inverter is arranged in the compressor housing, which accommodates the compression mechanism.
- the present invention may be applied to an electric compressor in which the electric motor and compression mechanisms are arranged in different compressor housings.
- the inverter may be arranged in the compressor housing accommodating the electric motor or in the compressor housing accommodating the compression mechanism.
- the present invention may be embodied in a so-called hybrid compressor, which uses an automotive drive source, or an engine, as another compressor drive source.
- the compression mechanism 26 does not have to be a scroll type mechanism and may be a piston type, vane type, or helical type mechanism.
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- Engineering & Computer Science (AREA)
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- General Engineering & Computer Science (AREA)
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Abstract
An electric compressor that is compact and efficiently exchanges the heat arisen by its inverter. The compressor includes a housing, an electric motor, and a compression mechanism accommodated in the housing. The compression mechanism is driven by the electric motor to compress a refrigerant. The inverter is attached to the outer surface of the housing to drive the electric motor. The inverter includes a switching device having a heat radiating surface. A groove is formed in the outer surface of the housing. The switching device is inserted in the groove so that the heat radiating surface contacts the wall of the groove to efficiently exchange heat with the compressor housing.
Description
- The present invention relates to an electric compressor for a refrigeration cycle used in an automotive air conditioner to compress a refrigerant.
- Japanese Laid-Open Utility Model Publication No. 62-12471 and Japanese Laid-Open Patent Publication No. 2002-5024 each describe an electric compressor having an inverter, which drives an electric motor, attached to an outer surface of a compressor housing, which houses a compression mechanism. To cope with the heat generated from the inverter, in Japanese Laid-Open Utility Model Publication No. 62-12471, the low temperature refrigerant flowing through the electric compressor exchanges heat with a switching device, which forms the inverter, through the compressor housing. Such a structure is advantageous in that a mechanism for cooling the inverter, such as a radiator or a fan, is not required.
- However, Japanese Utility Model Publication No. 62-12471 only describes that the switching device is attached to, or contacts, the outer surface of the electric compressor housing. There is no disclosure of how to improve the heat exchange efficiency between the compressor housing and the switching device.
- When the inverter is attached to the compressor, part of the inverter projects outward from the compressor housing. This enlarges the electric compressor. Space is limited when installing the compressor in an automobile. Thus, enlargement of the compressor must be avoided. To keep the electric compressor compact, the height of the part of the inverter projecting from the compressor housing must be lowered. Among the electric components included in the inverter, a plurality of large electrolysis capacitors are used in a smoothening circuit. To lower the height of the projecting part of the inverter, the layout of electrolysis capacitors must be changed. However, in the prior art, sufficient consideration has not been given to the layout of the electrolysis capacitors.
- It is an object of the present invention to provide an electric compressor that is compact and increases the efficiency for exchanging heat between the switching device and the compressor housing.
- To achieve the above object, the present invention provides an electric compressor for use in a refrigeration circuit. The electric compressor includes a housing having an outer surface, an electric motor, and a compression mechanism accommodated in the housing for being driven by the electric motor. An inverter is attached to the outer surface of the housing to drive the electric motor. The inverter includes a switching device having a heat radiating surface. A groove having a wall is formed in the outer surface of the housing. The switching device is inserted in the groove so that the heat radiating surface contacts the wall of the groove.
- A further aspect of the present invention is an electric compressor including a housing having a cylindrical wall with an outer surface and an axis, an electric motor, and a compression mechanism accommodated in the housing. When operated, the compression mechanism is driven by the electric motor. An inverter is attached to the outer surface of the cylindrical wall to drive the electric motor. The inverter includes a plurality of cylindrical electrolysis capacitors, each having an axis. The axes of the electrolysis capacitors are parallel to one another and parallel to the axis of the cylindrical wall.
- Other aspects and advantages of the present invention will become apparent from the following description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention.
- The invention, together with objects and advantages thereof, may best be understood by reference to the following description of the presently preferred embodiments together with the accompanying drawings in which:
- FIG. 1 is a cross-sectional view of an electric compressor according to a preferred embodiment of the present invention;
- FIG. 2 is a side view showing the electric compressor;
- FIG. 3 is a cross-sectional view taken along line3-3 in FIG. 2;
- FIG. 4 is an exploded perspective view showing a switching device assembly of the electric compressor;
- FIG. 5 is an exploded perspective view showing electrolysis capacitors of the electric compressor;
- FIG. 6 is a cross-sectional view of a switching device assembly in another embodiment of the present invention; and
- FIG. 7 is a cross-sectional view of a switching device assembly in a further embodiment of the present invention.
