Electric cooking appliance equipped with a centrifugal cooling fan

Abstract

The electric cooking appliance (1) comprises a housing (3); a cooking vessel (5) disposed in the housing (3); a hot-air cooking device (13) comprising a heating fan (14); a rotary drive device (16) configured to drive the heating fan (14) in rotation; and an air-circulation cooling device configured to generate a cooling airflow capable of flowing at least in part in contact with the rotary drive device (16). The air-circulation cooling device comprising a centrifugal fan (21) having an impeller wheel (26) provided with a plurality of blades each having a pressure surface that is convex and a suction surface that is concave.

Description

Electric cooking appliance equipped with a centrifugal cooling fan

[0001] The present invention relates generally to an electric cooking appliance for cooking food products, and in particular to a hot air cooking appliance. State of the art

[0002] As is well known, a hot air cooking appliance includes:

[0003] - a housing including a receiving compartment,

[0004] - a cooking container placed, for example in a removable manner, in the receiving compartment and configured to receive food to be cooked,

[0005] - a hot air cooking device configured to generate a flow of hot air over the food received in the cooking container, the hot air cooking device comprising a heating fan configured to generate an airflow and a heating device configured to heat the airflow generated by the heating fan,

[0006] - a rotary drive device configured to rotate the heating fan around a fan rotation axis, and

[0007] - an air circulation cooling device configured to generate a cooling airflow capable of flowing at least partially in contact with the rotating drive device.

[0008] Advantageously, such an air circulation cooling device includes a centrifugal fan comprising:

[0009] - a crankcase defining a receiving volume and comprising at least one crankcase air inlet fluidly connected to the receiving volume and one crankcase air outlet fluidly connected to the receiving volume, and

[0010] - a paddle wheel located in the receiving volume and having a wheel rotation axis, the paddle wheel being equipped with several blades, each blade having an intrados and an extrados. Generally, the blades are made of folded metal and each extends in a plane.

[0011] This type of air circulation cooling system ensures a high airflow within the system, thus providing optimal cooling for the rotating drive mechanism, and in particular for the drive motor. Consequently, this configuration of the air circulation cooling system enhances the reliability of the aforementioned hot air cooking appliance.

[0012] However, the aforementioned type of air circulation cooling device generates significant noise, which can be detrimental to the user's comfort when using the cooking appliance, particularly during prolonged use of the cooking appliance.

[0013] The technical problem underlying the invention is therefore to provide an electric cooking appliance with a simple and reliable structure and which generates relatively less noise compared to electric cooking appliances of the prior art.

[0014] To this end, the present invention relates to an electric cooking appliance, such as a hot air cooking appliance, comprising:

[0015] - a housing including a receiving compartment,

[0016] - a cooking container placed, for example in a removable manner, in the receiving compartment and configured to receive food to be cooked,

[0017] - a hot air cooking device configured to generate a flow of hot air over the food received in the cooking container, the hot air cooking device comprising a heating fan configured to generate an airflow and a heating device configured to heat the airflow generated by the heating fan,

[0018] - a rotary drive device configured to rotate the heating fan around a fan rotation axis, and

[0019] - an air circulation cooling device configured to generate a cooling airflow capable of flowing at least partially in contact with the rotating drive device, the air circulation cooling device comprising a fresh air inlet, a centrifugal fan and a hot air outlet, the centrifugal fan comprising: a casing defining a receiving volume and comprising at least one casing air inlet fluidly connected to the fresh air inlet and the receiving volume and a casing air outlet fluidly connected to the receiving volume and the hot air outlet, and an impeller disposed in the receiving volume and having an axis of rotation of the impeller, the impeller being provided with several curved blades and each blade having an intrados and an extrados, the intrados of each blade being convex and the extrados of each blade being concave.

[0020] Although such a configuration of the centrifugal fan, and in particular of the impeller blades, slightly degrades the cooling airflow rate within the housing of the electric cooking appliance, such a configuration makes it possible to significantly reduce the noise generated by the centrifugal fan, and therefore by the electric cooking appliance.

[0021] Thus, the electric cooking appliance according to the present invention ensures satisfactory cooling, in particular of the rotating drive device, while generating relatively low noise levels compared to cooking appliances of the prior art.

[0022] The electric cooking appliance may also have one or more of the following characteristics, which may be taken alone or in combination.

[0023] According to one embodiment of the invention, the intrados of each blade is curved and convex and the extrados of each blade is curved and concave.

[0024] According to one embodiment of the invention, the intrados of each blade is defined by a first portion of a surface of revolution which is curved and convex, and the extrados of each blade is defined by a second portion of a surface of revolution which is curved and concave.

[0025] According to one embodiment of the invention, each blade is rounded and has a circular arc profile having a diameter of curvature between 30 mm and 45 mm, and for example about 38 mm.

