JP2019085969A - Liquid-cooled type screw compressor - Google Patents

Abstract

To improve heat exchange performance and seal performance by preventing uneven distribution of liquid in a liquid-cooled type screw compressor.SOLUTION: An liquid-cooled type screw compressor 1 includes: a screw rotor 40 constituted by a male rotor 50, and a female rotor 60 meshed with the male rotor 50; a rotor casing 10 for storing the screw rotor 40; and a plurality of oil supply ports 13 provided in the rotor casing 10 so as to supply oil into at least two tooth groove spaces of the screw rotor 40.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a liquid-cooled screw compressor.

  An oil-cooled screw compressor, which is a type of liquid-cooled screw compressor, in which the heat exchange between gas and oil during compression is promoted by devising the arrangement of injection nozzles (fueling ports) For example, it is disclosed in Patent Document 1. In the oil-cooled screw compressor of Patent Document 1, the injection direction from the injection nozzle into the compression chamber (rotor chamber) is opposite to the rotation direction of the screw rotor. As a result, the time for the oil to travel through the gas in the compression chamber is secured for a long time, and the heat exchange between the oil and the gas is promoted.

JP-A-9-151870

  Since the oil-cooled screw compressor rotates the screw rotor at high speed to compress the gas, even if the injection direction is changed as described above, the time for oil to contact the air before contacting the rotor casing and screw rotor is long It is considered to increase only slightly. Therefore, the heat exchange performance can be expected to be only slightly improved, and there is room for improvement for further improvement of the heat exchange performance. Furthermore, no special consideration has been made on the improvement of the sealing performance with oil between the male rotor, the female rotor and the rotor casing. Particularly, in the oil-cooled screw compressor of Patent Document 1, although the oil is supplied to the low pressure portion, the oil may run short at the high pressure portion. In addition, if the amount of oil conveyed to the high pressure part is increased by increasing the amount of oil supply in the low pressure part, the oil will be excessively supplied in the low pressure part, and power loss due to excessive oil agitation will occur.

  An object of the present invention is to improve heat exchange performance and seal performance by preventing uneven distribution of liquid (oil) in a liquid-cooled screw compressor, particularly an oil-cooled screw compressor.

  According to the present invention, a screw rotor comprising a male rotor, a female rotor meshing with the male rotor, a rotor casing accommodating the screw rotor, and the rotor casing are supplied into at least two groove spaces of the screw rotor. An oil-cooled screw compressor is provided, comprising a plurality of fluid inlets and a plurality of fluid outlets.

  According to this configuration, in the rotor casing, since the liquid supply port is arranged to supply the liquid into at least two groove spaces of the screw rotor, it is possible to prevent uneven distribution of the liquid. Here, the tooth space refers to a communication space defined by the rotor casing, the teeth of the male rotor and the teeth of the female rotor. By preventing the uneven distribution of the liquid, heat exchange between the liquid and the compressed gas can be promoted, the heat exchange performance can be improved, and the seal performance by the liquid between the male rotor, the female rotor and the rotor casing can also be improved. Therefore, since the compression efficiency is improved, the energy saving performance can be improved.

  The system may further include a liquid supply amount adjusting mechanism that reduces the amount of liquid supplied from the liquid supply port as it goes from the low pressure side to the high pressure side.

  According to this configuration, uneven distribution of the liquid can be further prevented. Since the volume of gas in the space of the tooth space decreases as it is compressed, the required amount of liquid supply decreases as it goes from the low pressure section to the high pressure section. Therefore, the necessary amount of liquid can be supplied to the appropriate place by reducing the amount of supplied liquid as going from the low pressure part to the high pressure part by the liquid supply amount adjusting mechanism. Thereby, since excessive supply of liquid to the low pressure part can be prevented, the power saving performance can be improved by reducing the power loss due to the stirring of the excessive liquid.

  The plurality of liquid supply ports may be further provided with a linear liquid supply pipe that is disposed on a straight line and connects the liquid feed ports disposed on a straight line.

  According to this configuration, since the liquid supply pipe is linear, it is possible to prevent the shape of the liquid supply pipe from being complicated, and to reduce the number of steps for processing the liquid supply pipe. In addition, it is not necessary for all the liquid supply ports to be provided on a straight line, and in addition to the plurality of liquid supply ports disposed on a straight line, a liquid supply port disposed outside the straight line may exist.

