Compressor and corrosion prevention method thereof

Abstract

To provide: a compressor capable of imparting corrosion resistance effect of a substantially equivalent degree to that of corrosion resistance coating, more simply than the corrosion resistance coating; and a corrosion prevention method thereof.SOLUTION: A compressor 1 of the present disclosure comprises: a metal-made housing 2 in which a first housing 21 and a second housing 22 are made to abut on each other to form a space; and a compressor 3 accommodated in the space. The first housing 21 and the second housing 22 are fastened to each other via fastening members 4, a seal member is arranged at a joining part of the first housing 21 and the second housing 22, abutment faces of the first housing 21 and the second housing 22 on an outer side of the seal member in a radial direction have separation regions which are separated from each other in a fastened state, and the separation regions are formed so as to surround an axial center of the housing 2 from multiple directions in an axial view.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a compressor and a method for preventing corrosion thereof. [Background technology]

[0002] A compressor used in an air conditioner has a compression mechanism housed in a sealed space within a housing, and compresses refrigerant gas taken into the sealed space. The housing comprises a front housing and a rear housing, which are butted together and then joined with multiple bolts to form a sealed space inside (see Patent Documents 1 and 2).

[0003] The joint between the front housing and the rear housing is sealed with an O-ring to keep the sealed space airtight (shaft seal structure). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2018 / 043151 [Patent Document 2] Japanese Patent Application Laid-Open No. 2017-172448 Summary of the Invention [Problem to be solved by the invention]

[0005] When a compressor such as that described in Patent Document 2 is used in a vehicle air conditioner, corrosion resistance must be taken into consideration when the vehicle travels in places where snow-melting agent (calcium chloride) has been spread or on the coast.

[0006] In on-board compressors, the adoption of a shaft seal structure is advantageous for miniaturization, but gaps are formed on the seal surface, making it prone to corrosion.

[0007] For example, if the housing near the O-ring corrodes and dissolves, the O-ring will no longer be able to maintain a tight seal, which could lead to refrigerant gas leaking and a decrease in compression capacity. For this reason, there is a strong demand for improved corrosion resistance near the sealing surface.

[0008] Possible methods for improving corrosion resistance include increasing the number of bolts, increasing the surface pressure on the sealing surfaces, or applying a corrosion-resistant coating, but all of these methods increase manufacturing costs.

[0009] For example, water glass is applied around the housing as a corrosion-resistant coating, but it is difficult to control the process and ensure the quality of the corrosion-resistant coating.

[0010] The present disclosure has been made in consideration of the above circumstances, and aims to provide a compressor and a corrosion prevention method thereof that are simpler than corrosion-resistant coatings and can achieve corrosion resistance effects comparable to those of corrosion-resistant coatings. [Means for solving the problem]

[0011] In order to solve the above problems, the compressor and the corrosion prevention method thereof of the present disclosure employ the following measures.

[0012] The present disclosure relates to a housing made of a metal material, including a first housing and a second housing butted together to form an internal space, and a compression mechanism housed in the space, wherein the first housing and the second housing are fastened to each other with a fastening member, a seal member is disposed at a joint between the first housing and the second housing, and abutting surfaces of the first housing and the second housing radially outward of the seal member have a separation region in a fastened state where they are spaced apart, and the separation region is provided so as to surround the axial center of the housing from multiple directions when viewed in the axial direction. The sacrificial material further includes a sacrificial material extending over the entire periphery between the abutting surfaces of the first housing and the second housing, the sacrificial material being a plate material of pure metal having a sacrificial anticorrosive effect on the metal material, the sacrificial material being disposed in close contact with the first housing and the second housing, the sacrificial material being in a gasket shape, and having an insertion hole for the fastening member. To provide a compressor.

[0013] The present disclosure relates to a corrosion prevention method for a compressor including a housing made of a metal material, in which a first housing and a second housing are butted together to form an internal space, and a compression mechanism housed in the space, the corrosion prevention method comprising: arranging a seal member at a joint between the first housing and the second housing; butting the first housing and the second housing together; and fastening the first housing and the second housing together with a fastening member; providing a separation region in which the butting surfaces of the first housing and the second housing are separated radially outward of the seal member; and arranging the separation region so as to surround the axial center of the housing from multiple directions when viewed in the axial direction. A sacrificial material is disposed over the entire periphery between the abutting surfaces of the first housing and the second housing, which are spaced apart from each other, and the sacrificial material is a gasket-shaped, pure metal plate having an insertion hole for the fastening member and having a sacrificial anticorrosion effect on the metal material, and the sacrificial material is disposed in close contact with the first housing and the second housing. The present invention provides a corrosion prevention method for a compressor.

[0014] The present disclosure provides a housing including a first housing and a second housing joined together to form a space therein, a compression mechanism housed in the space, and a sacrificial material extending over the entire periphery between the butted surfaces of the first housing and the second housing, wherein the first housing and the second housing are made of a metal material, the first housing and the second housing are joined by a fastening member, The sacrificial material is a plate of pure metal that has a sacrificial anticorrosive effect on the metal material, and the sacrificial material is disposed in close contact with the first housing and the second housing. The sacrificial material is in the shape of a gasket and has an insertion hole for the fastening member. To provide a compressor.

[0015] The present disclosure provides a corrosion prevention method for a compressor including a housing made of a metal material, in which a first housing and a second housing are butted together to form an internal space, and a compression mechanism housed in the internal space, the method comprising: The first housing and the second housing are joined by a fastening member, the housing is gasket-shaped, and has an insertion hole for the fastening member; and A pure metal plate having a sacrificial corrosion protection effect against the metal material is selected as the sacrificial material, and the plate is attached to the first housing and the second housing over the entire circumference between the butt surfaces of the first housing and the second housing so as to be in close contact with the first housing and the second housing. The aforementioned A method for protecting a compressor from corrosion by disposing a sacrificial material is provided. [Effects of the Invention]

[0016] According to the above disclosure, by providing a region that separates the mating surfaces of the first housing and the second housing when they are fastened together, it is possible to prevent saltwater from pooling and stagnating between the mating surfaces, thereby suppressing corrosion.

