Scroll compressor provided with a stator winding baffle

Abstract

The scroll compressor (2) comprises a hermetic enclosure (3) comprising an outer shell (4); a compression unit (11) arranged within the hermetic enclosure (3); an electric motor (21) configured to drive the compression unit (11), the electric motor (21) including a rotor (22) and a stator (23); and an inner shell (26) in which the electric motor (21) is arranged. A baffle (34) is arranged inside the inner shell (26) at a stator end winding (25) of the electric motor (21), the baffle (34) comprising deflecting means configured to deflect at least a part of a main refrigerant flow, flowing inside the inner shell (26), towards said stator end winding (25).

Claims

1. A scroll compressor comprising: a hermetic enclosure comprising an outer shell, a compression unit arranged within the hermetic enclosure, an electric motor configured to drive the compression unit with a drive shaft, the electric motor including a rotor and a stator, and an inner shell arranged within the hermetic enclosure and in which the electric motor is arranged, wherein a baffle is arranged inside the inner shell at a stator end winding of the electric motor, the baffle comprising deflecting means configured to deflect at least a part of a main refrigerant flow, flowing inside the inner shell, towards said stator end winding; wherein the baffle defines a refrigerant outlet opening; wherein the drive shaft is arranged in the refrigerant outlet opening wherein the baffle has a circular ring shape; wherein the baffle includes a first axial section having an outer diameter substantially corresponding to an inner diameter of the inner shell, and a second axial section having an outer diameter smaller than the outer diameter of the first axial section and having an inner diameter larger than an outer diameter of said stator end winding; and wherein the baffle further comprises a radially extending end wall which extends from the second axial section, the radially extending end wall defining the refrigerant outlet opening.

2. The scroll compressor according to claim 1, wherein the first axial section includes at least one circumferential guiding portion having an inner guiding surface, the deflecting means and the inner guiding surface of the at least one circumferential guiding portion are configured to force a refrigerant flow entering the baffle in contact to said stator end winding.

3. The scroll compressor according to claim 2, wherein a lower axial end surface of the at least one circumferential guiding portion rests on an upper surface of a stator core.

4. The scroll compressor according to claim 3, wherein the first axial section includes at least one arcuate portion adjacent the at least one circumferential guiding portion, the at least one arcuate portion having a radius of curvature substantially corresponding to a radius of curvature of an inner surface of the inner shell.

5. The scroll compressor according to claim 2, wherein the first axial section includes at least one arcuate portion adjacent the at least one circumferential guiding portion, the at least one arcuate portion having a radius of curvature substantially corresponding to a radius of curvature of an inner surface of the inner shell.

6. The scroll compressor according to claim 5, wherein a lower axial end of the at least one circumferential guiding portion protruding in an axial direction from a lower axial end of the at least one arcuate portion.

7. The scroll compressor according to claim 2, wherein the first axial section includes a plurality of circumferential guiding portions which are angularly offset and circumferentially distributed, and a plurality of arcuate portions which are angularly offset and circumferentially distributed, each of the arcuate portions extending between two adjacent circumferential guiding portions.

8. The scroll compressor according to claim 1, wherein a circular gap (G) is defined between the rotor and the stator, and at least one outer flow channel (C) is formed between an outer surface of the stator and an inner surface of the inner shell, the scroll compressor being configured such that a first refrigerant flow part of the main refrigerant flow flows through the at least one outer flow channel (C) and a second refrigerant flow part of the main refrigerant flow flows through the circular gap (G).

9. The scroll compressor according to claim 8, wherein the baffle and the stator define at least one refrigerant inlet opening through which the first refrigerant flow part can enter the baffle.

10. The scroll compressor according to claim 8, wherein the first axial section is configured to collect the first refrigerant flow part of the main refrigerant flow and to deflect the first refrigerant flow part in both radial and circumferential directions along a surface of said stator end winding.

11. The scroll compressor according to claim 8, wherein the baffle is angularly oriented in relation to the stator such that the at least one outer flow channel (C) is axially aligned with the at least one arcuate portion of the baffle.

12. The scroll compressor according to claim 1, wherein the deflecting means includes a plurality of deflecting elements formed on an inner surface of the baffle.

