Scroll compressor

Abstract

In a scroll compressor (100), a fixed scroll (31) has a protrusion part (31GG) having a first outer peripheral surface (31G2) and a second outer peripheral surface (31G1) on a lower side of the protrusion part (31GG) in an axial direction (Y). An upper shell (12) has a first step part (12NN) on a lower side in the axial direction (Y) on an inner peripheral surface thereof on a middle shell (11) side. An upper end surface (31F3) of the protrusion part (31GG) contacts a first step surface (12F4) of the first step part (12NN), and a lower end surface (31F2) of the protrusion part (31GG) contacts and is fixed to an upper end surface (11F1) of the middle shell (11). The second outer peripheral surface (31G1) of the fixed scroll (31) contacts a first inner peripheral surface (11N1) of the middle shell (11). A first inner peripheral surface (12N2) of the first step part (12NN) of the upper shell (12) contacts a first outer peripheral surface (11G1) of the middle shell (11).

Description

Scroll Compressor

[0001] The present disclosure relates to scroll compressors.

[0002] In a scroll compressor, an orbiting scroll is supported on a frame fixed inside a shell, and a fixed scroll is fixed to the frame with bolts or the like so as to face the orbiting scroll. A crankshaft is attached to the orbiting scroll, and when the crankshaft is rotated, the orbiting scroll moves in an orbital motion relative to the fixed scroll, compressing the refrigerant in a compression chamber formed by the orbiting scroll and the fixed scroll. Because a compression chamber that compresses the refrigerant is formed between the fixed scroll and the orbiting scroll, the positional accuracy of the fixed scroll relative to the orbiting scroll is important, and a method for easily fixing the fixed scroll to the frame with high accuracy is required.

[0003] In conventional scroll compressors, the peripheral wall of the frame extends toward the fixed scroll, and a cylindrical portion provided on the outside of the fixed wrap of the fixed scroll is fitted onto the inner peripheral surface of the tip of the peripheral wall. A flange portion provided on the outermost peripheral part of the frame and a flange portion provided on the outermost peripheral part of the peripheral wall of the fixed scroll are welded to the end face of the cylindrical center shell and a lid cap that covers the open end face of the center shell, thereby fixing the fixed scroll and frame together, making it easy to center the frame and fixed scroll, and positional accuracy is ensured by overlapping the flange portion provided on the outermost peripheral part of the frame and the flange portion provided on the outermost peripheral part of the fixed scroll (see, for example, Patent Document 1).

[0004] Japanese Patent Application Laid-Open No. 2018-189027

[0005] Conventional scroll compressors require a cylindrical portion provided on the outer side of the peripheral wall of the frame and the fixed wrap of the fixed scroll that corresponds to the inner diameter side of the peripheral wall of the frame, which results in a large frame and fixed scroll, which increases costs.Furthermore, when the same cylindrical housing is used, there is a problem that the compression chamber becomes small due to the provision of this mechanism, resulting in a small compression volume.

[0006] The present disclosure discloses a technique for solving the above-described problems, and aims to provide a scroll compressor that can increase the refrigerant compression volume without increasing the size of the device.

[0007] a middle shell accommodating the frame, the frame, the frame, the frame, the frame, the frame, the frame, the fixed scroll, and the fixed scroll; a middle shell accommodating the frame, the frame, the frame, the frame, the frame, the fixed scroll, and the fixed scroll; an upper shell accommodating the middle shell and sealing the middle shell above the fixed scroll; the fixed scroll having a protruding portion axially between its outer peripheral surface and having a first outer peripheral surface, and a second outer peripheral surface axially below the protruding portion; the upper shell having a first step portion on its inner peripheral surface facing the middle shell, the first step portion having a larger inner diameter on the axially lower side; the fixed scroll having an upper end surface in the axial direction of the protruding portion in contact with the first step surface of the first step portion of the upper shell and a lower end surface in the axial direction of the protruding portion in contact with the upper end surface in the axial direction of the middle shell; and the second outer peripheral surface of the fixed scroll being in contact with a first inner peripheral surface on the axially upper side of the middle shell. A first inner peripheral surface on the axially lower side of the first step portion of the upper shell is formed in contact with a first outer peripheral surface on the axially upper side of the middle shell.

[0008] According to the scroll compressor of the present disclosure, the refrigerant compression volume can be increased without increasing the size of the device.

[0009] 1. A cross-sectional view showing the configuration of a scroll compressor according to embodiment 1. 2. An enlarged view of a portion surrounded by dotted line S1 of the scroll compressor shown in FIG. 1. 3. An enlarged view of a portion surrounded by dotted line S2 of the scroll compressor shown in FIG. 2. 4. An enlarged view of another example of the portion surrounded by dotted line S2 of the scroll compressor shown in FIG. 2. 5A is a plan view showing another configuration of the fixed scroll of the scroll compressor according to embodiment 1, and FIG. 5B is a cross-sectional view taken along line II of FIG. 5A. 6. A partial cross-sectional view showing the configuration of a scroll compressor according to embodiment 2. 7. A partial cross-sectional view showing the configuration of a scroll compressor according to embodiment 3. 8. A partial cross-sectional view showing the configuration of a scroll compressor according to embodiment 4. 9. A partial cross-sectional view showing the configuration of the scroll compressor shown in FIG. 8. 10. A partial cross-sectional view showing the configuration of a comparative scroll compressor. 11. A partial cross-sectional view showing another configuration of the scroll compressor according to embodiment 1. 12. A partial cross-sectional view showing the configuration of a scroll compressor according to embodiment 5. 13. A diagram showing the relationship between the formation positions of welded portions and the deformation amounts of the fixed scroll and the frame of the scroll compressor according to embodiment 5. 14. A partial cross-sectional view showing the configuration of a scroll compressor according to embodiment 6. 15. An enlarged view of a portion surrounded by dotted line S3 of the scroll compressor shown in FIG. 14.

[0010] Embodiment 1. Figure 1 is a cross-sectional view showing the configuration of a scroll compressor according to embodiment 1. Figure 2 is an enlarged view of a portion of the scroll compressor shown in Figure 1 surrounded by dotted line S1. Figure 3 is an enlarged view of a portion of the scroll compressor shown in Figure 2 surrounded by dotted line S2. Figure 4 is an enlarged view of another example of the portion of the scroll compressor shown in Figure 2 surrounded by dotted line S2. Figure 5A is a plan view showing another configuration of the fixed scroll of the scroll compressor according to embodiment 1, and Figure 5B is a cross-sectional view taken along line II shown in Figure 5A. Figure 11 is a partial cross-sectional view showing another configuration of the scroll compressor according to embodiment 1.

[0011] A scroll compressor 100 according to the first embodiment will now be described with reference to the drawings. First, as shown in FIG. 1 , in the scroll compressor 100, the up-down direction on the paper surface is the axial direction Y (corresponding to the axial direction Y of the crankshaft 6, which will be described later), and the left-right direction on the paper surface perpendicular to the axial direction Y is the radial direction X. The "U side" in the drawing indicates the upper side in the axial direction Y, and the "L side" in the drawing indicates the lower side in the axial direction Y. Note that the U side and L side shown in other drawings refer to the U side and L side in FIG. 1 . Note that this relationship is similar in the following embodiments, and therefore description thereof will be omitted as appropriate.

[0012] A scroll compressor 100 according to the first embodiment will be described with reference to the accompanying drawings. As shown in Fig. 1, the scroll compressor 100 mainly comprises a shell 1 having a middle shell 11, an upper shell 12 equipped with a discharge pipe 15 disposed on the U-side of the middle shell 11, and a lower shell 13 disposed on the L-side of the middle shell 11, a crankshaft 6 supported by a bearing 20 of the middle shell 11, and a drive unit 4 that rotates and drives the crankshaft 6.