[0017] According to the above disclosure, the sacrificial material having a sacrificial anticorrosion effect corrodes preferentially to the housing, and therefore the progress of corrosion of the housing can be delayed in the vicinity of where the sacrificial material is disposed.

[0018] The sacrificial material is positioned so that it is in close contact with the first and second housings, which prevents any gaps from forming between the sacrificial material and the housings, preventing foreign matter from entering from the outside and suppressing refrigerant leakage from the inside.

[0019] Since the sacrificial material is a pure metal, it is easier to form it into a plate material, similar to the housing member, compared to powder.

[0020] Because the sacrificial material is a plate material, it is easier to assemble the housing than with anticorrosion treatment methods that involve pouring a liquid sealant into gaps. By placing the sacrificial material around the entire periphery, assembly and processing of the housing becomes easier.

[0021] According to the above disclosure, it is possible to obtain corrosion resistance effects equivalent to those of corrosion-resistant coatings more easily than with corrosion-resistant coatings, without increasing the number of bolts. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a vertical cross-sectional view of a compressor according to a first embodiment. [Figure 2] 2 is an enlarged view of a butt joint portion of the housing of the compressor of FIG. 1. [Figure 3] FIG. 10 is a schematic diagram of a rear housing in the case where separation regions are provided by dividing the rear housing into a plurality of regions. [Figure 4] FIG. 1 shows the results of a corrosion test. [Figure 5] FIG. 10 is a diagram showing a modified example of the first embodiment. [Figure 6] FIG. 6 is a vertical cross-sectional view of a compressor according to a second embodiment. [Figure 7] 7 is an enlarged view of a butt joint portion of the housing of the compressor of FIG. 6. [Figure 8] FIG. 1 is a schematic diagram of a sacrificial material. [Figure 9] FIG. 7 is a cross-sectional view taken along line YY in FIG. 6. [Figure 10] 10A and 10B are conceptual diagrams of the butt joint portion of the housing of the compressor according to the second embodiment before and after use. [Figure 11] FIG. 10 is a diagram showing the relationship between the potential difference and the degree of corrosion of the housing. [Figure 12] This is an image of corrosion at a conventional butt joint (with a narrow gap width σ). [Figure 13] 10A and 10B are conceptual diagrams of the butt joint portion of the housing before and after use of the compressor according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0023] Hereinafter, an embodiment of a compressor and a corrosion prevention method thereof according to the present disclosure will be described with reference to the drawings.

[0024] [First embodiment] In this embodiment, a scroll compressor constituting an air conditioner for a vehicle will be described.

[0025] Fig. 1 is a longitudinal sectional view of a compressor according to this embodiment, and Fig. 2 is an enlarged view of an abutting portion (I) of the housing of the compressor of Fig. 1.

[0026] The compressor 1 includes a housing 2 and a compression mechanism 3 .

[0027] The housing 2 includes a first housing and a second housing. In Fig. 1, the first housing is a cylindrical front housing 21 with a bottom, and the second housing is a rear housing 22 that closes the opening of the front housing 21.

[0028] The front housing 21 and the rear housing 22 are arranged with their ends 21E and 22E butting together as shown in Fig. 2. In this embodiment, the ends 21E and 22E are called butting surfaces, and the part where the ends 21E and 22E butt together is called an butting part.

[0029] The front housing 21 and the rear housing 22 are fastened to each other by fastening members, and a space S is formed inside the housing 2. The fastening members are bolts 4 or the like.

[0030] The front housing 21 and the rear housing 22 are joined at a joint (shaft seal surface 24) and are sealed by a seal member (for example, an O-ring) 23 to keep the space S sealed.

[0031] The housing 2 (front housing 21 and rear housing 22) is made of a metal material, such as a die-cast aluminum alloy containing aluminum as the main component, specifically an Al-Si-Cu aluminum alloy, for example, ADC12.

[0032] The mating surfaces (21E, 22E) of the front housing 21 and the rear housing 22 are located radially outward from the seal member 23. The radially outward side refers to the outer circumferential side of the housing 2, i.e., the side opposite the space S with respect to the seal member 23.

[0033] The housing 2 has a separation region where the abutting surfaces 21E and 22E are separated in the fastened state. The separation region is provided so as to surround the axial center of the housing from multiple directions when viewed in the axial direction.

[0034] The spaced apart region may be provided so as to continuously surround the entire axial center of the housing 2. The spaced apart region may be divided into a plurality of regions and provided so as to surround the axial center of the housing 2 intermittently.

[0035] When divided into multiple regions, each separation region is provided between the fastening members, avoiding the vicinity of the fastening members that fasten the front housing 21 and the rear housing 22 together. No separation region is provided near the bearing surfaces of the fastening members, and the abutting surfaces 21E, 22E are brought into close contact with each other over an area greater than that required to ensure fastening force. The total circumferential length of the separation regions occupies approximately half the angular area in the circumferential direction of the housing 2.

[0036] An example in which the separation region is provided by dividing the rear housing into a plurality of regions is shown in Fig. 3. Fig. 3 is a schematic cross-sectional view of the rear housing of Fig. 1 taken along line XX.

[0037] In Figure 3, the rear housing 22 has an insertion hole 6 into which a fastening member is inserted, a fastening surface 7, and a lower step surface 8. The fastening surface 7 is the surface of the area surrounding the insertion hole 6 and its vicinity. The lower step surface 8 is located slightly lower than the fastening surface 7. The lower step surface 8 is provided between one insertion hole 6 and another insertion hole 6 adjacent to it.

