Scroll compressor and manufacturing method thereof

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 drive mechanism unit (4) for sliding the orbiting scroll (32) is composed of a first straight tube section (1111) extending along the central axis, a second straight tube section (1112) having a smaller outer diameter than the first straight tube section (1111), and a third straight tube section (1113) having a smaller outer diameter than the second straight tube section (1112). Due to the outer diameter (D3) of the third straight tube section being reduced, the main shell (11) can be kept from breaking even when the ratio between the outer diameter (D1) of the first straight tube section and the outer diameter (D3) of the third straight tube section of the main shell (11) exceeds a strain amount equivalent to the tensile strength of the material forming the main shell (11).

Description

[Technical Field]

[0001] The present application relates to a scroll compressor and a method for manufacturing the same. [Background technology]

[0002] A scroll compressor is known that is configured with a stator fixed to the center inside the shell, a main frame fixed to the upper part inside the shell, a subframe fixed to the lower part inside the shell, a crankshaft supported by bearings fixed to the main frame and the subframe, a rotor fixed to the crankshaft, an orbiting scroll attached to an eccentric part at the tip of the crankshaft, and a fixed scroll disposed opposite the orbiting scroll and fixed to the shell (see, for example, Patent Document 1). The crankshaft is rotated by the power of the stator and rotor, causing the orbiting scroll to oscillate relative to the fixed scroll, and refrigerant is compressed in a compression chamber formed by the orbiting scroll and the fixed scroll. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2018 / 078787 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the scroll compressor described in Patent Document 1, when the straight pipe sections of the main shell are expanded in the radial direction, such as the first and second straight pipe sections of the main shell, stress inside the main shell increases, which poses a problem that the increased stress may reach the tensile strength of the material that constitutes the main shell, causing the main shell to break.

[0005] The present application has been made to solve the above-mentioned problems, and has an object to provide a scroll compressor having a structure that can suppress breakage of the main shell. [Means for solving the problem]

[0006] The scroll compressor disclosed in the present application comprises a compression mechanism having a fixed scroll and an orbiting scroll, a frame that slidably holds the orbiting scroll, a drive mechanism that slides the orbiting scroll, and a cylindrical main shell that houses the compression mechanism, the frame, and the drive mechanism, wherein the main shell has a first straight pipe section extending along the central axis, a second straight pipe section that extends along the central axis and has a smaller outer diameter than the first straight pipe section, and a third straight pipe section that extends along the central axis and has a smaller outer diameter than the second straight pipe section, and is characterized in that the fixed scroll is fixed within the first straight pipe section, the frame is fixed within the second straight pipe section, and the drive mechanism is fixed within the third straight pipe section. [Effects of the Invention]

[0007] According to the scroll compressor disclosed in the present application, by increasing the diameter of the first straight pipe section and decreasing the diameter of the third straight pipe section based on the second straight pipe section, it is possible to prevent the main shell from breaking even if the ratio of the outer diameter of the first straight pipe section of the main shell to the outer diameter of the third straight pipe section exceeds the amount of strain corresponding to the tensile strength of the material constituting the main shell. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a perspective view of a scroll compressor according to a first embodiment. [Figure 2] 1 is a cross-sectional view of a scroll compressor according to a first embodiment. [Figure 3] FIG. 2 is a perspective view of a main part of a main shell according to the first embodiment. [Figure 4] FIG. 3 is an enlarged view of the area surrounded by the dashed line in FIG. 2. [Figure 5] FIG. 3 is an enlarged cross-sectional view of a main shell according to the first embodiment. [Figure 6]FIG. 3 is an enlarged cross-sectional view of a main shell according to the first embodiment. [Figure 7] FIG. 3 is an enlarged cross-sectional view of a main shell according to the first embodiment. [Figure 8] FIG. 3 is an enlarged cross-sectional view of a main shell according to the first embodiment. [Figure 9] FIG. 2 is a perspective view of a main part of a first frame according to the first embodiment. [Figure 10] FIG. 2 is a perspective view of a main part of the fixed scroll according to the first embodiment. [Figure 11] 1 is a perspective view of a main part of an orbiting scroll according to a first embodiment. [Figure 12] FIG. 1 is a perspective view of an Oldham ring according to a first embodiment. [Figure 13] FIG. 1 is a perspective view of a crankshaft according to a first embodiment. [Figure 14] FIG. 2 is a perspective view of a bush according to the first embodiment. [Figure 15] 5 is a diagram for explaining the dimensional relationship of the area enclosed by the dashed line in the main shell shown in FIG. 4. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, preferred embodiments of a scroll compressor according to the present invention will be described with reference to the drawings. The same components and parts will be designated by the same reference numerals, and detailed descriptions thereof will be omitted. Similarly, in the following embodiments, redundant descriptions of components designated by the same reference numerals will be omitted.