[0013] The compressor further comprises a frame 2 fixed to the middle shell 11, the frame 2 comprising an orbiting scroll 32 provided on the eccentric shaft portion 62 of the crankshaft 6, a compression chamber 34 formed for compressing the refrigerant, and a bearing 20 supporting the orbiting scroll 32 and the crankshaft 6, and a subframe 50 fixed to the middle shell 11.

[0014] First, the operation of the scroll compressor 100 configured as described above will be described. The crankshaft 6 is rotated by the operation of the drive unit 4, and the refrigerant flows through the frame 2 into the compression chamber 34. The orbiting scroll 32 attached to the eccentric shaft portion 62 of the crankshaft 6 performs an orbiting motion, and the refrigerant is compressed in the compression chamber 34. The compressed refrigerant flows into the discharge pipe 15 via the fixed scroll 31.

[0015] Next, the details of the configuration of each part will be described with reference to Fig. 2, which is an enlarged view of the part surrounded by dotted line S1 of scroll compressor 100 shown in Fig. 1, and Fig. 3, which is an enlarged view of the part surrounded by dotted line S2 of scroll compressor 100 shown in Fig. 3. Note that Fig. 3 shows only the upper left part in the radial direction X on the paper surface of Fig. 2, but the parts described in Fig. 3 are formed symmetrically with the left part on the right part on the paper surface in the radial direction X, as shown in Fig. 2 or Fig. 1.

[0016] 3, the fixed scroll 31 has a protrusion 31GG that protrudes outward in the radial direction X between the outer peripheral surface and the axial direction Y. The protrusion 31GG has a first outer peripheral surface 31G2. The fixed scroll 31 has a second outer peripheral surface 31G1 below the protrusion 31GG in the axial direction Y. An upper end surface 31F3 is above the protrusion 31GG in the axial direction Y, and a lower end surface 31F2 is below the protrusion 31GG in the axial direction Y.

[0017] The first outer peripheral surface 31G2 of the protruding portion 31GG of the fixed scroll 31 is the portion having the largest outer diameter in the fixed scroll 31. Therefore, as shown in FIG. 2 , the outer diameter W1 of the first outer peripheral surface 31G2 of the protruding portion 31GG of the fixed scroll 31 is formed to be larger than the outer diameter W2 of the second outer peripheral surface 31G1 of the fixed scroll 31.

[0018] The upper shell 12 has a first step portion 12NN on its inner circumferential surface facing the middle shell 11, the inner diameter of which increases downward in the axial direction Y. The upper shell 12 has a first step surface 12F4 of the first step portion 12NN, a first inner circumferential surface 12N2 below the first step portion 12NN in the axial direction Y, a second inner circumferential surface 12N3 above the first step portion 12NN in the axial direction Y, and a lower end surface 12F5 at the lower end in the axial direction Y. Therefore, the inner diameter H1 of the first inner circumferential surface 12N2 of the upper shell 12 is larger than the inner diameter H2 of the second inner circumferential surface 12N3 of the upper shell 12.

[0019] The outer diameter W1 of the first outer peripheral surface 31G2 of the fixed scroll 31 is formed to be smaller than the inner diameter H1 of the first inner peripheral surface 12N2 of the upper shell 12. With this configuration, a gap is generated in the radial direction X between the first inner peripheral surface 12N2 of the upper shell 12 and the first outer peripheral surface 31G2 of the protruding portion 31GG of the fixed scroll 31. By configuring the gap in this manner, the upper shell 12 and the first outer peripheral surface 31G2 of the protruding portion 31GG of the fixed scroll 31 do not come into contact with each other, which makes it easier to fit the upper shell 12 into the middle shell 11.

[0020] In each figure, the point where the first step surface 12F4 of the upper shell 12 and the fixed scroll 31 contact is shown as the upper end surface 31F3 of the protrusion 31GG of the fixed scroll 31, but any surface can be used as long as it is an upper end surface (end surface perpendicular to the axial direction Y) above the protrusion 31GG of the fixed scroll 31, and is not limited to the respective figures.

[0021] The middle shell 11 has a first outer peripheral surface 11G1 on the upper side in the axial direction Y, an upper end surface 11F1 in the axial direction Y, and a second step portion 11NN on the lower side of the inner peripheral surface in the axial direction Y, where the inner diameter decreases. The middle shell 11 has a second step surface 11F0 of the second step portion 11NN, a first inner peripheral surface 11N1 above the second step portion 11NN in the axial direction Y, and a second inner peripheral surface 11N0 below the second step portion 11NN in the axial direction Y. Therefore, the inner diameter H3 of the first inner peripheral surface 11N1 of the middle shell 11 is larger than the inner diameter H4 of the second inner peripheral surface 11N0 of the middle shell 11. The frame 2 has an outer peripheral surface 2G0 and a lower end surface 2F1 perpendicular to the outer peripheral surface 2G0 below the outer peripheral surface 2G0 in the axial direction Y.

[0022] In addition, the first step surface 12F4 of the upper shell 12, the upper end surface 31F3 of the protrusion 31GG, the lower end surface 31F2 of the protrusion 31GG, the upper end surface 11F1 of the middle shell 11, the second step surface 11F0 of the second step portion 11NN of the middle shell 11, and the lower end surface 2F1 of the frame 2 are formed parallel to each other in the axial direction Y.

[0023] In addition, the first inner peripheral surface 12N2 of the upper shell 12, the second inner peripheral surface 12N3 of the upper shell 12, the first outer peripheral surface 31G2 of the protrusion 31GG, the second outer peripheral surface 31G1 of the fixed scroll 31, the first outer peripheral surface 11G1 of the middle shell 11, and the first inner peripheral surface 11N1 of the middle shell 11 are formed perpendicular to the first step surface 12F4 of the upper shell 12, the upper end surface 31F3 of the protrusion 31GG, the lower end surface 31F2 of the protrusion 31GG, the upper end surface 11F1 of the middle shell 11, the second step surface 11F0 of the second step portion 11NN of the middle shell 11, and the lower end surface 2F1 of the frame 2, i.e., perpendicular to the axial direction Y.

[0024] The fixed scroll 31 is fixed by being sandwiched between the upper end surface 31F3 of the protrusion 31GG and the first step surface 12F4 of the first step portion 12NN of the upper shell 12, with the lower end surface 31F2 of the protrusion 31GG contacting the upper end surface 11F1 of the middle shell 11 in the axial direction Y. Furthermore, the second outer peripheral surface 31G1 of the fixed scroll 31 is formed in contact with the first inner peripheral surface 11N1 of the middle shell 11. Furthermore, the first inner peripheral surface 12N2 of the upper shell 12 is formed in contact with the first outer peripheral surface 11G1 of the middle shell 11.

[0025] In this way, the upper end surface 31F3 and the lower end surface 31F2 of the protrusion 31GG of the fixed scroll 31 contact the first step surface 12F4 of the first step portion 12NN of the upper shell 12 and the upper end surface 11F1 of the middle shell 11, respectively, fixing their relative positions, and the compression chamber 34 is made airtight by the second outer peripheral surface 31G1 of the fixed scroll 31 and the first inner peripheral surface 11N1 of the middle shell 11.

[0026] The second outer peripheral surface 31G1 of the fixed scroll 31 is formed in contact with the first inner peripheral surface 11N1 of the middle shell 11 to airtightly seal the compression chamber 34, and the second outer peripheral surface 31G1 of the fixed scroll 31 is formed continuously 360 degrees in the circumferential direction along the first inner peripheral surface 11N1 of the middle shell 11. The second outer peripheral surface 31G1 of the fixed scroll 31 and the first inner peripheral surface 11N1 of the middle shell 11 are fixed by shrink fitting.