[0026] According to one embodiment of the invention, the paddle wheel has an external diameter between 100 mm and 120 mm, for example between 105 mm and 115 mm, and advantageously about 107 mm.

[0027] According to one embodiment of the invention, the crankcase air inlet has an inlet diameter between 90 mm and 100 mm, and advantageously about 94 mm.

[0028] According to one embodiment of the invention, the crankcase air inlet opens into an upper wall of the crankcase.

[0029] According to one embodiment of the invention, the impeller is arranged eccentrically in the receiving volume so as to drive an airflow into a determined volume of the receiving volume which grows continuously until the crankcase air outlet.

[0030] According to one embodiment of the invention, the centrifugal fan is configured such that the gap between the outer peripheral surface of the impeller and the peripheral casing wall increases, for example, progressively, along the peripheral casing wall from its initial end to its final end. This configuration of the centrifugal fan promotes the flow of cooling air within the fan and further reduces the noise generated by the centrifugal fan.

[0031] According to one embodiment of the invention, the casing comprises a peripheral casing wall defining in part the receiving volume and extending around the impeller, and a first outlet side wall and a second outlet side wall which define in part the casing air outlet, the first outlet side wall extending from an initial end of the peripheral casing wall and the second outlet side wall extending from a final end of the peripheral casing wall.

[0032] According to one embodiment of the invention, the peripheral wall of the casing has overall a spiral arc shape extending around the axis of rotation of the wheel.

[0033] According to one embodiment of the invention, the spacing distance measured at the initial end of the peripheral wall of the housing has a first spacing value and the spacing distance measured at the final end of the peripheral wall of the housing has a second spacing value, a ratio of the second spacing value to the first spacing value is between 4 and 5, and is for example about 4.3.

[0034] According to one embodiment of the invention, a subtraction of the first spacing value from the second spacing value is between 17 mm and 23 mm, and for example about 20 mm.

[0035] According to one embodiment of the invention, the first spacing value is between 5 mm and 10 mm, and is for example about 6 mm.

[0036] According to one embodiment of the invention, the second spacing value is between 20 mm and 30 mm, and is for example about 26 mm.

[0037] According to one embodiment of the invention, the centrifugal fan is configured such that a straight line connecting the initial end of the peripheral housing wall to a free end of the first outlet side wall is inclined with respect to a tangent to the peripheral housing wall passing through the initial end of the peripheral housing wall at an angle of inclination greater than 105°, for example between 105° and 120°, and advantageously about 110°. Such a configuration of the centrifugal fan, and in particular of the housing air outlet, reduces the turbulence generated at the housing air outlet, and thus further reduces the noise generated by the centrifugal fan.

[0038] According to one embodiment of the invention, a final separation distance between the wheel rotation axis and the final end of the peripheral housing wall is between 70 mm and 90 mm, advantageously between 75 mm and 85 mm, and is for example about 79.5 mm.

[0039] According to one embodiment of the invention, an initial separation distance between the wheel rotation axis and the initial end of the peripheral housing wall is between 50 mm and 70 mm, advantageously between 55 mm and 65 mm, and is for example about 59.5 mm.

[0040] According to one embodiment of the invention, the ratio of the crankcase air outlet width to the second spacing value is between 2 and 3, advantageously between 2 and 2.5, and is, for example, approximately 2.15. Such a configuration of the centrifugal fan reduces the speed of the cooling airflow at the crankcase air outlet (while maintaining an equivalent flow rate due to the generated Venturi effect), and thus reduces turbulence at the crankcase air outlet. This also results in a further reduction of the noise generated by the centrifugal fan.

[0041] According to one embodiment of the invention, the crankcase air outlet has a width between 50 mm and 60 mm, and for example about 56 mm.

[0042] According to one embodiment of the invention, each blade has a proximal edge (the edge of the blade which is located on the side of the wheel rotation axis, i.e. the edge of the blade which is closest to said wheel rotation axis) which is inclined with respect to the wheel rotation axis and which extends towards the wall of the casing where the casing air inlet is located while moving away from said wheel rotation axis.

[0043] In one embodiment, at least a portion of the proximal edge of each blade has an orthogonal projection onto a closed surface formed by the crankcase air inlet. This arrangement improves air intake through the crankcase air inlet.

[0044] According to one embodiment of the invention, the maximum distance between the wheel rotation axis and the proximal edge of each blade is between 80 mm and 90 mm, and is for example about 84 mm.

[0045] According to one embodiment of the invention, the minimum distance between the wheel rotation axis and the proximal edge of each blade is between 70 mm and 80 mm, and is for example about 73 mm.

[0046] According to one embodiment of the invention, the center of the arc profile of each blade is offset from the wheel rotation axis by a distance substantially equal to the maximum distance between the wheel rotation axis and the proximal edge of said blade.

