Note: Descriptions are shown in the official language in which they were submitted.
7667
The present invention relates generally to agricultural equipment
and more particularly relates to a self-aligning bearing of the type utilized
for supporting a shaft having earthworking tools, such as disk blades, mounted
thereon.
Rotating earthworking tools such as disk harrow blades are typically
supported for rotation with a shaft which in turn is carried by bearings mounted
in a support suspended from an implement frame.
The bearings which carry the shaft for rotation must be designed not
only to assure that the shaft rotates freely but must also permit, during
earthworking operations, limited oscillation of the bearing outer race within
~- the bearing support.
Oscillation of the bearing outer race within the support can occur as
a consequence of several factors. Generally, several supports carry bearings
within which a shaft is mounted. The bearing supports are in turn carried by
the implement frame. During assembly of the shaft bearings and supports, slight
misalignment of the shaft within the bearing can result. Additionally, various
forces are encountered by tools such as disk blades as they work varying soil
conditions and contact objects and obstacles in the ground. These forces create
axial as well as radial loadings upon the shaft and bearings and require that
the bearing be able to oscillate axially within its support but realign subse-
quent to exposure to the forces. Further, the frame from which the bearing
,, supports are suspended is subjected to vertical and horizontal loadings, thereby
transferring to the bearing supports axial and radial forces and further
requiring that the bearing be designed to absorb axial loadings and be able to
shift or oscillate slightly during exposure to the forces.
During operation, the disk blades, shaft, bearings and bearing
supports are exposed to dirt, sand, water and other bearing contaminates. To
prevent the entry of such contaminates into bearings as they rotate and
'`'
- .. .. .
. .
': - , ~.: : . . , , :
L~: . . ' . . ' .,, : . .
" . - : :: : . .
~:;, ... ., . - . . , , .. :'
- 1~8766~7
oscillate and thereby prevent damage to interacting metal surfaces, metal
supports often encase or shroud the bearing and seals. An example of such a
support can be found in U.s. Patent 3,311,429 to Kocian. This type of support,
however, limits the degree of oscillation or wobble of the bearing.
While encasing metal supports protect bearings from most contamination,
they still permit the entry of some contamination through the openings between
the support and the shaft or collars mounted adjacent the bearing. This
contamination then accumulates against the seal surfaces or mixes with the
lubricant between the outer bearing race-ring support and outer race ring outer
surface. Consequently, the interacting metal surfaces become scarred and wear
rapidly, or the bearing seal loses its flexibility and wears rapidly due to the
accumulated dirt packed adjacent to it. As a result, premature bearing failure
occurs.
SUMMARY OF THE INVENTION
-
To overcome these problems, there is provided a self-aligning bearing
which assures free rotation of the shaft within the bearing support and which
accommodates limited oscillating movement or wobble of the shaft and its bearing
; relative to the support. This is provided through the use of spherically-shaped
complementary surfaces between the housing or support and outer race ring. A
~; 20 unique flexible seal configuration prevents contamination from entering between
the spherically-shaped interacting metal surfaces and into the anti-friction
means and prevents the accumulation or packing of dirt adjacent to the seal.
To assure self-alignment during operation, the co-acting spherical
, surfaces of the housing and outer race ring are sized to be freely slidable
h ; against one another even after assembly~ A reservoir of lubrication may be
provided between the housing and outer race ring to assure continued lubrication
and the housing is formed to have side flanges projecting axially well beyond
~ the radially extending faces of the outer race ring to reduce exposure to
- - 2 -
,~: ; ,.
~' ~"
. . . , . .,, - ~.
' ' . ' "': ' ' ' ' .~ - ~ -' " . ' ' ;
,
,: . '
766~
contaminates and increase the range of oscillation permitted. Resilient seals
are carried by the outer race ring and each includes a first lip or lips
extending radially towards and wipingly engaging the inner race ring to seal
the anti-friction ball bearings against contamination. To resist rotating
movement of the outer race ring relative to the housing, the unique seal is
provided with a second and thicker resilient lip which frictionally rubs against
- the spherical support surface of the housing. This lip flexibly acts to
restrict rotating and oscillating movement of the outer race ring relative to
the housing, yet permits such movement wpen the forces exceed certain threshold
limits. A stiffening member preferably extends radially along the radially
extending face of the outer race ring and supports the second lip to assure
sufficient frictional contact between it and the spherical housing surface.
.
When assembled, the spherical surface of the housing compresses the second lip
radially inwardly to further insure the desired frictional contact and restrict
relative movement between the two spherically-shaped surfaces.
