Scroll compressor and method for manufacturing same

Abstract

A cylindrical main shell (11) that houses a compression mechanism unit (3) having a fixed scroll (31) and an orbiting scroll (32), a frame (2) for slidably holding the orbiting scroll (32), and a driv

Description

PROBLEM TO BE SOLVED BY THE INVENTION

[0004] However, in the scroll compressor according to Patent Document 1, when a straight tube part of the main shell, as a first straight tube part and a second straight tube part of the main shell, is being enlarged in the radial direction, stress that occurs inside the main shell is increased. Thus, there is a problem that the increased stress reaches the tensile strength of material forming the main shell and thus the main shell breaks.

[0005] The present disclosure has been made to solve the above problem, and an object of the present disclosure is to provide a scroll compressor having a configuration capable of suppressing breakage of a main shell. MEANS TO SOLVE THE PROBLEM

[0006] A scroll compressor according to the present disclosure includes: a compression mechanism portion having a fixed scroll and an orbiting scroll; a frame slidably retaining the orbiting scroll; a drive mechanism portion which slides the orbiting scroll; and a tube-shaped main shell storing therein the compression mechanism portion, the frame, and the drive mechanism portion. The main shell includes a first straight tube part extending along the center axis, a second straight tube part extending along the center axis and having a smaller outer diameter than the first straight tube part, and a third straight tube part extending along the center axis and having a smaller outer diameter than the second straight tube part. The fixed scroll is fixed in the first straight tube part, the frame is fixed in the second straight tube part, and the drive mechanism portion is fixed in the third straight tube part. EFFECT OF THE INVENTION

[0007] In the scroll compressor according to the present disclosure, using the second straight tube part as a reference, the diameter of the first straight tube part is enlarged and the diameter of the third straight tube part is reduced, whereby breakage of the main shell can be suppressed, even if the ratio of the outer diameter of the first straight tube part and the outer diameter of the third straight tube part of the main shell exceeds the strain amount corresponding to the tensile strength of material forming the main shell. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] [FIG. 1] FIG. 1 is a perspective view of a scroll compressor according to embodiment 1. [FIG. 2] FIG. 2 is a sectional view of the scroll compressor according to embodiment 1. [FIG. 3] FIG. 3 is a perspective view of a major part of a main shell according to embodiment 1. [FIG. 4] FIG. 4 is an enlarged view of an area surrounded by a broken line in FIG. 2. [FIG. 5] FIG. 5 is an enlarged sectional view of the main shell according to embodiment 1. [FIG. 6] FIG. 6 is an enlarged sectional view of the main shell according to embodiment 1. [FIG. 7] FIG. 7 is an enlarged sectional view of the main shell according to embodiment 1. [FIG. 8] FIG. 8 is an enlarged sectional view of the main shell according to embodiment 1. [FIG. 9] FIG. 9 is a perspective view of a specific part of a first frame according to embodiment 1. [FIG. 10] FIG. 10 is a perspective view of a specific part of a fixed scroll according to embodiment 1. [FIG. 11] FIG. 11 is a perspective view of a specific part of an orbiting scroll according to embodiment 1. [FIG. 12] FIG. 12 is a perspective view of an Oldham ring according to embodiment 1. [FIG. 13] FIG. 13 is a perspective view of a crankshaft according to embodiment 1. [FIG. 14] FIG. 14 is a perspective view of a bush according to embodiment 1. [FIG. 15] FIG. 15 illustrates a dimensional relationship in the broken-line-area, shown in FIG. 4, of the main shell. DESCRIPTION OF EMBODIMENTS

[0009] Hereinafter, a preferred embodiment of a scroll compressor according to the present disclosure will be described with reference to the drawings. The same or corresponding matters or parts are denoted by the same reference characters, and the detailed description thereof is omitted. Also in other embodiments, components denoted by the same reference characters will not be repeatedly described.

[0010] Embodiment 1 FIG. 1 is a perspective view of a scroll compressor, and FIG. 2 is a schematic vertical sectional view of the scroll compressor according to embodiment 1. The compressor of FIG. 1 is a so-called vertical-type scroll compressor to be used in a state in which a main shaft portion 61 (center axis) of a crankshaft is substantially perpendicular to the ground surface. In the following description, the vertical-type scroll compressor shown in FIG. 1 is referred to as scroll compressor.

[0011] The scroll compressor includes a shell 1, a first frame 2, a compression mechanism portion 3, a drive mechanism portion 4, a second frame 5, a crankshaft 6, a bush 7, and a power supply portion 8. In the following description, using the first frame 2 as a reference, the side where the compression mechanism portion 3 is provided (upper side) is defined as a U side, and the side where the drive mechanism portion 4 is provided (lower side) is defined as an L side. In FIG. 2, the first frame 2, the compression mechanism portion 3, and the crankshaft 6 are not directly shown. However, components of the first frame 2, the compression mechanism portion 3, and the crankshaft 6 are respectively denoted so as to correspond to the first digits of the reference characters thereof.

