Patent Application
20180355869
This application claims foreign priority benefits under U.S.C. ยง 119 to French Patent Application No. 17/55316 filed on Jun. 13, 2017, the content of which is hereby incorporated by reference in its entirety.
The present invention relates to a scroll compressor, and in particular to a hermetic scroll compressor.
U.S. Pat. No. 6,474,964 discloses a scroll compressor including:
Therefore, the second flow undergoes a certain pressure drop due to the flow through narrow passages through the driving motor, and the first flow also undergoes a certain pressure drop due to the configuration of the fluid deflecting and dividing device.
Hereby, the total pressure losses in the first and second flows are high, and the overall efficiency of the scroll compressor is thus low.
It is an object of the present invention to provide an improved scroll compressor which can overcome the drawbacks encountered in conventional scroll compressors.
Another object of the present invention is to provide a scroll compressor which has an improve efficiency while allowing to control the motor cooling.
According to the invention such a scroll compressor includes:
Such a configuration of the fluid deflecting and dividing device allows to directly guide the first flow towards the compression unit, and thus to substantially increase the efficiency of the scroll compressor.
Moreover, the fluid deflecting and dividing device according to the present invention induces lower frictional losses and less turbulences, and thus substantially reduces the pressure losses, which is especially important in scroll compressors using low density refrigerants (such as R134a) and high volume flow rate.
Further such a configuration of the fluid deflecting and dividing device ensures a control of the motor cooling depending on the positioning of the fluid deflecting and dividing device with respect to the refrigerant suction inlet and the driving motor.
Furthermore such a configuration of the fluid deflecting and dividing device ensures to control the percentage of refrigerant which is guided directly towards the compression unit and the percentage of refrigerant which is guided towards the driving motor depending on the height of the first end of the fluid deflecting and dividing device relatively to the refrigerant suction inlet.
In addition, such a configuration of the fluid deflecting and dividing device allows controlling the oil circulation rate, since a part of the refrigerant suction flow entering the scroll compressor is directly guided towards the scroll compressor.
The scroll compressor may also include one or more of the following features, taken alone or in combination.
According to an embodiment of the invention, the fluid deflecting and dividing device is configured such that the first flow is directly guided towards the compression unit.
According to an embodiment of the invention, the scroll compressor is a hermetic scroll compressor.
According to an embodiment of the invention, the refrigerant suction inlet emerges radially in an inner volume defined by the outer shell.
According to an embodiment of the invention, the first end and the second end are offset with respect to each other in an axial direction of the drive shaft, and are advantageously vertically offset with respect to each other.
According to an embodiment of the invention, the fluid deflecting and dividing device is stationary relative to the outer shell.
According to an embodiment of the invention, the fluid deflecting and dividing device includes an intermediate portion located between the first and second ends, the intermediate portion including a bottom plate and a plurality of blades protruding from the bottom plate. The presence of said blades improves the guiding and the spread of the first flow towards the compression unit, ensures a better repartition of the refrigerant inside the outer shell, and thus further improves the efficiency of the scroll compressor.
According to an embodiment of the invention, the blades of the plurality of blades diverge from each other towards the second end of the fluid deflecting and dividing device. Such a configuration of the blades ensures a circumferential guiding of the refrigerant inside the inner volume delimited by the outer shell, and ensures homogeneous velocities of the refrigerant through refrigerant apertures provided in the support frame which partially bears the compression unit.
According to an embodiment of the invention, each of the plurality of blades extends substantially up to the second end of the fluid deflecting and dividing device.
According to an embodiment of the invention, the plurality of blades include a plurality of main blades and a plurality of intermediate blades, each intermediate blade extending between two adjacent main blades and having a length smaller than a length of each the two adjacent main blades. Such a configuration of the blades ensures a homogenous repartition of the refrigerant inside the inner volume delimited by the outer shell, and thus limits the pressure drop in refrigerant apertures provided in the support frame.
According to an embodiment of the invention, each intermediate blade has an inwardly curved leading edge.
According to an embodiment of the invention, each main blade extends substantially from the first end of the fluid deflecting and dividing device, and each intermediate blade is offset from the first end of the fluid deflecting and dividing device.
