FIELD OF INVENTION

The present invention relates to a scroll compressor.

BACKGROUND OF THE INVENTION

It is known that a scroll compressor includes a first cover fixed on a fixed scroll with a first space inside and a second cover fixed on the first cover with a second space so that a through hole is formed to penetrate the first cover, as disclosed Japanese Unexamined Patent Application Publication No. 2018-53746A hereinafter called PTLL

In PTL1, the compressed refrigerant periodically flows into the first space from the compression mechanism, which causes a discharge pulsation which is a pressure fluctuation in the first space. The discharge pulsation causes vibration in the compressor and can cause noise generated by the compressor. Moreover, noise and vibration may occur due to mechanical moving parts in the compressor.

Furthermore, in case that the rotation speed of the compressor can be changed, there is a possibility that noise and vibration does not reduced.

Therefore, the development of the scroll compressor that can effectively reduce noise and vibration caused by discharge pulsation and the mechanical moving parts with a simple configuration, is required.

CITATION LIST

Patent Literature

PTL 1: Japanese Unexamined Patent Application Publication No. 2018-53746A

SUMMARY OF THE INVENTION

It is an objective of the present inventions to provide a scroll compressor that can effectively reduce noise and vibration caused by discharge pulsation and mechanical moving parts with a simple configuration.

In order to achieve the above objective, an embodiment of the present invention provides a scroll compressor comprising: a first cover fixed on a fixed scroll; and a second cover fixed on the first cover, wherein the first cover includes a first top plate and a first peripheral wall extending downward from the entire circumference of an edge of the first top plate, which is configured to form a first space inside, wherein the second cover includes a second top plate and a second peripheral wall extending downward from the entire circumference of an edge of the second top plate so that an entire lower end of the second peripheral wall connects to the first top plate, which is configured to form a second space inside, wherein the first space connects to a discharge port that penetrates the fixed scroll and allows compressed refrigerant to flow, and wherein multiple through holes are formed to penetrate the first top plate of the first cover so that the through holes with different diameters connect the first space and the second space.

According to the embodiment of the present invention, since the configuration surrounded by the first cover and the second cover includes the second space that communicates only with the first space and multiple through holes that communicate between the first space and the second space, the configuration surrounded by the first cover and the second cover forms a Helmholtz type resonance chamber communicating with the first space.

In the configuration surrounded by the first cover and the second cover, which is the Helmholtz type resonance chamber, the gas inside the second space acts as a spring, and the gas inside the through holes vibrates rigidly to resonate with sounds of specific frequencies. By generating frictional energy between the gas vibrating inside the through holes and inner walls of the through holes, the sound energy caused by discharge pulsation and the vibration energy caused by mechanical moving parts are reduced.

As such, it is possible to reduce noise and vibration caused by discharge pulsation and the mechanical moving parts.

Moreover, since multiple through holes are formed to penetrate the first top plate of the first cover so that the through holes with different diameters connect the first space and the second space, the Helmholtz type resonance chamber that resonates at different specific frequencies with a simple configuration can be formed.

Therefore, the scroll compressor can effectively reduce noise and vibration caused by discharge pulsation and mechanical moving parts with a simple configuration.

BRIEF DESCRIPTION OF DRAWINGS

The principle of the present invention and its advantages will become apparent in the following description taking in consideration with the accompanying drawings in which: FIG.l is an explanation view illustrating a schematic configuration of a scroll compressor 1 including a first cover 40 and a second cover 50 according to an embodiment of the present invention; FIG.2A is a perspective view of the first cover 40 fixed on a fixed scroll 22 and the second cover 50 fixed on the first cover 40 in FIG.l when viewed from obliquely above;

FIG.2B is a perspective view of the first cover 40 and the second cover 50 in FIG.1 when viewed from obliquely below;

FIG.3 is a cross sectional view taken along line III-III of FIG.2A;

FIG.4 is a cross sectional view taken along line IV-IV of FIGG; and

FIGG is a cross sectional view taken along line V-V of FIGG.

DETAILED DESCTIPTION OF EMBODIMENTS OF THE INVENTION

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

FIG.l is an explanation view illustrating a schematic configuration of a scroll compressor 1 according to the embodiment. The scroll compressor 1 is a fluid machine configured to compress and discharge a fluid (i.e., gas refrigerant), and can be a component of a refrigeration cycle apparatus. The scroll compressor 1 according to the embodiment is a vertically-mounted shell compressor.

