Spindle bearing assembly for turbine ventilator

A wind powered turbine ventilator is disclosed in which a turbine head is rotatably supported about a tubular base through which air flow is to be induced. For supporting the head for rotation, there is provided a sleeved ball bearing housing coaxially secured in a bidirectional interlock to a relatively stationary mounting plate and through which an axial spindle extends. Also disclosed is a subassembly of the bearing housing secured to the mounting plate in the bidirectional interlock.

FIELD OF THE INVENTION 
This invention relates to bearing structures, and in particular to a 
bearing lock assembly for supporting the spindle of a wind powered turbine 
ventilator and bearing structures therefor. 
BACKGROUND OF THE INVENTION 
Turbine ventilators are widely used for under-roof ventilation in domestic, 
commercial and industrial applications. Their popularity stems largely 
from a relatively modest purchase cost coupled with a substantial absence 
of any operating cost and ability to operate without regulation. That is, 
the primary purpose of the turbine ventilator is to exhaust under-roof 
accumulation of hot air either internally generated or as a result of sun 
load on the roof. For that purpose, a precise quantity of air flow need 
not be maintained continuously but can instead be permitted to fluctuate 
within a wide range. 
Being wind powered, capacity fulfillment of the turbine ventilator to 
induce a forced air flow upward through a roof opening is dependent upon 
and will fluctuate extensively in correlation to ambient wind velocity. 
Continuous exposure to varying wind and rotational forces subjects the 
ventilator and its bearing supports to severe vibration and wear. 
DESCRIPTION OF THE PRIOR ART 
Wind powered turbine ventilators are available in various sizes affording a 
rated flow capacity at a given wind velocity. Their construction usually 
includes a vaned head mounted for rotation relative to a stationary base. 
The base is adapted to be secured to a roof over an opening provided 
therein in communication with the space to be ventilated. Exterior bracing 
may be provided to aid in securing the components relative to each other 
while an axially depending internal spindle in cooperation with a 
stationary sleeve provides a journalled support for rotation. 
It is desirable in such constructions to minimize resistance to rotation 
since any reduction in rotational velocity at a given wind velocity 
decreases the ability of the turbine ventilator to perform at its rated 
capacity. Upper and lower bearings at each end of the spindle are used in 
most turbines to reduce such resistance. Wind loading has in some 
instances caused the spindle bearings to become unseated or loosen, which 
increases frictional drag forces and may cause uneven bearing wear. Such 
structural failure frequently results in the entire ventilator unit being 
discarded and replaced. 
Exemplifying turbine ventilators of the prior art are the disclosures of 
U.S. Pat. Nos. 3,392,659 and 3,590,720. Exemplifying specific support 
structures for a variety of interlocking items are the disclosures of U.S. 
Pat. Nos. 3,179,367; 4,441,347; and 4,653,708. 
OBJECTS OF THE INVENTION 
It is a general object of the invention to provide an improved wind 
actuated turbine ventilator structure for effecting under-roof 
ventilation. 
A related object of the invention to provide a bearing housing lock for a 
turbine ventilator having improved operational reliability and a 
significantly extended operational life expectancy as compared to bearing 
constructions in turbine ventilators of the prior art. 
Yet another object of the invention to provide an improved bearing housing 
assembly for a turbine ventilator that can better withstand vibrational 
effects while permanently retaining its secured relation with respect to a 
spindle with which it cooperates. 
SUMMARY OF THE INVENTION 
The foregoing objects are achieved in accordance with the invention by 
means of a bearing housing lock and an annular mounting plate 
concentrically supported internally within a turbine head. An aperture in 
the mounting plate is centered between a plurality of L-shaped arcuate 
slots in which a self-contained ball bearing housing can be secured 
thereto in a bidirectional interlock. The bearing housing is adapted, when 
mounted, to be positioned coaxially with the center aperture and includes 
an inner race having a central opening through which a stationary 
depending spindle extends. 
