JP7728650B2 - Scroll fluid machinery - Google Patents

Description

This disclosure relates to a scroll fluid machine.

Scroll fluid machines, such as scroll compressors, generally comprise a fixed scroll member and an orbiting scroll member. The fixed scroll member has a spiral-shaped wall body that meshes with the orbiting scroll member, and the orbiting scroll member revolves around the fixed scroll, compressing and expanding the fluid in the sealed space defined by the walls.

For example, Patent Document 1 discloses a scroll compressor in which an intermediate member that acts as a vibration absorber and heat insulator is provided between the inner and outer housings.

Patent No. 5403004

The housing of a scroll fluid machine must be airtight to prevent refrigerant leakage and be able to withstand the pressure of the compressed refrigerant. Furthermore, while meeting these requirements, it is desirable to reduce the weight and noise of the housing.

This disclosure was made in light of these circumstances, and aims to provide a scroll fluid machine that is lightweight and reduces noise while ensuring airtightness and pressure resistance.

In order to solve the above problems, the scroll fluid machine of the present disclosure employs the following measures.
That is, a scroll fluid machine according to one aspect of the present disclosure comprises a compression mechanism having a fixed scroll and a revolving scroll, a crankshaft connected to the revolving scroll, a drive unit that drives the crankshaft to rotate around an axis, and a housing that accommodates the compression mechanism, the crankshaft, and the drive unit, wherein the housing has, in a radial direction relative to the axis, a metal layer, a resin layer, and a sound-absorbing layer, the metal layer being formed of a metal material, the resin layer being formed of a resin material that is lighter than the metal material that forms the metal layer and has a higher elastic modulus, the sound-absorbing layer being formed by arranging a plurality of cells that share the wall, each cell having a bottomed sound-absorbing space defined by a wall and an opening communicating with the sound-absorbing space, the resin layer being positioned radially outward of the metal layer, and each of the openings opening radially inward.

This disclosure makes it possible to achieve weight reduction and noise reduction while ensuring airtightness and pressure resistance.

1 is a longitudinal sectional view of a scroll fluid machine according to an embodiment of the present disclosure. FIG. 3 is a longitudinal cross-sectional view of the sound absorbing layer (sound absorbing cell) taken along the line III-III in FIG. 2.

Hereinafter, a scroll fluid machine according to an embodiment of the present disclosure will be described with reference to the drawings.
The scroll fluid machine of the present disclosure can be applied to a compressor and an expander, but the following description will be given taking a compressor as an example.

[Scroll compressor]
The scroll compressor 1 is a compressor provided in an air conditioning system mounted on a vehicle such as an electric vehicle or a hybrid vehicle.
As shown in FIG. 1 , the scroll compressor 1 includes a housing 10 , a compression mechanism 30 , a crankshaft 40 , and an electric motor (drive unit) 50 .

The housing 10 has a motor case 11, an upper case 15, and a lower case 16.

The motor case 11 is a cylindrical member that is open at both ends.
The motor case 11 accommodates the compression mechanism 30, the crankshaft 40, and the electric motor 50 therein.
The motor case 11 has a three-layer structure in the radial direction, and includes a metal layer 12, a resin layer 13, and a sound absorbing layer 14. The detailed structure of the motor case 11 will be described later.

The upper case 15 is a member that closes one of the open ends of the motor case 11 .
The upper case 15 is fixed to the metal layer 12 of the motor case 11 by bolts 71 .

The lower case 16 is a member that closes the other open end of the motor case 11 .
The lower case 16 is fixed to the metal layer 12 of the motor case 11 by bolts 72 .
An inverter cover 17 is attached to the lower case 16. An inverter (not shown) is housed in the space defined by the lower case 16 and the inverter cover 17.

The space defined by the housing 10 (motor case 11, upper case 15, and lower case 16) configured as described above houses the compression mechanism 30, crankshaft 40, electric motor 50, and various other devices.

The compression mechanism 30 is a mechanism that compresses low-pressure gas refrigerant taken in from outside the housing 10 .
The compression mechanism 30 includes a fixed scroll 31 and an orbiting scroll 32 .

The fixed scroll 31 is a member having a fixed end plate and a spiral-shaped fixed wall body standing upright from the end plate.
The fixed scroll 31 is fixed to the upper case 15 by a bolt 73 .

The orbiting scroll 32 is a member having an orbiting-side end plate and a spiral-shaped orbiting-side wall body standing upright from the end plate.
The orbiting scroll 32 is configured to revolve around the fixed scroll 31 by means of a crankshaft 40 that rotates about an axis X1 and a known rotation prevention mechanism.

