screw compressor

Abstract

The screw compressor for compressing the working medium of the present invention includes: a first screw rotor and a second screw rotor for drawing in the working medium and discharging it after compression; a first bearing that rotatably supports one end of the first screw rotor connected to the rotating shaft of a power source; a housing for housing the first screw rotor and the first bearing; a shaft seal component disposed on the opposite side of the toothed portion of the first screw rotor relative to the first bearing inside the housing, sealing the through hole of the housing through which the shaft portion of the first screw rotor connected to the output shaft of the power source is inserted; a partition wall inside the housing that isolates the first bearing from the shaft seal component; and a fluid supply path formed in the housing, having a first fluid supply port for supplying lubricating fluid to the first bearing and a second fluid supply port for supplying lubricating fluid to the shaft seal component.

Description

Technical Field

[0001] This invention relates to screw compressors, specifically compressors suitable for use in screw compressors with a liquid supply mechanism. Background Technology

[0002] In the prior art, the oil-cooled screw compressor disclosed in Patent Document 1 is known as a screw compressor. The screw compressor has a structure that includes an oil supply hole for supplying lubricating oil to a space housing the suction bearing and the mechanical seal, a first recovery hole formed in the partition wall between the screw rotor and the suction-side bearing, and a second recovery hole bypassing the first recovery hole. These first and second recovery holes also open into the compressed air intake passage.

[0003] With this structure, in the screw compressor disclosed in Patent Document 1, a portion of the lubricating oil is recovered via a second recovery hole, and the amount of lubricating oil in the suction-side bearing is kept to the minimum required for lubrication, thereby reducing the agitation loss of the suction-side bearing.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2002-21758 Summary of the Invention

[0007] The technical problem that the invention aims to solve

[0008] However, in the screw compressor disclosed in Patent Document 1, a portion of the lubricating oil accumulated in the space housing the suction-side bearing and the mechanical seal passes through the suction-side bearing and is recovered to the first recovery hole to complete the bearing lubrication.

[0009] Therefore, the problem is that, in principle, the suction side bearing is a structure that agitates the lubricating oil accumulated in the space and agitates the lubricating oil passing through the suction side bearing. Therefore, the agitation loss caused by agitating the lubricating oil accumulated in the space is relatively large, which becomes the main reason for the reduction in compressor performance.

[0010] This invention was made in consideration of the above-mentioned problems, and proposes a highly efficient screw compressor with high reliability that can effectively prevent performance degradation as a compressor.

[0011] Technical solutions for solving technical problems

[0012] To address this issue, the screw compressor for compressing the working medium in this invention comprises: a first screw rotor and a second screw rotor for drawing in the working medium and discharging it after compression; a first bearing that rotatably supports one end of the first screw rotor connected to the rotating shaft of a power source; a housing housing the first screw rotor and the first bearing; a shaft seal component disposed opposite to the toothed portion of the first screw rotor relative to the first bearing inside the housing, sealing the through hole of the housing through which the shaft portion of the first screw rotor connected to the output shaft of the power source is inserted; a partition wall inside the housing separating the first bearing and the shaft seal component; and a fluid supply path formed in the housing, having a first fluid supply port for supplying lubricating fluid to the first bearing and a second fluid supply port for supplying lubricating fluid to the shaft seal component.

[0013] As a result, the appropriate amount of lubricant can be supplied independently to the shaft seal component and the first bearing. This suppresses lubricant churning losses in the first bearing caused by excessive lubricant supply.

[0014] Invention Effects

[0015] According to the present invention, a screw compressor with high reliability and high efficiency can be realized. Attached Figure Description

[0016] Figure 1 This is a horizontal cross-sectional view showing the structure of the male rotor side in the screw compressor of the first embodiment.

[0017] Figure 2 This is a vertical cross-sectional view showing the structure of the male rotor side in the screw compressor of the first embodiment.

[0018] Figure 3 This is a vertical cross-sectional view showing the structure of the liquid supply path on the male rotor side of the screw compressor in the first embodiment.