[0047] According to one embodiment of the invention, for each blade, a first plane containing the wheel rotation axis and passing through the point on the proximal edge of said blade furthest from the wheel rotation axis and a second plane containing the wheel rotation axis and passing through the center of the arc profile of said blade are inclined to each other at an internal angle between 25° and 35°, and for example about 27°.

[0048] According to one embodiment of the invention, for each blade, a third plane containing the wheel's axis of rotation and passing through the distal edge (the edge of the blade located opposite the wheel's axis of rotation, i.e., the edge of the blade furthest from said wheel's axis of rotation) of said blade is inclined relative to the respective second plane at an external angle less than the respective internal angle. Such a configuration of the centrifugal fan makes it possible to generate an optimal compression effect / generated noise ratio within the casing.

[0049] According to one embodiment of the invention, the centrifugal fan is configured such that the crankcase air outlet is substantially centered with respect to a reference plane containing the impeller's axis of rotation. In other words, the centrifugal fan is configured such that a median vertical plane of the crankcase air outlet (i.e., dividing the crankcase air outlet into substantially identical left and right parts) is substantially intersecting (i.e., substantially containing) the impeller's axis of rotation.

[0050] According to one embodiment of the invention, the first exit side wall and the second exit side wall extend substantially parallel to each other.

[0051] According to one embodiment of the invention, the centrifugal fan is rotationally coupled to the rotary drive device. This arrangement allows the impeller and the heating fan to be rotated via the same rotary drive device, thereby reducing the manufacturing costs of the electric cooking appliance according to the present invention.

[0052] According to one embodiment of the invention, the heating fan has six blades. This configuration of the heating fan also reduces the noise generated by the electric cooking appliance according to the present invention.

[0053] According to one embodiment of the invention, the heating fan has a diameter between 120 mm and 140 mm, and for example about 132 mm.

[0054] According to one embodiment of the invention, the heating fan has a height between 15 mm and 17 mm.

[0055] According to one embodiment of the invention, the air circulation cooling device is configured such that the cooling airflow, generated by the air circulation cooling device, is able to flow in contact with at least one wall of the cooking container (for example a front face of the cooking container) and / or of the housing (for example a rear wall of the housing) which delimits at least part of an external surface of the electric cooking appliance.

[0056] According to one embodiment of the invention, the fan rotation axis is substantially coincident with the wheel rotation axis.

[0057] According to one embodiment of the invention, the rotational drive device comprises a drive motor and a drive shaft rotationally coupled to the drive motor, the drive shaft being rotationally fixed to the heating fan and the impeller.

[0058] According to one embodiment of the invention, the electric cooking appliance includes an exhaust duct configured to vent, to the outside of the electric cooking appliance, cooking fumes generated in the cooking container and the cooling airflow generated by the air circulation cooling device.

[0059] According to one embodiment of the invention, the exhaust duct is configured to be oriented upwards when the electric cooking appliance is in use and rests on a horizontal surface.

[0060] According to one embodiment of the invention, the exhaust duct opens into an upper part of the electric cooking appliance, and for example into an upper part of the casing.

[0061] According to one embodiment of the invention, the electric cooking appliance includes a filtration device, for example a cotton fiber filter or an activated carbon filter, configured to filter the cooking fumes generated in the cooking chamber before said fumes are expelled from the electric cooking appliance via the exhaust duct. Such a filtration device filters the cooking fumes but requires an increased airflow, resulting in increased noise. A compromise between the filtration of cooking fumes and the noise of the electric cooking appliance is therefore necessary, without, however, generating more noise, for equivalent filtration, than prior art cooling devices also equipped with a filtration device.

[0062] In this document, "cooking fumes" refers to any type of smoke generated during the cooking of food in the cooking vessel. Cooking fumes can have a wide variety of compositions depending on factors such as the type of food being cooked and the cooking temperatures. For example, cooking fumes may be heavily laden with water vapor, heavily laden with oil droplets, or contain a mixture of water vapor, oil droplets, and other odorous particles.

[0063] According to one embodiment of the invention, the filtration device is disposed in the exhaust duct.

[0064] According to one embodiment of the invention, the filtration device is configured to trap odors carried by cooking fumes and / or to at least partially purify the cooking fumes. In other words, the filtration device is an odor filtration device and / or a cooking fume purification device.

[0065] According to one embodiment of the invention, the electric cooking appliance includes an electronic control unit configured to control the operation of the electric cooking appliance according to at least one hot air cooking mode.

[0066] According to one embodiment of the invention, the electric cooking appliance includes a speed sensor configured to measure the rotational speed of the drive motor (and therefore of the impeller), the electronic control unit being configured to regulate the rotational speed of the drive motor to a predetermined speed. Such regulation of the drive motor's rotational speed prevents, in the event of significant changes in operating conditions (particularly temperature) within the receiving volume, a substantial variation in the rotational speed of the heating fan and the impeller, which would increase the noise of the electric cooking appliance.

