Screw compressors and refrigeration units

Abstract

The gate (52) has a first sealing line (55) and a second sealing line (56). The first sealing line (55) and the second sealing line (56) are asymmetrical with respect to a first imaginary straight line (L1), which passes through the rotation center (O) of the gate rotor (51) and the first intermediate position (A) on the front end side of the gate (52) between the first sealing line (55) and the second sealing line (56). The spiral groove (40) has a shape corresponding to the gate (52).

Description

Technical Field

[0001] This disclosure relates to a screw compressor and a refrigeration device. Background Technology

[0002] Patent Document 1 describes a technique for manufacturing screw rotors for screw compressors using a five-axis machining center. In this five-axis machining center, the workpiece is machined by moving a cutting tool, such as an end mill, mounted on the spindle, and the workpiece, mounted on a retainer, respectively.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent No. 4229213 Summary of the Invention

[0006] -The technical problem the invention aims to solve-

[0007] However, the relative angle between the cutting tool and the central axis of the screw rotor will increase depending on the shape of the helical groove, especially when cutting the axial end of the helical groove, the spindle and the rotary table of the five-axis machining center may interfere.

[0008] The purpose of this disclosure is to avoid interference between the spindle and the rotary table when machining the helical groove corresponding to the gate using a five-axis machining center by focusing on the shape of the gate.

[0009] - Technical solutions used to solve technical problems -

[0010] The first aspect of this disclosure relates to a screw compressor comprising a screw rotor 30 and a guillotine rotor 51. The screw rotor 30 has a plurality of helical grooves 40, and the guillotine rotor 51 has a guillotine 52 that engages with the helical grooves 40 of the screw rotor 30. The guillotine 52 has a first sealing line 55 and a second sealing line 56 that contact the sidewall surface 41 of the helical grooves 40 of the screw rotor 30. The first sealing line 55 and the second sealing line 56 are asymmetrical with respect to a first imaginary straight line L1. The first imaginary straight line L1 passes through the rotation center O of the guillotine rotor 51 and a first intermediate position A located between the first sealing line 55 and the second sealing line 56 on the front end side of the guillotine 52. The helical grooves 40 are shaped corresponding to the guillotine 52.

[0011] In the first aspect, by focusing on the shape of the gate 52, interference between the spindle and the rotary table can be avoided when machining the spiral groove 40 corresponding to the gate 52 using a five-axis machining center.

[0012] The second aspect of this disclosure, based on the screw compressor of the first aspect, involves a second imaginary straight line L2 inclined at a predetermined angle relative to the first imaginary straight line L1, the second imaginary straight line L2 passing through the rotation center O of the gate rotor 51 and the base end side of the gate 52 at a second intermediate position B located between the first sealing line 55 and the second sealing line 56.

[0013] In the second aspect, by focusing on the shape of the gate 52, interference between the spindle and the rotary table can be avoided when machining the spiral groove 40 corresponding to the gate 52 using a five-axis machining center.

[0014] The third aspect of this disclosure, based on the screw compressor of the first or second aspect, wherein when viewed from the axial direction of the gate rotor 51, the maximum angle formed by the central axis 33 of the screw rotor 30 and the surface in the side wall 41 of the spiral groove 40 that contacts the first sealing line 55 is less than 145°.

[0015] In the third aspect, by setting the maximum angle to below 145°, interference between the spindle and the rotary table can be avoided when machining the spiral groove 40 corresponding to the gate 52 using a five-axis machining center.

[0016] The fourth aspect of this disclosure is based on the screw compressor of the third aspect, wherein the maximum angle is 135° or less.

[0017] In the fourth aspect, by setting the maximum angle to below 135°, interference between the spindle and the rotary table can be avoided when machining the spiral groove 40 corresponding to the gate 52 using a five-axis machining center.

[0018] The fifth aspect of this disclosure is based on the screw compressor of the fourth aspect, wherein the maximum angle is less than 120°.

[0019] In the fifth aspect, by setting the maximum angle to below 120°, interference between the spindle and the rotary table can be avoided when machining the spiral groove 40 corresponding to the gate 52 using a five-axis machining center.

[0020] Based on the screw compressor of any one of the first to fifth aspects of this disclosure, the corner between the bottom wall surface 42 and the side wall surface 41 of the spiral groove 40 is formed in a curved shape.

[0021] In the sixth aspect, the spiral groove 40 can be formed by bending the corner between the bottom wall surface 42 and the side wall surface 41 of the spiral groove 40 using a tapered end mill.

