Screw compressor

Abstract

A screw compressor includes a screw rotor, a gate rotor, and a casing. The screw rotor, the gate rotor, and the casing form a compression chamber for compressing a fluid. A casing-side discharge port is formed on a casing outer wall portion in the casing on a radially outer peripheral side. A discharge port is formed on a portion of the casing facing the compression chamber. The discharge port includes a front end portion on an axially front side and a rear end portion on an axially rear side. The casing-side discharge port is located in the axial direction between a front position that is a distance equal to a gate radius away from the front end portion toward the front side and a rear position that is a distance equal to the gate radius away from the second end portion toward the rear side.

Description

Technical Field

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

[0002] For example, as shown in Patent Document 1, various technologies related to screw compressors are disclosed.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Publication No. 2014-025435 Summary of the Invention

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

[0007] This screw compressor includes a screw rotor, a guillotine rotor, and a housing. The screw rotor extends axially and has screw grooves on its outer periphery. A guillotine rotor has a guillotine. The guillotine's guillotine engages with the screw grooves of the screw rotor. The housing holds the screw rotor in place so that it can rotate and covers the screw rotor from its outer periphery.

[0008] The screw rotor, brake rotor, and housing form a compression chamber for compressing the fluid. A nozzle is formed in the portion of the housing facing the compression chamber. The nozzle is located closer to the outer periphery of the compression chamber than the compression chamber itself. A discharge cover is mounted on the axial side of the housing. A discharge outlet is provided on the discharge cover.

[0009] In the screw compressor disclosed in Patent Document 1, since a discharge cover is sandwiched between the nozzle and the discharge outlet, the nozzle and the discharge outlet are necessarily spaced apart from each other in the axial direction. Therefore, after the fluid compressed in the compression chamber flows from the compression chamber toward the nozzle to the outer periphery, its flow direction changes to axial, and it flows axially in the housing to reach the discharge cover, and is ejected out of the discharge cover through the discharge outlet.

[0010] In the screw compressor disclosed in Patent Document 1, the flow direction of the fluid has to be changed from radial to axial in the middle of the flow path from the nozzle to the outlet. This causes pressure loss before the fluid compressed in the compression chamber is ejected to the outside through the nozzle and outlet.

[0011] The purpose of this disclosure is to suppress pressure loss of fluid in a screw compressor.

[0012] - Technical solutions used to solve technical problems -

[0013] The first aspect of this disclosure pertains to a screw compressor 1. The screw compressor 1 includes a screw rotor 20, brake rotors 30 and 35, and a housing 50. The screw rotor 20 has a screw groove 21 and extends along an axial direction X. The brake rotors 30 and 35 have brakes 32 and 37 that mesh with the screw groove 21. The housing 50 holds the screw rotor 20 in a rotatable position and covers the screw rotor 20 from a radial direction R, Ra, orthogonal to the axial direction X. The screw rotor 20, the brake rotors 30 and 35, and the housing 50 form compression chambers S1 and S2 for compressing fluid W. Housing side spray outlets 63 and 64 are formed on the outer wall portion 58 of the housing 50 located on the radial direction R, Ra, from which the fluid W is ejected. Portions 55c and 55d of the housing 50 facing the compression chambers S1 and S2 are formed that connect to the housing side spray outlets 63 and 64. The nozzles 65 and 66 are provided, each including a first end 65a and 66a located on a first direction side Xa in the axial direction X, and a second end 65b and 66b located on a second direction side Xb opposite to the first direction side Xa in the axial direction X. The housing-side nozzles 63 and 64 are located between a first position Ka and a second position Kb in the axial direction X. The first position Ka is a position located from the first end 65a and 66a toward the first direction side Xa at a distance equal to the radius r of the gates 32 and 37. The second position Kb is a position located from the second end 65b and 66b toward the second direction side Xb at a distance equal to the radius r of the gates 32 and 37. The housing-side nozzles 63 and 64 are located in the radial direction R closer to the nozzles 65 and 66 than the screw rotor 20.

[0014] According to the first aspect, the casing-side nozzles 63 and 64 are formed on the outer wall portion 58 of the casing located on the outer side Ra of the radial direction R. The casing-side nozzles 63 and 64 are located between a first position Ka and a second position Kb in the axial direction X. The casing-side nozzles 63 and 64 are not far apart from the nozzles 65 and 66 in the axial direction X. The casing-side nozzles 63 and 64 are easily located near the nozzles 65 and 66 in the axial direction X.

[0015] In the flow path from nozzles 65 and 66 to the shell-side nozzles 63 and 64, the flow direction of fluid W is difficult to change from radial to axial (X). After being compressed in compression chambers S1 and S2, fluid W flows from compression chambers S1 and S2 towards nozzles 65 and 66 to the outer side Ra of radial R. Its flow direction hardly changes to axial (X) and flows almost towards the outer side Ra of radial R, and is ejected out of the shell 50 through the shell-side nozzles 63 and 64.

[0016] The fluid W, compressed in the compression chambers S1 and S2, is ejected outside the casing 50 through nozzles 65 and 66 and casing-side outlets 63 and 64, making pressure loss unlikely. Therefore, in the screw compressor 1, pressure loss of the fluid W can be suppressed.

[0017] The second aspect of this disclosure is that, based on the first aspect, the brake rotors 30 and 35 are housed within brake rotor chambers 59 and 61 disposed in the housing 50, and brake openings 60 and 62 communicating with the brake rotor chambers 59 and 61 are provided on the outer wall of the housing. The housing side spray outlets 63 and 64 and the brake openings 60 and 62 are covered by covers 91 and 93, and cover side spray passages 94 and 97 communicating with the housing side spray outlets 63 and 64 are provided in the covers 91 and 93.

[0018] The gate rotor chambers 59 and 61 housing the gate rotors 30 and 35 are typically arranged near the nozzles 65 and 66 in the axial direction X. The covers 91 and 93 covering the gate openings 60 and 62 are also typically arranged near the nozzles 65 and 66 in the axial direction X. The fact that the housing-side nozzles 63 and 64 are covered by covers 91 and 93 along with the gate openings 60 and 62 means that the housing-side nozzles 63 and 64 are located near the nozzles 65 and 66 in the axial direction X. Furthermore, by providing cover-side ejection paths 94 and 97 communicating with the housing-side nozzles 63 and 64 in the covers 91 and 93, fluid W can flow from the housing 50 side to the cover 91 and 93 side.

[0019] A third aspect of this disclosure is that, based on the second aspect, the housing-side nozzles 63 and 64 are flush with the housing-side mounting surfaces 58a and 58b in the outer wall portion 58 of the housing where the covers 91 and 93 are mounted, and the housing-side mounting surfaces 58a and 58b are sealed to the covers 91 and 93 by a first sealing member 92.

[0020] According to the third aspect, since the housing-side nozzles 63 and 64 are flush with the housing-side mounting surfaces 58a and 58b, the leakage of fluid W ejected from the housing-side nozzles 63 and 64 from the gap between the housing-side mounting surfaces 58a and 58b and the covers 91 and 93 can be suppressed by using the first sealing member 92 to seal the gap between the housing-side mounting surfaces 58a and 58b and the covers 91 and 93.

[0021] A fourth aspect of this disclosure is that, based on the second aspect, the cover-side spray outlets 94, 97 include cover-side insertion tubes 94c, 97c inserted into the housing-side spray outlets 63, 64, and the housing-side spray outlets 63, 64 and the cover-side insertion tubes 94c, 97c are sealed by a second sealing member 101.

[0022] According to the fourth aspect, it is possible to suppress the leakage of fluid W ejected from the shell-side outlets 63 and 64 to the outside before it reaches the cover-side outlets 94 and 97.

[0023] The fifth aspect of this disclosure is that, based on any one of the first to fourth aspects, the housing-side nozzles 63 and 64 are located in the axial direction X at a position overlapping with the nozzles 65 and 66.

[0024] According to the fifth aspect, the casing-side nozzles 63 and 64 can be positioned closer to the nozzles 65 and 66 in the axial direction X. This helps to prevent the fluid W flowing from the compression chambers S1 and S2 toward the outer radial direction Ra of the nozzles 65 and 66 from changing its flow direction to the axial direction X before reaching the casing-side nozzles 63 and 64.

[0025] A sixth aspect of this disclosure is that, based on any one of the first to fifth aspects, a connecting path 67, 68 is provided in the housing 50 to connect the housing-side nozzles 63, 64 with the nozzles 65, 66, the connecting path 67, 68 extending straight.

[0026] According to the sixth aspect, since the connecting paths 67 and 68 extend in a straight line, it is beneficial to suppress the pressure loss of the fluid W flowing in the connecting paths 67 and 68.

[0027] The seventh aspect of this disclosure is that, based on any one of the first to sixth aspects, an ejection pipe 95, 98 is connected to the ejection outlets 63, 64 on the housing side, and a silencer 96 is provided on the ejection pipes 95, 98.

[0028] According to the seventh aspect, by providing a silencing element 96 on the nozzles 95 and 98, it is beneficial to suppress the noise caused by the fluid W flowing in the nozzles 95 and 98.

