Scroll Compressor

Abstract

To provide a scroll compressor capable of improving compression efficiency in a constrained physique.SOLUTION: In a scroll compressor, a revolving-side spiral wall 32b has a shape that draws an involute curve and has a plate thickness. The revolving-side spiral wall 32b has a non-linear part R2 as a thin wall part having a thickness thinner than its surroundings. The non-linear part R2 as the thin wall part includes a portion at an expansion angle obtained by subtracting 360° from a maximum expansion angle.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a scroll compressor. [Background technology]

[0002] A scroll-type compressor has a fixed scroll fixed in a housing and an orbiting scroll that revolves around the fixed scroll (see, for example, Patent Document 1). The fixed scroll has a fixed base plate and a fixed spiral wall standing upright from the fixed base plate, and the orbiting scroll has a orbiting base plate and a orbiting spiral wall standing upright from the orbiting base plate. The fixed spiral wall and the orbiting spiral wall are meshed with each other to define a compression chamber that reduces in volume based on the orbital motion of the orbiting scroll to compress the fluid. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-193582 A Summary of the Invention [Problem to be solved by the invention]

[0004] The size of a scroll compressor needs to be appropriate for the location where it is installed. This imposes restrictions on the size of the scroll compressor. On the other hand, it is desirable to improve the performance of a scroll compressor by increasing the amount of fluid that can be trapped in the compression chamber. In other words, it is desirable to improve the compression efficiency of a scroll compressor within a restricted size. [Means for solving the problem]

[0005] A scroll-type compressor for solving the above-mentioned problems includes a fixed scroll having a fixed-side base plate and a fixed-side spiral wall standing from the fixed-side base plate, a disk-shaped orbiting-side base plate facing the fixed-side base plate, and an orbiting scroll having an orbiting-side spiral wall standing from the orbiting-side base plate towards the fixed-side base plate and meshing with the fixed-side spiral wall, and the orbiting scroll orbits to compress a fluid in a compression chamber defined by the fixed scroll and the orbiting scroll, wherein the orbiting-side spiral wall has a shape that describes an involute curve and has a plate thickness, the orbiting-side spiral wall has a thin-walled portion that is thinner than a surrounding area, and the thin-walled portion includes a portion at the extension angle that is 360° subtracted from a maximum extension angle.

[0006] The comparative example is an orbiting scroll that does not include a thin portion in the orbiting-side spiral wall. The diameter of the orbiting-side substrate of the comparative example is the same as the diameter of the orbiting-side substrate of the present application. The orbiting scroll having a thin portion in the orbiting-side spiral wall can extend the position of the end of the involute curve, where the maximum value of the extension angle is located, in the circumferential direction of the orbiting-side substrate more than the comparative example without protruding from the outer edge of the orbiting-side substrate. As a result, the amount of fluid trapped in the compression chamber can be increased compared to the comparative example. Therefore, according to the orbiting scroll having a thin portion, the number of turns of the orbiting-side spiral wall can be increased without increasing the diameter of the orbiting-side substrate, and the compression efficiency of the scroll compressor can be improved.

[0007] In a scroll-type compressor, the orbiting-side spiral wall may have a linear portion where the plate thickness decreases linearly as the extension angle increases, and a nonlinear portion where the plate thickness changes nonlinearly as the extension angle increases, the thin portion being the nonlinear portion, and the plate thickness may be minimal in the nonlinear portion.

[0008] According to this, the scroll compressor has a linear portion around the nonlinear portion, in which the change in plate thickness with respect to the extension angle is the same as that of a general orbiting spiral wall. By having the nonlinear portion including the thin portion, the number of turns of the orbiting spiral wall can be increased without degrading the performance compared to a general scroll compressor.

[0009] In the scroll compressor, the wall thickness of the orbiting-side volute wall may be minimal in the nonlinear portion at a portion of the extension angle that is 360° or more less than the maximum extension angle.