[0067] According to one embodiment of the invention, the fresh air inlet is located on the housing, for example in a lower part of the housing. The fresh air inlet may, for example, open into a lower face of the housing.

[0068] According to one embodiment of the invention, the air circulation cooling device includes an air supply circuit configured to fluidly connect the crankcase air inlet to the fresh air inlet.

[0069] According to one embodiment of the invention, the centrifugal fan is arranged between the heating fan and the drive motor.

[0070] According to one embodiment of the invention, the centrifugal fan is disposed in the housing, and for example in an upper part of the housing.

[0071] According to one embodiment of the invention, the rotation drive device is disposed in the housing, and for example in an upper part of the housing.

[0072] According to one embodiment of the invention, the heating fan is configured to be located opposite a bottom wall of the cooking container.

[0073] According to one embodiment of the invention, the heating fan and the heating device are configured to be arranged in a cooking chamber delimited by the cooking container and the housing.

[0074] According to one embodiment of the invention, the cooking container is configured to occupy a cooking position in which the cooking container is disposed at least partially in the receiving housing and in which food contained in the cooking container is suitable for being cooked by the electric cooking appliance, and an access position in which the cooking container is at least partially removed from the receiving housing and in which food is suitable for being introduced into or removed from the cooking container.

[0075] According to one embodiment of the invention, the cooking container is a cooking drawer.

[0076] According to one embodiment of the invention, the cooking container comprises a cooking chamber configured to receive food to be cooked and to be accessible to a user when the cooking container is in the access position, the cooking chamber and the housing being configured to delimit a cooking chamber when the cooking container is in the cooking position.

[0077] According to one embodiment of the invention, the cooking container includes at least one gripping handle, for example attached to a front face of the cooking container.

[0078] According to one embodiment of the invention, the cooking vessel comprises an air circulation channel delimited at least in part by the front facade and a front face of the cooking vessel, the air circulation channel forming in part the air circulation cooling device (and more particularly in part the air supply circuit) and the cooling airflow generated by the air circulation cooling device being able to flow at least in part into said air circulation channel. Brief description of the figures

[0079] The present invention will be better understood with the aid of the following description with reference to the accompanying figures, in which identical reference signs correspond to structurally and / or functionally identical or similar elements.

[0080] This is a longitudinal cross-sectional view of an electric cooking appliance according to the present invention;

[0081] This is a perspective view of a centrifugal fan belonging to the electric cooking appliance of the;

[0082] This is a top view of the centrifugal fan of the;

[0083] This is a vertical cross-sectional view of the centrifugal fan of the;

[0084] This is a partial view from below of the centrifugal fan of the;

[0085] This is a perspective view of a paddle wheel belonging to the centrifugal fan of the;

[0086] This is a top view of the paddle wheel;

[0087] This is a vertical cross-sectional view of the waterwheel;

[0088] This is a perspective view from below of a heating fan belonging to the electric cooking appliance. Detailed description

[0089] In this document, the terms "lower", "upper", "front" and "rear" used to describe the electric cooking appliance refer to the electric cooking appliance in use, i.e. resting on a horizontal surface.

[0090] Unless otherwise stipulated, the term "substantially" means, in this document, "exactly or to within 10% or to within 10°".

[0091] Figures 1 to 9 depict an electric cooking appliance 1, and in particular a hot air cooking appliance, configured for cooking food such as meat, fish, vegetables, or other food products. The electric cooking appliance 1 includes, in particular, an electronic control unit 2 configured to control the operation of the electric cooking appliance 1 according to at least one hot air cooking mode. The cooking appliance 1 could, for example, be an air fryer.

[0092] According to the embodiment shown in the figures, the electric cooking appliance 1 comprises a housing 3 including a receiving compartment 4 provided in a lower part of the housing 3, and a cooking container 5, such as a cooking drawer, configured to receive food to be cooked and to be received in a removable manner in the receiving compartment 4.

[0093] More specifically, the cooking container 5 is configured to occupy a cooking position in which the cooking container 5 is disposed at least partially in the receiving housing 4 and in which food contained in the cooking container 5 is suitable for being cooked by the electric cooking appliance 1, and an access position, also called the loading position, in which the cooking container 5 is at least partially removed from the receiving housing 4 and in which food is suitable for being introduced into or removed from the cooking container 5.

[0094] According to the embodiment shown in the figures, the cooking vessel 5 includes a cooking chamber 6 configured to receive the food to be cooked and to be accessible to a user when the cooking vessel 5 is in the access position. The cooking chamber 6 and the housing 3 are configured to define a cooking chamber 7 when the cooking vessel 5 is in the cooking position.