  At least two liquid supply ports among the plurality of liquid supply ports are provided on one side of the male rotor or the female rotor, and the adjacent liquid supply provided on the one side in the extending direction of the screw rotor The distance between the furthest points of the mouths may be smaller than the width of the groove on the one side of the male rotor or the female rotor.

  According to this configuration, at least two liquid supply ports can be disposed in one tooth groove. Therefore, the lack of fluid in the tooth space can be suppressed. Therefore, the cooling performance and the sealing performance by a sufficient amount of liquid can be improved, and the compression efficiency can be improved.

  At least two liquid supply ports among the plurality of liquid supply ports are provided on one side of the male rotor or the female rotor, and the adjacent liquid supply provided on the one side in the extending direction of the screw rotor The distance between the nearest points of the mouth is larger than the width of the groove on the one side, or the distance between the most distant points of adjacent liquid supply ports provided on the one side is greater than the width of the groove on the one side It may be small.

  According to this configuration, noise can be reduced. Temporarily, the distance between the nearest points of adjacent liquid supply ports is smaller than the width of the tooth groove on the side where the liquid supply ports are provided in the male rotor or female rotor, and the distance between the farthest points between adjacent liquid supply ports is If the width of the groove between the male rotor and the female rotor on the side where the liquid supply port is provided is larger, the tip of the tooth will be located near the liquid supply port at the same time. The pressure at the supply port rapidly increases due to the centrifugal force when the tip of the tooth passes, so if the pressure increases rapidly at the two adjacent supply ports at the same time, the pressure in the supply pipe rapidly increases. A sudden rise in pressure in the fluid supply pipe causes pulsation, which causes noise. Therefore, noise can be reduced by providing the liquid supply port while avoiding the above case.

  The rotor casing has a suction port at a position corresponding to the end of the screw rotor in the extending direction of the screw rotor, and the position of the liquid feed port closest to the suction port among the plurality of liquid feed ports. The gear slot may be separated from the suction port by a width equal to or greater than a tooth groove width on the side of the male rotor or the female rotor provided with the liquid supply port closest to the suction port.

  According to this configuration, even if the screw rotor rotates, the fluid supply port closest to the suction port (on the lowest pressure side) and the suction port are not fluidly connected. Therefore, it is possible to prevent the liquid from leaking into the suction port, generating suction heating, and lowering the volumetric efficiency.

  The rotor casing has a discharge port at a position corresponding to an end of the screw rotor in a direction in which the screw rotor extends, and a position of the liquid supply port closest to the discharge port among the plurality of liquid supply ports. In the male rotor or the female rotor, the discharge slot may be separated from the discharge port by a width of a tooth groove width on the side provided with the liquid supply port closest to the discharge port.

  According to this configuration, even if the screw rotor rotates, the liquid supply port closest to the discharge port (on the highest pressure side) and the discharge port are not fluidly connected. As a result, it is possible to prevent the liquid from flowing backward from the discharge port into the liquid supply port and to reduce the volumetric efficiency, and to prevent the power loss due to the recompression.

  According to the present invention, in the liquid-cooled screw compressor, since liquid is supplied into at least two groove spaces of the screw rotor, uneven distribution of liquid can be prevented, and heat exchange performance and sealing performance are improved. It can be done.

A partial schematic configuration diagram of an oil-cooled screw compressor according to a first embodiment of the present invention Typical cross-sectional view of the rotor casing along the line II-II in FIG. 1 Typical cross-sectional view showing the position of the filler opening in the rotor casing Typical cross-sectional view showing the position of the filler opening in the rotor casing Sectional drawing which shows arrangement | positioning of the rotor casing of oil-cooled type screw compressor of a 1st modification. Sectional drawing which shows arrangement | positioning of the rotor casing of oil-cooled type screw compressor of the 2nd modification Typical cross-sectional view showing the position of the oil supply port in the rotor casing of the oil-cooled screw compressor according to the second embodiment Typical cross-sectional view showing the position of the oil supply port in the rotor casing of the oil-cooled screw compressor according to the third embodiment

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In addition, the oil-cooling-type screw compressor which uses oil for the liquid supplied in a rotor casing is shown as what concerns on embodiment of this invention. Therefore, hereinafter, "oil" may be read as "liquid".

