Spiral compressor featuring an intermediate shell with a barrel-shaped section

Abstract

The scroll compressor (2) comprises a compressor housing (3) having an upper shell (6), an intermediate shell (7), and a lower shell (8); a compression unit (11) mounted inside the compressor housing (3); a drive shaft (14) disposed inside the compressor housing (3) in the intermediate shell (7) and configured to drive the drive shaft (14) in rotation; an oil sump (9) disposed inside the compressor housing (3) in the lower shell (8); and a base (16) attached to the lower shell (8). The intermediate shell (7) has at least one barrel-shaped section (B) extending in an axial direction (Z), the at least one barrel-shaped section (B) having a longitudinal profile that is arched and has a radius of curvature. Figure 1

Description

Title of the invention: Spiral compressor having an intermediate shell with a barrel-shaped section Field of invention

[0001] The invention relates to a scroll compressor. Prior art

[0002] Scroll compressors are widely used for refrigeration applications. However, the scope of applications is limited, particularly due to a high noise level produced during the operation of a scroll compressor. The sound level of a scroll compressor is generally between 80 dB(A) and 90 dB(A) and above, which is a major issue for applications near human activities.

[0003] A scroll compressor typically comprises a compressor casing comprising a lower shell delimiting an oil sump, an intermediate shell provided with a suction volume and housing an electric motor, and an upper shell provided with a compression volume and a discharge volume.

[0004] The main sources of noise in a scroll compressor are the compression of the refrigerant at the compression volume, the mechanical contact between the fixed scroll and the orbiting scroll and the discharge of a compressed refrigerant into the discharge volume. There are also noise sources which are less significant compared to the sources in the upper shell. For example, such a noise source may be the electric motor.

[0005] In recent years, many efforts have been made to reduce the overall noise level of a scroll compressor.

[0006] One way to ensure noise reduction of a scroll compressor is to provide a noise-reducing cover that completely covers the scroll compressor. An example of such solutions is disclosed in US2005274569A1. However, such solutions reduce the noise generated by a scroll compressor passively. In other words, a scroll compressor still generates noise (and thus, for example, vibrations, which affect the life of a compressor), but the noise felt by a user is reduced. Furthermore, such solutions affect the cooling of a scroll compressor and thus a scroll compressor is exposed to overheating.

[0007] Another type of technical solution to ensure noise reduction of a scroll compressor is to include additional silencer devices inside the scroll compressor in the upper shell. As an example of a such solution, FR3129693A1 discloses a discharge silencer which is located in the discharge volume and mounted at a discharge passage leading from the compression volume. However, such solutions may affect the flow of refrigerant through the scroll compressor and may thus affect the efficiency of a scroll compressor.

[0008] For reciprocating compressors, which are not included in the present invention, it is known from the prior art to design an outer casing of a hermetic compressor that is capable of reducing noise and vibration. Examples of solutions are disclosed in US4384635A and US5281105A. However, these solutions developed for reciprocating compressors cannot be easily introduced into scroll compressors, which have, for example, different internal arrangements of the electric motor and the compression assembly, a different type of movement of the compression assembly, a different structure of the compressor casing and a different arrangement of the suction volume and the discharge volume. Furthermore, the known solutions from reciprocating compressors aim at reducing the overall noise of an entire reciprocating compressor and not just a specific part of the reciprocating compressor.It should be noted that some parts of a scroll compressor have limited design freedom due to their function, for example the lower shell with the oil sump. The lower shell should also be adapted to ensure secure support with a scroll compressor base.

[0009] As a result, the prior art does not provide solutions for reducing the noise of a scroll compressor coming from an intermediate shell. Furthermore, since an intermediate shell is generally manufactured by rolling and welding a tube, design freedom is limited.