[0027] In this way, the second outer peripheral surface 31G1 of the fixed scroll 31 exists continuously for 360 degrees along the first inner peripheral surface 11N1 of the middle shell 11, so that the second outer peripheral surface 31G1 of the fixed scroll 31 is easy to machine.

[0028] Furthermore, the frame 2 is fixed in contact with the second step surface 11F0 of the second step portion 11NN of the middle shell 11 and the first inner peripheral surface 11N1 of the middle shell 11. Specifically, the lower end surface 2F1 of the frame 2 is fixed in contact with the second step surface 11F0 of the second step portion 11NN of the middle shell 11, and the outer peripheral surface 2G0 of the frame 2 is fixed in contact with the first inner peripheral surface 11N1 of the middle shell 11.

[0029] In this way, the outer peripheral surface 21G0 of the frame 2 and the second outer peripheral surface 31G1 of the fixed scroll 31 contact and are fixed to the same first inner peripheral surface 11N1 of the middle shell 11, allowing for highly accurate positioning and preventing refrigerant leakage. Furthermore, the middle shell 11 does not require a step for fixing the fixed scroll 31, and the wall thickness of the middle shell 11 does not need to be thinned, which reduces the material costs and processing costs of the middle shell 11.

[0030] The first step surface 12F4 of the upper shell 12 is placed on the upper end surface 31F3 of the protrusion 31GG of the fixed scroll 31, and the lower end surface 12F5 of the upper shell 12 and the first outer peripheral surface 11G1 of the middle shell 11 are welded together to form a weld 99 (see FIG. 3 ), thereby maintaining airtightness between the inside and outside of the upper shell 12 and the middle shell 11. The weld 99 is provided continuously 360 degrees circumferentially along the first outer peripheral surface 11G1 of the middle shell 11.

[0031] Furthermore, if a point A (see FIG. 3) is defined as a contact point between the outer peripheral surface 2G0 of the frame 2 and the first inner peripheral surface 11N1 of the middle shell 11, and a point B (see FIG. 3) is defined as a contact point between the second outer peripheral surface 31G1 of the fixed scroll 31 and the first inner peripheral surface 11N1 of the middle shell 11, the weld 99 is desirably located between points A and B in the axial direction Y. Forming the weld 99 at this position can prevent deformation of the frame 2 and the fixed scroll 31, thereby preventing refrigerant leakage.

[0032] The welded portion 99 is preferably formed by using two or more welding torches, starting welding points at two or more positions that are 180 degrees apart in the radial direction X, and simultaneously welding in the same circumferential direction. With this configuration, two or more positions that are 180 degrees apart serve as weld starting points and are fixed simultaneously at the beginning of welding. This prevents the portion of the upper shell 12 that is 180 degrees apart from the welded portion from floating from the middle shell 11 due to thermal contraction caused by welding, and firmly fixes the fixed scroll 31, thereby improving the performance of the scroll compressor 100.

[0033] 11 , the first inner peripheral surface 12N2 of the upper shell 12 is provided with a recess 12U recessed radially outward only at a position facing the first outer peripheral surface 31G2 of the fixed scroll 31. The lower end surface 31F2 of the protrusion 31GG in the axial direction Y is fixed in contact with the entire upper end surface 11F1 of the middle shell 11 in the axial direction Y. By providing the recess 12U, the protrusion 31GG is formed to extend outward in the radial direction X, compared to the case of FIG. 3 , and the lower end surface 31F2 of the protrusion 311GG can be fixed in contact with the entire upper end surface 11F1 of the middle shell 11. Therefore, a larger contact area can be secured in this portion compared to the case of FIG. 3 .

[0034] In the scroll compressor 100 configured as described above, the frame 2 and the middle shell 11 can be fixed to each other by, for example, forming the outer diameter of the outer peripheral surface 2G0 of the frame 2 larger than the inner diameter of the first inner peripheral surface 11N1 of the middle shell 11 and fixing them by shrink fitting or cold fitting. Alternatively, the middle shell 11 and the frame 2 can be fixed by full penetration welding using a laser or the like. Alternatively, holes can be formed in the middle shell 11 at positions corresponding to the frame 2 and fixed by welding. Alternatively, the frame 2 can be fixed by press-fitting the middle shell 11 from the upper side to the lower side (from the U side to the L side) in the axial direction Y of the middle shell 11. However, the methods for fixing the middle shell 11 and the frame 2 are not limited to these.

[0035] As a method for fixing and sealing the fixed scroll 31 to the middle shell 11, for example, the outer diameter of the second outer peripheral surface 31G1 of the fixed scroll 31 is formed larger than the inner diameter of the first inner peripheral surface 11N1 of the middle shell 11, and the fixed scroll 31 is fixed by shrink fitting or cold fitting. The middle shell 11 and the fixed scroll 31 may also be fixed by penetration welding using a laser or the like. The fixed scroll 31 may also be fixed to the middle shell 11 by press-fitting the fixed scroll 31 from the upper side to the lower side (from the U side to the L side) in the axial direction Y of the middle shell 11. However, the method for fixing and sealing the fixed scroll 31 to the middle shell 11 is not limited to this.

[0036] In addition, although the example has been shown in which the compression chamber 34 is made airtight by the second outer peripheral surface 31G1 of the fixed scroll 31 and the first inner peripheral surface 11N1 of the middle shell 11, the compression chamber 34 may be kept airtight by, for example, the lower end surface 31F2 of the protruding portion 31GG of the fixed scroll 31 and the upper end surface 11F1 of the middle shell 11. In this case, it is desirable to sandwich a sealing material between the lower end surface 31F2 of the protruding portion 31GG of the fixed scroll 31 and the upper end surface 11F1 of the middle shell 11.

[0037] Next, a configuration example for maintaining airtightness on the U side and the L side of the fixed scroll 31 will be described with reference to Fig. 4, which is an enlarged view of another example of the portion surrounded by the dotted line S2 of the scroll compressor 100 shown in Fig. 2. For example, a welded portion 201 is formed at the contact point between the middle shell 11 and the fixed scroll 31 by shrink fitting, cold fitting, laser welding, or the like, of the second outer peripheral surface 31G1 of the fixed scroll 31 to the first inner peripheral surface 11N1 of the middle shell 11, thereby maintaining airtightness on the U side and the L side of the fixed scroll 31.

[0038] A recess is provided on the first outer peripheral surface 31G2 of the fixed scroll 31, and a seal portion 202 such as an O-ring is placed therein to maintain airtightness on the U side and the L side of the fixed scroll 31.

[0039] In order to avoid interference, it is preferable to chamfer or round the corners below. a corner at the boundary between the first step surface 12F4 of the upper shell 12 and the second inner peripheral surface 12N3; a corner at the boundary between the lower end surface 12F5 of the upper shell 12 and the outer peripheral surface 12G1 of the upper shell 12; a corner at the boundary between the upper end surface 31F3 of the protruding portion 31GG of the fixed scroll 31 and the first outer peripheral surface 31G2 of the protruding portion 31GG; a corner at the boundary between the lower end surface 31F2 of the protruding portion 31GG of the fixed scroll 31 and the first outer peripheral surface 31G2 of the protruding portion 31GG; a corner at the boundary between the second outer peripheral surface 31G1 of the fixed scroll 31 and the lower end surface 31F4 of the fixed scroll 31; a corner at the boundary between the upper end surface 11F1 of the middle shell 11 and the first inner peripheral surface 11N1 of the middle shell 11; a corner at the boundary between the upper end surface 11F1 of the middle shell 11 and the first outer peripheral surface 11G1 of the middle shell 11 a corner at the boundary between the second step surface 11F0 of the middle shell 11 and the second inner peripheral surface 11N0 of the middle shell 11; a corner at the boundary between the outer peripheral surface 2G0 of the frame 2 and the lower end surface 2F1 of the frame 2; and a corner at the boundary between the outer peripheral surface 2G0 of the frame 2 and the U-side surface in contact with the outer peripheral surface 2G0.