[0038] The sum of the circumferential lengths of the lower step surfaces 8 may be approximately half the circumferential length of the abutting surface 22E of the rear housing 22.

[0039] 3, when the rear housing 22 is butted against the front housing 21, the portion where the low step surface 8 is formed corresponds to the separation region 9. Because the low step surface 8 is recessed further than the fastening surface 7, when the rear housing 22 is butted against the front housing 21, it is separated from the butting surface 21E of the front housing 21.

[0040] In the separation region, the distance between the abutting surfaces (gap width σ) is 0.451 mm or more and 6 mm or less.

[0041] The compression mechanism 3 may have a fixed scroll 31 fixed to the rear housing 22 and an orbiting scroll 32 that revolves opposite the housing 2 and the fixed scroll 31 .

[0042] The fixed scroll 31 has a substantially circular end plate 311 and a spiral wall body (hereinafter referred to as the fixed scroll body) 312 erected on the end plate 311. The end plate 311 is fixed to the rear housing 22 with bolts 5. A discharge port 313 is formed in the approximate center of the end plate 311 for discharging compressed air to the rear side of the end plate 311 opposite the orbiting scroll 32. The fixed scroll body 312 protrudes perpendicularly from the surface of the end plate 311 facing the orbiting scroll 32 and is shaped along an involute curve (involute line) of a circle. A seal member 314 is provided on the protruding end face of the fixed scroll body 312.

[0043] Like the fixed scroll 31, the orbiting scroll 32 has a substantially disc-shaped end plate 321 and a spiral wall body (hereinafter referred to as the orbiting scroll body) 322 erected on the end plate 321. The back surface of the end plate 321 facing away from the fixed scroll 31 is supported so as to slidably face a thrust surface 221, which is the inner surface of the front housing 21. The orbiting scroll body 322 protrudes perpendicularly from the surface of the end plate 321 facing the fixed scroll 31, and has a shape that is 180° inverted from the shape of the fixed scroll body 312 of the fixed scroll 31. A seal member 323 is provided on the protruding end surface of the orbiting scroll body 322.

[0044] The orbiting scroll 32 and the fixed scroll 31 are arranged in the space S of the housing 2 so that the orbiting scroll 322 faces and meshes with the fixed scroll 312. In this arranged state, the seal member 323 of the orbiting scroll 322 contacts the surface of the end plate 311 of the fixed scroll 31, and the seal member 314 of the fixed scroll 312 contacts the surface of the end plate 321 of the orbiting scroll 32. As a result, a pair of multiple compression chambers P are formed between the orbiting scroll 32 and the fixed scroll 31, each partitioned by the end plate 321, the end plate 311, the orbiting scroll 322, and the fixed scroll 312.

[0045] The orbiting scroll 32 is configured to revolve around the fixed scroll 31 by an orbital mechanism. The orbital mechanism is composed of an input shaft 51, a crank pin 52, and a bush 53. The input shaft 51 is supported by a bearing 54 on the front housing 21 of the housing 2 so as to be rotatable about an axis C, with a tip end 51a extending outside the housing 2 and a base end 51b disposed in a space S within the housing 2. Rotational power is input to this input shaft 51 from outside the housing 2.

[0046] As the orbiting scroll 32 revolves relative to the fixed scroll 31, the volume of the pair of compression chambers P gradually decreases and they merge into one at the center of the end plate 311 of the fixed scroll 31. This increases the pressure in the compression chambers P, compressing the refrigerant gas (fluid) inside the chambers. The compressed refrigerant gas is discharged from a discharge port 313 formed in the end plate 311 of the fixed scroll 31.

[0047] The compressor 1 is not limited to being configured as the scroll compressor described above, but may be a rotary compressor whose compression mechanism compresses refrigerant gas (fluid) by eccentric rotation of a rotor. Furthermore, the compressor 1 may be configured to perform both scroll compression and rotary compression. Furthermore, the compressor 1 is configured to input rotational power from outside the housing 2, but may also have a drive unit (motor, etc.) inside the housing 2 (space S).

[0048] (Corrosion test) A salt spray test (STT) was carried out in accordance with JIS Z 2371 for the compressor in which the abutting surfaces were spaced apart according to the above embodiment.

[0049] Saltwater (neutral sodium chloride solution, 5%, 35°C) was sprayed onto a test machine simulating a compressor with varying gap widths σ, and an internal pressure of 0.3 MPa was applied. The progress of corrosion was evaluated by monitoring.

[0050] Housing metal material: Al-Si-Cu alloy Gap width: 0~2,000mm Test time: up to 240 hours Evaluation: Compare the corrosion progress of each gap at the time of leakage

[0051] The results of the corrosion test are shown in Figure 4. In this figure, the horizontal axis is the gap width (mm) and the vertical axis is the area of ​​metal loss (%). The area of ​​metal loss (%) was calculated by photographing the gap area with a stereo microscope, overlaying the photographed image on a mesh, and counting the areas of metal loss. The calculation formula is as follows: Thinning area = number of meshes in thinning area / total number of meshes × 100 [%]

[0052] The approximation curve interpolated in Figure 4 is based on equation (1).

number

[0053] According to Figure 4, the area of ​​metal loss initially increased as the gap width σ increased, and reached its maximum when the gap width σ was 0.1 mm. When the gap width σ exceeded 0.1 mm, the area of ​​metal loss gradually decreased. When the gap width σ was 0.451 mm or greater, the area of ​​metal loss was suppressed to 50% or less.

[0054] Results similar to those shown in Figure 4 were obtained with the actual device.

[0055] In the above embodiment, a housing having a structure in which the sealing member 23 is disposed in a cylindrical groove has been described, but the housing configuration is not limited to this. The above embodiment can also be applied to a housing having a structure shown in Fig. 5, for example. The housing having the structure shown in Fig. 5 is used in electric compressors and the like.