13. The scroll compressor according to claim 12, wherein each of the deflecting elements protrudes from a transition portion between the first and second axial sections.

14. The scroll compressor according to claim 12, wherein each of the deflecting elements includes a curved blade shaped wall.

15. The scroll compressor according to claim 12, wherein each of the deflecting elements is configured to deflect a part of the main refrigerant flow towards a respective circumferential guiding portion.

16. The scroll compressor according to claim 1, wherein the baffle is arranged at an upper stator end winding of the electric motor, and wherein the deflecting means are configured to deflect at least a part of the main refrigerant flow, flowing inside the inner shell from a lower end of the electric motor towards an upper end of the electric motor, towards the upper stator end winding.

17. The scroll compressor according to claim 16, wherein the baffle covers the upper stator end winding.

18. A scroll compressor comprising: a hermetic enclosure comprising an outer shell, a compression unit arranged within the hermetic enclosure, an electric motor configured to drive the compression unit with a drive shaft, the electric motor including a rotor and a stator, and an inner shell arranged within the hermetic enclosure and in which the electric motor is arranged, wherein a baffle is arranged inside the inner shell at a stator end winding of the electric motor, the baffle comprising deflecting means configured to deflect at least a part of a main refrigerant flow, flowing inside the inner shell, towards said stator end winding; wherein the baffle defines a refrigerant outlet opening; wherein the drive shaft is arranged in the refrigerant outlet opening; wherein the baffle has a circular ring shape; wherein the baffle includes a first axial section having an outer diameter substantially corresponding to an inner diameter of the inner shell, and a second axial section having an outer diameter smaller than the outer diameter of the first axial section and having an inner diameter larger than an outer diameter of said stator end winding; wherein the first axial section includes at least one circumferential guiding portion having an inner guiding surface, the deflecting means and the inner guiding surface of the at least one circumferential guiding portion are configured to force a refrigerant flow entering the baffle in contact to said stator end winding; wherein the first axial section includes at least one arcuate portion adjacent the at least one circumferential guiding portion, the at least one arcuate portion having a radius of curvature substantially corresponding to a radius of curvature of an inner surface of the inner shell; and wherein a lower axial end of the at least one circumferential guiding portion protruding in an axial direction from a lower axial end of the at least one arcuate portion.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) 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.

(2) FIG. 1 is a longitudinal section view, in perspective, of a scroll compressor according to the invention.

(3) FIG. 2 is a partial longitudinal section view of the scroll compressor of FIG. 1.

(4) FIG. 3 is a perspective view from above of a baffle of the scroll compressor of FIG. 1.

(5) FIG. 4 is a perspective view from below of the baffle of FIG. 3.

(6) FIG. 5 is a cross section view of the scroll compressor of FIG. 1.

(7) FIG. 6 is another cross section view of the scroll compressor of FIG. 1.

DETAILED DESCRIPTION

(8) FIG. 1 shows a scroll compressor 2 comprising a hermetic enclosure 3 including an outer shell 4, an upper cap 5 and a baseplate 6. As shown on FIG. 1, the outer shell 4 is cylindrical and includes an upper end closed by the upper cap 5 and a lower end closed by the baseplate 6. According to the embodiment shown on the figures, the outer shell 4 has a constant diameter over its entire length.

(9) The scroll compressor 2 further comprises a refrigerant suction inlet (not shown on the figures) provided on the outer shell 4 and configured to supply the 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.

(10) The 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, 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.

(11) 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.

(12) 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 between them. Each of the compression chambers 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.

(13) Furthermore the scroll compressor 2 includes a drive shaft 19 configured to drive the orbiting scroll 13 in an orbital movement, and an electric motor 21, which may be a variable-speed electric motor, coupled to the drive shaft 19 and configured to drive in rotation the drive shaft 19 about a rotational axis A.

(14) The electric 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 two stator end windings 25, and particularly an upper stator end winding 25.1 which is formed by the portions of the stator windings extending outwardly from an upper end face of the stator core 24 which is oriented towards the compression unit 11, and a lower stator end winding 25.2 which is formed by the portions of the stator windings extending outwardly from a lower end face of the stator core 24 which is opposite to the compression unit 11.

