GB2123220A

GB2123220A - Fan drive motor

Info

Publication number: GB2123220A
Application number: GB08314922A
Authority: GB
Inventors: Heinz Wieland
Original assignee: Wilhelm Gebhardt GmbH
Current assignee: Wilhelm Gebhardt GmbH
Priority date: 1982-07-03
Filing date: 1983-05-31
Publication date: 1984-01-25
Also published as: FR2529723A1; SE8301540D0; DE3224975A1; GB2123220B; SE8301540L; GB8314922D0; FR2529723B1

Abstract

A drive motor for a fan has a pot-like housing within which the stator of the motor is placed with a small amount of clearance of a force fit. The housing has an attachment flange (18) formed thereon for joining the motor to a fan housing (10). Impellers (24 and 26) designed for use with the motor have a cup-like end plate (28) so as to have enough space to take up the housing (40) of the drive motor (16). <IMAGE>

Description

SPECIFICATION A driving motor for a fan The invention is with respect to driving motors for fans and more specially to such a motor having a housing and stator and a rotor.

Motors designed for use as built-in motors in fans in ventilating and air conditioning systems have to be very compact so that driving motors with a high power to size ratio are preferred. Furthermore driving motors for fans have to be designed so that they may be generally run without upkeep and so as to be be troublefree in operation. This only becomes possible if the impeller is directly driven by the drive motor; drive motors joined up with the impeller by way of belts take up overly much space and are not troublefree.

Generally speaking, the drive motors used for fans have so far been inner rotor motors that are placed partly within the fan impeller and are then fixed to a side wall of the fan housing by sheet metal struts.

This design has some shortcomings more specially in the case of fans with the intake of air on both sides of the fan, because the means for supporting the motor is in the way of the intake air current and makes for a lower efficiency.

External rotor and plate or disk rotor motors are used less widely, the rotor then being able to be used as the hub of the fan or blower impeller at the same time. However, such forms of drive motor are high in price, seeing that they are customized designs produced in small production runs, and the fans units fitted therewith are then not competitive in price.

It is for this reason that one purpose of the invention is that of designing a fan drive motor that may be used as a part of very compact fan units while nevertheless being able to be produced using commercial motor part sets and being able to be fully adapted to the most different fan designs.

For effecting this and further purposes that will become clear on reading further parts of the present specification, a drive motorforfans in keeping with the present invention is characterized in that the housing is in the form of a thin-walled part placed round the stator with a small clearance therebetween and has an attachment flange formed thereon.

In the motor of the present invention the pot-like housing is placed round the statorwith a very small or no play so that the housing at the same time may have the function of conducting heat away from the motor. This being the case, the motor does not for its part have to have any cooling fan impeller of its own, this being of value in making the design as compact as possible. When the motor is being used the cooling of the pot-like housing will take place directly by way of the air current moved by the fan.

Furthermore the presence of the attachment rim or flange will give the housing a high mechanical strength even with its thin wall, the attachment rim being able to be used at the same time for fixing the drive motor in position on the housing of a fan.

Useful further developments of the invention are to be seen in the claims.

A detailed account of working examples of the invention using the accompanying Figures will now be given.

Figure 1 is an axial section taken through a fan with air intake on both sides thereof.

Figure 2 is an axial section taken through a further form of fan.

Figure 3 is an axial section taken through a still further form of fan.

Figure 4 is an axial section taken through the drive motor of the fan to be seen in Figure 1.

Figure 1 is a view of part of a fan housing generally numbered 10, that has two air intake openings 12 and 14 that are placed opposite to each other.

An electric motor 16 is fixed in position by way of an attachment flange 18 placed round it and by way of a support wall 20 with the fan housing 10. On the two ends of the motor shaft 22 two impellers 24 and 26 are keyed, that have a bell-like or hollow frustoconical end plate or hub 28 with the impeller blades 30 running out from it to have their outer ends joined to a ring 32. The hub 28 has a hub core part 34 fixed thereto, that for its part is keyed on the motor shaft 22.

As is to be seen in Figure 4, the electric motor 16 has a rotor 36, a stator 38 and a housing 40 whose end plates have bearings for supporting the motor shaft 22.

The housing 40 is made up of two like housing parts 44 and 46 facing each other so as to be fully symmetrical about a plane between them and which are produced by deep drawing sheet metal. At its axially inner end each of the housing parts 44 and 46 has an end flange running round it as marked at 48 in the one case and 50 in the other. The end flanges 48 and 50 are fixedly joined together, for example by spot welding for together forming the attachment flange 18.

As will be seen from the Figure, the housing 40 is placed round the stator 38 of the electric motor with only a small amount of play, or if desired the stator 38 may be placed in the housing 40 with a force or press fit. In the form of Figure 4, the electric motor 16 does not have any separate cooling fan impeller of its own and in fact the heat produced in operation is conducted away directly by the air current produced by the fan by way of the housing 40.

Figure 2 is a view of a fan with air intake on only one side of the fan. Parts thereof that are the same as parts as detailed earlier in connection with Figure 1 are given the same part numbers.

The electric motor 16' as well has a two-part housing 40', that is made up of a left hand housing part 44 and a right hand housing part 46' that is smaller in the axial direction. The attachment flange 18 is screwed in place directly on the wall, to be seen on the left in the Figure, of the fan housing 10.