[0056] The housing in FIG. 5 has a structure in which a first housing 41 and a second housing 42 are arranged to abut against each other, and a seal member 43 (for example, a gasket) is arranged on the flat surface.

[0057] The first housing 41 is a housing body that houses the compressor. The second housing 42 is a lid that covers the opening of the housing body. The first housing 41 and the second housing 42 are fastened together by fastening members (not shown).

[0058] The mating surfaces of the first housing 41 and the second housing 42 are located radially outward of the seal member 43. In a fastened state, the mating surfaces are separated from each other by a gap width σ.

[0059] Second Embodiment This embodiment differs from the first embodiment in that a sacrificial material is disposed between the butted surfaces of the first housing and the second housing.

[0060] Fig. 6 is a vertical cross-sectional view of the compressor according to this embodiment, and Fig. 7 is an enlarged view of the butt joint portion of the housings of the compressor of Fig. 6.

[0061] The compressor 10 includes a housing 2, a compression mechanism 3, and a sacrificial material 16.

[0062] 6, the first housing is a cylindrical front housing 21 with a bottom, and the second housing is a rear housing 22 that closes the opening of the front housing 21.

[0063] The front housing 21 and the rear housing 22 are arranged with their ends 21E and 22E butting together, as shown in Fig. 7. In this embodiment, the ends 21E and 22E are called butting surfaces, and the portions where the ends 21E and 22E butt together are called butting portions. In this embodiment, the butting surfaces (ends 21E and 22E) are flat all around and do not have any steps.

[0064] The front housing 21 and the rear housing 22 are joined together with fastening members, forming a space S inside the housing 2. The fastening members are bolts 4 or the like.

[0065] The front housing 21 and the rear housing 22 are joined at a joint (shaft seal surface 24) and are sealed by a seal member (for example, an O-ring) 23 to keep the space S sealed.

[0066] The housing 2 (front housing 21 and rear housing 22) is made of a metal material, such as a die-cast aluminum alloy containing aluminum as the main component, specifically an Al-Si-Cu aluminum alloy, for example, ADC12.

[0067] A sacrificial material 16 extends over the entire periphery in the gap between the butt surfaces of the front housing 21 and the rear housing 22. The sacrificial material 16 is disposed on the outer circumferential side (radially outer side) of the housing 2 relative to the seal member 23, that is, on the side opposite the space S relative to the seal member 23.

[0068] The sacrificial material 16 is a plate of pure metal. As the pure metal, a single metal that has a sacrificial corrosion protection effect on the metal material that constitutes the housing 2 is selected. The selected pure metal has a higher ionization tendency than the metal material of the housing 2. "Sacrificial corrosion protection" means that by bringing a metal that has a higher ionization tendency than the base material into contact with the base material, the metal with the higher ionization tendency corrodes sacrificially, suppressing corrosion of the base material.

[0069] It is preferable to select a pure metal material that will make the potential difference between the sacrificial material 16 and the housing 2 0.28 [V vs. SCE] or less.

[0070] For example, when the metal material of the housing 2 is an aluminum alloy, the pure metal of the sacrificial material 16 may be selected from pure aluminum, pure zinc, and the like.

[0071] The sacrificial material 16 is arranged so as to be in close contact with the front housing 21 and the rear housing 22. The thickness of the sacrificial material 16 is selected depending on the gap between the front housing 21 and the rear housing 22 so that the sacrificial material 16 can be arranged in close contact. The thickness of the sacrificial material 16 may be 0.451 mm or more and 6 mm or less. Here, "close contact" means that no path for saltwater to enter is formed between the housing 21 and the sacrificial material 16. It is preferable that the thickness of the sacrificial material 16 is designed to be uniform around the entire periphery.

[0072] The sacrificial material 16 preferably has a shape corresponding to the abutting surfaces of the front housing 21 and the rear housing 22. In this way, the sacrificial material 16 fills the gap between the front housing 21 and the rear housing 22, and also makes it easier to generate surface pressure when fastened with fastening members.

[0073] Fig. 8 shows a schematic diagram of the sacrificial material applied to the compressor of Fig. 6. The sacrificial material 16 is preferably formed in a gasket shape. The gasket shape is a shape that can be sandwiched and compressed between the front housing 21 and the rear housing 22, sealing the gap and preventing the intrusion of liquid from the outside.

[0074] The sacrificial material 16 may be annular. The sacrificial material 16 may have an insertion hole 17 into which a fastening member for joining the front housing 21 and the rear housing 22 is inserted.

[0075] 9 shows a cross-sectional view taken along line YY in FIG. 6. The sacrificial material 16 has an outer shape that is substantially the same as the outer shape of the rear housing 22, and may have an inner hole 18 that is substantially the same diameter as the inner peripheral surface of the rear housing 22. The mating surfaces of the rear housing 22 and the front housing 21 usually have the same shape. By matching the outer shape of the sacrificial material 16 to the outer shape of the rear housing 22, the sacrificial material 16 can be positioned so that it does not protrude outside the housing 2.

[0076] The compression mechanism 3 may have a fixed scroll 31 fixed to the rear housing 22 and an orbiting scroll 32 that revolves opposite the housing 2 and the fixed scroll 31 .

[0077] The fixed scroll 31 has a substantially circular end plate 311 and a spiral wall body (hereinafter referred to as the fixed scroll body) 312 erected on the end plate 311. The end plate 311 is fixed to the rear housing 22 with bolts 5. A discharge port 313 is formed in the approximate center of the end plate 311 for discharging compressed air to the rear side of the end plate 311 opposite the orbiting scroll 32. The fixed scroll body 312 protrudes perpendicularly from the surface of the end plate 311 facing the orbiting scroll 32 and is shaped along an involute curve (involute line) of a circle. A seal member 314 is provided on the protruding end face of the fixed scroll body 312.