To prevent the entry of contamination into the anti-friction ball
bearings, one or more radially inwardly extending lip surfaces are provided to
~: wipingly engage the outer circumferential surface of the inner race ring. The
second or outwardly extending resilient seal lip can further be modified to
engage the collar member adjacent the inner race ring and retard the accumulation
of such contamination next to the wiper lip or lips which seal the anti-friction
means.
To assure a continued supply of lubrication to the interacting
spherical metal surfaces and also the anti-friction means, a lubrication
reservoir and improved means for introducing lubrication into the bearing and
between all interacting metal surfaces is further provided.
:'; '
.' ,~
~ : :
~766~
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a partial view of a disk harrow, illustrating the bearing
and its support in combination with the disk frame, shaft, and blades.
Fig. 2 is an enlarged and cut away side view of the bearing, bearing
support and adjacent spacer collars.
Fig. 3 is a further enlarged and partial view of the bearing and its
seal illustrated in Fig. 2.
Fig. 4 is a view similar to Fig. 3, illustrating a seal construction
utilizing a core.
Fig. 5 is a view similar to Fig. 4 and illustrating another seal and
core construction.
Fig. 6 illustrates yet another alternate seal construction having
separate resilient seal lips.
- Fig. 7 illustrates another alternate seal construction and core
structure for attaching tne seal to the outer race ring.
Fig. 8 illustrates a further modification of the seal construction
! and core structure for attaching it to the outer race ring.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to Fig. 1 of the drawings, there is shown a portion of
a typical disk harrow including a disk frame 10 and disk blades 12 supported on
a shaft 14 which is carried by a bearing support 16. The frame 10 further
. carries a scraper tube 18 connected thereto by ~ bolts 20, 22 and brackets 24.
Self-adjusting scrapers 26 are pivotally carried by tension levers 28 supported
on the scraper tube 18 and biased by tension springs 30 into contact with one
surface of a respective disk blade. The bearing support 16 includes the
structural arm 32 connected by bolts 34 with the frame 10 and to stamped flange
halves 36 and 38 by bolts 40.
~i
~ - 4 -
~'
~, . . . ..
()~766~
Looking now to Fig. 2 which illustrates in cross section the shaft 14,
bearing 46 and adjacent spacer spools 42 and 44, it will be seen that the
bearing 46 is carried within the stamped flange halves 36 and 38. The shaft 14
carries an inner bearing race ring 48 and an outer race ring 50 with a plurality
of anti-friction elements or ball bearings 52 therebetween. The flanges 36 and
38 have an inner bearing-receiving surface 56 shaped in a section of a sphere
and the outer race ring outer surface 54 is formed to complement and be
slidably received by the bearing-receiving surface 56. Normally, the spherical
surfaces are formed about a common center located in the shaft. To assure free
sliding action (oscillation) of the outer race ring 50 in the support 16, the
outer surface of the outer race ring is formed about a smaller radius than the
radius of the inner surface of support housing 16.
Cast spacer spools or collars 42 and 44 are placed on either side of
the bearing in abutment with the sides of the inner race ring 48. The diameter
of the portions of the spacer spools 42 and 44 adjacent the inner race ring 48
in the preferred embodiment exceeds the diameter of the outer surface of the
inner race ring 48.
Fig. 3 illustrates in greater detail the unique configuration of the
seal 58 carried by the outer race ring 50. The resilient annular seal 58
includes first resilient lips 60 extending radially inwardly and a second
resilient lip 62 extending outwardly. Both lips 60 and 62 are integrally formed
and carried by the metal core 64 which is attached to an annular metal cup
support 66 which in turn is carried by the outer race ring 50. The core 64 is
comprised of a first radially extending portion carried at the axial outer face
~, of the outer race ring 50 and a second axially extending portion that is carried
at the inner surface of the outer race ring 50. These core portions respective-
` ly aid in supporting the second and first lips 62 and 60. The first lips 60
of the seal extend radially inwardly and wipingly engage the outer
- 5 -
,` ' ',~ '' -, ' -
~08766 ,~
circumferential surface 68 of the inner race ring 48 as it rotates with the
shaft 14 during field working operations. The second resilient lip or wiper
seal 62 is of a thicker cross section relative to the surfaces of the first lip
and wipingly engages the inner surface 70 of the portion 72 of the wide flanges
36, 38 which extends axially beyond and overhangs the outer edge of the outer
race ring 50.