First Embodiment
FIG. 1 is a partial schematic configuration view of an oil-cooled screw compressor 1 according to a first embodiment of the present invention. Hereinafter, the oil-cooled screw compressor 1 is also referred to simply as the compressor 1. FIG. 1 shows a portion of the compressor 1 that relates particularly to a compression mechanism. The compressor 1 sucks in air from the outside, compresses it inside, and discharges it. The air discharged from the compressor 1 is supplied to the supply destination through piping (not shown).

  The compressor 1 includes a rotor casing 10 and bearing casings 20 and 21. In the present embodiment, the rotor casing 10 and the bearing casings 20 and 21 are integrated. The rotor casing 10 is disposed between the two bearing casings 20, 21. The rotor casing 10 internally defines a rotor chamber 30, and the two bearing casings 20 and 21 respectively define bearing chambers 33 and 34 therein. The rotor chamber 30 and the bearing chamber 33 are partitioned via the partition wall 11, and the rotor chamber 30 and the bearing chamber 34 are partitioned via the partition wall 12. The partition walls 11 and 12 are both parts of the rotor casing 10.

  In the rotor casing 10, a male rotor 50 and a female rotor 60 that meshes with the male rotor 50 and has more teeth than the male rotor 50 are disposed. That is, the screw rotor 40 is configured by the male rotor 50 and the female rotor 60. Although details are not illustrated, in the present embodiment, for example, the male rotor 50 has a four-tooth shape, and the female rotor 60 has a six-tooth shape.

  FIG. 2 is a schematic cross-sectional view of the rotor casing 10 taken along line II-II of FIG. The rotor casing 10 defines a male rotor chamber 31 housing the male rotor 50 and a female rotor chamber 32 housing the female rotor 60. The rotor chamber 30 is a space in which the male rotor chamber 31 and the female rotor chamber 32 are combined. The rotor casing 10 has a shape in which two cylinders are connected on the side, in other words, the male rotor chamber 31 and the female rotor chamber 32 are both cylindrical spaces and are in communication with each other.

  FIG. 2 is also a cross-sectional view of the female rotor 60 (see FIG. 1) as viewed from the rotational axis direction. In the present embodiment, the rotation axis of the female rotor 60 and the rotation axis of the male rotor 50 extend horizontally in parallel with each other, and the male rotor chamber 31 and the female rotor chamber 32 extend in the same direction. In the cross-sectional view of FIG. 2, the male rotor chamber 31 and the female rotor chamber 32 are connected by the suction side cusp point 14a and the discharge side cusp point 14b. The lowest point P3 of the male rotor chamber 31 is located below the discharge-side cusp point 14b connecting the male rotor chamber 31 and the female rotor chamber 32.

  As shown in FIG. 1, from one end of the male rotor 50, a shaft member 51 serving as a rotation axis of the male rotor 50 extends. The shaft member 51 penetrates the partition wall 11 and extends from the male rotor chamber 31 to the bearing chamber 33, and is rotatably supported by the bearing 54 in the bearing chamber 33. Further, also from one end of the female rotor 60, a shaft member 61 serving as a rotation shaft of the female rotor 60 extends. The shaft member 61 penetrates the partition wall 11 and extends from the female rotor chamber 32 to the bearing chamber 33, and is rotatably supported by the bearing 63 in the bearing chamber 33.

  From the other end of the male rotor 50, a shaft member 52 serving as a rotation shaft of the male rotor 50 extends. The shaft member 52 extends from the male rotor chamber 31 to the bearing chamber 34 through the partition wall 12 and is rotatably supported by the bearing 54 in the bearing chamber 34. Further, also from the other end of the female rotor 60, a shaft member 62 serving as a rotation shaft of the female rotor 60 extends. The shaft member 62 extends from the female rotor chamber 32 to the bearing chamber 34 through the partition wall 12 and is rotatably supported by the bearing 64 in the bearing chamber 34. In particular, the shaft member 52 of the male rotor 50 extends to a motor (not shown) and is mechanically connected to the motor. Accordingly, the male rotor 50 is rotationally driven by this motor, rotational power is transmitted from the male rotor 50 to the female rotor 60, and the male rotor 50 and the female rotor 60 mesh with each other and rotate to compress air. In FIG. 1, the right side is the suction side, and the left side is the discharge side. Therefore, when the male rotor 50 and the female rotor 60 rotate, in the rotor chamber 30, air is sucked from the bearing chamber 34 side, and the air is discharged to the bearing chamber 33 side.

