US 12,442,374 B2
Screw compressor with improved suction flow
Takeshi Tsuchiya, Tokyo (JP); Kotaro Chiba, Tokyo (JP); Toshiaki Yabe, Tokyo (JP); Kohei Sakai, Tokyo (JP); Yuki Taniyama, Tokyo (JP); Sho Nikaido, Tokyo (JP); and Shotaro Sano, Tokyo (JP)
Assigned to HITACHI INDUSTRIAL EQUIPMENT SYSTEMS CO., LTD., Tokyo (JP)
Appl. No. 18/843,632
Filed by HITACHI INDUSTRIAL EQUIPMENT SYSTEMS CO., LTD., Tokyo (JP)
PCT Filed Mar. 3, 2023, PCT No. PCT/JP2023/008100
§ 371(c)(1), (2) Date Sep. 3, 2024,
PCT Pub. No. WO2023/176517, PCT Pub. Date Sep. 21, 2023.
Claims priority of application No. 2022-040336 (JP), filed on Mar. 15, 2022.
Prior Publication US 2025/0188929 A1, Jun. 12, 2025
Int. Cl. F04C 18/16 (2006.01); F04C 29/12 (2006.01)
CPC F04C 18/16 (2013.01) [F04C 29/12 (2013.01); F04C 2240/30 (2013.01); F04C 2250/101 (2013.01)] 8 Claims
OG exemplary drawing
 
1. A screw compressor comprising:
a male rotor that has a first rotor lobe section and is rotatable around a first axis line;
a female rotor that has a second rotor lobe section and is rotatable around a second axis line;
a casing that has a housing chamber for housing the first rotor lobe section and the second rotor lobe section in a state of being meshed with each other and forming a plurality of working chambers; and
a suction flow path disposed in the casing configured to introduce working fluid from an outside of the casing to working chambers in a suction process, the suction flow path including:
a male-side flow path that opens in an axial direction of the male rotor with respect to working chambers on the male rotor side among the working chambers in the suction process and that extends from a first starting end to a first termination end, the first starting end being positioned on one side with respect to a virtual plane passing through the first axis line and the second axis line and being on an inflow side of the working fluid, the first termination end being positioned on other side with respect to the virtual plane, and
a female-side flow path that opens in an axial direction of the female rotor with respect to working chambers on the female rotor side among the working chambers in the suction process and that extends from a second starting end to a second termination end, the second starting end being positioned on the one side with respect to the virtual plane and being on the inflow side of the working fluid, the second termination end being positioned on the other side with respect to the virtual plane,
wherein the male-side flow path includes a male-side first flow path wall that faces a suction-side end face side of the first rotor lobe section and extends from the first starting end to the first termination end,
wherein the female-side flow path includes a female-side first flow path wall that faces a suction-side end face side of the second rotor lobe section and extends from the second starting end to the second termination end,
wherein the male-side first flow path wall is configured such that at least a partial area in a range from the first starting end to the first termination end is closer to the first rotor lobe section from the first starting end side toward the first termination end side, or the female-side first flow path wall is configured such that at least a partial area in a range from the second starting end to the second termination end is closer to the second rotor lobe section from the second starting end side toward the second termination end side,
wherein the male-side first flow path wall has an inclined face that is gradually closer to the first rotor lobe section from the first starting end side toward the first termination end side, or the female-side first flow path wall has an inclined face that is gradually closer to the second rotor lobe section from the second starting end side toward the second termination end side, and
wherein the male-side first flow path wall is configured such that the inclined face extends from a position on the one side with respect to the virtual plane to a certain first position before reaching the first termination end, and such that an area from the first position to the first termination end is a flat face equally distant from the first rotor lobe section, or the female-side first flow path wall is configured such that the inclined face extends from a position on the one side with respect to the virtual plane to a certain second position before reaching the second termination end, and such that an area from the second position to the second termination end is equally distant from the second rotor lobe section.