- An
electric compressor 10 according to a preferred embodiment of the present invention will now be discussed with reference to FIGS. 1 to 5. Theelectric compressor 10 is incorporated in a refrigeration cycle of an automotive air conditioner. - Referring to FIGS. 1 and 2, the
electric compressor 10 has acompressor housing 11 including afirst housing member 21 and asecond housing member 22. Thefirst housing member 21, which is an aluminum alloy casting, has acylindrical wall 23. Thesecond housing member 22 is also an aluminum alloy casting. Thefirst housing member 21 and thesecond housing member 22 are coupled to each other to define ahollow portion 24 in thecompressor housing 11. - As shown in FIG. 1, a
rotary shaft 27 is rotatably supported in thefirst housing member 21. An axis L of therotary shaft 27 coincides with an axis of theelectric compressor 10. Thecylindrical wall 23 extends around therotary shaft 27 so that the axis of thecylindrical wall 23 coincides with the axis L of therotary shaft 27. - An
electric motor 25 and acompression mechanism 26 are accommodated in thehollow portion 24. Theelectric motor 25 includes astator 25 a, which is fixed to aninner surface 23 a of thecylindrical wall 23, and arotor 25 b, which is arranged on therotary shaft 27 radially inward from thestator 25 a. Theelectric motor 25 rotates therotary shaft 27 with power supplied from thestator 25 a. - As shown in FIG. 2, the
first housing member 21 has asuction port 31. Thesecond housing member 22 has adischarge port 32. Anexternal refrigeration circuit 61, which includes acondenser 62, an expansion valve 63, and anevaporator 64, connect thesuction port 31 and thedischarge port 32. Theexternal refrigeration circuit 61 and theelectric compressor 10 form the refrigeration cycle of the automotive air conditioner. - As shown in FIG. 1, the
compression mechanism 26 includes afixed scroll 26 a and amovable scroll 26 b. When therotary shaft 27 rotates, themovable scroll 26 b orbits relative to thefixed scroll 26 a to compress refrigerant gas. Accordingly, when theelectric motor 25 drives thecompression mechanism 26, low temperature, low pressure refrigerant gas is drawn into thecompression mechanism 26 from theevaporator 64 through thesuction port 31. Thecompression mechanism 26 compresses the drawn refrigerant gas to produce high temperature, high pressure refrigerant gas and sends the refrigerant gas to thecondenser 62 through thedischarge port 32. - Referring to FIG. 3, the
first housing member 21 includes aretainer 36 projecting from a part of theouter surface 23 b of thecylindrical wall 23. Theretainer 36 includesside walls 37, which extend integrally from theouter surface 23 b of thecylindrical wall 23, and acover 38, which is fixed to the top of theside walls 37 to cover the opening of theside walls 37. Aretaining chamber 35 is defined in theretainer 36. - The
retaining chamber 35 has abottom surface 35 a, which is part of theouter surface 23 b of thecylindrical wall 23. Theretaining chamber 35 also hasside surfaces 35 b, which are the inner surfaces of theside walls 37. In other words, thebottom surface 35 a andside surfaces 35 b of theretaining chamber 35 are defined by parts of thefirst housing member 21. Thebottom surface 35 a in theretainer 36 is curved along thecylindrical wall 23. The retainingchamber 35 further has atop surface 35 c, which is the inner surface of thecover 38. In the retainingchamber 35, the distance between thebottom surface 35 a and thetop surface 35 c decreases at the middle section of the retainingchamber 35 and increases at the peripheral sections on each side (left and right sides as viewed in FIG. 3) of the retainingchamber 35. - An
inverter 41, which drives theelectric motor 25, is retained in theretainer 36. Theinverter 41 supplies thestator 25 a of theelectric motor 25 with power in accordance with a command from an air conditioner ECU (not shown). - As shown in FIGS.3 to 5, the
inverter 41 includes afirst circuit board 42 and asecond circuit board 43, which are for use in a power system, and athird circuit board 44, which is for use in a control system. A switchingdevice assembly 70, acapacitor 46, and electric components of the power system that configure an inverter circuit (not shown), such as a transformer, are connected to thefirst circuit board 42. The switchingdevice assembly 70 includes a plurality of switching devices 45 (six in the preferred embodiment). - A plurality of electrolysis capacitors47 (five in the preferred embodiment), which are electric components of the power system configuring the inverter circuit, are mounted on the
plane 43 a of thesecond circuit board 43. Theelectrolysis capacitors 47 are cylindrical and configure a smoothening circuit. The smoothening circuit stabilizes the battery voltage applied to a power system circuit of theinverter 41. Theelectrolysis capacitors 47 occupy much space in the retainingchamber 35. Thus, thesecond circuit board 43 is separated from thefirst circuit board 42 to efficiently use the limited space in the retainingchamber 35 of theretainer 36. Adriver 48 mounted on thethird circuit board 44 intermittently controls theswitching devices 45 in accordance with commands from, for example, the air conditioner ECU. - As shown in FIG. 3, relatively large electric components, such as the switching