  As shown in FIG. 2, the rotor casing 10 is provided with a filler port 13 on the side of the female rotor chamber 32. Three virtual line segments S1 to S3 are defined in order to define the detailed position of the fuel filler 13. A first virtual line segment S1 connecting the rotation center point P1 of the female rotor 60 and the discharge side cusp point 14b is defined. A second virtual line segment S2 is defined by rotating the first virtual line segment S1 around the rotation center point P1 of the female rotor 60 by a first predetermined angle θ1 in a direction away from the male rotor 50. Here, the first predetermined angle θ1 is an angle that can prevent the concentration of oil at the meshing position (which substantially matches the discharge-side cusp point 14b), and the shapes of the male rotor 50 and the female rotor 60, the rotor casing 10 It depends on the shape of the and the type of oil. Then, a first center line L1 including the rotation center point P2 of the male rotor 50 and the rotation center point P2 of the female rotor 60 is defined. The first center line L1 is a horizontal line. Further, a second center line L2 that is orthogonal to the first center line L1 and passes through the rotation center point P1 of the female rotor 60 is defined. Then, a third imaginary line segment S3 rotated about the rotation center point P1 of the female rotor 60 from the second center line L2 by the second predetermined angle θ2 in a direction away from the discharge-side cusp point 14b is defined. Here, the second predetermined angle θ2 is an angle that can prevent oil shortage at the meshing position, and depends on the shapes of the male rotor 50 and the female rotor 60, the shape of the rotor casing 10, the type of oil, etc. It becomes settled.

  The filler opening 13 is provided in the range excluding the range from the first virtual line segment S1 to the second virtual line segment S2, and more specifically, provided in the range from the second virtual line segment S2 to the third virtual line segment S3. Being preferred. More specifically, it is preferable that even part of the fuel filler 13 be provided in the range from the second virtual line segment S2 to the third virtual line segment S3. Here, it is preferable that the first predetermined angle θ1 be, for example, about 30 degrees or more. Further, the second predetermined angle θ2 is, for example, about 1⁄4 or less of the angle of one tooth of the female rotor 60, and in the present embodiment, since the six-tooth female rotor 60 is employed, 15 degrees It is preferable that it is below a grade. In the present embodiment, the fuel supply port 13 is provided in the range from the second virtual line segment S2 to the third virtual line segment S3, specifically, provided on the second center line L2.

  By providing the oil supply port 13 in the above range, it is possible to prevent the oil from being concentrated at the meshing position of the male rotor 50 and the female rotor 60. In general, in the oil-cooled screw compressor 1, the rotation of the male rotor 50 and the female rotor 60 tends to concentrate the oil at the meshing position between the male rotor 50 and the female rotor 60. If the fuel supply port 13 is provided in the range from the first virtual line segment S1 to the second virtual line segment S2, the oil is engaged near the meshing position between the male rotor 50 and the female rotor 60. By concentrating on the above, there is a possibility that the loss of stirring of the oil will be excessive and the compression efficiency will deteriorate. However, in the configuration of the present embodiment, since the fuel supply port 13 is provided at a position distant from the meshing position by a certain degree (a range excluding the range from the first virtual line segment S1 to the second virtual line segment S2) Concentration of oil can be prevented, and deterioration of compression efficiency can be prevented.

