Note: Descriptions are shown in the official language in which they were submitted.
The present invention relates to improvements in devices
including members mounted for relative rotation about a spindle
which projects from an end face o~ the said member.
The invention is particularly, although not exclusively,
concerned with devices in which the members are rollers, and is
more especially concerned with idler roller assemblies used for
supporting a conveyor belt.
Accordingly the present invention provides an idler
roller assembly used to support a conveyor belt comprising a
tubular portion forming the roller, at least one end of which
is enclosed by a member to provide an end face, said member
including an axially aligned aperture and bearing located con-
centrically inwardly thereof, said assembly being mounted for
rotation about a spindle projecting through said aperture and
journalled in said bearing, wherein said member includes an
annular flange having a portion projecting outwardly thereof
and parallel to said spindle, there being at least sliding
clearance between the said flange and the said spindle.
Preferably both ends of the said tubular portion are
20 enclosed by members providing end faces each said member
including an axially aligned aperture and a bearing for
mounting on the spindle. Such a spindle need not, of course,
be continued throughout the length of the roller, but may
be in the form o~ a stub axle one such axle being provided at
each end of the roller.
, Hitherto, in conveyor belt supporting, the roller in an
-~ idler roller assembly, in which the roller is rotatably mounted
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on a stationary spindle by means of bearings, each present two
end faces that are plain. Each such end face is formed with
a cen-tral hole through which the spindle projects. A seal is
usually provided on the spindle behind the end face
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of the rollar to prevent the ingress of water and debris into
the bearing through the clearance gap which in~ariably exists
between the spinle and hole. In some conseructions the seal
extends along the spindle and along the hole in the roller end
wall to a point where it terminates flush with the end face of
the roller.
However, whether a seal is provided or not, in the harsh
conditions of usage to which such assemblies are normally
exposed, water and/or o$1 with entrained dirt frequently pass
through the clearance gap between the spindle and hole in the -~
roller end face and lead to an early break-down of the bearing.
It has been found that dirt or other debris accummulates
on the end face of the roller and it is principally some of this
accummulation of dirt which enters into the bearing through the
clearance gap. The problem is aggravated by, for example, rain
water washing the dirt down the end face when the roller is
stationary and onto the spindle ad~acent the clearance gap.
A roller assembly construc~et in accordance with the present
in~ention guards against the ingress of water and dirt or other
debris in that the flange guards the clearance gap against the
f low of water by deflecting the water away from the gap.
Yreferably the f lange is located immediately adjacent to
the spindle and more preferably a seal extends along the
spindle to a point where lt termi~ates fl~sh with the pro~ecting
end of the flange. In this preferred for of construction
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there is little surface area adjacent to ~he clearance gap
against which dirt can accummulate. For this reason the flange
is made as thin as is compatible with the s~rang~h required for
it to resist deformation and damage occasioned by the conditions
of use~ -
Embodiments of the invention wilL now be des~ribed by way
of example, with reference to the accompanying drawings in
which:-
Figure 1 is a front view partially in section ofa device according to the invention in the
form of an idler roller assembly of a belt
conveyor.
Figure 2 is a part-secional view of a detail of
another construction of rolLer assembly.
Figure 3 is a view similar to Figure 2 of a further
embodiment of the invention.
The roller assembly shown in Figure 1 includes a roller 11
rotatably supported at each end on a spindle lO. For con~
venience one end only of the roller assembly will be described;
the construction at each end being the sameO
The roller 11 is of welded construction and comprises an
outer tube 12 and a generally disc~shaped plate secured to each
end of the ~ube 12 to form an end ~ace 14~ A hole 14a is formed
in the disc plate through which the spindle 10 pro~ects.
Secured to the inside of the end face 14 is a tubular bearing
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housing 15 within which the outer race of bearing 13, which
supports the roller 11 on the spindle 10, is located. The
spindle 10 is of stepped construction having a shoulder 1~
about which the inner race of the bearing 13 seats. A resilient
annular seal assembly 17 is located between the bearing 13 and
the inner face of end face 1~.
The end face 14 ~s formed with an integral flange 19 which
defines the circumference of the hole 14a~ Seal 18 in the
form of a collar is mounted on the spindle 10 and projects
along the spindle and terminates flush with the end of the
flange 19. The necessary clearance gap 20 which is provided
between the outer diameter of the seal 18 and the bore of the
flange 19 is as small as possibleO The flange 19 at its outer
end is as thin as is compatible with the necessary strength
required to resist damage in the conditions of use to which
the roller is subjected.
When installed for useg dirt or other debris may accumulate
on the outside of the end face 14 and may build up in the angle
fromed between the outside face and flange 19. However, the
area against which dirt~ which might enter the clearance gap
20 between the flange 19 and seal 18 can accumulate is restricted
to that immediately ad~acent the spindle 10 presented by the
end edges of the flange 19 and seal 18
Idler roller assemblies are often employed in exposed
conditions where rain water can carry dirt do~ the end face of
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the roller towards the spindle and thus towards the clearance
gap between the spindle and roller. Such a movement of accum-
ulated dirt is a particular probLem when the roller is stationary.
However9 in the construction descrlbed above in which a flange
projects from the end face, such rain water will flow around
the flange and thus be deflected and prevented from carrying
dirt to the clearance gap between the flange and the seal.
Thus, a roller, constructed in accordance with the present
invention restrains foreign matter from ingress into the roller
to attack the bearing, above and beyond the restraint imposed
usually merely by maintaining the clearance gap as small as
possible.
The constructions shown in Figures 2 and 3 of the drawings
are similar to that shown in Figure 1 and the same reference
numerals are employed to denote the same or similar components.
The construction shown in Figure 2 differs from that of
Figure 1 in that the Elange 19 is provided by a separate annulus
of L-shaped cross-section which is a press fit in the hole in
the end wall 14 of the roller ll. The cons~ruction shown in
Figure 3 is another modification in which the flange 19 is
constructed by welding to the end w~ll a tubular sleeve which
has a stepped portion ins~rted in the hole in the end wall.
As is shown in the construction described in conjunction
with the accompanying drawings, it is preferred that the flange
be dlsposed immediately ad~acent to the spindle, or where the
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spindle includes a seal to the outer diameter of the seal, but
advantages are also to be found in construction wherc the
flange pro~ects from the face at a location up to one third
of the radius of the end wall from the spindle. For example
such a construction might take the form of a modification
of the construction described in conjunction with Fiugre 1 in
which the tubular bearing.housing 15 projects through an en-
larged hole in the end plate 14 to form a Xlange and in which
a resilient seal closes the gap between the inside diameter
of the housing 15 and the spindle 10.
As indicated aboYe although the construction described
particularly herein all have spindles including seals 18,
advantages are to be found in constructions wherein the flange
19 immediately surrounds the spindle 10 in the absence of a
seal.
In devices sur-h as the rollers described particularly
herein~ the member rotates while the spindle 10 is held stat-
ionary in a mounting, but the invention may be applied in con~
structions where the member is stationary and the spindle 10
rotates.
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