[0019] Figure 4 This is a vertical cross-sectional view showing the structure of the female rotor side in the screw compressor of the first embodiment.

[0020] Figure 5 This is a conceptual diagram illustrating the external path of the lubricating fluid injected into the screw compressor of the first embodiment.

[0021] Figure 6 This is a vertical cross-sectional view showing the structure of the male rotor side in the screw compressor of the second embodiment.

[0022] Figure 7This is a vertical cross-sectional view showing the structure of the male rotor side in the screw compressor of the third embodiment.

[0023] Figure 8 This is a vertical cross-sectional view showing the structure of the male rotor side in the screw compressor of the fourth embodiment. Detailed Implementation

[0024] Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[0025] (1) First implementation method

[0026] Figure 1 and Figure 2 The screw compressor 1 represents the first embodiment. Figure 1 yes Figure 2 The CC-direction view (horizontal section view) in the middle, Figure 2 yes Figure 1 View AA (vertical section view) in the middle.

[0027] like Figure 1 and Figure 2 As shown, the screw compressor 1 of this embodiment is configured to have a male rotor 2 and a female rotor 3 as a pair of screw rotors, and a housing 4 for housing the male rotor 2 and the female rotor 3.

[0028] The male rotor 2 is configured to include: a toothed portion 2A having a plurality of spirally extending teeth (blades); and at one end of the toothed portion 2A along the rotor axial direction ( Figure 1 and Figure 2 On the left side, the same applies below. ) Formed on the suction side shaft portion 2B; on the other end side of the rotor axial direction of the toothed portion 2A ( Figure 1 and Figure 2 The same applies below. ) Formed on the right side. The suction side shaft 2B of the male rotor 2 is rotatably supported by the suction side bearing (hereinafter referred to as the first suction side bearing) 5, and the discharge side shaft 2C of the male rotor 2 is rotatably supported by the discharge side bearing (hereinafter referred to as the first discharge side bearing) 6.

[0029] Similarly, the female rotor 3 is configured to include: a toothed portion 3A having a plurality of teeth that mesh with the teeth of the male rotor 2; an intake-side shaft portion 3B formed at one end of the toothed portion 3A in the rotor axial direction; and a discharge-side shaft portion 3C formed at the other end of the toothed portion 3A in the rotor axial direction. The intake-side shaft portion 3B of the female rotor 3 is rotatably supported by an intake-side bearing (hereinafter referred to as the second intake-side bearing) 7, and the discharge-side shaft portion 3C of the female rotor 3 is rotatably supported by a discharge-side bearing (hereinafter referred to as the second discharge-side bearing) 8.

[0030] The suction side shaft 2B of the male rotor 2 passes through the housing 4 and is connected to the rotating shaft of the electric motor (not shown). Thus, by driving the electric motor, the male rotor 2 and the rotating shaft of the electric motor can be rotated together, and at the same time, the female rotor 3 and the male rotor 2 can also be rotated together.

[0031] The housing 4 is configured to include: a main housing 4A; a discharge-side housing 4B connected to the other end of the rotor axis of the main housing 4A; and an intake-side housing 4D connected to one end of the rotor axis of the main housing 4A via an intake-side partition wall 4C.

[0032] The discharge-side housing 4B has independently provided first discharge-side bearing receiving space 9A and second discharge-side bearing receiving space 9B. The first discharge-side bearing 6 is housed in the first discharge-side bearing receiving space 9A, and the second discharge-side bearing 8 is housed in the second discharge-side bearing receiving space 9B. Furthermore, in the discharge-side housing 4B, toothed portions 2A and 3A are formed on the radially outer side of the rotor, relative to the male rotor 2 or female rotor 3. Figure 2 The discharge outlet 10 (on the lower side); and the discharge path 11 connecting the discharge outlet 10 to the chamber 12 described later.

[0033] A chamber 12 is formed in the main housing 4A to accommodate the toothed portion 2A of the male rotor 2 and the toothed portion 3A of the female rotor 3. The chamber 12 is a space with two cylindrical holes that partially overlap, used to accommodate the toothed portion 2A of the male rotor 2 and the toothed portion 3A of the female rotor 3 in a tooth-meshing state.