  Further, by providing the fuel supply port 13 in the range from the second virtual line segment S2 to the third virtual line segment S3, the sealability at the meshing position between the male rotor 50 and the female rotor 60 can be secured. If the fuel supply port 13 is disposed at a position far away from the meshing position, there is a possibility that oil can not be sufficiently supplied to the meshing position between the male rotor 50 and the female rotor 60. In that case, air may leak at the meshing position of the male rotor 50 and the female rotor 60, and the compression efficiency may be deteriorated. However, in the configuration of the present embodiment, the fuel supply port 13 is provided at a position close to a certain degree from the meshing position (a range from the second virtual line segment S2 to the third virtual line segment S3). It can supply oil. Therefore, the sealability at the meshing position can be secured, and the deterioration of the compression efficiency can be prevented.

  3 and 4 are schematic cross-sectional views showing the position and the size of the fuel filler 13 in the rotor casing 10. As shown in FIG. In the present embodiment, a plurality of (three in FIGS. 3 and 4) fuel ports 13a, 13b and 13c are linearly arranged in a state in which they are connected by a linear fuel piping 15. The oil supply pipe 15 extends in parallel with the rotation axis of the female rotor 60.

  It is preferable that the oil supply ports 13 a to 13 c be arranged to supply oil into at least two tooth space spaces of the screw rotor 40. The groove space is a communication space defined by the rotor casing 10, the teeth of the male rotor 50 and the teeth of the female rotor 60. For example, one tooth space is indicated by a hatched portion in FIG. In the present embodiment, the distance d1 between the fuel nozzle 13a and the fuel nozzle 13c (the distance d1 between the fuel nozzle 13a and the fuel nozzle 13c) is greater than the groove width D1 of the female rotor 60 (d1> D1). As a result, the filler port 13a and the filler port 13c are located in different tooth space spaces, so that it is possible to supply oil to at least two tooth space spaces.

  The distance d2 between the farthest points between the adjacent fuel inlets 13a and 13b (the distance d2 between the fuel inlet 13a and the fuel inlet 13b) is smaller than the groove width D1 of the female rotor 60 (d2 <D1 ). Similarly, the distance d3 between the farthest points between the adjacent fuel inlet 13b and the fuel inlet 13c (the distance d3 between the fuel inlet 13b and the farthest part of the fuel inlet 13c) is smaller than the groove width D1 of the female rotor 60 ( d3 <D1). Due to these dimensional relationships, when the female rotor 60 rotates and its tip moves, at least two filler openings 13a, 13b or filler openings 13b, 13c are arranged in one tooth groove. Further, as described later, the tooth tips of the female rotor 60 are not simultaneously positioned at the adjacent two fuel inlets 13a and 13b or the adjacent two fuel outlets 13b and 13c, as described later. It is possible to prevent the pressure in the fuel supply pipe 15 from rising rapidly.

  The radiuses r1 to r3 of the three fueling ports 13a to 13c are set so as to decrease the amount of fueling from the low pressure side to the high pressure side. Specifically, the radius r1 is the largest, the radius r2 is the second largest, and the radius r3 is the smallest. In the present embodiment, for example, the radius r1 is about 1.5 times the radius r2, and the radius r2 is about 1.5 times the radius r3. In the present embodiment, the three fueling ports 13a to 13c constitute a fueling amount adjusting mechanism.

  As shown in FIGS. 3 and 4, the rotor casing 10 has a suction port 10 a on one end side (upper side in FIG. 3, right side in FIG. 4) of the screw rotor 40 in the rotational axis direction. The suction port 10 a is provided at the top of the rotor casing 10 and extends around the male rotor 50 and the female rotor 60. Further, the position of the filler port 13a closest to the suction port 10a among the plurality of filler ports 13a to 13c in the rotational axis direction is separated from the suction port 10a of the tooth groove width D1 or more of the female rotor 60. That is, the distance Δ1 from the fuel supply port 13a to the suction port 10a is equal to or greater than the tooth groove width D1 of the female rotor 60 (Δ1 ≧ D1).

  Further, the rotor casing 10 has a discharge port 10 b on the other end side (lower side in FIG. 3, left side in FIG. 4) in the rotational axis direction. The discharge port 10 b is provided at the lower part of the rotor casing 10. The position of the fuel supply port 13c closest to the discharge port 10b among the plurality of fuel supply ports 13a to 13c in the rotational axis direction is separated from the discharge port 10b by the tooth groove width D1 or more of the female rotor 60. That is, the distance Δ2 from the fuel inlet 13c to the outlet 10b is equal to or greater than the tooth groove width D1 of the female rotor 60 (Δ2ΔD1).