[0040] Furthermore, when fixing the fixed scroll 31 to the middle shell 11, it is necessary to determine the phase of the fixed scroll 31 with respect to the frame 2. As a method for determining the phase, pin holes may be provided in each of the fixed scroll 31 and the middle shell 11, and the scrolls may be fixed with pins.

[0041] Furthermore, the protrusion 31GG of the fixed scroll 31 does not need to be formed continuously 360 degrees in the circumferential direction along the first inner circumferential surface 12N2 of the upper shell 12. Another example will be described with reference to Fig. 5. As shown in Fig. 5A, for example, the protrusion 31GG is formed discontinuously along the first inner circumferential surface 12N2 of the upper shell 12 and is divided into four. The fixed scroll 31 includes a first protrusion 31GA, a second protrusion 31GB, a third protrusion 31GC, and a fourth protrusion 31GD, each of which has a first outer peripheral surface 31G2 with an outer diameter W1 larger than the outer diameter W2 of the second outer peripheral surface 31G1.

[0042] In the radial direction X of the fixed scroll 31, there are recesses between the first protruding portion 31GA, the second protruding portion 31GB, the third protruding portion 31GC, and the fourth protruding portion 31GD. The recesses are formed by a die used during casting or forging, or by cutting or other processes. In this way, by dividing the protruding portion 31GG into, for example, the first protruding portion 31GA, the second protruding portion 31GB, the third protruding portion 31GC, and the fourth protruding portion 31GD, it is possible to control the location at which the fixed scroll 31 receives force via the upper shell 12 when the welded portion 99 contracts. Forming recesses around the pin holes that determine the phase of the frame 2 and the fixed scroll 31 reduces the load on the pin holes, thereby suppressing deformation of the pin holes and phase misalignment between the frame 2 and the fixed scroll 31, thereby improving the performance of the scroll compressor 100.

[0043] In addition, in the above-mentioned Patent Document 1, the center shell and the cover cap are welded together, sandwiching the fixed scroll and frame between the end face of the center shell and the cover cap to secure the fixed scroll. When welding, the welding is performed in a circular motion from the starting point. However, the closer to the starting point, the greater the thermal contraction due to welding because the center shell and the cover cap are not yet secured, and the closer to the end point, the smaller the thermal contraction due to the constraint caused by the weld near the starting point. Thermal contraction near the starting point causes the 180-degree opposite side of the cover cap to lift off the fixed scroll, widening the gap between the orbiting scroll and the fixed scroll, causing leakage of compressed refrigerant and reducing the performance of the scroll compressor.

[0044] In contrast, since the present embodiment is configured as described above, there are more fixing points than in the conventional case, and by clamping only the fixed scroll 31, the fixed scroll 31 can be firmly fixed, preventing the fixed scroll 31 from floating, and maintaining a small gap between the oscillating scroll 32 and the fixed scroll 31, thereby preventing a decrease in the performance of the scroll compressor 100.

[0045] The scroll compressor of the first embodiment configured as described above comprises: an orbiting scroll; a frame that slidably holds the orbiting scroll; a fixed scroll that forms a compression chamber together with the orbiting scroll; a middle shell that houses the frame, the orbiting scroll, and the fixed scroll; and an upper shell that seals the middle shell above the fixed scroll, wherein the fixed scroll has a protruding portion that protrudes radially outward between its outer peripheral surface in the axial direction and has a first outer peripheral surface, and a second outer peripheral surface axially below the protruding portion, and the upper shell has, on its inner peripheral surface facing the middle shell, a first step portion whose inner diameter increases on the axially lower side, and the fixed scroll is fixed such that an upper axial end surface of the protruding portion contacts a first step surface of the first step portion of the upper shell and a lower axial end surface of the protruding portion contacts an upper axial end surface of the middle shell, and the second outer peripheral surface of the fixed scroll is formed in contact with a first inner peripheral surface on the axial upper side of the middle shell, The first inner peripheral surface of the axially lower side of the first step portion of the upper shell is formed in contact with the first outer peripheral surface of the axially upper side of the middle shell. This allows the fixed scroll to be fixed by the middle shell and the upper shell, eliminating the need to form a separate outer peripheral wall on the frame and ensuring a larger area for the orbiting scroll. This increases the refrigerant compression volume without increasing the size of the device. Furthermore, by sandwiching only the fixed scroll between the middle shell and the upper shell, the fixing force of the fixed scroll can be increased compared to conventional scroll compressors, allowing the gap between the orbiting scroll and the fixed scroll to be maintained small, improving the performance of the scroll compressor. Furthermore, misalignment of the fixed scroll is reduced, reducing refrigerant leakage and improving performance.

[0046] Furthermore, since the outer diameter of the first outer peripheral surface of the fixed scroll is smaller than the inner diameter of the first inner peripheral surface below the first step portion of the upper shell, the upper shell can be easily assembled to the middle shell.

[0047] Furthermore, the middle shell has a second step portion whose inner diameter is smaller axially downward than the first inner peripheral surface of the middle shell, and the frame is fixed in contact with the second step surface of the second step portion of the middle shell and the first inner peripheral surface of the middle shell, so that the gap between the orbiting scroll and the fixed scroll can be controlled with higher precision, refrigerant leakage is reduced, the performance of the scroll compressor is improved, and processing is easier.

[0048] Furthermore, the second outer peripheral surface of the fixed scroll is formed continuously 360 degrees in the circumferential direction, and the second outer peripheral surface of the fixed scroll and the first inner peripheral surface of the middle shell are fixed by shrink fitting, which increases the fixing force of the fixed scroll, further reduces misalignment of the fixed scroll, further reduces refrigerant leakage, further improves performance, and makes processing easier.

[0049] Furthermore, the axial lower end surface of the upper shell and the middle shell are fixed by welding at a position axially lower than the upper end surface of the middle shell, so the contraction force of the weld increases the clamping force of the fixed scroll. Furthermore, the contraction of the weld presses the fixed scroll against the upper end surface of the middle shell via the first step surface of the upper shell, thereby fixing the fixed scroll to the middle shell. By increasing the number of fixing points compared to conventional methods and clamping only the fixed scroll 31, the fixed scroll can be firmly fixed, preventing the fixed scroll from floating, maintaining a small gap between the orbiting scroll and the fixed scroll, and preventing a decrease in scroll compressor performance.

[0050] Furthermore, because the high-pressure areas can be enclosed by the upper shell and fixed scroll, and the middle shell is the only low-pressure area, the load on the middle shell due to the internal refrigerant pressure can be reduced. This improves the reliability of the scroll compressor, and reduces costs by reducing the thickness of the middle shell. Furthermore, because bolts are not required to secure the fixed scroll, the number of parts can be reduced.

[0051] Furthermore, the first inner peripheral surface of the upper shell has a recess recessed radially outward only at a position facing the first outer peripheral surface of the fixed scroll, and the axial lower end surface of the protruding portion is fixed in contact with the entire axial upper end surface of the middle shell, thereby ensuring a large contact area between the axial lower end surface of the protruding portion and the axial upper end surface of the middle shell, preventing one-sided contact of the fixed scroll and increasing the holding force of the fixed scroll. Also, the fixed scroll can be easily installed on the upper end surface of the middle shell during manufacturing.