[0029] The eighth aspect of this disclosure is that, based on any one of the first to seventh aspects, the screw compressor 1 includes a bearing support 73 and a retaining member 77, the bearing support 73 retaining a bearing 74 supporting the screw rotor 20, the retaining member 77 pressing the bearing support 73 along the axial direction X, the retaining member 77 being plate-shaped with the axial direction X as the thickness direction t.

[0030] According to the eighth aspect, since the retaining member 77 is a plate-shaped member with the thickness direction t in the axial direction X, it is advantageous to reduce the size of the screw compressor 1 in the axial direction X.

[0031] The ninth aspect of this disclosure is that, based on any one of the first to eighth aspects, the screw compressor 1 includes slide valves 87 and 89, which adjust the opening C of the nozzles S1 and S2 by moving along the axial direction X.

[0032] According to the ninth aspect, by adjusting the opening C of the nozzles 65 and 66 using slide valves 87 and 89, the apparent volume of the compression chambers S1 and S2 can be easily adjusted.

[0033] The tenth aspect of this disclosure is that, based on any one of the first to ninth aspects, the screw compressor 1 includes a first brake rotor 30 and a second brake rotor 35 as the brake rotors 30 and 35, the screw rotor 20, the first brake rotor 30, and the housing 50 form a first compression chamber S1 as the compression chambers S1 and S2, and the screw rotor 20, the second brake rotor 35, and the housing 50 form a second compression chamber S2 as the compression chambers S1 and S2, and a first housing side spray outlet 63 and 64 as the housing side spray outlet 64 is formed on the outer wall portion 58 of the housing. 3. A first nozzle 65, which serves as the nozzles 65 and 66, is formed in the portion 55c of the housing 50 facing the first compression chamber S1. A second nozzle 66, which serves as the nozzles 65 and 66, is formed in the portion 55d of the housing 50 facing the second compression chamber S2. The first nozzle 65 communicates with the first housing side nozzle 63, and the second nozzle 66 communicates with the second housing side nozzle 64. The first housing side nozzle 63 and the second housing side nozzle 64 are located at different positions in the circumferential direction θ of the screw rotor 20.

[0034] According to the tenth aspect, since the first housing side spray outlet 63 and the second housing side spray outlet 64 are located at different positions in the circumferential direction θ, it is possible to position the first housing side spray outlet 63 and the second housing side spray outlet 64 between a first position Ka and a second position Kb in the axial direction X without interfering with each other.

[0035] The eleventh aspect of this disclosure is, based on any one of the first to tenth aspects, that the screw compressor includes a first brake rotor 30 and a second brake rotor 35 as the brake rotors 30 and 35, the screw rotor 20, the first brake rotor 30, and the housing 50 forming a first compression chamber S1 as the compression chambers S1 and S2, and the screw rotor 20, the second brake rotor 35, and the housing 50 forming a second compression chamber S2 as the compression chambers S1 and S2, a first housing side spray outlet 63 and a second housing side spray outlet 64 as the housing side spray outlets 63 and 64 are formed on the outer wall portion 58 of the housing, a first spray outlet 65 as the nozzles 65 and 66 are formed in the portion 55c of the housing 50 facing the first compression chamber S1, and a second spray outlet 64 as the nozzles 65 and 66 are formed in the portion 55c of the housing 50 facing the second compression chamber S1. A portion 55d of the compression chamber S2 is formed with a second nozzle 66 serving as the nozzles 65 and 66. The first nozzle 65 communicates with the first housing-side nozzle 63, and the second nozzle 66 communicates with the second housing-side nozzle 64. A first ejector pipe 95 is connected to the first housing-side nozzle 63, and a second ejector pipe 98 is connected to the second housing-side nozzle 64. The first ejector pipe 95 and the second ejector pipe 98 merge at the confluence portion 99. The screw compression mechanism is configured such that the pulsation U of the fluid W reaching the confluence portion 99 from the first nozzle 65 via the first housing-side nozzle 63 and the first ejector pipe 95 cancels out the pulsation U of the fluid W reaching the confluence portion 99 from the second nozzle 66 via the second housing-side nozzle 64 and the second ejector pipe 98.

[0036] According to the eleventh aspect, it is beneficial to suppress noise and vibration caused by the pulsation U of fluid W.

[0037] The twelfth aspect of this disclosure is, based on the tenth aspect, that the first compression chamber S1 compresses the fluid W at a first pressure P1 to an intermediate pressure Pm higher than the first pressure P1, and the second compression chamber S2 compresses the fluid W at the intermediate pressure Pm to a second pressure P2 higher than the intermediate pressure Pm, wherein the fluid W flows in the order of the first compression chamber S1, the first nozzle 65, the first housing-side nozzle 63, the second compression chamber S2, the second nozzle 66, and the second housing-side nozzle 64.

[0038] According to the twelfth aspect, the fluid W can be compressed in at least two stages using the first compression chamber S1 and the second compression chamber S2. Attached Figure Description

[0039] Figure 1 The screw compressor according to the first embodiment is shown in the right-hand view.

[0040] Figure 2 The screw compressor 1 is shown in the left-hand view.

[0041] Figure 3 The previous view shows screw compressor 1.

[0042] Figure 4 Along Figure 3 The right-side sectional view obtained by cutting along line IV shows the screw compressor 1.

[0043] Figure 5 Along Figure 4 The front sectional view obtained by cutting along the V-line shows the screw compressor 1.

[0044] Figure 6 Along Figure 4 The front sectional view obtained by cutting along line VI shows the screw compressor 1.

[0045] Figure 7 Along Figure 6 The cross-sectional view obtained by cutting along line VII shows the vicinity of the first nozzle 65.

[0046] Figure 8 The positional relationship between the first housing side spray outlet 63 and the first nozzle 65 is shown in a cross-sectional view with the first slide valve 87 removed.

[0047] Figure 9 Along Figure 6 The view along the IX line shows the positional relationship between the first housing side nozzle 63 and the first gate opening 60.

[0048] Figure 10 Along Figure 4 The front sectional view obtained by X-ray cutting shows the screw compressor 1.

[0049] Figure 11 Along Figure 4 The front sectional view obtained by cutting along line XI shows the screw compressor 1.

[0050] Figure 12 The positional relationship between the rotating body A and the connecting path F is shown in the cross-sectional view on the right.

[0051] Figure 13 The second embodiment is equivalent to Figure 3 The diagram, with the previous view showing screw compressor 1.

[0052] Figure 14 The cover-side spray paths 94 and 97 of the third embodiment are shown. Detailed Implementation

[0053] <First Implementation>

[0054] (Screw compressor)

[0055] The screw compressor 1 according to the first embodiment will now be described. The screw compressor 1 is suitable for refrigeration devices such as air conditioners. The refrigeration device includes a refrigerant circuit for refrigerant circulation. The screw compressor 1 compresses the refrigerant in the refrigerant circuit. In the refrigerant circuit, the refrigerant circulates, thereby performing a vapor compression refrigeration cycle.

[0056] Figures 1-5 The screw compressor 1 according to the first embodiment is shown. In the following description, it will sometimes be referred to as... Figure 1 The left side is called the front side. Figure 1 The right side is called the rear side. Figure 1 The upper side is called the upper side, which will Figure 1 The lower side is called the lower side. Figure 1 The side of the paper with the greatest depth is called the left side. Figure 1 The front side of the paper is called the right side. Figure 1 This is the right-side view. Figure 2 This is the left-side view. Figure 3 This is the front view. Figure 4 It is along Figure 3 The right-side sectional view obtained by cutting along line IV. Figure 5 It is along Figure 4 The front sectional view is obtained by cutting along the V-line. The front-back and left-right directions constitute the horizontal direction. The up-down direction constitutes the vertical direction V.

[0057] The screw compressor 1 includes a shaft 10, a screw rotor 20, a first brake rotor 30, a second brake rotor 35, a motor 40, and a housing 50.

[0058] The screw compressor 1 includes a front cover 70, a front bearing 71, a front bearing bracket 72, a rear bearing bracket 73, a rear bearing 74, a spacer 75, an elastic retaining ring 76, a retaining member 77, an intermediate bearing 78, a base-side first gate bearing 79, a top-side first gate bearing 80, a base-side first gate bearing bracket 81, a top-side first gate bearing bracket 82, a base-side second gate bearing 83, a top-side second gate bearing 84, a base-side second gate bearing bracket 85, and a top-side second gate bearing bracket 86.

[0059] The screw compressor 1 includes a first slide valve 87, a first valve moving mechanism 88, a second slide valve 89, a second valve moving mechanism 90, a first cover 91, a gasket 92 serving as a first sealing component, a second cover 93, a first cover-side ejection path 94, a first ejection pipe 95, a silencer 96, a second cover-side ejection path 97, and a second ejection pipe 98.

