Abstract: An axial-flow exhaust turbine is capable of discharging water drops collected from a steam passage. The axial-flow exhaust turbine includes: a steam passage in which rotor blades and stator blades are arranged in rows; an exhaust chamber for discharging steam from the steam passage in a turbine axial direction, the exhaust chamber being positioned at a downstream side of the steam passage; a casing including the steam passage and the exhaust chamber inside the casing; an inner partition wall positioned on an inner circumferential side of the casing so as to face the exhaust chamber; and a drain flow channel defined between the casing and the inner partition wall. The water drops collected from the steam passage can pass through the drain flow channel.

Abstract: An object is to provide an axial-flow exhaust turbine capable of discharging a drain from a steam passage smoothly, reducing cost upon replacement, and saving space. An axial-flow exhaust turbine includes: a steam passage in which rotor blades and stator blades are arranged in rows; an exhaust chamber for discharging steam from the steam passage in a turbine axial direction disposed at a downstream side of the steam passage; a casing including the steam passage and the exhaust chamber inside the casing; an inner partition wall disposed on an inner circumferential side of the casing so as to face the exhaust chamber; and a drain flow channel formed between the casing and the inner partition wall. A drain collected from the steam passage can pass through the drain flow channel.

Abstract: The bearing device has a support ring positioned around a rotating shaft and a plurality of bearing pads provided between the rotating shaft and the support ring and configured to support the rotating shaft. Some of the plurality of bearing pads are positioned at a lower side of the rotating shaft, and a key member is installed between the support ring and a carrier ring supporting the plurality of bearing pads. The key member is inserted therebetween in a tangential direction of an outer circumference of the carrier ring and is configured to perform positioning of the plurality of bearing pads and the support ring in a radial direction.

Abstract: The bearing device is provided with: a support ring positioned around a rotating shaft; and a plurality of bearing pads provided between the rotating shaft and the support ring and configured to support the rotating shaft, wherein some of the plurality of bearing pads are positioned at a lower side of the rotating shaft, and a key member is installed between the support ring and a carrier ring supporting the plurality of bearing pads, wherein the key member is inserted therebetween in a tangential direction of an outer circumference of the carrier ring and is configured to perform positioning of the plurality of bearing pads and the support ring in a radial direction.

Abstract: A spindle motor includes a stationary portion and a rotating portion. The rotating portion includes a magnet arranged around a central axis extending in a vertical direction. The stationary portion includes a base member and a magnetic member arranged below the magnet and fixed to the base member. The base member includes an upper surface extending out perpendicularly or substantially perpendicularly to the central axis, and a wall surface extending in an axial direction. The magnetic member includes an annular plate portion arranged on the base member and a projecting portion arranged to extend downward from the plate portion. At least a portion of the projecting portion is arranged to be in contact with the wall surface. An adhesive is arranged between the plate portion and the upper surface of the base member and between the projecting portion and the wall surface.

Abstract: A stationary portion of a spindle motor includes a base member and a magnetic member. The magnetic member is arranged below a magnet and fixed to the base member. The magnetic member includes an annular plate portion arranged on an upper surface of the base member, and a projecting portion arranged to extend from the plate portion in an axial direction. At least a portion of the projecting portion is press fitted to a wall surface of the base member.

Abstract: A bearing device includes a shaft, a sleeve and a thrust plate. The shaft includes a convex portion having a curved surface provided at one end thereof. The sleeve includes an inner circumferential surface opposed to an outer circumferential surface of the shaft. The thrust plate includes a concave portion having a curved surface and arranged to make contact with the convex portion of the shaft. The shaft is supported by the sleeve and the thrust plate such that it may rotate about the central axis with respect to the sleeve and the thrust plate. A curvature radius of the concave portion is greater than a curvature radius of the convex portion but equal to or smaller than about 2.0 times of the curvature radius of the convex portion.

