Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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DRYER DRUM BEARING ASSEMBLY
FIELD OF THE INVENTION
The present invention relates to a clothes dryer and in particular to a
support bearing structure for supporting and electrically grounding a drum of
the clothes dryer.
BACKGROUND OF THE INVENTION
In the past, bearing structures used in domestic clothes dryers have
been expensive to manufacture, due to a large extent on the number parts
and dictated by the design. Typically the bearing structure comprises a shaft
carried by a rotating drum and a molded plastic bearing fixed to a stationary
wall of the dryer. The grounding of the drum is done by a formed metallic
spring loaded blade that is forced against the end of the shaft. The
stationary
wall is typically mounted spaced inwardly of the rear outer panel wall of the
dryer. .The use of such a stationary wall mounted inwardly of the rear panel
limits the size of the dryer drum mounted within the cabinet. Examples of
such bearings used in clothes dryers are shown in U.S. patent 3,009,259
issued to Simpson, U.S. patent 3,429,056 issued to Metzger, U.S. patent
3,721,015 issued to Sister et ai, U.S. patent 4,069,596 issued to Sister, U.S.
patent 4,467,534 issued to Murase and U.S. patent 6,062,049 issued to
Martinsson.
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Other clothes dryer bearing assemblies that are mounted to the rear
panel wall of the dryer or pass through such a wall as shown in US patent
3,483,632 issued to Triplett, U.S. patent 3,567,297, issued to Triplett et al,
U.S. patent 3,805,408 issued to Shadley, and U.S. patent 5,483,756 issued to
Heyder. However, these patents ail disclose some portion of the bearing
assembly being positioned outside the cabinet.
With the recent increases in drum size utilized in clothes dryers, it is
becoming more advantageous for the drum to utilize as much space as
possible within the cabinet. As a result the clearance space for the bearings
and the drum grounding means within the dryer cabinet have become more
critical.
Accordingly, there is a need to provide a new and improved clothes
dryer having a new and improved bearing, bearing support structure and
drum grounding housed within the dryer cabinet that improves clearance
space and drum capacity.
SUMMARY OF THE INVENT10N
The present invention relates to the use of a bearing assembly within a
clothes dryer wherein the bearing assembly and grounding means permits for
reduced space between the rotating drum rear end head and the rear panel of
the dryer cabinet.
The clothes dryer of the present invention has a bearing assembly for
supporting the rotating drum of the dryer for rotation about a substantially
horizontal axis. The bearing assembly also provides a low cost grounding
means for grounding the drum assembly of the dryer. The bearing assembly
has a shaft having a first end portion mounted in fixed relation to a rear
wall of
the drum to rotate therewith. The assembly includes a rear panel of the dryer
having a recessed panel wall portion that defines a bearing chamber. The
assembly further includes a bearing retainer mounted to the rear panel and
inserted into the recessed bearing chamber. The bearing retainer has an
opening and a bearing seat portion. A small rectangular flat bearing pad
member is folded and pushed into the seat portion. The bearing retainer and
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bearing assembly are located within the recessed bearing chamber for
supporting at least a portion of the bearing shaft for rotation therewith
within
the recessed bearing chamber.
The bearing retainer preferably provides a nest for positively locating a
grounding strap to provide proper grounding of the drum when the bearing
retainer is in the recessed chamber and the drum shaft is in its operating
position.
The present invention provides for an effective bearing arrangement
which allows for a positive and easily assembled bearing and drum grounding
means for a clothes dryer wherein the rear wall of the clothes dryer has a
recessed portion to permit for a larger drum structure to be located within
the
clothes dryer without any of the bearing assembly located outside of the dryer
cabinet.