[0022] The seventh aspect of this disclosure is based on the screw compressor of any one of the first to sixth aspects, wherein a first sealing end 31 and a second sealing end 32 are provided at both axial ends of the screw rotor 30, and the spiral groove 40 is formed between the first sealing end 31 and the second sealing end 32.

[0023] In the seventh aspect, even a screw rotor 30 with sealing surfaces at both axial ends can form a helical groove 40 between the first sealing end 31 and the second sealing end 32.

[0024] The eighth aspect of this disclosure relates to a refrigeration apparatus comprising a screw compressor 10 according to any one of the first to seventh aspects, and a refrigerant circuit 1a for supplying refrigerant compressed by the screw compressor 10.

[0025] In the eighth aspect, a refrigeration apparatus including a screw compressor 10 can be provided. Attached Figure Description

[0026] Figure 1 This is a refrigerant circuit diagram showing the structure of the refrigeration apparatus according to the first embodiment;

[0027] Figure 2 This is a longitudinal sectional view showing the structure of a screw compressor;

[0028] Figure 3 This is a transverse sectional view showing the structure of the screw compressor as seen from the high-pressure chamber side;

[0029] Figure 4 This is a top view showing the arrangement between the screw rotor and the brake rotor;

[0030] Figure 5 This is a top view showing the structure of a five-axis machining center;

[0031] Figure 6 It is a top view illustrating the relative angle of the cutting tool with respect to the central axis of the screw rotor;

[0032] Figure 7 This is a top view showing the structure of the brake rotor as a comparative example;

[0033] Figure 8 This is a top view illustrating the relative angle of the cutting tool with respect to the central axis of the screw rotor, used as a comparative example.

[0034] Figure 9 This is a top view showing the structure of the guillotine rotor;

[0035] Figure 10 It is a top view illustrating the relative angle of the cutting tool with respect to the central axis of the screw rotor;

[0036] Figure 11 This is a diagram illustrating the shape of the corner between the sidewall and bottomwall of the spiral groove;

[0037] Figure 12 This is a top view showing the structure of the guillotine rotor according to the second embodiment;

[0038] Figure 13 It is a top view illustrating the relative angle of the cutting tool with respect to the central axis of the screw rotor;

[0039] Figure 14 This is a top view showing the structure of the guillotine rotor according to the third embodiment;

[0040] Figure 15 It is a top view illustrating the relative angle of the cutting tool with respect to the central axis of the screw rotor;

[0041] Figure 16 This is a top view showing the structure of the guillotine rotor according to the fourth embodiment;

[0042] Figure 17 It is a top view illustrating the relative angle of the cutting tool with respect to the central axis of the screw rotor. Detailed Implementation

[0043] (First Implementation)

[0044] like Figure 1 As shown, a screw compressor 10 is installed in a refrigeration unit 1. The refrigeration unit 1 has a refrigerant circuit 1a filled with refrigerant. The refrigerant circuit 1a includes the screw compressor 10, a radiator 3, a pressure reducing mechanism 4, and an evaporator 5. The pressure reducing mechanism 4 is, for example, an expansion valve. The refrigerant circuit 1a performs a vapor compression refrigeration cycle.

[0045] Refrigeration unit 1 is an air conditioning unit. The air conditioning unit can be a dedicated refrigeration unit, a dedicated heating unit, or an air conditioning unit that switches between refrigeration and heating. In this case, the air conditioning unit has a switching mechanism (e.g., a four-way reversing valve) for switching the refrigerant circulation direction. Refrigeration unit 1 can also be a water heater, a cooling unit, a cooling device for cooling the air inside the storage area, etc. The cooling device cools the air inside the cold storage, freezer, container, etc.

[0046] <Overall Structure of a Screw Compressor>

[0047] like Figure 2 and Figure 3 As shown, the screw compressor 10 includes a screw rotor 30 and two guillotine rotor assemblies 50. The screw compressor 10 includes a housing 11, an electric motor 17, and a drive shaft 18.

[0048] like Figure 2 As shown, the housing 11 is formed into a cylindrical shape closed at both ends. The housing 11 is arranged in a shape with its length direction approximately horizontal. The housing 11 has a cylindrical portion 16. The cylindrical portion 16 is a portion formed into a cylindrical shape. The cylindrical portion 16 is arranged near the center in the length direction of the housing 11. A screw rotor 30 is housed in the cylindrical portion 16.

