Screw compressor

Abstract

The invention provides a screw compressor with a liquid supply mechanism. The liquid supply mechanism can supply liquid which is sufficiently formed into tiny liquid drops to an air compression chamber. This screw compressor (100) is provided with a screw rotor (1) and a housing (4) that houses the screw rotor, and is provided with a liquid supply mechanism (40) that supplies a liquid (50) into a compression chamber (13) formed inside the housing, and the liquid supply mechanism (40) has a structure that has a recess (41) that opens on the inner surface (4a) of the housing. In a first region (42) on the bottom side of the recess (41), a vertical wall surface (422) along the depth direction of the recess and an outlet (441) of a liquid introduction flow path (44) that opens toward the vertical wall surface are disposed, and in a second region (43) on the inner surface side of the housing of the recess that is continuous with the first region (42). A bent surface (431) which is bent at a boundary portion with the vertical wall surface and is continuous in a direction away from an outlet of the liquid introduction flow path is disposed.

Description

Technical Field

[0001] This invention relates to screw compressors. Background Technology

[0002] Screw compressors are devices that compress gases such as air. A screw compressor is a device that generates compressed gas by engaging two screw-shaped male and female rotors. In screw compressors, to improve gas compression efficiency, a liquid supply mechanism for injecting liquids such as oil is provided in the gas compression chamber formed within the housing that houses the male and female screw rotors. The liquid injected into the gas compression chamber from the liquid supply mechanism serves to cool the compressed gas based on heat exchange and to reduce gas leakage from the gaps between the screw rotors and between the screw rotors and the housing.

[0003] The prior art regarding the liquid supply mechanism in the gas compression chamber is described.

[0004] One method for atomizing liquid into tiny droplets during liquid ejection is the use of liquid collision energy.

[0005] Patent Document 1 below also discloses a liquid supply mechanism, wherein the liquid supply nozzle has a pair of injection holes and a groove, the pair of injection holes causing the injected liquid to collide and spread in a planar manner, and the groove has a first inclined surface and a second inclined surface that gradually approach each other as they move toward the bottom as sidewalls, and the liquid is atomized into tiny droplets by the collision of the liquid injected from the pair of injection holes.

[0006] In addition, Patent Document 2 below also discloses a liquid supply mechanism technology, which sets up an inclined surface for liquid collision in a location other than the oil supply hole space. The liquid flowing out from the inclined throttling hole collides with the inclined surface to form a fan-shaped spray pattern, thereby turning the liquid into tiny droplets.

[0007] Existing technical documents

[0008] Patent documents

[0009] Patent Document 1: Japanese Patent Application Publication No. 2021-85389

[0010] Patent Document 2: US2019 / 0093659A1 Summary of the Invention

[0011] The problem that the invention aims to solve

[0012] In order to achieve cooling of compressed gas and reduce gas leakage in the gaps between the screw rotors and between the screw rotor and the housing through a liquid supply mechanism, it is necessary to atomize the liquid ejected from the liquid injection nozzle into tiny droplets and supply it to the air compression space. However, the technologies in Patent Documents 1 and 2 have the following problems.

[0013] As shown in Patent Document 1, in a method of ejecting liquid from a pair of injection holes and causing them to collide, a liquid film is initially formed by the collision, and then micro-droplets begin to form from the leading edge of the liquid film. Therefore, the splitting length from when the liquid is ejected from the injection holes to when it becomes micro-droplets is extended, resulting in the problem that the liquid film, in its state before micro-droplet formation, comes into contact with the rotor, making it impossible to achieve sufficient micro-droplet formation.

[0014] In Patent Document 2, an inclined surface for liquid collision is set in a location other than the oil supply hole space. Similar to Patent Document 1, it contacts the rotor in the state of a liquid film, which presents the problem that it is impossible to achieve sufficient micro-dropletization.

[0015] The present invention was made in view of the above-mentioned problems, and its object is to provide a screw compressor having a liquid supply mechanism capable of supplying a liquid that is sufficiently micro-dropletized into an air compression chamber.

[0016] Methods for solving problems

[0017] The screw compressor of the present invention, which solves the above-mentioned problems, includes a screw rotor and a housing for housing the screw rotor, and is provided with a liquid supply mechanism for supplying liquid into a compression chamber formed within the housing.