[0012] The shell 1 is a housing made of metal and closed at both ends, and includes a main shell 11, an upper shell 12, and a lower shell 13. The main shell 11 has a cylindrical shape, and a suction pipe 14 is connected to the side wall thereof by welding or the like.

[0013] In FIG. 2, the suction pipe 14 is a pipe for introducing a refrigerant into the shell 1, and communicates with the inside of the main shell 11. The upper shell 12 has a substantially hemispherical shape, a part of the side wall thereof is connected to the upper end of the main shell 11 by welding or the like, and the upper shell 12 covers the upper opening of the main shell 11. A discharge pipe 15 is connected to an upper part of the upper shell 12 by welding or the like. The discharge pipe 15 is a pipe for discharging the refrigerant to the outside of the shell 1, and communicates with the internal space of the main shell 11.

[0014] The lower shell 13 has a substantially hemispherical shape, a part of the side wall thereof is connected to the lower end of the main shell 11 by welding or the like, and the lower shell 13 covers the lower opening of the main shell 11. The shell 1 is supported by a fixation base 16 having a plurality of screw holes. In the fixation base 16, a plurality of screw holes are formed and screws are screwed into the screw holes, whereby the scroll compressor can be fixed to another member such as a housing of an outdoor unit.

[0015] Hereinafter, each component will be described in detail. <Configuration of main shell 11> In the main shell 11 shown in FIG. 1 and FIG. 2, for simplification, the main shell 11 is shown so as to have a cylindrical shape, and change in an inner diameter and an outer shape of the main shell 11 is omitted. However, the outer shape structure of the main shell 11 has the following characteristics .

[0016] As shown in FIG. 3, the main shell 11 includes: a first protruding portion 112 which has a second inner wall surface 114 protruding in the radial direction from a first inner wall surface 111; a first positioning surface 113 which is an end surface, facing the upper shell 12 side, of the first protruding portion 112, and which contacts with a first base plate 311 (see FIG. 10 described later) of a fixed scroll 31 shown in FIG. 2 so as to determine the axial-direction position of the fixed scroll 31; a second protruding portion 115 which has a third inner wall surface 117 further protruding in the radial direction relative to the first protruding portion 112; and a second positioning surface 116 which is an end surface, facing the upper shell 12 side, of the second protruding portion 115 and which contacts with a body portion 21 of the first frame 2 so as to determine the axial-direction position of the first frame 2. That is, the main shell 11 has a stepwise part with the inner diameter reduced toward the L side shown in FIG. 2.

[0017] The first positioning surface 113 and the second positioning surface 116 are substantially perpendicular to the center axis of the crankshaft 6, and the normal vectors of both positioning surfaces are set so as to be directed in the same direction.

[0018] Further, the first protruding portion 112 has a groove 118 which is fitted with a projection 314 (see FIG. 10 described later) of the fixed scroll 31 and a projection 216 (see FIG. 9 described later) of the first frame 2 and determines the phases of both components. The end on the upper shell 12 side of the groove 118 has C chamfered or R chamfered portions 1181, so that the groove width is gradually narrowed from the end. Thus, the chamfered portions 1181 serve as a guide so that the projection 216 of the first frame 2 and the projection 314 of the fixed scroll 31 are guided, whereby assembly can be easily performed and assemblability of the compressor is improved.

[0019] FIG. 4(a) is an enlarged view of an area surrounded by a broken line in FIG. 2, and enlarged views of an area A and an area B surrounded by circles in FIG. 4(a) are FIG. 4(b) and FIG. 4(c), respectively. As seen in FIG. 4(b) and FIG. 4(c), a recess 1131 is formed at a corner where the first positioning surface 113 and the first inner wall surface 111 intersect each other, and a recess 1161 is formed at a corner where the second positioning surface 116 and the second inner wall surface 114 intersect each other. Thus, the fixed scroll 31 and the first frame 2 can be assuredly brought into contact with the respective positioning surfaces .

[0020] The main shell 11 may be manufactured as a welded steel tube by shaping a plate steel material into a tube shape through rolling or pressing and connecting the seam by welding so as to be a steel tube. In this case, if the groove 118 is formed at a part other than the welded seam part, the groove can be formed without losing reliability of the main shell 11.

[0021] Next, the structure of a wall surface of the main shell 11 will be described in more detail with respect to cross sections shown in FIG. 5 and FIG. 6. FIG. 6 shows a cross section in a state in which the first frame 2, the compression mechanism portion 3, and the drive mechanism portion 4 are mounted to the main shell 11 of FIG. 5. The main shell 11 includes a first straight tube part 1111, a second straight tube part 1112, and a third straight tube part 1113 from the U side in this order, and is demarcated by a first connection portion 1117 connecting the first straight tube part 1111 and the second straight tube part 1112, and a second connection portion 1118 connecting the second straight tube part 1112 and the third straight tube part 1113. Since the main shell 11 has a cylindrical shape, the same cross-sectional configuration as those shown in FIG. 5 and FIG. 6 is also formed on the opposite side with respect to the center axis of the crankshaft.