[0034] The working chamber is formed by the inner wall of chamber 12, the tooth grooves of the male rotor 2, and the tooth grooves of the female rotor 3. The working chamber is formed such that its volume gradually decreases as it moves from one end of the rotor axis to the other. As a result, the working medium, such as air, drawn in from the intake port 13 is compressed within the working chamber and discharged from the outlet port 10 via the discharge path 11.

[0035] The intake port 13 is formed on the radially outer side of the rotor teeth 2A and 3A of the female rotor 3, which are located in the main housing 4A. Figure 2 (The upper side). The suction port 13 is connected to the working chamber via the suction space 14, and the working medium sucked in from the suction port 13 is supplied to the working chamber via the suction space 14.

[0036] On one end face of the rotor axial direction of the main housing 4A, a cylindrical first suction side bearing receiving space 15 and a cylindrical second suction side bearing receiving space 16 are formed. The first suction side bearing 5 is embedded in the first suction side bearing receiving space 15, and the second suction side bearing 7 is embedded in the second suction side bearing receiving space 16.

[0037] Additionally, the main housing 4A includes: a first bearing connecting space 17, which is slightly smaller in diameter than the first suction-side bearing receiving space 15 and connects the first suction-side bearing receiving space 15 and the suction space 14; and a second bearing connecting space 18, which is slightly smaller in diameter than the second suction-side bearing receiving space 16 and connects the second suction-side bearing receiving space 16 and the suction space 14.

[0038] Furthermore, a suction-side partition wall 4C is fixed to one end face of the main housing 4A on the rotor axial side, and a suction-side housing 4D is fixed to the end of the suction-side partition wall 4C on the rotor axial side. In the suction-side housing 4D, on the opposite side to the suction-side partition wall 4C, a shaft sealing space 20 is formed, communicating with the through hole 19 into which the suction-side shaft portion 2B of the male rotor 2 is inserted. A shaft sealing component 21 for sealing the through hole 19 is disposed in the shaft sealing space 20.

[0039] Furthermore, the casing 4 of this screw compressor 1 is provided with a first working chamber liquid supply port 22 that communicates with the working chamber inside the chamber 12, through which liquid can be injected into the working chamber. In addition, a first suction side liquid supply port 23 is provided on the suction port 13 side of the casing 4, and a first discharge side liquid supply port 24 is provided on the discharge port 10 side of the casing 4. Liquid can be injected into the shaft seal space 20 and the first suction side bearing receiving space 15 through the first suction side liquid supply port 23, and liquid can be injected into the first discharge side bearing receiving space 9A through the first discharge side liquid supply port 24.

[0040] The injection of liquid into the working chamber, shaft seal space 20, first intake-side bearing receiving space 15, and first discharge-side bearing receiving space 9A is for the purpose of cooling the mechanical components and compressed air, lubricating the first intake-side bearing 5 and the first discharge-side bearing 6, and improving the sealing performance based on the shaft seal component 21. Oil or water can be used as the liquid injected at this time. Hereinafter, this liquid will also be referred to as lubricating fluid.

[0041] The lubricant injected into the first suction side supply port 23 is released into the shaft seal space 20 through the first supply port 25 inside the housing 4, and into the first suction side bearing receiving space 15 through the second supply port 26.

[0042] Figure 3 This diagram illustrates the flow path of the lubricant supplied to the first suction-side bearing 5 and the shaft seal component 21 within the housing 4. The arrows in the diagram indicate the direction of lubricant supply. Figure 3As shown, a first liquid supply path 27 is provided inside the housing 4, connecting the first suction-side liquid supply port 23 with the first and second liquid supply ports 25 and 26. In addition, the first liquid supply path 27 branches into first and second branch paths 27A and 27B in the middle, with the first branch path 27A connected to the first liquid supply port 25 and the second branch path 27B connected to the second liquid supply port 26.