[0018] The screw compressor is characterized in that...

[0019] The liquid supply mechanism has the following structure:

[0020] The device has a recess with an opening on the inner surface of the housing. In a first region on the bottom side of the recess, a longitudinal wall surface along the depth direction of the recess and an outlet for a liquid inlet flow path opening towards the longitudinal wall surface are disposed.

[0021] A bent surface is provided in a second region on the inner surface side of the recess, which is continuous with the first region. The bent surface bends at the boundary with the longitudinal wall and is continuous in the direction away from the outlet of the liquid inlet flow path.

[0022] Invention Effects

[0023] The screw compressor according to the present invention can fully atomize liquid into tiny droplets and supply them to the air compression chamber via a liquid supply mechanism. Other features related to the present invention can be understood from the description and drawings in this specification. Furthermore, issues, configurations, and effects other than those described above will become clear from the following description of embodiments. Attached Figure Description

[0024] Figure 1 This is a diagram showing the configuration of a screw compressor according to the first embodiment of the present invention.

[0025] Figure 2 It is along Figure 1 A cross-sectional view of the screw rotor and liquid supply mechanism around the II-II line.

[0026] Figure 3 This is a diagram showing the configuration of the liquid supply mechanism in the screw compressor of the first embodiment.

[0027] Figure 4 This is a cross-sectional view showing the structure of the liquid supply mechanism of the screw compressor according to the first embodiment.

[0028] Figure 5 This is a diagram illustrating the liquid supply method performed by the liquid supply mechanism of the screw compressor according to the first embodiment.

[0029] Figure 6 From Figure 5 Arrow VI indicates the direction of the liquid supply mechanism of the screw compressor in the first embodiment.

[0030] Figure 7A This is a diagram showing an example of the configuration of a longitudinal wall of a liquid supply mechanism.

[0031] Figure 7B This is a diagram showing an example of the configuration of a longitudinal wall of a liquid supply mechanism.

[0032] Figure 7C This is a diagram showing an example of the configuration of a longitudinal wall of a liquid supply mechanism.

[0033] Figure 8 This is a cross-sectional view showing the structure of the liquid supply mechanism of the screw compressor according to the second embodiment.

[0034] Figure 9 This is a diagram illustrating the liquid supply method performed by the liquid supply mechanism of the screw compressor according to the second embodiment.

[0035] Figure 10 This is a cross-sectional view showing the structure of the liquid supply mechanism of the screw compressor according to the third embodiment.

[0036] Figure 11 This is a cross-sectional view showing the structure of the liquid supply mechanism of the screw compressor according to the fourth embodiment. Detailed Implementation

[0037] Hereinafter, embodiments of the liquid supply mechanism of the screw compressor of the present invention will be described with reference to the accompanying drawings. In the drawings, the same reference numerals are used to label the same elements and repeated descriptions are omitted. It should be noted that the present invention is not limited to the embodiments described below, and includes various modifications. For example, the embodiments described below are detailed descriptions made for the purpose of clearly and easily understanding the present invention, and are not necessarily limited to having all the configurations. Furthermore, a portion of the configuration of one embodiment can be replaced with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. Additionally, it is possible to add / delete / replace other configurations in a portion of the configuration of each embodiment.

[0038] <First Embodiment>

[0039] Figure 1 This is a diagram showing the configuration of the screw compressor according to the first embodiment. Figure 2 It is along Figure 1 A cross-sectional view of the screw rotor and liquid supply mechanism around line II-II. Figure 3 This is a diagram showing the configuration of the liquid supply mechanism in the screw compressor of the first embodiment.

[0040] The screw compressor 100 of this embodiment is as follows: Figure 1 As shown, the device includes a screw rotor 1 and a housing 4 for housing the screw rotor 1. The screw rotor 1 has a male rotor 2 and a female rotor 3 that rotate in mesh with each other and have torsional teeth (blades). The female rotor 3 and the male rotor 2 are collectively referred to as the screw rotor.