[0010] Embodiment 1 Fig. 1 is a perspective view of a scroll compressor, and Fig. 2 is a schematic vertical cross-sectional view of the scroll compressor according to the first embodiment. The compressor in Fig. 1 is a so-called vertical scroll compressor that is used with a main shaft portion 61 (center axis) of a crankshaft approximately perpendicular to the ground. Hereinafter, the vertical scroll compressor shown in Fig. 1 will be referred to as a scroll compressor in the following description.

[0011] The scroll compressor includes a shell 1, a first frame 2, a compression mechanism 3, a drive mechanism 4, a second frame 5, a crankshaft 6, a bushing 7, and a power supply unit 8. In the following description, the first frame 2 is used as a reference, and the side where the compression mechanism 3 is provided (upper side) is designated as the U-side, and the side where the drive mechanism 4 is provided (lower side) is designated as the L-side. Note that although the first frame 2, compression mechanism 3, and crankshaft 6 are not directly shown in FIG. 2, the first digit of the reference numeral attached to each component indicates the component of the first frame 2, compression mechanism 3, or crankshaft 6.

[0012] The shell 1 is a metal housing with both ends closed, and includes a main shell 11, an upper shell 12, and a lower shell 13. The main shell 11 is cylindrical, and an intake pipe 14 is connected to its side wall by welding or the like.

[0013] 2, suction pipe 14 is a pipe that introduces refrigerant into shell 1 and communicates with the interior of main shell 11. Upper shell 12 is roughly hemispherical, and a portion of its side wall is connected to the upper end of main shell 11 by welding or the like, covering the upper opening of main shell 11. Discharge pipe 15 is connected to the top of upper shell 12 by welding or the like. Discharge pipe 15 is a pipe that discharges refrigerant to the outside of shell 1 and communicates with the internal space of main shell 11.

[0014] The lower shell 13 is substantially hemispherical, and a portion of its side wall is connected to the lower end of the main shell 11 by welding or the like, covering the lower opening of the main shell 11. The shell 13 is supported by a fixing base 16 having a plurality of screw holes. The fixing base 16 has a plurality of screw holes formed therein, and by threading screws into these screw holes, the scroll compressor can be fixed to another member such as the housing of the outdoor unit.

[0015] Each component will be described in detail below. <Configuration of main shell 11> 1 and 2, the main shell 11 is shown as a cylinder for simplification, and variations in the inner diameter and outer shape of the main shell are omitted. However, the outer structure of the main shell 11 has the following characteristics.

[0016] 3, the main shell 11 has a first protruding portion 112 having a second inner wall surface 114 protruding radially from the first inner wall surface 111, a first positioning surface 113 at an end surface of the first protruding portion 112 facing the upper shell 12, which contacts a first base plate 311 (see FIG. 10 described later) of the fixed scroll 31 shown in FIG. 2 to determine the axial position of the fixed scroll 31, a second protruding portion 115 having a third inner wall surface 117 protruding further radially from the first protruding portion 112, and a second positioning surface 116 at an end surface of the second protruding portion 115 facing the upper shell 12, which contacts a main body portion 21 of the first frame 2 to determine the axial position of the first frame 2. In other words, the main shell 11 has a stepped portion whose inner diameter decreases toward the L side shown in FIG. 2.

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

[0018] Furthermore, the first protrusion 112 is formed with a groove 118 that fits with a protrusion 314 (see FIG. 10) of the fixed scroll 31, which will be described later, and a protrusion 216 (see FIG. 9), which will be described later, of the first frame 2, to determine the phase of both components. A C-chamfer or R-chamfer 1181 is formed at the tip of the groove 118 on the upper shell 12 side, and the groove width gradually narrows from the tip. This allows the chamfer 118 to act as a guide, guiding the protrusion 216 of the first frame 2 and the protrusion 314 of the fixed scroll 31, facilitating assembly and improving the assembly performance of the compressor.

[0019] Fig. 4(a) is an enlarged view of the portion surrounded by the dashed line in Fig. 2, and Figs. 4(b) and 4(c) are enlarged views of the circled areas A and B in Fig. 4(a), respectively. As shown in Figs. 4(b) and 4(c), recesses 1131 and 1161 are provided at the corner where the first positioning surface 113 and the first inner wall surface 111 intersect, and at the corner where the second positioning surface 116 and the second inner wall surface 114 intersect, respectively. This allows the fixed scroll 31 and the first frame 2 to reliably contact each positioning surface.