[0052] Embodiment 2. Figure 6 is a partial cross-sectional view showing the configuration of a scroll compressor according to embodiment 2. A scroll compressor 100 according to embodiment 2 will be described with reference to Figure 6. In Figure 6, parts that are the same as those in embodiment 1 above are assigned the same reference numerals and omitted. In embodiment 2, description of parts that are the same as those in embodiment 1 above will be omitted as appropriate, and the description will focus on parts that are different from embodiment 1 above.

[0053] As shown in Fig. 6 , a first groove 88 recessed in the radial direction X is formed in the first outer peripheral surface 31G2 of the protruding portion 31GG of the fixed scroll 31. Note that the first groove 88 does not penetrate in the radial direction X. It is desirable that the first groove 88 be formed continuously 360 degrees in the circumferential direction along the first outer peripheral surface 31G2 of the protruding portion 31GG, but this is not limited to this. It is preferable that a position D88 in the radial direction X of the bottom surface of the first groove 88 is located radially inward of a position L1 in the radial direction X of the second inner peripheral surface 12N3 of the upper shell 12.

[0054] Furthermore, a second groove portion 89 is formed in the lower end surface 31F4 of the fixed scroll 31, recessed in the axial direction Y and further outward in the radial direction X than the scroll wrap 311 of the scroll compressor 100. The second groove portion 89 does not penetrate the fixed scroll 31 in the axial direction Y. It is desirable that the second groove portion 89 be formed continuously 360 degrees in the circumferential direction in the lower end surface 31F4 of the fixed scroll 31, but this is not limited to this. It is preferable that a position D89 in the axial direction Y of the bottom surface of the second groove portion 89 is higher in the axial direction Y than a position D87 in the axial direction Y of the lower end surface 31F2 of the protruding portion 31GG of the fixed scroll 31.

[0055] When the fixed scroll 31 is formed as described above, when forming a welded portion 99 at which the lower end surface 12F5 of the upper shell 12 and the first outer peripheral surface 11G1 of the middle shell 11 are fixed by welding, the welded portion 99 shrinks, and the second outer peripheral surface 31G1 of the fixed scroll 31 receives a force mainly inward in the radial direction X via the first inner peripheral surface 11N1 of the middle shell 11, and the upper end surface 31F3 of the protrusion 31GG of the fixed scroll 31 receives a force mainly upward in the axial direction Y via the first step surface 12F4 of the upper shell 12.

[0056] By providing first grooves 88 and second grooves 89 that correspond to these forces, the portions between the grooves 88, 89 and the locations where the forces act are intentionally deformed significantly, thereby suppressing deformation of the center (referring to the center in the axial direction Y and the radial direction X) of the fixed scroll 31. Because the center of the fixed scroll 31 is under high pressure, compressed refrigerant is likely to leak from the gap between the fixed scroll 31 and the orbiting scroll 32. By suppressing deformation of the center of the fixed scroll 31, the gap between the orbiting scroll 32 and the fixed scroll 31 can be kept small, and degradation of the performance of the scroll compressor 100 can be suppressed.

[0057] In addition, the center of the fixed scroll 31 becomes hot, causing a large amount of expansion, which causes the oscillating scroll 32 and the fixed scroll 31 to press against each other.If the amount of expansion is large, they will not be able to slide and may seize, causing malfunctions.However, by suppressing deformation of the center of the fixed scroll 31, an appropriate clearance can be maintained and malfunctions can be suppressed.

[0058] The scroll compressor of embodiment 2 configured as described above achieves the same effects as embodiment 1 described above, and since a first groove portion that is recessed in the radial direction is formed in the first outer peripheral surface of the fixed scroll, the first groove portion suppresses the force that the second outer peripheral surface of the fixed scroll receives radially inward via the first inner peripheral surface of the middle shell, thereby suppressing deformation of the fixed scroll.

[0059] Furthermore, a second groove portion recessed axially upward is formed on the lower axial end surface of the fixed scroll, radially outward of the scroll wrap of the scroll compressor.This second groove portion suppresses the force that the upper end surface of the protruding portion of the fixed scroll receives, mainly in the axial upward direction, via the first step surface of the upper shell, thereby suppressing deformation of the fixed scroll.

[0060] Embodiment 3. Figure 7 is a partial cross-sectional view showing the configuration of a scroll compressor according to embodiment 3. A scroll compressor 100 according to embodiment 3 will be described with reference to Figure 7. In Figure 7, parts that are the same as those in the above-described embodiments are given the same reference numerals and omitted. In addition, in embodiment 3, description of parts that are the same as those in the above-described embodiments will be omitted as appropriate, and the description will focus on parts that are different from the above-described embodiments.

[0061] As shown in Figure 7, the middle shell 11 has a second step portion 11NN on its inner surface on the lower side in the axial direction Y, where the inner diameter of the first inner surface 11N1 of the middle shell 11 is smaller, and a third step portion 11NM on its inner surface above the second step portion 11NN in the axial direction Y, between the fixed scroll 31 and the frame 2, where the inner diameter of the first inner surface 11N1 is smaller.

[0062] A third inner peripheral surface 11N11 is formed which is above the second step surface 11F0 of the second step portion 11NN of the middle shell 11 in the axial direction Y and below the third step surface 11F11 of the third step portion 11NM in the axial direction Y.

[0063] The frame 2 is fixed in contact with the second step surface 11F0 of the second step portion 11NN of the middle shell 11 and the third inner peripheral surface 11N11 of the middle shell 11. Specifically, the lower end surface 2F1 of the frame 2 is fixed in contact with the second step surface 11F0 of the second step portion 11NN of the middle shell 11, and the outer peripheral surface 2G0 of the frame 2 is fixed in contact with the third inner peripheral surface 11N11 of the middle shell 11.

[0064] As a fixing method, for example, the outer diameter of the outer peripheral surface 2G0 of the frame 2 is made larger than the inner diameter of the third inner peripheral surface 11N11 of the middle shell 11, and shrink fitting or chill fitting is performed. Alternatively, the middle shell 11 and the frame 2 are welded together using a laser or the like. Alternatively, holes may be formed in the middle shell 11 at positions corresponding to the frame 2, and the middle shell 11 and the frame 2 may be fixed together by welding the holes.

[0065] Alternatively, the frame 2 may be press-fitted from the upper side to the lower side (from the U side to the L side) of the middle shell 11 in the axial direction Y to fix the frame 2 to the middle shell 11. However, the method of fixing the frame 2 to the middle shell 11 is not limited to these.

[0066] The fixed scroll 31 is fixed in such a manner that the second outer peripheral surface 31G1 of the fixed scroll 31 contacts the first inner peripheral surface 11N1 of the middle shell 11, the lower end surface 31F2 of the protruding portion 31GG of the fixed scroll 31 contacts the upper end surface 11F1 of the middle shell 11, and the upper end surface 31F3 of the protruding portion 31GG of the fixed scroll 31 contacts the first step surface 12F4 of the first step portion 12NN of the upper shell 12. Therefore, the fixed scroll 31 does not contact the third step surface 11F11 and the third inner peripheral surface 11N11 of the third step portion 11NM of the middle shell 11.

[0067] As a fixing method, for example, the outer diameter of the second outer peripheral surface 31G1 of the fixed scroll 31 is formed larger than the inner diameter of the first inner peripheral surface 11N1 of the middle shell 11, and the fixed scroll 31 is shrink-fitted or chill-fitted. Alternatively, the middle shell 11 and the fixed scroll 31 may be fixed by penetration welding using a laser or the like.

[0068] Alternatively, the fixed scroll 31 may be press-fitted from the upper side to the lower side (from the U side to the L side) in the axial direction Y of the middle shell 11 to fix the fixed scroll 31 to the middle shell 11. However, the method for fixing the fixed scroll 31 to the middle shell 11 is not limited to these.