[0010] According to this, the nonlinear portion can be formed from an inflection angle smaller than a position obtained by subtracting 360° or more from the maximum value of the inflection angle of the orbiting-side spiral wall. Effect of the Invention

[0011] According to the present invention, compression efficiency can be improved within a restricted body size. [Brief description of the drawings]

[0012] [Figure 1] 1 is a cross-sectional view showing a scroll compressor according to an embodiment. [Diagram 2] FIG. [Diagram 3] FIG. 4 is a diagram showing an orbiting scroll of a comparative example. [Figure 4] FIG. 4 is a diagram showing an orbiting scroll of a comparative example. [Diagram 5] 1 is a graph showing the relationship between plate thickness and expansion angle. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, a scroll type compressor according to one embodiment will be described with reference to Figures 1 to 5. An example of an application in which the scroll type compressor is mounted is a vehicle. <Housing> As shown in Fig. 1, the scroll compressor 10 is an electric scroll compressor. The scroll compressor 10 includes a housing 11. The housing 11 has a suction port 11a through which a fluid is drawn and a discharge port 11b through which the fluid is discharged. The housing 11 has a generally cylindrical shape.

[0014] The housing 11 has a first part 12 and a second part 13, each having a cylindrical shape with a bottom. The first part 12 and the second part 13 are assembled with their open ends butted against each other. The suction port 11a is provided in the first part 12. The discharge port 11b is provided in the second part 13.

[0015] The scroll compressor 10 includes a rotating shaft 14, a compression section 15, and an electric motor 16. The rotating shaft 14, the compression section 15, and the electric motor 16 are accommodated in a housing 11.

[0016] <Rotation axis> The rotating shaft 14 is accommodated in the housing 11 in a rotatable state. A support member 21 that supports the rotating shaft 14 is provided in the housing 11. The support member 21 is fixed to the housing 11, for example, at a position between the compression section 15 and the electric motor 16. An insertion hole 23 is formed in the support member 21. A first bearing 22 is provided in the insertion hole 23. The rotating shaft 14 is inserted into the insertion hole 23. The support member 21 and the bottom portion 12b of the first part 12 face each other. A cylindrical boss 24 protrudes from the bottom portion 12b. A second bearing 25 is provided inside the boss 24. The rotating shaft 14 is supported by the housing 11 in a rotatable state by both the bearings 22, 25.

[0017] <Electric motor> The electric motor 16 is disposed on the suction port 11a side within the housing 11. The electric motor 16 rotates the rotary shaft 14. The electric motor 16 drives the compression section 15. The electric motor 16 includes a rotor 51 that rotates integrally with the rotary shaft 14, and a stator 52 that surrounds the rotor 51. The rotor 51 is connected to the rotary shaft 14. The stator 52 is fixed to an inner peripheral surface of the first part 12 of the housing 11. The stator 52 includes a stator core 53 that faces the cylindrical rotor 51 in the radial direction, and a coil 54 wound around the stator core 53.

[0018] <Compression section> The compression section 15 is disposed closer to the discharge port 11b than the electric motor 16 is within the housing 11. The compression section 15 compresses the fluid sucked from the suction port 11a and discharges the fluid from the discharge port 11b. The compression section 15 includes a fixed scroll 31 and a rotating scroll 32. The fixed scroll 31 is fixed to the housing 11. The rotating scroll 32 rotates relative to the fixed scroll 31. The rotating scroll 32 is capable of revolving relative to the fixed scroll 31.

[0019] The fixed scroll 31 has a fixed-side substrate 31a, a fixed-side spiral wall 31b, and a partition wall 31c. The fixed-side substrate 31a is disk-shaped and is arranged coaxially with the rotary shaft 14. The fixed-side spiral wall 31b stands upright from the fixed-side substrate 31a. The partition wall 31c stands upright from the outer periphery of the fixed-side substrate 31a. The partition wall 31c is arranged on the outer periphery side of the fixed-side spiral wall 31b in the radial direction of the fixed-side substrate 31a.