[0041] The screw compressor 100 includes an intake-side bearing 5 and an exhaust-side bearing 6 for rotatably supporting the male rotor 2 and female rotor 3, respectively, as well as shaft sealing components 7 such as oil seals and mechanical seals. An intake port 14 is provided on the intake-side end face 28 within the housing 4, and an exhaust port 15 is provided on the exhaust-side end face 29. Here, "intake side" refers to the side where air or other gases are drawn in along the axial direction of the screw rotor 1, and "exhaust side" refers to the side where gases are discharged along the axial direction of the screw rotor 1.

[0042] Typically, the suction side end of the male rotor 2 is connected to the motor 8, which serves as the rotation drive source, via a rotor shaft. A cylindrical male-side hole 9 covering the male rotor 2 and a cylindrical female-side hole 10 covering the female rotor 3 are formed on the inner surface 4a of the housing 4. The male rotor 2 and the female rotor 3 are housed in the housing 4 with gaps of several tens to several hundred micrometers relative to the male-side hole 9 and the female-side hole 10, respectively. There are two intersection lines between the male-side hole 9 and the female-side hole 10; the intersection line on the low-pressure side is defined as the suction-side cust 11, and the intersection line on the high-pressure side is defined as the compression-side cust (compression-side intersection line) 12.

[0043] The male rotor 2, driven by the motor 8, rotates the female rotor 3. The compression chamber 13, formed by the tooth grooves of the male rotor 2 and the female rotor 3 and the male side hole 9 and the female side hole 10 surrounding these tooth grooves, expands and contracts. As a result, gases such as air are drawn in from the intake port 14 and discharged from the discharge port 15 after being compressed to a specified pressure.

[0044] Liquids such as lubricating oil are injected from the outside of the screw compressor 100 into the compression chamber 13, the suction side bearing 5, the discharge side bearing 6, and the shaft seal assembly 7 via the liquid supply port 16, the suction side bearing liquid supply port 17, and the discharge side bearing liquid supply port 18. The exhaust air 60 discharged from the discharge port 15 is separated into gases such as air and liquids such as lubricating oil using a centrifugal oil separator 61. The liquid is then cooled to a suitable temperature by a cooler 62 and reused for supply.

[0045] The screw compressor 100 is provided with a liquid supply mechanism 40 for supplying liquids such as lubricating oil to the compression chamber 13 formed within the housing. The liquid supply mechanism 40 is mounted at the front end of the liquid supply port 16. In this embodiment, for example... Figure 3 As shown, three rotors are installed at predetermined intervals along the axial direction of both the male rotor 2 and the female rotor 3.

[0046] Next, the structure of the liquid supply mechanism will be explained. Figure 4 This is a cross-sectional view showing the structure of the liquid supply mechanism of the screw compressor according to the first embodiment. In this embodiment, the liquid supply mechanism 40 is provided on both the male rotor 2 side and the female rotor 3 side. Since these rotors have the same configuration, in the following description, only the configuration of the liquid supply mechanism 40 provided on the male rotor 2 side will be described, and the configuration of the liquid supply mechanism 40 on the female rotor 3 side will be omitted.

[0047] The liquid supply mechanism 40 has a recess 41 that opens onto the inner surface 4a of the housing. The liquid supply mechanism 40 may also be integrally formed with the housing 4, or, for ease of processing and maintenance, may be designed to be separable from the housing 4. In this embodiment, the recess 41 is formed on a recess body 411 that is separate from the housing 4.

[0048] The recess 41 has a groove shape extending along the tooth grooves of the male rotor 2 and the female rotor 3 (see...). Figure 3 The recess 41 has a first region 42 located on the bottom side in the depth direction and a second region 43 continuous with the first region 42 and located on the inner surface 4a side of the recess 41. A liquid collision space is formed in the first region 42 for colliding the liquid 50 with the longitudinal wall surface 422, and a liquid splitting space is formed in the second region 43 for splitting the liquid film 51 into a drag 52 and a droplet 53.

[0049] In the first region 42 of the recess 41, a recess bottom surface 421 parallel to the inner surface 4a of the housing and a pair of longitudinal wall surfaces 422 and 423 rising from both sides of the recess bottom surface 421 in the groove width direction and extending along the depth direction of the recess 41 are formed. One of the longitudinal wall surfaces 422 and 423 is positioned in front of the male rotor 2 in the rotation direction F, and the other longitudinal wall surface 423 is positioned behind the male rotor 2 in the rotation direction F compared to the first longitudinal wall surface 422. That is, one longitudinal wall surface 422 is positioned facing the rotation direction of the screw rotor 1.

