Screw compressor and refrigeration device

Abstract

A gate rotor assembly (50) has a gate rotor (51) having a plurality of flat plate-shaped gates (53) engaging with helical grooves (41) of a screw rotor (40), a first support member (56) made of metal having a plurality of first gate support portions (84) supporting each gate (53) from a back surface side of the gate (53), and a second support member (58) made of metal having a plurality of second gate support portions (92) supporting each gate (53) from a surface side of the gate (53).

Description

Technical Field

[0001] The present disclosure relates to a screw compressor and a refrigeration device. Background Art

[0002] Compressors for compressing working fluids are known. Patent Document 1 discloses a screw compressor comprising a screw rotor formed with multiple helical grooves and a gate rotor assembly that rotates as the screw rotor rotates. The gate rotor assembly includes a gate rotor having radial gates that mesh with the helical grooves, and a rotor support member that supports the gate rotor. In a screw compressor, the gate rotors mesh with the helical grooves of the screw rotor, thereby forming compression chambers within the grooves. The surface of the gate rotor faces the compression chamber.

[0003] In the gate rotor assembly described in Patent Document 1, the rotor support member supports the gate rotor from the rear side. This ensures the strength of the gate rotor against pressure acting from the front side toward the rear side during operation of the screw compressor.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2019-007399 Summary of the Invention

[0007] -Technical problem to be solved by the invention-

[0008] During the operation of a screw compressor, it is very rare that a large pressure acts in the opposite direction, that is, from the back side to the front side of the gate rotor. In this case, there is a possibility that the gate rotor cannot withstand the pressure in this direction and may be damaged.

[0009] An object of the present invention is to improve the strength of a screw compressor against pressure generated in a direction opposite to the normal direction during operation.

[0010] -Technical solutions to solve technical problems-

[0011] The first aspect is directed to a screw compressor including a housing 11, a screw rotor 40 housed in the housing 11 and rotated by a drive, and a gate rotor assembly 50 rotated along with the screw rotor 40. The gate rotor assembly 50 includes a gate rotor 51 having a plurality of flat gate plates 53 engaged with helical grooves 41 of the screw rotor 40, a first support member 56 made of metal and having a plurality of first gate supports 84 supporting each of the gate plates 53 from a back surface side of the gate plate 53 and supporting the gate rotor 51 so as to be rotatable, and a second support member 58 made of metal and having a plurality of second gate supports 92 supporting each of the gate plates 53 from a surface side of the gate plate 53.

[0012] In the first aspect, since the gate rotor assembly 50 includes the second support member 58 made of metal and having the second gate supports 92 supporting each of the gate plates 53 from the surface side, each of the gate plates 53 can be reinforced against a pressure acting from the back surface to the surface of each of the gate plates 53 during operation of the screw compressor 10. Thus, the strength against a pressure generated in a direction opposite to a normal direction during operation of the screw compressor 10 can be improved.

[0013] The second aspect is directed to the first aspect, wherein the gate rotor 51 is sandwiched between the first support member 56 and the second support member 58, and each of the gate plates 53 is held by the first support member 56 and the second support member 58 in a state of being able to move slightly in a radial direction and a circumferential direction of the first support member 56.

[0014] Here, in a case where constituent members of the screw compressor 10 are thermally expanded along with operation of the screw compressor 10, the relative positions of the screw rotor 40 and the gate rotor assembly 50 are changed. At this time, the gate rotor 51 is abraded by being pressed against the screw rotor 40 by an excessive force.

[0015] In the second aspect, since the gate rotor 51 is sandwiched by the first support member 56 and the second support member 58, the gate rotor 51 is regulated in movement in a rotational axis direction. On the other hand, since each of the gate plates 53 is held by the first support member 56 and the second support member 58 in a state of being able to move slightly in a radial direction and a circumferential direction of the first support member 56, the gate rotor 51 is able to move in the radial direction and the circumferential direction.

[0016] Therefore, even if the relative position of the screw rotor 40 and the gate rotor assembly 50 is changed due to thermal expansion of the screw compressor 10, the position of the gate rotor 51 is changed following the screw rotor 40 by slightly moving the gates 53 in the radial and circumferential directions, so that the two can normally engage with each other. Thus, it is possible to suppress the wear of the gate rotor 51 accompanying thermal expansion of the constituent members.

[0017] In the third aspect, since the gap G is formed between the inner peripheral surface of the recess 78 of each gate 53 and the outer peripheral surface of the protrusion 93 of the second gate support 92 to surround the entire circumference of the protrusion 93, the gate rotor 51 can move in the radial and circumferential directions.

[0018] In the third aspect, since the gap G is formed between the inner peripheral surface of the recess 78 of each gate 53 and the outer peripheral surface of the protrusion 93 of the second gate support 92 to surround the entire circumference of the protrusion 93, the gate rotor 51 can move in the radial and circumferential directions.

[0019] Therefore, even if the relative position of the screw rotor 40 and the gate rotor assembly 50 is changed due to thermal expansion of the screw compressor 10, the position of the gate rotor 51 is changed following the screw rotor 40 by the presence of the gap G formed between the protrusion 93 and the recess 78, so that the two can normally engage with each other. Thus, it is possible to suppress the wear of the gate rotor 51 accompanying thermal expansion of the constituent members.

[0020] In the fourth aspect, since the gate rotor 51 is divided into a plurality of gate blocks 70, each gate block 70 can easily move depending on the degree of thermal expansion.