[0020] The orbiting scroll 32 has an orbiting-side base plate 32a and an orbiting-side spiral wall 32b. The orbiting-side base plate 32a is disk-shaped and faces the fixed-side base plate 31a. The orbiting-side spiral wall 32b stands upright from the orbiting-side base plate 32a toward the fixed-side base plate 31a.

[0021] The orbiting scroll 32 is accommodated in a space 29 defined within the housing 11. The space 29 is defined by the shaft support member 21, a fixed side base plate 31a, and a partition wall 31c. The orbiting scroll 32 orbits within the space 29.

[0022] The fixed scroll 31 and the orbiting scroll 32 mesh with each other. More specifically, the fixed-side spiral wall 31b and the orbiting-side spiral wall 32b mesh with each other. The tip surface of the fixed-side spiral wall 31b contacts the orbiting-side base plate 32a, and the tip surface of the orbiting-side spiral wall 32b contacts the fixed-side base plate 31a. The fixed scroll 31 and the orbiting scroll 32 define a compression chamber 33 that compresses a fluid. In the scroll compressor 10, a plurality of compression chambers 33 are formed simultaneously.

[0023] The compression chamber 33 is formed with two chambers: a first compression chamber formed by the inner peripheral side of the fixed side spiral wall 31b and the outer peripheral side of the orbiting side spiral wall 32b, and a second compression chamber formed by the outer peripheral side of the fixed side spiral wall 31b and the inner peripheral side of the orbiting side spiral wall 32b.

[0024] The radius of the circular path that the orbiting scroll 32 describes when it revolves is defined as the orbital radius. The orbiting-side spiral wall 32b is provided so as not to protrude from the outer peripheral edge of the orbiting-side base plate 32a. Therefore, the orbital radius of the orbiting scroll 32 is determined by the diameter of the orbiting-side base plate 32a. In addition, since the orbiting scroll 32 revolves within the space 29, it can be said that the diameter of the orbiting-side base plate 32a is determined by the size of the space 29.

[0025] A suction passage 34 is formed in the shaft support member 21. The suction passage 34 is a passage for sucking fluid into the compression chamber 33. The orbiting scroll 32 is configured to revolve with the rotation of the rotary shaft 14. In detail, a part of the rotary shaft 14 protrudes toward the compression section 15 through the insertion hole 23 of the shaft support member 21. An eccentric shaft 35 is provided at a position eccentric to the axis L of the rotary shaft 14 on the end face of the rotary shaft 14 on the compression section 15 side. A bush 36 is provided on the eccentric shaft 35. The bush 36 and the orbiting side base plate 32a are connected via a bearing 37.

[0026] The scroll compressor 10 includes a rotation restricting portion 38. The rotation restricting portion 38 allows the orbital motion of the orbiting scroll 32, while restricting the rotation of the orbiting scroll 32. A plurality of rotation restricting portions 38 are provided. When the rotating shaft 14 rotates in a predetermined forward direction, the orbiting scroll 32 revolves in the forward direction. The orbiting scroll 32 revolves in the forward direction around the axis of the fixed scroll 31, i.e., the axis L of the rotating shaft 14. As a result, the volumes of the first and second compression chambers are reduced, and the fluid sucked into the first and second compression chambers through the suction passage 34 is compressed. The compressed fluid is discharged from a discharge port 41 provided in the fixed side base plate 31a. The fluid discharged from the discharge port 41 is discharged from the discharge port 11b. A discharge valve 42 covering the discharge port 41 is provided in the fixed side base plate 31a. The fluid compressed in the compression chamber 33 pushes aside the discharge valve 42 and is discharged from the discharge port 41 .

[0027] <Inverter> The scroll compressor 10 includes an inverter 55. The inverter 55 is a drive circuit that drives the electric motor 16. The inverter 55 is housed in a cylindrical cover member 56 attached to the bottom 12b of the first part 12 of the housing 11. The inverter 55 and the coil 54 are electrically connected to each other.

[0028] <Details of the rotating scroll> 2 shows only the orbiting-side substrate 32a and the orbiting-side spiral wall 32b of the orbiting scroll 32. The orbiting-side spiral wall 32b is spiral-shaped extending from a first end E located on the center side of the spiral to a second end S located on the outer periphery side of the spiral.