  Below, the effect of the compressor 1 of this embodiment is demonstrated.

  According to the present embodiment, in the rotor casing 10, the oil supply port 13 is disposed so as to supply oil into at least two tooth space spaces of the screw rotor 40, so that uneven distribution of oil can be prevented. By preventing uneven distribution of oil, heat exchange between oil and compressed gas can be promoted, heat exchange performance can be improved, and sealing performance with oil between male rotor 50, female rotor 60 and rotor casing 10 can also be improved. . Therefore, since the compression efficiency is improved, the energy saving performance can be improved.

  Moreover, according to the present embodiment, uneven distribution of oil in the rotor casing 10 can be further prevented. Since the volume of gas in the tooth space decreases as it is compressed, the amount of oil required decreases as it goes from the low pressure section to the high pressure section. Therefore, the required amount of oil can be supplied to the appropriate place by gradually reducing the size of the filler openings 13a to 13c and reducing the amount of oil supply from the low pressure portion to the high pressure portion. Thereby, since excessive oil supply to the low pressure portion can be prevented, the power saving performance can be improved by reducing the power loss due to the excessive oil agitation.

  Further, according to the present embodiment, since the oil supply pipe 15 is linear, it is possible to prevent the shape of the oil supply pipe 15 from being complicated and to reduce the number of steps for processing the oil supply pipe 15. In addition, it is not necessary for all of the filler openings 13 to be provided on a straight line, and in addition to the plurality of filler openings 13 arranged on a straight line, the filler openings 13 arranged outside the straight line may be present.

  Further, according to the present embodiment, since the distances d2, d3 between the farthest points of the adjacent filler openings 13 are defined as described above, at least two filler openings 13 can be arranged in one tooth groove. Therefore, the oil shortage in the tooth space can be suppressed. Therefore, the cooling performance and the sealing performance by a sufficient amount of oil can be improved, and the compression efficiency can be improved.

  Moreover, according to the present embodiment, noise can be reduced. This will be described with reference to FIG. Temporarily, distance d4 and d5 (distance of the nearest part of the adjacent fuel filler openings) of the nearest adjacent fuel filler openings 13 is smaller than tooth slot width D1 of female rotor 60, and distance d2 between the farthest points If d3 is larger than the tooth groove width D1 (d4, d5 <D1 <d2, d3), the tooth tips of the female rotor 60 are simultaneously positioned at the adjacent filler ports 13a, 13b or 13b, 13c. The pressure at the filler opening 13 rapidly increases due to the centrifugal force when the tip of the tooth passes, so if the pressure increases rapidly simultaneously at the two adjacent filler openings, the pressure in the supply piping 15 rapidly increases. A sudden rise in pressure in the oil supply pipe 15 causes pulsation, which causes noise. Therefore, noise can be reduced by providing the filler port avoiding the above case.

  According to the present embodiment, even if the screw rotor 40 rotates, the tooth space where the fuel inlet 13a closest (closest to the low pressure side) to the suction port 10a is opened is the tooth tip of the suction port 10a and the screw rotor 40 Are defined. Therefore, the fuel supply port 13a and the suction port 10a do not communicate directly. That is, according to the present embodiment, even if the screw rotor 40 rotates, the fuel inlet 13a closest to the suction port 10a (on the lowest pressure side) and the suction port 10a are not fluidly connected. Therefore, it is possible to prevent oil from leaking into the suction port, generating suction heating, and lowering the volumetric efficiency.

  Further, according to the present embodiment, even if the screw rotor 40 rotates, the tooth space where the fuel supply port 13c closest (on the highest pressure side) to the discharge port 10b opens is the tooth tip of the discharge port 10b and the screw rotor 40 Are defined. Therefore, the fuel supply port 13c and the discharge port 10b do not communicate directly. That is, according to the present embodiment, even if the screw rotor 40 rotates, the fuel supply port 13c closest to the discharge port 10b (on the highest pressure side) and the discharge port 10b are not fluidly connected. Therefore, it is possible to prevent the oil from flowing backward from the discharge port into the filler port and to reduce the volumetric efficiency, and to prevent the power loss due to the recompression.