[0049] An intake port 12 and an exhaust port 13 are formed on the housing 11. The intake port 12 is formed at one end of the housing 11. Figure 2 The upper part of the left end of the housing 11. The nozzle 13 is formed at the other end of the housing 11. Figure 2 The upper part of the right end of the middle.

[0050] A low-pressure chamber 14 and a high-pressure chamber 15 are formed inside the housing 11. The low-pressure chamber 14 is formed at one end of the housing 11 closer to the cylindrical portion 16, and the low-pressure chamber 14 communicates with the suction port 12. The high-pressure chamber 15 is formed at the other end of the housing 11 closer to the cylindrical portion 16, and the high-pressure chamber 15 communicates with the nozzle 13.

[0051] The electric motor 17 is located in the low-pressure chamber 14. The drive shaft 18 connects the electric motor 17 and the screw rotor 30. The electric motor 17 drives the screw rotor 30 to rotate.

[0052] like Figure 3 As shown, the brake rotor assembly 50 includes a brake rotor 51 and a support member 54. The brake rotor 51 is a flat plate made of resin. The support member 54 is a metal component. The support member 54 is configured to contact the back surface of the brake rotor 51 and support the brake rotor 51.

[0053] exist Figure 3 In the middle, the front surface of the gate rotor 51 of the gate rotor assembly 50, which is arranged on the right side of the screw rotor 30, faces upward. Additionally, in Figure 3 In the middle, the front surface of the gate rotor 51 of the gate rotor assembly 50 arranged on the left side of the screw rotor 30 faces downward.

[0054] <Screw rotor>

[0055] like Figure 4 As shown, the screw rotor 30 is a cylindrical metal component. A first sealing end 31 and a second sealing end 32 are provided at both axial ends of the screw rotor 30. Regarding the screw rotor 30, Figure 4 The lower end is the first sealing end 31. Figure 4 The upper end of the screw rotor 30 is the second sealing end 32. In the cylindrical portion 16 of the housing 11, the first sealing end 31 of the screw rotor 30 is located on the high-pressure chamber 15 side, and the second sealing end 32 of the screw rotor 30 is located on the low-pressure chamber 14 side.

[0056] A plurality of helical grooves 40 are formed on the screw rotor 30. The helical grooves 40 are formed on the outer periphery of the screw rotor 30. The helical grooves 40 are grooves that extend helically along the central axis 33 of the screw rotor 30. The helical grooves 40 are formed between the first sealing end 31 and the second sealing end 32. The helical grooves 40 open only on the outer peripheral surface of the screw rotor 30. Therefore, in the screw rotor 30 of this embodiment, the helical grooves 40 do not open on the end face of the screw rotor 30. The helical grooves 40 have a side wall surface 41 and a bottom wall surface 42.

[0057] <Gate rotor>

[0058] like Figure 4 As shown, multiple gates 52 are arranged circumferentially on the gate rotor 51. Each gate 52 is a flat, approximately rectangular plate. The gates 52 enter the helical grooves 40 of the screw rotor 30 and slide along the walls of the helical grooves 40 to form a first compression chamber 21 and a second compression chamber 22. It should be noted that the specific shape of the gate rotor 51 will be described later.

[0059] A first sealing line 55 and a second sealing line 56 are formed on the side of the gate 52. The first sealing line 55 and the second sealing line 56 are straight lines extending from the base end of the gate 52 toward the front end. The first sealing line 55 and the second sealing line 56 of the gate 52, which enter the spiral groove 40, slide along the side wall surface 41 of the spiral groove 40.

[0060] When the screw rotor 30 rotates, the gate rotor 51 rotates along with the screw rotor 30. Figure 4 In the middle, the right-hand gate rotor 51 rotates counterclockwise. The left-hand gate rotor 51 rotates clockwise.

[0061] <Compression Chamber>

[0062] like Figure 2 and Figure 3 As shown, in the screw compressor 10, a first compression chamber 21 and a second compression chamber 22 are formed by a screw rotor 30, a brake rotor 51, and a cylindrical portion 16 of the housing 11. The first compression chamber 21 and the second compression chamber 22 are sealed spaces enclosed by the wall surface of the helical groove 40 of the screw rotor 30, the front surface of the brake 52 of the brake rotor 51, and the inner circumferential surface of the cylindrical portion 16.

[0063] In the screw compressor 10 of this embodiment, Figure 3 The compression chamber on the lower side of the screw rotor 30 is the first compression chamber 21. Figure 3 The compression chamber on the upper side of the screw rotor 30 is the second compression chamber 22.

