Support and sealing assembly for the drum of a laundry dryer

Description

[0001] The present invention generally relates to a laundry dryer provided with a rotatable drum adapted to contain the laundry to be dried and supported in a sealing manner within an outer housing of the machine.

[0002] As generally known, conventional laundry drying machines are provided with a drum adapted to permit the passage of a drying air flow therethrough and formed of a cylindrical peripheral wall and two end walls, a forward and a rearward one, each of which may be supported within the housing of the machine. In particular, the forward end wall is formed with a circular opening surrounded by a raised rim portion adapted to be rotatably received in a circular support element secured to the front wall of the housing and provided on its outer periphery with fixed roller and/or frictional bearing elements, for example rollers, bearing shells or the like formed of a low-friction material.

[0003] Between the front end wall of the drum and the annular support there is usually (see, for example, GB-A-2095384) disposed a sealing gasket formed of felt of another low-friction material capable of being resiliently compressed in the radial direction into engagement with the edge of the drum by means of annular elements formed of rubber or a synthetic foam material so as to prevent the circulated hot air from escaping from the drum towards the housing of the machine. Due to the inevitable friction with the front end wall of the drum, the sliding support or bearing elements are worn, at times even in a non-uniform manner, resulting in a progressively irregular rotation of the drum. In this case there is no longer a continuous contact between the edge portion of the drum and the bearing elements, resulting in a non-uniform contact also of the sealing elements, permitting the drying air to escape from the drum so as to correspondingly reduce the thermal efficiency of the machine. In addition, the irregular contact may result in the laundry getting caught between the drum and the bearing elements, with the resultant danger of the laundry being damaged. It is also to be noted that the resilient annular elements made of rubber or a foamed synthetic material and used for radially biasing the sealing elements into engagement with the surface of the drum may be unable to produce a sufficient oscillation of the sealing elements forthe latter to remain in contact with the irregularly rotating drum. Also, in the presence of particularly humid environmental conditions, the material of the annular biasing elements may be subjected to degradation so as to lose the resilient properties required for functioning properly. Also to be taken into account are the manufacturing tolerances between the stationary elements and the movable parts as well as a possible overloading of the drum with laundry to be dried which may prejudice the regular rotation of the drum and thus the proper function of the supporting and bearing components.

[0004] In view of the above, it is an object of the present invention to provide a laundry drying machine of the type having a rotatable drum, wherein the components employed for mounting the drum are capable of compensating any play caused by wear and/or by manufacturing tolerances of the components subjected to frictional wear.

[0005] Another object of the invention is the provision of a laundry drying machine of the type defined above provided with sealing means which are not readily degraded and designed to ensure a continuous and reliable contact with an associated portion of the drum, so as to provide an air-tight seal.

[0006] These and other objects are attained according to the invention by a support and sealing assembly for the drum of a laundry dryer comprising a housing in which said drum for containing the laundry to be dried is mounted for rotation about a horizontal axis, said drum having a cylindrical peripheral wall, a rear end wall mounted within the housing of the machine, and a front end wall formed with a central opening supported in a corresponding collar disposed interiorly of said housing and provided with bearing means for rotatably mounting said drum and sealing means for retaining the drying air stream passing through said drum, said support and sealing assembly (known from GB-A-2095384) being characterized in that said support collar for said front end wall of said drum comprises a portion projecting radially into said opening of said drum and adapted to accommodate fixed bearing means and resilient bearing means oscillating in the radial direction of said drum, and a portion adapted to accommodate air sealing means displaceable in a direction parallel to the axis of said drum, said bearing means and said sealing means being adapted to cooperate respectively with a horizontal rim portion and a rearwardly curved end portion of said drum front end wall.

[0007] Further characteristics and advantages of the invention will become more clearly evident from the following description, given by way of a nonlimiting example with reference to the accompanying drawings, wherein:

Fig. 1 shows a diagrammatical perspective front view of a laundry dryer provided with a support and sealing assembly according to the invention,

Fig. 2 shows a partially sectioned front elevational view of the rotatable mounting of the drum front end wall, and

Fig. 3 shows an enlarged cross-sectional view taken along this line III-III in Fig. 2.

