| 摘要 |
1,151,001. Centrifugal blowers. ROTRON MFG. CO. Inc. Jan. 4, 1967 [Feb. 2, 1966], No. 468/67. Heading F1C. [Also in Division H2] - In a centrifugal blower the volute casing 14, fabricated from polyester resin, has a substantially elliptical cross-section, and the ratio of the cross-section axis 20a to the cross-section axis 20b progressively increases around the casing in the direction of impeller rotation to provide optimum flow characteristics at all positions. As shown, the ratio is greater than 1 at the discharge. The cut-off 18a is inclined relative to the impeller blades 10a to reduce noise. The stator windings 21a and parts of the rotor 22 of the electric driving motor are cooled by exposure to the air circulating in the casing. Moreover, heat is conducted from the rotor through a hub 27, as of aluminium, to the impeller which acts as a heat sink. The motor housing has inner and outer portions 30, 31a with a cavity 50 therebetween which houses electrical elements, such as starting capacitor 51, switches or overload relays. The blower may be mounted to a plate or wall by flange 48 at its discharge, or to a support by bolts engaging tapped holes 36 or tapped holes (not shown) in the left-hand end of motor housing portion 30. The blower casing and motor housing are connected together by clamps each formed by a block 40 having an inclined surface 40c engaging a plane surface on a rib 42. Tightening of screws 44 secures an annular shoulder 34 in a circumferential groove 32. The blower casing can be angularly adjusted relative to the motor housing to vary the direction of discharge. |
