EP2580527B1

EP2580527B1 - An oven

Info

Publication number: EP2580527B1
Application number: EP11725066.2A
Authority: EP
Inventors: Davut Ayhan Serabatir; Murat Mamatoglu
Original assignee: Arcelik AS
Current assignee: Arcelik AS
Priority date: 2010-06-09
Filing date: 2011-06-09
Publication date: 2016-05-04
Anticipated expiration: 2031-06-09
Also published as: WO2011154475A1; EP2580527A1

Description

The present invention relates to an oven wherein the noise originating from the motor is reduced.
In domestic type ovens, for example in built-in ovens, fans are used for providing homogenous heat distribution by the circulation of the hot air in the heating chamber and performing heat transfer by forced convection and cooling of the electronic devices inside the oven. The fan providing the hot air circulation in the heating chamber is mounted on the rear wall of the casing, which surrounds the heating chamber situated inside the main body of the oven, is driven by a motor and the high amplitude vibrations generated while the motor operates cause noise. The motor is secured to a motor supporting plate mounted on the rear wall of the casing and the vibrational movements of the motor are transmitted to the motor supporting plate and to the casing from there. The high amplitude vibrations of the motor cause the casing rear wall to operate as a diaphragm and to generate structural noise.
In the state of the art Japanese Patent Document No JP59027136 , a heating cooker is described, wherein the noise originating from the motor is reduced. The fixing material fitment, whereto the motor is connected, is joined to the insulating board by means of a spaced vibration absorbing cushion having an elastic structure.
In the state of the art Patent Document No. US5990467 , in a microwave oven, the motor actuating the blower fan that cools the microwave devices being mounted on the body rear wall by means of a fixing rod is explained.
In the state of the art International Patent Application No. WO2009083358 , an oven is described wherein the fan motor vibrations transmitted to the heating chamber is reduced by means of the leaf springs disposed between the motor lugs and the mounting plate.
WO 2009/083358 A2 discloses an oven of the kind explained above, wherein a mounting plate is mounted on the rear wall of a heating chamber in the oven. The mounting plate provides the fan motor to be connected to the exterior of the heating chamber rear wall. The mounting plate supports leaf springs on which lugs of the motor are mounted.
JP 2003/206987 A discloses a damper for base isolation for protecting a building from an earthquake. In one embodiment, the damper has an approximate circular form with two arms extending therefrom.
EP 1 589 250 A1 relates to a spring having particular elastic properties, and the spring is composed of two spring elements arranged in series. The spring elements have different properties in order to provide for particular properties of the resulting spring composed of these spring elements.
The aim of the present invention is the realization of an oven wherein the noise originating from the motor driving the fan, which provides the hot air circulation in the heating chamber, is reduced.
The oven realized in order to attain the aim of the present invention, explicated in the first claim and the respective claims thereof, comprises a fan that provides hot air to be circulated in the heating chamber wherein the cooking process is performed. The fan is driven by a motor, which is mounted behind the heating chamber rear wall and therefore not affected by the heat inside the heating chamber. The holder supporting the motor is mounted to the mounting plate that provides the motor to be secured to the rear wall of the heating chamber.
The oven of the present invention comprises more than one damper that provides the connection between the holder and the mounting plate. The damper comprises a first fixing surface providing it to be attached to the holder, a second fixing surface extending parallel to the first fixing surface and providing the latter to be mounted the mounting plate, a curve remaining between the first fixing surface and the second fixing surface, and a wall situated between the curve and the first fixing surface that narrows the distance between the first fixing surface and the second fixing surface. The curve is in bend form. The wall extends outwards from the first fixing surface in the direction of the shaft axis. Together the curve and the wall combine the first fixing surface and the second fixing surface. With vibrational motion of the motor, the damper stretches both in the direction of shaft axis by means of the curve and the wall. With this bi-directional stretching motion of the damper, the vibrational movements of the motor both in directions parallel to the mounting plate and also in the direction of the shaft axis are dampened.
In the present invention, the wall extends almost perpendicularly to the first fixing surface. Thus, the ability of the wall to stretch in the radial direction during vibrations generated by the motor in the radial direction and to dampen these vibrations is improved.
The width of the curve in the direction of the shaft axis is greater than the vertical distance between the first fixing surface and the second fixing surface. Accordingly, dampening of the axial vibrations especially originating from the motor is improved.
In an embodiment of the present invention, the curve is farther away from the fixing surfaces in the radial direction with respect to the shaft axis. The fixing surfaces contact the holder and the mounting plate and the curve extends outwards in the radial direction with respect to the shaft axis. The wall and the upper surface of the curve do not contact the holder and the mounting plate. The holder and the mounting plate are brought closer to each other by means of the curve and the wall being situated in front of the holder in the radial direction with respect to the shaft axis. The volume of the heating chamber used effectively is increased by bringing the holder and hence the motor closer to the mounting plate.
In another embodiment of the present invention, the second fixing surface is fastened to the mounting plate so as to extend towards under the first fixing surface. Thus, the first fixing surface is prevented from bumping into the mounting plate during high amplitude vibrations of the motor. The first fixing surface impacts to the second fixing surface during vibrations made by the motor in the direction of the shaft axis and noise generation in the heating chamber is prevented.
In another embodiment of the present invention, the damper comprises a step situated after the second fixing surface, having level of difference between itself and the second fixing surface and that increases the width of the damper in the radial direction with respect to the shaft axis. The vibration dampening capacity of the damper is determined by adjusting the dimensions of the step shaped as boarding-step during the design of the damper.
In an embodiment of the present invention, the depth of the second fixing surface is less than the depth of the damper. During assembly of the damper, the second fixing surface is seated in the housings arranged on the mounting plate. The depth of the damper is increased onwards from the end of the second fixing surface and the damper is provided to be strengthened particularly around the step thereby preventing too much stretching in this region.
In an embodiment of the present invention, at least one cut-out is provided on the wall. The flexibility of the wall is increased by means of the cut-out.
In another embodiment of the present invention, the damper is produced from polyamide. The performance of the damper is enhanced since polyamide is a material that is resistant to heat and plastic deformations.
In another embodiment of the present invention, the damper is produced from spring steel.
In another embodiment of the present invention, the damper comprises two screw holes, one arranged on the first fixing surface and one on the second fixing surface, providing the damper to be attached to the holder and the mounting plate respectively.
With the damper of the present invention, the vibrations generated during operation of the motor, both in direction of the motor shaft and in the radial direction with respect to the shaft axis are absorbed. Consequently, customer satisfaction is provided by preventing generation of noise in the heating chamber.
The oven realized in order to attain the aim of the present invention is illustrated in the attached figures, where:

Figure 1 - is the sideways schematic view of an oven.
Figure 2 - is the perspective view of the motor, the holder and the dampers.
Figure 3 - is the perspective view of the damper related to an embodiment of the present invention.
Figure 4 - is the perspective view of a damper from a different viewpoint.
Figure 5 - is the front view of a damper.

The elements illustrated in the figures are numbered as follows:

1. Oven
2. Heating chamber
3. Fan
4. Rear wall
5. Motor
6. Holder
7. Mounting plate
8. Damper
9., 109. Fixing surface
10. Curve
11. Wall
12. Step
13. , 113. Screw hole
14. Opening
15. Cut-out

The oven (1) comprises a heating chamber (2) wherein the cooking process is performed, a fan (3) providing hot air to be circulated in the heating chamber (2), a rear wall (4) that covers the rear side of the heating chamber (2), a motor (5) mounted outside the rear wall (4) and perpendicular to the rear wall (4) in the direction of the shaft axis (E), providing the fan (3) inside the heating chamber (2) to be rotated, a holder (6) on which the motor (5) is secured, a mounting plate (7) mounted outside the rear wall (4) whereto the holder (6) is fastened (Figure 1).
The oven (1) of the present invention comprises more than one damper (8) having

a first fixing surface (9) whereto the holder (6) is fastened,
a second fixing surface (109), extending parallel to the first fixing surface (9) such that a certain distance is kept between the first fixing surface (9) and the second fixing surface (109) whereto the mounting plate (7) is fastened,
a curve (10) disposed between the first fixing surface (9) and the second fixing surface (109) and
at least one wall (11) situated between the first fixing surface (9) and the second fixing surface (109) that brings the first fixing surface (9) and the second fixing surface (109) closer to each other in the shaft axis (E)