[0078] Like the fixed scroll 31, the orbiting scroll 32 has a substantially disc-shaped end plate 321 and a spiral wall body (hereinafter referred to as the orbiting scroll body) 322 erected on the end plate 321. The back surface of the end plate 321 facing away from the fixed scroll 31 is supported so as to slidably face a thrust surface 221, which is the inner surface of the front housing 21. The orbiting scroll body 322 protrudes perpendicularly from the surface of the end plate 321 facing the fixed scroll 31, and has a shape that is 180° inverted from the shape of the fixed scroll body 312 of the fixed scroll 31. A seal member 323 is provided on the protruding end surface of the orbiting scroll body 322.

[0079] The orbiting scroll 32 and the fixed scroll 31 are arranged in the space S of the housing 2 so that the orbiting scroll 322 faces and meshes with the fixed scroll 312. In this arranged state, the seal member 323 of the orbiting scroll 322 contacts the surface of the end plate 311 of the fixed scroll 31, and the seal member 314 of the fixed scroll 312 contacts the surface of the end plate 321 of the orbiting scroll 32. As a result, a pair of multiple compression chambers P are formed between the orbiting scroll 32 and the fixed scroll 31, each partitioned by the end plate 321, the end plate 311, the orbiting scroll 322, and the fixed scroll 312.

[0080] The orbiting scroll 32 is configured to revolve around the fixed scroll 31 by an orbital mechanism. The orbital mechanism is composed of an input shaft 51, a crank pin 52, and a bush 53. The input shaft 51 is supported by a bearing 54 on the front housing 21 of the housing 2 so as to be rotatable about an axis C, with a tip end 51a extending outside the housing 2 and a base end 51b disposed in a space S within the housing 2. Rotational power is input to this input shaft 51 from outside the housing 2.

[0081] As the orbiting scroll 32 revolves relative to the fixed scroll 31, the volume of the pair of compression chambers P gradually decreases and they merge into one at the center of the end plate 311 of the fixed scroll 31. This increases the pressure in the compression chambers P, compressing the refrigerant gas (fluid) inside the chambers. The compressed refrigerant gas is discharged from a discharge port 313 formed in the end plate 311 of the fixed scroll 31.

[0082] The compressor 10 is not limited to being configured as the scroll compressor described above, but may be a rotary compressor whose compression mechanism compresses the refrigerant gas (fluid) by eccentric rotation of a rotor. Furthermore, the compressor 10 may be configured to perform both scroll compression and rotary compression. Furthermore, the compressor 10 is configured to input rotational power from outside the housing 2, but may have a drive unit (motor, etc.) inside the housing 2 (space S).

[0083] The following describes the effects of the compressor and the corrosion prevention method thereof according to this embodiment.

[0084] 10 shows an image of the butt joint of the housing 2 (front housing 21 and rear housing 22) before and after use of the compressor according to this embodiment. In the figure, the left side of the arrow indicates before use, and the right side of the arrow indicates after use (when the sacrificial material has begun to decay due to corrosion).

[0085] The sacrificial material 16 corrodes preferentially to the butted surfaces of the housing 2. Therefore, the progress of corrosion of the housing 2 can be delayed around the butted portions where the sacrificial material 16 is arranged.

[0086] The sacrificial material 16 is disposed in close contact with the front housing 21 and the rear housing 22 so as to close the gap between them. Because there is no unnecessary gap between the sacrificial material 16 and the housing 2 (the front housing 21 and the rear housing 22), leakage of refrigerant from inside the housing 2 and entry of liquid from outside the housing 2 can be prevented, at least at the start of use.

[0087] Since the sacrificial material 16 is a pure metal, it is easier to form it into a plate material, similar to the housing member, compared to powder.

[0088] In this embodiment, the sacrificial material 16 is disposed continuously over 360° in the circumferential direction in the gap between the butt surfaces of the front housing 21 and the rear housing 22. Because the sacrificial material 16 is a plate material, assembly is easier than when anticorrosion treatment is performed using a liquid sealant. By disposing the sacrificial material 16 all around, assembly of the housing 2 becomes even easier.

[0089] The sacrificial material 16 can be applied to the gap region in the first embodiment. When the gap region is divided into a plurality of regions, the sacrificial material 16 may have a shape corresponding to each gap region.

[0090] (Corrosion test) A salt spray test (STT) was carried out in accordance with JIS Z 2371 for the compressor in which the sacrificial material was arranged according to the above embodiment.

[0091] Housing metal material: Aluminum alloy Sacrificial pure metal: pure aluminum plate (0.5 mm thick), pure zinc plate (0.5 mm thick) Shape of sacrificial material: Designed to be the same shape as the housing butt surface Gap width at butt joint (σ): 0.5 mm

[0092] Salt water (neutral sodium chloride solution, 5%, 35°C) was sprayed onto the butt joint of the housing where the sacrificial material was placed, and an internal pressure of 0.3 MPa was applied. After 500 hours, the compressor was dismantled and the state of corrosion was observed.

[0093] No noticeable corrosion was observed on the housing butt surfaces.

[0094] No noticeable corrosion was observed around the insertion holes of the fastening members of the sacrificial material (near the bolt tightening portion). This is thought to be because the high bolt surface pressure suppresses the occurrence of crevice corrosion. Because corrosion is suppressed near the bolt tightening portion, the risk of bolts falling off is low. Therefore, in the compressor according to the above embodiment, height adjustment in anticipation of bolts falling off is not required.

[0095] On the other hand, significant corrosion was observed in the intermediate areas between the insertion holes. This is thought to be due to the fact that the surface pressure applied by the bolts was lower at positions further away from the bolts, causing crevice corrosion.

[0096] (potential difference between the housing and the sacrificial material) Figure 11 shows the relationship between the potential difference and the corrosion progress of the housing. In this figure, the horizontal axis is the potential difference between the housing and the sacrificial material [V vs. SCE], and the vertical axis is the corrosion progress of the housing.

