US20220049700A1 - Screw Compressor - Google Patents
Screw Compressor Download PDFInfo
- Publication number
- US20220049700A1 US20220049700A1 US17/298,720 US201917298720A US2022049700A1 US 20220049700 A1 US20220049700 A1 US 20220049700A1 US 201917298720 A US201917298720 A US 201917298720A US 2022049700 A1 US2022049700 A1 US 2022049700A1
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- United States
- Prior art keywords
- rotor
- flow passage
- female
- male
- lobed portion
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 230000004048 modification Effects 0.000 description 6
- 238000012986 modification Methods 0.000 description 6
- 239000007788 liquid Substances 0.000 description 5
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- 230000006835 compression Effects 0.000 description 2
- 238000007906 compression Methods 0.000 description 2
- 238000007599 discharging Methods 0.000 description 2
- 238000001816 cooling Methods 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 230000000153 supplemental effect Effects 0.000 description 1
Images
Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C18/00—Rotary-piston pumps specially adapted for elastic fluids
- F04C18/08—Rotary-piston pumps specially adapted for elastic fluids of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing
- F04C18/12—Rotary-piston pumps specially adapted for elastic fluids of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of other than internal-axis type
- F04C18/14—Rotary-piston pumps specially adapted for elastic fluids of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of other than internal-axis type with toothed rotary pistons
- F04C18/16—Rotary-piston pumps specially adapted for elastic fluids of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of other than internal-axis type with toothed rotary pistons with helical teeth, e.g. chevron-shaped, screw type
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C29/00—Component parts, details or accessories of pumps or pumping installations, not provided for in groups F04C18/00 - F04C28/00
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C29/00—Component parts, details or accessories of pumps or pumping installations, not provided for in groups F04C18/00 - F04C28/00
- F04C29/12—Arrangements for admission or discharge of the working fluid, e.g. constructional features of the inlet or outlet
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C2240/00—Components
- F04C2240/20—Rotors
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C2240/00—Components
- F04C2240/30—Casings or housings
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C2250/00—Geometry
- F04C2250/10—Geometry of the inlet or outlet
- F04C2250/101—Geometry of the inlet or outlet of the inlet
Definitions
- the present invention relates to a screw compressor including a suction port positioned on the outer side in a rotor radial direction and a suction flow passage that communicates in a rotor axial direction with a working chamber.
- the screw compressor described in Patent Document 1 includes a male rotor having a lobed portion, a female rotor having a lobed portion that engages with the lobed portion of the male rotor, and a casing that accommodates the male rotor and the female rotor therein.
- the casing has a bore that accommodates the lobed portion of the male rotor and the lobed portion of the female rotor therein such that working chambers on the male rotor side and working chambers on the female rotor side are formed in lobe grooves of the lobed portions. Further, the casing has a suction port located on the outer side in a rotor radial direction with respect to the lobed portion of the male rotor and the lobed portion of the female rotor, and a suction flow passage formed so as to connect the suction port to the working chambers that are in a suction stroke.
- the casing further has a discharge port located on the outer side in the rotor radial direction from the lobed portion of the male rotor and the lobed portion of the female rotor, and a discharge flow passage formed so as to connect the discharge port to the working chambers that are in a discharge stroke.
- the working chamber is changed in volume while moving from one side to the other side in the rotor axial direction. Consequently, the working chamber sequentially performs a suction stroke for sucking gas from the suction port through the suction flow passage, a compression stroke for compressing the gas, and a discharge stroke for discharging the compressed gas to the discharge port through the discharge flow passage.
- the suction flow passage communicates in the rotor axial direction with the working chambers that are in the suction stroke.
- the suction flow passage includes a male rotor side suction flow passage provided on the male rotor side and besides on the downstream side with respect to a virtual plane that passes a central axis of the male rotor and a central axis of the female rotor (in other words, on the opposite side to the suction port), and a female rotor side suction flow passage provided on the female rotor side and besides on the downstream side with respect to the virtual plane described above.
- Patent Document 1 JP-2012-041910-A (for example, refer to FIGS. 8 and 9)
- a flow passage wall on the outer side in a rotor radial direction of the male rotor side suction flow passage (except a portion for confining gas to the working chamber) is located on the outer side in the rotor radial direction with respect to the wall of the bore. Therefore, as a component of a flow of the gas flowing from the male rotor side suction flow passage toward the male rotor side working chamber, a component in the rotor radial direction appears, and this makes a cause of increase in pressure loss.
- a flow passage wall on the outer side, in a rotor radial direction, of the female rotor side suction flow passage (except a portion for confining gas to the working chamber) is located on the outer side in the rotor radial direction with respect to the wall of the bore. Therefore, as a component of a flow of the gas flowing from the female rotor side suction flow passage toward the female rotor side working chamber, a component in the rotor radial direction appears, and this makes a cause of increase in pressure loss.
- the present invention has been made in view of such matters as described above, and reducing the pressure loss in a suction flow passage is one of subjects of the present invention.