(Figure 2, Figure 3, Figure 4 and Figure 5).
The fixing surfaces (9, 109) are flat and the base of the first fixing surface (9) contacts the holder (6) while the base of the second fixing surface (109) contacts the mounting plate (7). The fixing surfaces (9, 109) extend parallel to each other in the radial direction with respect to the shaft axis (E) such that there is a certain distance there between. The curve (10) and the wall (11) situated after the curve (10) serve to combine the first fixing surface (9) and the second fixing surface (109). The cross section of the damper (8) in the shaft axis (E) direction is shaped like an almost closed curve. The damper (8) is fastened to the holder (6) preferably from three points. The angles between the dampers (8) with respect to the shaft axis (E) are almost equal to each other (Figure 2).
The vibrations generated during operation of the motor (5), both in the direction of the shaft axis (E) and in the direction vertical to the shaft axis (E) affect the first fixing surface (9) whereto the holder (6) is fastened. By means of the curve (10), the vibrations affecting on the first fixing surface (9) in the direction of the shaft axis (E) are dampened. The wall (11) dampens the vibrations affecting on the first fixing surface (9) in the direction vertical to the shaft axis (E). Thus, the noise level originating from the motor (5) in the heating chamber (2) is decreased by dampening the vibrations of the motor (5) both in the direction of the shaft axis (E) and in the direction perpendicular to the shaft axis (E) by means of the damper (8). The dimensions of the curve (10) and the wall (11) determine the vibration dampening ability of the damper (8). The wall (11) furthermore provides the distance between the holder (6) and the mounting plate (7) to decrease by bringing the second fixing surface (109) closer to the first fixing surface (9) (Figure 3, Figure 4 and Figure 5).
In an embodiment of the present invention, the curve (10) remains farther away from the fixing surfaces (9, 109) in the radial direction with respect to the shaft axis (E) (Figure 2). The damper (8) is fastened to the mounting plate (7) and the holder (6) such that the curve (10) remains in front of the motor (5) in the radial direction with respect to the shaft axis (E). The distance between the mounting plate (7) and the holder (6) is provided to be decreased by means of the curve (10) remaining farther away from the fixing surfaces (9, 109) in the radial direction with respect to the shaft axis (E). Consequently, the increase in length of the shaft due to utilization of the damper (8) is prevented. On the other hand, increasing the effectively used heating chamber (2) volume is made possible by gaining space.
In another embodiment of the present invention, the wall (11) extends almost perpendicularly to the first fixing surface (9) (Figure 3, Figure 4 and Figure 5). The height of the wall (11) in the direction of the shaft axis (E) serves as the moment arm for the forces exerted by the holder (6) on the first fixing surface (9) and by stretching in the radial direction, dampens the vibrations generated in this direction. The height of the wall (11) is determined depending on the magnitude of vibrations originating from the motor (5) and the elasticity coefficient of the material from which the damper (8) is produced.
In another embodiment of the present invention, the width (d1) of the curve (10) in the direction of the shaft axis (E) is greater than the vertical distance (d2) between the first fixing surface (9) and the second fixing surface (109) (Figure 5). Accordingly, the vibrations generated by the motor (5) particularly in the direction of the shaft axis (E) are dampened effectively.
In another embodiment of the present invention, the second fixing surface (109) extends towards under the first fixing surface (9) in the direction of the shaft axis (E) such that a certain distance remains there between, with at least some portion thereof being inwards from the level of the first fixing surface (9). Accordingly, the first fixing surface (9) impacts the second fixing surface (109) instead of the mounting plate (7) during high magnitude vibrations generated by the motor (5) in the direction of the shaft axis (E). Thus, generation of loud noise is prevented by avoiding the mounting plate (7) from impacting the rear wall (4).
In another embodiment of the present invention, the damper (8) comprises a step (12), that is disposed between the second fixing surface (109) and the curve (10), that forms a level difference between the curve (10) and the second fixing surface (109) such that the second fixing surface (109) remains below. The width of the damper (8) in the radial direction with respect to the shaft axis (E) is increased by means of the step (12). Thus, the second fixing surface (109) is provided to be seated in the housings situated on the mounting plate (7). Consequently, assembly of the damper (8) to the mounting plate (7) is performed more easily. Furthermore, the dimensions of the damper (8) can be adjusted by adjusting the dimensions of the step (12) and thus the damper (8) is provided to dampen the vibrations with the desired amplitude.
In another embodiment of the present invention, the damper (8) comprises at least one cut-out (15) disposed on the wall (11). Thus, the flexibility of the wall (11) is increased and its ability to dampen the vibrations in the radial direction with respect to the shaft axis (E) is increased.
In another embodiment of the present invention, the depth of the second fixing surface (109) is less than the depth of the curve (10). Since the depth of the second fixing surface (109) is determined according to the depth of the housings disposed on the mounting plate (7), the depth of the curve (10) is increased and kept larger than the depth of the second fixing surface (109). Thus, the rigidity of the curve (10) is increased in the vicinity of the step (12) thereby providing the step (12) not to stretch too much.
In another embodiment of the present invention, the damper (8) is produced from polyamide. Since polyamide is a material resistant to high temperature, it is not adversely affected by the heat inside the heating chamber (2). Since polyamide is also a material with high strength, the problem of the damper (8) being fatigued and broken in the course of time is prevented.
In another embodiment of the present invention, the damper (8) is produced from spring steel. Since spring steel is a material with high resistance to high temperature and impacts, the damper (8) is prevented from burning, melting or being subjected to plastic deformation.
In another embodiment of the present invention, the damper (8) comprises a first screw hole (13) situated on the first fixing surface (9) and providing the damper (8) to be fastened to the holder (6) and a second screw hole (113) situated on the second fixing surface (109) and providing the damper (8) to be fastened to the mounting plate (7). Thus, the assembly of the damper (8) to the holder (6) and to the mounting plate (7) is performed easily by means of screwing, etc.
In another embodiment of the present invention, the damper (8) comprises an opening (14) disposed on the curve (10) and aligned with the second screw hole (113), large enough for the screw head to pass, that is fastened to the mounting plate (7) from the screw hole (113). The damper (8) is first mounted to the holder (6) and afterwards is mounted on the mounting plate (7) by means of a screwdriver inserted through the opening (14).
In the oven (1) of the present invention, motor (5) originated noise is provided to be decreased by diminishing the vibrations transmitted from the motor (5) to the mounting plate (7) and from the mounting plate (7) to the rear wall (4) of the heating chamber (2).
It is to be understood that the present invention is not limited to the embodiments disclosed above and a person skilled in the art can easily introduce different embodiments. These should be considered within the scope of the protection postulated by the claims of the present invention.