[0060] (axis)

[0061] like Figure 4 As shown, the central axis O of shaft 10 extends in the front-to-back direction in the horizontal direction. The direction in which the central axis O of shaft 10 extends is called the axial direction X. Axial direction X is the front-to-back direction. The screw compressor 1 is horizontally mounted. The front side of axial direction X is called the front side Xa, which is the first direction side of axial direction X. The rear side of axial direction X is called the rear side Xb, which is the second direction side of axial direction X. The rear side Xb of axial direction X is located on the opposite side to the front side Xa of axial direction X.

[0062] The radial direction R of the screw compressor 1 is orthogonal to the axial direction X. The side of the radial direction R furthest from the central axis O is called the outer circumference (outer side) Ra of the radial direction R. The side of the radial direction R closest to the central axis O is called the inner circumference (inner side) Rb of the radial direction R. The vertical direction, which is part of the radial direction R, is consistent with the vertical direction V. The side above the vertical direction V is called the upper side (above) Va. The side below the vertical direction V is called the lower side (below) Vb. The circumferential direction θ of the screw compressor 1 is the direction around the central axis O.

[0063] (Screw rotor)

[0064] The screw rotor 20 is coupled to the shaft 10, and the screw rotor 20 and the shaft 10 rotate integrally. The screw rotor 20 extends along the axial direction X, just like the shaft 10. The screw rotor 20 has multiple screw grooves 21, a front rotary seal 22, and a rear rotary seal 23. The screw rotor 20 is made of, for example, metal.

[0065] Multiple screw grooves 21 are disposed in the middle part of the outer periphery of the screw rotor 20 along the axial direction X. The multiple screw grooves 21 are arranged in the axial direction X. The screw grooves 21 are helical.

[0066] The front rotary seal 22 is located at the front end of the outer periphery of the screw rotor 20 along the central axis X. The rear rotary seal 23 is located at the rear end of the outer periphery of the screw rotor 20 along the central axis X. No screw groove 21 is provided on either the front rotary seal 22 or the rear rotary seal 23.

[0067] (First brake rotor)

[0068] like Figure 5 As shown, the first brake rotor 30 is positioned closer to the outer periphery R than the screw rotor 20. The first brake rotor 30 is positioned closer to the left side than the screw rotor 20.

[0069] The first brake rotor 30 has a first brake shaft 31 and a first brake 32. The first brake rotor 30 is made of, for example, resin. The first brake shaft 31 extends in the vertical direction V. The first brake 32 is fixed to the middle part of the first brake shaft 31. The first brake 32 is in a generally disc-shaped form concentric with the first brake shaft 31. A plurality of first brake teeth are provided on the outer periphery of the first brake 32. The first brake teeth of the first brake 32 of the first brake rotor 30 mesh with the screw groove 21 of the screw rotor 20.

[0070] The first gate 32 has a gate radius r. The gate radius r is the radius of the first gate 32. The gate radius r is half the diameter of the first gate 32. The gate radius r is the distance from the center of the first gate 32 to its outer perimeter.

[0071] (Second brake rotor)

[0072] like Figure 5 As shown, the second brake rotor 35 is positioned closer to the outer periphery Ra than the screw rotor 20. The second brake rotor 35 is positioned closer to the right side and lower than the screw rotor 20 at a position Vb.

[0073] The second brake rotor 35 has a second brake shaft 36 and a second brake 37. The second brake rotor 35 is made of, for example, resin. The second brake shaft 36 extends obliquely relative to the vertical direction V. The second brake shaft 36 extends such that it is closer to the right side the closer it is to the upper side Va. The second brake 37 is fixed to the middle part of the second brake shaft 36. The second brake 37 is approximately disc-shaped and concentric with the second brake shaft 36. A plurality of second brake teeth are provided on the outer periphery of the second brake 37. The second brake teeth of the second brake 37 of the second brake rotor 35 mesh with the screw groove 21 of the screw rotor 20.

[0074] The second gate 37 has a gate radius r. The gate radius r is the radius of the second gate 37. The gate radius r is half the diameter of the second gate 37. The gate radius r is the distance from the center of the second gate 37 to its outer perimeter.

[0075] (Electric motor)

[0076] like Figure 4 As shown, the electric motor 40 includes a motor rotor 41 and a motor stator 42. The motor rotor 41 is coupled to the shaft 10, and the motor rotor 41 rotates integrally with the shaft 10. The motor rotor 41 is arranged at a position closer to the front side Xa of the axial direction X than the screw rotor 20. The motor stator 42 is fixed to the inner wall of the housing 50 (described later) via a fastener (not shown). The motor rotor 41 and the motor stator 42 are opposite each other at a predetermined interval in the radial direction R.

[0077] (case)

[0078] like Figures 1-4 As shown, the shell 50 is generally cylindrical. Figure 4As shown, a front opening 50a is provided at the front end of the housing 50. A rear opening 50b is provided at the rear end of the housing 50. The housing 50 is divided in the axial direction X by a partition wall 53 into a motor housing 51 located at the front Xa side of the axial direction X and a compression chamber forming part 52 located at the rear Xb side of the axial direction X.

[0079] like Figure 4 As shown, a motor chamber 54 is provided in the motor housing 51 of the housing 50. The motor chamber 54 is formed by a cavity within the housing 50. The shaft 10 and the motor 40 are housed in the motor chamber 54. The motor rotor 41 and the motor stator 42 of the motor 40 are housed in the motor chamber 54. The front ends of the shaft 10 and the motor 40 protrude forward Xa beyond the motor chamber 54 via the front opening 50a.

[0080] The front cover 70 covers the front opening 50a of the housing 50. An inner protrusion 70a protruding towards the inner circumferential side Rb is provided on the inner wall of the front cover 70. A front bearing 71 is held on the inner protrusion 70a of the front cover 70. The front bearing 71 rotatably supports the front end of the shaft 10 on the front cover 70. A front bearing bracket 72 holds the front bearing 71 to the front cover 70.

[0081] like Figure 4 As shown, a cylindrical wall portion 55 is provided in the compression chamber forming portion 52 of the housing 50. A screw rotor 20 is arranged in the front part of the cylindrical wall portion 55 in the axial direction X. A rear bearing bracket 73, which will be described later, is arranged in the rear part of the cylindrical wall portion 55 in the axial direction X.

[0082] like Figure 5 As shown, the inner circumferential surface of the cylindrical wall portion 55 of the housing 50 covers the screw groove 21 of the screw rotor 20 from the outer circumferential side Ra in the radial direction R. The inner diameter of the cylindrical wall portion 55 is slightly larger than the outer diameter of the screw rotor 20. A first slit 56 penetrating the first gate 32 is provided on the cylindrical wall portion 55. A second slit 57 penetrating the second gate 37 is provided on the cylindrical wall portion 55.

[0083] like Figure 4 As shown, a front fixed seal portion (hereinafter referred to as "front fixed seal portion 55a") is provided on the portion 55a of the inner circumferential surface of the cylindrical wall portion 55 of the housing 50 facing the front rotary seal portion 22 of the screw rotor 20. A rear fixed seal portion (hereinafter referred to as "rear fixed seal portion 55b") is provided on the portion 55b of the inner circumferential surface of the cylindrical wall portion 55 of the housing 50 facing the rear rotary seal portion 23 of the screw rotor 20.

[0084] As mentioned above, such as Figure 4As shown, the rear bearing support 73 is arranged on the rear portion of the cylindrical wall portion 55 in the axial direction X. The rear bearing support 73 is held on the inner circumferential surface of the cylindrical wall portion 55. The rear bearing support 73 is generally cylindrical. The rear bearing support 73 includes a first portion 73a extending in the axial direction X and a second portion 73b extending from the front end of the first portion 73a toward the inner circumferential side Rb in the radial direction R.

[0085] There are two rear bearings 74. The two rear bearings 74 are arranged axially in the X direction. The rear bearings 74 are arranged radially in the R direction between the first portion 73a of the rear bearing bracket 73 and the rear end of the shaft 10. The rear bearing bracket 73 holds the rear bearings 74. Specifically, the inner circumferential surface of the first portion 73a of the rear bearing bracket 73 holds the outer circumferential surface of the rear bearings 74.

[0086] The rear bearing 74 rotatably supports the rear end of the shaft 10 on the cylindrical wall 55 of the housing 50. The rear bearing 74 supports the screw rotor 20 rotatably via the shaft 10.

[0087] Spacer 75 is clamped between the second part 73b of the rear bearing bracket 73 and the front rear bearing 74. Resilient retaining ring 76 is arranged at the rear end of the rear bearing 74. Resilient retaining ring 76 positions the rear bearing 74 in the axial direction X.

[0088] The retaining member 77 covers the rear opening 50b of the housing 50. The retaining member 77 is plate-shaped. The retaining member 77 has its thickness direction t in the axial direction X. The retaining member 77 is generally disk-shaped. The length of the retaining member 77 in the axial direction X is shorter than its length in the radial direction R.

[0089] The front surface of the retaining member 77 contacts the rear end of the first portion 73a of the rear bearing bracket 73. The retaining member 77 presses the rear bearing bracket 73 forward Xa in the axial direction X. The retaining member 77 holds the rear bearing bracket 73 on the cylindrical wall portion 55 of the housing 50.

