Abstract: A peripheral toroidal blower has a stripper consisting of a central block part and two curved vanes projecting one from each end of the block part and extending in opposite directions around the toroidal chambers to at least partially cover the inlet and outlet ports. The active surfaces of the stripper are of porous material whereby to provide a substantial reduction in blade passing frequency noises. The active surfaces may be of inherently porous material such as polyurethane foam or of a nominally closed cell plastics foam of which the active surfaces are made porous by machining or cutting.

Abstract: A lubricated bearing has a rotatable structure which includes a housing with an opening at one end, a bearing cup and a retaining member. The retaining member grips the exterior of the bearing cup and the interior of the housing to secure the bearing cup within the housing with its mouth towards the opening and with lubricant spaces between the housing and bearing cup both above and below its rim. A stationary member has a spherical part which fits within the bearing cup to provide relatively rotatable bearing surfaces and a shaft which extends out of the housing through the opening.