[0064] Operating Procedures of a Screw Compressor

[0065] In the screw compressor 10, the screw rotor 30 is driven by the electric motor 17. When the screw rotor 30 rotates, the guillotine rotor 51, which meshes with the screw rotor 30, rotates. When the guillotine rotor 51 rotates, the guillotine rotor 52 enters the helical groove 40 of the screw rotor 30 and moves relative to the suction side end of the helical groove 40 towards the discharge side end. As a result, the volumes of the first compression chamber 21 and the second compression chamber 22 gradually decrease, thereby compressing the refrigerant in the first compression chamber 21 and the second compression chamber 22.

[0066] The screw compressor 10 of this embodiment performs two-stage compression. Specifically, refrigerant flowing into the low-pressure chamber 14 through the suction port 12 flows into the first compression chamber 21 and is compressed. The refrigerant compressed in the first compression chamber 21 is ejected from the first compression chamber 21 and flows into the second compression chamber 22 through a passage formed in the housing 11. The refrigerant flowing into the second compression chamber 22 is compressed and then ejected towards the high-pressure chamber 15. The refrigerant flowing into the high-pressure chamber 15 is ejected towards the outside of the screw compressor 10 through the nozzle 13.

[0067] - Manufacturing method of screw rotor -

[0068] The manufacturing method of the screw rotor 30 of this embodiment will be described.

[0069] like Figure 5 As shown, the screw rotor 30 is machined using a five-axis machining center 100.

[0070] The five-axis machining center 100 includes a spindle 101 on which cutting tools 110 such as end mills are mounted, and a column 102 on which the spindle 101 is mounted. Additionally, the five-axis machining center 100 includes a rotary table 104 and a holding part 105. The rotary table 104 is mounted on a base table 103 and can rotate freely, while the holding part 105 is provided on the rotary table 104 and holds the screw rotor 30, which is the workpiece to be cut.

[0071] In the five-axis machining center 100, three degrees of freedom are assigned to the cutting tool 110 side and two degrees of freedom are assigned to the screw rotor 30 side. Specifically, the spindle 101 can move freely in the X-axis direction orthogonal to its rotation axis, the Y-axis direction orthogonal to its rotation axis and the X-axis direction, and the Z-axis direction which is the rotation axis direction.

[0072] The holding part 105 can rotate freely about its central axis (about axis A). In addition, the rotary table 104 on which the holding part 105 is mounted can rotate freely about an axis orthogonal to the axis of the holding part 105 (about axis B).

[0073] That is, in this five-axis machining center 100, the cutting tool 110 can move freely in parallel in the X-axis, Y-axis and Z-axis directions, while the screw rotor 30 can rotate freely around the A-axis and B-axis.

[0074] In the five-axis machining center 100, the screw rotor 30 is machined by moving the cutting tool 110 based on a tool path provided in advance as numerical data. The five-axis machining center 100 uses multiple cutting tools 110 to perform multiple operations from roughing to finishing in sequence.

[0075] like Figure 6 As shown, the relative angle θ between the cutting tool 110 and the central axis 33 of the screw rotor 30 reaches its maximum angle (e.g., 150°) when machining the axial end of the helical groove 40. Therefore, the angle range of the tool posture of the cutting tool 110 required for machining the helical groove 40 of a typical screw rotor 30 is: the relative angle θ between the cutting tool 110 and the central axis 33 of the screw rotor 30 is 25° to 150°.

[0076] However, in a typical five-axis machining center 100, the range of motion of the five-axis machining center 100 is from the relative angle θ of the cutting tool 110 to the central axis 33 of the screw rotor 30 up to 135°. The holding part 105 on the rotary table 104 will interfere with the main body of the spindle 101.

[0077] Furthermore, even when using a special five-axis machining center 100 with a range of motion where the relative angle θ between the cutting tool 110 and the central axis 33 of the screw rotor 30 can reach 145°, interference between the spindle 101 and the rotary table 104 cannot be avoided. Therefore, during the finishing process, it is necessary to perform an additional operation to change the holding posture of the screw rotor 30 relative to the holding part 105, thereby consuming machining time.

[0078] Therefore, the inventors of this application conducted the following research: by working on the shape of the gate 52, they were able to avoid interference between the spindle 101 and the rotary table 104 when machining the spiral groove 40 corresponding to the gate 52 using a five-axis machining center 100.

[0079] First, as a comparative example, the shape of a typical gate 52 will be described. For example... Figure 7 As shown, the gate rotor 51 has a gate 52 that engages with the helical groove 40 of the screw rotor 30. The gate 52 has a first sealing line 55 and a second sealing line 56 that contact the side wall surface 41 of the helical groove 40 of the screw rotor 30.