[0021] In the fourth aspect, since the gate rotor 51 is divided into a plurality of gate blocks 70, each gate block 70 can easily move depending on the degree of thermal expansion.

[0022] In the fifth aspect, since each gate block 70 is pressed against the screw rotor 40 by the elastic body E, it is possible to suppress the gap formed between the helical groove 41 and the radial outer end surface of each gate 53.

[0023] In the fifth aspect, since each gate block 70 is pressed against the screw rotor 40 by the elastic body E, it is possible to suppress the gap formed between the helical groove 41 and the radial outer end surface of each gate 53.

[0024] In the sixth aspect, since the width of each gate 53 widens from the radially inner side toward the radially outer side, the gate rotor 51 is less likely to be ejected from the helical groove 41 of the screw rotor 40.

[0025] In the sixth aspect, since the width of each gate 53 widens from the radially inner side toward the radially outer side, the gate rotor 51 is less likely to be ejected from the helical groove 41 of the screw rotor 40.

[0026] The seventh aspect is directed to a refrigeration device including the screw compressor 10 of any one of the first to sixth aspects.

[0027] In the seventh aspect, it is possible to provide a refrigeration device 1 including the screw compressor 10 that improves the strength against the pressure generated on the surface side in the reverse direction to the usual direction during the operation of the screw compressor 10. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 is a piping system diagram of a refrigeration device of an embodiment;

[0029] Figure 2 is a longitudinal sectional view showing a brief structure of a screw compressor;

[0030] Figure 3 is Figure 2 a III-III line view sectional view of

[0031] Figure 4 is a perspective view showing an engaged state of a screw rotor and a gate rotor assembly;

[0032] Figure 5 is a plan view of a gate rotor assembly;

[0033] Figure 6 is a plan view showing a state in which a gate rotor has been assembled on a first support member;

[0034] Figure 7 is a perspective view of a gate block;

[0035] Figure 8 is an enlarged plan view of a gate block of a gate rotor assembly;

[0036] Figure 9 is Figure 8 a IX-IX line view sectional view of

[0037] Figure 10 is a view corresponding to Figure 5 of a first modification example;

[0038] Figure 11 is a view corresponding to Figure 8 of a second modification example;

[0039] Figure 12 is a plan view of a gate rotor of a fourth modification. Figure 5

[0040] Figure 13 is a plan view of a gate rotor of a fourth modification. DETAILED DESCRIPTION

[0041] Hereinafter, embodiments of the present disclosure will be explained in detail with reference to the drawings. Note that the present disclosure is not limited to the embodiments shown below, and various modifications can be made without departing from the technical idea of the present disclosure. The drawings are used to schematically illustrate the present disclosure, and the dimensions, ratios or amounts are sometimes exaggerated or simplified for the sake of easy understanding.

[0042] (Embodiment)

[0043] (1) Outline of refrigerating apparatus

[0044] As shown in FIG. 1, a screw compressor 10 is provided in a refrigerating apparatus 1. The refrigerating apparatus 1 has a refrigerant circuit la filled with a refrigerant. The refrigerant circuit la has the screw compressor 10, a heat radiator 3, a pressure reducing mechanism 4, and an evaporator 5. The pressure reducing mechanism 4 is an expansion valve. The refrigerant circuit la performs a vapor compression type refrigeration cycle. Figure 1 In the refrigeration cycle, the refrigerant compressed by the screw compressor 10 is heat radiated to air in the heat radiator 3. The heat radiated refrigerant is pressure reduced by the pressure reducing mechanism 4, and evaporated in the evaporator 5. The evaporated refrigerant is sucked into the screw compressor 10.

[0045] The refrigerating apparatus 1 is an air conditioning apparatus. The air conditioning apparatus can also be a refrigeration-only machine, a heating-only machine, or an air conditioning apparatus that switches between refrigeration and heating. In this case, the air conditioning apparatus has a switching mechanism (for example, a four-way reversing valve) that switches the direction of the refrigerant cycle. The refrigerating apparatus 1 can also be a water heater, a cooling unit, a cooling apparatus for air in a cold storage, or the like. The cooling apparatus cools air in the interior of a refrigerated warehouse, a freezer, a container, or the like.

[0046] (2) Screw compressor

[0047] The screw compressor 10 of the present embodiment compresses the sucked low-pressure gaseous refrigerant, and discharges high-pressure gaseous refrigerant. As shown in FIG. 2, the screw compressor 10 of the present embodiment is a single screw compressor having one screw rotor 40. Further, the screw compressor 10 of the present embodiment performs single-stage compression.

[0048] Figures 2 to 4 (2-1) Overall structure

[0049] (2-1) Overall structure

[0050] ​​As shown in Figure 2 and Figure 3 , the screw compressor 10 includes a housing 11, a motor 17, a drive shaft 18, and a compression mechanism 19. The motor 17, the drive shaft 18, and the compression mechanism 19 are housed in the housing 11. The compression mechanism 19 includes one screw rotor 40 and two gate rotor assemblies 50.