[0043] In this configuration, the first supply port 25 opens into the shaft seal component 21 disposed within the shaft seal space 20, thereby allowing lubricant injected into the housing 4 from the first suction side supply port 23 and flowing into the first branch passage 27A to be released from the first supply port 25 and supplied to the shaft seal component 21. Furthermore, the shaft seal space 20 is connected to the suction space 14 via a bypass passage 28, thereby allowing lubricant injected into the shaft seal space 20 to be discharged into the suction space 14 via the bypass passage 28.

[0044] On the other hand, the second liquid supply port 26 opens into the first suction side bearing 5 housed in the first suction side bearing housing space 15, thereby releasing the lubricant injected into the housing 4 from the first suction side liquid supply port 23 and flowing into the second branch 27B from the second liquid supply port 26 and supplying it to the first suction side bearing 5 from the male rotor 2 side.

[0045] In this case, since the first suction-side bearing 5 is partially exposed in the suction space 14 via the first bearing communication space 17 of the main housing 4A, the lubricant supplied to the first suction-side bearing 5 from the second supply port 26 flows out into the suction space 14 via the first bearing communication space 17. This lubricant then merges with the lubricant flowing into the suction space 14 via the bypass communication passage 28, and together with the working medium flowing into the suction space 14 from the suction port 13, it is transported to the working chamber.

[0046] Here, the churning loss of the lubricant in the first suction side bearing 5 is considered. In this embodiment, the first suction side bearing 5 is assumed to be a roller bearing, but it is not limited to this; the first suction side bearing 5 may also be a ball bearing or other rolling bearings.

[0047] Normally, when a rolling bearing rotates in lubricating fluid, the rotating element inside the bearing rotates while pushing the lubricating fluid away, thus experiencing fluid resistance. Furthermore, in this embodiment, since the lubricating fluid supplied to the first suction-side bearing 5 is configured to be constantly replaced, the rotating element needs to accelerate the flow of newly introduced lubricating fluid. Together, these factors contribute to turbulence losses.

[0048] In this embodiment, according to Figure 3 It can be seen that the portion where the first suction-side bearing 5 is located is higher than the lowest end of the suction space 14, making it a structure that prevents lubricant from accumulating. Additionally, as... Figure 3When the screw compressor 1 is configured such that the male rotor 2 and the female rotor 3 are horizontal, the first bearing communication space 17 is formed in such a way that the lowest end of the first bearing communication space 17 is lower than the lowest end of the inner diameter of the outer ring of the first suction side bearing 5. Therefore, it is a structure that makes it easy to discharge the lubricating fluid in the rotating track of the first suction side bearing 5 into the suction space 14.

[0049] Furthermore, for example, if the second supply port 26 is formed on the suction-side partition wall 4C side, the lubricant supplied to the first suction-side bearing 5 via the second supply port 26 needs to pass through the rotating body track of the first suction-side bearing 5 in order to flow out to the suction space 14 side, thus increasing the churning loss accordingly. In contrast, in this embodiment, since the second supply port 26 is formed in such a way that lubricant can be supplied from the male rotor 2 side relative to the first suction-side bearing 5, all the lubricant supplied to the first suction-side bearing 5 does not need to pass through the rotating body track of the first suction-side bearing 5. Therefore, it can be said that this screw compressor 1 has a structure with low churning loss of lubricant in the rotating body track of the first suction-side bearing 5.

[0050] Next, the amount of lubricant supplied to the shaft seal component 21 and the first suction-side bearing 5 will be explained. As described in Patent Document 1 above, the necessary amount of lubricant in the first suction-side bearing 5 is usually less than the necessary amount in the shaft seal component 21 such as a mechanical seal.

[0051] In this respect, in the screw compressor 1 of this embodiment, since the first suction side bearing housing space 15, which houses the first suction side bearing 5, and the shaft sealing space 20, which is equipped with the shaft sealing component 21, are separated by the suction side partition wall 4C, the first liquid supply port 25, which supplies lubricating fluid to the shaft sealing component 21, and the second liquid supply port 26, which supplies lubricating fluid to the first suction side bearing 5, are independently provided. Therefore, it is possible to supply appropriate amounts of lubricating fluid to the shaft sealing component 21 and the first suction side bearing 5 respectively.