[0050] The liquid supply mechanism 40 has a liquid inlet flow path 44 for introducing liquid from the outside of the housing 4 into the recess 41. An outlet 441 of the liquid inlet flow path 44 is provided on the bottom surface 421 of the recess. The outlet 441 of the liquid inlet flow path 44 is positioned facing an opening to a longitudinal wall surface 422. The liquid inlet flow path 44 is formed toward the longitudinal wall surface 422, that is, it is configured to extend in a direction that gradually approaches the longitudinal wall surface 422 as it moves toward the outlet 441. The liquid inlet flow path 44 is formed at an inclined angle θa relative to the longitudinal wall surface 422, such that liquid ejected from the outlet 441 travels along the depth direction of the recess 41 from the bottom side of the recess 41 toward the opening side of the recess 41 and collides with the longitudinal wall surface 422 at an inclined angle. The inclined angle θa is set to be less than a right angle. The base end of the inlet of the liquid inlet flow path 44 is connected to a common rail or similar liquid container 63. Liquid accumulated in the liquid container 63 is supplied to the liquid supply mechanism 40.

[0051] The second region 43 of the recess 41 has a configuration with a bent surface 431, which bends at the boundary with a longitudinal wall surface 422 and is continuous in the direction away from the outlet 441 of the liquid inlet flow path 44. The bent surface 431 bends at a predetermined angle θb relative to the longitudinal wall surface 422, and an edge 432 is formed at the boundary with the longitudinal wall surface 422. In this embodiment, the bent surface 431 is bent perpendicularly into a stepped shape at the boundary with the longitudinal wall surface 422, becoming a surface discontinuous with the longitudinal wall surface 422. Furthermore, a longitudinal wall surface 433 is provided at the end of the bent surface 431, which bends towards the inner surface 4a of the housing and stands upright.

[0052] Furthermore, an inclined surface 434 is formed in the second region 43 of the recess 41, which bends at the boundary with another longitudinal wall surface 423 and continues in a direction away from one longitudinal wall surface 422. The inclined surface 434 bends relative to the other longitudinal wall surface 423 at a predetermined angle θc. The inclined surface 434 is inclined in such a way that it moves from the inner surface 4a of the housing to the bottom surface 421 of the recess 41 as it moves along the rotation direction of the screw rotor 1. The angle θc of the inclined surface 434 is set such that the gas extruded by the male rotor 2 in the compression chamber 13 and moving along the inner surface 4a of the housing can flow smoothly into the recess 41.

[0053] Next, use Figure 5 and Figure 6 To illustrate the liquid supply method of the liquid supply mechanism 40.

[0054] Figure 5 This diagram illustrates the liquid supply method performed by the liquid supply mechanism of the screw compressor according to the first embodiment. Figure 6 From Figure 5 Arrow VI indicates the direction of the liquid supply mechanism of the screw compressor in the first embodiment.

[0055] Liquid is stored in liquid container 63 under pressure and supplied from liquid container 63 to liquid inlet flow path 44. Liquid 50 supplied to liquid inlet flow path 44 is ejected from outlet 441 into first region 42 of recess 41 and collides with a longitudinal wall surface 422 facing outlet 441 to form a thin liquid film 51 that moves along a longitudinal wall surface 422 in first region 42.

[0056] A thin liquid film 51, moving along a longitudinal wall 422 within the first region 42, enters the second region 43 through an edge 432 formed at the boundary between the longitudinal wall 422 and the bent surface 431. Here, the longitudinal wall 422 and the bent surface 431 bend into a stepped shape at the edge 432, becoming a discontinuous surface.

[0057] Therefore, the liquid film 51 does not move along the bending surface 431 when entering the second region 43, but detaches from the longitudinal wall surface 422 under its own inertial force and is released into the air in the second region 43 of the recess 41. Due to the disturbance caused by the airflow in the air and the instability of the surface tension generated on the surface of the liquid film 51, the liquid film 51 released into the air splits into ligements 52 and / or droplets 53 in the second region 43. Then, in a state of sufficiently small dropletization in the second region 43, it is supplied from the recess 41 into the compression chamber 13. Therefore, the cooling performance of the compressed air in the compression chamber 13 and the sealing performance of the gaps between the parts can be improved.