For attachment to the mounting plate, the housing includes a plurality of 
arcuately spaced integral projection tabs that cooperate with the slots 
and with each other to both interlock with and oppositely grip the 
mounting plate forcibly therebetween. The projection tabs each include an 
arcuate resilient arm terminating at its distal end in a depending pad and 
a separate downward and radially extending foot arcuately spaced from the 
arm. The foot is initially placed through the oversized slot opening while 
the pad engages the top surface of the plate. By relative rotation, the 
foot enters the narrow portion of the L-slot for engaging the underside of 
the plate until the pad snaps into the larger opening of the L-slot 
against an opposite edge, to effect the bidirectional interlock and 
prevent a reverse rotation. 
Because the undersurface of the pad in its normal unmounted state extends 
to a plane slightly offset from the upper surface plane of the foot in 
combination with the resilient feature of the arm tab, the arm in 
cooperation with the foot tab on the underside of the plate imposes a 
gripping detent engagement of the mounting plate therebetween. The 
bidirectional interlock and gripping action secures the bearing housing 
within its aligned, spindle seated position. 
The above noted features and advantages of the invention as well as other 
superior aspects thereof will be further appreciated by those skilled in 
the art upon reading the detailed description which follows in conjunction 
with the drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
In the description which follows, like parts are marked throughout the 
specification and drawings with the same reference numerals, respectively. 
The drawing figures are not necessarily to scale and the proportions of 
certain parts have been exaggerated for purposes of clarity. 
Referring now to the drawings, a turbine ventilator 10 has a vaned turbine 
rotor head 12 adapted to be rotated about an adjustably sectioned tubular 
base 14. The base includes a flange 16 extending about its lower end by 
which it ca be secured and flashed over an apertured roof area. The 
underside of turbine head 12 includes an annular collar 18 concentrically 
extending about the upper distal end of base 14. 
For supporting the turbine head for rotation, there is provided internally 
of the head a stationary coaxial spindle 20 secured in bore 30 formed 
between three guide arms 32A, 32B, 32C. At the upper end of the head the 
spindle extends through a crown bearing (not shown). The lower end of 
spindle 20 includes a reduced diameter shank 26 that extends through 
bearing assembly 28 hereof, as will be described, and is received in bore 
30 of the centering guide arms 32A, 32B and 32C. The latter includes 
flanges 34 attachable to the interior wall surface of base 14. 
Providing support for bearing assembly 28 in the foregoing relation is a 
relatively rigid, horizontally placed, mounting plate 36 adapted to be 
rotated with the turbine head 12. The mounting plate 36 includes a central 
aperture 38 (FIG. 7) and angularly spaced bosses 40. The bosses are 
adapted each to receive a rigid brace 42 secured via a fastener 43 (FIG. 
2) in aperture 41 and extending radially inward from where secured to the 
inner surface of head collar 18. Also provided in mounting plate 36 are 
three arcuately spaced apart L-shaped slots 44 by which the bearing 
housing 28 is secured thereto. Defining each slot 44 is a larger portion 
45 extending from an edge 47 and merging with the narrower portion 49 
extending to an edge 51. 
Bearing assembly 28, as will now be described with reference to FIGS. 3-6, 
includes ball bearings 46 secured between an inner race 48 and an outer 
race 50. Upper and lower flanges 52 and 54 respectively enclose the 
bearing cavity while annular Teflon.RTM. seals 56 and 58 cooperate with 
the flanges for preventing entry of dust particles. Centrally extending 
through the inner race 48 is a sleeve opening 60 in which lower shank 26 
of spindle 20 is received. 
For mounting the bearing housing securely onto mounting plate 36, there are 
provided three projection tabs 62 and three flange tabs 64 which project 
outwardly from outer race 50. Each projection tab 62 has an arcuate arm 66 
radially joined at 67 to the exterior of race 50 coplanar with its 
undersurface. At its distal end, arm 66 includes a downwardly depending 
pad 68 (FIG. 3). Each flange tab 64 is integrally formed at 72 with the 
undersurface of housing 50 and has a radial offset foot 70 adapted to be 
inserted through the larger opening 45 of the plate slot 44. 
