[0001] The present invention relates to a cooling device, particularly for the drum bearings
of laundry driers.
[0002] Known domestic laundry driers are usually constituted by a frame or cabinet supporting
a revolving drum containing laundry to be dried by means of an air circulation system.
[0003] A processor, besides controlling the various operating parameters, periodically reverses
the drum rotation in order to prevent the laundry from getting entangled.
[0004] In the known machines, the revolving drum is supported in the frame by means of bearings
of different types, rolling or plain bearings, such as for example plastic sleeve
bearings.
[0005] These types of bearings wear out easily because of the high working temperature in
which they operate.
[0006] The aim of the present invention is to provide a cooling device adapted to lower
the working temperature of the drum bearings of domestic laundry driers.
[0007] Within this aim, an object of the invention is to provide a cooling device easily
adaptable to known laundry driers without substantially modifying the supporting systems
of the drum.
[0008] A further object of the invention is to provide a relatively simple device such as
not to affect the machine production costs considerably.
[0009] The above aim, as well as these and other objects that will be more apparent later,
are achieved by a cooling device, particularly for the drum bearings of laundry driers,
comprising a frame supporting said drum by means of bearings, characterized in that
at least one air passage is provided at each of said bearings for air coming from
the outside, said air being adapted to cool said bearings.
[0010] Further characteristics and advantages of the invention will be more apparent by
the following description of an embodiment of the invention, illustrated, by way of
example in the enclosed drawings in which
Fig. 1 is a sectioned side view of a laundry drier;
Fig. 2 is a side view of a bearing having a device according to the invention;
Fig. 3 is a side view of a bearing having a device according to another aspect of
the invention;
Fig. 4 shows a rolling bearing with a device according to a further aspect of the
invention;
Fig. 5 shows a bearing with a device according to a fourth aspect of the invention.
[0011] With reference to the cited figures, it is illustrated a laundry drier 1 essentially
constituted by a frame 2 supporting a revolving drum 3 adapted to contain the laundry
to be dried.
[0012] At the back it is shown a drum supporting bearing 4, which, for example, can be a
rolling ball bearing, as illustrated in figure 4, or a plain bearing with a plastic
sleeve ( figures 2 and 3 ) or with a brass ( figure 5 ).
[0013] Figure 2 shows a plain bearing 4a comprising a plastic sleeve 5 housed in the support
6 and containing a pivot 7 fixed to the drum 3.
[0014] The support 6 is fixed to the frame 2 of the machine, in a per se known manner not
illustrated here, and it is spaced from the wall 2a of the frame 2 to provide an air
passage around the bearing 4a, by means of air intakes 8 provided on the wall 2a at
pivot 7.
[0015] Fig. 3 shows a plain bearing 4b comprising a support 6 housing a sleeve 5 made of
plastics, substantially similarly to the preceeding one.
[0016] In this case pivot 7a, fixed to the drum 3, is hollow since it is provided with a
hole 9 for a passage of air which cools the bearing from inside.
[0017] Fig. 4 illustrates a rolling bearing 4c comprising a support 10, fixed to the wall
2a of the frame 2, and balls 11 interposed between the support and pivot 12 fixed
to the drum.
[0018] Pivot 12 is provided with an axial hole 13 for a passage of cooling air, in a way
similar to the preceeding one.
[0019] Fig. 5 shows a plain bearing 4d comprising a brass 14, housed in a support 15 fixed
to the wall 2a of the structure of the machine, and a pivot 16 fixed to the drum 3.
[0020] Pivot 16 is provided with an axial hole 17 for a passage of air and the support 15
too is provided with slots 18 at its connection with the wall 2a.
[0021] Naturally, also in the above described bearings it is possible to provide such a
double passage of air by providing air intakes on the support and an axial hole in
the pivot.
[0022] The air circulation needed for cooling is given by the air pressure inside the drum
being lower than the air pressure outside the machine; for this reason, during the
drying operation, fresh air keeps getting into the drum, through the provided intakes,
hitting the exterior of the support, crossing the pivot hole and thus considerably
cooling the entire rotating assembly.
[0023] It has been seen how the cooling device according to the invention achieves the intended
aims and objects by allowing the support bearings of the drum of laundry driers to
work in the best temperature conditions with a great advantage in terms of longevity
and reliability of these parts.
[0024] The cooling device according to the invention may have numerous modifications and
variations, all within the inventive concept; furthermore, all the details may be
substituted with technically equivalent elements.
[0025] The materials employed, as well as the dimensions, may be any according to the specific
needs and the state of the art.
[0026] Where technical features mentioned in any claim are followed by reference signs,
those reference signs have been included for the sole purpose of increasing the intelligibility
of the claims and accordingly, such reference signs do not have any limiting effect
on the scope of each element identified by way of example by such reference signs.
1. Cooling device, particularly for the drum bearings of laundry driers, comprising
a frame (2,2a) supporting said drum (3) by means of bearings (4a,4b,4c,4d), characterized
in that at least one air passage (8,9,13,17,18) is providcd at each of said bearings
for air coming from the outside, said air being adapted to cool said bearings.
2. Cooling device, according to claim 1, characterized in that said drum (3) comprises
at least one pivot (7,7a,12,16) associated to said bearing fixed to said frame by
means of a support (6,10,15).
3. Cooling device, according to claim 1 or 2, characterized in that said bearing is
a rolling bearing (4c).
4. Cooling device, according to one or more of the preceeding claims, characterized
in that said bearing is a plain bearing (4a,4b,4d).
5. Cooling device, according to one or more of the preceeding claims, characterized
in that said pivot (7a,12,16) is hollow for a passage of air from the outside to the
inside of said drier, for cooling said bearing.
6. Cooling device, according to one or more of the preceeding claims, characterized
in that said support (15) of said bearing is drilled for a passage of air from the
outside to the inside of said drier, for cooling said bearing.