(15) The scroll compressor 2 further includes an inner shell 26 surrounding the electric motor 21 and in which the electric motor 21 is entirely mounted. 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 27 secured to the outer shell 4. As shown in FIG. 1, the inner shell 26 and the electric motor 21 define a proximal chamber 28 containing the upper stator end winding 25.1 of the stator 23, and a distal chamber 29 containing the lower stator end winding 25.2 of the stator 23. The stator 23 may be secured to the inner shell 26, e.g. by press fitting, shrink fitting, welding, screwing or other suitable methods.

(16) Furthermore the scroll compressor 2 includes one or several refrigerant inlet aperture(s) (not shown in the drawings) emerging in the distal chamber 29. Each refrigerant inlet aperture is particularly configured to fluidly connect the distal chamber 29 and an annular volume 31 delimited by the inner shell 26 and the outer shell 4, such that a main refrigerant flow, entering the distal chamber 29 through the refrigerant inlet aperture(s), may flow inside the inner shell 26 from a lower end of the electric motor 21 towards an upper end of the electric motor 31. According to an embodiment of the invention, the or each refrigerant inlet aperture may be provided on a lower end portion of the inner shell 26.

(17) According to the embodiment shown on the figures, a circular gap G is defined between the rotor 22 and the stator 23, and a plurality of outer flow channels C are formed between the outer surface of the stator 23 and the inner surface of the inner shell 26. Advantageously, the outer flow channels C are angularly offset and circumferentially distributed. Each outer flow channel C may particularly be defined by the inner surface of the inner shell 26 and a respective flat peripheral portion of the outer surface of the stator core 24.

(18) Particularly, the scroll compressor 2 is configured such that a first refrigerant flow part of the main refrigerant flow flows through the outer flow channels C and a second refrigerant flow part of the main refrigerant flow flows through the circular gap G.

(19) The scroll compressor 2 further includes an upper bearing member 32 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 33 provided on the centering member 27 and configured to cooperate with an outer circumferential wall surface of a lower end portion of the drive shaft 19. The lower bearing member 33 and the upper bearing member 32 are particularly configured to rotatably support the drive shaft 19.

(20) The scroll compressor 2 also includes a baffle 34 having a circular ring shape and being arranged inside the inner shell 26 at the upper stator end winding 25.1. The baffle 34 is particularly arranged inside the proximal chamber 28 so as to cover the upper stator end winding 25.1. The baffle 34 may be produced in metallic or plastic materials, preferably in glass-fiber reinforced plastic materials, e.g. PA66. Alternatively, the baffle 34 may be manufactured with additive manufacturing processes.

(21) The baffle 34 includes a first axial section 35 having an outer diameter substantially corresponding to an inner diameter of the inner shell 26, and a second axial section 36 having an outer diameter smaller than the outer diameter of the first axial section 35 and having an inner diameter larger than an outer diameter of the upper stator end winding 25.1. Advantageously, each of the first and second axial sections 35, 36 has a substantially circular ring shape.

(22) As better shown on FIGS. 4 and 5, the first axial section 35 includes a plurality of circumferential guiding portions 37 which are angularly offset and circumferentially distributed, and a plurality of arcuate portions 38 which are angularly offset and circumferentially distributed. Each arcuate portion 38 is a circular arcuate portion and has a radius of curvature substantially corresponding to a radius of curvature of the inner surface of the inner shell 26, and particularly extends between two adjacent circumferential guiding portions 37. Advantageously, the baffle 34 is angularly oriented in relation to the stator 23 such that each outer flow channel C is axially aligned with a respective arcuate portion 38 of the baffle 34.

(23) Each circumferential guiding portion 37 has an outer surface 37.1 which is located away from the inner surface of the inner shell 26. Advantageously, the outer surface 37.1 of each circumferential guiding portion 37 is recessed, i.e. defines a recess. Further each circumferential guiding portion 37 has an inner guiding surface 37.2 which defines a bump portion.

(24) According to the embodiment shown on the figures, each circumferential guiding portion 37 is curved and extends inwardly. Particularly the outer surface 37.1 of each circumferential guiding portion 37 is concave and the inner guiding surface 37.2 of each circumferential guiding portion 37 is convex.