device assembly 70 and thecapacitor 46 are connected to thelower surface 42 a of thefirst circuit board 42. Thelower surface 42 a of thefirst circuit board 42 faces towards thebottom surface 35 a of the retainingchamber 35. Thethird circuit board 44 is arranged between thefirst circuit board 42 and thecover 38 in theretainer 36. Thefirst circuit board 42 and thethird circuit board 44 are arranged in theretainer 36 in a superimposed manner. Thefirst circuit board 42 is fixed to thecompressor housing 11 by bolts (not shown). Thethird circuit board 44 is fixed to thefirst circuit board 42 by bolts (not shown). - Resin molding, such as insert molding, is performed to integrate the six
switching devices 45 into theswitching device assembly 70. Resin molding is performed by arranging theswitching devices 45 in two rows and filling connectingresin 57 into the space between the switchingdevices 45 so as to connect theswitching devices 45. - The six
switching devices 45 of theswitching device assembly 70 each include abody 45 a and threeterminals 45 b extending from one end of thebody 45 a. Among the threeterminals 45 b, two are bent. The remainingterminal 45 b extends straight from the end of thebody 45 a. Due to such configuration, the wiring pattern (not shown) of thecircuit board 42, to which the distal portions of theterminals 45 b are connected, is not dense. - The six
switching devices 45 are arranged in two rows in the longitudinal direction of theswitching device assembly 70. Thebent terminals 45 b of theswitching devices 45 in each row are aligned in the longitudinal direction. Thestraight terminal 45 b is arranged between thebent terminals 45 b in each switchingdevice 45. - As shown in FIG. 3, the switching
device assembly 70 is the component that projects the most from thefirst circuit board 42. If a component projecting from thefirst circuit board 42 is arranged in the central portion of theretainer 36 where the distance between thebottom surface 35 a and thetop surface 35 c of the retainingchamber 35 is small, the distance between thelower surface 42 a of thefirst circuit board 42 and the outer surface of thecylindrical wall 23 must be increased. This enlarges theretainer 36, which in turn, enlarges theelectric compressor 10 in the radial direction (i.e., the direction perpendicular to the axis L). - However, in the preferred embodiment, the switching
device assembly 70 is connected to thefirst circuit board 42 at the peripheral section (left side as viewed in FIG. 3) where the distance between thebottom surface 35 a and thetop surface 35 c of the retainingchamber 35 is large. Such arrangement of theswitching device assembly 70 enables thefirst circuit board 42 to be positioned near thecylindrical wall 23. As a result, the size of theretainer 36 may be reduced, and theelectric compressor 10 may be made more compact. - The arrangement of the
switching device assembly 70, which is a projecting component, in one side of the retainingchamber 35 provides a relatively large space from the middle portion of the retainingchamber 35 to the other side (right side as viewed in FIG. 3) of the retainingchamber 35 between thefirst circuit board 42 and thebottom surface 35 a of the retainingchamber 35. In this space, theelectrolysis capacitors 47, which occupy much space, are arranged in a row in the circumferential direction of thecylindrical wall 23. Accordingly, the layout of theswitching device assembly 70 in one side of theretainer 36 not only enables the size of theelectric compressor 10 to be reduced in the radial direction but also enables efficient usage of the space in theretainer 36. - As shown in FIGS. 3 and 5, the
plane 43 a of thesecond circuit board 43 is perpendicular to the axis L of thecompressor housing 11. As a result, the axes of theparallel electrolysis capacitors 47 are parallel to the axis L of thecompressor housing 11. - The
second circuit board 43 has a flat surface and a bent portion at the middle in correspondence with thebottom surface 35 a of the retainingchamber 35. The fiveelectrolysis capacitors 47 are connected to thesecond circuit board 43 in a manner forming a line that is bent at the middle so as to follow the curve of thebottom surface 35 a. - A
resin capacitor holder 49 fixes the fiveelectrolysis capacitors 47 to thecompressor housing 11. Thecapacitor holder 49 has five holdingportions 49 a to hold the fiveelectrolysis capacitors 47. Thecapacitor holder 49 is formed so that the line defined by the holdingportions 49 a is bent at the middle in accordance with the bent line of theelectrolysis capacitors 47. - When the
electrolysis capacitors 47 are held in the holdingportions 49 a, thecapacitor holder 49 is fastened to thecompressor housing 11 by bolts 60 (refer to FIG. 5). This holds theelectrolysis capacitors 47 between thecapacitor holder 49 and thebottom surface 35 a of the retainingchamber 35. - A