[0020] In addition, when the main shell 11 is manufactured from a welded steel pipe, which is made by rolling or pressing a steel plate into a tubular shape and then welding the joints together to form a steel pipe, the groove 118 can be formed in a location other than the welded joint, so that the groove can be formed without compromising the reliability of the main shell 11.

[0021] Next, the structure of the wall surface of the main shell 11 will be described in more detail with reference to the cross sections shown in Figures 5 and 6. Figure 6 shows a cross section of the main shell 11 with the first frame 2, compression mechanism 3, and drive mechanism 4 attached to it in Figure 5. From the U-side of the main shell 11, it comprises a first straight pipe section 1111, a second straight pipe section 1112, and a third straight pipe section 1113, and is divided into a first connecting section 1117 connecting the first straight pipe section 1111 and the second straight pipe section 1112, and a second connecting section 1118 connecting the second straight pipe section 1112 and the third straight pipe section 1113. Because the main shell 11 has a cylindrical shape, the same cross-sectional configuration as shown in Figures 5 and 6 is also formed on the side opposite the central axis of the crankshaft.

[0022] The relationship between the outer diameter D1 of the first straight pipe portion 1111 of the main shell 11, the outer diameter D2 of the second straight pipe portion 1112 of the main shell 11, and the outer diameter D3 of the third straight pipe portion 1113 of the main shell 11 is D1 > D2 > D3. The first straight pipe portion 1111 of the main shell 11 is located at a position including the first inner wall surface 111 with which the main shell 11 and the fixed scroll 31 are fitted together. The second straight pipe portion 1112 of the main shell 11 is located at a position including the second inner wall surface 114 with which the main shell 11 and the body portion 21 of the first frame 2 are fitted together.

[0023] For example, the first straight pipe portion 1111, the second straight pipe portion 1112, the third straight pipe portion 1113, the first connecting portion 1117, and the second connecting portion 1118 of the main shell 11 are formed by press working or the like. That is, using the second straight pipe portion 1112 extending along the central axis of the crankshaft 6 as a reference, the first straight pipe portion 1111 extending along the central axis is formed so that its inner diameter is larger than that of the second straight pipe portion 1112, and the third straight pipe portion 1113 extending along the central axis is formed so that its inner diameter is smaller than that of the second straight pipe portion 1112. At this time, a first processing mark 1119 is left on the inner diameter or outer diameter of the first straight pipe portion 1111 of the main shell 11, caused by the inner diameter or outer diameter being pressed with a jig or the like. Similarly, second machining marks 1120 remain on the inner diameter or outer diameter of the second straight pipe section 1112 of the main shell 11. Furthermore, similarly, third machining marks 1121 remain on the inner diameter or outer diameter of the third straight pipe section 1113 of the main shell 11, caused by the inner diameter or outer diameter being held down with a jig or the like. After the main shell 11 is formed, as described in FIG. 4(a), the fixed scroll 31 is fixed to the inner diameter of the first straight pipe section 1111, the first frame 2 is fixed to the inner diameter of the second straight pipe section 1112, and the drive mechanism section 4 is fixed to the inner diameter of the third straight pipe section 1113.

[0024] 5 and 6, three straight pipe portions, two connecting portions, and three processing marks are provided, but the numbers are not limited to these. Also, as shown in Fig. 4, the first protruding portion 112 and the second protruding portion 115 are provided, but it is also possible to fix the fixed scroll 31 and the first frame 2 with equipment or jigs without providing these, and the provision of the first protruding portion 112 and the second protruding portion 115 is not a requirement.

[0025] As described above, the shape of the main shell 11 is such that the outer diameter D1 of the first straight pipe portion 1111 is enlarged and the outer diameter D3 of the third straight pipe portion 1113 is reduced with reference to the outer diameter D2 of the second straight pipe portion 1112. With this configuration, even if the ratio of the outer diameter D1 of the first straight pipe portion 1111 to the outer diameter D3 of the third straight pipe portion 1113 of the main shell 11 exceeds the amount of strain corresponding to the tensile strength of the material constituting the main shell 11, the actually generated strain is smaller than the amount of strain when the outer diameter D1 of the first straight pipe portion 1111 is enlarged with reference to the outer diameter D3 of the third straight pipe portion 1113, and is smaller than the amount of strain when the outer diameter D1 of the first straight pipe portion 1111 is enlarged with reference to the outer diameter D2 of the second straight pipe portion 1112. Therefore, as shown by this comparison of the amounts of strain, the stress is reduced by the structure of the present embodiment, so that breakage of the main shell 11 can be suppressed.

