Abstract: A coupling guard for covering a coupling which couples a drive shaft of a prime mover and a rotational shaft of a rotary machine to each other. The coupling guard includes a cylindrical guard body having an upper semicylindrical member and a lower semicylindrical member coupled to the upper semicylindrical member, and a guard leg supporting the guard body. The guard body has a flange portion to which the guard leg is attached. The guard leg includes a vertical wall parallel to a central axis of the guard body, an upper wall, a bottom wall, a left-side wall, and a right-side wall which project perpendicularly outwardly from the vertical wall. The vertical wall, the upper wall, the bottom wall, the left-side wall, and the right-side wall are made of a single plate material.

Abstract: There is disclosed a coupling guard that can easily be installed and removed while a drive shaft of a prime mover and a rotational shaft of a rotary machine are coupled to each other. The coupling guard includes a cylindrical guard body having an upper semicylindrical member and a lower semicylindrical member coupled to the upper semicylindrical member, and a guard leg supporting the guard body. The guard body has a flange portion to which the guard leg is attached. The guard leg includes a vertical wall parallel to a central axis of the guard body, an upper wall, a bottom wall, a left-side wall, and a right-side wall which project perpendicularly outwardly from the vertical wall. The vertical wall, the upper wall, the bottom wall, the left-side wall, and the right-side wall are made of a single plate material.

Abstract: A rotatable apparatus includes a casing and a protector for closing an opening. The casing includes first and second casing faces intersecting at angle ?1. The first casing face is provided with an opening. The protector includes first and second protector faces abutting and intersecting each other at angle ?2. The protector is fixed to only the second casing face. The angle ?2 is larger than the angle ?1 when the protector is removed from the casing. The protector is attached to the casing in such a manner that the second protector face is fixed to the second casing face, and that the first protector face is elastically deformed so that an edge part of the first protector face, which is located on the side opposite to the second protector face, closely contacts the first casing face.

Abstract: A non-clogging type pump impeller includes: a fluid passage provided in an approximately cylindrical body and connecting a suction port to a discharge port. The fluid passage has a vortex shape as viewed from an axial direction. A first recess, which is sunk downwardly in the axial direction, is formed on a first end surface of the approximately cylindrical body so as to surround a boss. A second recess, which is sunk upwardly in the axial direction, is formed on a second end surface of the approximately cylindrical body so as to surround the suction port. At least one communication hole provides fluid communication between the first recess and the second recess. Sewage in the second recess is introduced into the first recess through the at least one communication hole to thereby effectively remove an air pocket trapped on the first end surface of the impeller and in the first recess.

Abstract: A shaft coupling guard is used to cover a shaft coupling that couples a main shaft of a prime mover and a main shaft of a driven apparatus as a rotatable apparatus driven by the prime mover. The shaft coupling guard includes a guard main body formed so as to extend in a direction along an axis and having a tubular shape for circumferentially covering the shaft coupling. The guard main body includes a guard main body upper portion, and a guard main body lower portion configured to be detachable from the guard main body upper portion. The shaft coupling guard further includes a leg portion formed integrally with the guard main body and configured to support the guard main body.

Abstract: A rotatable apparatus includes a casing and a protector for closing an opening. The casing includes first and second casing faces intersecting at angle ?1. The first casing face is provided with an opening. The protector includes first and second protector faces abutting and intersecting each other at angle ?2. The protector is fixed to only the second casing face. The angle ?2 is larger than the angle ?1 when the protector is removed from the casing. The protector is attached to the casing in such a manner that the second protector face is fixed to the second casing face, and that the first protector face is elastically deformed so that an edge part of the first protector face, which is located on the side opposite to the second protector face, closely contacts the first casing face.