[0097] The pure aluminum (pure Al) sacrificial material was less corroded than the pure zinc (pure Zn) sacrificial material. On the other hand, the corrosion rate of the housing was slower when pure zinc sacrificial material was used.

[0098] It can be seen that if the potential difference between the sacrificial material and the housing is 0.28 [V vs. SCE] or less, the anticorrosive effect of the sacrificial material functions effectively and corrosion of the housing can also be suppressed.

[0099] The greater the potential difference with the housing, the greater the sacrificial anticorrosion effect of the sacrificial material. However, if the potential difference exceeds a threshold (excessive), the corrosion of the sacrificial material will proceed too quickly, shortening the time it takes for the sacrificial material to disintegrate. Since corrosion of the butt surfaces of the housing will progress once the sacrificial material disintegrates, it is better for the sacrificial material to remain in the gap for a long time while suppressing corrosion of the butt surfaces. If the potential difference between the sacrificial material and the housing is 0.28 [V vs SCE] or less, the anticorrosive effect of the sacrificial material will function effectively and corrosion of the housing will also be suppressed.

[0100] (Gap expansion effect) A salt spray test (STT) was conducted in accordance with JIS Z 2371 for compressors with different specifications for the gap at the butt joint between the front and rear housings.

[0101] Housing metal material: Aluminum alloy Gap width at butt joint σ: 0.01mm, 1mm

[0102] The butt joints of the housings were sprayed with 5% NaCl, and after 357 hours the compressor was disassembled and the state of corrosion was observed.

[0103] Figure 12 shows an image of the butt joint of a housing with a gap width σ of 0.01 mm before and after testing. In the figure, the left side of the arrow is before testing, and the right side is after testing.

[0104] In the housing with a gap width σ of 0.01 mm, corrosion had occurred up to the vicinity of the seal member 23. This is thought to be corrosion caused by saltwater that had entered the narrow gap, accumulated, stagnated, and concentrated. Note that the gap width σ in the conventional compressor is 0.01 mm.

[0105] On the other hand, in the housing with a gap width σ of 1 mm, slight corrosion was observed at the butt surface of the front housing 21 and the rear housing 22, but the progression of corrosion was less than in Figure 12. This is thought to be because the enlarged gap at the butt joint prevented saltwater from stagnating and concentrating in the gap, thereby suppressing corrosion.

[0106] 13 shows an image of the butt joint of the housings of the compressor according to this embodiment before and after use. In the figure, the left side of the arrow indicates the state before use, and the right side of the arrow indicates the state after use.

[0107] According to the compressor of this embodiment, the sacrificial material 16 is disposed in close contact with the butt joint between the front housing 21 and the rear housing 22, thereby preventing refrigerant leakage from the inside and saltwater from entering from the outside. This physically suppresses corrosion of the housing in the early stages of use.

[0108] Even if saltwater gets in between the sacrificial material 16 and the housing 2, the sacrificial material 16 has a sacrificial anticorrosion effect on the housing 2, so corrosion of the housing 2 is suppressed as long as the sacrificial material 16 is present.

[0109] Corrosion does not progress easily near the fastening member insertion holes 17 because the sacrificial material 16 is strongly compressed by the fastening of the fastening member. On the other hand, the sacrificial material 16 located away from the insertion holes 17 will disintegrate and eventually disappear as corrosion progresses. However, by using sacrificial material 16 with a thickness of 0.451 mm or more, even when the sacrificial material 16 is no longer present, a gap width σ of 0.451 mm or more corresponding to the thickness of the sacrificial material 16 remains between the front housing 21 and the rear housing 22. This gap has a configuration corresponding to the separation region in the first embodiment. With a gap width σ of 0.451 mm or more, saltwater is less likely to stagnate and concentrate, so corrosion of the housing 2 is suppressed even after the sacrificial material 16 disintegrates.

[0110] It is desirable that the gap width σ is a constant gap in the axial direction around the entire circumference of the housing, and therefore it is advisable to design the thickness of the sacrificial material 16 to be uniform.

[0111] <Additional Notes> The compressor and the corrosion prevention method thereof described in the above-described embodiment can be understood, for example, as follows.

[0112] The present disclosure provides a compressor (1) comprising: a housing (2) made of a metal material, in which a first housing (21) and a second housing (22) are butted together to form a space (S) therein; and a compression mechanism (3) accommodated in the space, wherein the first housing and the second housing are fastened to each other with a fastening member (4), a seal member (23) is disposed at the joint between the first housing and the second housing, and abutting surfaces (21E, 22E) of the first housing and the second housing radially outward of the seal member have a separation region (9) in which they are spaced apart in a fastened state, and the separation region is arranged to surround the axial center of the housing from multiple directions when viewed in the axial direction.

[0113] The present disclosure provides a corrosion protection method for a compressor that includes a housing made of a metal material, where a first housing and a second housing are butted together to form a space inside, and a compression mechanism housed in the space, wherein a sealing member is placed at the joint between the first housing and the second housing, the first housing and the second housing are butted together, and the first housing and the second housing are fastened to each other with a fastening member, and a separation region is provided in which the butting surfaces of the first housing and the second housing are separated radially outside the sealing member, and the separation region is positioned so as to surround the axial center of the housing from multiple directions when viewed in the axial direction.

[0114] According to the above disclosure, by providing a separation region that separates the mating surfaces of the first housing and the second housing in a fastened state, it is possible to prevent saltwater from pooling and stagnating between the mating surfaces, thereby suppressing corrosion.

[0115] The spaced apart region may surround the entire circumference of the axial center of the housing, or may be divided into a plurality of regions with a total circumferential length that is approximately half the angular region in the circumferential direction.