[0022] The relationship among an outer diameter DI of the first straight tube part 1111 of the main shell 11, an outer diameter D2 of the second straight tube part 1112 of the main shell 11, and an outer diameter D3 of the third straight tube part 1113 of the main shell 11 satisfies D1>D2>D3. In addition, the first straight tube part 1111 of the main shell 11 is disposed in a position including the first inner wall surface 111 where the fixed scroll 31 is fitted with the main shell 11. The second straight tube part 1112 of the main shell 11 is disposed in a position including the second inner wall surface 114 where the body portion 21 of the first frame 2 is fitted with the main shell 11.

[0023] For example, the first straight tube part 1111, the second straight tube part 1112, the third straight tube part 1113, the first connection portion 1117, and the second connection portion 1118 of the main shell 11 are formed through press working or the like. That is, using the second straight tube part 1112 extending along the center axis of the crankshaft 6 as a reference, the first straight tube part 1111 extending along the center axis is formed so as to have a larger inner diameter than the second straight tube part 1112, and the third straight tube part 1113 extending along the center axis is formed so as to have a smaller inner diameter than the second straight tube part 1112. At this time, a first working mark 1119 which is formed when an inner circumferential part or an outer circumferential part of the first straight tube part 1111 of the main shell 11 is pressed by a jig or the like, remains on the inner circumferential part or the outer circumferential part. Similarly, a second working mark 1120 remains on an inner circumferential part or an outer circumferential part of the second straight tube part 1112 of the main shell 11. Again, similarly, a third working mark 1121 which is formed when an inner circumferential part or an outer circumferential part of the third straight tube part 1113 of the main shell 11 is pressed by a jig or the like, remains on the inner circumferential part or the outer circumferential part. After the main shell 11 is formed, as described with reference to FIG. 4(a), the fixed scroll 31 is fixed to the inner circumferential part of the first straight tube part 1111, the first frame 2 is fixed to the inner circumferential part of the second straight tube part 1112, and the drive mechanism portion 4 is fixed to the inner circumferential part of the third straight tube part 1113 .

[0024] In FIG. 5 and FIG. 6, three straight tube parts, two connection portions, and three working marks are provided, but the numbers thereof are not limited thereto. In addition, the first protruding portion 112 and the second protruding portion 115 are provided in FIG. 4, but the fixed scroll 31 and the first frame 2 may be fixed with equipment or a jig / tool without providing the first protruding portion 112 and the second protruding portion 115, and it is not intended to limit that the first protruding portion 112 and the second protruding portion 115 are necessarily provided.

[0025] As described above, using the outer diameter D2 of the second straight tube part 1112 as a reference, the main shell 11 is formed such that the outer diameter DI of the first straight tube part 1111 is enlarged and the outer diameter D3 of the third straight tube part 1113 is reduced. With this configuration, even if the ratio of the outer diameter DI of the first straight tube part 1111 and the outer diameter D3 of the third straight tube part 1113 of the main shell 11 exceeds the strain amount corresponding to the tensile strength of material forming the main shell 11, the strain amount actually caused when the outer diameter DI of the first straight tube part 1111 is enlarged using the outer diameter D2 of the second straight tube part 1112 as a reference, is smaller than the strain amount actually caused when the outer diameter DI of the first straight tube part 1111 is enlarged using the outer diameter D3 of the third straight tube part 1113 as a reference. Therefore, as per such comparison between the strain amounts, the configuration of the present embodiment reduces stress, and thus breakage of the main shell 11 can be suppressed.

[0026] Regarding an allowable range of stress caused when the diameter is enlarged or reduced as described above, a fourth straight tube part, which is not shown, may be formed so as to have an outer diameter D4 larger than the outer diameter DI of the first straight tube part 1111, or the fourth straight tube part, which is not shown, may be formed so as to have the outer diameter D4 smaller than the outer diameter D3 of the third straight tube part 1113. Further, in a similar method, an Nth straight tube part, which is not shown, may be formed so as to have an outer diameter DN (N is a natural number). In this case, although the outer diameter DK of the Kth straight tube part as a reference needs to satisfy D1<DK<DN, the value of K is preferably a value close to N / 2, from the viewpoint of the above-described stress.

[0027] As shown in FIG. 7, a welding mark 1122 is formed on an inner circumferential part or an outer circumferential part between the first connection portion 1117 and the second straight tube part 1112, whereby a working limit due to the breaking strength when either the first straight tube part 1111 or the second straight tube part 1112 is used as a reference for plastic working, is eliminated, so that the first straight tube part 1111 having a large diameter can be formed regardless of the breaking strength. In this case, although not shown in FIG. 7, the fixed scroll 31 and the first frame 2 may be fixed to the inner circumferential part of the first straight tube part 1111 having a large diameter, and the drive mechanism portion 4 may be fixed to the inner circumferential part of the second straight tube part 1112.