[0095] The cooking vessel 5 further comprises a front face 8 configured to extend substantially in relation to a front portion of the cooking vessel 6, and at least one gripping handle 9 configured to be grasped by a user, so as to allow easy handling of the cooking vessel 5 by a user. Advantageously, the gripping handle 9 is integral with the front face 8.

[0096] According to the embodiment shown in the figures, the cooking container 5 further comprises a first transparent wall 11 mounted on a front face of the cooking tank 6 and a second transparent wall 12 mounted on the front face 8 and extending at least partially opposite the first transparent wall 11. Such a configuration of the cooking container 5 allows in particular a user to monitor the cooking of the food present in the cooking tank 6.

[0097] The electric cooking appliance 1 further includes a hot air cooking device 13 configured to generate a flow of hot air over the food received in the cooking container 5. The hot air cooking device 13 includes, in particular, a heating fan 14 configured to generate an air flow in the cooking chamber 7 and a heating device 15 associated with the heating fan 14 and configured to heat the air flow generated by the heating fan 14. Advantageously, the heating device 15 includes a resistive heating element and is configured to be located opposite a bottom wall of the cooking chamber 6.

[0098] According to the embodiment shown in the figures, the heating fan 14 has six blades (see the), and has a diameter between 120 mm and 140 mm, and advantageously about 132 mm, and a height between 15 mm and 17 mm.

[0099] The electric cooking appliance 1 further comprises a rotary drive device 16 configured to rotate the heating fan 14 around a fan rotation axis. The rotary drive device 16 is more specifically provided with a drive motor 17 and a drive shaft 18 rotationally coupled to the drive motor 17, the drive shaft 18 being rotationally fixed to the heating fan 14. Advantageously, the fan rotation axis is substantially vertical when the electric cooking appliance 1 rests on a horizontal surface. The motor is a single-phase asynchronous motor, specifically a shaded-pole type. The motor rotates counterclockwise when viewed from above the cooking appliance.

[0100] According to the embodiment shown in the figures, the rotating drive device 16 is arranged in an upper compartment 19 delimited by the housing 3, and the heating fan 14 and the heating device 15 are configured to be arranged in the cooking chamber 7.

[0101] The electric cooking appliance 1 also includes an air circulation cooling device configured to generate a cooling airflow capable of flowing at least partly in contact with the rotating drive device 16, and more particularly in contact with the drive motor 17, so as to allow the latter to be cooled.

[0102] The air circulation cooling device includes more particularly a centrifugal fan 21 disposed in the housing 3, and more particularly in the upper compartment 19, and coupled in rotation to the rotating drive device 16. Advantageously, the centrifugal fan 21 is disposed between the heating fan 14 and the drive motor 17.

[0103] As shown in particular in figures 2 and 5, the centrifugal fan 21 includes in particular a casing 22, also called a volute, defining a receiving volume 23 and comprising a casing air inlet 24 fluidically connected to the receiving volume 23 and a casing air outlet 25 fluidly connected to the receiving volume 23.

[0104] Advantageously, the crankcase air inlet 24 is generally circular and opens into an upper wall of the crankcase 22. The crankcase air inlet 24 may, for example, have an inlet diameter of between 90 mm and 100 mm, and advantageously of about 94 mm, and the crankcase air outlet 25 may, for example, have a width of between 50 mm and 60 mm, and advantageously of about 56 mm.

[0105] The centrifugal fan 21 further comprises an impeller 26 having an impeller axis of rotation A and which is arranged eccentrically within the receiving volume 23. Advantageously, the impeller axis of rotation A coincides with the fan's axis of rotation. The impeller 26 may have an external diameter between 100 mm and 120 mm, advantageously between 105 mm and 115 mm, and for example, approximately 107 mm.

[0106] According to the embodiment shown in the figures, the centrifugal fan 21 is configured such that the crankcase air outlet 25 is substantially centered with respect to a reference plane containing the axis of rotation of wheel A. In other words, the centrifugal fan 21 is configured such that a median vertical plane of the crankcase air outlet 25 (i.e. dividing the crankcase air outlet 25 into a substantially identical left and right part) is secant (i.e. contains) the axis of rotation of wheel A.

[0107] As shown in particular on the, the paddle wheel 26 is provided with several paddles 27, and each paddle 27 has an intrados 27.1 (surface of the paddle 27 which is oriented towards the front with respect to the direction of rotation of the paddle wheel 26) and an extrados 27.2 (surface of the paddle 27 which is oriented towards the rear with respect to the direction of rotation of the paddle wheel 26).

[0108] The intrados 27.1 of each blade 27 is more particularly defined by a first portion of its surface of revolution which is curved and convex, and the extrados 27.2 of each blade 27 is more particularly defined by a second portion of its surface of revolution which is curved and concave. Advantageously, each blade 27 is rounded and has a circular arc profile with a diameter of curvature between 30 mm and 45 mm, and for example, approximately 38 mm.