The lip 62 is formed with a thick cross section so that it can exert
substantial pressure on the spherical surface 70 and serve as a brake or drag
to resist relative movement between the-outer race ring 50 and housing 16
and also as a seal against contaminates entering between the ring 50 and housing
16. Lips 62, as well as lips 60, are formed so that when assembled they are
deflected so that a better frictional engagement is realized. Also aiding to
support the lip 62 is the radially extending portion of the core 64. The lip 62
further includes a broadened outer surface that increases the contact area
between it and the surface 70. Since the lever arm from the center of the
shaft to the contact area on the surface 70 through which the lip 62 acts is
larger than the lever arm through which the seals 60 and 61 act, the drag of
lip 62 is greater than that drag exerted by the lips 60-61. For these reasons,
the lip 62 is able to yieldably resist creep (rotational movement) of the outer
race ring 50 within the housing 16 and oscillation (axial or rocking movement)
of the outer race ring 50 within the housing 16.
To aid in excluding contamination, the lip 62 is carried along the
radially extending face or edge 73 of the outer race ring 50 while the first
lips 60 project radially inwardly below the inner surface of the outer race
ring 50. The lip 62 also serves to seal against entry of contaminants between
the non-rotating housing 16 and outer surface 54 of the non-rotating outer race
ring,50. Since very little rotational movement between these parts occurs,
'~ the lip 62 does not flex to wipe contaminates away or permit lubricant to
-- 6 --
.
..........
~ ~ .
- , ' ~: . ' ' ' '
~L0876~7
.
escape from the reservoir 78 formed between the housing 16 and ring 50 to flush
the contaminates away. However, due to its designed ability to exert signifi-
cant pressure against the surface 70, it is able to serve as a seal as well.
The embodiment, illustrated in Fig. 3 as well as those alternative
embodiments illustrated in Figs. 4 and 5 include a separate metal core or
stiffening means 64, with the embodiments illustrated in Figs. 3 and 4 having
axially extending perforations 74 therethrough. The radially extending perfora-
tions 74 through the core 64 permit the first and second seal lips 60 and 62
to be integrally formed of the same material and therefore to have an increased
resiliency and strength.
Referring again to Fig. 2, there is shown a means for introducing
lubrication into the bearing. A lubrication fitting 76 is supported by the
flange half 36. Formed between the flange halves 36 and 38 is a cavity 78 in
communication with the lubrication fitting 76. Extending axially through the
outer race ring is a small opening 80. Sealing this cavity or grease reservoir
78 against leakage as lubrication is introduced into the fitting 76 is a thin
gasket 82 between the flange halves 36 and 38.
Figs. 4 and 5 illustrate substantially similar seal configurations
having alternate core members 64 and 84. The configuration illustrated in
Fig. 5 is designed for resilient contact between the wiper seal 62 and the outer
periphery 86 of the adjacent spool 42 so as to retard entry of dirt into the
area 88 which is adjacent the inwardly extending resilient lips 60. The core 64
illustrated in Fig. 4 is designed to provide additional support for the outer
surace 90 of the wiper lip 62 so as to assure better contact between it and
the inner surface 70 of the flanges at portion 72.
Figs. 6 and 7 illustrate separate seal lips 92 and 94 respectively
joined to unitary cup supports 66 and 96 which permit separate seal materials -
; to be utilized in the production of the seal lips 92 and 94.
~'' .
. :, . . .
:.
., ~
.. .. . ...
... , .. . . , . ~
., . , ... - :. . : - -
- , .
~ 10~1766~
Figs. 7 and 8 provide alternate cup support configurations 96 and 98
which include a crimped surface attached to the outer bearing race ring 50.
Fig. 8 provides an alternate embodiment wherein a single metal core member
serves as the stiffening means as well as the cup support 98 for attaching the
seal with the outer bearing race ring 50.
Illustrated in Figs. 3, 4, 5 and 7 are cup supports 66 having
vertically extending wall portions 100 inwardly spaced from and adjacent to
the innermost lip surface designated 102 of the inwardly extending wiper lips 60.
This wall portion 100 is provided to assure that upon assembly of the outer race
ring 50 and seal 58 upon the inner race ring 48, the inwardly extending wiper
lips 60 do not roll over and project at their ends toward the ball bearing anti-
friction means. Further, the wall portion 100 prevents the lips 60 from becoming
inverted by external pressure from contaminates.
Typically, two or three bearing supports 16 will be utilized to carry
the shaft 14 and its disk harrow blades 12. Due to the vertical and horizontal
forces encountered by the blades 12 during operation and thus transferred to the
bearing supports 16, the shaft 14 may not be precisely aligned within all of the
bearing supports 16. The bearings 46 therefore must be self-aligning and capable
of compensating for the initial misalignment, and dynamic misalignment during
operation.