[0116] When divided into multiple regions, each separation region is positioned between adjacent fastening members. No separation region is provided near the seating surfaces of the fastening members, and the butting surfaces are tightly attached to each other. By making the circumferential length of each separation region approximately half the angular area of ​​the housing's circumference, the butting surfaces can be tightly attached to each other near the seating surfaces of the fastening members over an area necessary to ensure fastening force. In the fastened state, the surface pressure is high near the seating surfaces of the fastening members. Therefore, even if no separation region is provided, saltwater is less likely to penetrate, and corrosion is suppressed.

[0117] According to the above disclosure, it is possible to obtain corrosion resistance effects equivalent to those of corrosion-resistant coatings more easily than with corrosion-resistant coatings, without increasing the number of bolts.

[0118] In one aspect of the disclosure, the distance (gap width σ) between the butting surfaces of the first housing and the second housing in the isolation region may be 0.451 mm or more and 6 mm or less.

[0119] By setting the gap width σ to 0.451 mm or more, the area of ​​metal loss due to corrosion in the gap can be reduced to 50% or less. From the viewpoint of processing, it is preferable that the gap width σ be 6 mm or less.

[0120] In one embodiment of the above disclosure, the device further includes a sacrificial material (6) extending around the entire periphery between the abutting surfaces of the first housing and the second housing, which are spaced apart, and the sacrificial material is a plate of pure metal that has a sacrificial anticorrosive effect on the metal material, and the sacrificial material can be arranged in close contact with the first housing and the second housing.

[0121] The sacrificial material having a sacrificial anticorrosion effect corrodes preferentially to the housing, and therefore the progress of corrosion of the housing can be delayed in the vicinity where the sacrificial material is disposed.

[0122] The sacrificial material is arranged so as to be in close contact with the first and second housings, which prevents any unnecessary gaps between the sacrificial material and the housings, preventing refrigerant leakage from the inside and liquid from entering from the outside.

[0123] Since the sacrificial material is a pure metal, it is easier to form it into a plate material, similar to the housing member, compared to powder.

[0124] Since the sacrificial material is a plate material, corrosion prevention measures are easier than with a method of corrosion prevention treatment using a liquid sealant. The sacrificial material may be annular. By disposing the sacrificial material around the entire periphery, assembly processing of the housing becomes easier.

[0125] In one aspect of the disclosure, the sacrificial material may be in the shape of a gasket and have an insertion hole for the fastening member.

[0126] The sacrificial material is sandwiched between the first and second housings. When the first and second housings are joined by a fastening member, the sacrificial material is compressed particularly strongly around the fastening member insertion holes. This makes it difficult for foreign matter to enter the area around the insertion holes. As a result, the housing and sacrificial material are less likely to corrode the closer they are to the part fastened by the fastening member.

[0127] The gasket-shaped sacrificial material is sandwiched between the first and second housings and compressed to fill the gap between the first and second housings and prevent liquid from entering from the outside.

[0128] By using a gasket shape, the sacrificial material can be positioned so that it fits within the outer periphery of the housing. By preventing the sacrificial material from protruding beyond the housing, the sacrificial material can be positioned with minimal structural changes to the compressor.

[0129] The present disclosure provides a compressor (10) comprising a housing (2) in which a first housing (21) and a second housing (22) are butted together and joined to form a space (S) therein, a compression mechanism (3) housed in the space, and a sacrificial material (6) extending around the entire periphery between the butt surfaces of the first housing and the second housing, wherein the first housing and the second housing are made of a metallic material, the sacrificial material is a plate of pure metal that has a sacrificial anticorrosive effect on the metallic material, and the sacrificial material is disposed in close contact with the first housing and the second housing.

[0130] The present disclosure provides a corrosion protection method for a compressor that includes a housing made of a metallic material, where a first housing and a second housing are butted together to form a space inside, and a compression mechanism housed in the space, in which a pure metal plate that has a sacrificial anticorrosive effect on the metallic material is selected as a sacrificial material, and the sacrificial material is arranged around the entire circumference between the butt surfaces of the first housing and the second housing so as to be in close contact with the first housing and the second housing.

[0131] The sacrificial material having a sacrificial anticorrosion effect corrodes preferentially to the housing, and therefore the progress of corrosion of the housing can be delayed in the vicinity where the sacrificial material is disposed.

[0132] The sacrificial material is arranged so as to be in close contact with the first and second housings, which prevents any unnecessary gaps from forming between the sacrificial material and the housings, preventing refrigerant leakage from the inside and liquid from entering from the outside.

[0133] Since the sacrificial material is a pure metal, it is easier to form it into a plate material, similar to the housing member, compared to powder.

[0134] Since the sacrificial material is a plate material, it is easier to take anti-corrosion measures compared to the method of anti-corrosion treatment using a liquid sealant. The sacrificial material may be annular. By disposing the sacrificial material around the entire periphery, assembly and processing of the housing becomes easier.

[0135] In one aspect of the disclosure above, the first housing and the second housing may be joined by a fastening member, and the sacrificial material may be gasket-shaped and have an insertion hole (7) for the fastening member.

[0136] The sacrificial material is sandwiched between the first and second housings. When the first and second housings are joined by a fastening member, the sacrificial material is compressed particularly strongly around the fastening member insertion holes. This makes it difficult for foreign matter to enter the area around the insertion holes. As a result, the housing and sacrificial material are less likely to corrode the closer they are to the part fastened by the fastening member.

[0137] The gasket-shaped sacrificial material is sandwiched between the first and second housings and compressed to fill the gap between the first and second housings and at the same time prevent liquid from entering from the outside.

[0138] By using a gasket shape, the sacrificial material can be positioned so that it fits within the outer periphery of the housing. By preventing the sacrificial material from protruding beyond the housing, the sacrificial material can be positioned with minimal structural changes to the compressor.

[0139] In one aspect of the disclosure above, the sacrificial material may have a shape corresponding to the abutting surfaces of the first housing and the second housing.

