Home laundry drier

Abstract

 A laundry drier (1) having an outer casing (2); a rotary drying drum (3) for housing laundry for drying, and which is mounted inside the casing (2) to rotate freely about a respective longitudinal axis (L); an electric motor (4) for rotating the drying drum (3) about the longitudinal axis (L); and at least one centrifugal cooling fan (12) mounted inside the casing (2) to rotate freely about an axis of rotation (R); the laundry drier (1) having a drive (13), which connects the rotary drying drum (3) to the centrifugal cooling fan (12) to transmit rotation of the drying drum (3) to the centrifugal cooling fan (12), so as to rotate the centrifugal cooling fan (12).

Description

[0001] The present invention relates to a laundry drier, to which the following description refers purely by way of example.

[0002] As is known, a rotary-drum laundry drier substantially comprises a substantially parallelepiped-shaped outer casing; a laundry drying drum mounted inside the casing to rotate axially about a substantially horizontal axis, and positioned facing a laundry loading-unloading opening formed in the front face of the casing; a door hinged to the front face of the casing to rotate to and from a work position closing the opening in the front face and sealing the laundry drying drum; and an electric motor for rotating the laundry drying drum about its longitudinal axis inside the drying tub.

[0003] Rotary-drum laundry driers of the above type also feature a hot-air generator for generating and circulating inside the drying drum hot, dry air, which flows through the drum to rapidly dry the laundry inside.

[0004] In some recently marketed laundry driers, the hot-air generator operates in the same way as a heat pump, circulates the same air continually inside the drying drum, and continually removes surplus moisture from the hot air issuing from the drying drum after flowing over the laundry inside.

[0005] More specifically, the hot-air generator comprises a cooling fluid compression device, or so-called compressor, located inside the casing, just beneath the drying drum and adjacent to the front wall of the casing, and which transfers heat from one fluid to another using an intermediate gaseous cooling fluid, which is subjected to a closed thermodynamic cycle to rapidly cool, and so reduce the moisture content, of the air from the drying drum.

[0006] The hot-air generator also comprises a centrifugal fan, for cooling the compression device, which is located between the front wall of the drier and the compression device, and is driven by an electric motor controlled by an electronic control board.

[0007] To prevent accidental electric contact on the part electric motor of the user, the above rotary-drum laundry driers are also known to normally comprise a outer casing which excludes the possibility of any accidental electric contact on the motor of the user, but pose the drawback of taking up considerable space inside the casing of the rotary-drum laundry drier.

[0008] A major goal, in fact, in current drier design is to optimize use of the space inside the casing to make room for other performance-improving devices, as on other drier models, while at the same time reducing the number of electric/electronic components employed, to reduce the manufacturing cost and energy consumption of the drier.

[0009] It is an object of the present invention to provide a laundry drier designed to increase the space available inside the casing for additional component parts, and which provides for reducing the manufacturing cost and energy consumption as compared with known driers.

[0010] According to the present invention, there is provided a laundry drier as claimed in Claim 1 and preferably, though not necessarily, in any one of the Claims depending directly or indirectly on Claim 1.

[0011] A non-limiting embodiment of the present invention will be described by way of example with reference to the accompanying drawings, in which:

Figure 1 shows a schematic side view, with parts removed for clarity, of a rotary-drum laundry drier in accordance with the teachings of the present invention;

Figure 2 shows a schematic front view, with parts removed for clarity, of the Figure 1 drier, showing the drive connecting the drying drum to the compression device centrifugal cooling fan;

Figure 3 shows a schematic side view, with parts removed for clarity, of an alternative embodiment of a rotary-drum laundry drier;

Figure 4 shows a front view, with parts removed for clarity, of the Figure 3 drier, showing the drive connecting the drying drum to the compression device centrifugal cooling fan.

[0012] Number 1 in Figure 1 indicates as a whole a home laundry drier substantially comprising a preferably, though not necessarily, parallelepiped-shaped outer casing 2; a laundry drying drum 3 for housing the laundry to be dried, and which is mounted inside casing 2 to rotate freely about a respective axis of rotation L, and is positioned directly facing a laundry loading-unloading opening 2a formed in the front face of casing 2.

[0013] Drier 1 also comprises an electric motor 4 for rotating drying drum 3 about its axis of rotation L; and a door (not shown) hinged to the front face of casing 2 to rotate to and from a work position closing opening 2a in the front face and sealing drying drum 3.

[0014] More specifically, in the Figure 1 example, drying drum 3 has a circular loading hatch 3a facing opening 2a, and comprises an annular flange 5 surrounding loading hatch 3a, and the outer edge of which rests on a number of supporting rollers 6 fitted to casing 2.

[0015] More specifically, rollers 6 are fitted to casing 2 to rotate freely about respective axes as drying drum 3 rotates, and are designed to keep the axis of rotation L of the drum in the set, i.e. horizontal, position.

[0016] Drier 1 also comprises a closed-circuit, hot-air generator 7 housed inside casing 2 and designed to circulate inside drying drum 3 hot, dry air, which flows over and rapidly dries the laundry inside the drum.

[0017] More specifically, hot-air generator 7 operates in the same way as a heat pump, by transferring heat from one fluid to another using an intermediate gaseous cooling fluid subjected to a closed thermodynamic cycle - the thermodynamic principles of which are well known and not described in detail - and provides for drawing air gradually out of drying drum 3; extracting surplus moisture from the hot air drawn from drying drum 3; heating the dried air to a predetermined temperature, normally higher than the temperature of the air inside drying drum 3; and, finally, feeding the hot, dried air back into drying drum 3 and over the laundry again inside the drum to dry it rapidly.