[0028] On the other hand, in the case where the first straight tube part 1111 and the third straight tube part 1113 are worked from the inner circumference side or the outer circumference side without deforming the second straight tube part 1112, the main shell 11 extends further to the U side / L side. Thus, when a thickness tl of the first straight tube part 1111, a thickness t2 of the second straight tube part 1112, and a thickness t3 of the third straight tube part 1113 are compared, tl<t3<t2 is satisfied and tl<t2 and t3<t2 are satisfied, in FIG. 8. In addition, the thickness of the first connection portion 1117 gradually decreases from the second straight tube part 1112 toward the first straight tube part 1111 such that the thickness at one end on the second straight tube part 1112 side is t2 and the thickness at the other end on the first straight tube part 1111 side is tl. The thickness of the second connection portion 1118 gradually decreases from the second straight tube part 1112 toward the third straight tube part 1113 such that the thickness at one end on the second straight tube part 1112 side is t2 and the thickness at the other end on the third straight tube part 1113 side, is t3.

[0029] Of the thickness tl of the first straight tube part 1111 and the thickness t3 of the third straight tube part 1113, a thickness for which an absolute value ( |tl—12| or |t3—t2|) of a difference from the thickness t2 of the second straight tube part 1112 is greater (in FIG. 8, the thickness tl for a greater absolute value |tl—t2| of a difference from the thickness t2), is smaller than a thickness for which an absolute value (|tl—t2| or |t3—t2|) of a difference from the thickness t2 of the second straight tube part 1112 is smaller (in FIG. 8, the thickness t3 for a smaller absolute value |t3—t2| of a difference from the thickness t2) (i.e., tl<t3). However, t3<tl<t2 is allowable, unlike the case in FIG. 8.

[0030] With this configuration, tl<t2 and t3<t2 are satisfied. Thus, the strain amount (i.e., stress) caused when, using the outer diameter D2 of the second straight tube part 1112 as a reference, the outer diameter DI of the first straight tube part 1111 is enlarged and the outer diameter D3 of the third straight tube part 1113 is reduced, can be made smaller than the strain amount caused when, using the outer diameter D3 of the third straight tube part 1113 as a reference, the outer diameter DI of the first straight tube part 1111 is enlarged.

[0031] In addition, the weight of the main shell 11 can be reduced as compared to a case where the main shell 11 having a cylindrical shape with a uniform thickness is provided, and the parts corresponding to the inner diameter of the second straight tube part 1112 and the inner diameter of the first straight tube part 1111 are worked to make the inner diameter of the second straight tube part 1112 and the inner diameter of the first straight tube part 1111 larger than the inner diameter of the third straight tube part 1113.

[0032] <Configuration of first frame 2> The first frame 2 is made of metal such as cast iron, and is a hollow frame having a hollow therein as shown in FIG. 9. The first frame 2 is provided inside the shell 1. The first frame 2 includes the body portion 21, a main bearing portion 22, and an oil return pipe 23. The body portion 21 is fixed to the inner wall surface on the U side of the main shell 11, and has, at the center, a storage space 211 formed along the longitudinal direction of the shell 1. The storage space 211 opens on the U side and is formed in a stepped shape so that the space is narrowed toward the L side .

[0033] The body portion 21 has, on the U side, an annular flat surface 212 formed so as to surround the storage space 211. On the flat surface 212, a ring-shaped thrust plate 24 made of a steel-plate material such as valve steel is provided. Therefore, in the present embodiment, the thrust plate 24 acts as a thrust bearing. Since the thrust plate 24 acts as a thrust bearing, a rotation stopper for suppressing rotation is needed. Although not shown here, for example, such a structure that the flat surface 212 of the first frame 2 is provided with a projection thinner than the thickness of the thrust plate 24 to suppress rotation of the thrust plate 24, or such a structure that the first frame 2 has a groove, the thrust plate 24 has a projection, and both components are fitted with each other, may be adopted.

[0034] A suction port 213 is formed on the outer end side of the flat surface 212 where the thrust plate 24 does not overlap. The suction port 213 is a space penetrating the body portion 21 in the up-down direction, i.e., between the upper shell 12 side and the lower shell 13 side. In FIG. 9, a case of providing two suction ports 213 and two oil return pipes 23 is shown, but the numbers thereof are not limited thereto. In addition, the suction ports 213 are shown as through holes, but they may be formed as cutouts with the outer wall partially removed.

[0035] The first frame 2 has the projection 216 protruding in the radial direction from the outer circumference part of the body portion 21, and the end on the lower shell 13 side of the projection 216 has C chamfered or R chamfered portions 2161, so that the projection width is gradually expanded from the end. The projection 216 is fitted with the groove 118 (see FIG. 3) formed on the main shell 11, thereby determining the phase of the first frame 2. As described above, the body portion 21 of the first frame 2 is brought into contact with the second positioning surface 116 (see FIG. 3) formed on the main shell 11, thereby determining the axial-direction position of the first frame 2.