[0026] In addition, within the allowable range of stress generated during the above-described enlargement or reduction, the outer diameter D1 of the first straight pipe portion 1111 may be further enlarged to form an outer diameter D4 of a fourth straight pipe portion (not shown), or the outer diameter D3 of the third straight pipe portion 1113 may be further reduced to form an outer diameter D4 of a fourth straight pipe portion (not shown). Then, in the same manner, an outer diameter DN (N is a natural number) of an Nth straight pipe portion (not shown) may be formed. In this case, the outer diameter DK of the reference Kth straight pipe portion only needs to satisfy D1 < DK < DN, but the value of K is preferably a value close to N / 2 from the viewpoint of the above-described stress.

[0027] Also, as shown in FIG. 7, by having a welding mark 1122 on the inner diameter or the outer diameter between the first connecting portion 1117 and the second straight pipe portion 1112, the processing limit due to the breaking strength during plastic processing with reference to either the inside of the first straight pipe portion 1111 or the second straight pipe portion 1112 is eliminated, and the first straight pipe portion 1111 having a larger diameter can be provided 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 diameter of the first straight pipe portion 1111 having such a large diameter, and the drive mechanism portion 4 may be fixed to the inner diameter of the second straight pipe portion 1112.

[0028] On the one hand, when the first straight pipe portion 1111 and the third straight pipe portion 1113 are processed from the inner diameter side or the outer diameter side without deforming the second straight pipe portion 1112, the main shell 11 extends to the U side and the L side. Therefore, when comparing the wall thickness t1 of the first straight pipe portion 1111, the wall thickness t2 of the second straight pipe portion 1112, and the wall thickness t3 of the third straight pipe portion 1113, in FIG. 8, t1 < t3 < t2, and t1 < t2, t3 < t2. Also, the wall thickness of the first connecting portion 1117 gradually decreases from the second straight pipe portion 1112 toward the first straight pipe portion 1111 such that the wall thickness at one end on the second straight pipe portion 1112 side is t2 and the wall thickness at the other end on the first straight pipe portion 1111 side is t1. And the wall thickness of the second connecting portion 1118 gradually decreases from the second straight pipe portion 1112 toward the third straight pipe portion 1113 such that the wall thickness at one end on the second straight pipe portion 1112 side is t2 and the wall thickness at the other end on the third straight pipe portion 1113 side is t3.

[0029] Also, among the wall thickness t1 of the first straight pipe portion 1111 and the wall thickness t3 of the third straight pipe portion 1113, the wall thickness with the larger absolute value of the difference from the wall thickness t2 of the second straight pipe portion 1112 (|t1 - t2| and |t3 - t2|) (in FIG. 8, the wall thickness t1 with the larger absolute value of the difference from the wall thickness t2) is smaller than the wall thickness with the smaller absolute value of the difference from the wall thickness t2 of the second straight pipe portion 1112 (|t1 - t2| and |t3 - t2|) (in FIG. 8, the wall thickness t3 with the smaller absolute value of the difference from the wall thickness t2) (that is, t1 < t3). Note that, different from the case of FIG. 8, it may be t3 < t1 < t2.

[0030] With this configuration, since t1 < t2 and t3 < t2 can be achieved, when the outer diameter D1 of the first straight pipe portion 1111 is enlarged and the outer diameter D3 of the third straight pipe portion 1113 is reduced based on the outer diameter D2 of the second straight pipe portion 1112, the amount of strain (that is, stress) can be suppressed more than when the outer diameter D1 of the first straight pipe portion 1111 is enlarged based on the outer diameter D3 of the third straight pipe portion 1113.

[0031] In addition, by processing the portions corresponding to the inner diameter of the second straight pipe section 1112 and the inner diameter of the first straight pipe section 1111 from the state of a cylinder with a uniform wall thickness, the main shell 11 can be made lighter than if the inner diameter of the second straight pipe section 1112 and the inner diameter of the first straight pipe section 1111 were made larger than the inner diameter of the third straight pipe section 1113.

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

[0033] An annular flat surface 212 is formed on the U-side of the main body 21 so as to surround the housing space 211. A ring-shaped thrust plate 24 made of a steel plate material such as valve steel is disposed on the flat surface 212. Therefore, in this embodiment, the thrust plate 24 functions as a thrust bearing. Since the thrust plate 24 functions as a thrust bearing, a detent is required to suppress rotation. Although not shown here, for example, a protrusion thinner than the thickness of the thrust plate 24 may be provided on the flat surface 212 of the first frame 2 to suppress rotation of the thrust plate 24, or a groove may be formed in the first frame 2 and a protrusion may be formed on the thrust plate 24, and the two parts may be fitted together.

