Impeller in a centrifugal blower
AssigneeNokia Corporation
InventorSeppo J. Leskinen
Life of this patent
Estimating the term…
Abstract
Disclosed is a centrifugal-blower impeller made from a back plate and a front plate and blades attached between these plates. The back plate or the front plate of the impeller or both of them are prestressed in a direction opposite to the stresses produced by centrifugal force when the impeller rotates. According to a preferred embodiment of the impeller the back plate is prestressed by means of a stressing member having the shape of a truncated cone, which is supported by the inner end of the hub of the driving shaft of the blower. In addition a stressing flange is attached to said hub and is tightened to the back plate by means of bolts. The front plate may be prestressed by means of a stressing ring mounted on the suction ring of the front plate.
Claims12
A centrifugal-blower impeller assembly comprising:
- a front plate,
- a back plate spaced from said front plate,
- a plurality of blades extending between and attached to said front and back plates,
- a hub attached to said back plate, and
- means for prestressing said back plate in a direction generally opposite to the stresses produced by centrifugal force when said impeller assembly rotates, whereby said back plate is in an initially prestressed condition prior to impeller operation.
A centrifugal-blower impeller comprising a back plate and a front plate and blades attached between said plates, and prestressing means for prestressing at least one of said back plate and said front plate in a direction generally opposite to the stresses produced by centrifugal force when said impeller rotates, whereby at least one of said back plate and said front plate is in initially prestressed condition prior to impeller operation.
A centrifugal-blower impeller comprising a back plate and a front plate and blades attached between said plates, said back plate and said front plate being prestressed in a direction generally opposite to the stresses produced by centrifugal force when said impeller rotates by prestressing means including a part having the shape of a truncated cone being attached to the inner wall of said impeller back plate and around a hub of a driving shaft of said blower, an end portion of said part being supported by the inner end of said hub, a stressing flange being attached to said hub, the distance of said stressing flange from the inner end of said hub being greater than the distance from the outer wall of said back plate to the inner end of said hub, and said stressing flange being tightened to said back plate by means of bolts.
A centrifugal-blower impeller assembly comprising:
- a front plate,
- a back plate spaced from said front plate,
- a plurality of blades extending between and attached to said front and back plates,
- a hub attached to said back plate, and
- means for prestressing said back plate in a direction generally opposite to the stresses produced by centrifugal force when said impeller assembly rotates wherein said prestressing means include a prestressing part attached to the inner wall of said back plate, said part having a portion supported by said hub, and
- means for urging said hub inwardly of said back plate whereby said prestressing part stresses said back plate in a direction generally opposite to the stresses produced in said back plate by centrifugal force when said impeller assembly rotates.
Dependencies are inferred from the claim text.