[0051] (2-1-1) Housing

[0052] As shown in Figure 2 , the housing 11 is formed in a cylindrical shape with both ends closed. The housing 11 is arranged in a posture in which the length direction thereof is substantially horizontal. The housing 11 includes a main body portion 12 and a cylinder portion 16. The main body portion 12 is formed in a transversely long cylindrical shape with both ends closed. The cylinder portion 16 is formed in a substantially cylindrical shape and is arranged near the center in the length direction of the main body portion 12. The cylinder portion 16 is formed integrally with the main body portion 12. The inner peripheral surface of the cylinder portion 16 is a cylindrical surface.

[0053] In the main body portion 12, a suction port 14 and a discharge port 15 are formed. The suction port 14 is formed in the upper portion of the left end portion of the housing 11. The discharge port 15 is formed in the upper portion of the right end portion of the housing 11. Figure 2 Figure 2

[0054] The internal space of the main body portion 12 is partitioned into a low-pressure space S1 and a high-pressure space S2. The low-pressure space S1 is formed at a position close to one end of the main body portion 12 with the cylinder portion 16 as a reference, and communicates with the suction port 14. The high-pressure space S2 is formed at a position close to the other end of the main body portion 12 with the cylinder portion 16 as a reference, and communicates with the discharge port 15.

[0055] (2-1-2) Motor, drive shaft

[0056] The motor 17 is arranged in the low-pressure space S1. The drive shaft 18 links the motor 17 and the screw rotor 40. The motor 17 drives the screw rotor 40 to rotate.

[0057] (2-1-3) Screw rotor

[0058] As shown in Figure 2 , the screw rotor 40 is rotatably housed in the cylinder portion 16. As shown in Figure 4 , the screw rotor 40 is a cylindrical member made of metal. The outer peripheral surface of the screw rotor 40 is in sliding contact with the inner peripheral surface of the cylinder portion 16 via an oil film of lubricating oil. The front side of the screw rotor 40, Figure 4 the low-pressure space S1 side, Figure 4 the high-pressure space S2 side.

[0059] ​​A plurality of (six in the present embodiment) helical grooves 41 are formed in the outer peripheral portion of the screw rotor 40. Each helical groove 41 is a groove that extends in a helical shape in the circumferential direction and the axial direction of the screw rotor 40. The six helical grooves 41 are arranged at equal angles in the circumferential direction of the screw rotor 40. In each helical groove 41 of the screw rotor 40, the end of the drive shaft 18 on the front end side (the end on the rear end side in the case of the Figure 4 end on the front end side in the case of the Figure 4 end on the rear end side in the case of the

[0060] The end portion of the suction side (the low-pressure space S1 side) of the screw rotor 40 is formed in a tapered shape. In the case of the screw rotor 40 shown in Fig. 1, the end face of the suction side of the screw rotor 40 is formed in a tapered shape. In the case of the screw rotor 40 shown in Fig. 2, the end face of the suction side of the screw rotor 40 is formed in a tapered shape. Figure 4

[0061] (2-1-4) Gate Rotor Assembly

[0062] As shown in Fig. 3, each gate rotor assembly 50 is rotatably attached to the main body portion 12 of the housing 11. Each gate rotor assembly 50 includes a gate rotor 51, a first support member 56, and a second support member 58. In the gate rotor assembly 50, the first support member 56, the gate rotor 51, and the second support member 58 are stacked in this order. The gate rotor 51 is held by the first support member 56 and the second support member 58. Figure 3 The gate rotor 51 is a circular flat plate-shaped member made of resin. As shown in Fig. 4, a plurality of (ten in the present embodiment) gates 53 are provided on the gate rotor 51 in a radial manner. Each gate 53 is a substantially rectangular flat plate-shaped portion. In the present embodiment, the gate rotor 51 is composed of a plurality of gate blocks 70 each of which is formed with the gates 53 independently from each other. The detailed structure of the gate rotor 51 will be described later.

[0063] Figure 4 The gates 53 enter the helical grooves 41 of the screw rotor 40, and the compression chambers 32 are formed by the gates 53 sliding against the wall surfaces of the helical grooves 41. The surface 61 of the gate rotor 51 is the surface on the side of the compression chambers 32. The back surface 62 of the gate rotor 51 is the surface on the opposite side from the surface 61.

[0064] The first support member 56 is a metal member. The first support member 56 is arranged so as to be in contact with the back surface 62 of the gate rotor 51, and supports the gate rotor 51. The second support member 58 is a flat plate-shaped metal member. The second support member 58 is arranged so as to be in contact with the surface 61 of the gate rotor 51, and supports the gate rotor 51. The detailed structures of the first support member 56 and the second support member 58 will be described later.

[0065] The first support member 56 is a metal member. The first support member 56 is arranged so as to be in contact with the back surface 62 of the gate rotor 51, and supports the gate rotor 51. The second support member 58 is a flat plate-shaped metal member. The second support member 58 is arranged so as to be in contact with the surface 61 of the gate rotor 51, and supports the gate rotor 51. The detailed structures of the first support member 56 and the second support member 58 will be described later.

[0066] ​​In Figure 3 One shutter rotor chamber 21 is formed on each of the left and right sides of the cylinder portion 16. One shutter rotor assembly 50 is housed in each shutter rotor chamber 21. Each shutter rotor chamber 21 communicates with the low-pressure space S1.

[0067] Specifically, a bearing shell 22 is provided in each shutter rotor chamber 21. The bearing shell 22 is a cylindrical member made of metal. The bearing shell 22 is fixed to the main body portion 12 of the housing 11. The shutter rotor assembly 50 is rotatably supported by a bearing in the bearing shell 22.