[0034] Furthermore, an intake port 213 is formed on the outer end side of the flat surface 212, not overlapping with the thrust plate 24. The intake port 213 is a space that penetrates the main body 21 in the vertical direction, i.e., from the upper shell 12 side to the lower shell 13 side. In Figure 9, there are two intake ports 213 and two oil return pipes 23, but the number is not limited to this. Furthermore, although the intake port 213 is a through hole, it may also be a notch shape with the outer wall removed.

[0035] The first frame 2 has a protrusion 216 that protrudes radially from the outer diameter of the main body 21, and a C-chamfer or R-chamfer 2161 is formed at the tip of the protrusion 216 on the lower shell 13 side, so that the protrusion width gradually widens from the tip. The phase of the first frame 2 is determined by fitting the protrusion 216 into a groove 118 (see FIG. 3) formed in the main shell 11. Also, as described above, the axial position of the first frame 2 is determined by abutting the main body 21 of the first frame 2 against the second positioning surface 116 (see FIG. 3) formed in the main shell 11.

[0036] Furthermore, in this state, the center position is determined by fixing the first frame 2 to the second inner wall surface 114 or the third inner wall surface 117 of the main shell 11 by press fitting or shrink fitting. If the holding force is insufficient, arc spot welding or the like may be further applied. As a result, the first frame 2 can be held in the main shell 11 with its center position, axial height position, and phase determined.

[0037] An Oldham receiving portion 214 is formed in a step portion on the L side of the flat surface 212 of the first frame 2. A first Oldham groove 215 is formed in the Oldham receiving portion 214. The first Oldham groove 215 is formed so that a portion of its outer end side is cut into the inner end side of the flat surface 212. Therefore, when the first frame 2 is viewed from the U side, a portion of the first Oldham groove 215 overlaps with the thrust plate 24. The first Oldham grooves 215 are formed so that a pair of them face each other.

[0038] With this configuration, the first frame 2 forms an Oldham accommodating section 214, which serves as a storage and operating space for the Oldham ring 33 described later, on the surface facing the first spiral body 312 of the fixed scroll 31, and determines the phase of the rotational direction of the orbiting scroll 32 while holding the orbiting scroll 32 slidably via the Oldham ring 33.

[0039] The main bearing portion 22 is formed contiguous with the L side of the main body portion 21, and has a shaft hole 221 formed therein. The shaft hole 221 penetrates the main bearing portion 22 in the up-and-down direction, and its U side is connected to the accommodation space 211. The oil return pipe 23 is a pipe for returning the lubricating oil accumulated in the accommodation space 211 to an oil reservoir inside the lower shell 13, and is inserted and fixed in an oil drain hole formed in the first frame 2 so as to penetrate the inside and outside of the first frame 2.

[0040] The lubricating oil is, for example, a refrigeration oil containing an ester-based synthetic oil. The lubricating oil is stored in the lower part of the shell 1, i.e., in the lower shell 13 (see FIGS. 1 and 2), and is pumped up by an oil pump 52 (described later) and passes through an oil passage 63 in the crankshaft 6 to reduce wear between mechanically contacting parts such as the compression mechanism 3, regulate the temperature of sliding parts, and improve sealing performance. An oil with excellent lubrication properties, electrical insulation, stability, refrigerant solubility, and low-temperature fluidity, as well as moderate viscosity, is suitable as the lubricating oil.

[0041] <Configuration of Compression Mechanism 3> The compression mechanism 3 shown in FIG. 2 is a compression mechanism that compresses a refrigerant. The compression mechanism 3 is a scroll compression mechanism that includes a fixed scroll 31 and an orbiting scroll 32. The fixed scroll 31 is made of metal such as cast iron, and includes a first base plate 311 and a first scroll body 312, as shown in FIG. 10. The first base plate 311 is disk-shaped, and has a discharge port 313 (see FIG. 2) formed in the center thereof, penetrating in the vertical direction. The first scroll body 312 protrudes from the L-side surface of the first base plate 311 to form a spiral wall, and its tip protrudes toward the L side.

[0042] 2 and fig. 10 As shown in FIG. 3, the fixed scroll 31 has a protrusion 314 that protrudes toward the lower shell 13 (L side) from the surface of the first base plate 311 on the side where the first spiral body 312 is formed, and a C-chamfer or R-chamfer 3141 is formed at the tip of the protrusion 314 on the lower shell 13 side, so that the protrusion width gradually increases from the tip. The phase of the fixed scroll 31 is determined by fitting the protrusion 314 into a groove 118 (see FIG. 3) formed in the main shell 11.

