DE202017102536U1 - Device for preparing food - Google Patents

Abstract

Apparatus (10, 110, 210) for preparing food, in particular by means of hot air, comprising: - a housing (12, 112, 212), - a treatment chamber (24, 124, 224) housed in the housing (12, 112, 212), - a heating unit (46, 246) for heating a treatment fluid, which in operation flows through the treatment chamber (24, 124, 224), - a ventilation unit (48, 248) with a drive (54, 254) and a ventilation wheel (60, 260) coupled together by a shaft (58, 258), the ventilation wheel (60, 260) being disposed in a first region (78, 278) through which the treatment fluid flows Drive (54, 254) in a second region (80, 280) which is separated by a partition (34, 234) from the first region (78, 278), wherein the shaft (58, 258) has an opening (300 ) in the partition wall (34, 234), and wherein at the opening (300) a labyrinth seal (304) is formed, which is between n the shaft (58, 258) and the partition wall (34, 234) extends.

Description

AREA OF REVELATION

The present disclosure relates to a device for preparing food, in particular by means of hot air, which has a housing, a treatment chamber, a heating unit and a ventilation unit, wherein the heating unit serves to heat a treatment fluid which flows through the treatment chamber during operation of the device, and wherein the ventilation unit comprises a ventilation wheel which generates a defined flow of the treatment fluid in the treatment chamber.

In particular, the present disclosure relates to so-called hot air fryers, also referred to as dry fryer. Another common trade name of such devices is Airfryer. However, reference to hot air fryers is not meant to be limiting.

BACKGROUND OF THE REVELATION

From the WO 2012/168897 A1 a device for preparing food is known, comprising: a housing, a food preparation chamber in the housing with an inner wall forming a food receiving space with an air inlet slot and an air outlet slot, a fan for directing a flow of hot air successively through the air inlet slot, the food receiving space and the air discharge slot, and an air passage for returning the flow of air from the air outlet slot toward the air inlet slot separately from the food receiving space, the housing comprising a cooling air passage and a hot air supply for discharging the flow of hot air from the food preparation chamber out of the housing a constricted portion having a reduced cross-sectional area, so that a Venturi effect arises in the hot air supply, wherein an outlet in the cooling air passage with the hot air supply at the constricted portion tt, so that a low pressure region is formed at the outlet and a stream of cooling air is drawn through the cooling air passage and into the hot air supply.

Recently, hot air fryers and similar food preparation equipment have become widely used. The preparation of food by flowing around hot air differs significantly from established preparation methods, such as conventional frying. The classic frying takes place in a fryer, which can also be referred to as an electric frying fat heater. When frying, foods are fried in hot fat or oil. This type of preparation often leads to an increased oil content or fat content of the prepared foods. Hot air fryers respond to the desire to prepare food products that have a reduced fat content on the one hand and tasty on the other hand and can be prepared, if possible, with a process that is at least similar to classic frying. In particular, Heißluftfritteusen are at least partially suitable as a substitution for traditional fryers.

The principle of Heißluftfritteusen and similar devices for the preparation of food based on the flow around the food with a heated or heated fluid, in particular with air. It is understood that the air used to heat-treat the food may be oily, fatty and / or hydrous. This may be due, for example, to constituents of the food being heated in the treatment chamber. Also occasionally small amounts of oil, fat or other additives can be added. As such, the distinction between traditional deep fryers and other appliances which fry foods in hot oil or fat is not to be understood as meaning that the heat treatment of devices in the sense of the present disclosure is fat free. However, a significant reduction of fat in the prepared foods can be achieved. For example, this can include a reduction in fat content of up to 80% for French fries.

Devices according to the present disclosure are suitable for various types of preparation. This may include frying, grilling, frying or even baking. There may be different accessories for the various types of preparation.

When operating Heißluftfritteusen and similar devices for preparing food by means of hot air must be expected depending on the type of food with a certain loss of moisture, which is reflected in an increased humidity of the treatment air or the treatment fluid. Increased moisture as well as other components of the treatment fluid, such as oil, steam and other fumes of food to be treated can be fundamentally problematic for electrical components, electronic components and / or operator interfaces of the device, as long as the treatment fluid reaches sensitive components and components.

A common embodiment of Heißluftfritteusen includes, for example, a housing with an extract that carries an insert in which received the food to be treated become. At least the insert can usually be removed, for example for cleaning purposes. The insert is accommodated in the treatment chamber of the device in such a way that the largest possible flow around the foodstuff received in the application is made possible with the treatment fluid. To generate the fluid flow, a ventilation unit is provided, which often comprises a ventilation wheel, which is arranged above the insert. An axis of rotation of the ventilation wheel is usually oriented vertically. Above the ventilation wheel, a drive is provided for the ventilation unit, which usually comprises an electric motor. The drive is accordingly often arranged at the upper end of a housing of the device. The ventilation wheel itself is exposed directly to the treatment fluid and accordingly exposed to elevated temperatures and, depending on the application, increased humidity. Furthermore, the ventilation wheel comes into contact with vapor, fatty and oily components and with other constituents of the treatment fluid.