[0058] In this embodiment, an inclined surface 434 is formed, which bends at the boundary with another longitudinal wall surface 423 and continues in a direction away from one longitudinal wall surface 422. This inclined surface 434 can smoothly guide the air A, which is squeezed out by the male rotor 2 in the compression chamber 13 and moves along the inner surface 4a of the housing, into the second region 43 of the recess 41. That is, the inclined surface 434 forms an air introduction passage for introducing air into the recess 41.

[0059] This increases the disturbance caused by airflow in the air, promoting the splitting of the thin liquid film 51 within the second region 43 of the recess 41. Through these effects, sufficient micro-dropletization is achieved when the liquid is ejected from the liquid supply mechanism 40, thereby improving the cooling performance of the compressed air and the sealing performance of the gaps between parts.

[0060] According to the screw compressor 100 of this embodiment, the total surface area of ​​the droplets is increased by miniaturizing the droplets, thereby cooling the compressed gas and increasing its density, thus improving the compression efficiency. In addition, by miniaturizing the droplets and dispersing them over a wide area of ​​the air compression chamber, the liquid is uniformly attached to the gaps between the screw rotors and the gaps between the screw rotors and the housing, thereby reducing gas leakage through the gaps.

[0061] Furthermore, according to the screw compressor 100 of this embodiment, such as Figure 3 As shown, the liquid supply mechanism 40 is configured such that the major axis of the liquid spray from the liquid supply mechanism 40 is parallel to the ridge line of the screw tooth tips 2a and 3a. The droplets are ejected elliptically from the recess 41 of the liquid supply mechanism 40, thus the major axis of the ellipse is parallel to the ridge line of the screw tooth tip, which can uniformly disperse the droplets into the space, thereby improving the cooling and sealing effects.

[0062] Figure 7A This diagram illustrates an example of the configuration of a longitudinal wall of a liquid supply mechanism, showing the structure of... Figure 5 The shape of the thin liquid film 51 formed by the VII-VII line section.

[0063] In this configuration example, the longitudinal wall surface 422 has a flat planar portion 422A with a flat surface shape. Therefore, when the liquid 50 collides with the planar portion 422A of the longitudinal wall surface 422, it can rapidly diffuse from the collision position along the length direction of the recess 41 in a direction away from each other, forming a thin liquid film 51, which is easy to form into tiny droplets. In addition, the planar portion 422A is easy to process, and the processing time for forming the longitudinal wall surface 422 can be optimized.

[0064] Figure 7B This is a diagram showing another configuration example of a longitudinal wall surface of a liquid supply mechanism, illustrating... Figure 5 The shape of the thin liquid film 51 formed by the VII-VII line section.

[0065] exist Figure 7B In the illustrated configuration, the longitudinal wall surface 422 has a concave curved surface portion 422B that curves concavely in the direction away from the outlet 441 of the liquid inlet flow path 44. The concave curved surface portion 422B is formed along the length direction of the recess 41 and has a concave curved surface shape that curves concavely in a direction orthogonal to the direction of liquid injection. As a result, the force pressing the thin liquid film 51 against the liquid impact surface 33 increases, allowing the liquid film to be thinned from a position closer to the impact location, thus forming a more uniform and thinner liquid film. Consequently, it is possible to further promote the formation of microdroplets.

[0066] Figure 7C This is a diagram showing another configuration example of a longitudinal wall surface of a liquid supply mechanism, illustrating... Figure 5 The shape of the thin liquid film 51 formed by the VII-VII line section.

[0067] exist Figure 7C In the illustrated configuration, the longitudinal wall surface 422 has a convex curved surface 422C that curves convexly in the direction away from the outlet 441 of the liquid inlet flow path 44 and protrudes in a mound-like shape. The convex curved surface 422C is formed along the length direction of the recess 41 and has a convex curved surface shape that curves convexly in a direction orthogonal to the direction of liquid injection. Therefore, when the liquid 50 collides with the longitudinal wall surface 422, the liquid film 51 can be diffused over a wider range. As a result, tiny droplets can be diffused from the liquid supply mechanism 40 over a wider range, improving the cooling and sealing effects of the screw compressor 100.

