TANDEM SEAL FOR A CONVEYOR ROLLER

JOINT TANDEM DESTINE A UN ROULEAU CONVOYEUR

English Abstract

A tandem seal, according to the present invention, is provided for a conveyor roller having a drum body with opposing ends rotatably mounted on an axle by way of a bearing assembly within a flanged housing attached at either end of the drum body. The tandem seal has an end cap rigidly mounted within the flanged housing, extending radially inwardly towards the axle and spaced apart therefrom. A guard is rigidly mounted on the axle and extends radially outwardly from the axle and is spaced apart from the end cap. A first contact seal seals the space between the guard and the end cap and a second contact seal seals the space between the axle and the flanged housing.

French Abstract

La présente invention concerne un joint tandem destiné à un rouleau de transporteur ayant un corps de tambour avec des extrémités opposées montées de manière rotative sur un axe au moyen dun mécanisme de roulement à billes dans un logement à bride qui est fixé à lune ou lautre des extrémités du corps de tambour. Le joint tandem a un bouchon de protection dans le logement à bride, ledit bouchon sétendant radialement vers lintérieur en direction de laxe et étant espacé de celui-ci. Un protecteur est fixé solidement à laxe, sétend radialement vers lextérieur à partir de laxe et est espacé du bouchon de protection. Un premier joint de contact scelle lespace entre le protecteur et le bouchon de protection, et un second joint scelle lespace entre laxe et le logement à bride.

Claims

What is claimed is:
1. A tandem seal for a conveyor roller, having a drum body with opposing
ends, and
axle, a bearing assembly, and a flanged housing attached at either end of the
drum body
.. and spaced apart from the axle, wherein the flanged housing is shaped to
define an end
wall and an annular space between the flanged housing and the axle, and
wherein the
frum body is rotatably mounted on the axle by way of the bearing assembly
within the
annular space defined by the flanged housing, the tandem seal comprising:
an end cap rigidly mounted to the flanged housing axially outwardly from the
bearing assembly within the annular space extending radially inwardly from the
flanged
housing towards the axle and spaced apart from the axle;
a guard rigidly mounted on the axle axially outwardly from the bearing
assembly
extending radially outwardly from the axle and spaced apart from the end cap;
a first contact seal positioned axially outwardly from the bearing assembly
sealing
the space between the guard and the end cap; and
a second contact seal positioned axially outwardly from the first contact seal
sealing the space between the axle and the end wall of the flanged housing.
2. The tandem seal, according to claim 1, wherein the first and second
contact seals
remain rotationally stationary relative to the axle as the drum body rotates
thereon.
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Date Recue/Date Received 2022-06-06

3. The tandem seal, according to claim 2, wherein the first seal is a v-
ring seal seated
on the guard having a lip that extends radially outwardly and is biased
against the end
cap to form a contact seal therewith.
4. The tandem seal, according to claim 3, wherein the second contact seal
is a
gasket-type seal seated on the axle that extends radially outwardly and is
biased against
the end wall of the flanged housing to form a contact seal therewith.
5. The tandem seal, according to claim 4, wherein the second contact
seal is located
axially adjacent to and abutting the guard.
Date Recue/Date Received 2022-06-06

