NL8001320A - Ventilation fan for hot air circulation - has convex hot air wheel to reduce axial length, and includes screw cap to permit wheel to be removed for cleaning - Google Patents

Abstract

The ventilation fan for hot air circulation has a very short axial length to allow mounting in an air outlet. This is achieved by making the hot air wheel of convex shape. A fan blade wheel has blades (6 or 7) which are chosen to suit the application. The motor shaft (10) carries an axial rotor wheel (11) which provides cooling of the motor and its mounting plate (5). For built in outlets with a double fan the radial wheel (7) with a spiral casing (8) provides cooling of the envelope. A screw cap (9) on the rotor shaft allows the hot air wheel (1) to be removed for cleaning purposes. This wheel has a convex form which commences in the area of the blades and continues to the exterior. Pref. the hot air portion of the circuit is a one-piece stamping, made of stainless steel, or an aluminium casting.

Description

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Hot air blower

The present invention relates to a hot air blower.

Such hot air blowers are necessary, for example, for air circulating fireplaces and consist of an electric motor, preferably a motor with an external rotor, with a corresponding shaft end for accommodating a hot air wheel.

In the known embodiments, considerable space is required in the axial direction. With hot air blow units it is especially important to keep these units very short. Even a space saving of a few millimeters already represents a very considerable advantage here, because it makes it possible to shorten the entire system of, for example, the fireplace with air circulation. In the future it is desired to provide a front plate lying flush with the kitchen furnace at a certain distance in front of the door of the oven. As a result of the construction of the same size of the hot air blower, the muffle furnace would become even smaller, which would mean new muffle tools for the fireplace manufacturer, which are relatively expensive.

The object of the present invention is to provide a hot air blower 20 and 20, respectively. provide a hot air blower unit with the shortest possible axial construction length.

This object is achieved in that according to the invention the hot air wheel is convex, the convex according to the invention meaning; seen from the engine unit.

Another inventive idea is that the rear wall of the muffle furnace is also convex, preferably equal to, at least substantially the same as the embodiment of the A hot air wheel.

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Another aspect of the invention must be seen herein, the external contours of the drive unit, so the example of the motor with external rotor including the radial wheel and the like, also at least on the side of the rear wall of the muffle furnace to this convex shape. to fit.

Cores of all possible embodiments are considered convex shapes, e.g. an arc shape, an arc shape which may be delimited in the middle part by a flat surface, for example, or a U shape, respectively. a U-shape, the legs diverging in the direction of the motor unit; here the transitions (all seen in cross-section) from the legs to the middle section can be arcuate, respectively. this U-shape can also be modified such that the so-called bottom surface is also arched. The contours of the other construction parts must be made equal to the above contours as much as possible; 15 here, for example, the shape of the motor mounting plate, that of the insulation, that of the rear wall of the muffle furnace, that of the hot air wheel (at least in the essential middle section), etc. have been considered.

Furthermore, it is an object of the invention to keep the motor shaft as short as possible; this can be done by the fact that the hot air wheel is bent back inwards towards the motor at its attachment to the motor shaft, of course only to the extent that this results in the short construction length of the entire system, which is intended according to the invention, is not adversely affected.

The invention will be further elucidated with reference to the drawing with a few exemplary embodiments of a hot air blowing unit, which is in principle drawn in cross section.

On the left side of the drawing an external rotor motor with its mounting is shown; this embodiment is known in principle; dashed-dotted lines on the left show the extent to which the hot air blowing unit projects outwards in the known embodiments. According to the invention, an axial length of, for example, 25 mm is saved here. This saving is very significant.

35 In this connection, it should be noted that the capacity in respect of the signed establishments is not diminishing; with the embodiment of the hot air blower according to the invention, even a more favorable outflow of air can be achieved with an improved efficiency or efficiency.

Two design variants I and II have been drawn, namely for different embodiments of fan wheels 6 and 7, which have proved to be particularly advantageous for the hot air blower according to the invention. The motor and the motor mounting plate 5 are cooled by the axial wheel 6 mounted on the rotor. For built-in or 10 built-in fireplaces (variant II) with a double blower, the radial wheel 7 with spiral-shaped housing 8 serves to cool the casing.