Abstract: In a shaft sealing mechanism which prevents fluid from flowing in an axial direction of a rotor through an annular gap between the rotor and a stator, there are provided a high pressure side plate positioned on a high pressure side region of a plurality of sheets, and a low pressure side plate positioned on a low pressure side region of the plurality of sheets, and construction is such that in a state in which the plurality of sheets is fixed on a stator side, and when under gas pressure, the sheets make contact with each other.

Abstract: A stationary portion of a spindle motor includes a base member and a magnetic member. The magnetic member is arranged below a magnet and fixed to the base member. The magnetic member includes an annular plate portion arranged on an upper surface of the base member, and a projecting portion arranged to extend from the plate portion in an axial direction. At least a portion of the projecting portion is press fitted to a wall surface of the base member.

Abstract: A bearing device includes a shaft, a sleeve and a thrust plate. The shaft includes a convex portion having a curved surface provided at one end thereof. The sleeve includes an inner circumferential surface opposed to an outer circumferential surface of the shaft. The thrust plate includes a concave portion having a curved surface and arranged to make contact with the convex portion of the shaft. The shaft is supported by the sleeve and the thrust plate such that it may rotate about the central axis with respect to the sleeve and the thrust plate. A curvature radius of the concave portion is greater than a curvature radius of the convex portion but equal to or smaller than about 2.0 times of the curvature radius of the convex portion.

Abstract: A method for manufacturing a bearing mechanism includes the steps of: (a) setting a position of an annular member relative to a center axis; (b) moving the annular member toward an opening of a sleeve housing through a shaft by pressing and elastically deforming a bottom portion of the sleeve housing; (c) releasing the pressing to restore the bottom portion to its original shape; and (d) fixing the annular member to the sleeve housing. Herein, the step (b) is performed by arranging the annular member within the sleeve housing, making one end portion of the shaft received in the annular member contact an inner bottom surface of the sleeve housing or with a thrust member disposed thereon, and making the annular member contact the shaft in a direction leading from the opening to the bottom portion of the sleeve housing.

Abstract: A bearing mechanism includes a cylindrical bottom-closed sleeve unit; a shaft unit radially supported by the sleeve unit via a lubricant; and an elastic thrust plate on an inner bottom surface of the sleeve unit to contact an end portion of the shaft unit at a position on a central axis to rotatably support the shaft unit. The shaft unit has a first contact portion, and the sleeve unit has a second contact portion. The contact portions are so arranged that, when a force acting from above the inner bottom surface is applied, movement of the shaft unit is restrained by the contact portions making contact with each other. Further, a distance between the contact portions prior to the force being applied is smaller than the displacement of the shaft unit at which the thrust plate gets so pressed by the shaft unit to be permanently deformed.

Abstract: A leaf seal as a shaft seal mechanism is made compact and enables reduction of manufacturing cost. Plural thin plates 29 lapped one on another in layers have their outer circumferential proximal ends fixed to each other by welding so that an annular thin plate assembly 29A having flexibility is formed. This thin plate assembly 29A is bent and assembled to form the leaf seal 25.

Abstract: A shaft seal mechanism (leaf seal) by which a desired seal performance can be stably obtained is provided. The shaft seal mechanism comprises a concave groove 71 formed larger than a minimum size of a plate width of thin plates 29 and a fitting piece 61 fitted in a gap between the concave groove 71 and a leaf seal 25. The leaf seal 25 comprises an annular thin plate assembly 29A constructed by the thin plates 29 and a plate spring 56 integrally formed therewith supporting the annular thin plate assembly 29A to be levitated coaxially with a rotating shaft 23. The thin plates 29 have their outer circumferential proximal end side made movable relative to the concave groove 71. A shaft seal mechanism assembling structure is also provided comprising a pressure receiving surface 61b and a lower pressure side plate 54 forming a predetermined gap size between the pressure receiving surface 61b and one side edges of the thin plates 29.

