Daikin Industries, Ltd.

Uacj Corporation

Tadashi Okada

Hiromichi Ueno

Harunori Miyamura

Kaname Ohtsuka

Takanori Murono

Takayuki Takahashi

Toshihiro Susa

Yasunaga Itoh

Kosuke Nishimura

Kaoru Ueda

A screw compressor includes a screw rotor having a plurality of helical grooves, and a gate rotor with gates to mesh with the helical grooves. Each of the gates first and second seal lines to come into contact with side wall surfaces of the helical grooves. Shapes of the first and second seal lines are asymmetric with respect to a first imaginary straight line passing through a rotation center of the gate rotor and a first intermediate position located on a tip end side of each of the gates between the first and second seal lines. A second imaginary straight line passing through the rotation center and a second intermediate position located on a base end side of each of the gates between the first and second seal lines is inclined with respect to the first imaginary straight line. The helical grooves have shapes corresponding to the gates.

Screw compressor and refrigeration apparatus

A screw compressor includes a casing, a screw rotor accommodated in the casing to be rotationally driven, and a gate rotor assembly configured to rotate with rotation of the screw rotor. The gate rotor assembly includes a gate rotor including a plurality of flat plate-shaped gates configured to mesh with a helical groove of the screw rotor, and first and second support members. The first support member is made of a metal and includes a plurality of first gate support portions to support corresponding gates from a back surface side. The second support member is made of a metal and includes an annular portion having an annular shape and a plurality of second gate support portions each extending radially toward an outer side from an outer peripheral portion of the annular portion to support corresponding gates from a front surface side.

A plurality of helical grooves are formed in a workpiece having a cylindrical shape. Each of grooves is divided into a first portion including an end portion on a first end side of the workpiece and a second portion including an end portion on a second end side of the workpiece. A method of manufacturing a screw rotor of a screw compressor includes attaching a first end of the workpiece to a holder of a machine tool, finishing the first portion of each of the plurality of helical grooves by cutting, detaching the workpiece from the holder, attaching a second end of the workpiece detached from the holder to the holder, and finishing the second portion of each of the plurality of helical grooves by cutting.

Method for manufacturing screw rotor

A closed impeller includes an impeller body including a plurality of blade portions, and a shroud fitted on the impeller body. The shroud is press formed into a curved shape along end portions of the blade portions. The shroud includes a plurality of protrusions protruding from a surface facing the impeller body and extending, and curved, along the end portions of the plurality of blade portions. An amount of protrusion of each of the protrusions is less than a thickness of the shroud. A brazing material is provided at least on end portions of the protrusions.

Closed impeller and method for producing closed impeller

A closed impeller () includes an impeller main body (), which is composed of an aluminum alloy and has blades () that protrude from a hub (). A shroud () covers the blades. The blades and the shroud are joined together by brazed joints (). The shroud () is formed from a brazing sheet () that comprises a core material (), which is composed of an aluminum alloy, and a filler material layer (), which is disposed on an outermost surface () of the shroud that opposes or faces the blades when the shroud is brazed to the blades.

Closed impeller and method of manufacturing the same

A processed article is manufactured with a tool including a cutting blade. The cutting blade is arranged to be in contact with two machined segment surfaces so that two contact points are defined between the two machined segment surfaces and the cutting blade in a corner. A machining pitch is set in a pick feed direction of the tool at the corner to a first machining pitch for when a part of the cutting blade corresponding to a projected shape of a side surface of the cutting blade having a first curvature radius is a cutting point. A cut is performed along a feed direction in the two adjacent machined segment surfaces successively at the corner so that the tool proceeds toward the corner in one of the machined segment surfaces and away from the corner in the other one of the machined segment surfaces.

Method for manufacturing processed article, tool path calculation method, processed article, and impeller

In a single screw compressor, gates () of gate rotors () are to be engaged with spiral grooves () of a screw rotor (). In each spiral groove () of the screw rotor (), an area extending from a start point of the spiral groove () to a position in a compression stroke is a suction-side portion (), and the remaining portion (portion up to a terminal point of the spiral groove ()) is a discharge-side portion (). In the discharge-side portion (), a clearance between a wall surface () therein and the gate () is substantially '0 (zero).' A clearance between the wall surface () in the suction-side portion () and the gate () is wider than that between the wall surface () in the discharge-side portion () and the gate (), and is gradually narrowed from the start point toward the terminal point in the spiral groove ().

Single screw compressor

In a screw rotor (), a first suction-side area () is formed in a first side wall surface () of a spiral groove (). In the first side wall surface (), a portion extending from a start point to a point until immediately before a compression chamber () is in a completely-closed state defines the first suction-side area (). The first suction-side area () is thinner than a portion of the first side wall surface () other than the first suction-side area (), and does not contact a gate () of a gate rotor ().

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Osaka, Japan

Tadashi Okada