According to an embodiment of the invention, the plurality of main blades includes two outer main blades and several inner main blades located between the two outer main blades, each of the two outer main blades having a height higher than a height of each of the inner main blades.
According to an embodiment of the invention, each of the two outer main blades protrudes from the first end of the fluid deflecting and dividing device and towards the refrigerant suction inlet.
According to an embodiment of the invention, the two outer main blades define two lateral edges of the fluid deflecting and dividing device.
According to an embodiment of the invention, the plurality of blades delimits diverging and upwardly extending flow channels.
According to an embodiment of the invention, each of the plurality of blades has a substantially constant thickness.
According to an embodiment of the invention, the bottom plate includes a curved guiding portion extending substantially from the first end of the fluid deflecting and dividing device, the curved guiding portion being configured to guide the first flow towards the second end of the fluid deflecting and dividing device. Such a configuration of the bottom plate ensures a smooth guiding of the first flow towards the compression unit
According to an embodiment of the invention, the scroll compressor further includes an inner shell surrounding the driving motor, the fluid deflecting and dividing device being secured to an outer surface of the inner shell. As the fluid deflecting and dividing device is not secured to the outer shell (which is the case for conventional scroll compressors) but to the inner shell, the distance between the refrigerant suction inlet and the fluid deflecting and dividing device is bigger. Thus securing the fluid deflecting and dividing device to the inner shell allows setting a high turning radius, which is lowering the pressure loss and lets some space to ensure a proper azimuthal distribution of the refrigerant.
According to an embodiment of the invention, the driving motor is entirely mounted inside the inner shell.
According to an embodiment of the invention, the bottom plate further includes a mounting portion having a shape substantially complementary to the outer surface of the inner shell.
According to an embodiment of the invention, the second end of the fluid deflecting and dividing device has a shape substantially complementary to the outer surface of the inner shell.
According to an embodiment of the invention, the inner shell is provided with a refrigerant inlet aperture facing the refrigerant suction inlet.
According to an embodiment of the invention, the refrigerant inlet aperture is partially covered by the fluid deflecting and dividing device. In other words, the fluid deflecting and dividing device is partially overlying the refrigerant inlet aperture.
In other words, the fluid deflecting and dividing device extends at least partially between the refrigerant inlet aperture and the refrigerant suction inlet.
According to an embodiment of the invention, the refrigerant inlet aperture is partially covered by the curved guiding portion of the fluid deflecting and dividing device.
According to an embodiment of the invention, the inner shell and the driving motor define a proximal chamber containing a first winding head of a stator, and a distal chamber containing a second winding head of the stator, the first winding head being closer to the compression unit than the second winding head and the second winding head being opposite to the first winding head.
According to an embodiment of the invention, the first winding head is formed by the portions of the stator windings extending outwardly from a first end face of a stator core, and the second winding head is formed by the portions of the stator windings extending outwardly from a second end face of the stator core opposite to the first end face.
According to an embodiment of the invention, the refrigerant inlet aperture emerges in the distal chamber.
According to an embodiment of the invention, the refrigerant inlet aperture is configured to fluidly connect the distal chamber and an annular volume delimited by the inner shell and the outer shell, the refrigerant suction inlet emerging in the annular volume.
According to an embodiment of the invention, the second end of the deflecting and dividing device extends over at least 120 degrees, and for example on approximately 180 degree, of the circumference of the inner shell.
According to an embodiment of the invention, the second end of the fluid deflecting and dividing device is curved, and advantageously extends along a circular arc, for example over at least 120 degrees, and preferably over about 180 degrees.
According to an embodiment of the invention, the second end of the fluid deflecting and dividing device has a radius of curvature substantially equal to a radius of curvature of the outer surface of the inner shell.
According to an embodiment of the invention, the scroll compressor further includes a support frame which bears at least partially the compression unit and which includes at least one refrigerant aperture, the fluid deflecting and dividing device being configured to guide the first flow towards the compression unit via the at least one refrigerant aperture provided on the support frame.