The drive for the ventilation unit is isolated as far as possible from the treatment chamber, for example in order to avoid an excessive increase in the temperature of the drive motor. However, due to the mechanical coupling between the drive motor and the ventilation wheel, it can not always be ruled out that the treatment fluid will be in a range that does not actually belong to the treatment chamber. This can lead to long-term damage and malfunction.

Another constraint is to arrange the ventilation wheel as close as possible to the food to be treated, that is, for example, during use, which carries the food. In this way, flow losses and the like can be minimized. It should also be noted that the ventilation unit is coupled to a heating unit that heats or heats the treatment fluid, which ultimately effects the heat treatment of the food.

There are therefore types of Heißluftfritteusen established in which the ventilation of the ventilation unit is cantilevered. In other words, no bearing is regularly provided on the side of the ventilation wheel which faces the treatment chamber. This simplifies the flow guidance, since no frame-side or housing-side receptacle for a bearing is provided on the corresponding end face of the ventilation wheel.

However, the floating mounting of the ventilation wheel requires an increased clearance, which must be taken into account in the separation of the treatment area and the area in which approximately the motor of the drive for the ventilation unit is provided.

Consequently, there is room for improvement in hot air fryers and similar food preparation equipment.

SUMMARY OF THE REVELATION

Against this background, the disclosure is based on the object of specifying a device for heat treatment of foods, in particular by means of hot air, which can be reliably operated and has a long service life. In particular, the device should be made as robust as possible, so that electrical and / or electronic components are not exposed to excessive loads by the treatment fluid. Preferably, the design of the device allows the use of low cost electrical and electronic components. Furthermore, the device preferably has a defined and well-insulated separation between the treatment chamber and other areas.

• - ein Gehäuse,
• - eine Behandlungskammer, die im Gehäuse ausgebildet ist,
• - eine Heizeinheit zur Erwärmung eines Behandlungsfluides, das im Betrieb die Behandlungskammer durchströmt,
• - eine Ventilationseinheit mit einem Antrieb und einem Ventilationsrad, die über eine Welle miteinander gekoppelt sind,

wobei das Ventilationsrad in einem ersten Bereich angeordnet ist, der vom Behandlungsfluid durchströmt wird,
wobei der Antrieb in einem zweiten Bereich angeordnet ist, der durch eine Trennwand vom ersten Bereich abgetrennt ist,
wobei die Welle eine Öffnung in der Trennwand durchragt, und
wobei bei der Öffnung eine Labyrinthdichtung ausgebildet ist, die sich zwischen der Welle und der Trennwand erstreckt.According to a first aspect of the present disclosure, a device for preparing foodstuffs, in particular by means of hot air, is disclosed, which has the following:

• a housing,
• a treatment chamber formed in the housing,
• a heating unit for heating a treatment fluid which flows through the treatment chamber during operation,
• a ventilation unit with a drive and a ventilation wheel, which are coupled to one another via a shaft,

wherein the ventilation wheel is arranged in a first region, through which the treatment fluid flows,
wherein the drive is arranged in a second region which is separated from the first region by a dividing wall,
wherein the shaft extends through an opening in the partition wall, and
wherein at the opening a labyrinth seal is formed, which extends between the shaft and the partition wall.

This aspect is based on the recognition that the labyrinth seal can increase the flow resistance for the treatment fluid in such a way that the risk of a transfer of the treatment fluid into the area in which the drive unit of the ventilation unit is arranged is significantly minimized. Accordingly, the danger of contact the treatment fluid with electrical and electronic components as well as operator interfaces significantly reduced. Overall, this leads to an increased service life and to a reduced component load on the side which is separated from the treatment chamber by the dividing wall.

For the purposes of the present disclosure, the first region is the region where the food and components of the device are deliberately exposed to the heated fluid stream. In other words, the first region may also be referred to as a hot air side. For the purposes of the present disclosure, the second area is a surrounding area that is deliberately separated from the treatment area. In the surrounding area, no entry of the treatment fluid is desired. In the surrounding area, electrical and / or electronic components of the device are arranged. This may also relate to a control device. Furthermore, the motor for the ventilation unit is arranged in the second area. In other words, the second area may also be referred to as the cooling air side.

The terms hot air side and cooling air side are not to be understood as limiting so that there is a perfect insulation between the two areas. Instead, a certain gradient ("gray area") should always be expected between the first area and the second area. However, in the context of the present disclosure measures are proposed to isolate the second area even better from the first area.

The labyrinth seal can also be commonly referred to as a gap seal. A labyrinth seal is preferably a non-contact shaft seal. The effect of a labyrinth seal is based in particular on the extension of the flow path through the design of the gap. As a result, the flow resistance is substantially increased, so that the risk of a transfer of the treatment fluid is significantly reduced. Labyrinth seals have the advantage that they can be carried out wear-free, if there is no contact between stationary and moving parts.