[0069] Furthermore, the following two surfaces are preferably formed by machining. Forming them by machining allows for high-precision control, allowing the gap between the orbiting scroll 32 and the fixed scroll 31 to be maintained small, improving the performance of the scroll compressor 100. A third inner circumferential surface 11N11 having an inner diameter smaller than the inner diameter of the first inner circumferential surface 11N1 of the middle shell 11 and the outer diameter of the second outer circumferential surface 31G1 of the fixed scroll 31. A third step surface 11F11 that is perpendicular to the third inner circumferential surface 11N11 of the middle shell 11, parallel to the upper end surface 11F1 of the middle shell 11, and sandwiched between the first inner circumferential surface 11N1 of the middle shell 11 and the third inner circumferential surface 11N11 of the middle shell 11.

[0070] As described above, when the frame 2 and the fixed scroll 31 are fixed to the middle shell 11 by shrink fitting or cold fitting, the inner diameter H1 (see FIG. 2) of the first inner circumferential surface 11N1 of the middle shell 11 that fixes the fixed scroll 31 is larger than the inner diameter H11 of the third inner circumferential surface 11N11 of the middle shell 11 that fixes the frame 2. Therefore, when heating or cooling, the fixed scroll 31 can be shrink-fitted or cold-fitted with a smaller temperature difference than the frame 2, and the fixed scroll 31 can be fixed to the middle shell 11 with less energy.

[0071] Alternatively, when the frame 2 and the fixed scroll 31 are fixed to the middle shell 11 by press-fitting, the frame 2 and the fixed scroll 31 are fixed using the third inner surface 11N11 of the middle shell 11 and the first inner surface 11N1 which is different from the third inner surface 11N11, so the fixed scroll 31 can be fixed more firmly to the middle shell 11, and airtightness is improved because there is less damage due to sliding.

[0072] In addition to the above-described embodiments, it is preferable to chamfer or round the following corners to avoid interference: A corner at the boundary between the third step surface 11F11 of the third step portion 11NM of the middle shell 11 and the third inner peripheral surface 11N11 of the middle shell 11.

[0073] Furthermore, it is preferable to form the following three surfaces by machining. Forming them by machining allows for high-precision control, and the gap between the orbiting scroll 32 and the fixed scroll 31 can be maintained small, improving the performance of the scroll compressor 100. - An upper end surface 11F1 at the upper end of the axial direction Y of the middle shell 11 - A first inner circumferential surface 11N1 perpendicular to the upper end surface 11F1 of the middle shell 11 - A second step surface 11F0 of the second step portion 11NN of the middle shell 11

[0074] The scroll compressor of the third embodiment configured as described above not only achieves the same effects as the above-described embodiments, but also: the middle shell has a second step portion whose inner diameter is smaller axially below the first inner circumferential surface of the middle shell, and a third step portion whose inner diameter is smaller axially above the second step portion on the inner circumferential surface between the fixed scroll and the frame; and the frame is fixed to the second step surface of the second step portion of the middle shell and to the third inner circumferential surface of the middle shell axially above the second step portion and below the third step portion. Therefore, when the frame and the fixed scroll are fixed to the middle shell by shrink fitting or cold fitting, the inner diameter of the first inner circumferential surface of the middle shell that secures the fixed scroll is larger than the inner diameter of the third inner circumferential surface of the middle shell that secures the frame. Therefore, when heating or cooling is performed, the fixed scroll can be shrink fitted or cold fitted with a smaller temperature difference than the frame, and the fixed scroll can be fixed to the middle shell with less energy.

[0075] Alternatively, when the frame and fixed scroll are fixed to the middle shell by press fitting, the frame and fixed scroll are fixed using the third inner peripheral surface of the middle shell and the first inner peripheral surface which is different from the third inner peripheral surface, so the fixed scroll can be fixed more firmly to the middle shell, and airtightness is improved as there is less damage due to sliding.

[0076] Fourth Embodiment Fig. 8 is a partial cross-sectional view showing the configuration of a scroll compressor according to a fourth embodiment. Fig. 9 is a partial cross-sectional view showing the configuration of the scroll compressor shown in Fig. 8. Fig. 10 is a partial cross-sectional view showing the configuration of a scroll compressor of a comparative example. A scroll compressor 100 according to the fourth embodiment will be described with reference to Fig. 8. In Fig. 8, parts that are the same as those in the above-described embodiments are given the same reference numerals and omitted. Furthermore, in the fourth embodiment, description of parts that are the same as those in the above-described embodiments will be omitted as appropriate, and the description will focus on parts that are different from those in the above-described embodiments.

[0077] 8, the inner diameter H2 of the second inner peripheral surface 12N3 of the upper shell 12 is formed to be equal to or larger than the inner diameter H3 of the first inner peripheral surface 11N1 of the middle shell 11. Note that the inner diameters H2 and H3 are shown in FIG.

[0078] 9 , when the welded portion 99 contracts, the fixed scroll 31 receives a force F1 mainly in the direction from the top to the bottom (from the U side to the L side) in the axial direction Y via the first step surface 12F4 of the upper shell 12. The fixed scroll 31 receives a force F2 in the direction from the top to the bottom (from the U side to the L side) in the axial direction Y in the same manner as described above, in the contact area between the first step surface 12F4 of the upper shell 12 and the upper end surface 31F3 of the protrusion 31GG of the fixed scroll 31.

[0079] The lower side (L side) of this contact area in the axial direction Y is supported by the upper end surface 11F1 of the middle shell 11. Therefore, as shown in Fig. 9, by forming the inner diameter H2 of the second inner circumferential surface 12N3 of the upper shell 12 to be the same as the inner diameter H3 of the first inner circumferential surface 11N1 of the middle shell 11, the point receiving the force from the upper shell 12 can be brought closer to the support point of the middle shell 11, and deformation of the fixed scroll 31 can be suppressed, compared to the comparative example shown in Fig. 10.

[0080] The scroll compressor of embodiment 4 configured as described above has the same effects as the above embodiments, and the inner diameter of the second inner peripheral surface axially above the first step portion of the upper shell is formed to be the same as or larger than the inner diameter of the first inner peripheral surface of the middle shell, so that the point receiving force from the upper shell can be brought closer to the support point of the middle shell, thereby suppressing deformation of the fixed scroll.

[0081] Fifth Embodiment Fig. 12 is a partial cross-sectional view showing the configuration of a scroll compressor according to a fifth embodiment. Fig. 13 is a diagram showing the relationship between the formation positions of welds in a scroll compressor according to the fifth embodiment and the deformation amounts of the fixed scroll and the frame. A scroll compressor 100 according to the fifth embodiment will be described with reference to Fig. 12. In Fig. 12, parts that are the same as those in the above-described embodiments are given the same reference numerals and omitted. Furthermore, in the fifth embodiment, description of parts that are the same as those in the above-described embodiments will be omitted as appropriate, and the description will focus on parts that are different from those in the above-described embodiments.

[0082] In the fifth embodiment, the position where the welded portion 99 is formed will be described. As shown in Fig. 12, a first distance T1 is defined as the distance from the upper end surface 31F3 of the fixed scroll 31, which is in contact with the first step surface 12F4 of the upper shell 12, to the lower end surface 12F5 of the upper shell 12, where the welded portion 99 is formed. A second distance T2 is defined as the distance from the lower end surface 12F5 of the upper shell 12, where the welded portion 99 is formed, to the upper end surface 2F0 of the frame 2. The ratio between the first distance T1 and the second distance T2 is determined based on the rigidity of the fixed scroll 31 and the rigidity of the frame 2.