[0090] As mentioned above, such as Figure 4 As shown, the partition wall 53 divides the housing 50 into a motor housing 51 and a compression chamber forming portion 52 along the axial direction X. The partition wall 53 extends radially R. The partition wall 53 is positioned closer to the front side Xa of the axial direction X than the cylindrical wall 55. The front surface of the partition wall 53 faces the motor chamber 54. The rear surface of the partition wall 53 faces the front end of the screw rotor 20.

[0091] A shaft through hole 53a is formed in the partition wall portion 53. The shaft through hole 53a penetrates the partition wall portion 53 along the axial direction X. The shaft 10 penetrates the shaft through hole 53a along the axial direction X.

[0092] An intermediate bearing 78 is arranged in the shaft through hole 53a at the partition wall portion 53. The intermediate bearing 78 supports the shaft 10 in a rotatable manner on the partition wall portion 53 of the housing 50.

[0093] The front bearing 71, the rear bearing 74, and the intermediate bearing 78 support the shaft 10 rotatably within the housing 50. The housing 50 holds the shaft 10 rotatably. The housing 50 holds the screw rotor 20 rotatably. The housing 50 holds the motor rotor 41 rotatably.

[0094] (Outer wall of the shell)

[0095] like Figures 3-5 As shown, an outer wall portion 58 is present on the outer peripheral side Ra of the radial direction R in the housing 50. The outer wall portion 58 is a wall portion arranged on the outer peripheral side Ra of the radial direction R in the housing 50.

[0096] (Gate rotor chamber)

[0097] like Figure 5 As shown, a first brake rotor chamber 59 is provided in the housing 50. The first brake rotor chamber 59 is formed in the housing 50 at a position closer to the radial outer periphery Ra than the cylindrical wall portion 55. The first brake rotor chamber 59 is formed in the housing 50 at a position closer to the left side than the cylindrical wall portion 55. The first brake rotor chamber 59 and the first compression chamber S1 are connected to each other via a first slit 56.

[0098] The first brake rotor 30 is housed within the first brake rotor chamber 59. The first brake rotor chamber 59 also houses the base-side first brake bearing 79, the top-side first brake bearing 80, the base-side first brake bearing bracket 81, and the top-side first brake bearing bracket 82.

[0099] There is one base-end side first brake bearing 79. The base-end side first brake bearing 79 supports the base end (upper end) of the first brake shaft 31 of the first brake rotor 30 so that it can rotate. There are two top-end side first brake bearings 80. The top-end side first brake bearings 80 support the top end (lower end) of the first brake shaft 31 of the first brake rotor 30 so that it can rotate.

[0100] The base-side first brake bearing bracket 81 is positioned closer to the upper Va than the first brake rotor 30. The base-side first brake bearing bracket 81 holds the base-side first brake bearing 79 to the housing 50. The base-side first brake bearing bracket 81 can be mounted on the first brake rotor chamber 59 of the housing 50 from the upper Va and removed from the first brake rotor chamber 59 of the housing 50.

[0101] The top-side first brake bearing bracket 82 is positioned closer to the lower side Vb than the first brake rotor 30. The top-side first brake bearing bracket 82 holds the top-side first brake bearing 80. The top-side first brake bearing bracket 82 can be installed into and removed from the first brake rotor chamber 59 of the housing 50 from the lower side Vb.

[0102] A first gate opening 60 is formed on the outer wall portion 58 of the housing 50 on the left side. The first gate opening 60 communicates with the first gate rotor chamber 59.

[0103] like Figure 5 As shown, a second brake rotor chamber 61 is provided in the housing 50. The second brake rotor chamber 61 is formed in the housing 50 at a position closer to the radial outer periphery Ra than the cylindrical wall portion 55. The second brake rotor chamber 61 is formed in the housing 50 at a position closer to the right side and lower side Vb than the cylindrical wall portion 55. The second brake rotor chamber 61 and the second compression chamber S2 are connected to each other via the second slit 57.

[0104] The second brake rotor 35 is housed within the second brake rotor chamber 61. The second brake rotor chamber 61 also houses the base-side second brake bearing 83, the top-side second brake bearing 84, the base-side second brake bearing bracket 85, and the top-side second brake bearing bracket 86.

[0105] There is one base-end side second brake bearing 83. The base-end side second brake bearing 83 supports the base end (lower and left side end) of the second brake shaft 36 of the second brake rotor 35 so that it can rotate. There are three top-end side second brake bearings 84. The top-end side second brake bearings 84 support the top end (upper and right side end) of the second brake shaft 36 of the second brake rotor 35 so that it can rotate.

[0106] The base-side second gull bearing bracket 85 is positioned closer to the lower Vb and to the left than the second gull rotor 35. The base-side second gull bearing bracket 85 holds the base-side second gull bearing 83. The base-side second gull bearing bracket 85 can be installed into and removed from the second gull rotor chamber 61 of the housing 50 from the lower Vb and to the left.

[0107] The top-side second brake bearing bracket 86 is positioned closer to the upper Va and to the right than the second brake rotor 35. The top-side second brake bearing bracket 86 holds the top-side second brake bearing 84. The top-side second brake bearing bracket 86 can be installed into and removed from the second brake rotor chamber 61 of the housing 50 from the upper Va and right side.

[0108] A second gate opening 62 is provided on the outer wall portion 58 of the housing 50, located on the lower Vb and the right side. The second gate opening 62 communicates with the second gate rotor chamber 61.

[0109] (Compression chamber)

[0110] like Figure 5 As shown, the screw groove 21 of the screw rotor 20, the first gate 32 of the first gate rotor 30, and the cylindrical wall portion 55 of the housing 50 form a first compression chamber S1. The first compression chamber S1 compresses the working fluid W. The screw groove 21 of the screw rotor 20, the second gate 37 of the second gate rotor 35, and the cylindrical wall portion 55 of the housing 50 form a second compression chamber S2. The second compression chamber S2 compresses the working fluid W. The working fluid W is, for example, a refrigerant gas.

[0111] The first compression chamber S1 is located on the upper side Va of the vertical direction V, which is closer to the central axis O of the screw rotor 20 (shaft 10). Specifically, when the first compression chamber S1 is represented by a first range S1a in the circumferential direction θ around the central axis O, more than half of the first compression chamber S1 (first range S1a) is located on the upper side Va of the vertical direction V, which is closer to the central axis O (refer to...). Figure 6 ).

[0112] The second compression chamber S2 is located at a position Vb closer to the lower side of the vertical direction V than the central axis O of the screw rotor 20 (shaft 10). Specifically, when the second compression chamber S2 is represented by a second range S2a in the circumferential direction θ around the central axis O, more than half of the second compression chamber S2 (second range S2a) is located at a position Vb closer to the lower side of the vertical direction V than the central axis O (refer to...). Figure 6 ).

[0113] (Side spray outlet on the casing)

[0114] Figure 6 Along Figure 4 The front sectional view obtained by cutting along line VI shows the screw compressor 1. A first housing-side nozzle 63 is provided on the outer wall portion 58 of the housing 50 on the left side. Working fluid W is ejected from the first housing-side nozzle 63 to the outside of the housing 50. A second housing-side nozzle 64 is provided on the outer wall portion 58 of the housing 50 on the lower Vb and right side. Working fluid W is ejected from the second housing-side nozzle 64 to the outside of the housing 50.

[0115] (spout)

[0116] like Figure 6As shown, a first nozzle 65 is formed in the portion 55c of the cylindrical wall 55 of the housing 50 facing the first compression chamber S1. The first nozzle 65 is positioned on the upper side Va and to the left of the screw rotor 20. The first nozzle 65 is formed on the inner circumferential surface of the cylindrical wall 55. When viewed along the axial direction X, the first nozzle 65 is formed in a generally semi-circular shape. The first nozzle 65 communicates with the first compression chamber S1.

[0117] A second nozzle 66 is formed in the portion 55d of the cylindrical wall 55 of the housing 50 facing the second compression chamber S2. The second nozzle 66 is arranged on the lower side Vb and the right side relative to the screw rotor 20. The second nozzle 66 is formed on the inner circumferential surface of the cylindrical wall 55. When viewed along the axial direction X, the second nozzle 66 is formed in a generally semi-circular shape. The second nozzle 66 communicates with the second compression chamber S2.

[0118] like Figure 6 As shown, the first housing side spray outlet 63 and the second housing side spray outlet 64 are located at different positions on the circumferential θ (direction around the central axis O) of the screw rotor 20.

[0119] (Connecting Road)

[0120] like Figure 6 As shown, a first connecting passage 67 is provided on the housing 50. The first connecting passage 67 is formed by opening a hole in the wall of the housing 50. The first connecting passage 67 traverses the first guillotine chamber 59 in the housing 50 in a left-right direction. The first connecting passage 67 connects the first housing side spray outlet 63 to the first nozzle 65. The first nozzle 65 communicates with the first housing side spray outlet 63 via the first connecting passage 67. The first connecting passage 67 extends in a straight line.