According to an exemplary embodiment of the device, the labyrinth seal defines a flow path between the first region and the second region, whose length is at least twice, preferably at least three times, more preferably at least five times an axial extent of the labyrinth seal. In this way, the flow path can be further extended without increasing the axial space requirement. With increasing length of the flow path, the flow resistance increases. This increases the sealing effect.

According to a further exemplary embodiment of the device, the labyrinth seal has a flow channel with a circumferential cross section with at least one directional deflection, preferably with at least two directional deflections.

The flow channel may be designed as a rotational body, wherein the cross section of the flow channel is rotated about a longitudinal axis of the shaft. Overall, the flow channel is tube-shaped. The directional deflection of the flow channel includes deflections / deflections of more than 30 °.

According to a development of this embodiment, the flow channel comprises a circumferential gap with preferably S-shaped or Z-shaped cross-section. In other words, the gap corresponds to a rotational body with an S-shaped or Z-shaped wall which is rotated about the longitudinal axis of the shaft. The directional deflections in an S-shaped or Z-shaped cross section are for example 2 x 180 ° or 4 x 90 °. In other words, at least part of the labyrinth seal forms a baffle plate, which ensures the deflection of the flow channel. In this way, the flow resistance can be further increased.

According to a further exemplary embodiment, the circumferential gap, which is formed by the flow channel, has a substantially constant thickness d, preferably along its S-shaped or Z-shaped extension. The gap has, for example, a thickness d of less than 2.0 mm, preferably less than 1.2 mm. The thickness d of the gap defines a radial play and an axial clearance of the labyrinth seal. This is particularly advantageous when the ventilation of the ventilation unit is mounted on the fly. Thus, it is also ensured in this embodiment that the labyrinth seal works without contact when the device is operated.

According to a further exemplary embodiment of the device, the labyrinth seal comprises at least one shaft-side section and a housing-side section which are rotatable relative to each other when the shaft is driven. The shaft-side portion and the housing-side portion define a boundary of the circumferential gap of the labyrinth seal.

According to a further exemplary embodiment of the device, the shaft-side section is relative to the housing-side section rotatable without contact. Thus, the labyrinth seal can be operated wear-free.

According to a further exemplary embodiment of the device, the dividing wall between the first region and the second region has a shielding plate which forms the opening. The shielding plate is preferably a deep-drawn shielding plate. The shield is recorded, for example, fixed to the housing. The shielding plate can also form at least a partial body of the labyrinth seal in addition to the partition and the opening formed in this. This is especially true when it is the shielding a deep-drawn shielding. It is understood that the partition can also consist of other materials that are at least sufficiently temperature resistant and food grade.

According to a further embodiment of the device, the labyrinth seal on a solid collar, which is designed as part of the partition and surrounds the opening. This is particularly advantageous if the partition is designed as a shielding. Accordingly, the fixed collar of the labyrinth seal can be designed as an integral part of the partition wall.

According to a further exemplary embodiment of the device, the fixed collar extends from the dividing wall in the direction of the first region, ie in the direction of the treatment chamber. On the one hand, the collar forms part of the labyrinth seal. In addition, the solid collar can also increase the strength of the partition. Overall, the stability of the partition and thus of the housing of the device increases.

According to a further exemplary embodiment, the labyrinth seal has a rotatable collar, which is rotatably connected to the shaft and extends in the direction of the second region. For the purposes of the present disclosure, the term rotatably connected to a connection between the rotatable collar and the shaft, which causes a rotational drive of the collar when the shaft is driven. In particular, the rotatable collar may be associated with a disc which is received on the shaft. The disk may be referred to in particular as a bell disk or cylinder disk. The disc has, at least in exemplary embodiments, a flat ring from which the collar extends. The collar is cylindrical, at least conical, designed.

According to a further exemplary embodiment of the device, the labyrinth seal has two interlocking circumferential cylinder walls, wherein a first cylinder wall of the partition and a second cylinder wall of the shaft is associated, wherein the second cylinder wall surrounds the first cylinder wall, and wherein the first cylinder wall surrounds the shaft. In general, the first cylinder wall and the second cylinder wall may be rotary bodies that include cylinders, conical bodies, and other rotating bodies having circumferential walls. The first cylinder wall can also be referred to as a fixed cylinder wall. The second cylinder wall can also be referred to as a rotatable cylinder wall. The first cylinder wall and the second cylinder wall engage with each other to define between them the gap, which provides for the increase of the flow resistance.

According to a further exemplary embodiment of the device, a fan wheel for cooling the drive is also provided in addition to the ventilation wheel. By way of example, the fan wheel is accommodated on the shaft in the second region and in particular is arranged between a motor of the drive and the dividing wall. In other words, the fan is taken on the cold air side. By contrast, the ventilation wheel is accommodated on the hot air side. Between the ventilation wheel and the fan wheel, the partition extends, in which the labyrinth seal is provided.