Abstract: A shaft coupling guard is used to cover a shaft coupling that couples a main shaft of a prime mover and a main shaft of a driven apparatus as a rotatable apparatus driven by the prime mover. The shaft coupling guard includes a guard main body formed so as to extend in a direction along an axis and having a tubular shape for circumferentially covering the shaft coupling. The guard main body includes a guard main body upper portion, and a guard main body lower portion configured to be detachable from the guard main body upper portion. The shaft coupling guard further includes a leg portion formed integrally with the guard main body and configured to support the guard main body.

Abstract: A submersible motor pump includes a water jacket having a circulation passage of a coolant, a centrifugal impeller for circulating the coolant, a suction passage configured to provide fluid communication between the circulation passage and a fluid inlet of the centrifugal impeller, and a discharge passage configured to provide fluid communication between a fluid outlet of the centrifugal impeller and the circulation passage. The discharge passage includes a heat-exchange passage formed by two wall surfaces, one of which is constituted by a member which contacts a liquid conveyed by a main impeller. The heat-exchange passage has a circular shape extending radially outwardly from the fluid outlet of the centrifugal impeller. The heat-exchange passage includes at least one axial passage section having a length component in an axial direction of the rotational shaft.

Abstract: A ceramics sliding member for use in ultrapure water or pure water of the present invention is made of a non-continuous-pore SiC sintered body. The non-continuous-pore SiC sintered body includes ?-SiC at a ratio of 20% by weight or more thereto and has an average crystal structure whose aspect ratio is 2 or greater.

Abstract: A submersible motor pump includes a water jacket having a circulation passage of a coolant, a centrifugal impeller for circulating the coolant, a suction passage configured to provide fluid communication between the circulation passage and a fluid inlet of the centrifugal impeller, and a discharge passage configured to provide fluid communication between a fluid outlet of the centrifugal impeller and the circulation passage. The discharge passage includes a heat-exchange passage formed by two wall surfaces, one of which is constituted by a member which contacts a liquid conveyed by a main impeller. The heat-exchange passage has a circular shape extending radially outwardly from the fluid outlet of the centrifugal impeller. The heat-exchange passage includes at least one axial passage section having a length component in an axial direction of the rotational shaft.

Abstract: A non-clogging type pump impeller (1) includes: a fluid passage (18) provided in an approximately cylindrical body (10) and connecting a suction port (13) to a discharge port (14). The fluid passage (18) has a vortex shape as viewed from the axial direction. A first recess (21), which is sunk downwardly in the axial direction, is formed on one end surface (11) of the body (10) so as to surround a boss (12). A second recess (22), which is sunk upwardly in the axial direction, is formed on the other end surface (15) of the body (10) so as to surround the suction port (13). One or more communication hole (23) provides fluid communication between the first recess (21) and the second recess (22). Sewage in the second recess (22) is introduced into the first recess (21) through the communication hole (23) to thereby effectively remove air pocket trapped on the upper end surface (11) of the impeller (1) and in the first recess (21).

Abstract: A submersible motor pump includes a water jacket having a circulation passage of a coolant, a centrifugal impeller for circulating the coolant, a suction passage configured to provide fluid communication between the circulation passage and a fluid inlet of the centrifugal impeller, and a discharge passage configured to provide fluid communication between a fluid outlet of the centrifugal impeller and the circulation passage. The discharge passage includes a heat-exchange passage formed by two wall surfaces, one of which is constituted by a member which contacts a liquid conveyed by a main impeller. The heat-exchange passage has a circular shape extending radially outwardly from the fluid outlet of the centrifugal impeller. The heat-exchange passage includes at least one axial passage section having a length component in an axial direction of the rotational shaft.

Abstract: A ceramics sliding member for use in ultrapure water or pure water of the present invention is made of an SiC sintered body. The SiC sintered body includes ?-SiC at a ratio of 20% or more thereto and has an average crystal structure whose aspect ratio is 2 or greater.

Abstract: A centrifugal pump includes a diffuser section for decreasing a velocity of the fluid discharged from an impeller, a return vane for leading the fluid which has passed through the diffuser section to a discharge side, and a main plate to which the diffuser section and the return vane are fixed.