- the present invention includes a plurality of means for solving the problem described above, and an example of the means is a screw compressor including a male rotor having a lobed portion; a female rotor having a lobed portion that engages with the lobed portion of the male rotor; and a casing that accommodates the male rotor and the female rotor.
- the casing includes: a bore that accommodates the lobed portion of the male rotor and the lobed portion of the female rotor therein such that working chambers on a male rotor side and working chambers on a female rotor side are formed in lobe grooves of the lobed portions; a suction port located on an outer side in a rotor radial direction with respect to the lobed portion of the male rotor and the lobed portion of the female rotor; and a suction flow passage formed so as to connect the suction port to working chambers that are in a suction stroke and communicating in a rotor axial direction with the working chambers that are in the suction stroke.
- the suction flow passage includes: a male rotor side suction flow passage located on the male rotor side and besides on a downstream side with respect to a virtual plane that passes a central axis of the male rotor and a central axis of the female rotor; and a female rotor side suction flow passage located on the female rotor side and besides on the downstream side with respect to the virtual plane.
- the male rotor side suction flow passage is formed such that a flow passage wall on the outer side in the rotor radial direction is located at a position same as that of a wall of the bore as viewed from the rotor axial direction at least within a range of one half of an axial pitch of the lobed portion of the male rotor from a suction side end surface of the lobed portion in the rotor axial direction.
- the pressure loss in the suction flow passage can be reduced.
- FIG. 1 is a schematic view depicting a configuration of a screw compressor of the oil feeding type according to an embodiment of the present invention.
- FIG. 2 is a vertical sectional view depicting a structure of a compressor main body in the embodiment of the present invention.
- FIG. 3 is a horizontal sectional view taken along line III-III of FIG. 2 .
- FIG. 4 is a vertical sectional view taken along line IV-IV of FIG. 2 .
- FIG. 5 is a vertical sectional view taken along line V-V of FIG. 2 .
- FIG. 6 is a horizontal sectional view depicting a structure of a compressor main body in a modification of the present invention.
- FIGS. 1 to 5 An embodiment of the present invention is described with reference to FIGS. 1 to 5 .
- the screw compressor of the present embodiment includes a motor 1 , a compressor main body 2 driven by the motor 1 to compress air (gas), a gas-liquid separator 3 that separates compressed air discharged from the compressor main body 2 from oil (liquid) included in the compressed air, and an oil pipe 4 that supplies the oil separated by the gas-liquid separator 3 to the compressor main body 2 (particularly, to working chambers, suction side bearings, and discharge side bearings hereinafter described).
- the oil pipe 4 is provided with an oil cooler 5 for cooling the oil, an oil filter 6 for removing impurities in the oil, and so forth.
- the compressor main body 2 includes a male rotor 11 A and a female rotor 11 B that are screw rotors, and a casing 12 that accommodates the male rotor 11 A and the female rotor 11 B therein.
- the male rotor 11 A has a lobed portion 13 A having a plurality of (in the present embodiment, four) lobes extending spirally, a suction side shaft portion 14 A connected to one side (left side in FIGS. 2 and 3 ) in an axial direction of the lobed portion 13 A, and a discharge side shaft portion 15 A connected to the other side (right side in FIGS. 2 and 3 ) in the axial direction of the lobed portion 13 A.
- the suction side shaft portion 14 A of the male rotor 11 A is rotatably supported by a suction side bearing 16 A
- the discharge side shaft portion 15 A of the male rotor 11 A is rotatably supported on a discharge side bearing 17 A.
- the female rotor 11 B has a lobed portion 13 B having a plurality of (in the present embodiment, six) lobes extending spirally, a suction side shaft portion 14 B connected to one side (left side in FIGS. 2 and 3 ), in the axial direction, of the lobed portion 13 B, and a discharge side shaft portion 15 B connected to the other side (right side in FIGS. 2 and 3 ), in the axial direction, of the lobed portion 13 B.
- the suction side shaft portion 14 B of the female rotor 11 B is rotatably supported by a suction side bearing 16 B
- the discharge side shaft portion 15 B of the female portion 11 B is rotatably supported by a discharge side bearing 17 B.
- the suction side shaft portion 14 A of the male rotor 11 A extends through the casing 12 and is coupled to a rotary shaft of the motor 1 .
- the male rotor 11 A is rotated by driving of the motor 1
- the female rotor 11 B is rotated through engagement of the lobed portion 13 A of the male rotor 11 A and the lobed portion 13 B of the female rotor 11 B.
- the casing 12 is configured from a main casing 18 , a suction side casing 19 coupled to one side (left side in FIGS. 2 and 3 ), in the axial direction, of the main casing 18 and a discharge side casing 20 coupled to the opposite side (right side in FIGS. 2 and 3 ), in the axial direction, of the main casing 18 .
- the casing 12 has a bore 21 that accommodates the lobed portion 13 A of the male rotor 11 A and the lobed portion 13 B of the female rotor 11 B such that working chambers on the male rotor side and working chambers on the female rotor side are formed in lobe grooves of them.