Claims

An oven (1) comprising a heating chamber (2) wherein the cooking process is performed, a fan (3) providing hot air to be circulated in the heating chamber (2), a rear wall (4) that covers the rear side of the heating chamber (2), a motor (5) mounted outside the rear wall (4) and perpendicular to the rear wall (4), in the direction of the shaft axis (E), providing the fan (3) to be rotated inside the heating chamber (2), a holder (6) whereon the motor (5) is secured, a mounting plate (7) mounted outside the rear wall (4), whereto the holder (6) is fastened, and more than one damper (8) having a first fixing surface (9) whereto the holder (6) is attached, - a second fixing surface (109), extending parallel to the first fixing surface (9) such that a certain distance is kept between the first fixing surface (9) and the second fixing surface (109), whereto the mounting plate (7) is attached, - a curve (10) disposed between the first fixing surface (9) and the second fixing surface (109) characterized by - at least one wall (11) disposed between the first fixing surface (9) and the curve (10) that brings the first fixing surface (9) and the second fixing surface (109) closer to each other in the shaft axis (E), wherein the wall (11) extends almost perpendicularly to the first fixing surface (9) and wherein the width (d1) in the direction of the shaft axis (E) of the curve (10) is greater than the vertical distance (d2) between the first fixing surface (9) and the second fixing surface (109).
An oven (1) as in Claim 1, characterized by the curve (10) that remains farther away from the fixing surfaces (9, 109) in the radial direction with respect to the shaft axis (E).
An oven (1) as in Claim 1 or 2, characterized by the second fixing surface (109) that extends towards under the first fixing surface (9) in the direction of the shaft axis (E) such that a certain distance remains there between, with at least some portion thereof being inwards from the level of the first fixing surface (9).
An oven (1) as in any one of the above Claims, characterized by the damper (8) comprising a step (12), that remains between the second fixing surface (109) and the curve (10), forming a level difference between the curve (10) and the second fixing surface (109) such that the second fixing surface (109) remains below.
An oven (1) as in any one of the above Claims, characterized by the damper (8) that comprises at least one cut-out (15) disposed on the wall (11).
An oven (1) as in any one of the above Claims, characterized by the second fixing surface (109) the depth of which is less than the depth of the curve (10).
An oven (1) as in any one of the above Claims, characterized by the damper (8) that is produced from polyamide.
An oven (1) as in any one of claims 1 to 6, characterized by the damper (8) that is produced from spring steel.
An oven (1) as in any one of the above Claims, characterized by the damper (8) that comprises a first screw hole (13) situated on the first fixing surface (9) and providing the damper (8) to be fastened to the holder (6) and a second screw hole (113) situated on the second fixing surface (109) and providing the damper (8) to be fastened to the mounting plate (7).
An oven (1) as in Claim 9, characterized by the damper (8) that comprises an opening (14) disposed on the curve (10) and aligned with the second screw hole (113), large enough for the screw head to pass, that is fastened to the mounting plate (7) from the screw hole (113).