resin sheet 50 is arranged on thebottom surface 35 a of the retainingchamber 35 to separate thebottom surface 35 a from thecapacitor 46 and theelectrolysis capacitors 47. Thesheet 50 may be made of rubber as long as it has superior elastic and heat conducting properties. That is, thecapacitor 46 and theelectrolysis capacitors 47 indirectly contact thebottom surface 35 a of the retainingchamber 35 by means of thesheet 50. - As shown in FIGS. 3 and 4, a
groove 51 is formed in theouter surface 23 b of thecylindrical wall 23 of thecompressor housing 11 in the retainingchamber 35. More specifically, afirst wall 52 and asecond wall 53, which are parallel to the axis L, define thegroove 51. Theside wall 37 of theretainer 36 that is located near the switchingdevice 45 serves as thefirst wall 52. Thesecond wall 53 is extended from theouter surface 23 b of thecylindrical wall 23 in theretainer 36. A part of theouter surface 23 b of the cylindrical wall 23 (bottom surface 35 a of the retaining chamber 35) functions as abottom surface 51 a of thegroove 51, which connects thefirst wall 52 and thesecond wall 53. - As shown in FIG. 4, an
inner surface 52 a of thefirst wall 52 faces towards aninner surface 53 a of thesecond wall 53 in thegroove 51. Theinner surfaces second walls rotary shaft 27 as viewed in FIG. 3. - The
switching devices 45 each have aheat radiating surface 45 c, which is faced to the associatedinner surface groove 51. In other words, the switchingdevice assembly 70 has sixheat radiating surfaces 45 c, three on each side of the switching device assembly 70 (FIG. 4). - The
heat radiating surface 45 c is the surface of thebody 45 a from which a conducting portion of a transistor, which forms the switchingdevice 45, is exposed. The conducting portion is encircled in eachheat radiating surface 45 c in FIG. 4. - When the
switching device assembly 70 is received in thegroove 51, theheat radiating surface 45 c of each switchingdevice 45 contacts the correspondinginner surface groove 51. More specifically, in the row of the threeswitching devices 45 that are closer to thefirst wall 52, theheat radiating surfaces 45 c contact theinner surface 52 a of thefirst wall 52. Further, in the row of the threeswitching devices 45 that are closer to thesecond wall 53, theheat radiating surfaces 45 c contact theinner surface 53 a of thesecond wall 53. - An
elastic sheet 54 is arranged between theheat radiating surfaces 45 c of theswitching devices 45 and theinner surfaces groove 51. Theelastic sheet 54 is made of rubber or resin. Further, thesheet 54 has a superior heat conducting property. - When the
switching device assembly 70 is received in thegroove 51, aflat fastening plate 55 is fixed to thecompressor housing 11 to cover the opening of thegroove 51. Thefastening plate 55 functions as a fastening member and a pressure applying body. - The lower surface of the fastening plate55 (as viewed in FIG. 3) presses the
switching device assembly 70 in a direction parallel to the vertical line S. As described above, theheat radiating surfaces 45 c of theswitching device 45 and theinner surfaces groove 51 are inclined relative to the vertical line S. Accordingly, when thefastening plate 55 presses theswitching device assembly 70 in the direction parallel to the vertical line S, theheat radiating surfaces 45 c of theswitching devices 45 are pressed strongly against theinner surfaces groove 51 through thesheet 54. In the preferred embodiment, thefastening plate 55 functions to press theswitching devices 45 against theinner surfaces groove 51. - As shown in FIG. 4, a plurality of insertion holes55 a are extend through the
fastening plate 55. Theterminals 45 b of theswitching devices 45 are inserted through the corresponding insertion holes 55 a. Then, thefastening plate 55 is fastened to thecompressor housing 11 bybolts 58. After thefirst circuit board 42 is fixed to thecompressor housing 11, theterminals 45 b projecting out of the insertion holes 55 a of thefastening plate 55 are soldered. - Referring to FIGS.1 to 3, a
refrigerant gas passage 33 connecting thesuction port 31 to thecompression mechanism 26 passes by thegroove 51 in thecompressor housing 11. More specifically, therefrigerant gas passage 33 is defined between theinner surface 23 a of thecylindrical wall 23 and the outer surface of thestator 25 a of theelectric motor 25 at a location corresponding to thegroove 51. Therefrigerant gas passage 33 extends parallel to the axis L of therotary shaft 27. - The low temperature refrigerant gas directed toward the
compression mechanism 26 from thesuction port 31 flows through therefrigerant gas passage 33 to cool theswitching devices 45. Heat exchange between the switchingdevices 45 and the coolercylindrical wall 23 is performed mainly at locations where theheat radiating surfaces 45 c of theswitching devices 45 contact the correspondinginner surfaces groove 51. - The preferred embodiment has the advantages described below.
