RU2659833C1 - Method and device for cooling rotor and electric motor of smoke exhauster - Google Patents

Abstract

FIELD: ventilation.

SUBSTANCE: invention relates to fan construction, in particular to fans for hot gases. Method for cooling the rotor and electric motor of the smoke exhauster, comprising co-axially securing the disc on a shaft connecting the motor and a high-temperature receiver of mechanical rotational energy, is characterized in that the disk is made in the form of a flat plate, the plane of which is perpendicular to the direction of the shaft, and a minimum of two holes are made in the disk. Device for cooling the rotor and electric motor of a smoke exhauster, comprising a disc coaxially fixed to a shaft connecting the motor and a high-temperature receiver of mechanical rotational energy, characterized in that the disk is made in the form of a flat plate and contains a minimum of two holes.

EFFECT: improving cooling efficiency, manufacturability and weight reduction.

5 cl, 4 dwg

Description

The invention relates to fan building, and in particular to fans for hot gases.

Known "HOT FAN WITH WATER COOLING" CN 2370324 [2], including the impeller 1, located below the fan 2 and the reflective cooling plate 11, the fan 2 and the reflecting plate 11 are combined into one node.

The disadvantage of this device is the low cooling efficiency due to the low coefficient of heat transfer from the heated shaft to the surrounding air.

The closest technical solution is the “FAN FOR HOT GASES” SU 1209938 [1], containing a round plate (disk) for mounting on a shaft connecting the engine and a high-temperature receiver of mechanical rotational energy.

The device has increased efficiency compared to [2] due to ring arches.

The disadvantage is the low cooling efficiency due to insufficient blowing of the disk with ambient air. The disadvantage is the low adaptability and increased weight of the device.

The technical result of the invention is to increase the cooling efficiency, manufacturability and weight reduction.

The technical result is achieved in that the method of cooling the rotor and the smoke exhauster motor, including coaxially securing the disk (of heat-conducting material) on the shaft connecting the motor and the high-temperature receiver of mechanical rotational energy, is characterized in that the disk is made in the form of a flat plate, the plane of which is perpendicular to the shaft direction , and at least two holes are made in the disk.

The cooling device of the rotor and the smoke exhaust motor containing a disk coaxially mounted on a shaft connecting the motor and a high-temperature mechanical rotational energy receiver is characterized in that the disk is made in the form of a flat plate and contains at least two holes.

The device may include an air guide snail to form a stream of heated air.

The number of round plates with holes can be more than two, and they are mounted on the shaft in parallel. The increase in the number of plates will increase the intensity of the shaft cooling.

The holes can be teardrop-shaped, located axisymmetrically. The specified implementation is high-tech and will avoid shaft imbalance.

The device is schematically shown in FIG. 1 (longitudinal section), FIG. 2 (cross section of the disk), FIG. 3 (general view), FIG. 4 (hole shape), where:

1 - engine;

2 - shaft;

3 - receiver of mechanical energy;

4 - disks;

5 - holes;

6 - node mounting the disk to the shaft;

7 - a snail.

The device operates as follows: the motor 1 rotates a shaft 2, on which a mechanical energy receiver 3 is mounted, for example, a fan blade for hot air, for example a smoke exhaust. Disks 4 are mounted on the shaft 2 by means of a collet fastening assembly 6, which is made of heat-conducting materials, such as copper or aluminum alloys. Holes 5 are made on the disks 4. Holes are required in an amount of at least two to maintain the balance of the disk. To organize the flow of air can be used snail 7.

When the motor shaft rotates, the collet mount of the discs, mounted on it, transfers heat from the shaft to the discs 4. Air flows through the holes 5 in the discs to cool them. Air is sucked in through the holes due to the action of centrifugal and friction forces that arise between the disks and the air, and moves from the shaft between the disks to their periphery, removes heat due to repeated contact of air molecules with the disks, heats up and is thrown out. Disks with holes begin to work like a fan, pumping air through themselves, from the shaft on the surface of the disks to the outside. In this case, the air moves very intensively from the center of the shaft to its periphery and more efficiently cools the disks with holes and the shaft of the exhaust fan motor, not only due to its larger amount, but also due to an increase in the area of contact of air with the disks. This does not happen in the absence of holes in the discs, as due to high temperatures, the mean free path of air molecules increases, which are heated by the shaft and disks, its density decreases and a zone of rarefaction of air arises between the disks at the shaft and the cooling rate of the shaft decreases. The air pressure at the shaft also arises due to the action of centrifugal forces on the air molecules, which try to throw them from the central part to the periphery of the disks, which prevents the flow of cold air to the shaft between the disks. In this case, cooling of the shaft and disks without holes is carried out only due to convection air flows moving from the shaft along the surface of the disks, and it is less efficient, because on the one hand, these convection flows from the disks side inhibit the oncoming cold central air stream directed to the engine shaft between the disks, and on the other hand, this cold stream also inhibits, as mentioned above, centrifugal forces, trying to push it out of the disks, which dramatically reduces the amount of cooling air entering the central, hottest part of the discs. For this reason, heat transfer without holes in the rotating discs is difficult and less efficient.

Heat removal with the help of rotating disks with holes directly depends on their area and their thickness (effective cross-section), which is necessary to ensure their thermal conductivity (to transfer the heat flux inside the disks from the center to the periphery) and their mechanical strength during rotation. When used as materials for disks, light and heat-conducting alloys, for example aluminum, lead to a decrease in their weight due to their manufacture from very thin plates (about 1.0 mm). The shape of the holes does not have to be round. The most effective is the shape of the “drop” holes depicted in FIG. 3. This shape of the holes allows you to maintain the optimal balance between the thickness of the disk, its mechanical strength, which ensures good heat transfer from the shaft to the disk, without reducing the heat flux density in the cross section of the disk near the shaft, where its diameter decreases and there is objectively little space for round holes , this requires pulling them into the drop, orienting it with the tip to the center of the shaft.

EFFECT: increased cooling efficiency is achieved by increasing the intensity of contact of air with a disk with holes. EFFECT: increase of manufacturability is achieved by simplification of manufacturing - it is enough to make a few in the plate. EFFECT: weight reduction is achieved by the possibility of manufacturing from a sufficiently thin plate with satisfactory cooling.

Industrial application. The invention can be successfully applied for the production and operation of engine shaft coolers for driving with high-temperature mechanical load, for example a smoke exhaust rotor.

Claims (5)

1. A method of cooling the rotor and the smoke exhaust motor, including coaxially securing the disk to a shaft connecting the engine and a high-temperature mechanical rotational energy receiver, characterized in that the disk is made in the form of a flat plate, the plane of which is perpendicular to the shaft direction, and at least two holes are made in the disk. 2. The cooling device of the rotor and the smoke exhaust motor containing a disk coaxially mounted on a shaft connecting the motor and a high-temperature receiver of mechanical rotational energy, characterized in that the disk is made in the form of a flat plate and contains at least two holes. 3. The device according to p. 2, characterized in that it contains an air guide snail. 4. The device according to p. 2, characterized in that the number of round plates with holes can be more than two, and they are mounted on the shaft in parallel. 5. The device according to p. 2, characterized in that the holes are made in a drop-shaped form, are located axisymmetrically.

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