The task of the ventilation wheel is to generate a favorable fluid flow in the treatment chamber for the heat treatment of the food. The task of the fan wheel, however, is to dissipate warm air from the engine of the drive and to supply air to the engine with a lower temperature level.

According to a further exemplary embodiment of the device, the shaft is mounted in the second region, wherein in the first region for the shaft results in a flying bearing. In particular, the shaft extends through the opening in the partition wall without contact.

This design in combination with the labyrinth seal at the opening has the advantage that no additional components are required in the first area, which can affect the fluid flow for the heat treatment of the food on the one hand. Furthermore, this design increases the robustness, since the number of parts in the first area is minimized overall.

According to a further exemplary embodiment, the device is designed using the labyrinth seal as Heißluftfritteuse or Trockenfritteuse.

It is understood that the abovementioned and those still to be explained below Features of the disclosure can be used not only in the combination specified, but also in other combinations or alone, without departing from the scope of the disclosure.

list of figures

• 1 eine schematische Querschnittsansicht einer Vorrichtung zur Zubereitung von Nahrungsmitteln auf Basis einer Umströmung mit heißer Luft;
• 2 eine teilweise explodierte perspektivische Darstellung einer Vorrichtung zur Zubereitung von Nahrungsmitteln;
• 3 eine seitliche Schnittansicht einer weiteren Ausgestaltung einer Vorbereitung zur Zubereitung von Nahrungsmitteln;
• 4 eine Teilansicht einer Ventilationseinheit der Vorrichtung gemäß Anspruch 3 in vergrößerter Darstellung;
• 5 eine weiter vergrößerte Teilansicht der Darstellung gemäß 4; und
• 6 eine perspektivische explodierte Ansicht von Komponenten der in 4 veranschaulichten Ventilationseinheit.

These and other aspects of the disclosure will be illustrated and explained with reference to the embodiments described below. Show it:

• 1 a schematic cross-sectional view of an apparatus for preparing food based on a flow of hot air;
• 2 a partially exploded perspective view of a device for preparing food;
• 3 a side sectional view of another embodiment of a preparation for the preparation of food;
• 4 a partial view of a ventilation unit of the device according to claim 3 in an enlarged view;
• 5 a further enlarged partial view of the illustration according to 4 ; and
• 6 a perspective exploded view of components of the 4 illustrated ventilation unit.

DETAILED DESCRIPTION OF EXAMPLES

1 illustrates a schematic, highly simplified sectional view of an exemplary embodiment of a device for preparing food, which is generally designated 10. The device 10 may be referred to in particular as Heißluftfritteuse or Trockenfritteuse. An active principle of the preparation in the device 10 It is based on flowing around the food to be treated with hot air to perform a heat treatment. This is preferably done "dry", at least in comparison to conventional fryers that fry foods in a bath of fat or oil.

The device 10 has a housing 12 on. The housing 12 comprises a lower part 14, which may also be referred to as a base. Furthermore, an upper part 16 intended. In the case 12 is an excerpt 18 provided, which is laterally removable, at least laterally to open. To open and close the drawer 18 is a handle 20 intended. The extract 18 includes a shell 22 that defines a wall. The shell 22 is about pot-shaped or cup-shaped.

In the interior of the housing 12 is a treatment chamber 24 trained, in which the preparation, in particular the heat treatment, the food is carried out. For example, the extract shows 18 for this purpose an insert 26 on, which is designed in exemplary embodiments basket-like or sieve-like and includes a corresponding wall 28. The wall 28 is at least partially apertured or perforated to allow flow through the treatment chamber 24 to enable. The wall 28 defines an interior 30 which is available for heat treatment.

The principle of action of the preparation in the device 10 Based on the flow around the food with heated air, whereby a defined flow is generated. In this way, by the so-called Maillard reaction in addition to the actual heating or cooking of the food a tasty crust can be produced, for example in potato products (French fries), baked goods or meat.

The treatment chamber 24 If possible, it is largely hermetically enclosed, for example by a partition 34 and an air duct wall 36 , The air guide wall 36 is substantially through the shell 22 of the extract 18 educated. The partition 34 is in the embodiment according to 1 on the housing 12 formed and / or fixed. In other words, forms the partition 34 an upper end wall.

Essential for that in the device 10 Used preparation method is the provision of flow channels for the treatment fluid, in particular for the heated air. The interior 30 of the insert 26 is surrounded by a circumferential gap 38 which is designed like a coat-like. Further, an upper space 40 is provided between the partition wall 34 and the mission 26 is trained. Next to it is a lower gap 42 formed between the lower part 14 facing portion of the shell 22 and one of these opposite bottom surface of the insert 26 is trained. The gaps 38 . 40 . 42 preferably surround or enclose the insert 26 completely or almost completely.

Furthermore, for example, at least one floor 44 the wall 28 the insert 26 sieve-like or net-like design, further wherein the use 26 is open in the treatment chamber 24 upwards. Accordingly, the in 1 indicated by arrows flow pattern for the treatment fluid, which is similar to the course of field lines of an electromagnet. With others In words, the flux lines as a whole define a roughly torus-shaped body.