The fixed scroll 31 and the orbiting scroll 32 have their respective walls meshed with each other to form a compression chamber 33 .
Gas refrigerant taken in from outside the housing 10 is guided into the compression chamber 33. The volume of the compression chamber 33 is gradually reduced by the orbital motion of the orbiting scroll 32, and the gas refrigerant is compressed accordingly.

The crankshaft 40 is a member for transmitting driving force from the electric motor 50 to the orbiting scroll 32 .
The crankshaft 40 has a shaft body 40a and a crank pin 40b.

Shaft body 40a is a shaft-shaped member extending along axis X1. Shaft body 40a is driven by electric motor 50 to rotate about axis X1.
The shaft body 40a is supported rotatably about the axis X1 by a main bearing 61 arranged on the upper case 15 side and a sub-bearing 62 arranged on the lower case 16 side.

The crank pin 40b is a shaft-shaped member provided at the end of the shaft body 40a.
The crank pin 40b extends along an axis X2 that is eccentric with respect to the axis X1.
The crank pin 40b is provided integrally with the shaft body 40a.

In the crankshaft 40 configured as described above, the crank pin 40b is connected to the orbiting scroll 32, and the shaft body 40a is driven to rotate around the axis X1 by the electric motor 50, thereby driving the orbiting scroll 32.

[Motor case configuration]
The motor case 11 has a three-layer structure including, in the radial direction relative to the axis X1, a metal layer 12, a resin layer 13, and a sound absorbing layer 14. The circumferential surfaces of the layers are in close contact with each other.

The metal layer 12 is a cylindrical member located on the innermost side of the three layers.
The metal layer 12 is made of a metal material, such as a lightweight metal material such as aluminum.
An upper flange portion 12a is formed on the end of the metal layer 12 facing the upper case 15, and a lower flange portion 12b is formed on the end of the metal layer 12 facing the lower case 16. A bolt 71 that secures the upper case 15 is fastened to the upper flange portion 12a. A bolt 72 that secures the lower case 16 is fastened to the lower flange portion 12b.

The resin layer 13 is a cylindrical member located outside the metal layer 12 .
The resin layer 13 may have an outer diameter smaller than the maximum outer diameter of the metal layer 12 (the outer diameter of the upper flange portion 12a and the lower flange portion 12b).
The resin layer 13 is made of a resin material that is lighter and has a higher elastic modulus than the metal material that forms the metal layer 12. Examples of the resin material include fiber-reinforced resins such as CFRP.

The sound absorbing layer 14 is a cylindrical member located on the outermost side of the three layers.
The outer diameter of the sound absorbing layer 14 may be smaller than the maximum outer diameter of the metal layer 12 (the outer diameter of the upper flange portion 12a and the lower flange portion 12b).
The sound absorbing layer 14 is formed of a fiber reinforced resin such as continuous fiber CFRP.

As shown in FIG. 2 , the sound absorbing layer 14 has a plurality of sound absorbing cells (cells) 20 arranged in a plane, and is capable of absorbing noise generated from the scroll compressor 1 .
The term "planar" used here means a curved surface that follows the outer peripheral surface of the resin layer 13.

As shown in Figures 2 and 3, the sound-absorbing cell 20 has a so-called honeycomb structure composed of an inner sheet 21, an outer sheet 22, and partition walls 23.

The inner sheet 21 is located on the inside of the sound-absorbing layer 14. That is, in Figure 1, the inner sheet 21 forms a surface that comes into close contact with the outer peripheral surface of the resin layer 13.

The outer sheet 22 is located on the outside of the sound-absorbing layer 14 and is spaced apart from the inner sheet 21.

The partition walls 23 connect the inner sheet 21 and the outer sheet 22 and form a hexagonal honeycomb structure.

The sound-absorbing cell 20 has a sound-absorbing space 24 defined by an inner sheet 21, an outer sheet 22, and partition walls 23. In the sound-absorbing space 24, the inner sheet 21 and outer sheet 22 correspond to the end surfaces (ceiling and bottom surfaces), and the partition walls 23 correspond to the side surfaces/periphery.

As shown in Figure 2, one sound absorbing cell 20 and its six adjacent sound absorbing cells are configured to share a partition wall 23. This results in the formation of a sound absorbing layer 14 in which multiple sound absorbing cells 20 are arranged in a planar fashion.

The inner sheet 21 is provided with openings 21 a that allow the outside of the inner sheet 21 to communicate with the sound absorbing space 24 .
One opening 21 a is provided for each sound absorbing space 24 .

The sound-absorbing cell 20 configured as described above acts as a so-called Helzholm resonator, which can absorb noise generated by the scroll compressor 1.