According to an embodiment of the invention, the fluid deflecting and dividing device is manufactured by 3D-printing.
According to an embodiment of the invention, the material used for 3D-printing the fluid deflecting and dividing device is chosen among ABS (Acrylonitrile Butadiene Styrene), PET (Polyethylene Terephthalate), PLA (Polylactic Acid), SLS Nylon, or any other suitable material for 3D printing (plastic or metallic).
According to an embodiment of the invention, the first end of the fluid deflecting and dividing device is substantially located at a same height than a central portion of the refrigerant suction inlet, and for example at a same height than a central axis of the refrigerant suction inlet.
According to an embodiment of the invention, the support frame includes several refrigerant apertures which are circumferentially distributed.
According to an embodiment of the invention, the compression unit includes a fixed scroll having a fixed base plate and a fixed spiral wrap, and an orbiting scroll having an orbiting base plate and an orbiting spiral wrap, the fixed spiral wrap and the orbiting spiral wrap forming a plurality of compression chambers.
According to an embodiment of the invention, the support frame includes a thrust bearing surface on which is slidably mounted the orbiting scroll.
According to an embodiment of the invention, the support frame includes an upper radial bearing for guiding the drive shaft.
According to an embodiment of the invention, the drive shaft includes a driving portion configured to drive the orbiting scroll in an orbital movement.
According to an embodiment of the invention, an upper end of the inner shell is secured to the support frame.
According to an embodiment of the invention, a lower end of the inner shell is secured to a centering member secured to the outer shell, the centering member being provided with a guide bearing configured to guide a lower end portion of the drive shaft.
According to an embodiment of the invention, a flow section of the refrigerant suction inlet includes a first flow section portion facing the fluid deflecting and dividing device, and a second flow section portion which is offset in the axial direction of the drive shaft, and for example vertically offset, from the fluid deflecting and dividing device. The second flow section portion may for example face the refrigerant inlet aperture.
In other words, the scroll compressor is configured so that an orthogonal projection of the fluid deflecting and dividing device on a reference plane which extends perpendicularly to a central axis of the refrigerant suction inlet is partially covering an orthogonal projection of the refrigerant suction inlet on said reference plane.
According to an embodiment of the invention, the first flow section portion represents from 20% to 80% of the flow section of the refrigerant suction inlet.
According to an embodiment of the invention, the first flow section portion faces the curved guiding portion of the fluid deflecting and dividing device.
According to an embodiment of the invention, the curved guiding portion of the fluid deflecting and dividing device has a scoop shape.
These and other advantages will become apparent upon reading the following description in view of the drawings attached hereto representing, as non-limiting example, one embodiment of a scroll compressor according to the invention.
The following detailed description of one embodiment of the invention is better understood when read in conjunction with the appended drawings being understood, however, that the invention is not limited to the specific embodiment disclosed.
The hermetic scroll compressor 2 further comprises a refrigerant suction inlet 7 provided on the outer shell 4 and configured to supply the hermetic scroll compressor 2 with refrigerant to be compressed, and a discharge outlet 8 configured to discharge compressed refrigerant. For example, the discharge outlet 8 may be provided on the upper cap 5.
The hermetic scroll compressor 2 also comprises a support frame 9 arranged within the hermetic enclosure 3 and secured to the hermetic enclosure 3, and a compression unit 11 also arranged within the hermetic enclosure 3 and disposed above the support frame 9. The compression unit 11 is configured to compress the refrigerant supplied by the refrigerant suction inlet 7, and includes a fixed scroll 12, which is fixed in relation to the hermetic enclosure 3, and an orbiting scroll 13 supported by and in slidable contact with a thrust bearing surface 10 provided on the support frame 9.
The fixed scroll 12 includes a fixed scroll base plate 14 having a lower face oriented towards the orbiting scroll 13, and an upper face opposite to the lower face of the fixed scroll base plate 14. The fixed scroll 12 also includes a fixed spiral wrap 15 protruding from the lower face of the fixed scroll base plate 14 towards the orbiting scroll 13.