- (1) The
groove 51 is formed in theouter surface 23 b of thecompressor housing 11. In other words, thebottom surface 51 a andinner surfaces groove 51 are provided by thecompressor housing 11, the temperature of which is low. Accordingly, thecompressor housing 11 cools theswitching devices 45 more easily in comparison to, for example, when theswitching devices 45 are arranged outside thegroove 51. This improves the heat exchange efficiency between the switchingdevice 45 and thecompressor housing 11 in comparison to the heat exchange described in, for example, Japanese Laid-Open Utility Model Publication No. 62-12471. Further, this cools theinverter 41 in a preferable manner, improves the durability of theinverter 41, and stabilizes the operation of theinverter 41. - (2) The
fastening plate 55 connected to thecompressor housing 11 presses theswitching device assembly 70 against theinner surfaces groove 51. As a result, theheat radiating surfaces 45 c of theswitching devices 45 come into close contact with the correspondinginner surfaces groove 51. This improves the heat exchange efficiency between the switchingdevices 45 and thecompressor housing 11. - (3) In comparison to when providing a
groove 51 for each switchingdevice 45, the accommodation of theswitching devices 45 in thesingle groove 51 reduces the machining cost of thecompressor housing 11. - (4) The
switching device assembly 70, which is formed from the unit of theswitching devices 45, is inserted in thegroove 51. Accordingly, theswitching devices 45 are inserted in thegroove 51 at the same time by inserting theswitching device assembly 70. This simplifies assembly of theelectric compressor 10. - (5) The
inner surfaces groove 51 are inclined relative to the vertical line S of thegroove 51 so that the distance between theinner surfaces groove 51 decreases as thebottom surface 51 a of thegroove 51 becomes closer. Accordingly, theheat radiating surfaces 45 c of theswitching devices 45 come into close contact with the correspondinginner surfaces groove 51 as if a wedge is inserted into thecompressor housing 11. This further improves heat exchange efficiency between the switchingdevice 45 and thecompressor housing 11. - (6) The
elastic sheet 54 is arranged between theheat radiating surfaces 45 c of theswitching devices 45 and the correspondinginner surfaces groove 51. Accordingly, elastic deformation of thesheet 54 absorbs dimensional differences and increases contact between theheat radiating surfaces 45 c of theswitching devices 45 and the correspondinginner surfaces groove 51. Further, the superior heat conductance of thesheet 54 further improves the heat exchange efficiency between the switchingdevices 45 and thecompressor housing 11. Theelastic sheet 54 also protects theswitching devices 45 from impacts, or the like, applied to thecompressor housing 11. - (7) In the
compressor housing 11, therefrigerant gas passage 33, which connects the low pressure side of the external refrigeration circuit 61 (the side in which theevaporator 64 is located) to thecompression mechanism 26, passes by thegroove 51. Accordingly, the low temperature refrigerant gas that passes by thegroove 51 effectively cools theswitching devices 45. - (8) The
inverter 41 is retained in the retainingchamber 35 of thecompressor housing 11. Thebottom surface 35 a and side surface 35 b of the retainingchamber 35 are part of thecompressor housing 11. This reduces the number of components in comparison to when preparing a retainer separately from the compressor housing 11 (e.g., when retaining theinverter 41 in a case and attaching the case to the compressor housing 11). Further, theinverter 41 is surrounded by thecompressor housing 11, which has high rigidity. This is effective for protecting the inverter from external impacts. - (9) The
elastic sheet 50 separates theelectrolysis capacitors 47 and thecapacitor 46 from thebottom surface 35 a of the retainingchamber 35. Accordingly, elastic deformation of thesheet 50 absorbs dimensional differences and increases contact of theelectrolysis capacitors 47 and thecapacitor 46 against thebottom surface 35 a of the retainingchamber 35. Further, the superior heat conductance of thesheet 50 further improves the heat exchange efficiency of thecapacitors compressor housing 11. Theelastic sheet 50 also protects thecapacitors compressor housing 11. - (10) The
switching device assembly 70 is connected to thefirst circuit board 42 after arranging theswitching device assembly 70 in thegroove 51. Accordingly, by adjusting the insertion of theterminals 45 b of theswitching devices 45 for thefirst circuit board 42, dimensional differences of each portion is absorbed and theheat radiating surfaces 45 c of theswitching devices 45 come into close contact with the correspondinginner surfaces groove 51. This further improves heat exchange efficiency between the switchingdevices 45 and thecompressor housing 11. - (11) The axes M of the
electrolysis capacitors 47 are parallel to each other and to the axis L of the rotary shaft 27 (cylindrical wall 23). For example, in comparison to when the axes M of theelectrolysis capacitors 47 are arranged in a direction perpendicular to the axis L of thecylindrical wall 23 or when theelectrolysis capacitors 47 are not arranged in the same direction, the projecting height of the inverter 41 (retainer 36) from thecylindrical wall 23 is decreased. Thus, theelectric compressor 10 does not have to be enlarged in the radial direction. - (12) The