[0036] Further, in this state, the first frame 2 is fixed to the second inner wall surface 114 or the third inner wall surface 117 of the main shell 11 by press fit or shrink fit, thereby determining the center position. If a retention force is insufficient, arc spot welding or the like may be further performed. Thus, the first frame 2 can be retained in the main shell 11 in a state in which the center position, the axial-direction height position, and the phase are determined.

[0037] The first frame 2 has an Oldham storage portion 214 at a stepped part on the L side relative to the flat surface 212. At the Oldham storage portion 214, a first Oldham groove 215 is formed. A part of the first Oldham groove 215 on the outer end side is formed such that the inner end side of the flat surface 212 is cut out. Thus, when the first frame 2 is seen from the U side, the first Oldham groove 215 partially overlaps the thrust plate 24. A pair of the first Oldham grooves 215 are formed so as to be opposed to each other .

[0038] With this configuration, the first frame 2 has the Oldham storage portion 214 which serves as a space for both storage and movement of an Oldham ring 33 described later and which is formed on a surface opposed to a first wrap 312 of the fixed scroll 31, and an orbiting scroll 32 is retained slidably via the Oldham ring 33, thereby determining the phase in the rotation direction of the orbiting scroll 32.

[0039] The main bearing portion 22 is formed contiguously on the L side of the body portion 21 and has a shaft hole 221 therein. The shaft hole 221 penetrates the main bearing portion 22 in the up-down direction, and the U side thereof communicates with the storage space 211. The oil return pipe 23 is a pipe for returning lubricant oil stored in the storage space 211 to an oil reservoir provided inside the lower shell 13, and is inserted and fixed into an oil discharge hole formed so as to penetrate the first frame 2 between the inner and outer sides.

[0040] The lubricant oil is refrigerant oil containing ester-based synthetic oil, for example. The lubricant oil is stored at the lower part of the shell 1, i.e., in the lower shell 13 (see FIG. 1 and FIG. 2) . The lubricant oil is sucked by an oil pump 52 described later and passes through an oil passage 63 in the crankshaft 6, to reduce wear between mechanically contacting members of the compression mechanism portion 3 and the like, adjust the temperatures of sliding parts, and improve sealing property. Preferably, the lubricant oil is high in lubrication property, electric insulation property, stability, refrigerant solubility, low-temperature fluidity, and the like, and has an appropriate viscosity.

[0041] <Configuration of compression mechanism portion 3> The compression mechanism portion 3 as shown in FIG. 2 is a compression mechanism for compressing the refrigerant. The compression mechanism portion 3 is a scroll compression mechanism including the fixed scroll 31 and the orbiting scroll 32. The fixed scroll 31 is made of metal such as cast iron, and includes the first base plate 311 and the first wrap 312 as shown in FIG. 10. The first base plate 311 has a disk shape, and has a discharge port 313 (see FIG. 2) penetrating in the up-down direction at the center. The first wrap 312 protrudes from the surface on the L side of the first base plate 311 so as to form a spiral wall, and the tip thereof protrudes toward the L side.

[0042] As shown in FIG. 2 and FIG. 5, the fixed scroll 31 has the projection 314 protruding toward the lower shell 13 side (L side) from the surface of the first base plate 311 on the side where the first wrap 312 is formed, and the end on the lower shell 13 side of the projection 314 has C chamfered or R chamfered portions 3141, so that the projection width is gradually expanded from the end. The projection 314 is fitted with the groove 118 (see FIG. 3) formed on the main shell 11, thereby determining the phase of the fixed scroll 31.

[0043] In addition, as shown in FIG. 3, the surface of the first base plate 311 of the fixed scroll 31 on the side where the first wrap 312 is formed is brought into contact with the first positioning surface 113 formed on the main shell 11, thereby determining the axial-direction position of the fixed scroll 31. Further, in this state, a side surface 3111 of the first base plate 311 is fixed to the first inner wall surface 111 of the main shell 11 by shrink fit, thereby determining the center position. Thus, the fixed scroll 31 can be retained in the main shell 11 in a state in which the center position, the axial-direction height position, and the phase are determined. In addition, a function of separating a high pressure and a low pressure inside the shell 1 is imparted to the fixed scroll 31. Therefore, it is necessary to apply a pressure to the side surface 3111 of the first base plate 311 of the fixed scroll 31 and the first inner wall surface 111 of the main shell 11 over the entire circumference by shrink fit, so that the refrigerant will not leak. Accordingly, the shrink-fit position is the first inner wall surface 111 where the groove 118 is not formed.

[0044] The orbiting scroll 32 is made of metal such as aluminum, and includes a second base plate 321, a second wrap 322, a tube-shaped portion 323, and a second Oldham groove 324 as shown in FIG. 11. The second base plate 321 has a disk shape having one surface on which the second wrap 322 is formed, another surface whose outer circumferential area serves, at least partially, as a sliding surface 3211, and a side surface 3212 located at the radially outermost side and connecting the one surface and the other surface. The sliding surface 3211 is slidable against the thrust plate 24, and is supported (borne) by the first frame 2. The second wrap 322 protrudes from the one surface of the second base plate 321 so as to form a spiral wall, and the tip thereof protrudes toward the U side.