- the bore 21 is configured such that two cylindrical holes, in which the lobed portion 13 A of the male rotor 11 A and the lobed portion 13 B of the female rotor 11 B are individually accommodated, partially overlap with each other.
- the casing 12 has a suction port 22 located on the outer side in a rotor radial direction (upper side in FIG. 2 ) with respect to the lobed portion 13 A of the male rotor 11 A and the lobed portion 13 B of the female rotor 11 B, and a suction flow passage 23 formed so as to connect the suction port 22 to working chambers that are in a suction stroke.
- the bore 21 , suction port 22 , and suction flow passage 23 are formed in the main casing 18 .
- the casing 12 has a discharge port 24 located on the outer side (lower side in FIG. 2 ) in a rotor radial direction with respect to the lobed portion 13 A of the male rotor 11 A and the lobed portion 13 B of the female rotor 11 B, and a discharge flow passage 25 formed so as to connect the discharge port to working chambers that are in a discharge stroke.
- the discharge port 24 is formed in the discharge side casing 20
- the discharge flow passage 25 is formed in the discharge side casing 20 and the main casing 18 .
- the working chamber is changed in volume while moving from one side to the other side in the rotor axial direction. Consequently, the working chamber sequentially performs a suction stroke for sucking gas from the suction port 22 through the suction flow passage 23 , a compression stroke for compressing the gas, and a discharge stroke for discharging the compressed gas to the discharge port 24 through the discharge flow passage 25 .
- the suction flow passage 23 communicates in the rotor axial direction with working chambers that are in the suction stroke. Further, the suction flow passage 23 has a male rotor side suction flow passage 26 A located on the male rotor 11 A side and besides on the downstream side (in other words, on the opposite side to the suction port 22 ) with respect to a virtual plane C that passes the central axis O 1 of the male rotor 11 A and the central axis O 2 of the female rotor 11 B, and a female rotor side suction flow passage 26 B located on the female rotor 11 B side and besides on the downstream side with respect to the virtual plane C (refer to FIGS. 3 and 4 ).
- the axial pitch of the lobed portion signifies a distance between lobe tips in the rotor axial direction.
- the flow passage wall 27 A being at the same position as that of the wall of the bore 21 when viewed in the rotor axial direction signifies that the radial position of the flow passage wall 27 A with reference to the central axis O 1 of the male rotor 11 A falls within a range of 95% to 105% of the radial position of the wall of the bore 21 .
- a component in the rotor radial direction is less likely to appear, and therefore, the pressure loss can be reduced. Further, since a component of the rotor radial direction is less likely to appear as a component of a flow of gas flowing from the female rotor side suction flow passage 26 B to the female rotor side working chamber, the pressure loss can be reduced. As a result, increase in the suction flow amount and reduction of power can be achieved.
- the male rotor side suction flow passage 26 A or the female rotor side suction flow passage 26 B does not have the characteristic within at least the range of one half of the axial pitch of the lobed portion from the suction side end surface of the lobed portion of the rotor in the rotor axial direction, a sufficient advantage cannot be obtained.
- the male rotor side suction flow passage 26 A is formed such that the area V 1 (refer to FIG. 3 ) of each flow passage cross section that is a rotor axial cross section taken along each radial direction of the male rotor 11 A is greater than the area S 1 (refer to FIG. 5 ) of the rotor radial cross section of each working chamber on the male rotor side (in other words, a cross section extending in rotor radial directions), and the female rotor side suction flow passage 26 B is formed such that the area V 2 (refer to FIG.
- FIG. 6 is a horizontal sectional view representing a structure of a compressor main body in the present modification.
- the male rotor side suction flow passage 26 A is formed such that the area V 1 (refer to FIG. 6 ) of each flow passage cross section that is a rotor axial cross section taken along each radial direction of the male rotor 11 A is the same as the cross sectional area S 1 (refer to FIG. 5 ) in a rotor radial direction of each working chamber on the male water side at least within a range of a rotational pitch (in the present embodiment, 90 degrees) of the lobed portion 13 A of the male rotor 11 A from the virtual plane C in the direction of rotation of the male rotor 11 A.
- a rotational pitch in the present embodiment, 90 degrees
- the rotational pitch of the lobed portion signifies an angle between adjacent lobe tips in the direction of rotor rotation.
- the area V 1 being the same as the area S 1 signifies that the area V 1 falls within a range of 95% to 105% of the area S 1 .
- the female rotor side suction flow passage 26 B is formed such that the area V 2 (refer to FIG. 6 ) of each flow passage cross section that is a rotor axial cross section taken along each radial direction of the female rotor 11 B is the same as the area S 2 (refer to FIG. 5 ) of the rotor radial cross section of each working chamber on the female rotor side at least within a range of the rotational pitch (in the present embodiment, 45 degrees) of the lobed portion 13 B of the female rotor 11 B from the virtual plane C in the direction of rotation of the female rotor 11 B.
- the area V 2 being the same as the area S 2 signifies that the area V 2 falls within a range of 95% to 105% of the area S 2 .