Abstract: A seal mechanism (10) can reduce noise during operation. The seal mechanism (10) is used for a fluid machine (P) to prevent a fluid from leaking out of a high-pressure space (H) into a low-pressure space (L) in the fluid machine (P). The seal mechanism (10) has an annular seal member (12) movable in a radial direction and a housing (11) disposed between a body (23) of the fluid machine (P) and a rotatable member (22) located inside the body (23) of the fluid machine (P) so as to receive the annular seal member (12). The annular seal member (12) has a first surface (12a) on a side of the low-pressure space (L) in the fluid machine (P). The housing (11) has a second surface (11c) facing the first surface (12a) of the annular seal member (12). The seal mechanism (10) has one or more passages (15) formed in the first surface (12a) and/or the second surface (11c).

Abstract: A centrifugal pump includes at least one impeller (11) fixed to a main shaft (10) and at least one casing which houses the impeller and is formed through press working of sheet metal such as a steel plate. The centrifugal pump further includes a casing cover configured to seal an open end of the casing hermetically, and a shaft seal device (12) provided at a portion where the main shaft passes through the casing cover. The casing cover has a thick member (6) made of castings, and a thin corrosion-resistant lining member (40) which is tightly fixed to the thick member.

Abstract: The present invention relates to a centrifugal pump whose components such as an impeller and a casing are manufactured from a sheet metal and a method of manufacturing such a centrifugal pump. The centrifugal pump according to the present invention comprises a diffuser section (11) for decreasing a velocity of the fluid discharged from an impeller, a return vane (14) for leading the fluid which has passed through the diffuser section (11) to a discharge side, a main plate (12) to which the diffuser section (11) and the return vane (14) are fixed, and a structural member (13) for smoothening a step (17) formed in a passage extending from the diffuser section (11) to the return vane (14).

Abstract: The centrifugal impeller includes a plurality of blades (3), a plurality of fluid paths (P) for delivering a fluid from an impeller inlet (1) to an impeller outlet (2), and a shroud (4) and a hub (5) for forming the fluid paths (P). Each of the fluid paths (P) is formed between adjacent two of the blades (3). A curved line (L3) of the shroud (4) curves so as to project toward the hub (5) in a region from a blade inlet (A) to a predetermined position (C) of the blade (3), and the curved line (L3) curves so as to project toward the opposite side of the hub (5) in a region from the predetermined position (C) to a blade outlet (B).

Abstract: A seal mechanism (10) can reduce noise during operation. The seal mechanism (10) is used for a fluid machine (P) to prevent a fluid from leaking out of a high-pressure space (H) into a low-pressure space (L) in the fluid machine (P). The seal mechanism (10) has an annular seal member (12) movable in a radial direction and a housing (11) disposed between a body (23) of the fluid machine (P) and a rotatable member (22) located inside the body (23) of the fluid machine (P) so as to receive the annular seal member (12). The annular seal member (12) has a first surface (12a) on a side of the low-pressure space (L) in the fluid machine (P). The housing (11) has a second surface (11c) facing the first surface (12a) of the annular seal member (12). The seal mechanism (10) has one or more passages (15) formed in the first surface (12a) and/or the second surface (11c).

Abstract: The centrifugal impeller includes a plurality of blades (3), a plurality of fluid paths (P) for delivering a fluid from an impeller inlet (1) to an impeller outlet (2), and a shroud (4) and a hub (5) for forming the fluid paths (P). Each of the fluid paths (P) is formed between adjacent two of the blades (3). A curved line (L3) of the shroud (4) curves so as to project toward the hub (5) in a region from a blade inlet (A) to a predetermined position (C) of the blade (3), and the curved line (L3) curves so as to project toward the opposite side of the hub (5) in a region from the predetermined position (C) to a blade outlet (B).