Adjusting mechanism for variable inlet vane

A variable inlet vane adjusting construction including a plurality of vanes pivotally mounted about a hub, an adjusting ring circumferentially slidable on the hub, a plurality of circumferentially spaced axial slots on the adjusting ring, a bearing of substantially solid rectangular configuration in each of the slots and in engagement with the sides of the slots, a plurality of pin members each having first and second ends with the first ends being mounted for universal movement on each of said bearings and the second ends fixedly mounted on levers which are in turn fixedly secured to the vanes.

BACKGROUND OF THE INVENTION 
The present invention relates to an improved construction for adjusting the 
position of variable inlet vanes of fans or the like. 
By way of background, there are numerous types of adjusting mechanisms 
which are used. However, these adjusting mechanisms have various 
deficiencies. In this respect, certain prior art mechanisms included 
linkages which were extremely complex. Others utilized gear ring 
constructions which developed looseness in use. Yet others utilized a 
point or line contact between relatively movable linkage members, which 
resulted in wear at the points of contact with attendant undesirable 
looseness between the parts. Prior art adjustment mechanisms are 
characterized by U.S. Pat. Nos. 2,606,713, 2,923,495, 3,074,689, 
3,289,919, 3,352,537 and 3,392,958. It is with the overcoming of the 
deficiencies of prior art constructions that the present invention is 
concerned. 
SUMMARY OF THE INVENTION 
It is accordingly the object of the present invention to provide an 
improved variable inlet vane adjusting construction which is extremely 
simple and which will wear well in use so that large amounts of play 
between relatively movable parts of the adjusting construction is not 
experienced. 
Another object of the present invention is to provide a variable inlet vane 
adjusting construction which is easy to repair and easy to assemble. Other 
objects and attendant advantages of the present invention will readily be 
perceived hereafter. 
The improved variable inlet vane adjusting construction of the present 
invention comprises a hub, a vane having an axis mounted at an acute angle 
to the axis of said hub, first pivot means mounting said vane for pivotal 
movement on said hub, an adjusting ring, means mounting said adjusting 
ring for circumferential sliding movement on said hub about the axis of 
said hub, a plurality of spaced axial slots on said adjusting ring, first 
opposed sides on said slots, a bearing of substantially solid rectangular 
configuration in each of said axial slots, each of said bearings having 
opposite second sides in face-to-face slidable engagement with said first 
sides, a plurality of pin members each having first and second end 
portions, second pivot means pivotally mounting said first end portion of 
each pin member on a bearing for movement relative to said bearing in 
three planes, a plurality of levers having first and second ends, means 
for fixedly attaching said first end of each of said levers to a vane, and 
means for fixedly attaching said second ends of each of said levers to a 
second end of each of said pins whereby rotation of said adjusting ring 
causes pivotal movement of said vanes while said first and second sides 
remain in full face-to-face engagement. The present invention will be more 
fully understood when the following portions of the specification are read 
in conjunction with the accompanying drawings wherein:

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The improved vane adjusting construction of the present invention is used 
to adjust the position of vanes 10 mounted for pivotal movement within an 
inlet bell 11 associated with a fan (not shown) mounted on shaft 12, as is 
well known in the art. Each of vanes 10 has an adjusting mechanism 13 
(FIG. 5) associated therewith. The structure of each vane 10 includes 
sheet metal sides 14 and 15 which are secured to central tube 16, which in 
turn is pivotally mounted on shaft 17, the upper end of which is fixedly 
secured to inlet bell housing 19, as shown in FIG. 2, and the lower end 20 
of which is threaded into annular fan hub 21, as shown in FIG. 3. The axis 
of shaft 17 extends at an acute angle to the axis of hub 21. The specific 
details of the mounting structures for the opposite ends of shaft 17 form 
no part of the present invention and accordingly a detailed description 
thereof will not be made. It is only necessary to understand that shaft 17 
is fixedly secured between shell 19 and annular hub 21. The upper end of 
tubular member 16 is mounted on bearing 22 on shaft 17 and the lower end 
is mounted on bearing 23 on shaft 17. 
The adjusting structure 13 includes an annular adjusting ring 24 having an 
inner portion 25 which is received in annular groove 26 formed between 
annular hub portion 21 and annular hub portion 27 which is secured thereto 
by a plurality of circumferentially spaced bolts 29. By virtue of the 
foregoing connection, adjusting ring 24 can slide circumferentially in 
groove 26. The hub 21 is suitably attached to annular housing portion 30 
which is an extension of duct portion 31. A plurality of axial slots 32 
(FIG. 6) are circumferentially spaced about the outer periphery of 
adjusting ring 24. A rectangular bearing 33 has its opposite sides 34 in 
sliding engagement with the opposite sides 35 of slot 32. A pin 36 has one 
end press-fitted into spherical bearing 37 which is journalled in race 39 
which in turn is held within bearing 33 by snap ring 40. Because of this 
connection, bearing 37 can swivel in all directions within its race 39, as 
governed by the geometry of the structure. The upper end 41 (FIG. 5) of 
pin 36 is press-fitted within bore 42 of lever 43 and is fixedly fastened 
therein by means of screw 44, as shown in FIG. 5. The opposite end of 
lever 43 has a clamping collar 45 associated therewith which consists of 
lower collar portion 45' and upper collar portion 45", each of which fit 
in complementary mating relationship with tube 16. Collar portion 45' is 
welded to tube 16, and diametrically spaced screws 46 releasably tighten 
clamping collar portion 45" to portion 45'. Lever 43 is an integral 
extension of collar portion 45". 
Whenever it is desired to simultaneously adjust the position of vanes 10, 
adjusting ring 24 is slid circumferentially in groove 26 by moving link 49 
in the direction of arrows 50. Link 49 is mounted on pin 51 (FIG. 5) which 
straddles bifurcated end 52 of link 53 which is attached to adjusting ring 
24 by means of bolts 54. The movement of adjusting ring 24 in a 
circumferential direction will cause bearings 33 to slide in a generally 
axial direction in slots 32. At the same time, the circumferential 
movement of adjusting ring 24 will be transmitted through pins 36 to 
levers 43 which in turn will cause pivotal movement of vanes 10 about the 
axes of shafts 17, which in turn will move vanes 10 between their open and 
closed limits, as shown in FIGS. 4 and 8. The spherical bearing 37 permits 
the foregoing action to take place in view of the fact that there is a 
universal fit between bearing 37 and its race 39 which permits pin 36 to 
assume any required pivotal position relative to bearing 33. Furthermore, 
it is to be noted that there is a space 55 (FIG. 5) between the bottom 
surface 56 of rectangular solid bearing 33 and the bottom wall 57 of slot 
32. This clearance prevents binding between the bottom surface of the 
bearing and the bottom wall of the slot, inasmuch as the space between 
these two portions vary with the circumferential position of adjusting 
ring 24. 
As can be seen, the bottom wall 57 is inclined to the horizontal at 
approximately 10.degree.. This is essentially the angle at which the 
bottom surface 56 of bearing 33 will track during pivotal movement of 
adjusting ring 24. Therefore, the space 55 will tend to remain 
substantially constant, although it does vary with the circumferential 
position of adjusting ring 24. 
The square bearing 33 carrying the spherical bearing 37 provides a truly 
universal fit between pin 36 and adjusting ring 24, thereby obviating any 
binding which might otherwise be experienced during adjustment. In this 
respect, bearing 37 permits pivotal movement of pin 36 in three planes, 
namely, the X, Y and Z planes. In addition, the parallel sides 34 of 
bearing 33 have full surface contact with the parallel sides 35 of slots 
32, thereby avoiding the line or point contact of previous constructions 
and thus prolonging the life of the bearings. Furthermore, bearing 33 is 
of the self-lubricating variety which does not require frequent 
lubrication. The bearing 33 has been described as being of rectangular 
solid configuration, but more specifically it is square in plan. 
Therefore, after two sides 34 have been worn in use, the bearing can be 
rotated 90.degree. about the axis of pin 36 and sides 34' can be placed in 
engagement with slot sides 32. It is to be especially noted that there is 
always full face-to-face engagement between bearing sides 34 and slot 
sides 32 in all positions of the vanes. Thus, there is almost no tendency 
for the connection between these faces to become loose, which in turn, 
could cause the vanes 10 to flutter. 
It can thus be seen that a good solid connection is provided for adjusting 
the vanes and the tendency of the parts to wear very little results in 
accurate adjustment of the vanes. Furthermore, because of the simplicity 
of the structure, there is the advantage of great ease of replacement of 
parts and ease of overall maintenance. 
While a preferred embodiment of the present invention has been disclosed, 
it will be appreciated that the present invention is not limited thereto, 
but may be otherwise embodied within the scope of the following claims.