[0043] As shown in FIG. 3 , the surface of the first base plate 311 of the fixed scroll 31, which forms the first spiral body 312, is brought into contact with the first positioning surface 113 formed on the main shell 11, thereby determining the axial position of the fixed scroll 31. Furthermore, in this state, the 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 fitting, thereby determining the center position. As a result, the fixed scroll 31 can be held in the main shell 11 with its center position, axial height position, and phase determined. The fixed scroll 31 also has the function of separating high and low pressures inside the shell 11. Therefore, 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 must be pressurized around the entire circumference by shrink fitting to prevent refrigerant leakage. Therefore, the shrink fitting position is located on the first inner wall surface 111, where no groove 118 is formed.

[0044] 11, the second substrate 321 has a disk shape including one surface on which the second spiral body 322 is formed, the other surface on which at least a portion of the outer circumferential region serves as a sliding surface 3211, and a side surface 3212 located at the outermost radial position and connecting the one surface to the other surface, and the sliding surface 3211 is supported (borne) by the first frame 2 so as to be slidable on the thrust plate 24. The second spiral body 322 protrudes from one surface of the second substrate 321 to form a spiral wall, and its tip protrudes toward the U side.

[0045] The first scroll 312 of the fixed scroll 31 and the second scroll 322 of the orbiting scroll 32 are provided at their tip ends with sealing members to prevent refrigerant leakage. The cylindrical portion 323 is a cylindrical boss formed on the other surface of the second base plate 321, protruding toward the L side from approximately the center of the other surface. A rocking bearing (a so-called journal bearing) that rotatably supports a slider 71 (described later) is provided on the inner circumferential surface of the cylindrical portion 323, with its central axis parallel to the central axis of the crankshaft 6. The second Oldham groove 324 is an oval groove formed on the other surface of the second base plate 321. A pair of second Oldham grooves 324 are provided facing each other. The line connecting the pair of second Oldham grooves 324 is arranged perpendicular to the line connecting the pair of first Oldham grooves 215 shown in FIG. 9.

[0046] An Oldham ring 33 is provided in the Oldham receiving portion 214 (see FIG. 9) of the first frame 2. As shown in FIG. 12, the Oldham ring 33 includes a ring portion 331, first keys 332, and second keys 333. The ring portion 331 is ring-shaped. A pair of first keys 332 are formed on the L-side surface of the ring portion 331 so as to face each other, and are received in a pair of first Oldham grooves 215 of the first frame 2. A pair of second keys 333 are formed on the U-side surface of the ring portion 331 so as to face each other, and are received in a pair of second Oldham grooves 324 (see FIG. 11) of the orbiting scroll 32.

[0047] When the orbiting scroll 32 revolves due to the 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, thereby causing the Oldham ring 33 to prevent the orbiting scroll 32 from rotating on its axis. The first spiral body 312 of the fixed scroll 31 and the second spiral body 322 of the orbiting scroll 32 mesh with each other to form a compression chamber 34.

[0048] The volume of the compression chamber 34 decreases radially from the outside to the inside, so that the refrigerant is taken in from the outer end side of the volute and gradually compressed as it moves toward the center.

[0049] 2, the compression chamber 34 communicates with a discharge port 313 at the center of the fixed scroll 31. A muffler 35 having a discharge hole 351 is provided on the surface of one end side U of the fixed scroll 31, and a discharge valve 36 is also provided to open and close the discharge hole 351 in a predetermined manner to prevent backflow of the refrigerant.

[0050] The refrigerant may be, for example, a halogenated hydrocarbon having a carbon-carbon double bond, a halogenated hydrocarbon not having a carbon-carbon double bond, a hydrocarbon, or a mixture containing any of these. Examples of halogenated hydrocarbons having a carbon-carbon double bond include HFC refrigerants with zero ozone depletion potential and fluorocarbon-based low-GWP refrigerants, such as tetrafluoropropenes, represented by the chemical formula C3H2F4, such as HFO1234yf, HFO1234ze, and HFO1243zf. Examples of halogenated hydrocarbons not having a carbon-carbon double bond include refrigerants mixed with R32 (difluoromethane), R41, or the like, represented by the formula CH2F2. Examples of hydrocarbons include natural refrigerants such as propane and propylene. Examples of mixtures include mixed refrigerants obtained by mixing HFO1234yf, HFO1234ze, HFO1243zf, or the like with R32 or R41.