[0045] At the tips of the first wrap 312 of the fixed scroll 31 and the second wrap 322 of the orbiting scroll 32, seal members for suppressing leakage of the refrigerant are provided. The tube-shaped portion 323 is a cylindrical boss protruding from substantially the center of the other surface of the second base plate 321 toward the L side. On the inner circumferential surface of the tube-shaped portion 323, a swing bearing (so-called journal bearing) for rotatably supporting a slider 71 described later is provided such that the center axis of the bearing is parallel with the center axis of the crankshaft 6. The second Oldham groove 324 is a long round-shaped groove formed at the other surface of the second base plate 321. A pair of the second Oldham grooves 324 are provided so as to be opposed to each other. A line connecting the pair of second Oldham grooves 324 is set to be perpendicular to a line connecting the pair of first Oldham grooves 215 shown in FIG. 9.

[0046] The Oldham ring 33 is provided in the Oldham storage portion 214 of the first frame 2 (see FIG. 9). As shown in FIG. 12, the Oldham ring 33 includes a ring portion 331, a first key portion 332, and a second key portion 333. The ring portion 331 has a ring shape. A pair of the first key portions 332 are formed so as to be opposed to each other on the surface on the L side of the ring portion 331, and are stored in the pair of first Oldham grooves 215 of the first frame 2. A pair of the second key portions 333 are formed so as to be opposed to each other on the surface on the U side of the ring portion 331, and are stored in the pair of second Oldham grooves 324 of the orbiting scroll 32 (see FIG. 11).

[0047] When the orbiting scroll 32 revolves and orbits along with rotation of the crankshaft 6, the first key portions 332 slide in the first Oldham grooves 215 and the second key portions 333 slide in the second Oldham grooves 324, whereby the Oldham ring 33 prevents the orbiting scroll 32 from rotating. The first wrap 312 of the fixed scroll 31 and the second wrap 322 of the orbiting scroll 32 are meshed with each other, whereby a compression chamber 34 is formed.

[0048] The volume of the compression chamber 34 is reduced from the outer side toward the inner side in the radial direction, and thus the refrigerant is gradually compressed while moving to the center side after being sucked from the outer side of the wrap.

[0049] As shown in FIG. 2, the compression chamber 34 communicates with the discharge port 313, at a center part of the fixed scroll 31. On a surface on the one end side U of the fixed scroll 31, a muffler 35 having a discharge hole 351 is provided, and a discharge valve 36 which opens / closes the discharge hole 351 in a predetermined case to prevent reverse flow of the refrigerant is provided.

[0050] Examples of the refrigerant are halogenated hydrocarbon having a double bond of carbon in the composition, halogenated hydrocarbon not having a double bond of carbon, hydrocarbon, and a mixture containing these. As the halogenated hydrocarbon having a double bond of carbon, there are an HEC refrigerant and a chlorofluorocarbon-based low-GWP refrigerant of which the ozone depletion potential is zero, and an example thereof is tetrafluoropropene such as HFO1234yf, HFO1234ze, or HFO1243zf, represented by the chemical formula C3H2F4. Examples of the halogenated hydrocarbon not having a double bond of carbon are a refrigerant of R32 (difluoromethane) represented by CH2F2, and a refrigerant with R41, etc., mixed therein. Examples of the hydrocarbon are propane and propylene which are natural refrigerants. Examples of the mixture are mixed refrigerants obtained by mixing R32, R41, etc. in HFO1234yf, HFO1234ze, HFO1243zf, etc.

[0051] <Configuration of drive mechanism portion 4> As shown in FIG. 2, the drive mechanism portion 4 is provided on the L side relative to the first frame 2 inside the shell 1. The drive mechanism portion 4 includes a stator 41 and a rotor 42. The stator 41 is formed by winding a wire, with an insulating layer interposed, around a core composed of a plurality of stacked electromagnetic steel sheets, and is formed in a ring shape. The stator 41 is fixed and supported inside the main shell 11 by shrink fit or the like. The rotor 42 is formed such that permanent magnets are provided inside a core composed of a plurality of stacked electromagnetic steel sheets, and is formed in a cylindrical shape having a through hole penetrating in the up-down direction at the center. The rotor 42 is provided in the internal space of the stator 41.

[0052] <Configuration of second frame 5> The second frame 5 is a frame made of metal such as cast iron, and is provided on the L side of the drive mechanism portion 4 inside the shell 1 as shown in FIG. 2. The second frame 5 is fixed and supported on the inner circumferential surface on the L side of the main shell 11 by shrink fit, welding, or the like. The second frame 5 includes a sub bearing portion 51 and the oil pump 52. The sub bearing portion 51 is a ball bearing provided on the upper side at a center part of the second frame 5, and has a hole penetrating in the up-down direction at the center. The oil pump 52 is provided on the lower side at a center part of the second frame 5, and is placed so as to be at least partially immersed in the lubricant oil stored in the oil reservoir of the shell 1. In the present embodiment, a ball bearing is shown as the sub bearing portion 51 as an example. However, this may be a journal bearing, for example.