- the change in the flow velocity in the male rotor side suction flow passage 26 A or the change in the flow velocity from the male rotor side suction flow passage 26 A to the male rotor side working chamber can be suppressed to further reduce the pressure loss.
- the change in the flow velocity in the female rotor side suction flow passage 26 B or the change in the flow velocity from the female rotor side suction flow passage 26 B to the female rotor side working chamber can be suppressed to further reduce the pressure loss.
- both the male rotor side suction flow passage 26 A and the female rotor side suction flow passage 26 B have a first characteristic (more particularly, the characteristic that the flow passage wall on the outer side in the rotor radial direction is located at a position that is the same as that of the wall of the bore 21 as viewed in the rotor axial direction at least within the range of one half of the axial pitch of the lobed portion from the suction side end surface of the lobed portion in the rotor axial direction), this is not restrictive.
- only one of the male rotor side suction flow passage 26 A and the female rotor side suction flow passage 26 B may have the first characteristic.
- both the male rotor side suction flow passage 26 A and the female rotor side suction flow passage 26 B have the first characteristic and a second characteristic (more particularly, the characteristic that they are formed such that the area of each flow passage cross section that is a rotor axial cross section taken along each radial direction of the rotor is the same as the area of the rotor radial cross section of each working chamber at least within the range of the rotational pitch of the lobed portion from the virtual plane C in the direction of rotation of the rotor), this is not restrictive.
- only one of the male rotor side suction flow passage 26 A and the female rotor side suction flow passage 26 B may have the first characteristic and the second characteristic.
- both the male rotor side suction flow passage 26 A and the female rotor side suction flow passage 26 B may have the first characteristic while only one of the male rotor side suction flow passage 26 A and the female rotor side suction flow passage 26 B has the second characteristic.
- the screw compressor of the oil feeding type (more particularly, in which oil is supplied into the working chambers) is taken as an example of the application target of the present invention, this is not restrictive, and the application target of the present invention may be a screw compressor of the water feeding type (more particularly, in which water is supplied into the working chambers) or a screw compressor of the no liquid feeding type (more particularly, in which such liquid as oil or water is not supplied into the working chambers).
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Abstract
Description
- The present invention relates to a screw compressor including a suction port positioned on the outer side in a rotor radial direction and a suction flow passage that communicates in a rotor axial direction with a working chamber.
- The screw compressor described in
Patent Document 1 includes a male rotor having a lobed portion, a female rotor having a lobed portion that engages with the lobed portion of the male rotor, and a casing that accommodates the male rotor and the female rotor therein. - The casing has a bore that accommodates the lobed portion of the male rotor and the lobed portion of the female rotor therein such that working chambers on the male rotor side and working chambers on the female rotor side are formed in lobe grooves of the lobed portions. Further, the casing has a suction port located on the outer side in a rotor radial direction with respect to the lobed portion of the male rotor and the lobed portion of the female rotor, and a suction flow passage formed so as to connect the suction port to the working chambers that are in a suction stroke. The casing further has a discharge port located on the outer side in the rotor radial direction from the lobed portion of the male rotor and the lobed portion of the female rotor, and a discharge flow passage formed so as to connect the discharge port to the working chambers that are in a discharge stroke.
- The working chamber is changed in volume while moving from one side to the other side in the rotor axial direction. Consequently, the working chamber sequentially performs a suction stroke for sucking gas from the suction port through the suction flow passage, a compression stroke for compressing the gas, and a discharge stroke for discharging the compressed gas to the discharge port through the discharge flow passage.
- The suction flow passage communicates in the rotor axial direction with the working chambers that are in the suction stroke. Further, the suction flow passage includes a male rotor side suction flow passage provided on the male rotor side and besides on the downstream side with respect to a virtual plane that passes a central axis of the male rotor and a central axis of the female rotor (in other words, on the opposite side to the suction port), and a female rotor side suction flow passage provided on the female rotor side and besides on the downstream side with respect to the virtual plane described above.
- Patent Document 1: JP-2012-041910-A (for example, refer to FIGS. 8 and 9)
- In
Patent Document 1, a flow passage wall on the outer side in a rotor radial direction of the male rotor side suction flow passage (except a portion for confining gas to the working chamber) is located on the outer side in the rotor radial direction with respect to the wall of the bore. Therefore, as a component of a flow of the gas flowing from the male rotor side suction flow passage toward the male rotor side working chamber, a component in the rotor radial direction appears, and this makes a cause of increase in pressure loss. - Similarly, a flow passage wall on the outer side, in a rotor radial direction, of the female rotor side suction flow passage (except a portion for confining gas to the working chamber) is located on the outer side in the rotor radial direction with respect to the wall of the bore. Therefore, as a component of a flow of the gas flowing from the female rotor side suction flow passage toward the female rotor side working chamber, a component in the rotor radial direction appears, and this makes a cause of increase in pressure loss.
- The present invention has been made in view of such matters as described above, and reducing the pressure loss in a suction flow passage is one of subjects of the present invention.
