Abstract: A centrifugal air blower includes a fan; and a scroll casing. The scroll casing includes: a sidewall covering the fan from an axial direction of a rotation axis, the sidewall having a suction opening for sucking air; a discharge opening; a tongue portion for guiding the airflow to the discharge opening; a peripheral wall surrounding the fan from a radial direction of the rotation axis; and a bell mouth formed along the suction opening of the sidewall. The bell mouth includes upstream and downstream ends, with the upstream end being an end portion on an upstream side in a direction of flow of the air passing through the suction opening, and the downstream end being an end portion on a downstream side in the direction of flow of the air.

Abstract: A centrifugal air blower includes a fan; and a scroll casing. The scroll casing includes: a sidewall covering the fan from an axial direction of a rotation axis, the sidewall having a suction opening for sucking air; a discharge opening; a tongue portion for guiding the airflow to the discharge opening; a peripheral wall surrounding the fan from a radial direction of the rotation axis; and a bell mouth formed along the suction opening of the sidewall. The bell mouth includes upstream and downstream ends, with the upstream end being an end portion on an upstream side in a direction of flow of the air passing through the suction opening, and the downstream end being an end portion on a downstream side in the direction of flow of the air.

Abstract: A centrifugal air blower includes a fan; and a scroll casing. The scroll casing includes: a sidewall covering the fan from an axial direction of a rotation axis, the sidewall having a suction opening for sucking air; a discharge opening; a tongue portion for guiding the airflow to the discharge opening; a peripheral wall surrounding the fan from a radial direction of the rotation axis; and a bell mouth formed along the suction opening of the sidewall. The bell mouth includes upstream and downstream ends, with the upstream end being an end portion on an upstream side in a direction of flow of the air passing through the suction opening, and the downstream end being an end portion on a downstream side in the direction of flow of the air.

Abstract: A centrifugal air blower comprises a fan (2); and a scroll casing (4). The scroll casing includes: a sidewall (4c) covering the fan (2) from an axial direction of a rotation axis on which the fan (2) rotates, the side wall having a suction opening for sucking air; a discharge opening (41) for discharging an airflow generated by the fan (2); a tongue portion (4b) for guiding the airflow to the discharge opening (41); a peripheral wall (4a) surrounding the fan (2) from a radial direction of the rotation axis; and a bell mouth (3) formed along the suction opening (5) of the sidewall (4c). The bell mouth (3) includes an upstream end (3a) and a downstream end (3b), the upstream end being an end portion on an upstream side in a direction of flow of the air passing through the suction opening (5), the downstream end being an end portion on a downstream side in the direction of flow of the air.

Abstract: A centrifugal air blower comprises a fan; and a scroll casing. The scroll casing includes: a sidewall covering the fan from an axial direction of a rotation axis on which the fan rotates, the side wall having a suction opening for sucking air; a discharge opening for discharging an airflow generated by the fan; a tongue portion for guiding the airflow to the discharge opening; a peripheral wall surrounding the fan from a radial direction of the rotation axis; and a bell mouth formed along the suction opening of the sidewall. The bell mouth includes an upstream end and a downstream end, the upstream end being an end portion on an upstream side in a direction of flow of the air passing through the suction opening, the downstream end being an end portion on a downstream side in the direction of flow of the air.

Abstract: A centrifugal air blower comprises a fan (2); and a scroll casing (4). The scroll casing includes: a sidewall (4c) covering the fan (2) from an axial direction of a rotation axis on which the fan (2) rotates, the side wall having a suction opening for sucking air; a discharge opening (41) for discharging an airflow generated by the fan (2); a tongue portion (4b) for guiding the airflow to the discharge opening (41); a peripheral wall (4a) surrounding the fan (2) from a radial direction of the rotation axis; and a bell mouth (3) formed along the suction opening (5) of the sidewall (4c). The bell mouth (3) includes an upstream end (3a) and a downstream end (3b), the upstream end being an end portion on an upstream side in a direction of flow of the air passing through the suction opening (5), the downstream end being an end portion on a downstream side in the direction of flow of the air.

