Abstract An impeller wheel for an axial flow fan with adjustable vanes. Each vane comprises a pin which is rotatably accommodated in the hub rim of the wheel and within the said rim carries an adjustment arm which via a link rod is connected to an adjustment member which is common to all the vanes and is displaceable in the axial direction of the wheel, but is coupled to the wheel for rotation together with the latter. At one end the link rod is connected to the adjustment arm by means of a radial bearing and at its other end is connected to the adjustment member likewise by means of a radial bearing. At least one of these bearings consists of two parts, one of which has a sliding surface in the form of a hemispherical belt or a semi ball belt which slides in the other part which has the form of a cup with a corresponding sliding surface. In connection with one of these bearing parts a member is provided to prevent the parts from falling apart during standstill periods of the fan, and the link arm possesses a mass of such an order of magnitude that the centrifugal force on the arm occurring during the operation of the wheel is sufficient for keeping the two parts pressed against each other even when the highest possible adjustment force is being applied.
An impeller wheel for an axial flow fan with adjustable vanes, where each vane has a pin which is rotatably accommodated in the hub rim of the fan wheel and within the said rim has an adjustment arm and an adjustment member for adjusting the pitch of the vanes which is common to all the vanes and is displaceable in the axial direction of the fan wheel, but is coupled to the wheel for rotation together with the latter; the improvements comprising: a. a link rod connecting each adjustment arm with the adjustment member such that axial movement of said adjustment member changes the pitch of the adjustable vanes; and b. two piece hemispherical bearing means interposed between said link rod and said adjustment member, and between said link rod and said adjustment arm oriented such that the centrifugal force generated by rotation of the impeller wheel acting on the link rod retains the bearing pieces in contact with each other even when the highest possible adjustment force is being applied.
Claim 2
Dependent Claim
171 words
An impeller wheel for an axial flow fan with adjustable vanes, where each vane has a pin which is rotatably accommodated in the hub rim of the fan wheel and within the said rim has an adjustment arm and an adjustment member for adjusting the pitch of the vanes which is common to all the vanes and is displaceable in the axial direction of the fan wheel, but is coupled to the wheel for rotation together with the latter; the improvements comprising: a. a link rod connecting each adjustment arm with the adjustment member such that axial movement of said adjustment member changes the pitch of the adjustable vanes; and b. two piece hemispherical bearing means interposed between said link rod and said adjustment member, and between said link rod and said adjustment arm oriented such that the centrifugal force generated by rotation of the impeller wheel acting on the link rod retains the bearing pieces in contact with each other even when the highest possible adjustment force is being applied.
Claim 3
Dependent Claim
104 words
The impeller wheel of claim 1 wherein the bearing means comprises: a. a first hemispherical bearing attached to said adjustment member; b. a first bearing attached to a first end of said link rod, said first bearing having a hemispherical cavity therein, the surface of said hemispherical cavity slidingly engaging the surface of said first hemispherical bearing; c. a second hemispherical bearing attached to said adjustment arm; and d. a second bearing attached to a second end of said link rod, said second bearing having a hemispherical cavity therein, the surface of said hemispherical cavity slidingly engaging the surface of said second hemispherical bearing.
Claim 4
Dependent Claim
58 words
The impeller wheel of claim 2 wherein spring means are interposed between said adjustment member and said first bearing, and between said adjustment Arm and said second bearing so as to maintain engagement between said first bearing and said first hemispherical bearing, and between said second bearing and said second hemispherical bearing when said impeller wheel is stationary.
Claim 5
Dependent Claim
20 words
The impeller wheel of claim 2 wherein the hemispherical surface of the first and second hemispherical bearings face radially inwardly.