BRIEF DESCRIPTION OF THE DRAWINGS
For a better understanding of the nature and objects of the present
invention, reference may be had to the accompanying diagrammatic drawings
in which:
Figure 1 is a view showing an electric clothes dyer having the bearing
structure of the present invention;
Figure 2 is a top sectional view taken along shaft axis line 2-2 in Figure
1 and illustrates the bearing retainer and the grounding strap of the present
invention;
Figures 3a and 3b are respectively front and rear perspective views of
the bearing retainer of the present invention, and Figure 3b shows the
location of the grounding strap in the bearing retainer during assembly;
Figures 4a and 4b are respectively front and rear perspective views of
the cover for the bearing of the present invention; and,
Figures 5a and 5b illustrate the bearing pad respectively in its free
shape and operating shape;
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Figure 6 illustrates the grounding strap in its free shape; and
Figure 7 is a partial section enlarged view illustrating the flexible
connection and mounting of the bearing retainer to the rear panel of the
dryer.
DETAILED DESCRIPT10N OF THE PREFERRED EMBODIMENT
Referring to Figure 1 there is shown a clothes dryer 10 having a
rotating drum 12 mounted within the dryer cabinet 11 for rotation
substantially
about horizontal axis 15. The rotating drum has an open front through which
access can be gained through door 14 of the dryer 10 for the insertion and
removal of clothing and other articles from the drum. The clothes dryer 10
has a rear panel 16 provided with a series or plurality of louvers 18 through
which air may be drawn into the interior of the dryer 10. The airflow is shown
by arrows 20 passing through the louvers, through a series of openings (not
shown) in the rear end head 22 of the dryer drum 12, through front ducting 24
and out through exhaust ducting 26. Motor 28 rotates fan 30 to draw the air
20 through the drum 12. The motor 28 through pulley 35 and belt 33 also
causes the rotation of the dryer drum 12.
A heater housing 32 is mounted by suitable bolts 34 to the rear panel
16 of the dryer 10. The heater housing 32 is adjacent the end head 22. The
heater housing 32 has a rear wall 36 that is spaced from the rear end head
22.
Helically wound heater coils 48 are mounted via electrical insulators 50
to the rear wall 36 of the heater housing 32. The coils 48 are spaced from the
rear walls 36 and from the end head 22 of the dryer drum. The heater coils
48 are connected to a source of electrical supply through terminals 52. When
electrical energy is fed through terminals 52 to coils 48, the heating coils
warm air passing over the coils and towards the openings 23 in the end head
22 and perforated wall 60 of the dryer drum 12.
The drum 12 is mounted to the front panel 13 through a bulkhead (not
shown) that supports the front portion of the drum. The rear portion of the
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drum 12 is supported to the rear panel 16 of the dryer cabinet by bearing
assembly 70.
Referring to Figure 2, the bearing assembly 70 is shown
interconnecting the rotating drum 12 to the rear panel 16 of the cabinet of
clothes dryer 11. The drum 12 is connected to the end head 22 of the drum
12. Also connected with the end head 22 is perforated wall 60 that distributes
heated air into the dryer drum. The perforated wall 60 has a recessed button
shaped portion 72 and is connected at raised land portions 74 either by
screws or rivets (not shown) to an end head cover 76 of the bearing assembly
70.
Referring to Figures 4a and 4b, enlarged views of the end head cover
76 are shown. The end head cover 76 has a raised flattened dome shaped
central portion 77 that is raised by a predetermined distance to define,
between it and the recessed portion 72 of the perforated wall 60, a chamber
78 for receiving through the cover 76 a shaft 80. The cover 76 has openings
130 which will permit for the fastening of cover 76 to the rear end head 22
and the perforated wall 60.
Shaft 80 is elongated and has one end 132 having threads 134 onto
which a nut 82 is secured. Shaft 80 has a shoulder 84 which engages the
dome 77 of cover 76 when the shaft 80 is passed through an aperture (not
shown) in the cover 76 and the nut 82 is tightened against the inner surface
79 of the cover 76. As a result, the shaft 80 rotates with rotation of the
cover
76 which rotates with rotation of the drum 12 and end head 22. Thus
securing of the nut 82 onto the stem 80 against inner surface 79 of the cover
76 effectively mounts the drum 12, perforated wall 60 and end head 22 for
rotation with the shaft 80. The other end 81 of the shaft 80 is inserted into
bearing support or bearing retainer 88.