[0010] The present invention aims to overcome the aforementioned drawbacks of the prior art solutions and to provide a scroll compressor with improved noise reduction. In particular, the present invention aims to provide a scroll compressor with an intermediate shell improved in terms of noise reduction properties for noise coming from the intermediate shell of the scroll compressor. Summary of the invention

[0011] According to the present invention, there is provided a scroll compressor comprising:

[0012] - a compressor casing provided with a suction connection configured to supply the scroll compressor in refrigerant gas to be compressed and a discharge connection configured to discharge the compressed refrigerant gas, wherein the compressor casing comprises an upper shell, an intermediate shell and a lower shell,

[0013] - a compression unit mounted inside the compressor housing and configured to compress the refrigerant gas supplied through the suction connection, wherein the compression unit comprises a fixed scroll and an orbiting scroll configured to perform orbiting motion relative to the fixed scroll during operation of the scroll compressor,

[0014] - a drive shaft disposed inside the compressor housing and coupled to the orbiting scroll,

[0015] - an electric motor arranged inside the compressor housing in the shell intermediate and configured to drive the drive shaft in rotation,

[0016] - an oil sump disposed inside the compressor housing and delimited at least partially through the lower hull, and

[0017] - a base fixed to the lower hull,

[0018] characterized in that the intermediate shell comprises at least one section in the shape barrel extending in an axial direction, the at least one barrel-shaped section having a longitudinal profile which is arched and which has a radius of curvature.

[0019] Such a configuration of the intermediate shell, and in particular the presence of the at least one barrel-shaped section, reduces major acoustic parameters such as the number of nodal modes, the equivalent radiated power level, the far-field sound power level, the radiated factor and the harmonic response. Consequently, the noise level generated by the scroll compressor according to the present invention is significantly reduced.

[0020] Furthermore, thanks to the at least one barrel-shaped section, the rigidity of the intermediate shell is improved, which also improves the acoustic properties of the scroll compressor according to the present invention.

[0021] By reducing the acoustic response of the scroll compressor according to the present invention, overall vibrations of the scroll compressor are also reduced. Thus, a risk of crack formation for all pipes connected to the compressor casing is reduced. In addition, a service life of the scroll compressor can be increased.

[0022] Advantageously, with the scroll compressor with an intermediate shell according to the present invention, it is possible to obtain an increase in first modal frequencies in comparison with a standard cylindrical intermediate shell of up to 70% on the first and reduces the overall noise by approximately 3 dB depending on the radius of curvature and the end diameter, also called head diameter, of the barrel-shaped section.

[0023] The scroll compressor may further comprise one or more of the following features, taken separately or in combination.

[0024] According to one embodiment of the invention, the radius of curvature of the at least one barrel-shaped section is substantially constant in the axial direction.

[0025] According to one embodiment of the invention, the radius of curvature of the at least one barrel-shaped section is between 0.5 m and 1.5 m.

[0026] According to one embodiment of the invention, the at least one barrel-shaped section comprises a first end having a first end diameter and a second end having a second end diameter.

[0027] According to one embodiment of the invention, the second end diameter is different from the first end diameter.

[0028] According to one embodiment of the invention, the longitudinal profile of the at least one barrel-shaped section extends from the first end of the at least one barrel-shaped section to the second end of the at least one barrel-shaped section.

[0029] According to one embodiment of the invention, the ratio between the radius of curvature of the at least one barrel-shaped section and the first end diameter is between 1.5 and 4.5.

[0030] According to one embodiment of the invention, the intermediate shell comprises at least one cylindrical end section. Said at least one cylindrical end section facilitates the manufacture of the intermediate shell according to the invention.

[0031] According to one embodiment of the invention, the intermediate shell comprises a first cylindrical end section having a first cylindrical section diameter and a second cylindrical end section having a second cylindrical section diameter, the at least one barrel-shaped section being located axially between the first and second cylindrical end sections.

[0032] According to one embodiment of the invention, at least one of the first cylindrical section diameter and the second cylindrical section diameter is substantially identical to the first end diameter.