Figure 3 is a view of a further fan with some changes and with air intake on one side of the impeller, parts that are the same in function as the parts noted hereinbefore having the same part numbers.

The electric motor 16" this time has a housing 40", that is made up of a housing 46 and a flat end plate 52, the same supporting the second shaft bearing and having an outer diameter the same as the diameter of the end flange 50.

The Figures will make it quite clear that the fans as detailed are characterized by a having a compact structure and that by making only small changes a standard electric motor may be used for fans with air intake on one or both ends or sides of the fan. This makes it possible for the most important parts of the fans to be produced in large numbers so that all the different sorts of fans may be produced at low prices simply by making up different combination of the parts.

From this it may be seen that the present invention has to do with an electric motor with a special design of the housing for use as a built on or built in drive for fans and fan impellers, more specially for use in ventilating and air conditioning systems and for roof ventilators as well for example. Fans for such purposes have in the last few years been designed in simpler and simpler forms and furthermore been made lighter because of the pressure of competition and of prices. Because of the very limited amount of space dn hand most attention has been given to specially compact fans with a high power to size ratio. Furthermore the fans have to troublefree in operation and to be able to run without needing upkeep. This purpose may only be effected by using directly driven fans and not by those driven by belts.

Taking into account all these points the purpose of the present invention is to be that of overcoming the undesired effects of known designs and of producing drive units for fans, that make a compact structure possible, that may be manufactured using commercial motor construction sets that are produced in large numbers, that are low in price and furthermore may be changed as desired for matching them to the different forms of fan.

This purpose is effected inasfar as the current commercial motor part sets are used made up of an inner rotor and an outer stator with the winding thereon, the motor have its own specially outer housing. This outer housing is so designed that it is only a little larger than the stator so that the overall size of the motor is as small as possible. The bell- or pot-like housing may be produced of drawn sheet metal or by casting. The only important point in this connection is that the size is only a little greater than that of the stack of laminations and the winding. In this respect the motor may be made up of two pot-like housing parts, that have the same overall length or may be of different depth. It would furthermore be possible for the housing to be made up of only one pot-like part and a further flat disk and the end thereof.The pot-like housing part has a rim running round it, that may be used as an attachment flange or which may be joined up by struts with the outer edge of the housing and on the fan housing. A further point about this drive motor is not having air cooling blades, as otherwise generally used, for the motor. Because of the very closely fitted motor housing and because the motor is placed at least indirectly in the air current of the fan, it is possible to do without such a separate cooling fan and then make the motor more compact. The fixing of the stack of stator laminations in the pot-like housing parts is, in the case of small sizes, best made permanent, as for example by pressing the stack into the pot-like housing, although in this respect the design might be different.

At any event an important point is the design of the housing with an attachment rim or lip and the adaptability. Figure 1 herein is a section through a fan with air intake on both sides of the fan, in the case of which the pot- or bell-like housing part of the drive motor are equally deep and the fan housing is joined therewith by connection struts. However, it would in this case be possible to have a continuous separating wall. On the other hand the fan of Figure 3 is designed for air intake on both sides of the fan, the driving motor being joined at one of its ends by a flange with the housing wall and the motor housing is made up of only one bell-like part and a disk-like cover. Figure 2 herein is a view of a fan with air intake on one side of the impeller only, the driven motor being placed so that part of it is within the body of the impeller. The motor housing is made up of two bell- or pot-like parts drawn to different depths. On the other hand Figure 4 is a section through a drive motor in keeping with the invention having its housing made up of two bell-like parts of equal depth. The outline of the housing at the bearing parts is only to be taken as one possible example and many other forms are in fact possible.

Furthermore the motor may have one or two driving shaft ends.

Claims

1. Afan impeller drive motor comprising a housing, a motor stator and a rotor, the stator located within said housing with a minimum clearance therebetween, and the housing being in the form of a thin-walled structure with an attachment flange formed thereon.

2. A fan impeller drive motor as claimed in claim 1, wherein the housing is formed of two housing parts each of which has an end flange, and the parts having the end flanges in contact to define the attachment flange.

3. Afan impeller drive motor as claimed in claim 2, wherein the housing parts are pot-like.

4. Afan impeller drive motor as claimed in claims 2 or 3, wherein the housing parts have the same size.

5. Afan impeller drive motor as claimed in claim 2 or 3, wherein one of the housing parts has a very much greater axial size than the other of the housing parts.

6. Afan impeller drive motor as claimed in claim 1, wherein the attachment flange is located at one axial end of the said housing.

7. Afan impeller drive motor as claimed in any of the preceding claims, wherein the housing is made of drawn sheet metal.

8. Afan impeller drive motor as claimed in any of the preceding claims, wherein the stator is press fitted into the housing.

9. Afan comprising a drive motor as claimed in any of claims 1 to 5, and an impeller with a bladed impeller end plate, the end plate being bell-like and being placed round at least an end part of the housing of the drive motor.

10. A fan as claimed in claim 9, wherein the end plate is frusto-conical.

11. Afan impeller drive motor substantially as hereinbefore described with reference to Figures 1 and 4 of the accompanying drawings.

12. Afan impeller drive motor substantially as hereinbefore described with reference to Figure 2 of the accompanying drawings.

13. Afan impeller drive motor substantially as hereinbefore described with reference to Figure 3 of the accompanying drawings.