Abstract: A pipeline includes a pipeline body in which fluid flows and a throttle formed at a specific position of the pipeline body as a flow passage sectional shape of the pipeline body is changed from that of a remaining portion of the pipeline body. The specific position at which the throttle is provided is a position in the pipeline body and corresponds to a position that serves as an abdominal part of the pipeline in a vibration mode where a resonance frequency is the closest to a pulsation frequency of pressure pulsation caused by the fluid.

Abstract: An electric blower includes a fan, an electric motor, a motor holder, and a fan casing. The fan casing includes a facing wall and the motor holder includes an extending portion overlapping with the facing wall in an axial direction. The facing wall and the extending portion include attachment portions that connect the motor holder to the fan casing and non-attachment portions between the attachment portions. Either one of the facing portion and the extending portion includes an annular protrusion. The other includes an annular fitting recess into which the annular protrusion is fit. A contacting load is defined by a load applied to the annular protrusion and the annular fitting recess in the axial direction or an intersecting direction intersecting the axial direction. At least one of the non-attachment portions receives the contacting load that is greater than the contacting load applied to each of the attachment portions.

Abstract: A pipeline includes a pipeline body in which fluid flows and a throttle formed at a specific position of the pipeline body as a flow passage sectional shape of the pipeline body is changed from that of a remaining portion of the pipeline body. The specific position at which the throttle is provided is a position in the pipeline body and corresponds to a position that serves as an abdominal part of the pipeline in a vibration mode where a resonance frequency is the closest to a pulsation frequency of pressure pulsation caused by the fluid.