[0033] According to one embodiment of the invention, each of the first cylindrical section diameter and the second cylindrical section diameter is substantially identical to the first end diameter.

[0034] According to one embodiment of the invention, the first and second cylindrical end sections have substantially the same length measured in the axial direction.

[0035] According to one embodiment of the invention, the first and second cylindrical sections have different lengths measured in the axial direction.

[0036] According to one embodiment of the invention, the intermediate shell comprises at least a first barrel-shaped section and a second barrel-shaped section each extending in the axial direction, the first barrel-shaped section barrel having a first longitudinal profile which is arched and which has a first radius of curvature and the second barrel-shaped section having a second longitudinal profile which is arched and which has a second radius of curvature.

[0037] According to one embodiment of the invention, the first radius of curvature and the second radius of curvature are different from each other. By providing multiple barrel-shaped sections with different geometries, it is possible to reduce different frequencies of the generated noise.

[0038] According to another embodiment of the invention, the first radius of curvature and the second radius of curvature are substantially identical.

[0039] According to one embodiment of the invention, the first and second barrel-shaped sections have different lengths measured in the axial direction. By providing multiple barrel-shaped sections with different geometries, it is possible to reduce different frequencies of the generated noise.

[0040] According to one embodiment of the invention, a ratio between the length of the first barrel-shaped section and the length of the second barrel-shaped section is between 0.2 and 0.8.

[0041] According to another embodiment of the invention, the first and second barrel-shaped sections have the same length measured in the axial direction.

[0042] According to one embodiment of the invention, the intermediate shell comprises a first cylindrical end section, a second cylindrical end section and first and second barrel-shaped sections located between the first and second cylindrical end sections.

[0043] According to one embodiment of the invention, the intermediate shell has a regular circular cross-section.

[0044] According to one embodiment of the invention, the intermediate shell has a cross-section having at least one lobe. A further corrugation in the form of at least one lobe further increases the rigidity of the intermediate shell and thus further improves the acoustic properties of the scroll compressor according to the present invention.

[0045] According to one embodiment of the invention, the intermediate shell has a cross-section having at least one lobe.

[0046] According to one embodiment of the invention, the intermediate shell has a cross-section having at least two lobes, in which the lobes have the same lobe radii.

[0047] According to one embodiment of the invention, the intermediate shell has a cross-section having at least two lobes, in which the lobes have different lobe radii.

[0048] According to one embodiment of the invention, the intermediate shell has a cross-section having three lobes. The lobes may have different lobe radii or the same lobe radii.

[0049] According to one embodiment of the invention, the intermediate shell has an upper end closed by the upper shell and a lower end closed by the lower shell. Summary description of the drawings

[0050] The following detailed description of several embodiments of the invention will be better understood when read in conjunction with the accompanying drawings, it being understood, however, that the invention is not limited to the specific embodiments disclosed.

[0051] [Fig.l] is a longitudinal sectional view of a scroll compressor according to a first embodiment of the invention.

[0052] [Fig.2] is a partial schematic view in longitudinal section of a hull in intermediate of the scroll compressor of [Fig.l].

[0053] [Fig.3] is a cross-sectional view of the intermediate hull of [Fig.2].

[0054] [Fig.4] is a schematic longitudinal sectional view of an intermediate hull of a scroll compressor according to a second embodiment of the invention.

[0055] [Fig. 5] is a schematic view in longitudinal section of an intermediate shell of a scroll compressor according to a third embodiment of the invention.

[0056] [Fig.6] is a cross-sectional view of an intermediate shell of a scroll compressor according to a fourth embodiment of the invention.

[0057] [Fig.7] is a cross-sectional view of an intermediate hull of a com spiral presser according to a fifth embodiment of the invention.

[0058] Detailed Description of Preferred Embodiments

[0059] Embodiment 1: intermediate hull with a barrel-shaped section

[0060] A first embodiment of a scroll compressor 2 according to the present invention is presented in Figures 1 to 3.