[0068] <Second Implementation>

[0069] Next, the screw compressor of the second embodiment will be described. Figure 8 This is a cross-sectional view showing the structure of the liquid supply mechanism of the screw compressor according to the second embodiment. Figure 9 This is a diagram illustrating the liquid supply method performed by the liquid supply mechanism of the screw compressor according to the second embodiment.

[0070] This embodiment is characterized in that the second region 43 of the recess 41 has a bent surface 435 inclined relative to the longitudinal wall surface 422. The bent surface 435 has a planar shape that bends at the boundary portion with a longitudinal wall surface 422 and is continuous in a direction away from the outlet 441 of the liquid inlet flow path 44. The bent surface 435 is positioned facing the rotation direction of the screw rotor 1.

[0071] The bent surface 435 is bent at a predetermined angle θb relative to a longitudinal wall surface 422, and an edge 432 is formed at the boundary portion with the longitudinal wall surface 422. In this embodiment, the bent surface 435 is bent into a conical shape at the boundary portion with the longitudinal wall surface 422, and is inclined in a manner that gradually moves away from the outlet 441 as it moves from the boundary portion toward the inner surface 4a of the housing, thus becoming a surface discontinuous with the longitudinal wall surface 422.

[0072] Therefore, the liquid film 51 formed by the collision of liquid 50 with the longitudinal wall surface 422 does not move along the bending surface 431 when entering the second region 43. Instead, it detaches from the longitudinal wall surface 422 under its own inertial force and is released into the air in the second region 43 of the recess 41. Due to the disturbance caused by the airflow in the air and the instability of the surface tension generated on the surface of the liquid film 51, the liquid film 51 released into the air breaks into a trailing strip 52 and droplets 53 in the second region 43. Then, it is supplied from the recess 41 into the compression chamber 13 in a state of sufficiently small droplets in the second region 43. Therefore, the cooling performance of the compressed air in the compression chamber 13 and the sealing performance of the gaps between the parts can be improved.

[0073] The recess 41 forms a conical opening with a bent surface 435 and an inclined surface 434. Furthermore, in this embodiment, the inclination angle θb of the bent surface 435 is smaller than the inclination angle θc of the inclined surface 434 relative to the longitudinal wall surface 423 at the boundary portion with the other longitudinal wall surface 423 (θb < θc). That is, when comparing the inclination angle θb of the bent surface 435 with the inclination angle θc of the inclined surface 434, the inclination angle θc of the inclined surface 434 is larger relative to the depth direction of the recess 41.

[0074] In other words, the inclination angle θc of the inclined surface 434 located upstream of the airflow moving along the inner surface 4a of the housing is greater than the inclination angle θb of the bent surface 435 located downstream of the airflow. Therefore, more gas that is squeezed out by the male rotor 2 in the compression chamber 13 and moves along the inner surface 4a of the housing can actively flow into the recess 41, generating a strong disturbance caused by the airflow.

[0075] <Third Embodiment, Fourth Embodiment>

[0076] Next, the screw compressors of the third and fourth embodiments will be described. Figure 10 , Figure 11 This is a diagram showing the structure of the liquid supply mechanism of the screw compressor according to the third embodiment. Figure 10 The screw compressor shown and Figure 11 The screw compressor shown has the same configuration as the first and second embodiments, except that the inclination angle of the bent surface is different.

[0077] The characteristic of this embodiment is that the inclination angle θa of the longitudinal wall surface 422 is greater than that of the first and second embodiments described above, thereby increasing the angle at which the liquid ejected from the outlet 441 collides with the longitudinal wall surface 422. The inclination angle θa is smaller than the angle perpendicular to the longitudinal wall surface 422 but larger than that of the first and second embodiments.

