Adaptor with improved airflow

Abstract

An adaptor is disclosed for connecting a rotating electrical machine 12 to a prime mover 10 . The adaptor comprises at least one air outlet. The adaptor is arranged to provide an increase in a cross-sectional area of air flow towards the outlet. In this way part of the dynamic pressure can be converted into additional static pressure rise through steady expansion of the air flow cross-section. This in turn may help to improve the overall amount of cooling air passing through the machine for a given fan input power.

1 - 38 . (canceled) 
     
     
         39 . An adaptor arranged to connect a rotating electrical machine to a prime mover, the adaptor comprising an air outlet, wherein the adaptor is arranged to provide an increase in a cross-sectional area of air flow towards the air outlet. 
     
     
         40 . An adaptor according to  claim 39 , wherein the adaptor comprises a wall which directs air flow along an airflow path with an increasing cross-sectional area. 
     
     
         41 . An adaptor according to  claim 40 , wherein the wall functions as a partial volute. 
     
     
         42 . An adaptor according to  claim 40 , wherein the wall is arranged to reduce re-entrainment of air back into the adaptor. 
     
     
         43 . An adaptor according to  claim 39 , wherein the adaptor is arranged to house a fan. 
     
     
         44 . An adaptor according to  claim 43 , wherein the increase in the cross-sectional area of the air flow is achieved by virtue of an increasing distance between a perimeter of the fan and a wall of the adaptor. 
     
     
         45 . An adaptor according to  claim 39 , wherein the increase in the cross-sectional area of the air flow is progressive. 
     
     
         46 . An adaptor according to  claim 39 , wherein the adaptor is substantially square-shaped in axial cross section. 
     
     
         47 . An adaptor according to  claim 39 , wherein the adaptor comprises a plurality of air outlets, and the adaptor is arranged to provide an increase in a cross-sectional area of air flow towards each air outlet. 
     
     
         48 . An adaptor according to  claim 47 , wherein the air outlets are spaced apart around the circumference of the adaptor. 
     
     
         49 . An adaptor according to  claim 48 , wherein the adaptor has four quadrants and an air outlet is provided in each of the four quadrants. 
     
     
         50 . An adaptor according to  claim 39 , wherein the adaptor comprises a front member arranged to connect the adaptor to the prime mover and a rear member arranged to connect the adaptor to the electrical machine. 
     
     
         51 . An adaptor according to  claim 50 , wherein the adaptor comprises at least one wall connected between the front member and the rear member, and the wall is arranged to direct air flow along an airflow path with an increasing cross-sectional area. 
     
     
         52 . An adaptor according to  claim 51 , wherein the air outlet is provided in a first part of the wall, in the direction of air flow, and a second part of the wall is without an air outlet or has an air outlet which is blocked off. 
     
     
         53 . An adaptor according to  claim 52 , wherein the second part of the wall functions as a partial volute and/or to reduce re-entrainment of air back into the adaptor. 
     
     
         54 . An adaptor according to  claim 39 , further comprising a cowling for directing airflow around at least part of the outside of the adaptor, wherein the cowling is arranged to direct airflow which exits from the top or bottom of the adaptor towards a side of the adaptor. 
     
     
         55 . An adaptor according to  claim 39 , the adaptor comprising an adaptor core and a removable cover, wherein the removable cover defines the air outlet. 
     
     
         56 . An adaptor according to  claim 55 , wherein the removable cover is arranged to fit over an aperture in the adaptor core. 
     
     
         57 . A rotating electrical machine comprising:
 an adaptor arranged to connect the machine to a prime mover; and   a fan arranged to draw air though the machine,   wherein the fan is housed in the adaptor,   the adaptor comprises an air outlet, and   the adaptor comprises a wall which provides an increase in a cross-sectional area of air flow from the fan towards the air outlet.   
     
     
         58 . A method of cooling a rotating electrical machine, the rotating electrical machine including an adaptor which connects the machine to a prime mover, the adaptor comprising at least one air outlet, the method comprising drawing air flow through the machine and out through the at least one air outlet, wherein a cross-sectional area of the air flow increases towards the or each air outlet.