[0068] In Figure 3 The shutter rotor assembly 50 arranged on the right side of the screw rotor 40 has the surface 61 of the shutter rotor 51 facing upward. In Figure 3 The shutter rotor assembly 50 arranged on the left side of the screw rotor 40 has the surface 61 of the shutter rotor 51 facing downward. The two shutter rotor assemblies 50 are arranged in mutually axis-symmetrical poses with respect to the rotation axis of the screw rotor 40. The rotation axis of each shutter rotor assembly 50 extends in a plane perpendicular to the rotation axis of the screw rotor 40.

[0069] The shutter rotor assembly 50 is arranged so as to penetrate the cylinder portion 16. The shutter rotor assembly 50 rotates along with the rotation of the screw rotor 40. Also, along with the rotation of the shutter rotor assembly 50, the shutter 53 of the shutter rotor 51 enters the helical groove 41 of the screw rotor 40 and engages with the screw rotor 40.

[0070] (2-1-5) Compression Chamber

[0071] As Figure 2 and Figure 3 In the screw compressor 10, a compression chamber 32 (hereinafter also referred to as a high-pressure chamber) is formed by the screw rotor 40, the shutter rotor 51, and the cylinder portion 16 of the housing 11. The compression chamber 32 is a closed space surrounded by the wall surface of the helical groove 41 of the screw rotor 40, the surface 61 of the shutter 53 of the shutter rotor 51, and the inner peripheral surface of the cylinder portion 16. Note that, in the helical groove 41, the space on the opposite side of the compression chamber 32 across the shutter 53 becomes a low-pressure chamber. The low-pressure chamber is a space having a lower pressure than the compression chamber 32.

[0072] (2-2) Detailed Structure of Shutter Rotor Assembly

[0073] The detailed structure of the shutter rotor assembly 50 will be described in detail with reference to Figures 3 to 9 The detailed structure of the shutter rotor assembly 50 will be described in detail with reference to

[0074] (2-2-1) Gate rotor

[0075] like Figure 6 As shown, the gate rotor 51 is composed of a plurality (ten in this embodiment) of radially extending gate blocks 70. The gate blocks 70 include a first gate block 70a having a gate 53 and a second gate block 70b having a gate 53. Each gate block 70 is made of resin and is manufactured by injection molding. Alternatively, each gate block 70 may be machined after being formed by injection molding.

[0076] Each brake block 70 of the present embodiment includes a base portion 71 and a brake portion 72 .

[0077] The base portion 71 is a portion of the gate shoe 70 that is close to the rotation axis of the gate rotor assembly 50. Each base portion 71 is formed in a substantially trapezoidal shape so that side surfaces of adjacent base portions 71 come into surface contact with each other.

[0078] The gate portion (72) extends radially outward from the outer periphery of the base portion (71). The gate portion (72) constitutes the gate (53) of the gate rotor (51). The gate portion (72) is formed in a generally rectangular shape to engage with the spiral groove (41) of the screw rotor (40). In this embodiment, the gate portion (72) extends radially inward toward the radially outward side of the gate rotor (51), and the width of the gate portion (72) is generally constant.

[0079] like Figure 7 As shown, the gate portion 72 is composed of a bottom portion 74, a radially outer end wall portion 75, a front side wall portion 76, and a rear side wall portion 77. The bottom portion 74 is a planar portion extending radially outward from the base portion 71. Figure 9 As shown, the thickness of the bottom portion 74 is thinner than the thickness of the base portion 71. In other words, the bottom portion 74 is lower than the base portion 71.

[0080] The radially outer end wall portion 75 is provided at the radially outer end portion of the bottom surface portion 74. The radially outer end wall portion 75 extends from the bottom surface portion 74 toward the second support member 58 side ( Figure 9 The front wall portion 76 is provided at the side edge of the bottom surface portion 74 on the front side in the rotation direction R of the gate rotor 51. The front wall portion 76 protrudes from the bottom surface portion 74 toward the second support member 58. The rear wall portion 77 is provided at the side edge of the bottom surface portion 74 on the rear side in the rotation direction R of the gate rotor 51. The rear wall portion 77 protrudes from the bottom surface portion 74 toward the second support member 58.

[0081] The gate portion 72 has a recessed portion 78. The recessed portion 78 is a portion surrounded by the gate portion 72's bottom portion 74, radially outer end wall portion 75, front side wall portion 76, and rear side wall portion 77. The bottom of the recessed portion 78 is formed into a substantially rectangular shape. The recessed portion 78 is recessed toward the first support member 56.

[0082] (2-2-2) First Supporting Member

[0083] As shown in Figure 3 and Figure 4 , the first support member 56 has a circular plate portion 81, a first shaft portion 82, a second shaft portion 83, and a plurality of first gate support portions 84.

[0084] The circular plate portion 81 is formed as a slightly thick circular plate-like portion. The first shaft portion 82 is formed as a circular bar-like portion. The first shaft portion 82 is provided on the back surface side of the circular plate portion 81. The first shaft portion 82 extends from the central portion of the circular plate portion 81. The axis of the first shaft portion 82 coincides with the axis of the circular plate portion 81.