[0080] The first sealing line 55 and the second sealing line 56 are symmetrical with respect to the first imaginary straight line L1, wherein the first imaginary straight line L1 passes through the rotation center O of the gate rotor 51 and the first intermediate position A located between the first sealing line 55 and the second sealing line 56 on the front end side of the gate 52.

[0081] Furthermore, the second imaginary line L2 coincides with the first imaginary line L1, wherein the second imaginary line L2 passes through the rotation center O of the gate rotor 51 and the second intermediate position B located between the first sealing line 55 and the second sealing line 56 on the base end side of the gate 52. Therefore, the angle between the first imaginary line L1 and the second imaginary line L2 is 0°.

[0082] like Figure 8 As shown, a groove machining process is performed to carve a spiral groove 40 corresponding to the shape of the gate 52 into the cylindrical workpiece. After the groove machining process, the side wall surface 41 and bottom wall surface 42 of the spiral groove 40 are finished to make the shape of the spiral groove 40 meet the design value of the screw rotor 30. During the finishing process, the side edge of the screw rotor 30 is cut using the side of the cutting tool 110.

[0083] Here, as Figure 8 As shown, the central axis of the cutting tool 110 is parallel to the central axis 33 of the screw rotor 30, and the front end of the cutting tool 110 is at... Figure 8 The state of the cutting tool 110 facing downward is set to the case where the relative angle θ between the cutting tool 110 and the central axis 33 of the screw rotor 30 is 0°.

[0084] The maximum angle of the cutting tool 110 when machining the axial end of the screw rotor 30 is related to the shape of the gate 52. Figure 8 In the example shown, the maximum angle of the cutting tool 110 is 150°. Therefore, even if a special five-axis machining center 100 with a range of motion where the relative angle θ between the cutting tool 110 and the central axis 33 of the screw rotor 30 can reach 145° is used, it is impossible to avoid interference between the spindle 101 and the rotary table 104.

[0085] Next, the shape of the gate 52 according to this embodiment will be described. For example... Figure 9 As shown, the gate rotor 51 has a gate 52 that engages with the helical groove 40 of the screw rotor 30. The gate 52 has a first sealing line 55 and a second sealing line 56 that contact the side wall surface 41 of the helical groove 40 of the screw rotor 30.

[0086] The first sealing line 55 and the second sealing line 56 are asymmetrical relative to the first imaginary straight line L1, wherein the first imaginary straight line L1 passes through the rotation center O of the gate rotor 51 and the first intermediate position A located between the first sealing line 55 and the second sealing line 56 on the front end side of the gate 52.

[0087] Furthermore, the second imaginary line L2 is inclined at a predetermined angle relative to the first imaginary line L1, wherein the second imaginary line L2 passes through the rotation center O of the gate rotor 51 and the second intermediate position B located between the first sealing line 55 and the second sealing line 56 on the base end side of the gate 52. Let α be the angle between the first imaginary line L1 and the second imaginary line L2.

[0088] like Figure 10 As shown, a groove machining process is performed to carve a spiral groove 40 corresponding to the shape of the gate 52 into the cylindrical workpiece. After the groove machining process, the side wall surface 41 and bottom wall surface 42 of the spiral groove 40 are finished to make the shape of the spiral groove 40 meet the design value of the screw rotor 30. During the finishing process, the side edge of the screw rotor 30 is cut using the side of the cutting tool 110.

[0089] Here, as Figure 10 As shown, the central axis of the cutting tool 110 is parallel to the central axis 33 of the screw rotor 30, and the front end of the cutting tool 110 is at... Figure 10 The state of the cutting tool 110 facing downward is set to the case where the relative angle θ between the cutting tool 110 and the central axis 33 of the screw rotor 30 is 0°.

[0090] Here, when viewed axially from the gate rotor 51, the maximum angle formed by the central axis 33 of the screw rotor 30 and the surface in the side wall 41 of the helical groove 40 that contacts the first sealing line 55, i.e., the maximum angle of the cutting tool 110 when machining the axial end of the screw rotor 30, is related to the shape of the gate 52. Figure 10 In the example shown, the angle α between the first imaginary straight line L1 and the second imaginary straight line L2 on the gate 52 is designed such that the maximum angle of the cutting tool 110 is 125°.