[0051] <Configuration of drive mechanism 4> As shown in FIG. 2, the drive mechanism 4 is provided on the L side of the first frame 2 inside the shell 1. The drive mechanism 4 includes a stator 41 and a rotor 42. The stator 41 is a ring-shaped stator formed by winding a winding around an iron core made of, for example, a plurality of laminated electromagnetic steel sheets, with an insulating layer interposed between them. The stator 41 is fixedly supported inside the main shell 11 by shrink fitting or the like. The rotor 42 is a cylindrical rotor that has a permanent magnet built into an iron core made of a plurality of laminated electromagnetic steel sheets and has a through-hole that passes through it in the vertical direction in the center, and is disposed 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. As shown in FIG. 2, the second frame 5 is provided on the L side of the drive mechanism 4 inside the shell 1 and is fixedly supported by a shrink fit, welding, or other suitable means on the inner peripheral surface of the L side of the main shell 11. The second frame 5 includes a sub-bearing 51 and an oil pump 52. The sub-bearing 51 is a ball bearing provided on the upper central portion of the second frame 5 and has a hole extending vertically through the center. The oil pump 52 is provided on the lower central portion of the second frame 5 and is disposed so that at least a portion of the oil pump 52 is immersed in the lubricating oil stored in the oil reservoir of the shell 1. While a ball bearing is exemplified as the sub-bearing 51 in this embodiment, a journal bearing may also be used.

[0053] <Configuration of crankshaft 6> The crankshaft 6 is a long, rod-shaped member made of metal, and includes a main shaft portion 61, an eccentric shaft portion 62, and an oil passage 63 as shown in FIG. 13. The main shaft portion 61 is a shaft that constitutes the main portion of the crankshaft 6, and is disposed so that its central axis coincides with the central 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 disposed on the U-side of the main shaft portion 61 so that its central axis is eccentric relative to the central axis of the main shaft portion 61. The oil passage 63 is disposed to penetrate vertically through the main shaft portion 61 and the eccentric shaft portion 62.

[0054] The crankshaft 6 has the U side of the main shaft portion 61 inserted into the main bearing portion 22 of the first frame 2, and the L side inserted and fixed into the sub-bearing portion 51 of the second frame 5. As a result, the eccentric shaft portion 62 is disposed inside the cylindrical portion 323, and the rotor 42 is disposed with its outer circumferential surface maintaining a predetermined gap with the inner circumferential surface of the stator 41. In addition, 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 to offset imbalance caused by the swing of the swing scroll 32.

[0055] <Bush 7 Configuration> The bushing 7 is made of a metal such as iron and is a connecting member that connects the orbiting scroll 32 and the crankshaft 6, as shown in FIG. 2. In this embodiment, as shown in FIG. 14, the bushing 7 is composed of two parts, a slider 71 and a balance weight 72. The slider 71 is a cylindrical member with a flange and is fitted into the eccentric shaft portion 62 (see FIG. 2) and the cylindrical portion 323 (see FIG. 11). The balance weight 72 is a donut-shaped member with a weight portion 721 that is approximately C-shaped when viewed from the U side. The balance weight 72 is provided eccentrically with respect to the center of rotation to offset the centrifugal force of the orbiting scroll 32. The balance weight 72 is fitted to the flange of the slider 71 by, for example, shrink fitting. The bushing 7 may also be a one-part product in which the slider 71 and the balance weight 72 are integrally machined, for example.

[0056] <Configuration of power supply unit 8> Power supply unit 8 is a power supply member that supplies power to the scroll compressor, and is formed on the outer peripheral surface of main shell 11 of shell 1, as shown in FIGS. 1 and 2. Power supply unit 8 includes a cover 81, a power supply terminal 82, and wiring 83. Cover 81 is a cover member with an opening at the bottom. Power supply terminal 82 is made of a metal member, and one end is provided inside cover 81 and the other end is provided inside shell 1. One end of wiring 83 is connected to power supply terminal 82, and the other end is connected to stator 41.

[0057] <Scroll compressor teeth How to adjust the tip clearance Next, a method for adjusting the clearance (tooth tip clearance) between the spiral tips and base plate of the fixed scroll 31 and the orbiting scroll 32 will be explained using Figure 15. Figure 15 is a diagram of Figure 4(a) with dimensions added. If the dimensions of each part are set as follows, the tooth tip clearance Q can be expressed by the following formula. Distance L between the first positioning surface 113 and the second positioning surface 116 Distance M between the first positioning surface 113 and the tip of the first spiral body 312 Thickness N of the second substrate 321 of the orbiting scroll 32 Thickness of thrust plate 24 T Distance P between the second positioning surface 116 and the flat surface 212 Tooth tip clearance Q L=M+Q+N+T+P ⇒ Q=LMNTP If the dimensions of each part are known through measurement, the target tooth tip clearance Q can be obtained by adjusting the thickness T of the thrust plate 24, which allows for the widest variety of mass production. This adjustment prevents refrigerant from leaking into the adjacent compression space through the gap between the volute tip and the base plate, reducing compressor losses.