[0121] A second connecting passage 68 is provided on the housing 50. The second connecting passage 67 is formed by openings in the wall of the housing 50. The second connecting passage 68 obliquely traverses the second guillotine chamber 61 in the housing 50 with respect to the vertical and horizontal directions. The second connecting passage 68 connects the second housing side spray outlet 64 to the second nozzle 66. The second nozzle 66 communicates with the second housing side spray outlet 64 via the second connecting passage 68. The second connecting passage 68 extends in a straight line.

[0122] (Slide valve)

[0123] Figure 7 Along Figure 6 The cross-sectional view obtained by cutting along line VII shows the vicinity of the first nozzle 65. As described above, the first nozzle 65 is formed in the portion 55c of the cylindrical wall 55 of the housing 50 facing the first compression chamber S1. At the first nozzle 65, the first slide valve 87 moves along the axial direction X.

[0124] If the first slide valve 87 moves along the axial direction X, its position relative to the first compression chamber S1 changes. The first slide valve 87 adjusts the opening C of the first nozzle 65 by moving along the axial direction X. If the first slide valve 87 is in the front position Ja, the space between the first compression chamber S1 and the first nozzle 65 is blocked by the first slide valve 87, thus the opening C of the first nozzle 65 decreases. If the first slide valve 87 is in the rear position Jb (refer to the double-dotted line), the space between the first compression chamber S1 and the first nozzle 65 is opened, thus the opening C of the first nozzle 65 increases.

[0125] The first valve moving mechanism 88 moves the first slide valve 87 along the axial direction X. The first valve moving mechanism 88 is composed of a cylinder-piston mechanism. The first valve moving mechanism 88 has a cylinder 88a, a piston 88b, and a rod 88c. The piston 88b is arranged inside the cylinder 88a. The rod 88c extends from the front surface of the piston 88b toward the front side X of the axial direction X and is connected to the rear end of the first slide valve 87.

[0126] A pressure control chamber 88d is formed within cylinder 88a at a position closer to the rear Xb of the axial direction X than piston 88b. If high pressure is introduced into pressure control chamber 88d, the first slide valve 87 moves together with piston 88b and rod 88c toward the front Xa of the axial direction X. The first valve moving mechanism 88 applies a force to the first slide valve 87 toward the rear Xb of the axial direction X via a spring, which is not shown.

[0127] At the second nozzle 66, the second slide valve 89 (refer to...) Figure 6 The second slide valve 89 moves along the axial direction X, the details of which are omitted. The second slide valve 89 adjusts the opening C of the second nozzle 66 by moving along the axial direction X. The second valve moving mechanism 90 (see...) Figure 1 , Figure 2 This causes the second slide valve 89 to move along the axial direction X. The detailed structure of the second slide valve 89 and the second valve moving mechanism 90 is the same as that of the first slide valve 87 and the first valve moving mechanism 88.

[0128] (Positional relationship between the side nozzle and the nozzle on the casing)

[0129] Figure 8 The positional relationship between the first housing side spray outlet 63 and the first nozzle 65 is shown in a cross-sectional view with the first slide valve 87 removed.

[0130] like Figure 8 As shown, the first nozzle 65 includes a front end portion 65a as a first end portion and a rear end portion 65b as a second end portion. The front end portion 65a is the end portion of the first nozzle 65 on the front side Xa in the axial direction X. The rear end portion 65b is the end portion of the first nozzle 65 on the rear side Xb in the axial direction X.

[0131] The first position, Ka, is defined as the position at which the front end 65a of the first nozzle 65 moves away from the front side Xa in the axial direction X, at a distance equal to the gate radius r of the first gate 32. The second position, Kb, is defined as the position at which the rear end 65b of the first nozzle 65 moves away from the rear side Xb in the axial direction X, at a distance equal to the gate radius r of the first gate 32.

[0132] The first housing side spray outlet 63 is located between the front position Ka and the rear position Kb in the axial X direction. The first housing side spray outlet 63 is located at a position overlapping with the first nozzle 65 in the axial X direction.

[0133] At least a portion of the opening width B of the first housing side spray outlet 63 in the axial X direction is located between the front position Ka and the rear position Kb in the axial X direction.

[0134] like Figure 6 As shown, the first housing-side nozzle 63 is located radially closer to the first nozzle 65 than the screw rotor 20. The radial distance between the first housing-side nozzle 63 and the first nozzle 65 is shorter than the radial distance between the first housing-side nozzle 63 and the screw rotor 20.

[0135] The positional relationship between the second housing side nozzle 64 and the second nozzle 66 is almost identical to the positional relationship between the first housing side nozzle 63 and the first nozzle 65. While strictly speaking, this differs slightly from the actual situation, for the sake of simplicity, it is used in this context... Figure 8 The symbols enclosed in parentheses illustrate the positional relationship between the second housing-side nozzle 64 and the second nozzle 66. It should be noted that in the description of the positional relationship between the second housing-side nozzle 64 and the second nozzle 66, details that are the same as those for the positional relationship between the first housing-side nozzle 63 and the first nozzle 65 are sometimes omitted.

[0136] like Figure 8 As shown, the second nozzle 66 includes a front end portion 66a as a first end portion and a rear end portion 66b as a second end portion. The front end portion 66a is the end portion of the second nozzle 66 at the front side Xa of the axial direction X. The rear end portion 66b is the end portion of the second nozzle 66 at the rear side Xb of the axial direction X.

[0137] The first position, Ka, is defined as the position located at a distance equal to the gate radius r of the second gate 37, moving from the front end 66a of the second nozzle 66 towards the front side Xa in the axial direction X. The second position, Kb, is defined as the position located at a distance equal to the gate radius r of the second gate 37, moving from the rear end 66b of the second nozzle 66 towards the rear side Xb in the axial direction X.

[0138] The second housing side nozzle 64 is located between the front position Ka and the rear position Kb in the axial X direction. The second housing side nozzle 64 is located at a position overlapping with the second nozzle 66 in the axial X direction.

[0139] like Figure 6 As shown, the second housing side nozzle 64 is located on the side closer to the second nozzle 66 in the radial direction R than the screw rotor 20.

[0140] (Positional relationship between the spray outlet on the casing side and the gate opening)

[0141] Figure 9 Along Figure 6 The cross-sectional view obtained by cutting along line IX shows the positional relationship between the first housing side spray outlet 63 and the first gate opening 60.

[0142] like Figure 6 , Figure 9 As shown, the first brake shaft 31 and the first brake 32 of the first brake rotor 30 can be seen through the first brake opening 60. The first housing side spray outlet 63 is arranged inside the first brake opening 60.

[0143] The first housing side spray outlet 63 and the first gate opening 60 are covered by a common first cover 91. The first cover 91 is also referred to as the side cover. The first cover 91 is generally disc-shaped. A first housing side mounting surface 58a is provided at the periphery of the first gate opening 60 in the housing outer wall portion 58. The first cover 91 is mounted on the first housing side mounting surface 58a. The first housing side spray outlet 63 is flush with the first housing side mounting surface 58a in the housing outer wall portion 58 where the first cover 91 is mounted.

[0144] The first housing side spray outlet 63 being flush with the first housing side mounting surface 58a means that there is almost no height difference between the outer peripheral end of the first housing side spray outlet 63 and the first housing side mounting surface 58a. The height difference between the two is preferably less than 1 mm, more preferably less than 0.5 mm, and even more preferably less than 0.1 mm.

[0145] like Figure 6 As shown, a gasket 92 is arranged between the mounting surface 58a on the first housing side and the first cover 91. The gasket 92 is a sheet gasket or a spiral washer. It should be noted that an O-ring can also be used as the gasket 92. The mounting surface 58a on the first housing side and the first cover 91 are sealed by the gasket 92.

[0146] The positional relationship between the second housing side spray outlet 64 and the second gate opening 62 is almost identical to the positional relationship between the first housing side spray outlet 63 and the first gate opening 60. Although strictly speaking, it differs slightly from the actual situation, but for the sake of simplification, in... Figure 9The symbols enclosed in parentheses illustrate the positional relationship between the second housing-side spray outlet 64 and the second gate opening 62. It should be noted that in the description of the positional relationship between the second housing-side spray outlet 64 and the second gate opening 62, details concerning the same positional relationship as that between the first housing-side spray outlet 63 and the first gate opening 60 are sometimes omitted.

[0147] The second housing-side nozzle 64 and the second gate opening 62 are covered by a shared second cover 93. The second housing-side nozzle 64 is flush with the second housing-side mounting surface 58b in the outer wall portion 58 of the housing, where the second cover 93 is mounted. The second housing-side mounting surface 58b and the second cover 93 are sealed by a gasket 92.

[0148] (build)

[0149] like Figure 6 As shown, a first cover-side ejection passage 94 is provided in the first cover 91. The first cover-side ejection passage 94 includes a hole 94a and a tube 94b. The hole 94a of the first cover-side ejection passage 94 penetrates the first cover 91 radially R. The hole 94a of the first cover-side ejection passage 94 is connected to the first housing-side ejection outlet 63. The first cover-side ejection passage 94 communicates with the first housing-side ejection outlet 63. The tube 94b of the first cover-side ejection passage 94 is located closer to the outer peripheral side Ra of the first cover 91 in the radial direction R, and extends radially R. The first cover 91 and the first cover-side ejection passage 94 are formed integrally.