For heating the treatment fluid is a heating unit 46 provided with a ventilation unit 48 is coupled. The heating unit 46 comprises at least one heating element 52, for example in the form of a resistance heater.

The ventilation unit 48 includes a drive 54 who has a motor 56 , in particular an electric motor. The drive 54 is about a wave 58 coupled with a ventilation wheel 60. The ventilation wheel 60 is by the engine 56 of the drive 54 over the wave 58 driven. The ventilation wheel 60 generates the fluid flow in the treatment chamber 24 of the device 10 , compare with 64 marked arrows.

The flow 64 happens the heating element 52 the heating unit 46 and is thereby warmed up in the desired manner in order to carry out the heat treatment of the food.

The ventilation wheel 60 is between the drive 54 and the heating element 52 arranged. The ventilation wheel 60 and the heating element 52 are exposed to fluid flow. Preferably, the drive 54 , especially the engine 56 , arranged such that no contact with the fluid flow takes place. This preferably also applies to further electrical and / or electronic components of the device 10 ,

In 1 is also indicated by a baffle 62, which contributes to the directed flow guidance. The baffle 62 joins an upper edge of the basket-like or cup-like wall 28 of the insert 26 at. In the baffle 62 is formed an opening through which the flow 64 can pass through.

This in 1 shown ventilation wheel 60 sucks axially and blows out radially. It is understood that this design is merely exemplary in nature.

For flow guidance is exemplary in the bottom area of the shell 22 arranged a guide element 68, which is a suitable deflection of the flow 64 through the treatment chamber 24 and toward the heating element 52 and the ventilation wheel 60 causes. Other elements for flow guidance can be provided.

Furthermore, the in 1 Illustrated exemplary embodiment of the device 10 at least one sensor 72 on top of that in the treatment chamber 24 or at least the treatment chamber 24 is arranged adjacent. At the sensor 72 it can be a temperature sensor, a pressure sensor, a humidity sensor or a combined sensor.

Furthermore, the device 10 a vent 74 which serves to provide any overpressure in the treatment chamber 24 dismantle. To a pressure increase in the treatment chamber 24 It can basically come through the temperature increase. This may also include an aggregate state change, such as vapor formation. In this respect, the ventilation is used 72 for pressure regulation in the treatment chamber 24 ,

For purposes of the present disclosure, a subdivision is made in the components of the device 10. The device 10 has a first area 78, which may also be referred to as a hot area or hot air area. Further, a second area 80 provided, which can also be referred to as cold air or cold area. The first area 78 includes primarily the treatment chamber 24. The first area 78 is also the heating element 52 assigned. Next to it is also the ventilation wheel 60 in the first area 78 arranged. The first area is through the shell 22 and the partition 34 limited and sealed as possible to the outside or thermally and / or fluidically isolated.

In the first area 78 it comes during the heat treatment of food to a significant increase in temperature. It also takes place in the first area 78 a flow or flow around with the treatment fluid instead. The treatment fluid may have increased moisture and possibly even fat components and / or oil components.

The second area 80 is preferably sufficient from the first area 78 isolated. In the second area 80 electrical and / or electronic components of the device 10 are arranged. For example, at least the engine 56 of the drive 54 in the second area 80 arranged. Preferably, the second area 80 sufficiently from the first area 78 separated, so that a transfer of the treatment fluid is largely prevented in the second area. This has beneficial effects on the reliability and life of the electrical / electronic components operating in the second area 80 are arranged.

Generally, in the second area 80 Control technology for the device 10 may be arranged. Such a control unit may be coupled to an operator interface 86, which is also the second area 80 assigned.

The present disclosure addresses measures for improving the seal between the first area 78 and the second area 80 , Between the first area 78 and the second area 80 is at least one opening 82 formed in the dividing wall 34 is provided. The wave 58 that the drive 54 connects with the ventilation wheel 60, passes through the opening 82 , The opening 82 is thus basically for the transfer of the treatment fluid from the first area 78 in the second area 80 susceptible.

Hereinafter, measures for increasing the sealing effect at the opening 82 will be explained and illustrated in more detail.

First, it will open 2 With reference to a partially exploded perspective view of a basic layout of another embodiment of a device 110 for the treatment of food. Functionally, the device is 110 the in 1 shown device 10 at least similar. The device 110 has a housing 112 on which surrounds a treatment chamber 124. Further, an excerpt 118 provided to access the treatment chamber 124. About the extract 118 that has a handle 120 can be operated, a shell 122 from the treatment chamber 124 be removed. The shell 122 carries an insert 126 who has an interior 130 Are defined. The insert 126 is approximately basket-like or sieve-shaped, depending on the desired type of heat treatment.

For use of the device 110 will be the use 126 in the bowl 122 added. Together, the shell 122 and the use 126 about the extract 118 in the treatment chamber 124 introduced. For this purpose is the extract 118 a pushing unit 132 is provided.