[0083] 13 , the horizontal axis indicates the position where the weld 99 is formed from the position of the upper end surface 31F3 of the protrusion 31GG of the fixed scroll 31 in the axial direction Y to the position of the upper end surface 2F0 of the frame 2. The vertical axis indicates the amount of deformation of the fixed scroll 31 and the amount of deformation of the frame 2. As can be seen from the figure, as the first distance T1 increases from the position where the weld 99 is formed, the amount of deformation of the fixed scroll 31 decreases, while the amount of deformation of the frame 2 increases.

[0084] Therefore, by determining the ratio of the first distance T1 to the second distance T2 in consideration of the rigidity of the fixed scroll 31 and the rigidity of the frame 2, it is possible to determine the position at which the weld 99 is formed that can minimize the amount of deformation of the fixed scroll 31 and the frame 2. The ratio of the first distance T1 to the second distance T2 can be determined, for example, by setting the ratio of the first distance T1 to the second distance T2 to the inverse ratio of the rigidity so that the amount of deformation of the fixed scroll 31 and the amount of deformation of the frame 2 are the same (for example, the position of intersection Q in FIG. 13 ). Note that this is just one example, and the position at which the weld 99 is formed can be appropriately set based on the rigidity of the fixed scroll 31 and the rigidity of the frame 2 depending on the performance required of the scroll compressor 100.

[0085] According to the scroll compressor of embodiment 5 configured as described above, the same effects as those of the above embodiments are achieved, and the first distance from the upper end surface of the fixed scroll to the lower end surface of the upper shell and the second distance from the axial upper end surface of the frame to the lower end surface of the upper shell are determined based on the rigidity of the frame and the rigidity of the fixed scroll, and the position of the weld is determined, so that the formation position of the weld can be determined so as to optimally suppress the deformation amount of the fixed scroll and the deformation amount of the frame.

[0086] Sixth Embodiment Fig. 14 is a partial cross-sectional view showing the configuration of a scroll compressor according to a sixth embodiment. Fig. 15 is an enlarged view of the portion of the scroll compressor shown in Fig. 14 surrounded by dotted line S3. A scroll compressor 100 according to the sixth embodiment will be described with reference to Figs. 14 and 15. In Figs. 14 and 15, parts that are the same as those in the above-described embodiments are given the same reference numerals and omitted. In the sixth embodiment, description of parts that are the same as those in the above-described embodiments will be omitted as appropriate, and the description will focus on parts that are different from those in the above-described embodiments.

[0087] 14 and 15 , the middle shell 11 has a fourth step portion 11NP whose outer diameter increases downward in the axial direction Y from the first outer peripheral surface 11G1 of the middle shell 11. The outer periphery of the middle shell 11 below the fourth step portion 11NP of the middle shell 11 in the axial direction Y is a second outer peripheral surface 11G2. The lower end surface 12F5 in the axial direction Y of the upper shell 12 is disposed opposite the fourth step surface 11F2 of the fourth step portion 11NP of the middle shell 11 with a gap P (see FIG. 15 ) between them.

[0088] This gap P occurs because the first step surface 12F4 of the upper shell 12 and the upper end surface 31F3 of the fixed scroll 31 are in contact with each other, making it difficult to bring the lower end surface 12F5 of the upper shell 12 into contact with the fourth step surface 11F2 of the middle shell. A weld 99 (see FIG. 15 ) is formed in this gap P. Low-strain welding, such as laser welding, can be used to form the weld 99. However, it is also possible not to form the weld 99.

[0089] 14 and 15, the gap P is exaggerated to make it clearer, but is formed to be as narrow as possible, and the outer peripheral surface 12G1 of the upper shell 12 and the second outer peripheral surface 11G2 below the fourth step portion 11NP of the middle shell 11 in the axial direction Y are formed substantially continuously. The upper shell 12 has a tubular portion 121 that opens toward the middle shell 11, and a bottom portion 122 that connects to the tubular portion 121 on the opposite side of the middle shell 11 in the axial direction Y, and has a heating mark 200 on the upper side of the tubular portion 121 in the axial direction Y.

[0090] The reason why a heat mark 200 is formed by heating this portion will now be explained. As shown in FIG. 15 , when a weld 99 is formed in the gap P between the lower end surface 12F5 of the upper shell 12 and the fourth step surface 11F2 of the middle shell, the weld 99 is formed locally across the entire thickness of the upper shell 12 and the middle shell 11. Therefore, the upper shell 12 and the middle shell 11 undergo localized contraction deformation due to compression near the weld 99, causing the upper shell 12 and the middle shell 11 to bend laterally around the weld 99 (deformation as shown by the dotted line in FIG. 15 ). This is a state in which angular deformation occurs in the upper shell 12 and the middle shell 11. To suppress this angular deformation, the upper portion of the tubular portion 121 of the upper shell 12 is heated to suppress this deformation. As a result, a heat mark 200 remains in the corresponding portion.

[0091] The scroll compressor of embodiment 5 configured as described above achieves the same effects as the above embodiments, and in addition, the middle shell has a fourth step portion whose outer diameter is larger axially downward than the first outer peripheral surface of the middle shell, and the axial lower end surface of the upper shell is positioned opposite the fourth step surface of the fourth step portion of the middle shell via a gap, thereby ensuring reliable contact between the upper shell and the fixed scroll and increasing the fixing strength of the fixed scroll.

[0092] Furthermore, the upper shell has a tubular portion that opens toward the middle shell and a bottom portion that connects to the tubular portion on the axially opposite side of the middle shell, and the tubular portion has heating marks on the axially upper side, so that angular deformation of the upper shell and middle shell can be suppressed.

[0093] In the above, the terms "vertical," "parallel," or "same" refer to "vertical," "parallel," or "same" as commonly understood by those skilled in the art when manufacturing the scroll compressor 100, and include "approximately vertical," "approximately parallel," or "approximately the same" within the scope commonly understood by those skilled in the art.

[0094] Although various exemplary embodiments and examples are described in this disclosure, the various features, aspects, and functions described in one or more embodiments are not limited to the application of a particular embodiment, but may be applied to the embodiments alone or in various combinations. Therefore, countless modifications not illustrated are contemplated within the scope of the disclosed technology. For example, this includes cases where at least one component is modified, added, or omitted, and even cases where at least one component is extracted and combined with components of another embodiment.

[0095] Various aspects of the present disclosure are summarized below as appendices.