[0058] Although exemplary embodiments are described herein, the various features, aspects, and functions described in the embodiments are not limited to application to a particular embodiment, but may be applied to the embodiments alone or in various combinations. Therefore, countless variations not illustrated are contemplated within the scope of the technology disclosed in the present specification, including, for example, modifying, adding, or omitting at least one component. [Explanation of symbols]

[0059] 1: shell, 11: main shell, 111: first inner wall surface, 1111: first straight pipe section, 1112: second straight pipe section, 1113: third straight pipe section, 1117: first connecting section, 1118: second connecting section, 1119: first machining mark, 1120: second machining mark, 1121: third machining mark, 112: first protrusion, 113: first positioning surface, 1131: recess, 114: second inner wall surface, 115: second protrusion, 116: second positioning surface, 116 1: recess, 117: third inner wall surface, 118: groove, 1181: chamfer, 12: upper shell, 13: lower shell, 14: suction pipe, 15: discharge pipe, 16: fixing base, 2: first frame, 21: main body, 211: accommodation space, 212: flat surface, 213: suction port, 214: Oldham accommodation portion, 215: first Oldham groove, 216: protrusion, 2161: chamfer, 22: main bearing portion, 221: shaft hole, 23: oil return pipe, 24: Thrust plate, 3: compression mechanism part, 31: fixed scroll, 311: first base plate, 3111: side surface, 312: first spiral body, 313: discharge port, 314: protrusion, 3141: chamfer, 32: orbiting scroll, 321: second base plate, 322: second spiral body, 3211: sliding surface, 3212: side surface, 323: cylindrical part, 324: second Oldham groove, 33: Oldham ring, 331: ring part, 332: first key part, 3 33: 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: auxiliary bearing portion, 52: oil pump, 6: crankshaft, 61: main shaft portion, 62: eccentric shaft portion, 63: oil passage, 7: bush, 71: slider, 72: balance weight, 721: weight portion, 8: power supply portion, 81: cover, 82: power supply terminal.

Claims

1. a scroll compressor including a compression mechanism having a fixed scroll and an orbiting scroll, a frame that slidably holds the orbiting scroll, a drive mechanism that slides the orbiting scroll, and a cylindrical main shell that houses the compression mechanism, the frame, and the drive mechanism, wherein the main shell has a first straight pipe portion extending along a central axis, a second straight pipe portion that extends along the central axis and has a smaller outer diameter than the first straight pipe portion, and a third straight pipe portion that extends along the central axis and has a smaller outer diameter than the second straight pipe portion, and wherein the fixed scroll is fixed within the first straight pipe portion, the frame is fixed within the second straight pipe portion, and the drive mechanism is fixed within the third straight pipe portion.

2. 2. The scroll compressor according to claim 1, wherein the first straight pipe portion has a wall thickness smaller than that of the second straight pipe portion.

3. 2. The scroll compressor according to claim 1, wherein the thickness of the first straight pipe section and the thickness of the third straight pipe section, whichever has a larger absolute difference from the thickness of the second straight pipe section, is smaller than the thickness of the third straight pipe section, which has a smaller absolute difference from the thickness of the second straight pipe section.

4. 2. The scroll compressor according to claim 1, further comprising: a first connecting portion connecting the first straight pipe portion and the second straight pipe portion; and a second connecting portion connecting the second straight pipe portion and the third straight pipe portion.

5. 2. The scroll compressor according to claim 1, further comprising: a first protrusion protruding from an inner wall surface of the first straight pipe section and positioning the fixed scroll; and a second protrusion protruding from an inner wall surface of the second straight pipe section and positioning the frame.

6. The scroll compressor according to claim 1 , wherein the first straight pipe section, the second straight pipe section, and the third straight pipe section have processing marks on their inner diameters or outer diameters.

7. A scroll compressor as described in claim 1, characterized in that it has a first connecting portion that connects the first straight pipe portion and the second straight pipe portion, and has welding marks on the inner diameter or outer diameter between the first connecting portion and the second straight pipe portion.

8. a first straight pipe section extending along a central axis of the main shell so that its outer diameter is larger than that of a second straight pipe section; a third straight pipe section extending along the central axis so that its outer diameter is smaller than that of the second straight pipe section; and a fixing step of fixing the fixed scroll to the inner diameter of the first straight pipe section, fixing the frame to the inner diameter of the second straight pipe section, and fixing the drive mechanism section to the inner diameter of the third straight pipe section.

Images