[0052] The distribution of lubricant supply to the shaft seal component 21 and the first suction-side bearing 5 can be determined based on the pressure loss of the first supply path 27. Specifically, it can be determined based on the lengths and hydraulic diameters of the first and second branch paths 27A and 27B, and the diameters of the first and second supply ports 25 and 26. In this embodiment, as described above, the amount of lubricant required for the shaft seal component 21 is greater than the amount of lubricant required for the first suction-side bearing 5. Therefore, the lengths and hydraulic diameters of the first and second branch paths 27A and 27B, and the diameters of the first and second supply ports 25 and 26 are set in such a way that the pressure loss from the first suction-side supply port 23 to the first supply port 25 is smaller than the pressure loss from the first suction-side supply port 23 to the second supply port 26.

[0053] Figure 4 yes Figure 1 The BB-direction view (vertical section view). In the main housing 4A, a second working chamber liquid supply port 30 is provided, which communicates with the working chamber in the chamber 12, and is configured to supply lubricating fluid from the outside of the screw compressor 1 to the working chamber through the second working chamber liquid supply port 30.

[0054] Furthermore, a second discharge side liquid supply port 31 is formed in the discharge side housing 4B, which is configured to supply lubricating fluid to the second discharge side bearing 8 disposed in the second discharge side bearing receiving space 9B via the second discharge side liquid supply port 31.

[0055] Furthermore, a second suction-side liquid supply port 32 is formed on the radially outer side of the rotor in the suction-side housing 4D, and a third liquid supply port 33 is provided in the main housing 4A toward the second suction-side bearing 7 housed in the second suction-side bearing receiving space 16. The third liquid supply port 33 communicates with the second suction-side liquid supply port 32 via a second liquid supply path 34 formed inside the housing 4. Thus, by injecting lubricating fluid into the screw compressor 1 through the second suction-side liquid supply port 32, the lubricating fluid can be supplied to the second suction-side bearing 7 from the third liquid supply port 33 via the second liquid supply path 34.

[0056] In this case, since the second suction-side bearing 7 is partially exposed to the suction space 14 via the second bearing communication space 18 of the main housing 4A, the lubricant supplied to the second suction-side bearing 7 from the second suction-side liquid supply port 32 via the second liquid supply path 34 flows out to the suction space 14 via the second bearing communication space 18, and then is transported to the working chamber together with the working medium flowing into the suction space 14 from the suction port 13.

[0057] By constructing a second fluid supply path 34 in this way, based on the same principle as the churning loss of the lubricant in the first suction side bearing 5, the churning loss of the lubricant in the second suction side bearing 7 can be minimized.

[0058] Furthermore, the second chamber liquid supply port 30, the second suction side liquid supply port 32, and the second discharge side liquid supply port 31 can be respectively connected to the aforementioned... Figure 2 The corresponding liquid supply ports among the first chamber liquid supply port 22, the first suction side liquid supply port 23, and the first discharge side liquid supply port 24 are formed independently, or they can be formed in the same location. That is, the first and second chamber liquid supply ports 22 and 30, the first and second suction side liquid supply ports 23 and 32, and the first and second discharge side liquid supply ports 24 and 31 can be the same liquid supply port.

[0059] Figure 5 This indicates the external path of the lubricating fluid injected into the screw compressor 1 of this embodiment. The lubricating fluid injected into the screw compressor 1, while mixed with the working medium compressed by the screw compressor 1, exits from the discharge port 10 (…). Figure 2 , Figure 4 The lubricant is discharged. Furthermore, the lubricant is separated from the compressed working medium by the oil separator 40, and after being cooled by the cooler 41, it is supplied to the first and second chamber supply ports 22 and 30 via the oil filter (and check valve) 42. Figure 2 , Figure 4 The liquid is injected into the working chamber through the first and second working chamber supply ports 22 and 30, respectively.