[0140] "Corresponding to the abutment surfaces" means that the outer shape, inner shape, and surface are designed to have the same shape as the abutment surfaces. A sacrificial material shaped to correspond to the abutment surfaces is likely to adhere to the first housing and the second housing. A sacrificial material with outer and inner shapes corresponding to the abutment surfaces can be positioned to fit within the outer periphery of the housing.

[0141] In one embodiment of the above disclosure, the thickness of the sacrificial material may be 0.451 mm or more and 6 mm or less.

[0142] The effect of widening the gap can be ensured by making the sacrificial material 0.451 mm or thicker. If the sacrificial material is 6 mm or thinner, it can be processed into a plate.

[0143] The thickness of the sacrificial material is preferably uniform.

[0144] In one embodiment of the disclosure above, the potential difference between the sacrificial material and the housing may be 0.28 [V vs. SCE] or less.

[0145] By keeping the potential difference between the sacrificial material and the housing at 0.28 [V vs SCE] or less, corrosion of the housing butt surfaces can be suppressed while allowing the sacrificial material to remain in the gap between the butt surfaces for a longer period. It is presumed that if the potential difference is too large, corrosion of the sacrificial material will progress more quickly, shortening the period during which the sacrificial corrosion protection effect can be obtained. However, if the potential difference is 0.28 [V vs SCE] or less, the above-mentioned effect can be reliably obtained. [Explanation of symbols]

[0146] 1,10 Compressor 2. Housing 3. Compression mechanism 4.5 volts 6 Insertion hole (provided in the rear housing) 7 Fastening Surface 8 Low level surface 9 Separation area 16 Sacrificial material 17 Insertion hole (provided in the sacrificial material) 18 Inner hole 21 Front housing (first housing) 21E (Front housing) end, butt surface 22 Rear housing (second housing) 22E (rear housing) end, butt surface 23,43 Sealing member 24 Shaft seal surface (joint) 31 Fixed Scroll 32 Swivel Scroll 41 First Housing 42 Second Housing 51 Input shaft 51a tip 51b Proximal end 52 crank pin 53 Bush 54 bearings 221 Thrust surface 311 (Fixed scroll) end plate 312 (Fixed scroll) wall, fixed scroll 313 Discharge port 314 (Fixed scroll) sealing member 321 (orbiting scroll) end plate 322 (of a rotating scroll) wall, rotating scroll 323 (orbiting scroll) sealing member

Claims

1. a housing made of a metal material, the housing including a first housing and a second housing that are butted together to form a space therein; a compression mechanism housed within the space; Equipped with the first housing and the second housing are fastened to each other by a fastening member, a seal member is disposed at a joint between the first housing and the second housing; a separation region in which abutting surfaces of the first housing and the second housing radially outward from the seal member are separated in a fastened state; the separation region is provided so as to surround the axial center of the housing from multiple directions when viewed in the axial direction, a sacrificial material extending around the entire periphery between the spaced apart mating surfaces of the first housing and the second housing; the sacrificial material is a pure metal plate having a sacrificial anticorrosion effect on the metal material, the sacrificial material is disposed in close contact with the first housing and the second housing; The sacrificial material is in the shape of a gasket and has an insertion hole for the fastening member.

2. The compressor according to claim 1 , wherein a distance between the abutting surfaces of the first housing and the second housing in the separation region is equal to or greater than 0.451 mm and equal to or less than 6 mm.

3. a housing in which a first housing and a second housing are butted together and joined to form a space therein; a compression mechanism housed within the space; a sacrificial material extending over the entire periphery between the butt surfaces of the first housing and the second housing; Equipped with the first housing and the second housing are made of a metal material, the first housing and the second housing are joined by a fastening member, the sacrificial material is a pure metal plate having a sacrificial anticorrosion effect on the metal material, the sacrificial material is disposed in close contact with the first housing and the second housing; The sacrificial material is in the shape of a gasket and has an insertion hole for the fastening member.

4. 4. The compressor according to claim 1, wherein the sacrificial material has a shape corresponding to the abutting surfaces of the first housing and the second housing.

5. The compressor according to claim 3 or 4, wherein the thickness of the sacrificial material is 0.451 mm or more and 6 mm or less.

6. The compressor according to any one of claims 1 to 5, wherein a potential difference between the sacrificial material and the housing is 0.28 [V vs SCE] or less.

7. A corrosion prevention method for a compressor including a housing made of a metal material, the housing including a first housing and a second housing butted together to form an internal space, and a compression mechanism housed in the internal space, the method comprising: a seal member is disposed at a joint between the first housing and the second housing; The first housing and the second housing are butted together, a separation region is provided in which abutting surfaces of the first housing and the second housing are separated from each other radially outward of the seal member when the first housing and the second housing are fastened to each other by a fastening member; The separation region is disposed so as to surround the axial center of the housing from multiple directions when viewed in the axial direction, A sacrificial material is extended over the entire periphery between the abutting surfaces of the first housing and the second housing, which are spaced apart from each other; the sacrificial material is a gasket-shaped, pure metal plate having an insertion hole for the fastening member and having a sacrificial anticorrosion effect on the metal material, The corrosion prevention method for a compressor includes disposing the sacrificial material in close contact with the first housing and the second housing.

8. A corrosion prevention method for a compressor including a housing made of a metal material, the housing including a first housing and a second housing butted together to form an internal space, and a compression mechanism housed in the internal space, the method comprising: The first housing and the second housing are joined together with a fastening member; A gasket-shaped, pure metal plate having an insertion hole for the fastening member and having a sacrificial anticorrosion effect on the metal material is selected as the sacrificial material; A corrosion protection method for a compressor, comprising: arranging the sacrificial material over the entire periphery between the abutting surfaces of the first housing and the second housing so as to be in close contact with the first housing and the second housing.

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