An actuation of the device 110 can be done about an operator interface 186, which includes about a display. Further, the operator interface 186 may include input elements.

With reference to the 3 to 6 Another exemplary embodiment of a food preparation apparatus, generally designated 210, is illustrated. Basically, the device 210 functionally and structurally the devices 10 . 110 at least similar.

3 shows a sectional view through the device 210 , 4 and 5 each show enlarged partial sectional views of components of the device 210 , 6 shows an exploded perspective view of components of the device 210 , in the 4 are shown cut.

The device 210 has a housing 212 on, that is a lower part 214 as a base and a top 216 having. Further, an excerpt 218 provided, which is actuated by a handle 220.

About the extract 218 can a bowl 222 from a treatment chamber 224 in the case 212 be removed. In the bowl 222 is an assignment 226 taken, which is designed pot-like or cup-like. The use 226 defines an interior 230 , In the interior 230 Food can be absorbed and shared with the use 226 and the shell 222 in the treatment chamber 224 be introduced.

The Bowl 222 is on its top a partition 234 assigned. As already mentioned above in connection with in 1 illustrated embodiment, separating the partition 234 a first area 278 from a second area 280. The first area 278 can also be referred to as a hot air area. The second area 280 can also be referred to as cold air area. Together, define the shell 222 and the partition 234 the first area 278 , The partition 234 is designed for example as part of a shielding plate, which is designed approximately as a sheet metal cup (see the reference numeral 298 in 6 ). The shielding can be produced for example by means of deep drawing or a similar kind of manufacturing process, whereby a favorable flow-optimized contour can be generated. The first area 278 further provides a space in which the treatment chamber 224 is trained.

In principle, already described above manner is the use 226 of spaces 238 . 240 . 242 surrounded, which serve to air guidance. The gap 238 surrounds a peripheral region of the insert 226 , The gap 240 joins an upper area of the insert 226 at. The upper gap 240 is between the partition 234 and the mission 226 educated. The gap 242 joins a lower part of the insert 226 at the bottom 214 the housing 212 faces.

The use 226 is approximately basket-like or sieve-shaped and has at least one perforated or apertured bottom 244 to allow a flow through the treatment fluid.

The device 212 includes a heating unit 246 and a ventilation unit 248. The heating unit 246 includes at least one heating element 252 , which is designed as a resistance heater. The ventilation unit 248 includes a drive 254 , the at least one engine 256 includes. The motor 256 is about a wave 258 with a ventilation wheel 260 coupled. The ventilation wheel 260 is between the partition 234 and a baffle 262 arranged. The ventilation wheel 260 will be over the shaft 258 through the engine 256 driven. The baffle 262 defines an opening. The ventilation wheel 260 is the opening in the baffle 262 facing. The ventilation wheel 260 is designed to suck air axially and blow it out radially. The sucked air flows through the heating element 252 and is heated by it. The radially blown heated air flows through the spaces 240 . 238 . 242 to get over the ground 244 in the interior 230 of the insert 226 enter. There, the air can heat up ingested foods before they turn the heating element 252 flows through when coming from the ventilation wheel 260 is sucked.

To optimize the air flow is in a bottom area of the shell 222 at least one guiding element 268 arranged, which deflects the fluid flow in a favorable manner. The partition 234 forms a border between the first area 278 and the second area 240 , The wave 258 protrudes through an opening 282 the partition 234 , compare too 6 , Thus, in the area of the shaft passage through the partition wall 234 basically with an undesirable transfer of the treatment fluid from the first region 278 into the second region 280 to count. This danger can be counteracted by appropriate countermeasures.

The wave 258 according to the in 3 In any case, the embodiment shown is in the first area 278 stored on the fly. In other words, the wave 258 exclusively in the second area 280 indirectly or directly on the housing 212 the device 210 recorded. For example, for this purpose, a first camp 290 and a second camp 292 provided, each one end of the engine 256 assigned. In other words, the wave forms 258 a rotor of the motor 256 , Accordingly, the bearing of the rotor also forms the bearing of the shaft 258 , This has the advantage that in the first area 278 which is exposed to elevated temperatures, increased humidity, vapors and the like, no storage is provided. This also has favorable effects on the flow path, since the flow resistance in the first region 278 can thus be reduced. Would in the first area 278 a bearing for the shaft 260 may be provided, this storage would be exposed to unfavorable conditions.

In the 3 embodiment shown further comprises a fan 294 that is used to cool the engine 256 serves. The fan wheel 294 is the second area 280 , ie the cold air area, assigned. The fan wheel 294 is between the partition 234 and the motor 256. The partition 234 extends between the fan 294 and the ventilation wheel 260 , The lack of additional storage in the area of the fan 294 and / or the ventilation wheel 260 also allows a compact design of the ventilation unit 254 in the axial direction.