[0053] <Configuration of crankshaft 6> The crankshaft 6 is a long rod-shaped member made of metal, and includes the main shaft portion 61, an eccentric shaft portion 62, and the oil passage 63 as shown in FIG. 13. The crankshaft 6 is provided inside the shell 1 as shown in FIG. 2. The main shaft portion 61 is a shaft forming a major part of the crankshaft 6, and is placed such that the center axis thereof coincides with the center axis of the main shell 11. The rotor 42 is fixed in contact with the outer surface of the main shaft portion 61. The eccentric shaft portion 62 is provided on the U side of the main shaft portion 61 such that the center axis thereof is eccentric relative to the center axis of the main shaft portion 61. The oil passage 63 is provided so as to penetrate in the up-down direction inside the main shaft portion 61 and the eccentric shaft portion 62.

[0054] Regarding the crankshaft 6, the U side of the main shaft portion 61 is inserted into the main bearing portion 22 of the first frame 2, and the L side is inserted and fixed into the sub bearing portion 51 of the second frame 5. Thus, the eccentric shaft portion 62 is placed in the tube of the tube-shaped portion 323, and the outer circumferential surface of the rotor 42 and the inner circumferential surface of the stator 41 are located with a predetermined gap therebetween. A first balancer 64 is provided on the U side of the main shaft portion 61, and a second balancer 65 is provided on the L side, so as to cancel out imbalance due to swing of the orbiting scroll 32.

[0055] <Configuration of bush 7> The bush 7 is made of metal such as iron, and is a connection member connecting the orbiting scroll 32 and the crankshaft 6 as shown in FIG. 2. In the present embodiment, as shown in FIG. 14, the bush 7 is composed of two components, and includes a slider 71 and a balance weight 72. The slider 71 is a tube-shaped member having a flange, and is fitted with each of the eccentric shaft portion 62 (see FIG. 2) and the tube-shaped portion 323 (see FIG. 11). The balance weight 72 is a doughnut-shaped member having a weight portion 721 whose shape as seen from the U side is substantially a C shape. The balance weight 72 is provided eccentrically relative to the rotation center so as to cancel out the centrifugal force of the orbiting scroll 32. The balance weight 72 is, for example, fitted with the flange of the slider 71 by shrink fit or the like. The bush 7 may be formed as one component by being cut to have the slider 71 and the balance weight 72 integrally through mechanical working, for example.

[0056] Configuration of power supply portion 8> The power supply portion 8 is a power supply member for supplying power to the scroll compressor, and is formed on the outer circumferential surface of the main shell 11 of the shell 1 as shown in FIG. 1 and FIG. 2. The power supply portion 8 includes a cover 81, a power supply terminal 82, and a wire 83. The cover 81 is a bottomed cover member having an opening. The power supply terminal 82 is a metal member, with one side provided inside the cover 81 and another side provided inside the shell 1. One side of the wire 83 is connected to the power supply terminal 82 and another side is connected to the stator 41.

[0057] <Method for adjusting wrap tip clearance of scroll compressor> Next, a method for adjusting the clearance between each wrap tip and each base plate of the fixed scroll 31 and the orbiting scroll 32 (wrap tip clearance) will be described with reference to FIG. 15. FIG. 15 is obtained by adding dimensions to FIG. 4(a) . The dimensions of the respective parts are set as follows, and then a wrap tip clearance Q can be represented by the following expression. L: the distance between the first positioning surface 113 and the second positioning surface 116 M: the distance between the first positioning surface 113 and the tip of the first wrap 312 N: the thickness of the second base plate 321 of the orbiting scroll 32 T: the thickness of the thrust plate 24 P: the distance between the second positioning surface 116 and the flat surface 212 Q: wrap tip clearance L=M+Q+N+T+P Thus, Q=L-M-N-T-P is obtained. Here, if the dimensions of the respective parts are known, it is possible to obtain a desired wrap tip clearance Q by adjusting the thickness T of the thrust plate 24 for which most types of and a largest number of products can be produced. Through such adjustment, the refrigerant is prevented from passing through the clearance between each wrap tip and each base plate and leaking into an adjacent compression space, and thus loss of the compressor can be reduced.