(First modification)
FIG. 5 is a cross-sectional view of the rotor casing 10 of the compressor 1 of the first modified example, and is a view corresponding to FIG. In the compressor 1 of the present modified example, the rotor casing 10 is disposed in a state where the first center line L1 is inclined from the horizontal line HL.

  In this modification, the rotation axis CL1 of the female rotor 60 and the rotation axis CL2 of the male rotor 50 are not disposed in the horizontal plane, and the rotation axis CL1 of the female rotor 60 is lower than the rotation axis CL2 of the male rotor 50. Is located in Specifically, the first center line L1 is, for example, about 30 degrees from the horizontal line HL. Therefore, the female rotor chamber 32 is disposed below the male rotor chamber 31.

  Also in the present embodiment, the lowermost point P3 of the male rotor chamber 31 is positioned below the discharge-side cusp point 14b connecting the male rotor chamber 31 and the female rotor chamber 32, as described above.

(2nd modification)
FIG. 6 is a cross-sectional view of the rotor casing 10 of the compressor 1 of the second modified example, corresponding to FIG. In the compressor 1 of the present modification, the rotor casing 10 is disposed in a state where the first center line L1 is vertical.

  In this modification, the rotation axis CL1 of the female rotor 60 and the rotation axis CL2 of the male rotor 50 are not disposed in the horizontal plane, and the rotation axis CL2 of the male rotor 50 is directly below the rotation axis CL1 of the female rotor 60. It is arranged. Therefore, the entire male rotor chamber 31 is disposed below the entire female rotor chamber 32.

  Also in this modification, the lowermost point P3 of the male rotor chamber 31 is located below the discharge-side cusp point 14b connecting the male rotor chamber 31 and the female rotor chamber 32, as in the first modification. .

Second Embodiment
FIG. 7 is a cross-sectional view of the rotor casing 10 of the compressor 1 according to the second embodiment, which corresponds to FIG. 4 of the first embodiment. The compressor 1 of the present embodiment is the same as the configuration of the compressor 1 of the first embodiment except for the configuration related to the fuel filler 13. Therefore, the same parts as those of the configuration shown in the first embodiment are given the same reference numerals and the description thereof is omitted.

  In the present embodiment, unlike the first embodiment, the diameters of the three filler ports 13a to 13c are the same. Flow control valves 13A to 13C are attached to the respective fueling ports 13a to 13c. The flow rate adjusting valves 13A to 13C are set to reduce the amount of fuel supplied from the fueling ports 13a to 13c from the low pressure side (right side in FIG. 7) to the high pressure side (left side in FIG. 7). Specifically, the flow control valve 13A has the largest allowable flow rate, the flow control valve 13B has the second largest allowable flow rate, and the flow control valve 13C has the smallest allowable flow rate. In the present embodiment, the flow rate adjustment valves 13A to 13C constitute a refueling amount adjustment mechanism.

Third Embodiment
FIG. 8 is a cross-sectional view of the rotor casing 10 of the compressor 1 according to the third embodiment, which corresponds to FIG. 4 of the first embodiment. The compressor 1 of the present embodiment is the same as the configuration of the compressor 1 of the first embodiment except for the configuration related to the fuel filler 13. Therefore, the same parts as those of the configuration shown in the first embodiment are given the same reference numerals and the description thereof is omitted.

  In the present embodiment, unlike the first embodiment, the diameters of the three filler ports 13a to 13c are the same. Three refueling pipes 15a-15c are connected to the refueling ports 13a-13c, respectively. The amount of fuel supplied from each of the fueling ports 13a to 13c is set to decrease as it goes from the low pressure side (left side in FIG. 8) to the high pressure side (right side in FIG. 8). Specifically, the thicknesses of the fueling pipes 15a to 15c are different from each other, the fueling pipe 15a is the thickest, the fueling pipe 15b is next thick, and the fueling pipe 15c is the thinnest. In the present embodiment, the refueling pipes 15a to 15c constitute a refueling amount adjustment mechanism.

  As mentioned above, although each concrete embodiment of the present invention was described, the present invention is not limited to the above-mentioned form, and can be variously changed and carried out within the scope of the present invention.