[0085] The second shaft portion 83 is formed as a cylindrical portion. The second shaft portion 83 is provided on the surface side of the circular plate portion 81. The second shaft portion 83 extends from the central portion of the circular plate portion 81. The axis of the second shaft portion 83 coincides with the axis of the first shaft portion 82. The axis of the second shaft portion 83 coincides with the axis of the circular plate portion 81. The cross-sectional area of the second shaft portion 83 is smaller than that of the first shaft portion 82. The gate rotor 51 and the second support member 58 are fitted in the second shaft portion 83. Each gate block 70 of the gate rotor 51 is arranged so as to surround the second shaft portion 83.

[0086] A groove, not shown, is formed in the outer peripheral surface of the second shaft portion 83 at a position close to the compression chamber 32. Specifically, in the second shaft portion 83, the groove is formed on the side of the compression chamber 32 further than the position at which the second support member 58 is arranged. The groove is formed around the entire circumference of the second shaft portion 83. A retainer (for example, a snap ring) is fitted in the groove. By fitting the retainer in the groove, movement of each gate block 70 and the second support member 58 in the axial direction is restricted. In other words, by restricting the movement of the second support member 58 in the axial direction by the retainer, the movement of each gate block 70 sandwiched between the first support member 56 and the second support member 58 in the axial direction is restricted.

[0087] The first support member 56 has the same number of first gate support portions 84 as the number of gates 53 of the gate rotor 51 (ten in this embodiment). The first gate support portions 84 are portions that extend radially outward from the outer peripheral portion of the circular plate portion 81. Each first gate support portion 84 extends along the back surface of the corresponding gate portion 72.

[0088] As shown in Figure 9 , each first gate support portion 84 covers substantially the entire back surface of each gate portion 72. Each first gate support portion 84 supports the corresponding gate portion 72 from the back surface side in a state of contact with the back surface of the corresponding gate portion 72. The cross-sectional shape of each first gate support portion 84 perpendicular to the extending direction is formed in a substantially triangular shape.

[0089] Because each gate portion (72) corresponding to the first gate support portion (84) is supported from the rear side by each first gate support portion (84), strength can be ensured against the pressure acting from the front surface (61) toward the rear surface (62) of the gate rotor (51) caused by the compression of the refrigerant in the compression chamber (32) during operation of the screw compressor (10).

[0090] (2-2-3) Second supporting member

[0091] like Figure 4 and Figure 5 As shown, the second support member 58 has a circular ring portion 91 and a plurality of second gate support portions 92 .

[0092] The annular portion 91 is an annular portion. The second shaft portion 83 of the first support member 56 is inserted into a hole formed in the center of the annular portion 91. The second support member 58 includes the same number of second gate support portions 92 as the gates 53 of the gate rotor 51 (ten in this embodiment). The second gate support portions 92 extend radially outward from the outer periphery of the annular portion 91. Each second gate support portion 92 extends along the surface of the corresponding gate portion 72. Each second gate support portion 92 supports the corresponding gate portion 72 from the surface side while in contact with the surface.

[0093] Because each second gate support portion (92) supports the corresponding gate portion (72) from the front side, it is possible to enhance the strength against pressure from the rear surface (62) of the gate rotor (51), which rarely occurs during operation of the screw compressor (10). This reduces damage to the gate rotor (51) caused by pressure in the opposite direction, that is, from the rear surface (62) toward the front surface (61) of the gate rotor (51).

[0094] like Figure 9 As shown, the second gate support portion 92 has a protrusion 93. The protrusion 93 is a portion that protrudes toward the gate portion 72. In other words, the thickness of the second gate support portion 92 is thicker than the thickness of the annular portion 91. Figure 8 As shown, the protrusion 93 is formed in a substantially rectangular shape. The protrusion 93 engages with the recess 78 of the gate portion 72. The protrusion 93 is in surface contact with the bottom of the recess 78. The area of ​​the protrusion 93 is smaller than the area of ​​the bottom of the recess 78.

[0095] In this manner, since the protrusion 93 engages with the recess 78 of the gate portion 72 , it is possible to restrict the gate shoe 70 from moving significantly in the circumferential and radial directions.

[0096] (2-2-4) Gap

[0097] like Figure 8As shown, a slight gap G is formed between the inner peripheral surface of the recess 78 and the outer peripheral surface of the protruding portion 93 to surround the entire periphery of the protruding portion 93. In detail, the gap G is composed of a first gap Gl, a second gap G2, a third gap G3, and a fourth gap G4.

[0098] The first gap Gl is formed between the inner side surface of the front side wall portion 76 and the front side surface of the protruding portion 93. The second gap G2 is formed between the inner side surface of the rear side wall portion 77 and the rear side surface of the protruding portion 93. The third gap G3 is formed between the inner side surface of the radially outer end wall portion 75 and the radially outer side surface of the protruding portion 93. The fourth gap G4 is formed between the radially outer end surface of the base portion 71 and the base end side surface of the protruding portion 93.

[0099] Here, during operation of the screw compressor 10, the components constituting the screw compressor 10 thermally expand due to the compression heat generated along with compression of the refrigerant. In this case, as the main body portion 12 of the housing 11 thermally expands, the position of the bearing housing 22 that supports the gate rotor assembly 50 changes. As the position of the bearing housing 22 changes, the position of the gate rotor 51 also changes, and the relative position of the screw rotor 40 and the gate rotor 51 is thereby shifted. When the relative position of the screw rotor 40 and the gate rotor 51 is shifted, the gate rotor 51 made of resin is excessively pressed against the screw rotor 40, which causes abrasion. If the gate rotor 51 is abraded, the refrigerant leaks out of the compression chamber 32, which results in a decrease in performance of the screw compressor 10.