[0109] According to the embodiment shown in the figures, each blade 27 has a proximal edge 27.3 (the edge of said blade 27 located on the side of the wheel rotation axis A, i.e., the edge of said blade 27 closest to the wheel rotation axis A) inclined with respect to the wheel rotation axis A and extending towards the housing wall 22 where the housing air inlet 24 is located, while moving away from the wheel rotation axis A. The maximum distance Dmax between the wheel rotation axis A and the proximal edge 27.3 of each blade 27 can, for example, be between 80 mm and 90 mm, and is advantageously about 84 mm, and the minimum distance Dmin between the wheel rotation axis A and the proximal edge 27.3 of each blade 27 can, for example, be between 70 mm and 80 mm, and is advantageously about 73 mm.Advantageously, the center C of the arc profile of each blade 27 is offset from the wheel rotation axis A by a distance substantially equal to the maximum distance Dmax.

[0110] According to the embodiment shown in the figures, the casing 22 comprises a peripheral casing wall 28 partially defining the receiving volume 23 and extending around the impeller 26, and a first outlet side wall 29 and a second outlet side wall 30 that partially define the casing air outlet 25. The first outlet side wall 29 extends more particularly from an initial end E1 of the peripheral casing wall 28, while the second outlet side wall 30 extends more particularly from an end E2 of the peripheral casing wall 28. According to the embodiment shown in the figures, the first outlet side wall 29 and the second outlet side wall 30 extend substantially parallel to each other.

[0111] An initial separation distance between the wheel rotation axis A and the initial end E1 of the peripheral wall of the housing 28 can be between 50 mm and 70 mm, advantageously between 55 and 65 mm, and is for example about 59.5 mm, and a final separation distance between the wheel rotation axis A and the final end E2 of the peripheral wall of the housing 28 can be between 70 mm and 90 mm, advantageously between 75 mm and 85 mm, and is for example about 79.5 mm.

[0112] According to the embodiment shown in the figures, the centrifugal fan 21 is configured such that a straight line connecting the initial end E1 of the peripheral wall of the housing 28 to a free end of the first outlet side wall 29 is inclined with respect to a tangent to the peripheral wall of the housing 28 passing through the initial end E1 of the peripheral wall of the housing 28 at an angle of inclination α which is greater than 105°, for example between 105° and 120°, and advantageously about 110°.

[0113] As shown more particularly in the figure, the peripheral wall of the casing 28 has overall a spiral arc shape extending around the axis of rotation of the wheel A, and the centrifugal fan 21 is configured such that a gap distance between the outer peripheral surface 26.1 of the impeller 26 and the peripheral wall of the casing 28 increases, for example gradually, along the peripheral wall of the casing 28 and from the initial end E1 of the peripheral wall of the casing 28 to the final end E2 of the peripheral wall of the casing 28.

[0114] According to one embodiment of the invention, the spacing distance measured at the initial end E1 of the peripheral wall of the housing 28 has a first spacing value, and the spacing distance measured at the final end E2 of the peripheral wall of the housing 28 has a second spacing value which is greater than the first value and which is defined such that a ratio of the second spacing value to the first spacing value is between 4 and 5, and is for example about 4.3.

[0115] According to one embodiment of the invention, the first gap value is between 5 mm and 10 mm, and is, for example, approximately 6 mm, and the second gap value is between 20 mm and 30 mm, and is, for example, approximately 26 mm. Advantageously, a subtraction of the first gap value from the second gap value is between 17 mm and 23 mm, and is, for example, approximately 20 mm, and a ratio of the width of the crankcase air outlet 25 to the second gap value is between 2 and 3, advantageously between 2 and 2.5, and is, for example, approximately 2.15.

[0116] As shown in the figure, for each blade 27, a first plane P1 containing the axis of rotation of wheel A and passing through the point on the proximal edge 27.3 of said blade 27 furthest from the axis of rotation of wheel A and a second plane P2 containing the axis of rotation of wheel A and passing through the center of the arc profile of said blade 27 are inclined to each other at an internal angle between 25° and 35°, and for example about 27°. Advantageously, for each blade 27, a third plane P3 containing the axis of rotation of wheel A and passing through the distal edge 27.4 (the edge of the blade 27 located opposite the axis of rotation of wheel A, i.e. the edge of the blade 27 which is furthest from said axis of rotation of wheel A) of said blade 27 is inclined with respect to the respective second plane P2 by an external angle less than the respective internal angle.

[0117] As shown more particularly in the figure, the air circulation cooling device also includes a fresh air inlet 31 located in a lower part of the housing 3, and for example opening into a lower face of the housing 3, an air supply circuit 32 configured to fluidly connect the crankcase air inlet 24 of the centrifugal fan 21 to the fresh air inlet 31, and a hot air outlet 33 located in an upper part of the housing 3 and fluidly connected to the crankcase air outlet 25.