[0096] (Supplementary Note 1) A scroll compressor comprising: an orbiting scroll; a frame that slidably holds the orbiting scroll; a fixed scroll that forms a compression chamber together with the orbiting scroll; a middle shell that houses the frame, the orbiting scroll, and the fixed scroll; and an upper shell that seals the middle shell above the fixed scroll, wherein the fixed scroll has a protruding portion that protrudes radially outward between its outer peripheral surfaces in the axial direction and has a first outer peripheral surface, and a second outer peripheral surface axially below the protruding portion, wherein the upper shell has, on its inner peripheral surface facing the middle shell, a first step portion whose inner diameter is larger on the axially lower side, wherein the fixed scroll is fixed such that an upper axial end surface of the protruding portion abuts a first step surface of the first step portion of the upper shell and a lower axial end surface of the protruding portion abuts an upper axial end surface of the middle shell, and wherein the second outer peripheral surface of the fixed scroll is formed in contact with a first inner peripheral surface on the axial upper side of the middle shell. (Supplementary Note 2) The scroll compressor according to Supplementary Note 1, wherein an outer diameter of the first outer peripheral surface of the fixed scroll is smaller than an inner diameter of a first inner peripheral surface below the first step portion of the upper shell. (Supplementary Note 3) The scroll compressor according to Supplementary Note 1 or Supplementary Note 2, wherein the middle shell has a second step portion whose inner diameter is smaller axially downward than the first inner peripheral surface of the middle shell, and the frame is fixed in contact with a second step surface of the second step portion of the middle shell and the first inner peripheral surface of the middle shell. (Supplementary Note 4) The scroll compressor according to Supplementary Note 1 or Supplementary Note 2, wherein the middle shell has a second step portion whose inner diameter is smaller axially below the first inner circumferential surface of the middle shell, and a third step portion whose inner diameter is smaller axially above the second step portion on an inner circumferential surface between the fixed scroll and the frame, and the frame is fixed in contact with a second step surface of the second step portion of the middle shell and a third inner circumferential surface of the middle shell that is axially above the second step portion and axially below the third step portion.(Supplementary Note 5) The scroll compressor according to any one of Supplementary Notes 1 to 4, wherein the second outer peripheral surface of the fixed scroll is formed continuously over 360 degrees in the circumferential direction, and the second outer peripheral surface of the fixed scroll and the first inner peripheral surface of the middle shell are fixed by shrink fitting. (Supplementary Note 6) The scroll compressor according to any one of Supplementary Notes 1 to 5, wherein a welded portion is formed by welding a lower end surface of the axial direction of the upper shell to the outer peripheral surface of the middle shell at a position axially lower than an upper end surface of the middle shell. (Supplementary Note 7) The scroll compressor according to any one of Supplementary Notes 1 to 6, wherein an inner diameter of a second inner peripheral surface axially above the first step portion of the upper shell is formed to be the same as an inner diameter of the first inner peripheral surface of the middle shell. (Supplementary Note 8) The scroll compressor according to any one of Supplementary Notes 1 to 7, wherein a first groove portion recessed in the radial direction is formed in the first outer peripheral surface of the fixed scroll. (Supplementary Note 9) A scroll compressor according to any one of Supplementary Notes 1 to 8, wherein a second groove portion recessed axially upward is formed on the axial lower end surface of the fixed scroll radially outward of the scroll wrap of the scroll compressor.

[0097] 1 Shell, 100 Scroll compressor, 11 Middle shell, 11F0 Second step surface, 11F1 Upper end surface, 11F2 Fourth step surface, 11F11 Third step surface, 11G1 First outer peripheral surface, 11G2 Second outer peripheral surface, 11N0 Second inner peripheral surface, 11N1 First inner peripheral surface, 11NN Second step portion, 11NP Fourth step portion, 12 Upper shell, 12U Recess, 121 Cylindrical portion, 122 Bottom, 12N2 First inner peripheral surface, 12NN First step portion, 12F4 First step surface, 12F5 Lower end surface, 12G1 Outer peripheral surface, 12N3 Second inner peripheral surface, 13 Lower shell, 15 Discharge pipe, 2 Frame, 2F1 Lower end surface, 2G0 Outer peripheral surface, 20 Bearing, 201 Welded portion, 202 Seal portion, 31 fixed scroll, 31F3 upper end surface, 31F2 lower end surface, 31F4 lower end surface, 31G1 second outer peripheral surface, 31G2 first outer peripheral surface, 31GA first protrusion, 31GB second protrusion, 31GC third protrusion, 31GD fourth protrusion, 31GG protrusion, 32 orbiting scroll, 34 compression chamber, 311 scroll wrap, 4 drive portion, 50 subframe, 6 crankshaft, 62 eccentric shaft portion, 99 welded portion, H1 inner diameter, H2 inner diameter, H3 inner diameter, H4 inner diameter, H11 inner diameter, T1 first distance, T2 second distance, P gap, W1 outer diameter, W2 outer diameter, Y axial direction, X radial direction.

Claims

1. A swing scroll; A frame that slidably holds the orbiting scroll; a fixed scroll forming a compression chamber together with the orbiting scroll; a middle shell that houses the frame, the orbiting scroll, and the fixed scroll; an upper shell that seals an upper side of the fixed scroll of the middle shell, the fixed scroll has a protruding portion protruding radially outwardly between the outer circumferential surfaces in the axial direction and having a first outer circumferential surface, and a second outer circumferential surface below the protruding portion in the axial direction, The upper shell has an inner circumferential surface on the middle shell side, the inner diameter of which is increased on a lower side in the axial direction, and a first step portion is provided on the inner circumferential surface on the middle shell side. The fixed scroll is fixed such that an axial upper end surface of the protruding portion is in contact with a first step surface of the first step portion of the upper shell, and an axial lower end surface of the protruding portion is in contact with an axial upper end surface of the middle shell, The second outer peripheral surface of the fixed scroll is formed in contact with a first inner peripheral surface of the middle shell on an upper side in the axial direction, a first inner circumferential surface of the first step portion of the upper shell that is in contact with a first outer circumferential surface of the middle shell that is in the axial direction;

2. The scroll compressor according to claim 1 , wherein an outer diameter of the first outer peripheral surface of the fixed scroll is smaller than an inner diameter of the first inner peripheral surface of the upper shell.

3. The first inner circumferential surface of the upper shell has a recess that is recessed radially outward only at a position facing the first outer circumferential surface of the fixed scroll, 3. The scroll compressor according to claim 1, wherein a lower end surface of the protruding portion in the axial direction is in contact with and fixed to an entire upper end surface of the middle shell in the axial direction.

4. the middle shell has a second step portion whose inner diameter is smaller axially downward than the first inner circumferential surface of the middle shell, The scroll compressor according to claim 1 or 2, wherein the frame is fixed in contact with a second step surface of the second step portion of the middle shell and the first inner circumferential surface of the middle shell.

5. the middle shell has a second step portion, the inner diameter of which is smaller on an axially lower side than the first inner peripheral surface of the middle shell, and a third step portion, the inner diameter of which is smaller on an inner peripheral surface between the fixed scroll and the frame and axially above the second step portion; 3. The scroll compressor according to claim 1, wherein the frame is fixed in contact with a second step surface of the second step portion of the middle shell and a third inner circumferential surface that is axially above the second step portion of the middle shell and axially below the third step portion of the middle shell.

6. The second outer peripheral surface of the fixed scroll is formed continuously over 360 degrees in the circumferential direction, 3. The scroll compressor according to claim 1, wherein the second outer peripheral surface of the fixed scroll and the first inner peripheral surface of the middle shell are fixed to each other by shrink fitting.

7. 3. The scroll compressor according to claim 1, wherein an inner diameter of a second inner circumferential surface of the upper shell that is axially above the first step portion is formed to be the same as an inner diameter of the first inner circumferential surface of the middle shell.

8. The first outer peripheral surface of the fixed scroll is 3. The scroll compressor according to claim 1, further comprising a first groove portion recessed in a radial direction.

9. The fixed scroll has a lower end surface in the axial direction, A scroll wrap of the scroll compressor is provided radially outward.

3. The scroll compressor according to claim 1, further comprising a second groove portion recessed upward in the axial direction.

10. The middle shell has a fourth step portion whose outer diameter is larger axially downward than the first outer circumferential surface of the middle shell, 3. The scroll compressor according to claim 1, wherein an axial lower end surface of the upper shell is disposed opposite a fourth step surface of the fourth step portion of the middle shell with a gap therebetween.

11. 3. The scroll compressor according to claim 1, wherein a welded portion is formed between a lower end surface of the upper shell and the middle shell in the axial direction, the lower end surface of the upper shell being located axially below an upper end surface of the middle shell.

12. Based on the rigidity of the frame and the rigidity of the fixed scroll, a first distance from the top end surface of the fixed scroll to the bottom end surface of the upper shell; and 12. The scroll compressor according to claim 11, wherein a second distance in the axial direction from an upper end surface of the frame to the lower end surface of the upper shell is determined, and a position of the weld is determined.

13. The upper shell has a cylindrical portion that opens toward the middle shell side and a bottom portion that is connected to the cylindrical portion on the axially opposite side to the middle shell side, The scroll compressor according to claim 11, wherein an axially upper side of the cylindrical portion has a heating mark.