[0008] A laundry dryer generally indicated at 4 in Fig. 1 is provided with a support and sealing assembly according to the invention, and itself comprises an outer housing 5 with a cylindrical drum 6 mounted therein for rotation about a horizontal axis. Drum 6 is formed of a peripheral wall 7 and two end walls 8, 9, a front end wall 8 being of annular shape and formed with a central opening 10 corresponding to the charging window of laundry dryer 4, and a rear end wall 9, both end walls being rotatably supported within housing 5. In particular, rear end wall 9 may be provided with a central stub axle (not shown) cooperating with bearing means (likewise not shown) secured to the interior rear wall of housing 5. Opening 10 of front end wall 18 is surrounded by an upstanding rim projecting towards the front wall of housing 5 and having a horizontally extending rim portion 11 terminating in a rearwardly curved end portion 12.

[0009] Secured to the interior front wall surface of housing 5 at a position facing the rim of opening 10 of front end wall 8 is a circular support collar 13 having a configuration similar to the letter "S" in cross-section as shown in Fig. 3.

[0010] This radial cross-sectional configuration of collar 13 is composed of an inner portion 14 disposed interiorly of opening 10 of front end wall 8 at a location underlying the rectilinear rim portion 11, and an outer portion 15 located opposite rearwardly curved end portion 12 of the above mentioned rim. Inner portion 4 of collar 13 accommodates three bearing members 16, 17 and 18 of a low-friction material (Fig. 2) for rotatably retaining therebetween rim portion 11 of drum 6.

[0011] Two such bearing members 16 and 17 are located at the upper arcuate portion of collar 13 in symmetrical relationship with respect to the vertical axis x-x of drum 6, while the third bearing member 18 is disposed at the lower portion of collar 13 in alignment with axis x-x of drum 6.

[0012] Lower bearing member 18 is of the fixed type usually employed in laundry dryers, while the two upper bearing members 16 and 17 are mounted for resilient oscillation in a substantially radial direction within corresponding openings 19 formed in inner portion 14 of collar 13 opposite horizontal rim portion 11 of drum 6. Each upper bearing member 16, 17 is resiliently biased towards rim portion 11 of drum 6 by a pair of compression springs 20 disposed between the radially inner surface of the respective bearing member 16 or 17 and a seat 21 formed at the bottom of inner portion 14 of collar 13 as shown in Fig. 3. In addition, upper bearing members 16, 17 are formed with a projecting shoulder 22 adapted to seat on the interior rims of opening 19 for preventing the respective bearing member from escaping from support collar 13 as long as they are not retained therein by rim portion 11 of drum 6. The force of springs 20 is suitably calculated for compensating the compressive loads exerted by the weight of the drum and the laundry contained therein and by the reactive force of a transmission belt extending between a motor 23 and drum 6 of the laundry dryer.

[0013] In the laundry dryer according to the invention, air-tight sealing of drum 6 adjacent front end wall 8 is accomplished by means of an annular element 24 (Fig. 3) made of felt or a similar material and having an inverted C-shaped cross-sectional configuration, the free end portions of which are secured to a circular support 25 slidingly received in a horizontal direction within outer collar portion 15 as shown in Fig. 3.

[0014] The insertion of slidable support 25 into collar portion 15 is facilitated by chamfered surface portions 27 formed along the edge 26 of collar 13. On its side facing towards the front of laundry dryer 4, circular support 25 is provided with a plurality of horizontally projecting pins 29 each surrounded by a compression spring 30 for biasing support 25 towards the rim of drum 6 so as to compressively engage annular felt element 24 with rearwardly curved end portion 12 to the rim of drum 6.

[0015] For preventing support 25 from escaping from collar portion 15 under the biasing force of springs 30, edge 26 of collar 13 is formed with a plurality of inwards directed stop projections 28 adjacent chamfered surfaces 27 for retaining support 25.

[0016] From the above description it is evident that the laundry dryer according to the invention is superior to known laundry dryers of similar type as regards it efficiency and reliability in operation. The resilient bearing members 16 and 17 are effective to compensate the varying charging conditions and orientation of drum 6 so as to keep the latter aligned with its ideal axis of rotation in cooperation with the fixed lower bearing member 18 which has for its main function the centering of the rotating drum.

[0017] The upper bearing members 16, 17 are continually kept in contact with the rim of drum 6 by the combined action of the associated pairs of springs 20. In this manner they contribute equally to the support of the drum resulting in their being worn in a more uniform manner, whereby their useful life is extended.

[0018] In the described manner, the gap existing between the bearing surfaces of the bearing members and the rim of the drum is kept substantially constant over an extended period of time, whereby numerous causes for heat losses and for laundry being damaged are eliminated. In addition to the described advantages, the laundry dryer according to the invention derives further advantages from the employ of a spring-biased support for the air-tight sealing gasket, which support is not subjected to noticeable degradation and is capable of moving over a sufficient distance for reliably keeping the sealing gasket 24 in continuous contact with the end portion 12 of the rim of the drum 6. This particular feature in combination with the described configuration of the felt gasket ensure an effective air-tight seal even in the case of excessive manufacturing tolerances between stationary and moving components.