- In order to solve the problem described above, the configuration described in the claims is applied. The present invention includes a plurality of means for solving the problem described above, and an example of the means is a screw compressor including a male rotor having a lobed portion; a female rotor having a lobed portion that engages with the lobed portion of the male rotor; and a casing that accommodates the male rotor and the female rotor. The casing includes: a bore that accommodates the lobed portion of the male rotor and the lobed portion of the female rotor therein such that working chambers on a male rotor side and working chambers on a female rotor side are formed in lobe grooves of the lobed portions; a suction port located on an outer side in a rotor radial direction with respect to the lobed portion of the male rotor and the lobed portion of the female rotor; and a suction flow passage formed so as to connect the suction port to working chambers that are in a suction stroke and communicating in a rotor axial direction with the working chambers that are in the suction stroke. The suction flow passage includes: a male rotor side suction flow passage located on the male rotor side and besides on a downstream side with respect to a virtual plane that passes a central axis of the male rotor and a central axis of the female rotor; and a female rotor side suction flow passage located on the female rotor side and besides on the downstream side with respect to the virtual plane. The male rotor side suction flow passage is formed such that a flow passage wall on the outer side in the rotor radial direction is located at a position same as that of a wall of the bore as viewed from the rotor axial direction at least within a range of one half of an axial pitch of the lobed portion of the male rotor from a suction side end surface of the lobed portion in the rotor axial direction.
- According to the present invention, the pressure loss in the suction flow passage can be reduced.
- It is to be noted that problems, configurations and advantages other than those described above are made clear from the following description.
-
FIG. 1 is a schematic view depicting a configuration of a screw compressor of the oil feeding type according to an embodiment of the present invention. -
FIG. 2 is a vertical sectional view depicting a structure of a compressor main body in the embodiment of the present invention. -
FIG. 3 is a horizontal sectional view taken along line III-III ofFIG. 2 . -
FIG. 4 is a vertical sectional view taken along line IV-IV ofFIG. 2 . -
FIG. 5 is a vertical sectional view taken along line V-V ofFIG. 2 . -
FIG. 6 is a horizontal sectional view depicting a structure of a compressor main body in a modification of the present invention. - An embodiment of the present invention is described with reference to
FIGS. 1 to 5 . - The screw compressor of the present embodiment includes a
motor 1, a compressormain body 2 driven by themotor 1 to compress air (gas), a gas-liquid separator 3 that separates compressed air discharged from the compressormain body 2 from oil (liquid) included in the compressed air, and anoil pipe 4 that supplies the oil separated by the gas-liquid separator 3 to the compressor main body 2 (particularly, to working chambers, suction side bearings, and discharge side bearings hereinafter described). Theoil pipe 4 is provided with anoil cooler 5 for cooling the oil, anoil filter 6 for removing impurities in the oil, and so forth. - The compressor
main body 2 includes amale rotor 11A and afemale rotor 11B that are screw rotors, and acasing 12 that accommodates themale rotor 11A and thefemale rotor 11B therein. - The
male rotor 11A has alobed portion 13A having a plurality of (in the present embodiment, four) lobes extending spirally, a suctionside shaft portion 14A connected to one side (left side inFIGS. 2 and 3 ) in an axial direction of thelobed portion 13A, and a dischargeside shaft portion 15A connected to the other side (right side inFIGS. 2 and 3 ) in the axial direction of thelobed portion 13A. The suctionside shaft portion 14A of themale rotor 11A is rotatably supported by a suction side bearing 16A, and the dischargeside shaft portion 15A of themale rotor 11A is rotatably supported on a discharge side bearing 17A. - Similarly, the
female rotor 11B has alobed portion 13B having a plurality of (in the present embodiment, six) lobes extending spirally, a suctionside shaft portion 14B connected to one side (left side inFIGS. 2 and 3 ), in the axial direction, of thelobed portion 13B, and a dischargeside shaft portion 15B connected to the other side (right side inFIGS. 2 and 3 ), in the axial direction, of thelobed portion 13B. The suctionside shaft portion 14B of thefemale rotor 11B is rotatably supported by a suction side bearing 16B, and the dischargeside shaft portion 15B of thefemale portion 11B is rotatably supported by a discharge side bearing 17B. - The suction
side shaft portion 14A of themale rotor 11A extends through thecasing 12 and is coupled to a rotary shaft of themotor 1. Thus, themale rotor 11A is rotated by driving of themotor 1, and also thefemale rotor 11B is rotated through engagement of thelobed portion 13A of themale rotor 11A and thelobed portion 13B of thefemale rotor 11B. - The
casing 12 is configured from amain casing 18, asuction side casing 19 coupled to one side (left side inFIGS. 2 and 3 ), in the axial direction, of themain casing 18 and adischarge side casing 20 coupled to the opposite side (right side inFIGS. 2 and 3 ), in the axial direction, of themain casing 18. - The
casing 12 has abore 21 that accommodates the lobedportion 13A of themale rotor 11A and thelobed portion 13B of thefemale rotor 11B such that working chambers on the male rotor side and working chambers on the female rotor side are formed in lobe grooves of them. Thebore 21 is configured such that two cylindrical holes, in which thelobed portion 13A of themale rotor 11A and thelobed portion 13B of thefemale rotor 11B are individually accommodated, partially overlap with each other. - The
casing 12 has asuction port 22 located on the outer side in a rotor radial direction (upper side inFIG. 2 ) with respect to thelobed portion 13A of themale rotor 11A and thelobed portion 13B of thefemale rotor 11B, and asuction flow passage 23 formed so as to connect thesuction port 22 to working chambers that are in a suction stroke. Thebore 21,suction port 22, andsuction flow passage 23 are formed in themain casing 18. - The