[0060] In addition, the lubricating fluid is branched after passing through the oil filter 42 and is also supplied to the first and second suction side supply ports 23 and 32. Figure 2 , Figure 4 ) and / or the first and second discharge side supply ports 24, 31 ( Figure 2 , Figure 4 It can also be supplied to the shaft seal space 20 through the first suction side liquid supply port 23. Figure 2 Shaft seal component 21 () Figure 2 ), and / or the first suction side bearing housing space 15 ( Figure 2 The first suction side bearing 5, the second suction side bearing 7, and the first discharge side bearing housing space 9A are all located within the first suction side bearing housing space 15. Figure 1 The first discharge side bearing 6 () Figure 1 ), and the housing space 9B for the bearing on the second discharge side ( Figure 1 The second discharge side bearing 8 () Figure 1 Furthermore, the branches of lubricants are not limited to... Figure 5 The screw compressor 1 shown can be external or internal to the casing 4 of the screw compressor 1.

[0061] As shown in the structure above, in the screw compressor 1 of this embodiment, the first suction side bearing housing space 15, which houses the first suction side bearing 5, and the shaft sealing space 20, which is equipped with the shaft sealing component 21, are separated by the suction side partition wall 4C. The first supply port 25 for supplying lubricating fluid to the shaft sealing component 21 and the second supply port 26 for supplying lubricating fluid to the first suction side bearing 5 are independently provided. Therefore, an appropriate amount of lubricating fluid can be supplied to the shaft sealing component 21 and the first suction side bearing 5 independently. Therefore, according to this screw compressor 1, the churning loss of lubricating fluid in the first suction side bearing 5 caused by excessive lubricating fluid supply can be suppressed, and a highly reliable and efficient screw compressor can be realized.

[0062] Furthermore, in this screw compressor 1, since a second fluid supply port 26 can be formed to supply lubricating fluid to the first suction-side bearing 5 from the male rotor 2 side, all the lubricating fluid supplied to the first suction-side bearing 5 does not need to pass through the rotating body track section of the first suction-side bearing 5, which undergoes rotational motion. Therefore, according to this screw compressor 1, a screw compressor with lower agitation losses of the lubricating fluid in the first suction-side bearing 5 and higher efficiency can be achieved.

[0063] (2) Second Implementation

[0064] to and Figure 2 The corresponding parts are indicated by the same reference numerals. Figure 6 The figure shows the vertical cross-section of the screw compressor 50 of the second embodiment. In this screw compressor 50, the bypass connecting passage 52 is formed in the housing 51 (suction-side housing 50D, suction-side partition wall 50C and main housing 50A) in a manner that connects the shaft seal space 20 and the chamber 12, which is different from the screw compressor 1 of the first embodiment.

[0065] Therefore, in this screw compressor 50, the first working chamber liquid supply port 22 is not provided in the main housing 50A. Figure 2 The lubricant supplied to the shaft seal component 21 in the shaft seal space 20 via the bypass connection 52 is discharged into the chamber 12 through the bypass connection 52 and the path connecting the first working chamber's liquid supply port 22 to the chamber 12.

[0066] The screw compressor 50 of this embodiment, having the above-described structure, similarly to the screw compressor 1 of the first embodiment, is able to supply sufficient lubricant to the first and second suction-side bearings 5, 7 or the shaft seal component 21, and can suppress churning losses in the first and second suction-side bearings 5, 7 to a low level. Therefore, based on this embodiment, a highly reliable and efficient screw compressor can be provided.

[0067] (3) Third implementation method

[0068] to and Figure 2 The corresponding parts are indicated by the same reference numerals in the attached diagram. Figure 7 The figure shows the vertical cross-section of the screw compressor 60 of the third embodiment. This screw compressor 60 is constructed in the same manner as the screw compressor 1 of the first embodiment, except that the position of the second liquid supply port 62 is different.