[0100] In contrast, in the gate rotor assembly 50 of the present embodiment, the gate rotor 51 is in contact with and sandwiched by the first support member 56 and the second support member 58, and thus movement of the gate rotor 51 in the axial direction is restricted. On the other hand, since the gap G is formed between the inner peripheral surface of the recess 78 in the gate portion 72 of each gate block 70 and the outer peripheral surface of the protruding portion 93 of the second support member 58 to surround the entire periphery of the protruding portion 93, each gate block 70 is configured to be slightly movable in the circumferential and radial directions on the surface of the first support member 56. In other words, the gap G allows the position of the gate rotor 51 to shift due to thermal expansion. In this way, even if the relative position of the gate rotor 51 with respect to the screw rotor 40 changes due to thermal expansion, the position of the gate rotor 51 follows the screw rotor 40 due to the presence of the gap G, and thus the gate rotor 51 and the screw rotor 40 can normally mesh with each other. As a result, abrasion of the gate rotor 51 can be suppressed.

[0101] (3) Operation

[0102] In the screw compressor 10, the screw rotor 40 is driven by the motor 17. When the screw rotor 40 rotates, the gate rotor assembly 50 engaged with the screw rotor 40 rotates. When the gate rotor assembly 50 rotates, the gates 53 of the gate rotor 51 enter the spiral grooves 41 of the screw rotor 40 and relatively move from the suction side end 42 of the entered spiral groove 41 toward the discharge side end 43. As a result, the volume of the compression chamber 32 is gradually reduced, and the refrigerant in the compression chamber 32 is compressed.

[0103] In the screw compressor 10, the low-pressure gaseous refrigerant flowing out from the evaporator 5 is sucked from the suction port 14. The gaseous refrigerant flowing into the low-pressure space S1 through the suction port 14 flows into the compression chamber 32 and is compressed. The compressed gaseous refrigerant is discharged toward the high-pressure space S2. The refrigerant flowing into the high-pressure space S2 is discharged toward the outside of the screw compressor 10 through the discharge port 15. The high-pressure gaseous refrigerant discharged from the discharge port 15 flows toward the heat radiator 3.

[0104] (4) Features

[0105] (4-1)

[0106] The gate rotor assembly 50 has a resin-made gate rotor 51 in which a plurality of flat plate-shaped gates 53 engaged with the spiral grooves 41 of the screw rotor 40 are formed in a radial manner, a metal-made first support member 56 having a plurality of first gate support portions 84 that support each gate 53 from the back surface side of the gate 53 to support the gate rotor 51 so as to be rotatable, and a metal-made second support member 58 having a plurality of second gate support portions 92 that support each gate 53 from the surface side of the gate 53.

[0107] Since the gate rotor assembly 50 includes the metal-made second support member 58 having the second gate support portions 92 that support each gate 53 from the surface side, each gate 53 can be reinforced against the pressure acting from the back surface toward the surface of each gate 53 during the operation of the screw compressor 10. Thus, the strength against the pressure generated in the reverse direction to the normal direction during the operation of the screw compressor 10 can be improved.

[0108] (4-2)

[0109] The gate rotor 51 is sandwiched between the first support member 56 and the second support member 58. Each second gate support portion 92 of the second support member 58 has a protruding portion 93 that protrudes toward the gate 53. The plurality of gates 53 respectively have recessed portions 78 that engage with the protruding portions 93 of the second gate support portions 92. A gap G is formed between the inner peripheral surface of the recessed portion 78 and the outer peripheral surface of the protruding portion 93 to surround the entire circumference of the protruding portion 93.

[0110] Since the gate rotor 51 is sandwiched by the first support member 56 and the second support member 58, movement of the gate rotor 51 in the rotational axis direction is restricted. On the other hand, since a gap G is formed between the inner peripheral surface of the recess 78 of each gate 53 and the outer peripheral surface of the protruding portion 93 of the second gate support portion 92 so as to surround the entire circumference of the protruding portion 93, the gate rotor 51 is able to move in the radial direction and the circumferential direction.

[0111] Therefore, even if the relative position of the screw rotor 40 and the gate rotor assembly 50 changes due to thermal expansion of the screw compressor 10, the position of the gate rotor 51 changes following the screw rotor 40 due to the existence of the gap G, and thus the two are able to normally mesh. As a result, it is possible to suppress wear of the gate rotor 51 accompanying thermal expansion.

[0112] (4-3)

[0113] The gate rotor 51 has a plurality of gate blocks 70 each having one gate 53. In this way, since the gate rotor 51 is divided into a plurality of gate blocks 70, each gate block 70 is able to be easily moved according to the degree of thermal expansion.

[0114] By dividing the gate rotor 51 into a plurality of gate blocks 70, each gate block 70 is able to be manufactured by injection molding, and thus it is possible to reduce manufacturing costs.

[0115] (4-4)

[0116] The gate rotor 51 is composed of resin. As a result, it is possible to suppress burn of a sliding portion at the time of meshing with the screw rotor 40.

[0117] (4-5)

[0118] The gate rotor 51 is sandwiched between the first support member 56 and the second support member 58. Each gate 53 is held by the first support member 56 and the second support member 58 in a state in which it is able to move slightly in the radial direction and the circumferential direction of the first support member 56.