[0150] One end of a first ejection pipe 95 is connected to the end of the first cover-side ejection passage 94. In other words, the first ejection pipe 95 is connected to the first housing-side ejection outlet 63 via the first cover-side ejection passage 94. The first ejection pipe 95 communicates with the first cover-side ejection passage 94. In other words, the first ejection pipe 95 communicates with the first housing-side ejection outlet 63 via the first cover-side ejection passage 94. The other end of the first ejection pipe 95 is connected to the second suction port 69c, which will be described later.

[0151] A silencing element 96 is provided on the first ejection pipe 95. Specifically, the silencing element 96 is wound around the outer periphery of the first ejection pipe 95. The silencing element 96 is made of, for example, sponge, polyurethane, etc.

[0152] like Figure 6 As shown, a second cover-side ejection passage 97 is provided in the second cover 93. The second cover-side ejection passage 97 includes a hole 97a and a tube 97b. The hole 97a of the second cover-side ejection passage 97 penetrates the second cover 93 radially R. The hole 97a of the second cover-side ejection passage 97 is connected to the second housing-side ejection outlet 64. The second cover-side ejection passage 97 communicates with the second housing-side ejection outlet 64. The tube 97b of the second cover-side ejection passage 97 is located closer to the outer peripheral side Ra of the second cover 93 in the radial direction R, and extends radially R. The second cover 93 and the second cover-side ejection passage 97 are formed integrally.

[0153] One end of a second ejector pipe 98 is connected to the end of the second cover-side ejector passage 97. In other words, the second ejector pipe 98 is connected to the second housing-side ejector outlet 64 via the second cover-side ejector passage 97. The second ejector pipe 98 communicates with the second cover-side ejector passage 97. In other words, the second ejector pipe 98 communicates with the second housing-side ejector outlet 64 via the second cover-side ejector passage 97. The other end of the second ejector pipe 98 is connected, for example, to the condenser in the refrigerant circuit. A muffler 96 is provided on the second ejector pipe 98. Specifically, a muffler 96 is wound around the outer periphery of the second ejector pipe 98.

[0154] (suction port)

[0155] like Figure 4 As shown, a first suction port 69a is formed on the upper side of the outer wall portion 58 of the compression chamber forming portion 52 of the housing 50. The first suction port 69a communicates with the first compression chamber S1 via a first suction passage 69b provided on the cylindrical wall portion 55.

[0156] like Figure 4 As shown, a second intake port 69c is formed on the outer wall portion 58 of the motor housing portion 51 of the housing 50. The second intake port 69c communicates with the motor chamber 54 via a second intake passage 69d.

[0157] (Two-stage compression)

[0158] Screw compressor 1 is a two-stage screw compressor. The first compression chamber S1 compresses the working fluid W at a first pressure P1 to an intermediate pressure Pm, which is higher than the first pressure P1. The second compression chamber S2 compresses the working fluid W at the intermediate pressure Pm to a second pressure P2, which is higher than the intermediate pressure Pm. The first compression chamber S1 is also called the low-pressure compression chamber. The second compression chamber S2 is also called the high-pressure compression chamber. The first pressure P1 is also called low pressure. The second pressure P2 is also called high pressure.

[0159] The working fluid W flows in the following order: first suction inlet 69a, first suction path 69b, first compression chamber S1, first nozzle 65, first connecting path 67, first housing side nozzle 63, first cover side nozzle 94, first nozzle pipe 95, second suction inlet 69c, second suction path 69d, motor chamber 54 (serving as intermediate chamber Sm), second compression chamber S2, second nozzle 66, second connecting path 68, second housing side nozzle 64, second cover side nozzle 97, and second nozzle pipe 98.

[0160] (Sealing part)

[0161] Figure 10 Along Figure 4 The front sectional view obtained by X-ray cutting shows the screw compressor 1. (See image below.) Figure 4, Figure 10 As shown, the front fixed sealing portion 55a on the inner circumferential surface of the cylindrical wall portion 55 of the housing 50 and the front rotating sealing portion 22 of the screw rotor 20 slide against each other with a small gap in the radial direction R. Figure 10 As shown, the front fixed sealing part 55a is arranged in the vertical direction V at a position closer to the upper side Va than the central axis O. The front fixed sealing part 55a and the front rotating sealing part 22 slide against each other in the vertical direction V at a position closer to the upper side Va than the central axis O.

[0162] like Figure 4 As shown, the front fixed sealing part 55a and the front rotating sealing part 22 seal the motor chamber 54 (intermediate chamber Sm) and the first compression chamber S1. The motor chamber 54 is sealed by the front fixed sealing part 55a and the front rotating sealing part 22, thereby not communicating with the first compression chamber S1.

[0163] As described above, the working fluid W must flow from the motor chamber 54 to the second compression chamber S2, rather than from the motor chamber 54 to the first compression chamber S1. The front fixed seal 55a and the front rotating seal 22 prevent the working fluid W from flowing from the motor chamber 54 to the first compression chamber S1.

[0164] (Connecting path)

[0165] Figure 11 Along Figure 4 The front sectional view obtained by cutting along line XI shows the screw compressor 1. (See image below.) Figure 4 , Figure 11 As shown, a connecting hole 53b is formed on the partition wall portion 53 of the housing 50. The connecting hole 53b penetrates the partition wall portion 53 along the axial direction X.

[0166] The connecting hole 53b constitutes the connecting path F. In other words, the connecting path F includes the connecting hole 53b. The connecting path F is arranged in the vertical direction V at a position closer to the lower side Vb than the central axis O.

[0167] Connecting path F connects motor chamber 54 to second compression chamber S2. Motor chamber 54 is connected to second compression chamber S2 via connecting path F.

[0168] The connecting path F includes an inclined section Fa. The inclined section Fa slopes upward from the motor chamber 54 side of the front side Xa of the axial direction X toward the second compression chamber S2 side of the rear side Xb of the axial direction X.

[0169] (Positional relationship between the solid of revolution and the connecting path)

[0170] Figure 12The positional relationship between rotating body A and connecting path F is shown in a cross-sectional view. Rotating body A includes shaft 10, screw rotor 20, and motor rotor 41. The outermost diameter DA of rotating body A is the larger of the outermost diameter D20 of screw rotor 20 and the outermost diameter D41 of motor rotor 41. In this example, since the outermost diameter D41 of motor rotor 41 is larger than the outermost diameter D20 of screw rotor 20, the outermost diameter DA of rotating body A is the outermost diameter D41 of motor rotor 41.

[0171] The lower end Fb of the connecting path F is located closer to the lower side Vb of the vertical direction V than the outermost diameter DA of the rotating body A.

[0172] (Oil storage chamber)

[0173] like Figure 12 As shown, an oil reservoir G is formed on the inner bottom surface 50c of the lower side Vb of the housing 50 in the vertical direction V. Oil g is stored in the oil reservoir G. The oil g is contained as mist in the working fluid W, and after being separated by an oil separator (arranged outside the screw compressor 1, not shown), it accumulates in the oil reservoir G. When the flow rate of the working fluid W is sufficiently ensured, the oil level G0 of the oil g in the oil reservoir G is approximately at the same height as the lower end Fb of the connecting passage F in the vertical direction V.

[0174] (Function and effect)

[0175] According to this embodiment, the housing-side nozzles 63 and 64 are formed on the outer peripheral wall portion 58 of the housing located on the radial side Ra. The housing-side nozzles 63 and 64 are located between a first position Ka and a second position Kb in the axial direction X. The housing-side nozzles 63 and 64 are not far apart from the nozzles 65 and 66 in the axial direction X. The housing-side nozzles 63 and 64 are easily located near the nozzles 65 and 66 in the axial direction X.

[0176] In the flow path from nozzles 65 and 66 to the shell-side nozzles 63 and 64, the flow direction of fluid W is difficult to change from radial to axial (X). After being compressed in compression chambers S1 and S2, fluid W flows from compression chambers S1 and S2 towards nozzles 65 and 66 to the outer periphery Ra of radial R. Its flow direction hardly changes to axial (X) and flows almost towards the outer periphery Ra of radial R, and is ejected out of the shell 50 through the shell-side nozzles 63 and 64.

[0177] The fluid W, compressed in the compression chambers S1 and S2, is ejected outside the casing 50 through nozzles 65 and 66 and casing-side outlets 63 and 64, making pressure loss unlikely. Therefore, in the screw compressor 1, pressure loss of the fluid W can be suppressed.

[0178] The gate rotor chambers 59 and 61 that house the gate rotors 30 and 35 are typically arranged near the nozzles 65 and 66 in the axial direction X. The covers 91 and 93 that cover the gate openings 60 and 62 are also typically arranged near the nozzles 65 and 66 in the axial direction X. The fact that the housing-side nozzles 63 and 64 are covered by covers 91 and 93 along with the gate openings 60 and 62 means that the housing-side nozzles 63 and 64 are located near the nozzles 65 and 66 in the axial direction X.