[0078] The longitudinal wall surface 422 gradually slopes towards the outlet 441 as it approaches the second region 43 from the bottom surface 421 of the recess (in Figure 6 (The slope is such that it slopes more to the right as it goes up). That is, the longitudinal wall surface 422 slopes in an inverted cone shape as it moves from the bottom side of the recess 41 towards the inner surface 4a of the shell along the depth direction of the recess 41 towards the outlet 441 of the liquid inlet flow path 44. As a result, the thrust of the liquid ejected from the outlet 441 colliding with the longitudinal wall surface 423 increases, and the thin liquid film 51 becomes thinner as it approaches the second region 43. As a result, it further promotes the formation of tiny liquid droplets.

[0079] The embodiments of the present invention have been described in detail above, but the present invention is not limited to the foregoing embodiments, and various design changes can be made without departing from the spirit of the invention as set forth in the claims. For example, the foregoing embodiments are detailed descriptions made for the purpose of clearly and easily explaining the present invention, but are not necessarily limited to having all the described configurations. In addition, a part of the configuration of a certain embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can also be added to the configuration of a certain embodiment. Furthermore, other configurations can be added / deleted / replaced for a part of the configuration of each embodiment. Explanation of reference numerals in the attached figures

[0080] 1…Screw rotor, 4…Housing, 4a…Inner surface of housing, 13…Compression chamber, 40…Liquid supply mechanism, 41…Recess, 42…First region (space for liquid collision), 43…Second region (space for liquid splitting), 44…Liquid inlet flow path, 100…Screw compressor, 421…Bottom surface of recess, 422…Longitudinal wall surface, 422B…Concave curved surface, 422C…Convex curved surface, 431, 435…Bending surface, 432…Edge, 441…Outlet, 434…Inclined surface.

Claims

1. A screw compressor comprising a screw rotor and a housing for housing the screw rotor, and a liquid supply mechanism for supplying liquid into a compression chamber formed within the housing, characterized in that... The liquid supply mechanism is constructed as follows: The device has a recess with an opening on the inner surface of the housing. In a first region on the bottom side of the recess, a longitudinal wall surface along the depth direction of the recess and an outlet for a liquid inlet flow path opening towards the longitudinal wall surface are disposed. A bent surface is provided in a second region on the inner surface side of the recess, which is continuous with the first region. The bent surface bends at the boundary with the longitudinal wall and is continuous in the direction away from the outlet of the liquid inlet flow path.

2. The screw compressor according to claim 1, characterized in that, The bent surface is formed in a stepped manner at the boundary with the longitudinal wall surface.

3. The screw compressor according to claim 1, characterized in that, The bent surface bends into a cone shape at the boundary with the longitudinal wall, and tilts in a manner that gradually shifts away from the outlet of the liquid inlet flow path as it moves from the boundary towards the inner surface of the housing.

4. The screw compressor according to claim 1, characterized in that, The liquid inlet flow path is configured at an angle relative to the longitudinal wall surface so that the liquid ejected from the outlet collides at an angle with the longitudinal wall surface from the bottom side of the recess.

5. The screw compressor according to claim 1, characterized in that, In the first region, the longitudinal wall surface is formed parallel to the ridge line of the screw tooth tip of the screw rotor.

6. The screw compressor according to claim 1, characterized in that, The longitudinal wall surface and the bent surface are positioned facing the rotation direction of the screw rotor.

7. The screw compressor according to claim 6, characterized in that, It has an inclined surface, which is positioned in the second region opposite to the bent surface, and is inclined in such a way that it moves from the inner surface of the housing toward the bottom side of the recess as it moves along the rotational direction of the screw rotor.

8. The screw compressor according to claim 7, characterized in that, The tilt angle of the inclined surface relative to the depth direction of the recess is greater than the tilt angle of the bent surface.

9. The screw compressor according to claim 1, characterized in that, The longitudinal wall surface is inclined in an inverted cone shape as it gradually moves toward the outlet of the liquid inlet flow path along the depth direction of the recess from the bottom side of the recess toward the inner surface of the housing.

10. The screw compressor according to claim 1, characterized in that, The longitudinal wall has a concave curved surface that curves in a concave manner toward the outlet of the liquid inlet flow path.

11. The screw compressor according to claim 1, characterized in that, The longitudinal wall surface has a convex curved surface that curves in a convex shape toward the outlet of the liquid inlet flow path.

12. The screw compressor according to claim 1, characterized in that, The liquid supply mechanism is separate from the housing.

Images