[0118] The air supply circuit 32 may, for example, include a first circuit section (schematically represented by arrow F1 in the diagram) formed partly by an air circulation duct 34 provided on the cooking vessel 5 and partly delimited by the first transparent wall 11 and the second transparent wall 12. The air circulation duct 34 is more specifically configured to allow the circulation of a portion of the cooling airflow, generated by the air circulation cooling device, between the first transparent wall 11 and the second transparent wall 12. Such a first circuit section makes it possible, in particular, to cool the second transparent wall 12 provided on the front panel 8, and thus to limit the risk of burns to a user when handling the cooking vessel 5.

[0119] The air supply circuit 32 may also include a second circuit portion (schematically represented by arrow F2 on the diagram) delimited in part by a rear wall of the housing 3.

[0120] According to the embodiment shown in the figures, the electric cooking appliance 1 further includes an exhaust duct 35 configured to vent cooking fumes generated in the cooking container 5 and also the cooling airflow generated by the circulating cooling device to the outside of the electric cooking appliance 1. Advantageously, the exhaust duct 35 includes the aforementioned hot air outlet 33, terminates in an upper part of the electric cooking appliance 1, and for example in an upper part of the housing 3, and is configured to be oriented upwards when the electric cooking appliance 1 is in use and resting on a horizontal surface. Such a configuration of the exhaust duct 35 further reduces the noise generated by the electric cooking appliance 1, since the exhaust duct 35 acts as a silencer.Furthermore, such a configuration of the exhaust duct 35 avoids excessive heating of a wall or partition located opposite the rear wall of the housing 3.

[0121] According to one embodiment of the invention, the electric cooking appliance 1 could further comprise a filtration device (not shown in the figures), for example disposed in the exhaust duct 35, configured to filter, in particular, the cooking fumes generated in the cooking chamber 7, before said cooking fumes are exhausted outside the electric cooking appliance 1 via the exhaust duct 35. Such a filtration device makes it possible to filter the cooking fumes, but will require an increase in the air flow rate, resulting in an increase in the noise of the electric cooking appliance 1. A compromise between the filtration of cooking fumes and the noise of the electric cooking appliance 1 is therefore necessary, without, however, generating more noise for the same level of filtration than cooling devices in the prior art that are also equipped with a filtration device.The filtration device can, for example, be configured to trap odors carried by cooking fumes and / or to at least partially purify cooking fumes, i.e. to trap.

[0122] According to one embodiment of the invention, the electric cooking appliance 1 could also include a speed sensor, in particular of the Hall effect type (visible in the figure), comprising a magnet and a ring fixed to the shaft of the drive motor 17, and configured to measure the rotational speed of the drive motor 17 (and therefore of the impeller 26). The electronic control unit 2 could be configured to regulate the rotational speed of the drive motor 17 to a predetermined speed. Such regulation of the rotational speed of the drive motor 17 makes it possible to avoid, in the event of significant changes in operating conditions (in particular temperature) within the receiving volume 23, a significant variation in the rotational speed of the impeller 26, which would then be likely to increase the noise generated by the centrifugal fan 21.

[0123] According to another embodiment of the invention not shown in the figures, the electric cooking appliance 1 could be of the oven type and could then include a movable door between a first door position in which the door prevents access to the cooking container 5, and a second door position in which the door allows access to the cooking container 5.

[0124] According to yet another embodiment of the invention, not shown in the figures, the electric cooking appliance 1 could include a movable lid, for example, mounted pivotally, between a closed position in which the lid prevents access to the cooking container 5, and an open position in which the lid allows access to the cooking container. According to such an embodiment of the invention, the heating device 15 may, for example, be fixed to the lid, the heating fan 14 may, for example, be mounted for rotation on the lid, and the rotating drive device 16 may, for example, be disposed in an internal compartment defined by the lid.

[0125] Of course, the present invention is in no way limited to the embodiments described above, which have been given only by way of example. Modifications remain possible, particularly with regard to the composition of the various elements or by substitution of technical equivalents, without departing from the scope of protection of the invention.