Abstract: There is provided a shaft sealing mechanism in which, even in a case where eccentricity occurs in a parent machine, flutter behavior of the sheets can be reliably prevented, the sheets can be prevented from failing due to fatigue, and also a long life and reliability of the shaft sealing mechanism can be improved. In a shaft sealing mechanism which prevents fluid from flowing in an axial direction of a rotor through an annular gap between the rotor and a stator, there are provided a high pressure side plate positioned on a high pressure side region of a plurality of sheets, and a low pressure side plate positioned on a low pressure side region of a plurality of sheets, and the construction is such that in a state in which the plurality of sheets is fixed on the stator side, and when under gas pressure, the parts make contact with each other.

Abstract: A shaft seal mechanism (leaf seal) by which a desired seal performance can be stably obtained is provided. The shaft seal mechanism comprises a concave groove 71 formed larger than a minimum size of a plate width of thin plates 29 aid a fitting piece 61 fitted in a gap between the concave groove 71 and a leaf seal 25. The leaf seal 25 comprises an annular thin plate assembly 29A constructed by the thin plates 29 and a plate spring 56 integrally formed therewith supporting the annular thin plate assembly 29A to be levitated coaxially with a rotating shaft 23. The thin plates 29 have their outer circumferential proximal end side made movable relative to the concave groove 71. A shaft seal mechanism assembling structure is also provided comprising a pressure receiving surface 61b and a lower pressure side plate 54 forming a predetermined gap size between the pressure receiving surface 61b and one side edges of the thin plates 29.

Abstract: A leaf seal as a shaft seal mechanism is made compact and enables reduction of manufacturing cost. Plural thin plates 29 lapped one on another in layers have their outer circumferential proximal ends fixed to each other by welding so that an annular thin plate assembly 29A having a flexibility is formed. This thin plate assembly 29A is bent and assembled to form the leaf seal 25.

Abstract: In manufacturing an exhaust pipe of two-passage construction, a metallic plate having a first end and a second end respectively elongated in a longitudinal direction of the exhaust pipe is prepared. The metallic plate is bent into a substantially S shape in cross section. It has a diametrically extending central partition plate and a substantially semicircular peripheral wall on each lateral side of said partition plate in such a manner that a groove of substantially V shape in cross section having a substantially closed end on a radially inner side and an open end on a radially outer side is formed at each diametrically outer portion of the partition plate. A target is provided so as to elongate along the groove in a manner to extend substantially radially outward from the closed end. A welding arc is generated between the target and a welding gun disposed on a side of the open end such that the substantially closed end and the target are welded together.

Abstract: In manufacturing an exhaust pipe of two-passage construction, a metallic plate having a first end and a second end respectively elongated in a longitudinal direction of the exhaust pipe is prepared. The metallic plate is bent into a substantially S shape in cross section. It has a diametrically extending central partition plate and a substantially semicircular peripheral wall on each lateral side of said partition plate in such a manner that a groove of substantially V shape in cross section having a substantially closed end on a radially inner side and an open end on a radially outer side is formed at each diametrically outer portion of the partition plate. A target is provided so as to elongate along the groove in a manner to extend substantially radially outward from the closed end. A welding arc is generated between the target and a welding gun disposed on a side of the open end such that the substantially closed end and the target are welded together.

Abstract: In manufacturing an exhaust pipe of two-passage construction, a metallic plate having a first end and a second end respectively elongated in a longitudinal direction of the exhaust pipe is prepared. The metallic plate is bent into a substantially S shape in cross section. It has a diametrically extending central partition plate and a substantially semicircular peripheral wall on each lateral side of said partition plate in such a manner that a groove of substantially V shape in cross section having a substantially closed end on a radially inner side and an open end on a radially outer side is formed at each diametrically outer portion of the partition plate. A target is provided so as to elongate along the groove in a manner to extend substantially radially outward from the closed end. A welding arc is generated between the target and a welding gun disposed on a side of the open end such that the substantially closed end and the target are welded together.