[0069] In fact, in the screw compressor 60 of this embodiment, the second liquid supply port 62 is provided in the suction side partition wall 60C in such a way that lubricating fluid can be supplied from the suction side partition wall 60C side relative to the first suction side bearing 5, and a second branch 63B of the first liquid supply path 63 is provided in the suction side housing 60D and the suction side partition wall 60C in such a way that the first liquid supply port 62 is connected to the first suction side liquid supply port 23.

[0070] Therefore, in this screw compressor 60, the structure in which the lubricating fluid supplied from the second liquid supply port 62 to the first suction side bearing 5 passes through the rotating body track of the first suction side bearing 5, which is in a rotating motion, results in greater stirring loss in the first suction side bearing 5 compared to the screw compressor 1 of the first embodiment.

[0071] However, in this screw compressor 60, since the first liquid supply port 62 is provided on the suction side partition wall 60C side relative to the first suction side bearing 5, the part for providing the first liquid supply port opposite to the first suction side bearing 5 does not need to be provided in the main housing 4A. Correspondingly, the opening area of ​​the first bearing communication space 17 can be increased, so the lubricant is less likely to remain in the rotating body track of the first suction side bearing 5, and the stirring loss in the first suction side bearing 5 can be suppressed to a lower level.

[0072] The screw compressor 60 of this embodiment, having the above-described structure, similarly to the screw compressor 1 of the first embodiment, can supply sufficient lubricant to the first suction-side bearing 5 and the shaft seal component 21, and can minimize churning losses in the first suction-side bearing 5. Therefore, based on this embodiment, a highly reliable and efficient screw compressor can also be provided.

[0073] (4) Fourth Implementation Method

[0074] to and Figure 3 The corresponding parts are labeled with the same reference numerals. Figure 8 The figure shows a vertical cross-section of a portion of the structure of the screw compressor 70 according to the fourth embodiment. Compared with the screw compressor 1 of the first embodiment, the through hole 72 formed in the suction-side partition wall 71 for inserting the suction-side shaft portion 2B of the male rotor 2 is larger. Apart from this, the screw compressor 70 is configured in the same way as the screw compressor 1 of the first embodiment.

[0075] Therefore, in the screw compressor 70 of this embodiment, most of the lubricating fluid supplied to the first suction side bearing 5 via the second liquid supply port 26 flows out into the suction space 14, while the remaining part flows into the shaft seal space 20 through the first suction side bearing 5 and through the through hole 72. Afterward, it merges with the lubricating fluid supplied to the shaft seal space 20 via the first liquid supply port 25 and is discharged into the suction space 14 via the bypass connecting passage 28.

[0076] In this screw compressor 70, a portion of the lubricant supplied from the second liquid supply port 26 to the first suction side bearing 5 is configured to pass through the rotating body track of the first suction side bearing 5, which is in rotational motion. However, since the lubricant passing through the rotating body track of the first suction side bearing 5 quickly flows into the shaft seal space 20 through the through hole 72, the lubricant is less likely to stagnate in the rotating body track of the first suction side bearing 5. Accordingly, compared with the screw compressor 1 of the first embodiment, the stirring loss in the first suction side bearing 5 can be suppressed to a lower level.

[0077] The screw compressor 70 of this embodiment, having the above-described structure, can supply sufficient lubricant to the first suction-side bearing 5 and the shaft seal component 21, and can suppress stirring losses in the first suction-side bearing 5 to a lower extent compared to the screw compressor 1 of the first embodiment. Therefore, based on this embodiment, a screw compressor with high reliability and higher efficiency can be provided.

[0078] (5) Other implementation methods

[0079] Furthermore, in the first to fourth embodiments described above, the case in which only the suction side shaft of the male rotor 2 is connected to the rotating shaft of the electric motor that serves as the power source has been described. However, the present invention is not limited to this. The present invention can also be applied to screw compressors in which the suction side bearing of the female rotor 3, or even the male rotor 2, is connected to the rotating shaft of the power source instead of the male rotor 2, can also be connected to the rotating shaft of the power source.