Claims

Electric cooking appliance (1) comprising: - a housing (3) including a receiving compartment (4), - a cooking container (5) disposed in the receiving compartment (4) and configured to receive food to be cooked, - a hot air cooking device (13) configured to generate a flow of hot air over the food received in the cooking container (5), the hot air cooking device (13) including a heating fan (14) configured to generate an airflow and a heating device (15) configured to heat the airflow generated by the heating fan (14), - a rotating drive device (16) configured to rotate the heating fan (14) around a fan rotation axis, and - an air circulation cooling device configured to generate a cooling airflow capable of flowing at least partially in contact with the rotating drive device (16),The air circulation cooling device comprises a fresh air inlet (31), a centrifugal fan (21), and a hot air outlet (33). The centrifugal fan (21) comprises: a housing (22) defining a receiving volume (23) and including at least one housing air inlet (24) fluidly connected to the fresh air inlet (31) and the receiving volume (23), and a housing air outlet (25) fluidly connected to the receiving volume (23) and the hot air outlet (33); and an impeller (26) disposed in the receiving volume (23) and having an impeller axis of rotation (A). The impeller (26) is provided with several curved blades (27), each blade (27) having an intrados (27.1) and an extrados (27.2), characterized in that the intrados (27.1) of each blade (27) is convex and the extrados (27.2) of each blade (27) is concave. Electric cooking appliance (1) according to claim 1, in which the paddle wheel (26) is arranged eccentrically in the receiving volume (23). Electric cooking apparatus (1) according to claim 1 or 2, wherein the intrados (27.1) of each blade (27) is defined by a first portion of a surface of revolution which is curved and convex, and the extrados (27.2) of each blade (27) is defined by a second portion of a surface of revolution which is curved and concave. Electric cooking appliance (1) according to any one of claims 1 to 3, wherein each blade (27) is rounded and has a circular arc profile having a diameter of curvature between 30 mm and 45 mm. Electric cooking appliance (1) according to any one of claims 1 to 4, in which each blade (27) has a proximal edge (27.3) which is inclined with respect to the wheel rotation axis (A) and which extends in the direction of the housing wall (22) where the housing air inlet (24) is located while moving away from said wheel rotation axis (A). Electric cooking appliance (1) according to any one of claims 1 to 5, in which the casing (22) comprises a peripheral casing wall (28) partially defining the receiving volume (23) and extending around the impeller (26), and a first outlet side wall (29) and a second outlet side wall (30) partially defining the casing air outlet (25), the first outlet side wall (29) extending from an initial end (E1) of the peripheral casing wall (28) and the second outlet side wall (30) extending from an end (E2) of the peripheral casing wall (28). Electric cooking appliance (1) according to claim 6, wherein the centrifugal fan (21) is configured such that a gap distance between the outer peripheral surface (26.1) of the impeller (26) and the peripheral wall of the housing (28) increases along the peripheral wall of the housing (28) and from the initial end (E1) of the peripheral wall of the housing (28) to the final end (E2) of the peripheral wall of the housing (28). Electric cooking appliance (1) according to claim 7, wherein the gap distance measured at the initial end (E1) of the peripheral wall of the housing (28) has a first gap value and the gap distance measured at the final end (E2) of the peripheral wall of the housing (28) has a second gap value, a ratio of the second gap value to the first gap value is between 4 and 5. Electric cooking appliance (1) according to any one of claims 6 to 8, wherein the centrifugal fan (21) is configured such that a straight line connecting the initial end (E1) of the peripheral housing wall (28) to a free end of the first outlet side wall (29) is inclined with respect to a tangent to the peripheral housing wall (28) passing through the initial end (E1) of the peripheral housing wall (28) at an angle of inclination (α) which is greater than 105°. Electric cooking appliance (1) according to any one of claims 6 to 9, wherein a final separation distance between the wheel rotation axis (A) and the final end (E2) of the peripheral wall of the housing (28) is between 70 mm and 90 mm. Electric cooking appliance (1) according to any one of claims 6 to 10, wherein an initial separation distance between the wheel rotation axis (A) and the initial end (E1) of the peripheral wall of the housing (28) is between 50 mm and 70 mm. Electric cooking appliance (1) according to any one of claims 1 to 11, wherein the centrifugal fan (21) is configured such that the air outlet of the casing (25) is substantially centered with respect to a reference plane containing the axis of rotation of the wheel (A). Electric cooking appliance (1) according to any one of claims 1 to 12, wherein the centrifugal fan (21) is rotationally coupled to the rotating drive device (16). Electric cooking appliance (1) according to any one of claims 1 to 13, wherein the heating fan (14) has six blades. Electric cooking appliance (1) according to any one of claims 1 to 14, wherein the air circulation cooling device is configured such that the cooling airflow, generated by the air circulation cooling device, is able to flow in contact with at least one wall of the cooking container (5) and / or of the housing (3) which delimits at least part of an external surface of the electric cooking appliance (1). Electric cooking appliance (1) according to any one of claims 1 to 15, which includes an exhaust duct (35) configured to vent, to the outside of the electric cooking appliance (1), cooking fumes generated in the cooking container (5) and the cooling airflow generated by the air circulation cooling device. Electric cooking appliance (1) according to claim 16, wherein the exhaust duct (35) is configured to be oriented upwards when the electric cooking appliance (1) is in use and resting on a horizontal surface.

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