Description

Tandem Seal for a Conveyor Roller
Field of the Invention
The present invention relates to conveyor rollers and, in particular, to seals
for
conveyor rollers.
Background
Conveyor belts are widely used in a diverse set of industrial and commercial
applications. Many industrial operations, such as mining or other resource
extraction
operations rely on conveyor belts to move large quantities of heavy material
between
processing steps in the operation.
Many of these operations produce low-cost resources and depend on large
high-speed, high-volume conveyor belt systems to provide the necessary
throughput to
make the operation profitable. In such operations, machine maintenance,
including
maintenance of the conveyor belt, and the resulting downtime, is carefully
planned and
scheduled to maximize productivity and, thus, profitability of the operation.
Contamination of the roller mechanism by dust and debris from the
surrounding operation is a significant problem for conveyor rollers and can
cause failure
of the roller and result in costly unscheduled downtime. When a roller
requires
unscheduled maintenance, the entire conveyor belt system, and other all
associated
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processes, must be shut down to access and replace the roller. The financial
cost to an
operation, associated with a process-wide shutdown, can be unacceptably high.
Accordingly, there is a need for seals that minimize contamination of the
roller
mechanism with dust and debris, during conveyor operations, to prevent or
reduce
unscheduled downtime of conveyor belts, due to roller failure caused by
contamination of
the roller mechanism.
Summary of the Invention
A tandem seal, according to the present invention, is provided for a conveyor
roller having a drum body with opposing ends rotatably mounted on an axle by
way of a
bearing assembly within a flanged housing attached at either end of the drum
body. The
tandem seal has an end cap rigidly mounted within the flanged housing,
extending radially
inwardly towards the axle and spaced apart therefrom. A guard is rigidly
mounted on the
axle and extends radially outwardly from the axle and is spaced apart from the
end cap.
A first contact seal seals the space between the guard and the end cap and a
second
contact seal seals the space between the axle and the flanged housing.
Brief Description of the Drawings
In order that the invention may be more clearly understood, a preferred
embodiment thereof will now be described in detail by way of example, with
reference to
the accompanying drawings, in which:
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Figure 1 is an isometric view of an idler roller including the tandem seal,
according to the present invention.
Figure 2 is a sectional view of the idler roller, shown in Figure 1.
Figure 3 is a closeup sectional view of the area at the end of the idler
roller
marked Z in Figure 2, with the tandem seal shown with hash lines.
Figure 4 is a side sectional view of the tandem seal on one end of an idler
roller.
Figure 5 is an exploded side view of the tandem seal, along with the other
components at each end of an idler roller.
1.0 Figure 6 is an isometric exploded view of the tandem seal, along with
the other
components at each end of an idler roller.
Figure 7 is a sectional view of the tandem seal, along with the other
components at each end of an idler roller, shown in Figure 5.
Description of the Preferred Embodiment
A tandem seal for a conveyor roller, according to the present invention, is
installed as part of the sealing structure at each end of a conveyor roller to
prevent ingress
of contaminants, such as dust or debris into the roller mechanism. The
invention will be
hereafter described with reference to an idler roller, but may be used to seal
other types
of rollers. Further, the tandem seal may be used with a conveyor roller not
including one
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or more of the components described below, not forming part of the tandem
seal, so long
as the conveyor roller has a drum body rotatably mounted on an axle.
As shown in Figures 1 and 2, an idler roller has a hollow cylindrical drum
body
1, which is rotatably mounted on an axle 2 by way of a bearing assembly 3,
located
adjacent each end la of the drum body 1. The drum body 1 has a length that is
preferably
shorter than the length of the axle 1 to permit installation of the idler
roller with the axle 2
attached to opposing supports, such as in a conveyor (not shown).
As shown in Figures 2-4, the bearing assembly 3 adjacent each end la of the
drum body 1 is mounted within a flanged housing 4 extending radially inwardly
from the
drum body 1. The flanged housing 4 is shaped to define an end wall 5 of the
drum body
1 and an annular space between the flanged housing 4 and the axle 2.
Preferably, the
flanged housing 4 has a generally Z-shaped cross section, with two 900 bends.
The
radially outward perimeter edge 6 of the flanged housing 4 is rigidly attached
to the drum
body 1. The radially inward perimeter edge 7 of the flanged housing 4 is
spaced apart
from the axle 2, so as not to come into contact therewith. As shown in Figures
3 and 4,
a portion of the length of the drum body 1 at each end may have a reduced
thickness to
form a shoulder lb on which the radially outward perimeter edge 6 of the
flanged housing
4 is seated and attached.
The components within each flanged housing 4 at either end la of the drum
body 1 are described hereafter, generally from the component furthest from the
end la,
in the axially inward direction, to the component closest to the end la. These
components
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are shown in Figures 5-7 in exploded views from the furthest axially inward
component at
the left of the page, to the furthest axially outward component at the right
of the page.
As shown in Figures 3-5, an inner seal 8 may be seated between the bearing
assembly 3 and the flanged housing 4 axially inwardly from the end la of the
drum body