[0080] Furthermore, in the first to fourth embodiments described above, the case in which the liquid supply path (first branch path) connected to the first liquid supply port and the liquid supply path (second branch path) connected to the second liquid supply port are branched inside the housing has been described. However, the present invention is not limited to this, and these liquid supply paths may also be formed separately (the liquid supply ports from the outside are formed separately).

[0081] Furthermore, in the third embodiment described above, the second fluid supply port 62 was provided in the suction-side partition wall 60C in such a way that lubricant could be supplied from the suction-side partition wall 60C side relative to the first suction-side bearing 5. However, the present invention is not limited to this. Regarding the second suction-side bearing 7, in order to also be able to supply lubricant from the suction-side partition wall 60C side, regarding... Figure 6 Alternatively, the third liquid supply port 26 mentioned above can be set in the suction-side partition wall 60C.

[0082] Industrial availability

[0083] This invention is widely applicable to screw compressors of various structures that compress working media.

[0084] Explanation of reference numerals in the attached figures

[0085] 1, 50, 60, 70… Screw compressor, 2… Male rotor, 2A, 3A… Toothed section, 2B, 3B… Suction side shaft section, 2C, 3C… Discharge side shaft section, 3… Female rotor, 4, 51… Housing, 5, 7… Suction side bearing, 6, 8… Discharge side bearing, 9A, 9B… Discharge side bearing housing space, 10… Discharge outlet, 12… Chamber, 13… Suction inlet, 14… Suction space, 15, 16… Suction… Side bearing receiving space, 17, 18, 72...bearing connecting space, 19...through hole, 20...shaft seal space, 21...shaft seal component, 22, 30...working chamber liquid supply port, 23, 32...suction side liquid supply port, 24, 31...discharge side liquid supply port, 25, 26, 33, 62...liquid supply port, 27, 34, 63...liquid supply path, 27A, 27B, 63A, 63B...branch path, 28, 52...bypass connecting path.

Claims

1. A screw compressor for compressing a working medium, characterized in that, include: First screw rotor and second screw rotor for sucking in the working medium and compressing it before discharging it; A first bearing rotatably supports the first screw rotor, which is connected at one end to the rotating shaft of the power source. A housing for accommodating the first screw rotor and the first bearing; A shaft seal component is disposed on the opposite side of the toothed portion of the first screw rotor relative to the first bearing inside the housing, and seals the through hole of the housing through which the shaft portion of the first screw rotor, which is connected to the output shaft of the power source, is inserted. A partition wall inside the housing that separates the first bearing and the shaft seal component; and A fluid supply path is formed in the housing, having a first fluid supply port for supplying lubricant to the first bearing and a second fluid supply port for supplying lubricant to the shaft seal component.

2. The screw compressor as described in claim 1, characterized in that: The shaft seal component is disposed within a first space formed in the housing. The first bearing is disposed within the second space formed in the housing. The toothed portion of the first screw rotor, which is connected at one end to the rotating shaft of the power source, is housed within a third space formed in the housing. The first space and the second space are separated by the partition wall. The first space is connected to the third space via a bypass path. The lubricant supplied to the first space is discharged to the third space via the bypass connection.

3. The screw compressor as described in claim 1, characterized in that: The first fluid inlet is provided in the housing in such a way that it can supply the lubricant to the first bearing from the first screw rotor side.

4. The screw compressor as described in claim 2, characterized in that: It has a connected space that connects the second space and the third space. The lubricant supplied to the first bearing can be discharged to the third space through the communicating space.

5. The screw compressor as described in claim 4, characterized in that: When the first screw rotor and the second screw rotor are set to be horizontal, the connecting space is formed such that the lowest end of the connecting space is lower than the lower end of the inner diameter of the outer ring of the first bearing.

6. The screw compressor as described in claim 1, characterized in that, include: The second bearing, like the one-end side of the rotating shaft of the first screw rotor connected to the power source, rotatably supports one end side of the second screw rotor; and A third fluid supply port, disposed in the housing, is used to supply the lubricating fluid to the second bearing. The third fluid supply port is formed in the housing in such a way that it can supply the lubricant to the second bearing from one side of the second screw rotor.

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