The end 10 of the motor shaft, which is very short in accordance with the invention, is fitted to cap nut 9 or a similar fastening member. This has proved to be effective, because by loosening the hot air wheel 1 in the cap nut it is easy to disassemble it for cleaning.

According to the invention, the convex shape of the hot air wheel is particularly important. 1. The convex shape can already start at the blades, then it is outwards, to the right, lined and at the. 20 an exemplary embodiment in the vicinity of the motor shaft 10 is again slightly bent back to the left and designed directly at the location of the mounting surface. Thanks to this measure according to the invention, the motor shaft 10 can be made very short; however, this turn-back to the left is not absolutely necessary.

The motor mounting plate 5 is also correspondingly formed and, in addition, the motor with external rotor, possibly with its axial fan wheel.

The heat transfer goes from the hot air fireplace via the motor shaft 10 to the rotor 11; there the heat is dissipated to the environment by supplying fresh air via the fan wheel 6, 7; this also achieves considerable advantage.

When, according to the invention, the central part of the hot air wheel 1 is spoken of, the part of the drawing which is bent to the right is intended.

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Claims (16)

Hot air blower, especially for fireplaces with air circulation, characterized in that the hot air wheel (1) is convex. Hot air blower according to claim 1, characterized in that the rear wall (3) of the muffle furnace is convex. Hot air blower according to claim 1 or 2, characterized in that the convex shape as a high shape or partial arc shape, as a U shape (cup shape), as a U shape with inwardly diverging legs (with 10 or without concave protrusion) or the like is carried out. Hot air blower according to at least one of the preceding claims, characterized in that the convex shape is arranged in the central part of the hot air wheel (1). Hot air blower according to at least one of the preceding claims, characterized in that the convex shape of the hot air wheel (1) and of the rear wall (3) of the muffle furnace is essentially the same to parallel (extending). Hot air blower according to at least one of the preceding claims, characterized in that the hot air wheel (1) is rectilinear in the region of the fastening bore. Hot air blower according to at least one of the preceding claims, characterized in that the hot air wheel (1) is concave curved in the region of the fastening bore. Hot air blower according to claim 1, characterized in that at least the external contours of the drive unit, in particular the external rotor motor including the radial wheel, have a convex shape, preferably essentially with the convex shape of the hot air wheel (1) have been implemented accordingly. Hot air blower according to at least one of the preceding claims, characterized in that the hot air wheel (1) is preferably punched or made in one piece from stainless steel. deep drawn. Hot air blower according to at least one of the preceding claims, characterized in that the hot air wheel (1) is easily detachable by means of a cap nut (9). Hot air blower according to at least one of the preceding claims, characterized in that an axial wheel (6) for cooling the motor and the motor mounting plate (5) is arranged on the rotor. Hot air blower according to at least one of the preceding 5 claims, characterized. by two separate ventilation systems (variant II), in which the radial wheel (6) mounted on the rotor rotates, for example, in a spiral housing (8), Hot air blower according to at least one of the preceding claims, characterized in that one motor, in particular an external rotor motor, is arranged for two ventilation systems. 1i +. Hot air blower according to at least one of the preceding claims, characterized in that the radiant heat penetrating through the insulation (b) to the motor mounting plate (5) and the like is not transferred to the motor, but through the circulating air of at least one fan wheel ( 6, j) is discharged into the environment. Hot air blower according to at least one of the preceding claims, characterized in that the motor shaft (10) is designed as a very short stub shaft. Hot air blower according to at least one of the preceding claims, characterized in that, in the penetration area of the motor shaft (10), the wall thickness of the rear wall (3) of the muffle furnace, including the insulation (U). made smaller. Hot air blower according to at least one of the preceding claims, characterized in that the hot air wheel (1) is made of aluminum by compression molding, 18. Hot air blower, substantially as described in the description and / or shown in the drawing. © 800 1 3 20