Abstract: A centrifugal air blower comprises a fan; and a scroll casing. The scroll casing includes: a sidewall covering the fan from an axial direction of a rotation axis on which the fan rotates, the side wall having a suction opening for sucking air; a discharge opening for discharging an airflow generated by the fan; a tongue portion for guiding the airflow to the discharge opening; a peripheral wall surrounding the fan from a radial direction of the rotation axis; and a bell mouth formed along the suction opening of the sidewall. The bell mouth includes an upstream end and a downstream end, the upstream end being an end portion on an upstream side in a direction of flow of the air passing through the suction opening, the downstream end being an end portion on a downstream side in the direction of flow of the air.

Abstract: A centrifugal fan includes: an impeller driven by a drive motor to rotate; a scroll casing including an inlet-port face having an opening and a wall portion having positions at which distances from an axis line that is a rotation center of the impeller differ from each other, and changing an air flow in a centrifugal direction generated by rotation of the impeller into an air flow in one direction; an air admitting portion including a bell mouth portion having a large-diameter side end placed on an inlet-air-flow upstream side of the inlet-port face; and a protruding portion extending from the air admitting portion in a direction orthogonal to the axis line, which is the rotation center of the impeller, and in a direction away from the rotation center and surrounding part of the bell mouth portion.

Abstract: A centrifugal fan includes: an impeller driven by a drive motor to rotate; a scroll casing including an inlet-port face having an opening and a wall portion having positions at which distances from an axis line that is a rotation center of the impeller differ from each other, and changing an air flow in a centrifugal direction generated by rotation of the impeller into an air flow in one direction; an air admitting portion including a bell mouth portion having a large-diameter side end placed on an inlet-air-flow upstream side of the inlet-port face; and a protruding portion extending from the air admitting portion in a direction orthogonal to the axis line, which is the rotation center of the impeller, and in a direction away from the rotation center and surrounding part of the bell mouth portion.

Abstract: A brass is a base material, and a material containing Mn and Si is cast to make a ring material. Ametallic structure in the cross section of the ring material is under a condition where an intermetallic compound Mn5Si3 is uniformly and finely scattered and precipitated in the base material (brass composed of &agr;- and &bgr;-phase). A machined retainer provided by matching said material has an excellent sizing precision, sound affect resistance.

Abstract: A cage is made of a low carbon steel and is for use in a rolling bearing which includes an outer ring, an inner ring and a plurality of rolling elements disposed rotationally between the outer ring and the inner ring. The cage includes a plurality of pockets for retaining the rolling elements in an equi-distribution in the rotating direction of the rolling elements. The low carbon steel is a steel containing from 0.02 to 0.10% by weight of C and from 0.10 to 0.45% by weight of Mn and is subjected to plastic working. The hardness for the pocket surface at least at a portion in contact with the rolling element is Hv 190 to 270, and the hardness for the core portion in the cage section is Hv 110 to 170.

Abstract: A cage for use in a rolling bearing made of low carbon steel for use in a rolling bearing comprising an outer ring, an inner ring and a plurality of rolling elements disposed rotationally between the outer ring and the inner ring and having pockets for retaining the rolling elements in an equi distribution in the rotating direction of the rolling element is constituted with a steel containing from 0.02 to 0.10% by weight of C and from 0.10 to 0.45% by weight of Mn, in which the hardness for the surface at least at a portion in contact with the rolling element is Hv 190 or more and the hardness for the inside is Hv 110 to 170, the cage for use in the rolling bearing described above being a high strength cage causing less deformation or fracture and having a stable performance.

Abstract: In a steel cage for rolling bearing which is nitrided to form a compound layer on the surface thereof, when the thickness of a dense layer in the compound layer 1 is predetermined to a range of from 3 &mgr;m to 20 &mgr;m, the abrasion can be inhibited, improving the abrasion resistance. Further, when a porous layer which acts as a lubricant reservoir is predetermined to a range of from 2 &mgr;m to 25 &mgr;m, the exhaustion of lubricant can be inhibited, improving the seizing resistance.