casing 12 has adischarge port 24 located on the outer side (lower side inFIG. 2 ) in a rotor radial direction with respect to thelobed portion 13A of themale rotor 11A and thelobed portion 13B of thefemale rotor 11B, and adischarge flow passage 25 formed so as to connect the discharge port to working chambers that are in a discharge stroke. Thedischarge port 24 is formed in thedischarge side casing 20, and thedischarge flow passage 25 is formed in thedischarge side casing 20 and themain casing 18. - The working chamber is changed in volume while moving from one side to the other side in the rotor axial direction. Consequently, the working chamber sequentially performs a suction stroke for sucking gas from the
suction port 22 through thesuction flow passage 23, a compression stroke for compressing the gas, and a discharge stroke for discharging the compressed gas to thedischarge port 24 through thedischarge flow passage 25. - The
suction flow passage 23 communicates in the rotor axial direction with working chambers that are in the suction stroke. Further, thesuction flow passage 23 has a male rotor sidesuction flow passage 26A located on themale rotor 11A side and besides on the downstream side (in other words, on the opposite side to the suction port 22) with respect to a virtual plane C that passes the central axis O1 of themale rotor 11A and the central axis O2 of thefemale rotor 11B, and a female rotor sidesuction flow passage 26B located on thefemale rotor 11B side and besides on the downstream side with respect to the virtual plane C (refer toFIGS. 3 and 4 ). - Here, as a significant characteristic of the present embodiment, a
flow passage wall 27A on the outer side, in the rotor radial direction, of the male rotor sidesuction flow passage 26A (except aportion 28 for confining gas to the working chambers) is formed such that it is located at a position that is the same as that of a wall of thebore 21 as viewed in the rotor axial direction at least within a range of one half of an axial pitch P1 (refer toFIG. 3 ) of thelobed portion 13A (as a particular example, within a range of P1×0.8=R1 inFIG. 3 , within a range of P1×0.5=R1 inFIG. 6 hereinafter described) from a suction side end surface of thelobed portion 13A of themale rotor 11A in the rotor axial direction. It is to be noted that the axial pitch of the lobed portion signifies a distance between lobe tips in the rotor axial direction. Further, since a working error and so forth are taken into consideration, with regard to theflow passage wall 27A, being at the same position as that of the wall of thebore 21 when viewed in the rotor axial direction signifies that the radial position of theflow passage wall 27A with reference to the central axis O1 of themale rotor 11A falls within a range of 95% to 105% of the radial position of the wall of thebore 21. - Further, a
flow passage wall 27B on the outer side, in the rotor radial direction, of the female rotor sidesuction flow passage 26B (except theportion 28 for confining gas to the working chambers) is formed such that it is located at a position that is the same as that of the wall of thebore 21 as viewed in the rotor axial direction at least within a range of one half of an axial pitch P2 (P1=P2; refer toFIG. 3 ) of thelobed portion 13B from a suction side end surface of thelobed portion 13B of thefemale rotor 11B in the rotor axial direction (as a particular example, inFIG. 3 , within a range of P2×0.8=R2; inFIG. 6 hereinafter described, within a range of P2×0.5=R2). It is to be noted that, since a working error and so forth are taken into consideration, with regard to theflow passage wall 27B, being at the same position as that of the wall of thebore 21 as viewed in the rotor axial direction signifies that the radial position of theflow passage wall 27B with reference to the central axis O2 of thefemale rotor 11B falls within a range of 95% to 105% of the radial position of the wall of thebore 21. - In such an embodiment as described above, as a component of a flow of gas flowing from the male rotor side
suction flow passage 26A to the male rotor side working chamber, a component in the rotor radial direction is less likely to appear, and therefore, the pressure loss can be reduced. Further, since a component of the rotor radial direction is less likely to appear as a component of a flow of gas flowing from the female rotor sidesuction flow passage 26B to the female rotor side working chamber, the pressure loss can be reduced. As a result, increase in the suction flow amount and reduction of power can be achieved. - Further, in comparison with an alternative case in which the
flow passage walls bore 21, accumulating of oil into a lower portion of the male rotor sidesuction flow passage 26A and the female rotor sidesuction flow passage 26B at the time of stop of the compressormain body 2 can be suppressed. Therefore, also the pressure loss by an influence of oil accumulated in a lower portion of the male rotor sidesuction flow passage 26A and the female rotor sidesuction flow passage 26B can be suppressed. - Supplemental description is given to the reason why the range within which the
flow passage walls bore 21 as viewed in the rotor axial direction is determined as a range of at least one half of the axial pitch of the lobed portion of the rotor from the suction side end surface of the lobed portion in the rotor axial direction. From the point of view of the volume efficiency of the screw compressor, it is necessary to take into consideration the area of a rotor axial cross section of the male rotor sidesuction flow passage 26A with respect to the area of a rotor axial cross section of the male rotor side working chamber (in other words, a cross section extending in the rotor axial direction) and the area of the rotor axial cross section of the female rotor sidesuction flow passage 26B with respect to the area of the rotor axial cross section of the female rotor side working chamber. Since the area of the rotor axial cross section of the male rotor side working chamber is represented, for example, by (difference between the outer diameter of the lobes of the male rotor and the outer diameter of the shaft) xaxial pitch 2, for the area of the rotor axial cross section of the male rotor sidesuction flow passage 26A, it is better to assure at least (difference between the outer diameter of the lobes of the male rotor and the outer diameter of the shaft) x axial pitch=2. Similarly, since the area of the rotor axial cross section of the female rotor side working chamber is represented, for example, by (difference between the outer diameter of the lobes of the female rotor and the outer diameter of the shaft)×axial pitch=2, for the area of the rotor axial cross section of the female rotor sidesuction flow passage 26A, it is better to assure at least (difference between the outer diameter of the lobes of the female rotor and the outer diameter of the shaft) x axial pitch=2. From such a point of view, if the male rotor sidesuction flow passage 26A or the female rotor sidesuction flow passage 26B does not have the characteristic within at least the range of one half of the axial pitch of the lobed portion from the suction side end surface of the lobed portion of the rotor in the rotor axial direction, a sufficient advantage cannot be obtained. - It is to be noted that, although the embodiment described above is described taking as an example of a case in which the male rotor side
