US 11,873,817 B2
Liquid-feeding rotary-screw compressor
Takeshi Tsuchiya, Tokyo (JP); Kotaro Chiba, Tokyo (JP); Masahiko Takano, Tokyo (JP); Shigeyuki Yorikane, Tokyo (JP); and Kenji Morita, Tokyo (JP)
Assigned to Hitachi Industrial Equipment Systems Co., Ltd., Tokyo (JP)
Appl. No. 17/771,715
Filed by Hitachi Industrial Equipment Systems Co., Ltd., Tokyo (JP)
PCT Filed Sep. 10, 2020, PCT No. PCT/JP2020/034230
§ 371(c)(1), (2) Date Apr. 25, 2022,
PCT Pub. No. WO2021/084925, PCT Pub. Date May 6, 2021.
Claims priority of application No. 2019-197820 (JP), filed on Oct. 30, 2019.
Prior Publication US 2022/0403845 A1, Dec. 22, 2022
Int. Cl. F01C 1/16 (2006.01); F03C 2/00 (2006.01); F03C 4/00 (2006.01); F04C 2/00 (2006.01); F04C 29/12 (2006.01); F04C 18/16 (2006.01); F04C 18/20 (2006.01)
CPC F04C 29/12 (2013.01) [F04C 18/16 (2013.01); F04C 18/20 (2013.01); F04C 2250/102 (2013.01)] 7 Claims
OG exemplary drawing
 
1. A liquid-feeding rotary-screw compressor comprising:
a male rotor having a delivery end on one side in an axial direction;
a female rotor having a delivery end on the one side in the axial direction; and
a casing having an accommodating chamber that rotatably accommodates the male rotor and the female rotor in a mutually meshed state, and a delivery port that opens in the axial direction and is formed at a delivery inner wall surface of the accommodating chamber, the delivery inner wall surface being opposed to the delivery end of the male rotor and the delivery end of the female rotor, wherein
a first working chamber and a second working chamber that open only in the axial direction are formed by meshing of the male rotor and the female rotor at the delivery ends,
the delivery port includes:
a first opening having a profile configured to interrupt communication with the second working chamber of the first working chamber and the second working chamber, the second working chamber being increased in volume with rotation of the male rotor and the female rotor;
a second opening connected to the first opening; and
a third opening connected to the first opening and the second opening,
the profile of the first opening includes:
when a point obtained by projecting an intersection of a reference line passing through an axis of the male rotor and an axis of the female rotor, a tip circle of the male rotor, and a root circle of the female rotor onto the delivery inner wall surface is made to be a reference point,
a first profile line that constitutes one of a pair of lateral edges of a lingulate protrusion configured to close off the second working chamber and that extends toward the reference point;
a second profile line that constitutes another one of the pair of lateral edges of the lingulate protrusion;
a first connection line that constitutes a tip edge of the lingulate protrusion and connects the first profile line and the second profile line to each other;
a third profile line that extends toward the reference point along a part of a curve obtained by projecting the root circle of the female rotor onto the delivery inner wall surface; and
a second connection line that connects the first profile line and the third profile line to each other,
the second opening includes a first groove formed on the delivery inner wall surface, the first groove opening into the first opening at a position of the second connection line and extending from the position of the second connection line toward the reference line in such a range as not to exceed the reference line, and
the third opening includes a second groove formed on the delivery inner wall surface, the second groove having a one-side end portion opening into the first groove, opening into the first opening at a position of the first profile line, and extending along the first profile line.