[0018] In other words, hot-air generator 7 continually dries and heats the air inside drying drum 3 to rapidly dry the laundry inside the drum.

[0019] With reference in particular to Figure 1, hot-air generator 7 substantially comprises an air recirculating manifold 8 connected at one end to a perforated rear wall of drying drum 3 to feed hot air into drying drum 3, and, at the other end, to a front portion of drying drum 3, from which the moist air inside the drum is drawn.

[0020] Hot-air generator 7 also comprises a cooling fluid compression device or so-called compressor 9, where the cooling fluid is subjected to compression (e.g. adiabatic compression) so that the pressure and temperature of the cooling fluid from compression device 9 are considerably higher than the pressure and temperature of the cooling fluid to the compression device.

[0021] With reference to Figure 1, hot-air generator 7 also comprises a first heat exchanger or so-called evaporator 10 located along recirculating manifold 8 and connected to compression device 9, so that the cooling fluid absorbs heat from the air issuing from drying drum 3, and, at the same time, the surplus moisture in the air is condensed.

[0022] Hot-air generator 7 also comprises a second heat exchanger or so-called condenser 11 located along recirculating manifold 8 and connected to compression device 9 to receive the cooling fluid and release heat to the airflow into drying drum 3.

[0023] With reference to Figure 1, drier 1 also comprises a centrifugal fan 12 mounted inside casing 2 to rotate freely about a respective axis R; and a drive 13, which connects drying drum 3 to centrifugal fan 12 to transmit rotation of drying drum 3 to, and so rotate, centrifugal fan 12.

[0024] More specifically, in the Figure 1 example, fan 12 is located adjacent to the front wall of casing 2, directly facing compression device 9, i.e. the compressor, so as to cool compression device 9, and is fitted to a drive shaft 14 mounted for rotation on a supporting member 15 fixed to the base of casing 2.

[0025] With reference to Figures 1 and 2, drive 13 comprises a drive belt 17 looped about drying drum 3 and drive shaft 14 of centrifugal fan 12.

[0026] In the Figure 1 and 2 example, drive 13 also comprises, in addition to drive belt 17, a pulley 16 fitted to drive shaft 14 of fan 12, and drive belt 17 is looped about pulley 16 and annular flange 5 of drying drum 3, so as to transmit rotation of drying drum 3 to fan 12 and so rotate fan 12 about axis R.

[0027] In an alternative embodiment shown in Figures 3 and 4, as opposed to being looped about annular flange 5, drive belt 17 of drive 13 is looped about one of rollers 6 supporting annular flange 5, so as to transmit the rotation of roller 6, produced by rotation of drying drum 3, to pulley 16 of fan 12.

[0028] More specifically, the drive belt 17 of drive 13 can be looped about one external portion of the roller 6 which does not support the drying drum 3, or about a pulley 20 which is fitted to roller 6 so as to transmit the rotation of roller 6, produced by rotation of drying drum 3, to pulley 16 of fan 12.

[0029] Operation of drier 1 will be clear from the above description, with no further explanation required.

[0030] The advantages of using drive 13 to transmit rotation of drying drum 3 to cooling fan 12 of compression device 19 are obvious: the electric motor normally used to drive the cooling fan of the compression device is eliminated, thus reducing the manufacturing cost of the drier, reducing energy consumption, and, at the same time, making more room available inside the casing for additional devices.

[0031] Clearly, changes may be made to drier 1 as described herein without, however, departing from the scope of the present invention.

Claims

1. A laundry drier comprising an outer casing (2); a rotary drying drum (3) for housing laundry for drying, and which is mounted inside said casing (2) to rotate freely about a respective longitudinal axis (L); an electric motor (4) for rotating said drying drum (3) about the longitudinal axis (L); and at least one centrifugal cooling fan (12) mounted inside said casing (2) to rotate freely about an axis of rotation (R); said laundry drier (1) being characterized by comprising drive means (13) for transmitting rotation of the drying drum (3) to said centrifugal fan (12), so as to rotate the centrifugal fan (12).

2. A laundry drier as claimed in Claim 1, wherein said drive means (13) comprise a drive belt (17) looped about said drying drum (3) and about a drive shaft (14) of said centrifugal fan (12).

3. A laundry drier as claimed in Claim 2, wherein said drying drum (3) comprises an annular flange (5) resting on at least one supporting roller (6) mounted to rotate freely on said casing (2) and supporting said drying drum (3); said drive belt (17) being looped about said annular flange (5) and about said drive shaft (14) of said centrifugal fan (12).

4. A laundry drier as claimed in Claim 3, wherein said centrifugal fan (12) comprises a pulley (16) fitted to said drive shaft (14); said drive belt (17) being looped about said annular flange (5) and about said pulley (16) of said centrifugal fan (12).

5. A laundry drier as claimed in Claim 1, wherein said drive means (13) comprise a drive belt (17); and wherein said drying drum (3) comprises an annular flange (5) resting on at least one supporting roller (6) mounted to rotate freely on said casing (2) and supporting said drying drum (3); said drive belt (17) being looped about said supporting roller (6) and about said drive shaft (14) of said centrifugal fan (12).

6. A laundry drier as claimed in Claim 5, wherein said centrifugal fan (12) comprises a pulley (16) fitted to said drive shaft (14); said drive belt (17) being looped about said supporting roller (6) and about said pulley (16) of said centrifugal fan (12).

7. A laundry drier as claimed in any one of the foregoing Claims, and comprising hot-air generating means (7) for circulating hot air inside the drying drum (3), and which comprise a compression device (9) for compressing a cooling fluid, and at least one heat exchanger (10, 11) connected to said compression device (9) to receive said cooling fluid; said centrifugal fan (12) cooling said compression device (9).

Drawing