[0179] By providing cover-side spray paths 94 and 97 that communicate with the housing-side spray outlets 63 and 64 in the covers 91 and 93, fluid W can flow from the housing 50 side to the cover 91 and 93 side.

[0180] Since the housing-side nozzles 63 and 64 are flush with the housing-side mounting surfaces 58a and 58b, the fluid W ejected from the housing-side nozzles 63 and 64 can be prevented from leaking through the gap between the housing-side mounting surfaces 58a and 58b and the covers 91 and 93 by using the first sealing member 92 to seal the space between them.

[0181] Since the casing-side nozzles 63 and 64 are located in the axial direction X, overlapping with the nozzles 65 and 66, they can be positioned closer to the nozzles 65 and 66 in the axial direction X. This helps to prevent the fluid W flowing from the compression chambers S1 and S2 toward the nozzles 65 and 66 to the outer peripheral side Ra of the radial R from changing its flow direction to the axial direction X before reaching the casing-side nozzles 63 and 64.

[0182] Since connecting paths 67 and 68 extend in a straight line, it is beneficial to suppress the pressure loss of the fluid W flowing in connecting paths 67 and 68.

[0183] By providing a silencer 96 on the nozzles 95 and 98, it is beneficial to suppress the noise caused by the fluid W flowing in the nozzles 95 and 98.

[0184] Since the retaining member 77 of the rear bearing bracket 73 is plate-shaped with the thickness direction t in the axial direction X, it is beneficial to reduce the size of the screw compressor 1 in the axial direction X.

[0185] By adjusting the opening C of nozzles S1 and S2 using slide valves 87 and 89, the apparent volume of compression chambers S1 and S2 can be easily adjusted.

[0186] Since the first housing side spray outlet 63 and the second housing side spray outlet 64 are located at different positions in the circumferential direction θ, the first housing side spray outlet 63 and the second housing side spray outlet 64 can be located between the first position Ka and the second position Kb in the axial direction X without interfering with each other.

[0187] Since the first compression chamber S1 and the second compression chamber S2 are separated from each other radially (R) rather than axially (X), it is advantageous to suppress the axial dimension of the screw compressor 1. In addition to the above structure, since the housing-side nozzles 63 and 64 are almost inseparable from the nozzles 65 and 66 axially, it is even more advantageous to suppress the axial dimension of the screw compressor 1.

[0188] When two or more shell side spray outlets 63 and 64 are provided, the above structure has a greater cost advantage compared to the case of providing only one shell side spray outlet.

[0189] Since the screw compressor 1 is a two-stage screw compressor, it can compress fluid W in two stages using the first compression chamber S1 and the second compression chamber S2.

[0190] <Second Implementation>

[0191] The screw compressor 1 according to the second embodiment will now be described. In the following description of the second embodiment, the same symbols are sometimes used for structures that are the same as those in the above embodiment, and detailed descriptions are omitted. Figure 13 The second embodiment is equivalent to Figure 3 The diagram, with the previous view showing screw compressor 1.

[0192] In this embodiment, the screw compressor 1 is not a two-stage compressor. The first ejector pipe 95 and the second ejector pipe 98 merge at a confluence point 99. One end of the confluence pipe 100 is connected to the confluence point 99. The first ejector pipe 95 and the second ejector pipe 98 communicate with the confluence pipe 100 at the confluence point 99. The other end of the confluence pipe 100 is connected, for example, to a condenser in the refrigerant circuit.

[0193] The pulsation U of the fluid W that reaches the confluence 99 from the first nozzle 65 via the first connecting path 67, the first housing-side nozzle 63, the first cover-side nozzle 94, and the first nozzle pipe 95 cancels out the pulsation U of the fluid W that reaches the confluence 99 from the second nozzle 66 via the second connecting path 68, the second housing-side nozzle 64, the second cover-side nozzle 97, and the second nozzle pipe 98.

[0194] In order to make the pulsations U of each fluid W cancel each other out, the pulsations U of each fluid W are opposite in phase.

[0195] In order to make the pulsations U of each fluid W cancel each other out (become opposite phases), the opening C of nozzles 65 and 66, the length and diameter of connecting passages 67 and 68, the diameter of shell-side nozzles 63 and 64, the length and diameter of cover-side nozzle passages 94 and 97, and the length and diameter of nozzle pipes 95 and 98 are adjusted.

[0196] A silencer 96 is provided on the first ejector pipe 95. A silencer 96 is provided on the second ejector pipe 98. A silencer 96 is provided on the confluence pipe 100.

[0197] The other structures are the same as in the first embodiment.

[0198] According to this embodiment, it is beneficial to suppress noise and vibration caused by the pulsation U of fluid W.

[0199] <Third Implementation Method>

[0200] The screw compressor 1 according to the third embodiment will now be described. In the following description of the third embodiment, the same symbols are sometimes used for structures that are the same as those in the above embodiments, and detailed descriptions are omitted. Figure 14 The cover-side spray paths 94 and 97 of the third embodiment are shown.

[0201] The cover-side ejection paths 94 and 97 include orifices 94a and 97a, tubes 94b and 97b, and cover-side insertion tubes 94c and 97c. The cover-side insertion tubes 94c and 97c of the cover-side ejection paths 94 and 97 are located closer to the inner circumferential side Rb of the radial direction R than the covers 91 and 93, and extend along the radial direction R.

[0202] The inner diameter of the cover-side insertion tubes 94c and 97c is inserted into the inner diameter of the housing-side nozzles 63 and 64. An O-ring 101, serving as a second sealing component, is provided on the outer periphery of the cover-side insertion tubes 94c and 97c. The housing-side nozzles 63 and 64 are sealed to the cover-side insertion tubes 94c and 97c by the O-ring 101.

[0203] The other structures are the same as in the first embodiment.

[0204] According to this embodiment, it is possible to suppress the leakage of fluid W ejected from the housing-side ejection outlets 63 and 64 to the outside before it reaches the cover-side ejection paths 94 and 97.

[0205] <Other Implementation Methods>

[0206] The side nozzles 63 and 64 of the housing may not be located at a position overlapping with the nozzles 65 and 66 in the axial direction X, or they may be offset in the axial direction X relative to the nozzles 65 and 66 within the range between the front position Ka and the rear position Kb.

[0207] The covers 91 and 93 and the side spray paths 94 and 97 may not be formed as a single unit, but rather the covers 91 and 93 may be composed of independent components.

[0208] The side spray outlets 63 and 64 of the casing can also be arranged in different positions from the gate openings 60 and 62. The side spray outlets 63 and 64 of the casing can also be left uncovered by the covers 91 and 93.

[0209] Connecting paths 67 and 68 may not extend in a straight line, but may bend along the axial direction X, radial direction R, or circumferential direction θ in the middle.

[0210] Alternatively, a cover can be used instead of the plate-shaped retaining component 77.

[0211] The first housing side spray outlet 63 and the second housing side spray outlet 64 can also be located at the same position in the circumferential direction θ, as long as they fall within the range between the front position Ka and the rear position Kb in the axial direction.

[0212] In the above embodiment, two compression chambers, a first compression chamber S1 and a second compression chamber S2, are provided as compression chambers, but the embodiment is not limited to this. There may be one compression chamber or more than three compression chambers.

[0213] The embodiments have been described above, but it should be understood that various changes can be made to the manner 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.

[0214] - Symbol Explanation -

[0215] O Central axis

[0216] X-axis

[0217] Xa Anterior side (first direction side)

[0218] Rear side of Xb (second direction side)

[0219] R radial

[0220] Ra peripheral (lateral)

[0221] Rb inner peripheral side (inner side)

[0222] V Vertical direction

[0223] Va (upper side)

[0224] Vb bottom (below)

[0225] θ circumferential direction

[0226] r gate radius

[0227] t Thickness direction

[0228] W Working fluid (fluid)

[0229] S1 First Compression Chamber

[0230] S2 Second Compression Chamber

[0231] Sm intermediate chamber

[0232] P1 First Pressure

[0233] P2 Second Pressure

[0234] Pm intermediate pressure

[0235] C Opening

[0236] Ka (first position)

[0237] Position after Kb (second position)

[0238] F Connecting Path

[0239] Fa inclined part

[0240] Fb lower end

[0241] A body of revolution

[0242] DA outermost diameter

[0243] D20 outermost diameter

[0244] D41 Outer diameter

[0245] G Oil storage chamber

[0246] G0 Oil Flour

[0247] g oil

[0248] U pulse

[0249] 1. Screw compressor

[0250] 10 axes

[0251] 20 Screw Rotor

[0252] 21 Screw groove

[0253] 22 Front Rotary Sealing Part

[0254] 23 Rear Rotary Sealing Part

[0255] 30 First brake rotor

[0256] 32 First gate

[0257] 35 Second brake rotor

[0258] 37 Second gate

[0259] 40 Electric Motor

[0260] 41. Electric motor rotor

[0261] 42 Motor stator

[0262] 50 Housing

[0263] 53. Partition wall (wall section)

