Centrifugal blower unit

#This application is based on Japanese Patent Application No. 2002-106518 filed on Apr. 9, 2002, the disclosure of which is incorporated herein by reference.

#The present invention relates to a centrifugal blower unit used for an inside and outside air double-layered flow type vehicular air conditioner, which sucks inside and outside air separately at the same time.

#JP-A-2000-203235 discloses a centrifugal blower unit for an inside and outside air double-layered flow type vehicular air conditioner. In the centrifugal blower unit, a divider is provided to restrict mixture of two kinds of air blown by a centrifugal fan.

#Other objects, features and advantages of the present invention will become more apparent from the following detailed description made with reference to the accompanying drawings, in which like parts are designated by like reference numbers and in which:

#FIG. 1 is a schematic cross-sectional view of a centrifugal blower unit according to the first embodiment of the present invention;

#FIG. 2 is a cross-sectional view of a part of a centrifugal blower unit according to the second embodiment of the present invention;

#Referring to FIG. 1, a centrifugal blower unit 1 is used for an inside and outside air double-layered flow type vehicular air conditioner that draws inside air and outside air separately at the same time. An air conditioner casing (not shown) is connected to an air downstream position of the centrifugal blower unit 1. Devices for conditioning air temperature, such as an evaporator, heater core and air mixing doors, are provided in the air conditioner casing.

#The centrifugal blower unit 1 is integrated with an inside and outside air switching unit 40 (described later) by a mechanical fastening device such as bolts and screws. In FIG. 1, an electric motor 10 is a driving device for rotating a centrifugal fan 20. The centrifugal fan 20 is an impeller including a first fan 20a and a second fan 20b. The first fan 20a includes a plurality of first blades 21 arranged about a rotation axis CL. The first fan 20a draws air in an axial direction and blows it in a radially outside direction. The second fan 20b includes a plurality of second blades 22 arranged about the rotation axis CL at a position offset from the first blades 21 in a direction parallel to the rotation axis CL. The second fan 20b draws air in the axial direction and blows it in the radially outside direction.

#The motor 10 is fixed to a scroll casing 30 (described later) through a flange 11 that is provided in an outer periphery of a motor housing. A hub 23 is a main plate and transmits a rotation force of the motor 10 to the second fan 20b. A second side plate 24 is located at ends of the second blades 22 on a side opposite to the hub 23 in the axial direction. The second side plate 24 transmits the rotation force transmitted to the second fan 20b to the first fan 20a. The second side plate 24 is formed into an annular plate. The second side plate 24 reinforces the second fan 20b as a reinforcement member.