[0029] In the orbiting-side spiral wall 32b, an end portion including the first end E is formed in an arc shape. The orbiting-side spiral wall 32b has a shape in which an involute curve has a plate thickness except for a part. The outer peripheral wall 321 and the inner peripheral wall 322 of the orbiting-side spiral wall 32b are formed by an involute curve except for a part.

[0030] An involute curve is a plane curve formed by the path traced by the tip of a normal line set to a base circle when the normal line is moved so as to always be tangent to the base circle without slipping. An involute curve is also called an involute line, and is also the path traced by the end point of a thread wound around a base circle when the thread is unstretched so as not to loosen. The involute angle is the angle formed between the base circle and the thread when the thread is unstretched around the center of the base circle. In the orbiting-side spiral wall 32b, the first end E corresponds to the start of the involute curve, and the second end S corresponds to the end of the involute curve.

[0031] The orbiting-side spiral wall 32b has an arc portion F that continues from the start of the involute curve. The arc portion F is an arc that continues to a first end E of the orbiting-side spiral wall 32b. The involution angle [°] is the distance from the first end E, where the involute curve of the orbiting-side spiral wall 32b begins, to the second end S, where the involute curve ends, along the orbiting-side spiral wall 32b. The minimum involution angle is "0" at the first end E, that is, zero. The involution angle increases as it moves from the first end E toward the second end S along the orbiting-side spiral wall 32b. If the number of turns of the fixed-side spiral wall 31b and the orbiting-side spiral wall 32b is about two and a half turns, the maximum involution angle is about 900°.

[0032] <Thickness of the volute wall on the rotating side> The dimension between the outer peripheral wall 321 and the inner peripheral wall 322 of the orbiting-side spiral wall 32b is defined as the plate thickness W [mm]. As described above, the outer peripheral wall 321 and the inner peripheral wall 322 of the orbiting-side spiral wall 32b are formed by involute curves except for a part. More specifically, the inner peripheral wall 322 is formed by an involute curve that is offset from the involute curve that forms the outer peripheral wall 321 toward the inner peripheral side to such an extent that it does not interfere with the fixed-side spiral wall 31b during orbit.

[0033] As shown in FIGS. 2 and 5, as the extension angle increases from the minimum value along the arc portion F, the plate thickness W of the orbiting-side spiral wall 32b increases rapidly to a maximum value, and then decreases rapidly.

[0034] The orbiting-side spiral wall 32b includes a linear portion R1 and a nonlinear portion R2 defined by the relationship between the expansion angle and the plate thickness W. The orbiting-side spiral wall 32b also includes the linear portion R1 and the nonlinear portion R2 between the minimum and maximum values ​​of the expansion angle. In detail, the orbiting-side spiral wall 32b includes two linear portions R1 and one nonlinear portion R2 in a portion where the expansion angle increases more than the arc portion F.

[0035] The linear portion R1 is a part between the minimum and maximum values ​​of the inflection angle. The linear portion R1 is a portion where the plate thickness W decreases linearly as the inflection angle increases. Here, the ratio of the decrease in the plate thickness W to the increase in the inflection angle is defined as the "thickness change rate." Each of the two linear portions R1 is a portion where the thickness change rate is constant. In each of the two linear portions R1, the plate thickness W of the orbiting-side spiral wall 32b becomes linearly thinner as the inflection angle increases. Note that the inflection angle located at the boundary between the linear portion R1 with the smaller inflection angle and the arc portion F is defined as the "first inflection angle G1." The two linear portions R1 are provided on both sides of the nonlinear portion R2 described below.