[0061] The scroll compressor 2 comprises a compressor casing 3 provided with a suction connection 4 configured to supply the scroll compressor 2 with refrigerant gas to be compressed and a discharge connection 5 configured to discharge the compressed refrigerant gas.

[0062] The compressor casing 3 comprises an upper shell 6, also called the upper cover, an intermediate shell 7 and a lower shell 8. In particular, the intermediate shell 7 comprises an upper end closed by the upper shell 6 and a lower end closed by the lower shell 8. For example, the suction connection 4 can be provided on the intermediate shell 7 and the discharge connection 5 can be provided on the upper shell 6.

[0063] The scroll compressor 2 also comprises an oil sump 9 arranged inside the compressor casing 3 and delimited by the lower shell 8. The oil sump 9 is configured to store oil.

[0064] Furthermore, the scroll compressor 2 comprises a support frame 10 disposed within the compressor housing 3 and secured to the compressor housing 3, and a compression unit 11 also disposed within the compressor housing 3 and disposed above the support frame 10. The compression unit 11 is configured to compress the refrigerant gas supplied from the suction connection 4, and comprises a fixed scroll 12, which is fixed relative to the compressor housing 3, and an orbiting scroll 13 supported by and in sliding contact with the thrust bearing surface provided on the support frame 10. The orbiting scroll 13 is configured to perform an orbiting movement relative to the fixed scroll 12 during operation of the scroll compressor 2.

[0065] The scroll compressor 2 further comprises a drive shaft 14 arranged inside the compressor casing 3 and configured to drive the orbiting scroll 13 in an orbiting motion, and an electric motor 15 arranged inside the compressor casing 3 and coupled to the drive shaft 14. The electric motor 15 is configured in particular to drive the rotational drive shaft 14 about an axis of rotation A. According to the first embodiment shown in FIGS. 1 to 3, the electric motor 15 is arranged below the support frame 10 and is arranged in an intermediate shell 7.

[0066] In addition, the scroll compressor 2 includes a base 16 attached to the lower shell 8, and configured to provide stable support for the scroll compressor 2. For example, the base 16 may be mounted on two mounting rails extending substantially parallel to each other.

[0067] As best shown in [Fig. 2], the intermediate shell 7 comprises a barrel-shaped section B extending in an axial direction Z. The barrel-shaped section B comprises a first end having a first end diameter DI and a second end having a second end diameter D2 which is identical to the first end diameter DI. The first end diameter DI and the second end diameter D2 are also known as the end diameter or the head diameter of a barrel.

[0068] The barrel-shaped section B has a longitudinal profile which is arched and which has a radius of curvature R. Advantageously, the radius of curvature R of the barrel-shaped section B is constant in the axial direction Z and from the first end of the barrel-shaped section B to the second end of the barrel-shaped section B. The radius of curvature R of the barrel-shaped section B may for example be between 0.5 m and 1.5 m. A ratio between the radius of curvature R of the barrel-shaped section B and the first end diameter DI may be between 1.5 and 4.5.

[0069] According to the first embodiment of the invention, the intermediate shell 7 has a regular circular cross-section, as shown in [Fig. 3], and further comprises a cylindrical end section C secured to the upper shell 6 and an intermediate section E located axially between the barrel-shaped section B and the cylindrical end section C.

[0070] Embodiment 2: intermediate hull with a barrel-shaped section and two cylindrical end sections

[0071] [Fig.4] shows a scroll compressor 2 according to a second embodiment of the present invention which differs from the first embodiment in that the intermediate shell 7 comprises a first cylindrical end section C1 having a first cylindrical section diameter and a second cylindrical end section C2 having a second cylindrical section diameter, and in that the barrel-shaped section B is located axially between the first and second cylindrical end sections C1, C2.