As shown in FIG.l, the scroll compressor 1 includes a sealed container 10, a suction pipe 12 mounted penetratingly a top face of the sealed container 10 and formed as a hollow cylindrical pipe, a discharge pipe 14 discharging the gas refigerant to the outside, a scroll compression mechanism 20 configured to compress a low-pressure gas refrigerant in a compression chamber 28, and a motor element 30 configured to drive the compression mechanism 20 which are housed in the sealed container 10.

The upper portion of the compression mechanism 20 is supported by a middle shell 10a of the sealed container 10. The compression mechanism 20 is fixed to the middle shell 10a of the sealed container 10 through shrink fit or other method. A sub-frame 16 is provided below the motor element 30. The sub-frame 16 is fixed to the inner circumferential surface of the sealed container 10. An oil sump 18 is formed on a bottom of the sealed container 10. A refrigerating machine oil lubricating sliding parts such as bearings is accumulated in the oil sump 18.

The suction pipe 12 configured to suck a low-pressure gas refrigerant into the compression mechanism 20 from outside is connected to a side surface of the sealed container 10. The discharge pipe 14 configured to discharge a high-pressure gas refrigerant to the outside of the scroll compressor 1 is connected to the side face of the sealed container 10.

The compression mechanism 20 is accommodated in the sealed container 10 and configured to compress the refrigerant sucked from the suction pipe 12 through rotation of a crankshaft 36 that is rotated by the motor element 30. As shown in FIG.l, the compression mechanism 20 includes a fixed scroll 22 and an orbiting scroll 26.

The fixed scroll 22 is fixed to the middle shell 10a at a lower end portion of the fixed scroll 22. As shown in FIG.l, the fixed scroll 22 includes a fixed scroll base plate 22a and a fixed scroll spiral wrap 22b having an involute curve shape so as to form a spiral body and erected on one surface of the fixed scroll base plate 22a. A discharge port 24 configured to discharge a compressed refrigerant is formed in a central part of the fixed scroll 22.

The orbiting scroll 26 is configured to orbit opposed to the fixed scroll 22 without rotating, by a non-illu strated Oldham mechanism. As shown in FIG.l, the orbiting scroll 26 includes an orbiting scroll base plate 26a and an orbiting scroll spiral wrap 26b having an involute curve shape so as to form a spiral body and erected on one surface of the orbiting scroll base plate 26a. An orbiting bearing 26c formed in a bottomed cylindrical shape is formed in a substantially central part on an undersurface of the orbiting scroll base plate 26a. An eccentric shaft portion 36b installed on an upper end of a main shaft portion 36a described later is inserted in the orbiting bearing 26c, in order to cause the orbiting scroll 26 to orbit.

The orbiting scroll spiral wrap 26b is configured to be engaged with the fixed scroll spiral wrap 22b to form the compression chamber 28 between the fixed scroll spiral wrap 22b and the orbiting scroll spiral wrap 26b. The orbiting scroll 26 is configured to orbit opposed to the fixed scroll 22.

As shown in FIG.l, FIG.2A and FIGG, a first cover 40 with a second cover 50 is fixed on the top portion of the fixed scroll 22 by bolts 49.

The first cover 40 includes a first top plate 42, a first peripheral wall 44 extending downward from the entire circumference of an edge of the first top plate 42, and bottom portions 48 for fixing the first cover 40 to the fixed scroll 22. The first cover 40 is formed in a cap shape so as to be in a circular shape when viewed from above.

The first cover 40 is configured to form a first space 46 inside. Namely, the first space 46 is a space surrounded by the first top plate 42, the first peripheral wall 44, and the top portion of the fixed scroll 22. The first space 46 connects to the discharge port 24 that penetrates the fixed scroll 22 and allows compressed refrigerant to flow.

As shown in FIG.2A, FIG.2B and FIGG, the first top plate 42 of the first cover 40 includes multiple extension portions 42a that extends outward beyond the top portion of the fixed scroll 22 when the first cover 40 viewed from above, so as to form gaps 62 between parts of a lower end 44a of the first peripheral wall 44 and the top portion of the fixed scroll 22. Each extension portion 42a is formed to widen in an outward direction. When viewed from above, the bottom portion 48 with an opening 48a through which the bolt 49 penetrates is provided between the two extension portions 42a in order to fix the first cover 40 on the fixed scroll 22 by bolts 49.