electrolysis capacitors 47 are arranged in a row along theouter surface 23 b of thecylindrical wall 23. Accordingly, in comparison to, for example, when arranging theelectrolysis capacitors 47 in a stacked manner, the projecting height of the inverter 41 (retainer 36) from thecylindrical wall 23 is decreased. - (13) The
electrolysis capacitors 47 are held between thecapacitor holder 49 and thecylindrical wall 23. In other words, thecapacitor holder 49 fixes theelectrolysis capacitors 47 to thecompressor housing 11. In comparison to, for example, when indirectly fixing theelectrolysis capacitors 47 to thecompressor housing 11 with thesecond circuit board 43, the fastening of theelectrolysis capacitors 47 to thecompressor housing 11 is guaranteed. This improves vibration resistance of theelectrolysis capacitors 47. Thus, theelectric compressor 10 of the preferred embodiment is especially desirable under harsh vibration conditions, such as in an automobile. - (14) The
electrolysis capacitors 47 are connected to thesecond circuit board 43, which is separated from thefirst circuit board 42. By separating thesecond circuit board 43 from thefirst circuit board 42, freedom of layout for thesecond circuit board 43 increases in thecompressor housing 11. In other words, freedom of layout for theelectrolysis capacitors 47 increases. - (15) The
electrolysis capacitors 47 are arranged between thefirst circuit board 42 and thecylindrical wall 23. Due to the difference in the shapes of thefirst circuit board 42, which is flat, and thecylindrical wall 23, which is curved, it is difficult to arrange electric components in the space between thefirst circuit board 42 and thecylindrical wall 23. However, in the preferred embodiment, theelectrolysis capacitors 47 are arranged in the space in an orderly manner along theouter surface 23 b of thecylindrical wall 23. The layout of theelectrolysis capacitors 47 in the space between thefirst circuit board 42 and thecylindrical wall 23, which would otherwise be dead space, is extremely effective for decreasing the height that theinverter 41 projects from thecylindrical wall 23. - It should be apparent to those skilled in the art that the present invention may be embodied in many other specific forms without departing from the spirit or scope of the invention. Particularly, it should be understood that the present invention may be embodied in the following forms.
- As shown in FIG. 6, the
groove 51 may be formed so that its opposinginner surfaces heat radiating surfaces 45 c of theswitching devices 45 in theswitching device assembly 71 are parallel to the vertical line S. - As shown in FIG. 7, a
third wall 59 may be arranged between thefirst wall 52 and thesecond wall 53. In this case, thecompressor housing 11 has twogrooves 51. Three of theswitching devices 45 are arranged in each of thegrooves 51. A switchingdevice assembly 72, which is formed by integrating threeswitching devices 45A into aswitching device assembly 72 with resin, is inserted in eachgroove 51. - In the embodiments of FIGS.1 to 7, the
sheet 54 arranged between theheat radiating surfaces 45 c of theswitching devices 45 and theinner surfaces groove 51 may be eliminated. Further, theheat radiating surfaces 45 c of theswitching devices 45 may come into direct contact with the correspondinginner surfaces groove 51. - Instead of bending the row of the
electrolysis capacitors 47 at the middle, the row of theelectrolysis capacitors 47 may be linear. - The
electrolysis capacitors 47 may be stacked upon one another. - In the embodiments of FIGS.1 to 7, the
capacitor holder 49 may be eliminated, and thesecond circuit board 43 may be fixed to thecompressor housing 11 or theother circuit boards electrolysis capacitors 47 may be indirectly connected to thecompressor housing 11 through thesecond circuit board 43. This would decrease the number of components. - In the embodiments of FIGS.1 to 7, the
second circuit board 43 may be eliminated and wires may be connected directly to theelectrolysis capacitors 47. In this case, by integrating theelectrolysis capacitors 47 with resin beforehand, theelectrolysis capacitors 47 may easily be attached to thecompressor housing 11. - In the embodiments of FIGS.1 to 7, in addition to the
plane 43 a of thesecond circuit board 43, theelectrolysis capacitors 47 may be arranged on the plane on the other side of thesecond circuit board 43. - The present invention may be applied to an electric compressor in which the electric motor is separated from the compression mechanism. In this case, the inverter is arranged in the compressor housing, which accommodates the compression mechanism.
- The present invention may be applied to an electric compressor in which the electric motor and compression mechanisms are arranged in different compressor housings. In this case, the inverter may be arranged in the compressor housing accommodating the electric motor or in the compressor housing accommodating the compression mechanism.
- The present invention may be embodied in a so-called hybrid compressor, which uses an automotive drive source, or an engine, as another compressor drive source.