[0058] Although the disclosure is described above in terms of an exemplary embodiment, it should be understood that the various features, aspects, and functionality described in the embodiment are not limited in their applicability to the particular embodiment with which they are described, but instead can be applied alone or in various combinations to the embodiment of the disclosure. It is therefore understood that numerous modifications which have not been exemplified can be devised without departing from the scope of the present disclosure. For example, at least one of the constituent components may be modified, added, or eliminated. DESCRIPTION OF THE REFERENCE CHARACTERS

[0059] 1 shell 11 main shell 111 first inner wall surface 1111 first straight tube part 1112 second straight tube part 1113 third straight tube part 1117 first connection portion 1118 second connection portion 1119 first working mark 1120 second working mark 1121 third working mark 112 first protruding portion 113 first positioning surface 1131 recess 114 second inner wall surface 115 second protruding portion 116 second positioning surface 1161 recess 117 third inner wall surface 118 groove 1181 chamfered portion 12 upper shell 13 lower shell 14 suction pipe 15 discharge pipe 16 fixation base 2 first frame 21 body portion 211 storage space 212 flat surface 213 suction port 214 Oldham storage portion 215 first Oldham groove 216 projection 2161 chamfered portion 22 main bearing portion 221 shaft hole 23 oil return pipe 24 thrust plate 3 compression mechanism portion 31 fixed scroll 311 first base plate 3111 side surface 312 first wrap 314 projection 3141 chamfered portion 32 orbiting scroll 321 second base plate 322 second wrap 3211 sliding surface 3212 side surface 323 tube-shaped portion 324 second Oldham groove 33 Oldham ring 331 ring portion 332 first key portion 333 second key portion 34 compression chamber 35 muffler 351 discharge hole 36 discharge valve 4 drive mechanism portion 41 stator 42 rotor 5 second frame 51 sub bearing portion 52 oil pump 6 crankshaft 62 eccentric shaft portion 63 oil passage 7 bush 71 slider 5 72 balance weight 721 weight portion 8 power supply portion 81 cover 82 power supply terminal io

Claims

1. A scroll compressor comprising:a compression mechanism portion (3) having a fixed scroll (31) and an orbiting scroll (32);a frame (2) slidably retaining the orbiting scroll (32) ;a drive mechanism portion (4) which slides the orbiting scroll (32); anda tube-shaped main shell (1) storing therein the compression mechanism portion (3), the frame (2), and the drive mechanism portion (4), whereinthe main shell (1) includes a first straight tube part (1111) extending along a center axis, a second straight tube part (1112) extending along the center axis and having a smaller outer diameter than the first straight tube part (1111), and a third straight tube part (1113) extending along the center axis and having a smaller outer diameter than the second straight tube part (1112), andthe fixed scroll (31) is fixed in the first straight tube part (1111), the frame (2) is fixed in the second straight tube part (1112), and the drive mechanism portion (4) is fixed in the third straight tube part (1113) .

2. The scroll compressor according to claim 1, wherein a thickness of the first straight tube part (1111) is smallerthan a thickness of the second straight tube part (1112) .

3. The scroll compressor according to claim 1, wherein of a thickness of the first straight tube part (1111) and a thickness of the third straight tube part (1113), a thickness for which an absolute value of a difference from a thickness of the second straight tube part (1112) is greater, is smaller than a thickness for which an absolute value of a difference from a thickness of the second straight tube part (1112) is smaller.

4. The scroll compressor according to claim 1, wherein a first connection portion (1117) connecting the first straight tube part (1111) and the second straight tube part (1112), and a second connection portion (1118) connecting the second straight tube part (1112) and the third straight tube part (1113), are provided.

5. The scroll compressor according to claim 1, wherein a first protruding portion (112) which protrudes from an inner wall surface of the first straight tube part (1111) and determines a position of the fixed scroll (31), and a second protruding portion (115) which protrudes from an inner wall surface of the second straight tube part (1112) and determines a position of the frame (2), are provided.

6. The scroll compressor according to claim 1, wherein the first straight tube part (1111), the second straight tube part (1112), and the third straight tube part (1113) each have a working mark (1119, 1110, 1121) on an inner circumferential part or an outer circumferential part thereof .

7. The scroll compressor according to claim 1, comprising:a first connection portion (1117) connecting the first straight tube part (1111) and the second straight tube part (1112),and whereina welding mark (1122) is formed on an inner circumferential part or an outer circumferential part between the first connection portion (1117) and the second straight tube part (1112) .

8. A method for manufacturing a scroll compressor including a compression mechanism portion (3) having a fixed scroll (31) and an orbiting scroll (32), a frame (2) slidably retaining the orbiting scroll (32), a drive mechanism portion (4) which slides the orbiting scroll (32), and a tube-shaped main shell (1) storing therein the compression mechanism portion (3), the frame (2), and the drive mechanism portion(4), the method comprising:in the main shell (1), using a second straight tube part (1112) extending along a center axis as a reference,a step of forming a first straight tube part (1111)5 extending along the center axis so as to have a larger outer diameter than the second straight tube part (1112);a step of forming a third straight tube part (1113) extending along the center axis so as to have a smaller outer diameter than the second straight tube part (1112); and10 a step of fixing the fixed scroll (31) to an innercircumferential part of the first straight tube part (1111), fixing the frame (2) to an inner circumferential part of the second straight tube part (1112), and fixing the drivemechanism portion (4) to an inner circumferential part of the 15 third straight tube part (1113) .

Images