As shown in FIG.2B, FIG.3 and FIG.5, the first space 46 includes a plurality of chambers, each of which is surrounded by the extension portion 42a of the first top plate 42, the first peripheral wall 44 extending downward from the extension portion 42a, two bottom portions 48 and the top portion of the fixed scroll 22.

The second cover 50 fixed on the first cover 40 includes a second top plate 52 and a second peripheral wall 54 extending downward from the entire circumference of an edge of the second top plate 52 so that an entire lower end 54a of the second peripheral wall 54 connects to the first top plate 42. The second cover 50 is configured to form a second space 56 inside. As shown in FIG.2A and FIG.4, the second cover 50 is formed in a circle shape when viewed from above and in a bowl shape.

As shown in FIGG and FIG.4, the second space 56 is formed as a chamber which is surrounded by the second top plate 52, the second peripheral wall 54 extending downward from the second top plate 52, and the first cover 40.

As shown in FIG.2B, FIGG FIGG, in the first top plate 42 of the first cover 40, multiple through holes 60a, 60b, 60c, 60d, 60e, 60f, 60g are formed to penetrate the first top plate 42 of the first cover 40 so that the through holes 60a, 60b, 60c, 60d, 60e, 60f, 60g with different diameters connect the first space 46 and the second space 56.

The diameters of the through holes 60a, 60b, 60c, 60d, 60e, 60f, 60g are formed so as to increase in the order of through holes 60a, 60b, 60c, 60d, 60d, 60e, 60f, and 60g. In addition, some of the multiple through holes 60a, 60b, 60c, 60d, 60d, 60e, 60f, and 60g may be formed to be the same diameter.

In the embodiment, the through holea 60a, 60b, 60c, 60d, 60e, 60f, 60g are formed in the central portion of the first cover 40. In addition, for the purpose of reducing influence of the compressed refrigerant that is discharged from the discharge port 24, the multiple through holes 60a, 60b, 60c, 60d, 60d, 60e, 60f, and 60g may be provided along peripheral edge portions of the first top plate 42 of the first cover 40.

In the embodiment, the through hole 60a of the first cover 40 formed in the direction in which the compressed refrigerant is discharged from the discharge port 24 to the first space 46, is formed so that the diameter of the through hole 60a is smaller than the diameters of the other through holes 60b, 60c, 60d, 60e, 60f, 60g. This can prevent turbulence of the compressed refrigerant that is discharged from the discharge port 24 and thereby reduce noise and vibration. The motor element 30 includes an electric motor stator 32 fixed to the inner circumferential surface of the sealed container 10 through shrink fit or other method, an electric motor rotor 34 rotatably housed on an inner circumferential side of the electric motor stator 32, and the crankshaft 36 (main shaft portion 36a) fixed to the electric motor rotor 34 through shrink fit or other method. The electric motor rotor 34 is configured to rotate as electric power is supplied to the electric motor stator 32 and transmit a driving force to the orbiting scroll 26 through the crankshaft 36.

The eccentric shaft portion 36b located above the electric motor rotor 34 in the crankshaft 36 is rotatably supported in a radial direction by the cylindrical orbiting bearing 26c installed under the orbiting scroll base plate 26a. The main shaft portion 36a is fitted in a main bearing 39 and slides along the main bearing 39 by an oil film of a lubricating oil. The eccentric shaft portion 36b eccentric to the main shaft portion 36a is installed on the upper end of the crankshaft 36.

A pump element 19 such as a positive displacement pump is installed at a lower end of the crankshaft 36. The pump element 19 supplies the refrigerating machine oil accumulated in the oil sump 18 to the sliding parts such as the main bearing 39. The pump element 19 is mounted on the sub-frame 16 and supports the crankshaft 36 in the axial direction on an upper end surface of the pump element 19.

Next, an operation of the first cover 40 and the second cover 50 is described in details with reference to FIG.l to FIG.5. Arrows “A” in FIGG and FIG.5 indicate flows of the compressed refrigerant.

Firstly, while the compressor 1 is in operation, the compressed refrigerant is discharged from the discharge port 24 to the first space 46. The compressed refrigerant discharged from the discharge port 24 to the first space 46 flows in the first space 46 in the direction in which the compressed refrigerant is discharged from the discharge port 24 to the first space 46.