(25) Further each circumferential guiding portion 37 includes a lower axial end 37.3 protruding in an axial direction from the lower axial ends 38.1 of the arcuate portions 38, and a lower axial end surface 37.4 which rests on an upper surface of the stator core 24.

(26) Moreover the baffle 34 and the stator 23 define a plurality of refrigerant inlet openings 39 which are angularly offset and circumferentially distributed, and through which the first refrigerant flow part of the main refrigerant flow can enter the baffle 34. Advantageously, each refrigerant inlet opening 39 is defined by the stator core 24 and the lower axial end 38.1 of a respective arcuate portion 38.

(27) According to the embodiment shown on the figures, the inner surface of the second axial section 36 and the outer surface of the upper stator end winding 25.1 define a flow channel 41 for the first refrigerant flow part of the main refrigerant flow. Advantageously, the width of the flow channel 41 is configured to ensure a good heat transfer between refrigerant and the upper stator end winding 25.1 without excessive pressure losses.

(28) The baffle 34 further comprise a radially extending end wall 42 which extends from the second axial section 36. The radially extending end wall 42 is located above the upper stator end winding 25.1 and defines a refrigerant outlet opening 43 which has a circular shape. Advantageously, the refrigerant outlet opening 43 has an inner diameter smaller than the inner diameter of the stator 23.

(29) The scroll compressor 2 is particularly configured such that the second refrigerant flow part of the main refrigerant flow, coming from the circular gap G, flows along the radial inner surface of the upper end stator winding 25.1, through the refrigerant outlet opening 43 and then along the outer surface of the support frame 9. Advantageously, the refrigerant outlet opening 43 is dimensioned such that the second refrigerant flow part flows through the refrigerant outlet opening 43 substantially unrestricted. Thus the second refrigerant flow part is less affected by the baffle 34 than the first refrigerant flow part.

(30) The baffle 34 further includes deflecting means configured to deflect at least a part of the first refrigerant flow part towards the upper stator end winding 25.1. The deflecting means include a plurality of deflecting elements 44 formed on the inner surface of the baffle 34. According to the embodiment shown on the figures, each deflecting element 44 protrudes from the inner surface of a transition portion 45 located between the first and second axial sections 35, 36, and is partially located at an arcuate portion 38. Advantageously, two deflecting elements 44 are formed at each arcuate portion 38.

(31) Further each deflecting element 44 defines a deflecting recess 46 which is downwardly open and which is laterally open. Advantageously each deflecting element 44 includes a curved blade shaped wall and a lateral free edge 47 which is away from the inner surface of the first axial section 35.

(32) Each deflecting element 44 is particularly configured to deflect a part of the first refrigerant flow part towards a respective circumferential guiding portion 37. Therefore the first axial section 35 is configured to collect the first refrigerant flow part of the main refrigerant flow and to deflect the first refrigerant flow part in both radial and circumferential directions along the outer surface of the upper stator end winding 25.1. Furthermore the deflecting elements 44 and the guiding inner surfaces 37.1 of the circumferential guiding portions 37 are configured to force a part of the first refrigerant flow part entering the baffle 34 in close contact to the upper stator end winding 25.1.

(33) As better shown on FIGS. 3 and 5, the baffle 34 further includes mounting bosses 48 which are circumferentially distributed. Each mounting boss 48 protrudes from the outer surface of the second axial section 36 and extends radially outwardly. Particularly radial end surfaces of the mounting bosses 48 cooperate with the inner surface of the inner shell 26.

(34) The mounting bosses 48 may be used to secure the baffle 34 to the inner shell 26, e.g. by screws. Preferably, each mounting boss 48 comprises a threaded insert 49, and for example a metallic threaded insert, to accommodate a suitable fixing element. Alternatively, the baffle 34 may be secured to the inner shell 26 by further known methods, such as adhesive, clips and rivets, or by press fit.

(35) 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. Particularly, the baffle 34 could be used in a scroll compressor 2 where the electric motor 21 is arranged in a high pressure volume, instead of the low pressure (suction pressure) volume as shown in the drawings.