The sound-absorbing cell 20, which is a Helzholm resonator, has a sound-absorbing effect against sounds of a specific frequency, but the peak frequency of the noise generated by the scroll compressor 1 varies depending on the area (part) of the housing 10. For example, the peak frequencies of the noise differ between the housing 10 around the compression mechanism 30, the housing 10 around the main bearing 61, and the housing 10 around the electric motor 50.

Therefore, the frequency at which the sound absorbing cell 20 efficiently absorbs sound may be changed for each predetermined range along the axis X1.
Specifically, the frequency f at which the sound absorbing cell 20 efficiently absorbs sound is changed by changing the radius a of the opening 21a based on the following formula (1).

where:
f: Resonance frequency (frequency to be absorbed)
c: sound velocity; V: volume of the sound absorbing space 24; _ts : thickness of the inner sheet 21; a: radius of the opening 21a.

Equation (1) is the Helmholtz equation, and the resonant frequency f can be changed by changing various parameters (for example, V, t _s , a).
In this embodiment, the resonant frequency f can be easily changed by changing the radius a of the openings 21 a. Although the volume V of the sound absorbing space 24 or the thickness _ts of the inner sheet 21 can be changed, changing the radius a of the openings 21 a is the easiest method.

This embodiment provides the following advantages.
The housing 10 has, in the radial direction relative to the axis X1, a metal layer 12, a resin layer 13, and a sound-absorbing layer 14. The metal layer 12 is formed of a metal material, and the resin layer 13 is formed of a resin material that is lighter than the metal material forming the metal layer 12 and has a higher elastic modulus. The resin layer 13 is disposed radially outward of the metal layer 12, so that the metal layer 12 maintains the airtightness of the fluid machine while the resin layer 13 ensures pressure resistance. This reduces the load share of the metal layer 12 and reduces the stress applied to the metal layer 12. Furthermore, because the pressure resistance is ensured by the resin layer 13, the thickness of the metal layer 12 can be made thinner, thereby reducing the weight.

The sound-absorbing layer 14 is formed by arranging a plurality of sound-absorbing cells 20, each of which has a bottomed sound-absorbing space 24 defined by an inner sheet 21, an outer sheet 22, and a partition wall 23, and openings 21a communicating with the sound-absorbing space 24, so that they share a wall. Since each opening 21a opens radially inward, the sound-absorbing layer 14 acts as a so-called Helzholm resonator, absorbing noise generated by the scroll compressor 1.

In addition, because the sound-absorbing layer 14 is made of a resin material and is positioned at the outermost radial position, it can also function as a layer capable of absorbing external impacts. An example of an external impact would be impact from a flying stone or the like.

The sound-absorbing layer 14 may be positioned as the innermost of the three layers. However, the relationship in which the resin layer 13 is positioned on the outer side of the metal layer 12 remains unchanged.

The housing also has, in the axial direction, a motor case 11, an upper case 15, and a lower case 16. The motor case 11 has a metal layer 12, a resin layer 13, and a sound-absorbing layer 14. The upper case 15 and lower case 16 are fastened to the metal layer 12 of the motor case 11 with bolts, allowing the bolts 71 to be tightly fastened. If the bolts were fastened to the resin layer 13, there is a risk that the tightening force would decrease due to relaxation.

Furthermore, when the opening area of the aperture 21a is changed for each range along the direction of the axis X1, the frequency of sound that is efficiently absorbed can be changed depending on the range corresponding to the equipment housed in the housing 10 (e.g., the compression mechanism 30, main bearing 61, and electric motor 50).

The above-described embodiments can be understood, for example, as follows.
That is, a scroll fluid machine (1) according to one aspect of the present disclosure includes a compression mechanism (30) having a fixed scroll (31) and an orbiting scroll (32), a crankshaft (40) connected to the orbiting scroll, a drive unit (50) that drives the crankshaft to rotate around an axis, and a housing (10) that accommodates the compression mechanism, the crankshaft, and the drive unit, wherein the housing has a metal layer (12), a resin layer (13), and a sound-absorbing layer (14) in a radial direction relative to the axis, The metal layer is formed of a metal material, and the resin layer is formed of a resin material that is lighter and has a higher elastic modulus than the metal material that forms the metal layer. The sound-absorbing layer is formed by arranging a plurality of cells (20) that share the wall bodies (21, 22, 23) and have a bottomed sound-absorbing space (24) defined by the wall bodies and openings (21a) that communicate with the sound-absorbing space. The resin layer is positioned radially outward of the metal layer, and each of the openings opens radially inward.