With particular reference to the 4 . 5 and 6 is an exemplary embodiment of the passage of the ventilation unit through the partition 234 illustrated.

The wave 258 and non-rotatably received components are relative to the partition 234 around a longitudinal axis 296 rotatable. In other words, there is in the area of the opening 282 ( 6 ) of the partition 234 a relative movement between the shaft 258 and the housing-fixed partition wall 234 , To seal the passage through the partition wall 234 is a labyrinth seal 304 proposed, which can also be referred to as a gap seal.

The sealing effect of the labyrinth seal 304 is based on an extension of the flow path 306 through the seal. In other words, the labyrinth seal 304 increases the flow resistance, resulting in a sufficient seal. The labyrinth seal 304 is designed contactless. In other words, the labyrinth seal includes 304 rotatable and solid components that do not contact each other.

The flow path 306 through the labyrinth seal 304 shows in comparison to the pure axial extent of the labyrinth seal 304 a longer length.

The labyrinth seal 304 provides a good compromise from tolerances required for the passage through the partition even with a flying mounting of the ventilation wheel 260 234 and the achievable sealing effect.

In the enlarged view according to 5 For example, a flow channel resulting for the flow path 306 is designated 308. Preferably, the flow channel 308 has a sufficiently small gap to achieve the desired sealing effect. The thickness of the gap is in 5 denoted by d.

In the in the 3 to 6 illustrated embodiment, the shaft 258 is designed in several parts. The wave 258 includes a shaft 310 that too with the rotor of the engine 256 coupled, compare 3 , The shaft 310 is over a thread 332 with a connector 312 coupled, which can also be referred to as a socket. The connector 312 is with another connector 314 coupled, which may also be referred to as a socket. The connection between the connecting pieces 312, 314 via a thread 318 , Between the connecting pieces 312, 314 is the fan 294 taken and over a disc 320 rotationally clamped.

At the connector 314 is over a thread 322 A mother 316 absorbed, the axial completion of the shaft 258 forms. Between the connector 314 and the nut 316 is a slice 324 added. The disc 324 contacted an end wall 326 the ventilation wheel 260 and clamps them against the connector 314.

The labyrinth seal 304 includes a housing portion 328 which can also be called a solid section. Furthermore, the labyrinth seal includes 304 a shaft portion 330, which may also be referred to as a movable portion. The housing portion 328 and the shaft portion 330 rotate relative to each other when the shaft 258 is driven.

The housing section 328 includes a collar 334 , preferably as an extension of the partition wall 234 is trained. In other words, the collar 334 in the production / transformation of the shielding plate 298 that is the dividing wall 234 is formed, integrally and without substantial additional effort to be generated. The collar 334 extends in the direction of the ventilation wheel 260 , ie towards the first area 278 ,

The shaft section 330 of in 5 illustrated embodiment of the labyrinth seal 304 includes a cylindrical disc 338 in the assembled state between the disc 324 and the connector 314 taken up and clamped over the nut 316. The cylinder disc 334 includes a collar 340 which is opposite the collar 334. The collar 340 extends toward the second region 280. The collar 340 surrounds the collar 334 , The collar 334 surround the shaft 258 , in particular the connector 314 the wave 258 ,

The collar 334 forms a cylinder wall 344 out. The collar 340 forms a cylinder wall 346. Deviating from the collar 334 . 340 basically be conical or in a similar manner as a rotational body with a circumferential cross section. It is understood that the labyrinth seal may have further elements for extending the flow path to further increase the flow resistance, so for example more fixed collar, which are coupled to other movable collar. If possible, the flow channel 308 designed such that there is a plurality of deflections for the fluid. In this way, the flow resistance can be further increased.

6 shows an exploded perspective view of the in 5 in enlarged sectional view illustrated components. With a few additional components, the labyrinth seal 304 be realized without significantly increasing the production costs. The housing section 328 the labyrinth seal 304 is preferably as a collar 334 integral with the partition 243 executed. The shaft section 330 is preferably as a simple cylindrical disk 338 Running, with a circumferential collar 340 is provided.

Alternatively, the shaft section 330 with the surrounding collar 340 also as an integral part of the ventilation wheel 260 be creative.

While embodiments of the present disclosure have been described and illustrated herein, various other means and / or structures are readily envisioned by one of ordinary skill in the art to effect the functions and / or results and / or one or more of the advantages described herein, and each Such variations and / or modifications are considered to be within the scope of the present disclosure. Further, it will be readily apparent to those skilled in the art that all parameters, dimensions, materials, and embodiments described herein are to be exemplary, and that the actual parameters, dimensions, materials, and / or designs may vary depending on the particular application or specific applications for which The teachings of the present disclosure may be used.

One skilled in the art will recognize or may determine many equivalents to the specific embodiments of the disclosure described herein by not more than experimenting routinely. It is therefore to be understood that the foregoing embodiments are provided by way of example only and that the disclosure within the scope of the appended claims and equivalents thereof may be practiced otherwise than as specifically described and claimed. The present disclosure is directed to all individual features, systems, articles, materials, equipment, and / or methods described herein. In addition, any combination of two or more of such features, systems, articles, materials, equipment, and / or methods is within the scope of the present disclosure, unless such features, systems, articles, materials, equipment, and / or methods are not mutually exclusive.