[0119] Here, in a case in which the constituent members of the screw compressor 10 have undergone thermal expansion as a result of operation of the screw compressor 10, the relative position of the screw rotor 40 and the gate rotor assembly 50 changes. At this time, the gate rotor 51 is worn by being pressed against the screw rotor 40 by excess force.

[0120] Since the gate rotor 51 is sandwiched by the first support member 56 and the second support member 58, movement of the gate rotor 51 in the rotational axis direction is restricted. On the other hand, since each gate 53 is held by the first support member 56 and the second support member 58 in a state in which it is able to move slightly in the radial direction and the circumferential direction of the first support member 56, the gate rotor 51 is able to move in the radial direction and the circumferential direction.

[0121] Therefore, even if the relative position of the screw rotor 40 and the gate rotor assembly 50 is changed due to thermal expansion of the screw compressor 10, the position of the gate rotor 51 is changed following the screw rotor 40 by slightly moving the gates 53 in the radial and circumferential directions, so the two can normally engage with each other. Thus, it is possible to suppress the wear of the gate rotor 51 accompanying thermal expansion of the constituent members.

[0122] (5) Modification

[0123] The above-described embodiment can also be modified as follows. Note that in the following description, the differences from the above-described embodiment are explained in principle.

[0124] (5-1) First Modification

[0125] The gate rotor assembly 50 of the above-described embodiment can also have an elastic body E that presses each gate block 70 against the screw rotor 40. Specifically, as shown in FIG. 8, the elastic body E is arranged between the base end portion of the base portion 71 of each gate block 70 and the second shaft portion 83 of the first support member 56. In this modification, the elastic body E is a coil spring. The coil spring E presses each gate block 70 toward the radially outer side. The elastic body E can also be a rubber material. Figure 10

[0126] Each gate block 70 of the above-described embodiment is configured to be able to slightly move in the circumferential and radial directions on the surface of the first support member 56. Therefore, in the case where the centrifugal force generated by the rotation of the screw compressor 10 does not sufficiently act on each gate block 70, a gap is formed between the radially outer end surface of each gate block 70 and the helical groove 41 of the screw rotor 40.

[0127] Thus, in this modification, the gate rotor assembly 50 has an elastic body E that presses each gate block 70 against the screw rotor 40, so it is possible to suppress the formation of a gap between the radially outer end surface of each gate block 70 and the helical groove 41 of the screw rotor 40.

[0128] (5-2) Second Modification

[0129] As shown in FIG. 9, the gate portion 72 of each gate block 70 of the above-described embodiment can also widen in width from the radially inner side of the gate rotor 51 toward the radially outer side. In other words, the gate portion 72 can also be a sector shape. Figure 11

[0130] ​​In the above embodiment, as described in the first modification, in a case where the centrifugal force acting on each gate block 70 is insufficient, a gap can be formed between the radially outer end surface of each gate block 70 and the spiral groove 41 of the screw rotor 40. Thus, in the present modification, by making the gate portion 72 fan-shaped, it is possible to suppress the escape of each gate block 70 from the spiral groove 41 when the gate rotor 51 is engaged with the spiral groove 41 of the screw rotor 40.

[0131] (5-3) Third Modification

[0132] Each gate block 70 of the above embodiment can also have a plurality of gate portions 72. Specifically, for example, as shown in FIG. 10, the gate rotor 51 includes a first gate block 70a having one base portion 71 and two gate portions 72 and a second gate block 70b having one base portion 71 and three gate portions 72. As in the above embodiment, in the present modification, it is possible to obtain the effect that each gate block 70 easily moves according to the degree of thermal expansion. Figure 12

[0133] (5-4) Fourth Modification

[0134] As shown in FIG. 11, the gate rotor 51 of the above embodiment can also not be divided into a plurality of gate blocks 70, but can be formed in one piece. In the present modification, too, since a gap G is formed between the recessed portion 78 of the gate portion 72 and the protruding portion 93 of the second gate support portion 92, it is possible to suppress the wear of the gate rotor 51 due to thermal expansion. Note that, in the present modification, an example in which 11 gates 53 are provided in the gate rotor 51 is shown. Figure 13 Figure 13

[0135] (5-5) Fifth Modification

[0136] The gate rotor 51 of the above embodiment can also be provided in a screw compressor that performs two-stage compression. In a screw compressor that performs two-stage compression, for example, the compression chamber 32 on the lower side of the screw rotor 40 is defined as a first compression chamber, and the compression chamber 32 on the upper side of the screw rotor 40 is defined as a second compression chamber. Refrigerant that has flowed into the low-pressure space S1 through the suction port 14 flows into the first compression chamber and is compressed therein. Refrigerant that has been compressed in the first compression chamber and ejected therefrom flows into the second compression chamber through a passage formed in the housing 11. Refrigerant that has flowed into the second compression chamber is compressed and ejected toward the high-pressure space S2.

[0137] (5-6) Sixth Modification

[0138] The gate rotor 51 of the above embodiment is composed of resin, but can also be composed of a material other than resin. For example, the gate rotor 51 can also be composed of metal.

[0139] (5-7) Seventh Modification

[0140] ​​​The gap G of the gate rotor assembly 50 of the above embodiment can also be formed between the recess formed in the second gate support portion 92 and the protrusion formed in the gate portion 72. In other words, in this modification, the members that form the recess and the protrusion can be reversed from the above embodiment.