The orbiting scroll 13 includes an orbiting scroll base plate 16 having an upper face oriented towards the fixed scroll 12, and a lower face opposite to the upper face of the orbiting scroll base plate 16 and slidably mounted on the thrust bearing surface 10. The orbiting scroll 13 also includes an orbiting spiral wrap 17 protruding from the upper face of the orbiting base plate 16 towards the fixed scroll 12. The orbiting spiral wrap 17 meshes with the fixed spiral wrap 15 to form a plurality of compression chambers 18 between them. Each of the compression chambers 18 has a variable volume which decreases from the outside towards the inside, when the orbiting scroll 13 is driven to orbit relative to the fixed scroll 12.
Furthermore the hermetic scroll compressor 2 includes a drive shaft 19 configured to drive the orbiting scroll 13 in an orbital movement, and a driving motor 21, which may be a variable-speed driving motor, coupled to the drive shaft 19 and configured to drive in rotation the drive shaft 19 about a rotational axis A.
The driving motor 21 has a rotor 22 fitted on the drive shaft 19, and a stator 23 disposed around the rotor 22. The stator 23 includes a stator stack or stator core 24, and stator windings wound on the stator core 24. The stator windings define a first winding head 25.1 which is formed by the portions of the stator windings extending outwardly from a first end face 24.1 of the stator core 24 which is oriented towards the compression unit 11, and a second winding head 25.2 which is formed by the portions of the stator windings extending outwardly from a second end face 24.2 of the stator core 24 which is opposite to the compression unit 11.
The hermetic scroll compressor 2 further includes an inner shell 26 surrounding the driving motor 21 and in which the driving motor 21 is entirely mounted.
As shown in
The inner shell 26 is further provided with a refrigerant inlet aperture 29 facing the refrigerant suction inlet 7 and emerging in the distal chamber 28. The refrigerant inlet aperture 29 is configured to fluidly connect the distal chamber 28 and an annular volume 31 delimited by the inner shell 26 and the outer shell 4.
According to the embodiment shown on the figures, an upper end of the inner shell 26 is secured to the support frame 9, and a lower end of the inner shell 26 is secured to a centering member 32 secured to the outer shell 4.
The hermetic scroll compressor 2 further includes an upper bearing member 33 provided on the support frame 9 and configured to cooperate with an outer circumferential wall surface of an upper end portion of the drive shaft 19, and a lower bearing member 34 provided on the centering member 32 and configured to cooperate with an outer circumferential wall surface of a lower end portion of the drive shaft 19. The lower bearing member 34 and the upper bearing member 33 are particularly configured to rotatably support the drive shaft 19.
The hermetic scroll compressor 2 also includes a fluid deflecting and dividing device 35 secured to an outer surface of the inner shell 26. Advantageously, the fluid deflecting and dividing device 35 extends at least partially between the refrigerant inlet aperture 29 and the refrigerant suction inlet 7.
The hermetic scroll compressor 2 is configured so that an orthogonal projection of the fluid deflecting and dividing device 35 on a reference plane which extends perpendicularly to a central axis B of the refrigerant suction inlet 7 is partially covering an orthogonal projection of the refrigerant suction inlet 7 on said reference plane. In other words, the flow section of the refrigerant suction inlet 7 includes a first flow section portion 7.1, i.e. an upper flow section portion, facing the fluid deflecting and dividing device 35, and a second flow section portion, i.e. a lower flow section portion, which is vertically offset from the fluid deflecting and dividing device 35 and which particularly faces a lower portion of the refrigerant inlet aperture 29. For example, the first flow section portion 7.1 represents from 20% to 80%, advantageously about 50%, of the flow section of the refrigerant suction inlet 7.
The fluid deflecting and dividing device 35 is thus configured to divide a refrigerant suction flow, entering the hermetic scroll compressor 2 through the refrigerant suction inlet 7, into a first flow F1 and a second flow F2, and is further configured to guide the first flow F1 directly towards the compression unit 11, via several refrigerant apertures 36 which are provided on the support frame 9 and which are circumferentially distributed, and to guide the second flow F2 towards the refrigerant inlet aperture 29 in order to cool at least parts of the driving motor 21.