As the disk harrow is pulled through the field and the disk blades 12
rotate, both vertical and horizontal forces are transferred through the disk
~- blades 12 to the shaft 14 and its supporting bearing structure. These forces are
further transferred to the disk frame 10 by each of the bearing supports 16
thereby transmitting to adjacent bearing supports 16 fluctuating horizontal and
vertical forces. Accordingly, the bearings which support the shaft 14 must be
; capable of accommodating some wobble with respect to the shaft, and oscillating
movement of support 16 and flanges 36 and 38 with respect to the outer race ring
-- 8 --
,~ .
. .... ~ . - :
, ~ ':, , ' :' ': .
. , , :
- , : - , , . , . . :
' ' . ' - . ' : : : . ~ :
, . : : : . . . - . . . : ~ . , - :
- - ' ' : , . . ' . ' ., '
:. . : , : . . :
.:
1~8766~
50. It is for this reason that the grease reservoir 78 must be provided to
lubricate the surfaces 56 and 54 between the flanges 36 and 38 and the outer
race ring 50.
As the disk blades 12, shaft 14 and inner race ring 48 rotate during
field operations, water, dirt, sand and other contaminants will cover the
support 16 and spacer spools 42 and 44. Looking again to Figs. 2 and 3, it
will be seen that to prevent entry of these contaminants through the space
between the inner surface 56 of the flange half 36 and the outer surface 54
of the outer race ring 50 and into the grease reservoir 78 formed between the
10 outer race ring 50 and the flange 36, the seal 58 wipes against the inner
surface 70 of the flange 36. As the shaft 14, inner race ring 48 and spool
spacers 42 and 44 rotate, the wiper lip 62 wipingly engages the outer periphery
86 of the spool 42 and seals against entry of contaminants into the cavity 88.
It is this seal lip 62 which permits the use of flanges 36, 38 that form with
the spools 42 and 44 sizeable gaps 104 that facilitate lateral oscillation
of the flanges 36, 38 about the outer race ring 50.
A V-groove indentation 106 is provided in the periphery of the spool
spacers 42 and 44 adjacent to the bearing support 16. This groove 106 permits
wire and similar materials to wrap about it rather than slide into the opening
- 20 or gap 104 between the flange and spool peripheries adjacent to the bearing
rings.
While the existing wiper seal embodiments all illustrate lip surfaces
in contact with the outer periphery of the spools 42 and 44 adjacent to the
bearing inner race ring 48, such contact is not always desirable, as it should
not be such as to interfere with the ability of the lip 62 to frictionally
prevent movement of the outer race ring 50 relative to the housing 16. As long
as the wiper lip 62 continues to wipingly engage the inner surface 70 of the
flange portion 72 and the inwardly extending seal lip 60 continues to engage
_ g _
., , ,. , ,. . .. . . . ... :. - . : : : ' '
, : . : . .. . . .
. .. : . ~ , . ~ . - , ' :
. . . , : : . . ,: :
. . . . . . .
~766~
the outer circumferential surface 68 of the inner race ring 48, whatever dirt or
contamination that might enter between the flange portion 70 and outer peripher-
ies of the spools 42 and 44 will be wipingly pushed out the gap 88 and 104 as
the shaft 14, spools 42 and 44 and inner race ring 48 rotate within the bearing
support 16, allowing seal lips 60 to flex during relative misaligned movement
between the inner race ring 48 and the outer race ring 50.
With this improved seal configuration the expected life of the seal,
bearing surface and therefore the bearing support can be extended so as to
minimize the lost time incurred for repla-cement activity during the operating
season.
-- 10 --
.,~ '' :
. . , , , ~
.. ... .
, : , : '
, '~', ' ~ ,: ' : .
-: . . ' - . '. ::
. . '.: ' .
~76~;~
~ .
SUPPLEMENTARY DISCLOSURE
In the principal disclosure, it has been specified that it is not
necessarily desirable that the seal lip 62 contact the outer periphery of the
spacer spool 42 adjacent the inner race ring 48, although this arrangement is
shown in the drawings as for example Fig. 3. Particularly when the seal lip
does not contact the spacer spool 42, it is a preferred feature that the axially
outermost of the lips 62 be formed with a thicker cross section to increase the
pressure it can exert against the inner race ring 48 and improve the seal against
entry of contamination. This thicker lip is also better able to exclude
accumulation of dirt that may enter between the housing flange 72 and collar 42.
This improvement is, however, of benefit as well when incorporated in the
embodiments shown in the drawings.
, -- 11 --
.
- . , : . : , . .
