Abstract: A motor cooling device including an impeller 2, supported by a rotary shaft 1a of a motor 1, and a fan cover 4, which encases a front portion and a peripheral portion of the impeller 2 and has an air inlet 5 in a front surface and an air outlet 6 in the rear. A constricting flow space S1 is arranged at an exit side of the impeller 2 and defined by a motor end surface 1b, which includes an entrance in the proximity of a rear surface of a vane 3 of the impeller 2 and a circumferential surface expanding radially and diagonally in the rearward direction, and a space formation member 10, which is formed on an inner surface of the fan cover 4.

Abstract: A motor cooling device has an impeller (2) pivotally supported by the rotary shaft (1a) of a motor (1), and a fan cover (4). The fan cover (4) covers the front region and outer peripheral region of the impeller (2) and has an air suction port (5) in the front and an air blow-out port (6) in the rear. The fan cover (4) is provided with a partition member (7) extending from a position more outside than the air suction port (5) to the impeller (2). A cavity (8) is defined between the outer periphery of the partition member (7) and the inner surface of the fan cover (4). The negative pressure due to the cavity effect of eddies produced in the cavity (8) causes the main air current passing through the impeller (2) to be drawn to the front ends of the vanes (3) of the impeller (2), so that aerodynamic characteristics and operation sound characteristics of the impeller (2) are improved.

Abstract: A motor cooling device including an impeller 2, supported by a rotary shaft 1a of a motor 1, and a fan cover 4, which encases a front portion and a peripheral portion of the impeller 2 and has an air inlet 5 in a front surface and an air outlet 6 in the rear. A constricting flow space S1 is arranged at an exit side of the impeller 2 and defined by a motor end surface 1b, which includes an entrance in the proximity of a rear surface of a vane 3 of the impeller 2 and a circumferential surface expanding radially and diagonally in the rearward direction, and a space formation member 10, which is formed on an inner surface of the fan cover 4.

Abstract: A centrifugal blower having a hub (2), to an axis section of which a rotating shaft (4a) of a motor (4) is connected, and a blade wheel (1) provided with blades (3) that are stood on the outer periphery of the hub (2) at predetermined spacings in a circumferential direction and whose front edge (3a) is inclined forward in a rotation direction, wherein a bellmouth (5) having an air suction opening (6) is provided on the air suction side of the blade wheel (1). A circulation flow f2 is formed, in which the flow flows from the blowout side of the blade wheel (1) through the rear side of the air suction opening (6) in the bellmouth (5) to the blade wheel (1) into which the flow is sucked again.