Abstract: It has been discovered that by eliminating the cutoff in a centrifugal blower the tone or whistle-like noise usually produced by such blower may be eliminated without unreasonably affecting the performance of the centrifugal blower and in many instances without having any significant effect on such performance. Briefly, the invention is directed to a centrifugal blower and to a particular type of blower housing therefor, in which there is no such cutoff or like impediment to provide the allegedly required transition in the involute wall portion of the blower relatively proximate the blower outlet.

Abstract: The present invention is directed to an improved blower system particularly useful for vehicles wherein the one or more fans, squirrel cage blowers or the like are driven by a hydraulic motor which is powered directly from the hydraulic system of the vehicle. Thus, the blower system of the present invention may draw on such hydraulic power without presenting any substantial drain on the hydraulic system or on the vehicle engine. For equal physical size motors, the hydraulic motor typically has an increased output capacity over conventional DC electric motors previously employed in such blower systems. Moreover, the hydraulic motor is continuously lubricated by hydraulic fluid flowing therethrough so that there is minimal wearing of the parts thereof with the end result that the life expectancy will ordinarily equal or exceed that normally expected for a typical vehicle.