Abstract: A vibration detection device includes an A/D conversion unit for receiving a sine wave signal of an AE wave corresponding to vibration generated in a target machine from an AE sensor that detects the AE wave and converting the received sine wave signal into digital data, an extraction unit for extracting, from the digital data, a data point of a local maximum value for each cycle of the sine wave signal, and an output processing unit for outputting the data point extracted by the extraction unit and cycle data including data points with the number of points which can be recognized as a sine wave and including the data point of a local maximum value so that an output unit visibly outputs the data point and the cycle data.

Abstract: In a blower fan according to a preferred embodiment of the present invention, a side wall portion includes a tongue portion arranged to project between an air outlet and an impeller. A side surface of the tongue portion includes a tongue portion tip arranged to touch a first imaginary plane including a central axis; a first tongue portion side surface arranged to extend from the tongue portion tip along an outer envelope of the impeller; and a second tongue portion side surface arranged to extend from the tongue portion tip toward a side edge, the side edge being a line of intersection of the air outlet and the side wall portion. The second tongue portion side surface is arranged to cross a second imaginary plane including the central axis and touching the side edge.

Abstract: In a blower fan according to a preferred embodiment of the present invention, a side wall portion includes a tongue portion arranged to project between an air outlet and an impeller. A side surface of the tongue portion includes a tongue portion tip arranged to touch a first imaginary plane including a central axis; a first tongue portion side surface arranged to extend from the tongue portion tip along an outer envelope of the impeller; and a second tongue portion side surface arranged to extend from the tongue portion tip toward a side edge, the side edge being a line of intersection of the air outlet and the side wall portion. The second tongue portion side surface is arranged to cross a second imaginary plane including the central axis and touching the side edge.

Abstract: A lower plate includes a lower air inlet arranged radially outward of a bearing portion. In a plan view, a plane is divided into four regions by a first straight line which is parallel to an air outlet and crosses a central axis and a second straight line which is perpendicular to the air outlet and crosses the central axis, and one of the four regions in which a tongue portion is arranged is a first region, followed by a second region, a third region, and a fourth region in this order in a rotation direction of the blades. The air outlet is arranged to extend over both the first and fourth regions.

Abstract: A lower plate includes a lower air inlet arranged radially outward of a bearing portion. In a plan view, a plane is divided into four regions by a first straight line which is parallel to an air outlet and crosses a central axis and a second straight line which is perpendicular to the air outlet and crosses the central axis, and one of the four regions in which a tongue portion is arranged is a first region, followed by a second region, a third region, and a fourth region in this order in a rotation direction of the blades. The air outlet is arranged to extend over both the first and fourth regions.

Abstract: In a blower fan according to a preferred embodiment of the present invention, a side wall portion includes a tongue portion arranged to project between an air outlet and an impeller. A side surface of the tongue portion includes a tongue portion tip arranged to touch a first imaginary plane including a central axis; a first tongue portion side surface arranged to extend from the tongue portion tip along an outer envelope of the impeller; and a second tongue portion side surface arranged to extend from the tongue portion tip toward a side edge, the side edge being a line of intersection of the air outlet and the side wall portion. The second tongue portion side surface is arranged to cross a second imaginary plane including the central axis and touching the side edge.

Abstract: In a blower fan according to a preferred embodiment of the present invention, a side wall portion includes a tongue portion arranged to project between an air outlet and an impeller. A side surface of the tongue portion includes a tongue portion tip arranged to touch a first imaginary plane including a central axis; a first tongue portion side surface arranged to extend from the tongue portion tip along an outer envelope of the impeller; and a second tongue portion side surface arranged to extend from the tongue portion tip toward a side edge, the side edge being a line of intersection of the air outlet and the side wall portion. The second tongue portion side surface is arranged to cross a second imaginary plane including the central axis and touching the side edge.