As better shown on
According to the embodiment shown on the figures, the first end 37 of the fluid deflecting and dividing device 35 is substantially located at a same height than a central portion of the refrigerant suction inlet 7, and advantageously substantially at a same height than the central axis B of the refrigerant suction inlet 7.
According to the embodiment shown on the figures, the second end 38 of the fluid deflecting and dividing device 35 is curved, and has a radius of curvature substantially equal to a radius of curvature of the outer surface of the inner shell 26. Advantageously, the second end 38 of the fluid deflecting and dividing device 35 extends over at least 120 degrees, and for example on approximately 180 degree, of the circumference of the inner shell 26.
The fluid deflecting and dividing device 35 further includes an intermediate portion 39 located between the first and second ends 37, 38. The intermediate portion 39 includes a bottom plate 41 comprising a curved guiding portion 41.1 extending from the first end 37 of the fluid deflecting and dividing device 35, and a mounting portion 41.2 extending from the curved guiding portion 41.1 and up to the second end 38. Advantageously, the mounting portion 41.2 has a shape substantially complementary to the outer surface of the inner shell 26.
According to an embodiment of the invention, the curved guiding portion 41.1 partially covers the refrigerant inlet aperture 29, and is particularly configured to guide the first flow F1 towards the second end 38 of the fluid deflecting and dividing device 35. The curved guiding portion 41.1 of the fluid deflecting and dividing device 35 may have for example a scoop shape. Advantageously, the first flow section portion 7.1 of the refrigerant suction inlet 7 faces the curved guiding portion 41.1.
The intermediate portion 39 also includes a plurality of blades 42 respectively formed by wall portions protruding from the bottom plate 41, and extending along the curved guiding portion 41.1 and the mounting portion 41.2.
Advantageously, the blades 42 diverge from each other towards the second end 38 of the fluid deflecting and dividing device 35, and delimit diverging and upwardly extending flow channels 43. Particularly, the blades 42 include a plurality of main blades 44 and a plurality of intermediate blades 45, each intermediate blade 45 extending between two adjacent main blades 44 and having a length smaller than a length of each the two adjacent main blades 44.
According to the embodiment shown on the figures, each main blade 44 extends from the first end 37 of the fluid deflecting and dividing device 35 and up to the second end 38 of the fluid deflecting and dividing device 35, and each intermediate blade 45 is offset from the first end 37 of the fluid deflecting and dividing device 35 and extends up to the second end 38 of the fluid deflecting and dividing device 38. Advantageously, each intermediate blade 45 has an inwardly curved leading edge.
Such a configuration of the various blades 42 ensures a circumferential guiding of the refrigerant, from the first flow F1, inside the annular volume 31, and a homogenous repartition of said refrigerant inside the annular volume 31, and thus ensures homogeneous velocities of the refrigerant through the refrigerant apertures 36 provided on the support frame 9.
According to the embodiment shown on the figures, the main blades 44 includes two outer main blades 44.1 defining two lateral edges of the fluid deflecting and dividing device 35, and several inner main blades 44.2 located between the two outer main blades 44.1. Advantageously, each of the two outer main blades 44.1 has a height higher than a height of each of the inner main blades 44.2, and protrudes from the first end 37 of the fluid deflecting and dividing device 35 and towards the refrigerant suction inlet 7.
The fluid deflecting and dividing device 35 may be manufactured by 3D-printing, and the material used for 3D-printing the fluid deflecting and dividing device is chosen among ABS (Acrylonitrile Butadiene Styrene), PET (Polyethylene Terephthalate), PLA (Polylactic Acid), SLS Nylon, or any other suitable material for 3D printing (plastic or metallic).
Of course, the invention is not restricted to the embodiment described above by way of non-limiting example, but on the contrary it encompasses all embodiments thereof.
While the present disclosure has been illustrated and described with respect to a particular embodiment thereof, it should be appreciated by those of ordinary skill in the art that various modifications to this disclosure may be made without departing from the spirit and scope of the present disclosure.
| Number | Date | Country | Kind |
|---|---|---|---|
| 1755316 | Jun 2017 | FR | national |