[0072] According to the second embodiment of the invention, each of the first cylindrical section diameter and the second cylindrical section diameter is identical to the first end diameter D1, and thus to the second end diameter D2. However, in other embodiments of the present invention, the first and second cylindrical section diameters may be different from each other, and may be different from the first end diameter D1.

[0073] According to the second embodiment of the invention, the first cylindrical end section C1 and the second cylindrical end section C2 have different lengths measured in the axial direction Z. However, in other embodiments of the present invention, the first cylindrical end section C1 and the second cylindrical end section C2 may have substantially the same length measured in the axial direction Z.

[0074] More embodiment 3: intermediate hull with two barrel-shaped sections and two cylindrical end sections

[0075] [Fig.5] shows a scroll compressor 2 according to a third embodiment of the present invention which differs from the second embodiment essentially in that the intermediate shell 7 comprises a first barrel-shaped section B1 and a second barrel-shaped section B2 located axially between the first and second cylindrical end sections C1, C2 and each extending in the axial direction Z.

[0076] The first barrel-shaped section B1 has a first longitudinal profile which is arched and which has a first radius of curvature RI and the second barrel-shaped section B2 has a second longitudinal profile which is arched and which has a second radius of curvature R2.

[0077] According to the third embodiment of the invention, the first radius of curvature RI and the second radius of curvature R2 are different from each other. However, in other embodiments of the present invention, the first radius of curvature RI may be equal to the second radius of curvature R2.

[0078] According to the third embodiment of the invention, the first and second barrel-shaped sections B1, B2 have different lengths measured in the axial direction Z. A ratio between the length of the first barrel-shaped section B2 may for example be between 0.2 and 0.8. However, in other embodiments of the present invention, the first barrel-shaped section B1 and the second barrel-shaped section B2 may have the same length measured in the axial direction Z.

[0079] In other embodiments of the present invention, the first and second barrel-shaped sections B1, B2 and the first and second cylindrical end sections C1, C2 may be arranged in any order, facing the axial direction Z.

[0080] Embodiment 4: intermediate shell with a circular cross-section with identical lobes

[0081] [Fig. 6] shows a scroll compressor 2 according to a fourth embodiment of the present invention which differs from the first embodiment essentially in that the intermediate shell 7 has a circular cross-section having three identical lobes L, i.e., coils having the same lobe radii. Such an arrangement of identical lobes allows a further increase in the stiffness of the intermediate shell 7 and thus further improves the sound properties of the scroll compressor 2 according to the present invention. In particular, an essentially uniform increase in stiffness can be achieved with identical lobes.

[0082] According to the fourth embodiment of the invention, the lobes L are distributed angularly in a regular manner around the axis of rotation A.

[0083] Embodiment 5: intermediate shell with a circular cross-section with different lobes

[0084] [Fig. 7] shows a scroll compressor 2 according to a fifth embodiment of the present invention which differs from the fourth embodiment essentially in that the intermediate shell 7 has a circular cross-section having three different lobes L1, L2 and L3, i.e. lobes having different lobe radii. Such an arrangement of lobes allows for different stiffness levels at different sections of the intermediate shell 7. By doing so, it is possible to increase the stiffness of the intermediate shell 7 in a particular section / region, for example in an area where additional equipment is mounted on the intermediate hull 7.

[0085] The features described with reference to a particular embodiment of the present invention can, of course, be applied in other embodiments unless otherwise indicated.

[0086] Obviously, the invention is not limited to the embodiments described above as non-limiting examples, but on the contrary embraces all embodiments thereof.