[0019] Finally to be underlined is the advantageous combination of supporting and sealing components acting in two directions perpendicular to one another. As a result, any wear of the radially acting supporting components will be of no consequence for the effectiveness of the axially acting sealing components.

Claims

1. A support and sealing assembly for the drum (6) of a laundry dryer (4) comprising a housing (5) in which said drum (6) for containing the laundry to be dried is mounted for rotation about a horizontal axis, said drum having a cylindrical peripheral wall (7), a rear end wall (9) mounted within the housing (5) of the machine, and a front end wall (8) formed with a central opening (10) supported in a corresponding collar (13) disposed interiorly of said housing and provided with bearing means (16,17,18) for rotatably mounting said drum (6) and sealing means for retaining the drying air stream passing through said drum (6), characterized in that said support collar (13) for said front end wall (8) of said drum (6) comprises a portion (14) projecting radially into said opening (10) of said drum and adapted to accommodate fixed bearing means (18) and resilient bearing means (16, 17) oscillating in the radial direction of said drum, and a portion (15) adapted to accommodate air sealing means (24) displaceable in a direction parallel to the axis of said drum (6), said bearing means (16, 17, 18) and said sealing means (24) being adapted to cooperate respectively with a horizontal rim portion (11) and a rearwardly curved end portion (12) of said drum front end wall (8).

2. A support and sealing assembly according to claim 1, characterized in that said bearing means (16, 17, 18) for said drum (6) comprises at least two bearing members (16, 17) located at the upper arcuate portion of said collar (13) in symmetric relationship with respect to the longitudinal axis of said drum (6), each said bearing member (16, 17) cooperating with at least one compression spring (20) capable of causing it to resiliently oscillate in a radial direction within a corresponding opening (19) formed in the respective portion (14), and a fixed bearing member (18) secured to the lower portion of said collar (13) in alignment with the longitudinal axis of said drum (6).

3. A support and sealing assembly according to claim 1 or 2, characterized in that said air sealing means comprises an annular element (24) formed of a low-friction material and having an inverted C-shape cross-sectional configuration, the two free end portions of which are secured to an annular support (25) mounted for horizontal sliding displacement in the respective portion (15) of said collar (13) and provided with a plurality of horizontal pins (29) carrying respective compression springs (30) adapted to resiliently bias said support (25) and said annular element (24) into engagement with the rearwardly curved end portion (12) of the rim of said drum (6).

Ansprüche

1. Halte- und Dichtungsanordnung für die Trommel (6) eines Wäschetrockners (4), enthaltend ein Gehäuse (5), in welchem die Trommel (6) zur Aufnahme der zu trocknenden Wäsche um eine horizontale Achse drehbar gelagert ist, welche Trommel eine zylindrische Umfangswand (7), eine hintere Stirnwand (9), die im Gehäuse (5) der Maschine gehalten ist, und eine vordere Stirnwand (8) aufweist, die mit einer Mittenöffnung (10) versehen ist, die in einem entsprechenden Kragen (13) gehalten ist, der im Innern des Gehäuses angeordnet und mit Lagerelementen (16, 17, 18) zum drehbaren Halten der Trommel (6) und mit Dichtungseinrichtungen zum Zurückhalten des durch die Trommel streichenden Trocknungsluftstroms versehen ist, dadurch gekennzeichnet, daß der Haltekragen (13) für die vordere Stirnwand (8) der Trommel (6) einen radial in die Öffnung (10) der Trommel vorstehenden Abschnitt (14) aufweist, der dazu eingerichtet ist, feste Lagerelemente (18) und elastische Lagerelemente (16, 17) aufzunehmen, die in der radialen Richtung der Trommel schwingen, und einen Abschnitt (15) enthält, der dazu eingerichtet ist, Luftdichtungseinrichtungen (24) aufzunehmen, die in einer Richtung parallel zur Achse der Trommel (6) verstellbar sind, welche Lagereinrichtungen (16, 17, 18) und Dichtungseinrichtungen (24) dazu geeignet sind, mit einem horizontalen Randabschnitt (11) bzw. einem nach hinten gebogenen Endabschnitt (12) der vorderen Trommelstirnwand (8) zusammenzuwirken.