1. Preferably, the inner seal 8 is a rubber 0-shaped grease cap and prevents
lubricant
from the bearing assembly 3 from leaking into the drum body 1.
The bearing assembly 3 is mounted within the annular space between the axle
2 and the flanged housing 4. A radial ball bearing may be used, but other
suitable bearing
assemblies 3 may also be used. The inner ring of the radial ball bearing
rotates with the
axle 2, while the outer ring of the radial ball bearing rotates with the
flanged housing 4
and the drum body 1. A plurality of ball bearings are positioned therebetween,
within a
cage to keep them in place, thereby permitting rotational motion of the drum
body 1
relative to the axle 2. A ring clip 9 is seated within a complementary groove
9a on the
axle 2 adjacent the bearing assembly 3 to keep it in place.
A labyrinth seal, with an outer labyrinth seal 10 and an inner labyrinth seal
11
is position adjacent the bearing assembly 3, axially outwardly toward the end
la. The
outer labyrinth seal 10 abuts the flanged housing 4 and is spaced apart from
the axle 2.
The inner labyrinth seal 11 abuts the axle 2 and is spaced apart from the
flanged housing
4. Accordingly, the outer labyrinth seal 10 rotates with the drum body 1
relative to the
inner labyrinth seal 11, while the inner labyrinth seal 11 remains stationary
on the axle 2.
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As shown in Figures 6 and 7, the outer labyrinth seal 10 is a flat ring-like
structure extending radially inwardly towards the axle 2. A plurality of
concentric circular
walls 10a extend axially outwardly therefrom and define a plurality of grooves
therebetween. The inner labyrinth seal 11 has a complementary structure, with
a plurality
of concentric circular walls 11a that extend axially inwardly therefrom
configured to fit
interlockingly with the walls 10a of the outer labyrinth seal 10, as shown in
Figures 2-4.
The outer and inner labyrinth seals 10 and 11 do not form a contact seal with
one another,
but rather provide a convoluted path through which any debris or contaminants
must
travel before reaching the bearing assembly 3.
Hereafter, the tandem seal will be described with reference to the example of
the idler roller herein described. Although the tandem seal is described as
interacting
with various components of the idler roller, it may be adapted for use with
other conveyor
rollers that do not include these components.
As shown in Figures 3-7, an end cap 12 having a generally L-shaped cross-
section is fitted between the outer labyrinth seal 10 and the flanged housing
4 and extends
radially inwardly toward the axle 2. A small space is provided between the
radially inward
edge 12a of the end cap 12 and the axle 2. Alternatively, the radially inward
edge 12a
may be spaced apart from another component mounted on the axle 2, such as the
guard
13, as described below. The end cap 12 is rigidly mounted within the flanged
housing 4
and therefore rotates relative to the axle 2 with the drum body 1.
As shown in Figures 3 and 4, a guard 13 is fitted between the axle 2 and the
inner labyrinth seal 11 and extends radially outwardly from the axle 2 and is
spaced apart
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from the end cap 12 and the flanged housing 4. The guard 13 may also curve
axially
inwardly towards the end cap 12, without coming into contact therewith, to
define a space
between the guard 13 and the end cap 12 for a first contact seal 14. The guard
13 is
rigidly mounted on the axle 2 and therefore remains stationary relative to the
axle 2 as
the drum body 1 rotates thereabout.
As shown in Figures 2-4, the first contact seal 14 is seated on the guard 13
about the axle 2. The first contact seal 14 forms a contact seal between the
guard 13
and the end cap 12. Preferably, the first contact seal 14 is a v-ring seal,
which is seated
on the guard 13 within the space between the guard 13 and the end cap 12. The
first
contact seal 14 has a lip 14a that engages with the radially inward edge 12a
of the end
cap 12 to form a contact seal therewith. The lip 14a is biased against the end
cap 12 so
as to remain in sealing engagement therewith, as the end cap 12 rotates
relative to the
axle 2. The first contact seal 14 is preferably made of rubber or other
suitable material.
During operation, the first contact seal 14 is seated on the guard 13 and
remains stationary relative to the axle 2, while the drum body 1, flanged
housing 4, and
end cap 12 rotate thereabout. The lip 14a extends radially outwardly from the
guard 13
and rides on the radially inward edge 12a of the end cap 12 to form a contact
seal and
seal the space between the guard 13 and the end cap 12.
As shown in Figures 2-4, a second contact seal 15 is seated on the axle 2
axially outwardly adjacent to the guard 13. The second contact seal 15 forms a
contact
seal between the axle 2 and the end wall 5 of the flanged housing 4.
Preferably, the
second contact seal 15 is a gasket-type seal, or weather seal that fits
closely about the
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axle 2 and extends radially outwardly therefrom to engage sealingly with the
end wall 5.
The radially outward edge 15a of the second contact seal 15 is biased against
the end
wall 5 so as to remain in sealing engagement therewith as the end wall 5
rotates relative
to the axle 2. The second contact seal 15 is preferably made of rubber or
other suitable
.. material.
The present invention has been described with reference to an exemplary
embodiment, however, it will be understood by those skilled in the art that
various
changed may be made and equivalents may be substituted for elements thereof
without
departing from the scope of the invention as set out in the following claims.
Therefore, it
is intended that the invention not be limited to the particular embodiments
disclosed
herein, but that the invention will include all embodiments falling within the
scope of the
following claims.
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Representative Drawing