[0091] Thus, if it forms Figure 9 and Figure 10 The shape of the gate 52 shown is precision machined within a relative angle θ of 25° to 125° with the cutting tool 110. As a result, when machining the spiral groove 40 using the five-axis machining center 100, interference between the spindle 101 and the rotary table 104 can be avoided.

[0092] Here, as Figure 11As shown, the corner between the side wall surface 41 and the bottom wall surface 42 of the spiral groove 40, which contacts the first sealing line 55 of the gate 52, is an acute angle and cannot be machined at an acute angle. Therefore, for the corner between the side wall surface 41 and the bottom wall surface 42 of the spiral groove 40, a tapered end mill is used to form the corner into a curved shape. The curvature of the curved shape connecting the side wall surface 41 and the bottom wall surface 42 only needs to be equal to, for example, the outer diameter of the gate rotor 51. It should be noted that, for the gate 52, the corner of the front end side of the gate 52 also needs to be chamfered in accordance with the curved shape of the corner of the spiral groove 40.

[0093] -Effects of the implementation method-

[0094] According to the features of this embodiment, the first sealing line 55 and the second sealing line 56 are asymmetrical in shape relative to the first imaginary straight line L1. The first imaginary straight line L1 passes through the rotation center O of the gate rotor 51 and the first intermediate position A located between the first sealing line 55 and the second sealing line 56 on the front end side of the gate 52. The spiral groove 40 has a shape corresponding to the gate 52. Thus, by focusing on the shape of the gate 52, interference between the spindle 101 and the rotary table 104 can be avoided when machining the spiral groove 40 corresponding to the gate 52 using the five-axis machining center 100.

[0095] According to the features of this embodiment, the second imaginary straight line L2 is inclined at a predetermined angle relative to the first imaginary straight line L1, wherein the second imaginary straight line L2 passes through the rotation center O of the gate rotor 51 and the second intermediate position B located between the first sealing line 55 and the second sealing line 56 on the base end side of the gate 52. In this way, by focusing on the shape of the gate 52, interference between the spindle 101 and the rotary table 104 can be avoided when machining the helical groove 40 corresponding to the gate 52 using the five-axis machining center 100.

[0096] According to the features of this embodiment, the spiral groove 40 can be formed by forming the corner between the bottom wall surface 42 and the side wall surface 41 of the spiral groove 40 into a curved shape, thereby using a tapered end mill.

[0097] According to the features of this embodiment, even a screw rotor 30 with sealing surfaces at both axial ends can form a helical groove 40 between the first sealing end 31 and the second sealing end 32.

[0098] According to the features of this embodiment, it includes a screw compressor 10 and a refrigerant circuit 1a for supplying refrigerant that has been compressed by the screw compressor 10. Therefore, a refrigeration apparatus 1 including a screw compressor 10 can be provided.

[0099] (Second Implementation)

[0100] Hereinafter, the same symbols will be used to mark the parts that are the same as those in the first embodiment described above, and only the differences will be explained.

[0101] like Figure 12 As shown, the gate rotor 51 has a gate 52 that engages with the helical groove 40 of the screw rotor 30. The gate 52 has a first sealing line 55 and a second sealing line 56 that contact the side wall surface 41 of the helical groove 40 of the screw rotor 30.

[0102] The first sealing line 55 and the second sealing line 56 are asymmetrical relative to the first imaginary straight line L1, wherein the first imaginary straight line L1 passes through the rotation center O of the gate rotor 51 and the first intermediate position A located between the first sealing line 55 and the second sealing line 56 on the front end side of the gate 52.

[0103] Furthermore, the second imaginary line L2 is inclined at a predetermined angle relative to the first imaginary line L1, wherein the second imaginary line L2 passes through the rotation center O of the gate rotor 51 and the second intermediate position B located between the first sealing line 55 and the second sealing line 56 on the base end side of the gate 52. Let α be the angle between the first imaginary line L1 and the second imaginary line L2.

[0104] like Figure 13 As shown, the central axis of the cutting tool 110 is parallel to the central axis 33 of the screw rotor 30, and the front end of the cutting tool 110 is at... Figure 13 The state of the cutting tool 110 facing downward is set to the case where the relative angle θ between the cutting tool 110 and the central axis 33 of the screw rotor 30 is 0°.

[0105] The maximum angle of the cutting tool 110 when machining the axial end of the screw rotor 30 is related to the shape of the gate 52. Figure 13 In the example shown, the angle α between the first imaginary straight line L1 and the second imaginary straight line L2 on the gate 52 is designed such that the maximum angle of the cutting tool 110 is 145°. Figure 12 The angle α of the gate 52 shown is smaller than the angle α of the gate 52 in the first embodiment described above, where the maximum angle of the cutting tool 110 is 125°.