[0264] 53b Connecting hole

[0265] 54 Electric Motor Room

[0266] 55. Cylindrical wall section

[0267] 55a Front fixed sealing part (partial)

[0268] 55b Rear Fixed Sealing Part (Partial)

[0269] 55c section

[0270] 55d section

[0271] 56 First Slit

[0272] 57 Second Slit

[0273] 58. Outer wall of the shell

[0274] 58a First housing side mounting surface

[0275] 58b Second housing side mounting surface

[0276] 59 First brake rotor chamber

[0277] 60 First gate opening

[0278] 61 Second brake rotor chamber

[0279] 62 Second gate opening

[0280] 63 First casing side spray outlet

[0281] 64 Second shell side spray outlet

[0282] 65 First nozzle

[0283] 65a Front end (first end)

[0284] 65b Rear end (second end)

[0285] 66 Second nozzle

[0286] 66a Front end (first end)

[0287] 66b Rear end (second end)

[0288] 67 First Connecting Road

[0289] 68 Second Connecting Road

[0290] 69a First Inlet

[0291] 69c Second Inlet

[0292] 73 Rear bearing bracket (bearing support)

[0293] 74 Rear bearing (bearing)

[0294] 77 Retaining components

[0295] 87 First slide valve

[0296] 89 Second slide valve

[0297] 91 First Cover

[0298] 92 Washer (First sealing component)

[0299] 93 Second Cover

[0300] 94 First cover side spray outlet

[0301] 94c Side-mounted insertion tube

[0302] 95 First Ejector Pipe

[0303] 96 Silencing components

[0304] 97 Second cover side spray outlet

[0305] 97c Side-mounted insertion tube

[0306] 98 Second ejector pipe

[0307] 99 Convergence Department

[0308] 100 Combination Pipe

[0309] 101 O-ring (second sealing component)

Claims

1. A screw compressor, characterized in that: The screw compressor includes a screw rotor (20), a brake rotor (30, 35), and a housing (50). The screw rotor (20) has screw grooves (21) and extends along the axial direction (X). The brake rotor (30, 35) has a brake (32, 37) that meshes with the screw groove (21). The housing (50) holds the screw rotor (20) in a rotatable position and covers the screw rotor (20) from the outer side (Ra) of the radial (R) direction orthogonal to the axial direction (X). The screw rotor (20), the brake rotor (30, 35) and the housing (50) form a compression chamber (S1, S2) for the compressed fluid (W). A housing side nozzle (63, 64) is formed on the outer wall portion (58) of the housing (50) located on the outer side (Ra) of the radial direction (R), and the fluid (W) is ejected from the housing side nozzle (63, 64). In the housing (50), the portion (55c, 55d) facing the compression chamber (S1, S2) is formed with nozzles (65, 66) that communicate with the side nozzles (63, 64) of the housing. The nozzle (65, 66) includes a first end (65a, 66a) located on a first direction side (Xa) in the axial direction (X) and a second end (65b, 66b) located on a second direction side (Xb) opposite to the first direction side (Xa) in the axial direction (X). The side nozzles (63, 64) of the housing are located between a first position (Ka) and a second position (Kb) in the axial direction (X). The first position (Ka) is a position located at a distance equal to the radius (r) of the gates (32, 37) from the first end (65a, 66a) toward the first direction side (Xa). The second position (Kb) is a position located at a distance equal to the radius (r) of the gates (32, 37) from the second end (65b, 66b) toward the second direction side (Xb). The housing-side nozzles (63, 64) are located in the radial direction (R) closer to the nozzles (65, 66) than the screw rotor (20). The brake rotors (30, 35) are housed within the brake rotor chambers (59, 61) located in the housing (50). A gate opening (60, 62) communicating with the gate rotor chamber (59, 61) is provided on the outer wall portion (58) of the housing. The side spray outlets (63, 64) of the housing and the gate openings (60, 62) are covered by caps (91, 93). The cover (91, 93) is provided with a cover-side spray path (94, 97) that communicates with the shell-side spray outlet (63, 64).

2. The screw compressor according to claim 1, characterized in that: The side nozzles (63, 64) of the housing are flush with the housing side mounting surfaces (58a, 58b) on the outer wall portion (58) of the housing where the covers (91, 93) are installed. The housing side mounting surfaces (58a, 58b) and the cover (91, 93) are sealed by a first sealing component (92).

3. The screw compressor according to claim 1, characterized in that: The cover-side spray outlet (94, 97) includes a cover-side insertion tube (94c, 97c) inserted into the housing-side spray outlet (63, 64). The shell-side nozzles (63, 64) and the cover-side insertion tubes (94c, 97c) are sealed by a second sealing component (101).

4. The screw compressor according to claim 1 or 2, characterized in that: The shell-side nozzles (63, 64) are located in the axial direction (X) at a position overlapping with the nozzles (65, 66).

5. The screw compressor according to claim 1 or 2, characterized in that: The housing (50) is provided with connecting passages (67, 68) that connect the housing side spray outlets (63, 64) to the nozzles (65, 66). The connecting paths (67, 68) extend in a straight line.

6. The screw compressor according to claim 1 or 2, characterized in that: Spray pipes (95, 98) are connected to the spray outlets (63, 64) on the side of the housing. A silencer (96) is provided on the ejector pipes (95, 98).

7. The screw compressor according to claim 1 or 2, characterized in that: The screw compressor includes a bearing support (73) and a retaining component (77). The bearing bracket (73) holds the bearing (74), and the bearing (74) supports the screw rotor (20). The retaining member (77) presses the bearing bracket (73) along the axial direction (X). The retaining member (77) is plate-shaped with the axial direction (X) as the thickness direction (t).

8. The screw compressor according to claim 1 or 2, characterized in that: The screw compressor includes slide valves (87, 89) that adjust the opening (C) of the nozzles (65, 66) by moving along the axial direction (X).

9. The screw compressor according to claim 1 or 2, characterized in that: The screw compressor includes a first brake rotor (30) and a second brake rotor (35) as the brake rotors (30, 35). The screw rotor (20), the first brake rotor (30), and the housing (50) form the first compression chamber (S1) which serves as the compression chamber (S1, S2). The screw rotor (20), the second brake rotor (35), and the housing (50) form the second compression chamber (S2) which is the compression chamber (S1, S2). A first housing side spray outlet (63) and a second housing side spray outlet (64) are formed on the outer wall portion (58) of the housing, serving as housing side spray outlets (63, 64). A first nozzle (65) serving as the nozzle (65, 66) is formed in the portion (55c) of the housing (50) facing the first compression chamber (S1). A second nozzle (66) serving as the nozzle (65, 66) is formed in the portion (55d) of the housing (50) facing the second compression chamber (S2). The first nozzle (65) is connected to the first housing side nozzle (63). The second nozzle (66) is connected to the second housing side nozzle (64). The first housing side spray outlet (63) and the second housing side spray outlet (64) are located at different positions in the circumferential direction (θ) of the screw rotor (20).

10. The screw compressor according to claim 1 or 2, characterized in that: The screw compressor includes a first brake rotor (30) and a second brake rotor (35) as the brake rotors (30, 35). The screw rotor (20), the first brake rotor (30), and the housing (50) form the first compression chamber (S1) which serves as the compression chamber (S1, S2). The screw rotor (20), the second brake rotor (35), and the housing (50) form the second compression chamber (S2) which is the compression chamber (S1, S2). A first housing side spray outlet (63) and a second housing side spray outlet (64) are formed on the outer wall portion (58) of the housing, serving as housing side spray outlets (63, 64). A first nozzle (65) serving as the nozzle (65, 66) is formed in the portion (55c) of the housing (50) facing the first compression chamber (S1). A second nozzle (66) serving as the nozzle (65, 66) is formed in the portion (55d) of the housing (50) facing the second compression chamber (S2). The first nozzle (65) is connected to the first housing side nozzle (63). The second nozzle (66) is connected to the second housing side nozzle (64). A first ejector pipe (95) is connected to the ejector outlet (63) on the first housing side. A second ejector pipe (98) is connected to the ejector outlet (64) on the second housing side. The first ejector pipe (95) and the second ejector pipe (98) merge at the confluence section (99). The screw compression mechanism is such that the pulsation (U) of the fluid (W) reaching the confluence (99) from the first nozzle (65) via the first housing-side nozzle (63) and the first ejector pipe (95) cancels out the pulsation (U) of the fluid (W) reaching the confluence (99) from the second nozzle (66) via the second housing-side nozzle (64) and the second ejector pipe (98).

11. The screw compressor according to claim 9, characterized in that: The first compression chamber (S1) compresses the fluid (W) at a first pressure (P1) to an intermediate pressure (Pm) that is higher than the first pressure (P1). The second compression chamber (S2) compresses the fluid (W) at the intermediate pressure (Pm) to a second pressure (P2) that is higher than the intermediate pressure (Pm). The fluid (W) flows in the order of the first compression chamber (S1), the first nozzle (65), the first housing side nozzle (63), the second compression chamber (S2), the second nozzle (66), and the second housing side nozzle (64).

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