Claims

Claims

1. Scroll compressor (2) comprising: - a compressor casing (3) provided with a suction connection (4) configured to supply the scroll compressor (2) with refrigerant gas to be compressed and a discharge connection (5) configured to discharge the compressed refrigerant gas, wherein the compressor casing (3) comprises an upper shell (6), an intermediate shell (7) and a lower shell (8), - a compression unit (11) mounted inside the compressor casing (3) and configured to compress the refrigerant gas supplied through the suction connection (4), wherein the compression unit (11) comprises a fixed scroll (12) and an orbiting scroll (13) configured to perform an orbiting movement relative to the fixed scroll (12) during operation of the scroll compressor (2), - a drive shaft (14) arranged inside the compressor casing (3) and coupled to the orbiting volute (13),- an electric motor (15) arranged inside the compressor housing (3) in the intermediate shell (7) and configured to drive the drive shaft (14) in rotation, - an oil sump (9) arranged inside the compressor housing (3) and delimited at least partially by the lower shell (8), and - a base (16) fixed to the lower shell (8), characterized in that the intermediate shell (7) comprises at least one barrel-shaped section (B) extending in an axial direction (Z), the at least one barrel-shaped section (B) having a longitudinal profile which is arched and which has a radius of curvature (R).,

2. Scroll compressor (2) according to claim 1, wherein the radius of curvature (R) of the at least one barrel-shaped section (B) is between 0.5 m and 1.5 m.

3. A scroll compressor (2) according to claim 1 or 2, wherein the at least one barrel-shaped section (B) has a first end having a first end diameter (D1) and a second end having a second end diameter (D2).

4. A scroll compressor (2) according to claim 3, wherein the second end diameter (D2) is substantially the same as the first end diameter (D1).

5. A scroll compressor (2) according to claim 3, wherein the second end diameter (D2) is different from the first end diameter (Dl).

6. Scroll compressor (2) according to any one of claims 3 to 5, wherein the ratio between the radius of curvature (R) of the at least one barrel-shaped section (B) and the first end diameter (Dl) is between 1.5 and 4.

5.

7. Scroll compressor (2) according to any one of claims 1 to 6, in which the intermediate shell (7) comprises at least one cylindrical end section (C).

8. A scroll compressor (2) according to any one of claims 1 to 7, wherein the intermediate shell (7) comprises a first cylindrical end section (Cl) having a first cylindrical section diameter and a second cylindrical end section (C2) having a second cylindrical section diameter, the at least one barrel-shaped section (B) being located axially between the first and second cylindrical end sections (Cl, C2).

9. A scroll compressor (2) according to claim 8, wherein at least one of the first cylindrical section diameter and the second cylindrical section diameter is substantially the same as the first end diameter (D1).

10. A scroll compressor (2) according to claim 8 or 9, wherein the first and second cylindrical end sections (C1, C2) have substantially the same length measured in the axial direction (Z).

11. Scroll compressor (2) according to claim 8 or 9, wherein the first and second cylindrical sections (C1, C2) have different lengths measured in the axial direction (Z).

12. A scroll compressor (2) according to any one of claims 1 to 11, wherein the intermediate shell (7) comprises at least a first barrel-shaped section (B1) and a second barrel-shaped section (B2) each extending in the axial direction (Z), the first barrel-shaped section (B1) having a first longitudinal profile which is arcuate and which has a first radius of curvature (RI) and the second barrel-shaped section (B2) having a second longitudinal profile which is arcuate and which has a second radius of curvature (R2).

13. A scroll compressor (2) according to claim 12, wherein the first radius of curvature (RI) and the second radius of curvature (R2) are different from each other.

14. A scroll compressor (2) according to claim 12 or 13, wherein the first and second barrel-shaped sections (B1, B2) have different lengths measured in the axial direction (Z).

15. A scroll compressor (2) according to claim 14, wherein a ratio of the length of the first barrel-shaped section (B1) to the length of the second barrel-shaped section (B2) is between 0.2 and 0.

8.

16. A scroll compressor (2) according to any one of claims 1 to 15, wherein the intermediate shell (7) has a regular circular cross-section.

17. A scroll compressor (2) according to any one of claims 1 to 15, wherein the intermediate shell (7) has a cross-section having at least one lobe.

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