[0106] Thus, if it forms Figure 12 and Figure 13 The shape of the gate 52 shown is finished within the range of 25° to 145° relative angle θ of the cutting tool 110. In this way, by setting the maximum angle of the cutting tool 110 to below 145°, interference between the spindle 101 and the rotary table 104 can be avoided when machining the helical groove 40 corresponding to the gate 52 using the five-axis machining center 100.

[0107] (Third Implementation)

[0108] like Figure 14 As shown, the gate rotor 51 has a gate 52 that engages with the helical groove 40 of the screw rotor 30. The gate 52 has a first sealing line 55 and a second sealing line 56 that contact the side wall surface 41 of the helical groove 40 of the screw rotor 30.

[0109] The first sealing line 55 and the second sealing line 56 are asymmetrical relative to the first imaginary straight line L1, wherein the first imaginary straight line L1 passes through the rotation center O of the gate rotor 51 and the first intermediate position A located between the first sealing line 55 and the second sealing line 56 on the front end side of the gate 52.

[0110] Furthermore, the second imaginary line L2 is inclined at a predetermined angle relative to the first imaginary line L1, wherein the second imaginary line L2 passes through the rotation center O of the gate rotor 51 and the second intermediate position B located between the first sealing line 55 and the second sealing line 56 on the base end side of the gate 52. Let α be the angle between the first imaginary line L1 and the second imaginary line L2.

[0111] like Figure 15 As shown, the central axis of the cutting tool 110 is parallel to the central axis 33 of the screw rotor 30, and the front end of the cutting tool 110 is at... Figure 15 The state of the cutting tool 110 facing downward is set to the case where the relative angle θ between the cutting tool 110 and the central axis 33 of the screw rotor 30 is 0°.

[0112] The maximum angle of the cutting tool 110 when machining the axial end of the screw rotor 30 is related to the shape of the gate 52. Figure 15 In the example shown, the angle α between the first imaginary straight line L1 and the second imaginary straight line L2 on the gate 52 is designed such that the maximum angle of the cutting tool 110 is 135°. Figure 14 The angle α of the gate 52 shown is smaller than the angle α of the gate 52 in the first embodiment described above, where the maximum angle of the cutting tool 110 is 125°, and larger than the angle α of the gate 52 in the second embodiment described above, where the maximum angle of the cutting tool 110 is 145°.

[0113] Thus, if it forms Figure 14 and Figure 15 The shape of the gate 52 shown is finished within the range of 25° to 135° relative angle θ of the cutting tool 110. In this way, by setting the maximum angle of the cutting tool 110 to below 135°, interference between the spindle 101 and the rotary table 104 can be avoided when machining the helical groove 40 corresponding to the gate 52 using the five-axis machining center 100.

[0114] (Fourth Implementation)

[0115] like Figure 16As shown, the gate rotor 51 has a gate 52 that engages with the helical groove 40 of the screw rotor 30. The gate 52 has a first sealing line 55 and a second sealing line 56 that contact the side wall surface 41 of the helical groove 40 of the screw rotor 30.

[0116] The first sealing line 55 and the second sealing line 56 are asymmetrical relative to the first imaginary straight line L1, wherein the first imaginary straight line L1 passes through the rotation center O of the gate rotor 51 and the first intermediate position A located between the first sealing line 55 and the second sealing line 56 on the front end side of the gate 52.

[0117] Furthermore, the second imaginary line L2 is inclined at a predetermined angle relative to the first imaginary line L1, wherein the second imaginary line L2 passes through the rotation center O of the gate rotor 51 and the second intermediate position B located between the first sealing line 55 and the second sealing line 56 on the base end side of the gate 52. Let α be the angle between the first imaginary line L1 and the second imaginary line L2.

[0118] like Figure 17 As shown, the central axis of the cutting tool 110 is parallel to the central axis 33 of the screw rotor 30, and the front end of the cutting tool 110 is at... Figure 17 The state of the cutting tool 110 facing downward is set to the case where the relative angle θ between the cutting tool 110 and the central axis 33 of the screw rotor 30 is 0°.

[0119] The maximum angle of the cutting tool 110 when machining the axial end of the screw rotor 30 is related to the shape of the gate 52. Figure 17 In the example shown, the angle α between the first imaginary straight line L1 and the second imaginary straight line L2 on the gate 52 is designed such that the maximum angle of the cutting tool 110 is 120°. Figure 16 The angle α of the gate 52 shown is larger than the angle α of the gate 52 in the first embodiment described above, where the maximum angle of the cutting tool 110 is 125°.