suction flow passage 26A is formed such that the area V1 (refer toFIG. 3 ) of each flow passage cross section that is a rotor axial cross section taken along each radial direction of themale rotor 11A is greater than the area S1 (refer toFIG. 5 ) of the rotor radial cross section of each working chamber on the male rotor side (in other words, a cross section extending in rotor radial directions), and the female rotor sidesuction flow passage 26B is formed such that the area V2 (refer toFIG. 3 ) of each flow passage cross section that is a rotor axial cross section taken along each radial direction of thefemale rotor 11B is greater than the area S2 (refer toFIG. 5 ) of the rotor radial cross section of each working chamber on the female rotor side, this is not restrictive. A modification of the present invention is described with reference toFIG. 6 .FIG. 6 is a horizontal sectional view representing a structure of a compressor main body in the present modification. - In the present modification, the male rotor side
suction flow passage 26A is formed such that the area V1 (refer toFIG. 6 ) of each flow passage cross section that is a rotor axial cross section taken along each radial direction of themale rotor 11A is the same as the cross sectional area S1 (refer toFIG. 5 ) in a rotor radial direction of each working chamber on the male water side at least within a range of a rotational pitch (in the present embodiment, 90 degrees) of thelobed portion 13A of themale rotor 11A from the virtual plane C in the direction of rotation of themale rotor 11A. It is to be noted that the rotational pitch of the lobed portion signifies an angle between adjacent lobe tips in the direction of rotor rotation. Further, since a working error and so forth are taken into consideration, the area V1 being the same as the area S1 signifies that the area V1 falls within a range of 95% to 105% of the area S1. - Meanwhile, the female rotor side
suction flow passage 26B is formed such that the area V2 (refer toFIG. 6 ) of each flow passage cross section that is a rotor axial cross section taken along each radial direction of thefemale rotor 11B is the same as the area S2 (refer toFIG. 5 ) of the rotor radial cross section of each working chamber on the female rotor side at least within a range of the rotational pitch (in the present embodiment, 45 degrees) of thelobed portion 13B of thefemale rotor 11B from the virtual plane C in the direction of rotation of thefemale rotor 11B. It is to be noted that, since a working error and so forth are taken into consideration, the area V2 being the same as the area S2 signifies that the area V2 falls within a range of 95% to 105% of the area S2. - In such a modification as described above, the change in the flow velocity in the male rotor side
suction flow passage 26A or the change in the flow velocity from the male rotor sidesuction flow passage 26A to the male rotor side working chamber can be suppressed to further reduce the pressure loss. Further, the change in the flow velocity in the female rotor sidesuction flow passage 26B or the change in the flow velocity from the female rotor sidesuction flow passage 26B to the female rotor side working chamber can be suppressed to further reduce the pressure loss. - It is to be noted that, although the foregoing description of the embodiment is given taking as an example of a case in which both the male rotor side
suction flow passage 26A and the female rotor sidesuction flow passage 26B have a first characteristic (more particularly, the characteristic that the flow passage wall on the outer side in the rotor radial direction is located at a position that is the same as that of the wall of thebore 21 as viewed in the rotor axial direction at least within the range of one half of the axial pitch of the lobed portion from the suction side end surface of the lobed portion in the rotor axial direction), this is not restrictive. In particular, only one of the male rotor sidesuction flow passage 26A and the female rotor sidesuction flow passage 26B may have the first characteristic. - Further, although the foregoing description of the modification is given taking as an example of a case in which both the male rotor side
suction flow passage 26A and the female rotor sidesuction flow passage 26B have the first characteristic and a second characteristic (more particularly, the characteristic that they are formed such that the area of each flow passage cross section that is a rotor axial cross section taken along each radial direction of the rotor is the same as the area of the rotor radial cross section of each working chamber at least within the range of the rotational pitch of the lobed portion from the virtual plane C in the direction of rotation of the rotor), this is not restrictive. For example, only one of the male rotor sidesuction flow passage 26A and the female rotor sidesuction flow passage 26B may have the first characteristic and the second characteristic. Further, for example, both the male rotor sidesuction flow passage 26A and the female rotor sidesuction flow passage 26B may have the first characteristic while only one of the male rotor sidesuction flow passage 26A and the female rotor sidesuction flow passage 26B has the second characteristic. - Further, although the screw compressor of the oil feeding type (more particularly, in which oil is supplied into the working chambers) is taken as an example of the application target of the present invention, this is not restrictive, and the application target of the present invention may be a screw compressor of the water feeding type (more particularly, in which water is supplied into the working chambers) or a screw compressor of the no liquid feeding type (more particularly, in which such liquid as oil or water is not supplied into the working chambers).