In the embodiment, since the through hole 60a of the first cover 40 formed in the direction in which the compressed refrigerant is discharged from the discharge port 24 to the first space 46, is formed so that the diameter of the through hole 60a is smaller than the diameters of the other through holes 60b, 60c, 60d, 60e, 60f, 60g, it is possible to prevent turbulence of the compressed refrigerant that is discharged from the discharge port 24 and to reduce noise and vibration.

Moreover, since the configuration surrounded by the first cover 40 and the second cover 50 includes the second space 56 that communicates only with the first space 46 and multiple through holes 60a, 60b, 60c, 60d, 60e, 60f, 60g that communicate between the first space 46 and the second space 56, the configuration surrounded by the first cover 40 and the second cover 50 forms a Helmholtz type resonance chamber communicating with the first space 46. As such, it is possible to reduce noise and vibration caused by discharge pulsation and the mechanical moving parts.

Furthermore, since multiple through holes 60a, 60b, 60c, 60d, 60e, 60f, 60g are formed to penetrate the first top plate 42 of the first cover 40 so that the through holes 60a, 60b, 60c, 60d, 60e, 60f, 60g with different diameters connect the first space 46 and the second space 56, the Helmholtz type resonance chamber that resonates at different specific frequencies with a simple configuration can be formed.

Secondly, the compressed refrigerant that reaches the first top plate 42, the compressed refrigerant flows toward the first peripheral wall 44 by changing the flow direction of the compressed refrigerant.

The first space 46 includes the plurality of chambers, each of which is surrounded by the extension portion 42a of the first top plate 42, the first peripheral wall 44 extending downward from the extension portion 42a, two bottom portions 48 and the top portion of the fixed scroll 22. As such, the plurality of chambers in the first space 46 function as refrigerant flow paths from the center potion of the first space 46 to the peripheral edge portion of the first space 46.

Moreover, each of the multiple extension portion 42a is formed to extend outward beyond the top portion of the fixed scroll 22 when the first cover 40 viewed from above, so as to form gaps 62 between parts of the lower end 44a of the first peripheral wall 44 and the top portion of the fixed scroll 22. As such, the compressed refrigerant that flows inside the refrigerant flow path that is surrounded by the extension portion 42a of the first top plate 42, the first peripheral wall 44, two bottom portions 48, can is discharged out of the first space 46.

As a result, since the first top plate 42 includes the multiple extension portion 42a and the first space 46 includes the multiple chambers, it is possible that the compressed refrigerant is smoothly discharged out of the first space 46 while preventing the occurrence of turbulence.

Therefore, according to the embodiment, the scroll compressor 1 can effectively reduce noise and vibration caused by discharge pulsation and mechanical moving parts with a simple configuration.

Although specific embodiments of the invention have been disclosed and described as well as illustrated in the companying drawings, it is simply for the purpose of better understanding of the principle of the present invention and it is not as a limitation of the scope and spirit of the teaching of the present invention. Adaption and modification to various structures such as design or material of the invention, mounting mechanism of various parts and elements or embodiments are possible and apparent to a skilled person without departing from the scope of the present invention which is to be determined by the claims.

List of reference:

1: scroll compressor

10: sealed container

10a: middle shell

12: suction pipe

14: discharge pipe

16: sub-frame

18: oil sump

19: pump element

20: compression mechanism

22: fixed scroll

22a: fixed scroll base plate

22b: fixed scroll spiral wrap

24: discharge port

26: orbiting scroll

26a: orbiting scroll base plate

26b: orbiting scroll spiral wrap

26c: orbiting bearing

28: compression chamber

30: motor element

32: electric motor stator

34: electric motor rotor

36: crankshaft

36a: main shaft portion

36b: eccentric shaft portion

39: main bearing

40: first cover

42: first top plate

42a: extension portion

44: first peripheral wall

44a: lower end of the first peripheral wall 46: first space

48: bottom portion

48a: opening

49: bolt 50: second cover

52: second top plate

54: second peripheral wall

54a: lower end of the second peripheral wall

56: second space 60, 60a, 60b, 60c, 60d. 603e, 60f, 60g: through hole

62: gap

A: flow of the compressed refrigerant