- The
compression mechanism 26 does not have to be a scroll type mechanism and may be a piston type, vane type, or helical type mechanism. - The present examples and embodiments are to be considered as illustrative and not restrictive, and the invention is not to be limited to the details given herein, but may be modified within the scope and equivalence of the appended claims.
Claims (21)
1. An electric compressor for use in a refrigeration circuit, the electric compressor comprising:
a housing having an outer surface;
an electric motor;
a compression mechanism accommodated in the housing, wherein the compression mechanism is driven by the electric motor to compress a refrigerant;
an inverter attached to the outer surface of the housing to drive the electric motor and including a switching device having a heat radiating surface;
a groove formed in the outer surface of the housing and having a wall, wherein the switching device is inserted in the groove so that the heat radiating surface contacts the wall of the groove.
2. The electric compressor according to claim 1 , further comprising:
a pressure applying body for pressing the switching device toward the wall of the groove.
3. The electric compressor according to claim 1 , wherein the switching device is one of a plurality of switching devices, the heat radiating surface of each of the switching devices contacts the wall of the groove.
4. The electric compressor according to claim 3 , wherein the plurality of switching devices are integrated into a switching device assembly beforehand.
5. The electric compressor according to claim 1 , wherein the wall of the groove includes two opposed wall surfaces, wherein one of the wall surfaces inclines at a predetermined angle relative to the other one of the wall surfaces so that the distance between the two wall surfaces decreases at deeper positions in the groove.
6. The electric compressor according to claim 5 , further comprising:
a fastening member for fastening the switching device to the housing, wherein the fastening member presses the switching device into the groove, and the heat radiating surface is pressed against the two inner surfaces.
7. The electric compressor according to claim 5 , wherein the switching device is one of a plurality of switching devices, the plurality of switching devices are integrated into a switching device assembly arranged in a substantially wedge-like manner beforehand.
8. The electric compressor according to claim 7 , wherein the switching device assembly has two outer surfaces, each facing one of the two wall surfaces of the groove, the outer surface faces the two outer surfaces inclined relative to each other at an angle that is the same as said predetermined angle, and the heat radiating surface of each of the switching devices is exposed from one of the two outer surfaces.
9. The electric compressor according to claim 8 , wherein the plurality of switching devices includes at least one switching device exposed from one of the two outer surfaces of the switching device assembly and at least one other switching device exposed from the other one of the two outer surfaces.
10. The electric compressor according to claim 1 , further comprising:
an elastic sheet arranged between the heat radiating surface of the switching device and the wall of the groove.
11. The electric compressor according to claim 1 , wherein the refrigeration circuit includes the electric compressor and an external circuit connected to the electric compressor, and the housing includes a refrigerant gas passage for drawing refrigerant gas into the compression mechanism from the external circuit, and the refrigerant gas passage passes by the groove.
12. The electric compressor according to claim 1 , wherein the inverter includes a circuit board to which the switching device is connected, the switching devices being connected to the circuit board after inserting the switching device into the groove.
13. The electric compressor according to claim 1 , wherein part of the housing defines a retainer for retaining the inverter.
14. An electric compressor comprising:
a housing having a cylindrical wall with an outer surface and an axis;
an electric motor;
a compression mechanism accommodated in the housing for being driven by the electric motor; and
an inverter attached to the outer surface of the cylindrical wall to drive the electric motor, and including a plurality of cylindrical electrolysis capacitors, each electrolysis capacitor having an axis, the axes of the electrolysis capacitors being parallel to one another and parallel to the axis of the cylindrical wall.
15. The electric compressor according to claim 14 , wherein the electrolysis capacitors are arranged in a line along a circumferential direction of the cylindrical wall.
16. The electric compressor according to claim 14 , further comprising:
a capacitor holder attached to the housing, wherein the electrolysis capacitors are held between the capacitor holder and the cylindrical wall.
17. The electric compressor according to claim 14 , wherein the inverter further includes:
a switching device;
a first circuit board; and
a second circuit board separated from the first circuit board, wherein the switching device is mounted on the first circuit board, and the electrolysis capacitors are mounted on the second circuit board.
18. The electric compressor according to claim 17 , wherein the second circuit board is curved in correspondence with the outer surface of the cylindrical wall.
19. The electric compressor according to claim 14 , wherein the inverter further includes:
a switching device; and
a circuit board on which the switching device is mounted, wherein the electrolysis capacitors are arranged between the circuit board and the cylindrical wall.
20. The electric compressor according to claim 14 , further comprising:
an elastic sheet arranged between the electrolysis capacitors and the cylindrical wall, wherein each of the electrolysis capacitors is pressed against the outer surface of the cylindrical wall by the sheet.