[0141] In this modification as well, as in the above embodiment, the gap G is formed between the inner peripheral surface of the recess of each second gate support portion 92 and the outer peripheral surface of the protrusion of the gate portion 72 to surround the entire circumference of the protrusion, so the gate rotor 51 is able to move in the radial and circumferential directions.

[0142] Therefore, even if the relative positions of the screw rotor 40 and the gate rotor assembly 50 change due to thermal expansion of the screw compressor 10, the position of the gate rotor 51 will change in accordance with the screw rotor 40 due to the presence of the gap G, so the two are able to properly mesh. This makes it possible to suppress wear of the gate rotor 51 accompanying thermal expansion of the constituent members.

[0143] The above embodiments and modifications have been described, but it should be understood that various changes can be made to the configurations and specific details thereof without departing from the spirit and scope of the claims. Furthermore, the elements involved in the above embodiments, modifications, and other embodiments can be appropriately combined or replaced.

[0144] The words "first", "second", "third", and the like used above are merely used to distinguish the statements containing the words, and do not limit the number or order of the statements.

[0145] - Industrial Applicability -

[0146] In summary, the present disclosure is useful for screw compressors and refrigeration devices.

[0147] - Symbol Explanation -

[0148] 1 Refrigeration Device

[0149] 10 Screw Compressor

[0150] 11 Housing

[0151] 40 Screw Rotor

[0152] 41 Spiral Groove

[0153] 50 Gate Rotor Assembly

[0154] 51 Gate Rotor

[0155] 53 Gate

[0156] 56 First Support Member

[0157] 58 Second Support Member

[0158] 70a first gate block

[0159] 70b second gate block

[0160] 78 recess

[0161] 84 first gate support portion

[0162] 92 second gate support portion

[0163] 93 protrusion

[0164] E coil spring (elastic body)

[0165] G gap

Claims

1. A screw compressor comprising a housing (11), a screw rotor (40) housed in the housing (11) and driven to rotate, and a gate rotor assembly (50) that rotates in conjunction with the rotation of the screw rotor (40), characterized in that: the gate rotor assembly (50) has a gate rotor (51), a first support member (56) made of metal, and a second support member (58) made of metal, the gate rotor (51) has a plurality of flat plate-shaped gates (53) that mesh with helical grooves (41) of the screw rotor (40), the first support member (56) has a plurality of first gate supports (84) that support each of the gates (53) from a back surface side of the gate (53) and rotatably supports the gate rotor (51), the second support member (58) has a circular ring portion (91) formed in a circular ring shape and a plurality of second gate supports (92) that extend radially outward from an outer peripheral portion of the circular ring portion (91) and support each of the gates (53) from a surface side of the gate (53), recessed portions (78) into which the corresponding second gate supports (92) are fitted are formed in each of the gates (53), each of the second gate supports (92) supports the corresponding gate (53) so as to reinforce the gate (53) against a pressure acting from a back surface toward a surface of the gate (53), and the first support member (56) and the second support member (58) hold the gate rotor (51) therebetween.

2. The screw compressor according to claim 1, characterized in that: each of the gates (53) is held by the first support member (56) and the second support member (58) in a state of being able to slightly move in a radial direction and a circumferential direction of the first support member (56).

3. The screw compressor according to claim 2, characterized in that: the gate rotor (51) includes a first gate block (70a) having one or more of the gates (53) and a second gate block (70b) having one or more of the gates (53).

4. The screw compressor according to claim 3, characterized in that: the gate rotor assembly (50) further has an elastic body (E) that presses the first gate block (70a) and the second gate block (70b) against the screw rotor (40), respectively.

5. The screw compressor according to claim 3, characterized in that: the gates (53) of the first gate block (70a) and the second gate block (70b), respectively, widen in width from a radially inner side toward a radially outer side of the gate rotor (51).

6. A screw compressor comprising a housing (11), a screw rotor (40) housed in the housing (11) and driven to rotate, and a gate rotor assembly (50) that rotates in conjunction with the rotation of the screw rotor (40), characterized in that: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The gate rotor assembly (50) has a gate rotor (51), a first support member (56) made of metal, and a second support member (58) made of metal, The gate rotor (51) has a plurality of flat plate-shaped gates (53) that engage with the helical grooves (41) of the screw rotor (40), The first support member (56) has a plurality of first gate support portions (84) that support each of the gates (53) from the back surface side of the gate (53), and supports the gate rotor (51) so as to be rotatable, The second support member (58) has a plurality of second gate support portions (92) that support each of the gates (53) from the surface side of the gate (53), The gate rotor (51) is sandwiched between the first support member (56) and the second support member (58), Each of the gates (53) is held by the first support member (56) and the second support member (58) in a state of being able to move slightly in the radial direction and the circumferential direction of the first support member (56), Each of the second gate support portions (92) of the second support member (58) has a protruding portion (93) that protrudes toward the gate (53), A plurality of the gates (53) respectively have recessed portions (78) that engage with the protruding portions (93) of the second gate support portions (92), A gap (G) is formed between the inner peripheral surface of the recessed portion (78) and the outer peripheral surface of the protruding portion (93) so as to surround the entire circumference of the protruding portion (93).

7. A refrigeration apparatus characterized by comprising: A screw compressor comprising the gate rotor assembly according to any one of claims 1 to 6.

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