2. Halte- und Dichtungsanordnung nach Anspruch 1, dadurch gekennzeichnet, daß die Lagereinrichtungen (16, 17, 18) für die Trommel (6) wenigstens zwei Lagerelemente (16, 17) aufweisen, die an dem oberen bogenförmigen Abschnitt des Kragens (13) in symmetrischem Verhältnis in bezug auf die Längsachse der Trommel (6) gelegen sind, wobei jedes der Lagerelemente (16, 17) mit wenigstens einer Druckfeder (20) zusammenwirkt, die in der Lage ist, es in einer radialen Richtung innerhalb einer entsprechenden Öffnung (19) elastisch oszillieren zu lassen, die in dem entsprechenden Abschnitt (14) ausgebildet ist, und ein festes Lagerelement (18) enthält, das an dem unteren Abschnitt des Kragens (13) in Ausrichtung mit der Längsachse der Trommel (6) befestigt ist.

3. Halte- und Dichtungsanordnung nach Anspruch 1 oder 2, dadurch gekennzeichnet, daß die Luftdichtungseinrichtung ein ringförmiges Element (24) enthält, das aus einem Material geringer Reibung besteht und eine umgekehrt C-förmige Querschnittsgestalt hat, deren zwei freie Endabschnitte an einem ringförmigen Träger (25) befestigt sind, der zur horizontal gleitenden Verstellung in dem entsprechenden Abschnitt (15) des Kragens (13) montiert ist und mit mehreren horizontalen Stiften (29) versehen ist, die jeweils Druckfedern (30) tragen, die dazu eingerichtet sind, den Träger (25) und das ringförmige Element (24) elastisch in Anlage an den nach hinten gebogenen Endabschnitt (12) des Randes der Trommel (6) vorzuspannen.

Revendications

1. Dispositif de support et d'étanchéité pour le tambour (6) d'une machine à sécher le linge (4) comportant un carter (5) dans lequel est monté le tambour (6) contenant le linge à sécher de façon qu'il puisse tourner autour d'un axe horizontal, ce tambour ayant une paroi périphérique cylindrique (7), une paroi terminale arrière (9) montée à l'intérieur du carter (5) de la machine, et une paroi terminale avant (8) formée avec une ouverture centrale (10) supportée dans un collier correspondant (13) disposé à l'intérieur du carter et équipé de moyens porteurs (16, 17, 18) pour assurer un montage rotatif du tambour (6) et de moyens d'étanchéité pour retenir le courant d'air de séchage traversant le tambour (6), caractérisé en ce que le collier support (13) pour la paroi terminale avant (8) du tambour (6) comporte une portion (14) se projetant radialement dans l'ouverture (10) du tambour et adaptée pour recevoir des moyens porteurs fixes (18) et des moyens porteurs élastiques (16, 17) oscillant dans la direction radiale du tambour, et une portion (15) adaptée pour recevoir des moyens d'étanchéité à l'air (24) pouvant être déplacés dans une direction parallèle à l'axe du tambour (6), ces éléments porteurs (16, 17, 18) et ces moyens d'étanchéité (24) étant adaptés pour coopérer respectivement avec une portion de rebord horizontale (11) et une portion terminale recourbée vers l'arrière (12) de la paroi terminale avant (8) du tambour.

2. Dispositif de support et d'étanchéité selon la revendication 1, caractérisé en ce que les moyens porteurs (16, 17, 18) pour le tambour (6) comportent au moins deux éléments porteurs (16, 17) disposés au niveau de la portion recourbée supérieure du collier (13) de façon symétrique par rapport à l'axe longitudinal du tambour (6), chacun de ces éléments porteurs (16, 17) coopérant avec au moins un ressort de compression (20) susceptible de la faire osciller élastiquement dans la direction radiale à l'intérieur d'une ouverture correspondante (19) formée dans la portion respective (14), et un élément porteur fixe (18) fixé sur la portion inférieure du collier (13) et aligné sur l'axe longitudinal du tambour (6).

3. Dispositif de support et d'étanchéité selon la revendication 1 ou la revendication 2, caractérisé en ce que les moyens d'étanchéité à l'air comportent un élément annulaire (24) en un matériau à bas coefficient de frottement et ayant en coupe transversale la configuration d'un C inversé, les deux portions terminales libres de ce C étant fixées sur un support annulaire (25) monté pour un déplacement coulissant horizontal dans la portion respective (15) du collier (13) et équipé d'une multiplicité de broches horizontales (29) portant des ressorts de compression respectifs (30) adaptés pour rappeler élastiquement le support (25) et l'élément annulaire (24) en prise avec la portion terminale recourbée vers l'arrière (12) du rebord du tambour (6).

Drawing