[0036] The nonlinear portion R2 is a part between the minimum and maximum values ​​of the inflection angle. The nonlinear portion R2 is a portion where the plate thickness W changes nonlinearly with an increase in the inflection angle, and is a portion including a minimum value of the plate thickness W. The nonlinear portion R2 is a portion where the plate thickness W changes suddenly except for the arc portion F, from the first end E to the second end S of the orbiting-side spiral wall 32b. Of the boundaries between the two linear portions R1 and the nonlinear portion R2, the boundary between the linear portion R1 with the smaller inflection angle and the nonlinear portion R2 is set as the "second inflection angle G2". In addition, the boundary between the linear portion R1 with the larger inflection angle and the nonlinear portion R2 is set as the "third inflection angle G3". Therefore, the nonlinear portion R2 is a portion located between the second inflection angle G2 and the third inflection angle G3. The nonlinear portion R2 is a thin-walled portion where the plate thickness W is thinner than the surroundings, with the boundary between the second inflection angle G2 and the third inflection angle G3. Therefore, the orbiting-side spiral wall 32b has a thin-walled portion whose plate thickness W is thinner than the surrounding area.

[0037] In the nonlinear portion R2, the plate thickness W rapidly becomes thinner and reaches a minimum value as the inflection angle increases from the second inflection angle G2, and then rapidly becomes thicker from the minimum value toward the third inflection angle G3. Therefore, the plate thickness W of the orbiting-side spiral wall 32b is minimal in the nonlinear portion R2.

[0038] As shown in Fig. 2, in the nonlinear portion R2, the outer peripheral wall 321 and the inner peripheral wall 322 of the orbiting-side spiral wall 32b are displaced so as to approach each other in the thickness direction. In other words, the thickness W is not reduced by displacing only one of the outer peripheral wall 321 and the inner peripheral wall 322. The thickness W of the orbiting-side spiral wall 32b is the thinnest at a position where the outer peripheral wall 321 and the inner peripheral wall 322 approach each other in the thickness direction of the orbiting-side spiral wall 32b. The thickness W of the orbiting-side spiral wall 32b has a minimum value at the position where it is thinnest.

[0039] As shown in Fig. 5, in the orbiting-side spiral wall 32b, the inflection angle obtained by subtracting 360° from the second end S is set as the reference inflection angle G. This reference inflection angle G is located within the range of the nonlinear portion R2. In other words, the reference inflection angle G is located between the second inflection angle G2 and the third inflection angle G3. Therefore, the nonlinear portion R2 includes an inflection angle obtained by subtracting 360° from the maximum inflection angle. Therefore, the reference inflection angle G is provided at a position where the plate thickness W of the orbiting-side spiral wall 32b is thinner than the linear portion R1.

[0040] Also, the minimum value of the thickness W of the orbiting-side spiral wall 32b is located at an expansion angle closer to the first end E than the reference expansion angle G. That is, the minimum value of the thickness W is located at an expansion angle smaller than the reference expansion angle G. For this reason, the thickness W is minimum at the nonlinear portion R2 of the orbiting-side spiral wall 32b at an expansion angle that is 360° or more less than the maximum expansion angle. Therefore, the thinnest part of the thickness W of the orbiting-side spiral wall 32b is located at an expansion angle smaller than the expansion angle that is 360° or more less than the maximum expansion angle at the nonlinear portion R2. It can be said that the second end S of the orbiting-side spiral wall 32b overlaps the nonlinear portion R2 in the radial direction of the orbiting-side substrate 32a.

[0041] <Action and Effects> Next, the operation and effects of the scroll compressor 10 will be described. (1) Figures 3 and 4 show an orbiting scroll 60 of a comparative example. The orbiting scroll 60 of the comparative example can be said to be an orbiting scroll provided in a general scroll-type compressor.

[0042] The orbiting scroll 60 of the comparative example has an orbiting-side substrate 61 and an orbiting-side spiral wall 62 that does not include a nonlinear portion R2. As shown by the two-dot chain line in FIG. 5, the thickness W of the orbiting-side spiral wall 62 of the comparative example decreases linearly with an increase in the extension angle from the first extension angle G1 to the second end S. That is, the thickness W of the orbiting-side spiral wall 62 of the comparative example decreases at a constant thickness change rate from the first extension angle G1. Therefore, it can be said that the orbiting-side spiral wall 62 of the comparative example is a linear portion R1 except for the arc portion F. Note that, as shown in FIG. 3, the extension angle at the second end S2 of the comparative example is smaller than the extension angle at the second end S1 of the present embodiment. Therefore, the number of turns of the orbiting-side spiral wall 32b of the present embodiment is greater than the number of turns of the orbiting-side spiral wall 62 of the comparative example.