21. An electric compressor for use in a refrigeration circuit, the electric compressor comprising:
a housing having a cylindrical wall with an outer surface and an axis;
an electric motor;
a compression mechanism accommodated in the housing, and when operated, the compression mechanism being driven by the electric motor;
an inverter attached to the outer surface of the cylindrical wall to drive the electric motor, and including a switching device having a heat radiating surface and a plurality of cylindrical electrolysis capacitors, each electrolysis capacitor having an axis, the axes of the electrolysis capacitors being parallel to one another and parallel to the axis of the cylindrical wall
a groove having a wall is formed in the outer surface of the housing, and the switching device is inserted in the groove so that the heat radiating surface contacts the wall of the groove.
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
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JP2002206004A JP2004044554A (en) | 2002-07-15 | 2002-07-15 | Electric compressor |
JP2002-206004 | 2002-07-15 | ||
JP2002-206005 | 2002-07-15 | ||
JP2002206005A JP2004044555A (en) | 2002-07-15 | 2002-07-15 | Motor-driven compressor |
Publications (1)
Publication Number | Publication Date |
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US20040052660A1 true US20040052660A1 (en) | 2004-03-18 |
Family
ID=31996080
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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US10/619,041 Abandoned US20040052660A1 (en) | 2002-07-15 | 2003-07-14 | Electric compressor |
Country Status (2)
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US (1) | US20040052660A1 (en) |
DE (1) | DE10331877A1 (en) |
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US20050063836A1 (en) * | 2003-02-19 | 2005-03-24 | Kazuya Kimura | Electric compressor and method of assembling the same |
EP1657439A1 (en) * | 2004-11-11 | 2006-05-17 | Matsushita Electrical Industrial Co., Ltd | Sealed type electric compressor |
US20070231165A1 (en) * | 2006-03-29 | 2007-10-04 | Tatsuya Koide | Electric compressor |
US20100247349A1 (en) * | 2007-12-13 | 2010-09-30 | Mitsubishi Heavy Industries, Ltd. | Integrated-inverter electric compressor |
EP2287467A1 (en) * | 2008-05-14 | 2011-02-23 | Mitsubishi Heavy Industries, Ltd. | Inverter-integrated electrically-powered compressor |
US20120275939A1 (en) * | 2010-02-16 | 2012-11-01 | Heng Sheng Precision Tech. Co., Ltd. | Electrically Driven Compressor System for Vehicles |
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US20210025466A1 (en) * | 2018-03-30 | 2021-01-28 | Haldex Vie (Shanghai) Electromechanical Brake System Co., Ltd. | Motor Control Module, Actuator and Electromechanical Brake Apparatus |
DE112014004826B4 (en) | 2013-10-22 | 2024-04-18 | Sanden Corporation | Electric compressor |
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US20050063836A1 (en) * | 2003-02-19 | 2005-03-24 | Kazuya Kimura | Electric compressor and method of assembling the same |
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US10371147B2 (en) * | 2006-01-25 | 2019-08-06 | Kabushiki Kaisha Toyota Jidoshokki | Electrically-driven compressor |
US20180066659A1 (en) * | 2006-01-25 | 2018-03-08 | Kabushiki Kaisha Toyota Jidoshokki | Electrically-driven compressor |
US20070231165A1 (en) * | 2006-03-29 | 2007-10-04 | Tatsuya Koide | Electric compressor |
US7972123B2 (en) | 2006-03-29 | 2011-07-05 | Kabushiki Kaisha Toyota Jidoshokki | Electric compressor |
US20100247349A1 (en) * | 2007-12-13 | 2010-09-30 | Mitsubishi Heavy Industries, Ltd. | Integrated-inverter electric compressor |
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US10125775B2 (en) | 2013-06-25 | 2018-11-13 | Kabushiki Kaisha Toyota Jidoshokki | Motor-driven compressor |
EP2818717A1 (en) * | 2013-06-25 | 2014-12-31 | Kabushiki Kaisha Toyota Jidoshokki | Motor-driven compressor |
US20140377095A1 (en) * | 2013-06-25 | 2014-12-25 | Kabushiki Kaisha Toyota Jidoshokki | Motor-driven compressor |
CN104251188A (en) * | 2013-06-25 | 2014-12-31 | 株式会社丰田自动织机 | Motor-driven compressor |
CN104421134A (en) * | 2013-08-23 | 2015-03-18 | 株式会社丰田自动织机 | Electric compressor |
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DE112014004826B4 (en) | 2013-10-22 | 2024-04-18 | Sanden Corporation | Electric compressor |
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CN108291540A (en) * | 2016-11-07 | 2018-07-17 | 翰昂汽车零部件有限公司 | Motor compressor with electrical connection mechanism and the stator assembly for it |
US20210025466A1 (en) * | 2018-03-30 | 2021-01-28 | Haldex Vie (Shanghai) Electromechanical Brake System Co., Ltd. | Motor Control Module, Actuator and Electromechanical Brake Apparatus |
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