Referring to Figures 2, 3a, 3b, 5a, 5b, 6 and 7, the improvements of
the preferred aspects of the present invention are now described. Bearing
retainer 88 has a flange portion 89 that overlaps the rear panel 16 and is
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mounted thereto by snap action locking tabs 99. 1'he rear panel 16 has a
recessed wall 92 recessed from the rear panel 16 by side walls 93 to define a
receiving or recessed bearing chamber 95. Two tabs 112 are pierced and
formed out of panel 16 adjacent corners 9T of walls 93 and 92.
The bearing retainer 88 is inserted into recessed chamber 95 of rear
panel 16 and has an opening 94 (see Figures 3a and 3b) through which shaft
80 may be inserted. The opening 94 opens up into an enlarged channel 96
that has an upper curved surface 98 adjacent to which the shaft 80 is
positioned and a lower curved seat 100 of larger radius than the radius of the
shaft 80. A bearing pad 102 is curved from its normal state shown in Figure
5a into its curved shape illustrated in Figure 5b and inserted onto the lower
curved seat 100 for supporting the stem 80. The bearing pad 102 may
comprise a suitable plastic material of low friction such as, for example,
polytetrafluoroethylene (PTFE), more commonly know by its trade name
Teflon.
The bearing retainer 88 also has four protruding legs 122 which abut
the recessed wall 92 of the recessed chamber 95 of the rear panels 16. The
legs 122 act to positively locate the bearing retainer 88 within the recessed
chamber 95. Legs 122 also positively locate, or nest between the two pairs of
spaced apart legs 122 and across the channel 96, a ground strap 110 shown
in broken line in Figure 3b and in its normal flat state in Figure 6. The
ground
strap 110 is normally a flat elongated spring steel blade or leaf spring like
member.
During assembly, the bearing pad 102 is placed onto seat 100 of
bearing retainer 88. The grounding strap 110 is plac~sd between legs 122.
The bearing retainer 88 is then placed within the recessed chamber 95 with
legs 122 abutting portions of walls 92 and 93. Ground strap 110 is held
captive by legs 122, walls 93 and tabs 112. As the shaft 80 is inserted
through opening 94 into chamber 95, it engages the ground strap 110. The
ground strap 110 is placed in a recessed channel formed by legs 122 of
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bearing retainer 88. The shaft 80 when inserted into the bearing retainer 88
has a tip portion 100 on its one end 81 that positively pushes and curves the
strap 110 against tabs 112 to create a positive grounding contact thereby
grounding the drum and shaft assembly to the grounded rear panel 16.
The bearing retainer flange 89 that is adapted to overlap inside surface
83 of rear panel 16 when the bearing retainer 88 is inserted into recessed
chamber 95. The flange 89 has a slotted opening 140 and projecting hook
like locking tabs 99. The slotted aperture 140 permits the tabs 99 to flex
relative to the flange 89. As illustrated in Figure 7, the rear panel 16 has
openings 90 pierced in the panel 16 that provide a recessed flange portion 91
extending behind the panel 16. The tabs 99 of flange 89 are flexed to pass in
through opening 9 of panel 16. The tabs 99 have a barb 101 that snaps over
the end of flange 91 to thereby secure the bearing retainer 88 against the
rear
panel 16 with the legs 122 of the bearing retainer seated in the recessed
chamber 95.
It should be understood that the thickness of the shoulder 84 and the
displacement of the domes 77 of the cover 76 and the bearing retainer 88
define the clearance between the end head 22 of the drum 12 and the rear
panel 16. The present invention provides for an effective bearing and
grounding arrangement which allows for a positive and easily assembled
bearing for a clothes dryer wherein the rear wall 16 of the clothes dryer has
a
recessed portion to permit for a larger drum structure to be located within
the
clothes dryer without any of the bearing assembly being located outside of the
dryer cabinet 11. Further, in some alternative embodiments, the recessed
chamber 95 may extend outwardly from the rear panel. It should be
understood that in some cases a protruding chamber 95 would be
inconsequential to positioning the dryer adjacent a room wall because a
greater spacing distance is required by the dryer from the room wall to
accommodate venting of exhaust gas through the rear panel 16 of the dryer
10.