[0043] As shown in FIG. 4, consider a case where the diameter of the orbiting-side substrate 61 is the same as the diameter of the orbiting-side substrate 32a in the orbiting scroll 60 of the comparative example. In the comparative example, if the number of turns of the orbiting-side spiral wall 62 is increased, the position of the second end S where the maximum value of the extension angle is located will protrude from the outer edge of the orbiting-side substrate 61. However, in this embodiment, the plate thickness W of the part of the orbiting-side spiral wall 32b that is a point where the position of the second end S that would protrude is subtracted by 360° in extension angle from the position of the second end S that would protrude is reduced from the surroundings. This allows the position of the second end S of the orbiting-side spiral wall 32b to be located inside the outer edge of the orbiting-side substrate 32a, as shown in FIG. 2. As a result, the position of the second end S does not protrude from the outer edge of the orbiting-side substrate 32a, and the number of turns of the orbiting-side spiral wall 32b can be increased compared to the comparative example. That is, as shown by the two-dot chain line in Fig. 3, the position of the second end S where the extension angle is maximum can be extended from the second end S2 in the comparative example to the second end S1 in the present embodiment along the circumferential direction of the orbiting-side base plate 32a. In other words, the number of turns of the orbiting-side spiral wall 32b can be increased without increasing the diameter of the orbiting-side base plate 32a.

[0044] As a result, when the first compression chamber is formed in the orbiting scroll 32 of this embodiment, the amount of fluid trapped in the first compression chamber is increased by the nonlinear portion R2 compared to the comparative example. That is, the plate thickness W of the outer peripheral wall 321 of the orbiting-side spiral wall 32b is reduced so as to be recessed, thereby increasing the amount of fluid trapped in the first compression chamber.

[0045] Similarly, when the second compression chamber is formed, the amount of fluid trapped in the second compression chamber is increased by the nonlinear portion R2 compared to the comparative example. That is, the amount of fluid trapped in the second compression chamber is increased by reducing the plate thickness W of the inner circumferential wall 322 of the orbiting-side spiral wall 32b so as to be recessed.

[0046] Therefore, according to the orbiting scroll 32 having the nonlinear portion R2, the number of turns of the orbiting-side spiral wall 32b can be increased without increasing the diameter of the orbiting-side base plate 32a. As a result of being able to increase the number of turns of the orbiting-side spiral wall 32b, the amount of fluid that can be trapped in the compression chamber 33 increases, and the compression efficiency of the scroll compressor 10 can be improved.

[0047] Therefore, while taking into consideration the ease of installation in the installation site and there are restrictions on the size of the scroll compressor 10, it is possible to improve the compression efficiency without increasing the size of the orbiting scroll 32 and, ultimately, the housing 11.

[0048] (2) The thin portion is the nonlinear portion R2. The plate thickness W of the orbiting-side spiral wall 32b is extremely small at the nonlinear portion R2. The scroll compressor 10 has a linear portion R1 around the nonlinear portion R2, which is a thin portion. By having the nonlinear portion R2 including the thin portion, the number of turns of the orbiting-side spiral wall 32b can be increased without degrading the performance compared to a typical scroll compressor.

[0049] (3) The plate thickness W of the orbiting-side spiral wall 32b is minimal at an expansion angle that is 360° or more less than the maximum expansion angle. Therefore, the nonlinear portion R2 can be formed at an expansion angle that is smaller than the position that is 360° or more less than the second end S of the orbiting-side spiral wall 32b.

