| 摘要 |
<p>In a device (31) for metering the volume flow of a gaseous medium with a fan (33) arranged in a housing (32), the metering member connected upstream of the fan is designed as a metering drum (41) which is provided with a servomotor (43), mounted rotatably in a housing (42) equipped with a suction duct (48), and has a control opening (45) which extends in the circumferential direction and is delimited by one or more control cams (46). By means of this design, it is possible to shape the cross-section of the control opening (45), which can be flowed through, in such a manner that, depending upon the adjustment travel of the metering drum (41), a proportional change in quantity of the medium flowing through it is brought about. The volume flow of the medium can consequently be adjusted very accurately. Moreover, the flow resistances to be overcome are low and noise development is counteracted. <IMAGE></p> |