  In the said embodiment, although all the filler ports 13 were arrange | positioned on the straight line, arrangement | positioning of the filler port 13 is not limited to this. For example, some of the fuel filler openings 13 may be disposed on a straight line, and the fuel filler openings 13 may not be disposed on a straight line. Further, the number and the size of the fuel filler 13 are not particularly limited.

  Further, in each of the above embodiments, the arrangement configuration of the fuel supply port 13 provided on the female rotor 60 side can be similarly applied to the male rotor 50 side, and vice versa. That is, the arrangement configuration of the fuel filler 13 of each of the above-described embodiments can be adopted for either one or both of the male rotor 50 and the female rotor 60 without distinction between the male rotor 50 and the female rotor 60.

  As described above, according to the embodiment of the present invention, the oil-cooled compressor using oil for the liquid supplied into the rotor casing has been shown. However, the present invention is applicable to liquid-cooled compressors other than oil-cooled compressors. For example, the present invention can also be applied to a water jet compressor using water as the liquid supplied into the rotor casing.

1 Compressor (oil-cooled screw compressor)
DESCRIPTION OF SYMBOLS 10 Rotor casing 10a Suction port 10b Discharge port 11, 12 Partition wall 13 Refueling port 13a-13c Refueling port (Refueling amount adjustment mechanism)
13A to 13C Flow adjustment valve (lubrication amount adjustment mechanism)
14 Cusp point 14a Suction side cusp point 14b Discharge side cusp point 15 Refueling piping 15a, 15b, 15c Refueling piping (refueling amount adjustment mechanism)
20, 21 bearing casing 30 rotor chamber 31 male rotor chamber 32 female rotor chamber 33, 34 bearing chamber 40 screw rotor 50 male rotor 51, 52 shaft member 53, 54 bearing 60 female rotor 61, 62 shaft member 63, 64 bearing

Claims (7)

A screw rotor comprising a male rotor and a female rotor meshing with the male rotor;
A rotor casing accommodating the screw rotor;
A liquid-cooled screw compressor, comprising: a plurality of liquid supply ports arranged to supply liquid in at least two groove spaces of the screw rotor in the rotor casing.   The liquid cooling screw compressor according to claim 1, further comprising a liquid supply amount adjusting mechanism that reduces the amount of liquid supplied from the liquid supply port as it goes from a low pressure side to a high pressure side. The plurality of liquid supply ports are disposed on a straight line,
The liquid-cooled screw compressor according to claim 2, further comprising a linear liquid supply pipe connecting the liquid supply ports disposed on a straight line. At least two of the plurality of liquid supply ports are provided on one side of the male rotor or the female rotor.
In the extending direction of the screw rotor, the distance between the farthest points of the adjacent liquid supply ports provided on the one side is smaller than the tooth groove width on the one side of the male rotor or the female rotor. The liquid-cooling-type screw compressor of any one of Claims 1-3.   At least two liquid supply ports among the plurality of liquid supply ports are provided on one side of the male rotor or the female rotor, and the adjacent liquid supply provided on the one side in the extending direction of the screw rotor The distance between the nearest points of the mouth is larger than the width of the groove on the one side, or the distance between the most distant points of adjacent liquid supply ports provided on the one side is greater than the width of the groove on the one side The liquid cooled screw compressor according to any one of claims 1 to 4, which is small. The rotor casing has a suction port at a position corresponding to an end of the screw rotor in a direction in which the screw rotor extends.
Among the plurality of liquid supply ports, the position of the liquid supply port closest to the suction port is the tooth groove width on the side where the liquid supply port closest to the suction port is provided among the male rotor or the female rotor The liquid-cooled screw compressor according to any one of claims 1 to 5, which is separated from the suction port as described above. The rotor casing has a discharge port at a position corresponding to an end of the screw rotor in a direction in which the screw rotor extends.
Among the plurality of liquid supply ports, the position of the liquid supply port closest to the discharge port is the tooth groove width on the side on which the liquid supply port closest to the discharge port is provided among the male rotor or the female rotor The liquid-cooled screw compressor according to any one of claims 1 to 6, which is separated from the discharge port as described above.

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