[0050] (4) The nonlinear portion R2 is provided at a position that includes an expansion angle that is the maximum expansion angle minus 360°. Therefore, the plate thickness W at the portion that forms the outer periphery of the orbiting-side spiral wall 32b does not become thinner than the plate thickness W formed by the involute curve. Therefore, even with the orbiting-side spiral wall 32b that includes the nonlinear portion R2, it is possible to suppress a decrease in rigidity on the outer periphery side and suppress vibration of the orbiting-side spiral wall 32b.

[0051] (5) By providing the nonlinear portion R2 in the orbiting-side spiral wall 32b, the number of turns of the orbiting-side spiral wall 32b can be made longer than in the comparative example. Accordingly, the number of turns of the fixed-side spiral wall 31b can also be made longer than in the comparative example. As a result, the compression stroke by the fixed-side spiral wall 31b and the orbiting-side spiral wall 32b, that is, the time from the start of compression to discharge, can be made longer, so that overcompression can be suppressed. In addition, since the number of turns of the orbiting-side spiral wall 32b and the fixed-side spiral wall 31b can be made longer, the pressure difference between the multiple compression chambers 33 at the same time decreases, so that recompression can be suppressed.

[0052] The embodiment can be modified as follows: The embodiment and the following modified examples can be combined with each other to the extent that there is no technical contradiction. The non-linear portion R2 may be formed by recessing either the outer circumferential wall 321 or the inner circumferential wall 322 toward the other.

[0053] The portion where the plate thickness W is minimal may be located at a reference inflection angle G, which is an inflection angle obtained by subtracting 360° from the maximum inflection angle, or may be located at an inflection angle larger than the reference inflection angle G.

[0054] The orbiting-side spiral wall 32b may have a shape having a plurality of portions where the thickness W is minimal. In this case, the reference deployment angle G is included in one of the nonlinear portions R2 including the portions where the thickness W is minimal.

[0055] The number of turns may be changed by changing the maximum value of the expansion angle of the orbiting-side spiral wall 32b. For example, the maximum value of the expansion angle of the orbiting-side spiral wall 32b may be slightly greater than 360° and the number of turns may be slightly greater than one, or the maximum value of the expansion angle may be 540° and one and a half turns. Furthermore, the maximum value of the expansion angle of the orbiting-side spiral wall 32b may be 1080° and the number of turns may be three. The number of locations where the nonlinear section R2 is provided may be adjusted according to the number of turns.

[0056] The scroll compressor 10 does not have to be an electric scroll compressor. For example, the scroll compressor 10 may be one that is driven by an engine. [Explanation of symbols]

[0057] W...plate thickness, R1...linear portion, R2...nonlinear portion as thin portion, 10...scroll type compressor, 31...fixed scroll, 31a...fixed side base plate, 31b...fixed side spiral wall, 32...orbiting scroll, 32a...orbiting side base plate, 32b...orbiting side spiral wall, 33...compression chamber.

Claims

1. a fixed scroll having a fixed side base plate and a fixed side spiral wall standing upright from the fixed side base plate; a disk-shaped orbiting-side base plate facing the fixed-side base plate, and an orbiting scroll standing from the orbiting-side base plate toward the fixed-side base plate and having an orbiting-side spiral wall meshing with the fixed-side spiral wall, wherein the orbiting scroll orbits to compress a fluid in a compression chamber defined by the fixed scroll and the orbiting scroll, The orbiting-side volute wall has an involute curve and a plate thickness. the orbiting-side spiral wall has a linear portion where the plate thickness decreases linearly as the expansion angle increases, and a nonlinear portion where the plate thickness changes nonlinearly as the expansion angle increases, the orbiting-side spiral wall has a thin-walled portion having a plate thickness thinner than that of a surrounding area, The thin portion includes a portion at an inflection angle that is 360° less than the maximum inflection angle, the thin portion is the nonlinear portion, The scroll compressor according to claim 1, wherein the plate thickness is minimized in the nonlinear portion.

2. 2. The scroll compressor according to claim 1, wherein the wall thickness of the orbiting-side scroll wall is minimal at a portion of the nonlinear portion at an extension angle that is 360° or more less than the maximum extension angle.

Images