The foot 70 includes an upper surface 74 adapted when bearing installation 
is completed to forcibly engage the undersurface of the mounting plate 36. 
To effect gripping action, the undersurface of arm 66, when the bearing 
housing is in its unmounted state as illustrated in FIG. 3, is in a plane 
approximately the same as the plane of the upper surface 74 of foot 70. At 
the same time, arm 66 by virtue of its cantilevered arrangement affords 
some degree of resilience about its hinged union at 67. 
To install the bearing housing 28 onto plate 36, each foot tab 70 is first 
inserted through the larger opening 45 of a corresponding plate slot 44. 
Once all the foot tabs are inserted, the mounting plate 36 and bearing 
assembly 28 are relatively rotated in a bayonet lock as the depending 
portion 72 of foot 70 enters the narrow portion 49 of the slots 44. In the 
course of placing foot tab 70 through opening 45, the arm pad 68 of tab 62 
is biased upwardly into a forced engagement against the upper surface of 
the mounting plate. During the rotational locking step, foot portion 72 is 
advanced until it engages edge 51 at which time biased pad 68 descends 
into opening 45 adjacent edge 47. This imposes a firm, bidirectional 
interlock against further rotation in either direction. At that time the 
biasing effect of arm 66 draws foot surface 74 into engagement against the 
undersurface of the mounting plate 36. By virtue of the three 
bidirectional interlocks and biasing effects of the pads, the pad 68 and 
foot 70 cooperate to grip mounting plate 36. 
Prior to the bearing housing and mounting plate being secured in the 
relationships of FIGS. 1 and 2, the lower spindle shank 26 is positioned 
so as to extend rotationally secured in bearing sleeve 60 with its distal 
end secured in guide bore 30. 
Upon completion of the foregoing assembly, head 12 is supported for 
rotation via stationary spindle 20 extending through bearing unit 28. The 
ball bearing assembly 28 provides considerably greater ease of rotation 
than a similarly placed journal bearing. Because it is secured by the 
bidirectional interlock, vibration and side loading forces are reacted 
without unseating the bearing assembly. Capacity performance of the 
ventilator is therefore increasingly maximized, and the life expectancy of 
the bearing support is extended considerably as compared to the journal 
bearings of the prior art. While it is anticipated that the bearing 
assembly of the present invention will last the expected life time of the 
ventilator, the bearing housing via its connections to the mounting plate 
can nonetheless be forcibly removed from the mounting plate for 
replacement when necessary 
By the above description, there is disclosed a wind powered turbine 
ventilator having an improved bearing interlock structure for securing the 
bearing assembly against the adverse effects of vibration. For effecting 
the interlock, the bearing assembly includes three arcuately spaced 
projection tabspaired with three flange tabs that interfit with L-shaped 
slots in a mounting plate to effect a bidirectional interlock. 
Each projection tab has a resiliently biased arcuate arm integrally 
extending from the bearing housing and terminating in a depending pad. 
When assembled, the flange tab extends through the narrow opening of the 
L-slot engaging the terminal edge of the slot with the upper surface of 
the flange tab engaging the undersurface of the mounting plate. At the 
same time, the pad on the arm end of the projection tab 62 penetrates 
inwardly of the larger opening of the slot engaging the opposite terminal 
edge while the undersurface of the arm is biased against the upper surface 
of the mounting plate. 
The opposite edge engagements of the respective tabs prevent any 
bidirectional rotation between the bearing assembly and the mounting plate 
while their respective surface engagements cooperate to effect a resilient 
gripping of the intervening plate. The virtues of this construction in the 
extended operating life of the ventilator that it affords should be 
readily appreciated by those skilled in the art. 
Since many changes could be made in the above construction and many 
apparently widely different embodiments of this invention could be made 
without departing from the scope thereof, it is intended that all matter 
contained in the drawings and specification shall be interpreted as 
illustrative and not in a limiting sense.