[0120] Thus, if it forms Figure 16 and Figure 17 The shape of the gate 52 shown is finished within the range of 25° to 120° relative angle θ of the cutting tool 110. In this way, by setting the maximum angle of the cutting tool 110 to below 120°, interference between the spindle 101 and the rotary table 104 can be avoided when machining the helical groove 40 corresponding to the gate 52 using the five-axis machining center 100.

[0121] The embodiments and variations have been described above; however, it should be understood that various changes can be made to their form and specific details without departing from the spirit and scope of the claims. Appropriate combinations or substitutions can also be made to the elements involved in the above embodiments, variations, and other embodiments. The terms "first," "second," "third," etc., in the specification and claims are only used to distinguish statements containing these terms and are not intended to limit the number or order of the statements.

[0122] -Industry Applicability-

[0123] In summary, this disclosure is useful for screw compressors and refrigeration devices.

[0124] - Symbol Explanation -

[0125] 1 Refrigeration unit

[0126] 1a refrigerant circuit

[0127] 10-screw compressor

[0128] 30 screw rotor

[0129] 31 First sealing end

[0130] 32 Second sealing end

[0131] 33 central axis

[0132] 40 spiral groove

[0133] 41 sidewalls

[0134] 42 bottom wall

[0135] 51 brake rotor

[0136] 52 gates

[0137] 55 First sealing line

[0138] 56 Second sealing line

[0139] A First Middle Position

[0140] B, second middle position

[0141] L1 First Imaginary Straight Line

[0142] L2 Second Imaginary Straight Line

[0143] O Rotation Center

Claims

1. A screw compressor comprising a screw rotor (30) and a brake rotor (51), the screw rotor (30) having a plurality of helical grooves (40), and the brake rotor (51) having a brake (52) engaging with the helical grooves (40) of the screw rotor (30), characterized in that: The gate (52) has a first sealing line (55) and a second sealing line (56), which are in contact with the side wall (41) of the spiral groove (40) of the screw rotor (30). The first sealing line (55) is located downstream of the second sealing line (56) in the rotation direction of the gate (52). The first sealing line (55) and the second sealing line (56) are asymmetrical with respect to the first imaginary straight line (L1). The first imaginary straight line (L1) passes through the rotation center (O) of the gate rotor (51) and the front end side of the gate (52), at a first intermediate position (A) between the first sealing line (55) and the second sealing line (56). The first imaginary straight line (L1) does not pass through the base end side of the gate (52). The second imaginary straight line (L2) is inclined at a predetermined angle relative to the first imaginary straight line (L1). The second imaginary straight line (L2) passes through the rotation center (O) of the gate rotor (51) and the base end side of the gate (52) at a second intermediate position (B) between the first sealing line (55) and the second sealing line (56). The spiral groove (40) has a shape corresponding to the gate (52). The angle between the first sealing line (55) and the front end of the gate (52) is smaller than the angle between the second sealing line (56) and the front end of the gate (52). Let α be the angle between the first imaginary line (L1) and the second imaginary line (L2). When viewed from the axial direction of the brake rotor (51), the maximum angle between the central axis (33) of the screw rotor (30) and the side wall (41) of the helical groove (40) that contacts the first sealing line (55) decreases as the angle α increases. The maximum angle is related to the shape of the gate, and the maximum angle is less than 145°.

2. The screw compressor according to claim 1, characterized in that: The maximum angle is below 135°.

3. The screw compressor according to claim 2, characterized in that: The maximum angle is below 120°.

4. The screw compressor according to any one of claims 1 to 3, characterized in that: The corner between the bottom wall surface (42) and the side wall surface (41) of the spiral groove (40) is curved.

5. The screw compressor according to any one of claims 1 to 3, characterized in that: A first sealing end (31) and a second sealing end (32) are provided at both axial ends of the screw rotor (30). The spiral groove (40) is formed between the first sealing end (31) and the second sealing end (32).

6. The screw compressor according to claim 4, characterized in that: A first sealing end (31) and a second sealing end (32) are provided at both axial ends of the screw rotor (30). The spiral groove (40) is formed between the first sealing end (31) and the second sealing end (32).

7. A refrigeration device, characterized in that: The refrigeration device includes a screw compressor (10) as described in any one of claims 1 to 6, and a refrigerant circuit (1a) for the flow of refrigerant compressed by the screw compressor (10).

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