Fan Assembly For A Ventilator

Abstract

A fan assembly for a ventilator, and a square ventilator housing comprising a first portion formed with a first passage of circular cross-section and wherein the fan assembly is at least partially received, and at least one second portion rigid with the first portion and formed with a second passage axially aligned and directly communicating with said first passage, said second passage having an open end spaced from the first passage and having throughout its length and at the open end thereof a cross-sectional area greater than the cross-sectional area of the circular first passage and a transverse dimension greater than the diameter of the circular first passage. The electronic components as resistors, condensors, transistors, diodes and the like which are necessary for commutation and/or for electrical control of this fan assembly are placed inside one or more hollow portions in the corners of said square housing.

Description

BACKGROUND OF THE INVENTION

The present invention relates to a fan assembly for a ventilator. More particularly, the invention relates to improvements in a fan assembly which may be utilized for ventilation and efficient withdrawal of heat from electrical apparatus, for example, for cooling of apparatus which are used in the field of communications. Still more particularly, the invention relates to improvements in a fan assembly wherein the rotor preferably accommodates the stator.

There is an increasing tendency to control the amount of air-flow through said equipment depending from temperature, humidity or other parameters. This can be done easily by electronic control of the speed of the fan.

It is therefore a primary object of the present invention to provide a fan of small size and high capacity by housing the electronic components which are necessary for said electronic speed control in spare room inside the housing of the fan assembly.

It is a further object of the invention to provide a simple and inexpensive fan assembly in which the motor may easily be replaced by a like one.

It is a still further object of the invention to provide an efficient cooling of such electronic components in which heat is generated during action.

SUMMARY OF THE INVENTION

One feature of our invention resides in a novel construction of a fan assembly for a ventilator, comprising in combination a square ventilator housing having a first portion formed with a first passage of circular cross-section and wherein the fan assembly is at least partially received, and at least one second portion rigid with the first portion and formed with a second passage axially aligned and directly communicating with said first passage, said second passage having an open end spaced from the first passage and having throughout its length and at the open end thereof a cross-sectional area greater than the cross-sectional area of the circular first passage and a transverse dimension greater than the diameter of the circular first passage and electronic components as resistors, condensors, transistors, diodes and the like which are necessary for commutation and/or for electrical control of this fan assembly being placed inside one or more hollow portions in the corners of said square housing.

In a preferred embodiment of the invention said electronic components are mounted in hollow portions having their open ends on the inlet side of the fan assembly.

According to another feature of the invention the electronic components are mounted on such parts of the housing which have a direct metallic connection to a fan-cooled surface of said housing.

According to a still further feature of the invention the motor is carried by spoke-like supporting means and the electric cables connected to said electronic components are mounted in a recess of said spoke-like supporting means and there are plug connections between said cables and said motor.

The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The improved fan assembly itself, however, both as to its construction and its mode of operation, together with additional features and advantages thereof, will be best understood upon perusal of the following detailed description of certain specific embodiments with reference to the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional partial view taken along a radius from the center to one corner of a fan assembly according to the invention,

FIG. 2 is an elevated view of a smaller version in reduced scale taken from the input side of the fan assembly,

FIG. 3 is a circuit diagram of the electric motor and the associated electronic components mounted within the housing of said motor.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the embodiment illustrated in FIG. 1 a square housing 1 surrounds an electric motor 1'. Electronic components 2 such as resistors, condensors, transistors, diodes and the like which are necessary for commutation and/or for electrical control of this fan assembly, are mounted in hollow portions 3 which are in the region of corners of said housing. The propeller fan is of the type wherein the rotor surrounds the stator, the blades of the fan being affixed to the peripheral parts of said rotor. The rotating shaft of the rotor is turnably mounted in bearing means which are surrounded by a tubular housing (not shown) on which the laminae 4 and the plate 4' are mounted and which is affixed to the flange-shaped member 5.

Within the hollow portions 3 of the housing 1 there are ribs 6 on which a transistor 2' is affixed. These ribs have a direct metallic connection to the inclined fan-cooled surface 7 of said housing. As the particular construction of the housing 1 increases considerably the input of air as well as the output and decreases air friction said inclined surface 7 is perfectly cooled and the heat originating in transistor 2' is easily dissipated.

Spoke-like mounting means 10 are firmly connecting the corners of the housing with the stator flange 5 on which the motor is mounted. The spoke-like parts 10 are especially shaped as guiding means and protection for the electric cables 10' which connect transistor 2' and other electrical components with the motor. In one corner there are mounted plugs 11 which are connected with the electric circuit of the motor so that the fan assembly can easily be connected with the mains by means of these plugs.

In the circuit diagram of FIG. 3 there are illustrated by way of example the electrical connections between the motor and the associated electronic components mounted in the housing of the fan assembly. The four stator windings 13 and the hall semi-conductors 14 which are in the central part of the housing 1 are shown on the left. All other electronic components which are mounted in the corners of the housing are shown on the right. There are plug connections 15 so that the motor may easily be replaced by a new one.

The magnetic field of the motor will influence the hall semi-conductors so that their resistance is varying in well-known manner according to the actual position of the rotor. The transistors 16, 17, 18, 19 connected with said hall semi-conductors 14 will become conductive one after the other, the diodes 20, 21, 22, 23 will become conductive one after the other and accordingly a current will flow through the associated windings 13. By means of the potentiometer 24 the speed of the motor can be changed. For the purpose of electronic control of the speed the potential derived from the winding of the motor (which is acting as tacho-generator) is compared with a reference potential derived by means of the zener diode 25. The transistors 26 and the associated resistors have a per se known function in this device for controlling the speed of the motor.

When electronic or other equipment has to be ventilated, there is an increasing tendency to control the amount of air-flow through said equipment. This can be done easily be controlling the speed of the fan.

The present invention offers a novel and advantageous way for housing the electronic components, which are necessary for such control functions.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features which fairly constitute essential characteristics of the generic and specific aspects of our contribution to the art and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the claims.

Claims

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims:

1. A fan assembly for a ventilator, comprising, in combination, a square housing having hollow portions in the corners thereof and having a portion formed with a passage of circular cross-section and wherein a fan assembly is at least partially received, said fan assembly having a motor; spoke-like support means for carrying said motor and having longitudinal recesses; a plurality of electrical components including resistors, condensors, transistors and diodes comprising a control circuit for electrically controlling the fan assembly, said electrical components being placed inside at least one of the hollow portions in the corners of said square housing; electrical cables connected to said electrical components and mounted in a recess of said spoke-like supporting means; and plug connector means mounted on said housing and connecting said cables and arranged to be connected to a source of electrical energy.

2. A fan assembly for a ventilator according to claim 1, said electronic components being mounted in hollow portions having their open ends on the inlet side of the fan assembly.

3. A fan assembly for a ventilator according to claim 1, said electronic components being mounted with good thermal conductivity on such parts of the housing which have a direct metallic connection to a fan-cooled surface of said housing.