In the scroll fluid machine according to this embodiment, the housing has, in the radial direction relative to the axis, a metal layer, a resin layer, and a sound-absorbing layer. The metal layer is formed from a metal material, and the resin layer is formed from a resin material that is lighter than the metal material forming the metal layer and has a higher elastic modulus. The resin layer is disposed radially outward of the metal layer, so that the metal layer maintains the airtightness of the fluid machine while the resin layer ensures pressure resistance. This reduces the load share of the metal layer and reduces the stress on the metal layer. Furthermore, because pressure resistance is ensured by the resin layer, the thickness of the metal layer can be made thinner, resulting in a lighter weight.

The sound-absorbing layer is formed by arranging multiple cells, each with a bottomed sound-absorbing space defined by a wall and an opening communicating with the sound-absorbing space, so that they share the wall. Each opening faces radially inward, so that the sound-absorbing layer acts as a so-called Helzholm resonator, absorbing noise generated by the scroll fluid machinery. Examples of cells include honeycomb cells.

In addition, in a scroll fluid machine according to one aspect of the present disclosure, the sound absorbing layer is formed from a resin material and is positioned at the outermost position in the radial direction.

In the scroll fluid machine according to this embodiment, the sound absorbing layer is made of a resin material and is positioned at the outermost radial position, so that the sound absorbing layer can also function as a layer capable of absorbing external impacts. An example of an external impact would be an impact from a flying stone or the like.

In addition, in a scroll fluid machine according to one aspect of the present disclosure, the housing has, in the axial direction, a motor case (11), an upper case (15), and a lower case (16), the motor case has the metal layer, the resin layer, and the sound-absorbing layer, and the upper case and the lower case are bolted to the metal layer of the motor case.

In the scroll fluid machine according to this aspect, the housing has, in the axial direction, a motor case, an upper case, and a lower case. The motor case has a metal layer, a resin layer, and a sound-absorbing layer. The upper case and lower case are fastened to the metal layer of the motor case with bolts, allowing the bolts to be tightly fastened. If the bolts were fastened to the resin layer, there is a risk that the tightening force would decrease due to relaxation.

In addition, in a scroll fluid machine according to one aspect of the present disclosure, the opening areas of the openings vary depending on the range along the axial direction.

In the scroll fluid machine according to this embodiment, when the opening area of the apertures is changed for each range along the axial direction, the frequency of sound that is efficiently absorbed can be changed depending on the range corresponding to the equipment housed in the housing (e.g., compression mechanism, bearings, electric motor).

REFERENCE SIGNS LIST 1 scroll compressor 10 housing 11 motor case 12 metal layer 12a upper flange portion 12b lower flange portion 13 resin layer 14 sound absorbing layer 15 upper case 16 lower case 17 inverter cover 20 sound absorbing cell (cell)
21 Inner sheet 21a Opening 22 Outer sheet 23 Partition wall 24 Sound absorbing space 30 Compression mechanism 31 Fixed scroll 32 Orbiting scroll 33 Compression chamber 40 Crankshaft 40a Shaft body 40b Crank pin 50 Electric motor (drive unit)
61 Main bearing 62 Sub-bearing 71, 72, 73 Bolt

Claims (4)

a compression mechanism having a fixed scroll and an orbiting scroll;
a crankshaft connected to the orbiting scroll;
a drive unit that drives the crankshaft to rotate around its axis;
a housing that accommodates the compression mechanism, the crankshaft, and the drive unit;
Equipped with
the housing has a metal layer, a resin layer, and a sound absorbing layer in a radial direction relative to the axis,
the metal layer is formed of a metal material,
the resin layer is formed of a resin material that is lighter and has a higher elastic modulus than a metal material that forms the metal layer;
the sound absorbing layer is formed by arranging a plurality of cells, each cell having a bottomed sound absorbing space defined by a wall body and an opening communicating with the sound absorbing space, so as to share the wall body;
the resin layer is disposed radially outward of the metal layer,
Each of the apertures opens inward in the radial direction,
The housing includes:
a cylindrical motor case having both ends open in the axial direction;
an upper case closing one open end of the motor case; and
a lower case closing the other open end of the motor case; and
and
Only the motor case has the metal layer, the resin layer, and the sound absorbing layer,
The metal layer, the resin layer, and the sound absorbing layer are in close contact with each other . A scroll fluid machine as described in claim 1, wherein the sound absorbing layer is formed from a resin material and is positioned at the outermost position in the radial direction. 3. The scroll fluid machine according to claim 1, wherein the upper case and the lower case are fastened to the metal layer of the motor case by bolts. 4. The scroll fluid machine according to claim 1, wherein the openings have different opening areas in different ranges along the axial direction.