- 11A: Male rotor
- 11B: Female rotor
- 12: Casing
- 13A, 13B: Lobed portion
- 21: Bore
- 22: Suction port
- 23: Suction flow passage
- 26A: Male rotor side suction flow passage
- 26B: Female rotor side suction flow passage
- 27A: Flow passage wall on the outer side, in the rotor radial direction, of male rotor side suction flow passage
- 27B: Flow passage wall on the outer side, in the rotor radial direction, of female rotor side suction flow passage
Claims (6)
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2018-227315 | 2018-12-04 | ||
JP2018227315A JP7189749B2 (en) | 2018-12-04 | 2018-12-04 | screw compressor |
PCT/JP2019/038674 WO2020116007A1 (en) | 2018-12-04 | 2019-10-01 | Screw compressor |
Publications (1)
Publication Number | Publication Date |
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US20220049700A1 true US20220049700A1 (en) | 2022-02-17 |
Family
ID=70975215
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US17/298,720 Abandoned US20220049700A1 (en) | 2018-12-04 | 2019-10-01 | Screw Compressor |
Country Status (5)
Country | Link |
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US (1) | US20220049700A1 (en) |
JP (1) | JP7189749B2 (en) |
CN (1) | CN113167275A (en) |
TW (1) | TWI720701B (en) |
WO (1) | WO2020116007A1 (en) |
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Publication number | Priority date | Publication date | Assignee | Title |
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CN116480588B (en) * | 2023-04-18 | 2024-02-23 | 北京通嘉宏瑞科技有限公司 | Stator and vacuum pump |
Family Cites Families (7)
Publication number | Priority date | Publication date | Assignee | Title |
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JPS6117191U (en) * | 1984-07-04 | 1986-01-31 | 株式会社神戸製鋼所 | Screw compressor |
WO1998042951A1 (en) * | 1997-03-26 | 1998-10-01 | Zakrytoe Aktsionernoe Obschestvo 'nezavisimaya Energetika' | Steam-driven propeller engine |
JP5177081B2 (en) * | 2009-06-01 | 2013-04-03 | 株式会社日立プラントテクノロジー | Screw compressor |
JP5478362B2 (en) * | 2010-05-25 | 2014-04-23 | 株式会社日立製作所 | Screw compressor |
JP5759125B2 (en) * | 2010-08-23 | 2015-08-05 | 北越工業株式会社 | Structure of suction part of screw compressor body |
MY176126A (en) | 2011-10-07 | 2020-07-24 | Takeda Pharmaceuticals Co | 1-arylcarbonyl-4-oxy-piperidine compounds useful for the treatment of neurodegenerative diseases |
JP7075721B2 (en) * | 2017-04-10 | 2022-05-26 | 日立ジョンソンコントロールズ空調株式会社 | Screw compressor |
-
2018
- 2018-12-04 JP JP2018227315A patent/JP7189749B2/en active Active
-
2019
- 2019-10-01 WO PCT/JP2019/038674 patent/WO2020116007A1/en active Application Filing
- 2019-10-01 CN CN201980079092.8A patent/CN113167275A/en active Pending
- 2019-10-01 US US17/298,720 patent/US20220049700A1/en not_active Abandoned
- 2019-11-26 TW TW108142886A patent/TWI720701B/en active
Also Published As
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JP2021028474A (en) | 2021-02-25 |
WO2020116007A1 (en) | 2020-06-11 |
CN113167275A (en) | 2021-07-23 |
TW202022233A (en) | 2020-06-16 |
JP7189749B2 (en) | 2022-12-14 |
TWI720701B (en) | 2021-03-01 |
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