All definitions, as defined and used herein, should be understood to precede dictionary definitions, definitions in documents incorporated by reference, and / or ordinary meanings of the defined terms are relevant.

The indefinite articles "a" and "an" as used in the disclosure and claims herein, unless otherwise clearly indicated, are to be understood as meaning "at least one".

The phrase "and / or" as used in the specification and claims herein is to be understood to mean "one or both" of the elements associated herein, i. H. of elements that in some cases are present as subjunctive and in others disjunctive. Other elements may optionally be present in addition to the elements expressly named by the "and / or" formulation, whether or not they refer to the expressly recited elements, unless clearly stated otherwise.

In addition, any reference numbers in the claims are not to be understood in a limiting sense.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• WO 2012/168897 A1 [0003]

Claims (15)

Apparatus (10, 110, 210) for preparing foodstuffs, in particular by means of hot air, comprising a housing (12, 112, 212), a treatment chamber (24, 124, 224) formed in the housing (12, 112, 212), a heating unit (46, 246) for heating a treatment fluid which during operation flows through the treatment chamber (24, 124, 224), - A ventilation unit (48, 248) having a drive (54, 254) and a Ventilationsrad (60, 260), which are coupled together via a shaft (58, 258), wherein the ventilation wheel (60, 260) is arranged in a first region (78, 278) through which the treatment fluid flows, wherein the drive (54, 254) is arranged in a second region (80, 280) which is separated from the first region (78, 278) by a dividing wall (34, 234), wherein the shaft (58, 258) extends through an opening (300) in the dividing wall (34, 234), and wherein at the opening (300) a labyrinth seal (304) is formed, which extends between the shaft (58, 258) and the partition (34, 234). Device (10, 110, 210) after Claim 1 wherein the labyrinth seal (304) defines a flow path (306) between the first region (78, 278) and the second region (80, 280), the length of which is at least two times, preferably at least three times, more preferably at least five times an axial length Extension of the labyrinth seal (304) is. Device (10, 110, 210) after Claim 1 or 2 wherein the labyrinth seal (304) has a flow channel (308) with a circumferential cross section with at least one directional deflection, preferably with at least two directional deflections. Device (10, 110, 210) after Claim 3 wherein the flow channel (308) comprises a circumferential gap of preferably S-shaped or Z-shaped cross-section. Device (10, 110, 210) according to one of Claims 1 to 4 wherein the labyrinth seal (304) comprises at least one shaft-side portion (330) and a housing-side portion (328) that are rotatable relative to each other when the shaft (58, 258) is driven. Device (10, 110, 210) after Claim 5 wherein the shaft-side portion (330) is rotatable relative to the housing-side portion (328) without contact. Device (10, 110, 210) according to one of Claims 1 to 6 wherein the partition wall (34, 234) between the first region (78, 278) and the second region (80, 280) comprises a shielding plate (298) forming the opening (300), preferably a deep-drawn shielding plate. Device (10, 110, 210) according to one of Claims 1 to 7 wherein the labyrinth seal (304) has a fixed collar (334) formed as part of the dividing wall (34, 234) and surrounding the opening (300). Device (10, 110, 210) after Claim 8 wherein the fixed collar (334) extends from the dividing wall (34, 234) toward the first region (78, 278). Device (10, 110, 210) according to one of Claims 1 to 9 wherein the labyrinth seal (304) comprises a rotatable collar (340) rotationally connected to the shaft (58, 258) and extending toward the second region (80, 280). Device (10, 110, 210) according to one of Claims 1 to 10 wherein the labyrinth seal (304) has two interlocking circumferential cylinder walls (344, 346), wherein a first cylinder wall (344) is associated with the partition (34, 234) and a second cylinder wall (346) is associated with the shaft (58, 258) the second cylinder wall (346) surrounds the first cylinder wall (344), and wherein the first cylinder wall (344) surrounds the shaft (58, 258). Device (10, 110, 210) according to one of Claims 1 to 12 , wherein in addition to the Ventilationsrad (60, 260) further comprises a fan (294) for cooling the drive (54, 254) is provided, which in the second region (80, 280) on the shaft (58, 258) is received and between a Motor (56, 256) of the drive (54, 254) and the partition wall (34, 234) is arranged. Device (10, 110, 210) according to one of Claims 1 to 13 in which the shaft (58, 258) is mounted in the second region (80, 280), wherein in the first region (78, 278) a flying bearing results, and wherein the shaft (58, 258) in particular the opening (300) in the partition wall (34, 234) extends without contact. Device (10, 110, 210) according to one of Claims 1 to 14 wherein the device (10, 110, 210) is configured using the labyrinth seal (304) as a hot air fryer or dry fryer.

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