GB1586497A - Shaft cooling - Google Patents

Abstract

One end (9) of the shaft of the electric motor (1) projects through a front panel (11) into a hot environment (19). In order to minimise the transfer of heat through the shaft and the front panel (11), a bucket wheel (15) rotating with the shaft, which exposes axial openings (17), and a stationary, radially aligned guide plate (10) are provided which generate a cool air current axially against the shaft end (9) and radially along the front panel (11). The aforementioned shaft end (9) can be used as a shaft in a galette bearing housing. <IMAGE>

Description

(54) SHAFT COOLING (71) We, HEEMAF B.V., a company organized under the laws of The Netherlands, of 5 Bornsestraat, Hengelo, The Netherlands, do hereby declare the invention, for which we pray that a Patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The invention relates to apparatus for use adjacent to a source of heat. including a stationary front plate having a front face for facing the source, and a rotary shaft passing through the front plate so that a first portion of the shaft is then heated bv the source.

Particularly in driving a heated roller in the textile industry. high temperatures of, for example. 250"C, are involved. Heat is transferred through the driving shaft and the front plate to a second portion of the shaft which extends from a rear face of the front plate. Especially the bearing located nearest the front plate is thus exposed to potential damage.

Hitherto this bearing has been cooled with the aid of an oil fog. However. in practice this gives rise to environmental drawbacks. since the oil fog is found to leave the housing and enters the factory hall.

The invention has for its object to provide means such that the transfer of heat to the bearing is reduced. This is achieved by arranging that the first and second shaft portions are supported solelv by bearings which. considered from the front plate. are beyond the second shaft portion. the appar atus also including means for directing a cooling air stream in an axial direction in contact with the second shaft portion to wards the rear face of the front plate and then radially outwards from the second shaft portion in contact with the reir face of the front plate. Since the cooling air flow along the shaft passes in countercurrent to the heat transport. the cooling effcct of the air is at the optimum.

Said means may be formed by a blade wheel rotating together with the second shaft portion and leaving axial openings and by a stationary radially extending guide plate. The guide plate guides the cooling air stream inwards in a radial direction. The rotating blade wheel deflects the radial air stream along the shaft and then in a radial direction outwards.

The blade wheel is preferably made from thermally conductive material. This has the advantage that the blade wheel can condudt heat away in a radial direction from the shaft.

The invention will be described more fully with reference to the accompanying drawings.

In the drawings Figures I and 2 are longitudinal sectional views of two apparatus according to the invention.

The electric motor I shown in Figure 1 comprises a housing 2 provided with axially extending cooling vanes 3. Inside the housing 2 are arranged the stator windings 4. A rotor is rotatably arranged in the housing 2 with the aid of bearings 5 and 6. The shaft 9 has its right-hand end located in surroundings 19. e.g. a roller. including a source of heat and having a high temperature. for example. of 25() C. Owing to the heat transfer through the shaft 9. inter alia the bearing 6 might be damaged.

A radial guide plate 10 is mounted between a bearing shield 18 and a front plate 11. On either side of the guide plate 1() there are provided inlet and outlet ports 13 and 14 respectively. At a radial distance from the shaft 9 a blade wheel 15 is arranged in concentric position. Passages 17 are left free between the hub 16 of the blade wheel 15 and the shaft 9. The air stream produced by the blade wheel moves radially inwardly.

then axially along in contact with the shaft and finallv radially to the outside. The air stream is indicated by arrows. Apart from cooling the shaft 9, the air stream also cools the bearing shield 18, whilst the radially emerging air, in addition, cools the front plate 11. The guide plate 10 is cooled by the incoming as well as by the outgoing air stream. The blade wheel 15 is made from thermally conductive material so that by conduction it can transfer heat from the shaft 9 in radial direction to the outside.

Figure 2 shows an arrangement in which a motor, with the exception of a blower 8 cooling the housing, on the shaft end 7, corresponds with that shown in Figure 1.

The corresponding parts are designated by the same reference numerals. The motor shaft is coupled through a coupling means 20 with a shaft 9, the right-hand end of which is located in surroundings adjacent to a source of heat having a high temperature.

This may apply to a heated roller 19 in the textile industry, with a heating unit 23. With a view to a critical speed, larger rollers may require a shaft 9 having a larger diameter.

This shaft 9 is journalled with the aid of bearings 21 and 22 which might be damaged by the high temperature. As in Figure 1, the shaft 9 is cooled by an air stream produced by a blade wheel 15 and guide plate 10. Thus the bearings 21 and 22 are protected from an excessively high temperature.

WHAT WE CLAIM IS: 1. Apparatus for use adjacent to a source of heat. including a stationary front plate having a front face for facing the source, and a rotary shaft passing through the front plate so that a first portion of the shaft is then heated by the source. while a second portion of the shaft extends from a rear face of the front plate. the first and second shaft portions being supported solely by bearings which. considered from the front plate. are beyond the second shaft portion. the apparatus ilso including means for directing a cooling air stcam in an axial direction in contact with the second shaft portion towards the rear face of the front plate and then radially outwards from the second shaft portion in contact with the rear face of the front plate.

2. Apparatus Iccoldil1y to claim 1. characterised in that said means are formed bv a blade wheel rotating together with ihe second shaft portion and leaving free axial openings and by a stationary radially directed guide plate.

3. Apparatus according to claim 2. char- acterised in that the hlade wheel is made from thermally conductive material.

4. Apparatus according to iny of clams 1 to 3. characterised in that said second shaft portion is part of the shaft of in electric motor.

5. Apparatus according to any of claims I to 3. characterised in thnt the first shift portion carries a roller. oncl the second shaft portion extends into a bearing housing.

6. Apparatus according to claim 1, substantially as described and illustrated by Figure 1 or Figure 2 of the accompanying drawing.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (6)

**WARNING** start of CLMS field may overlap end of DESC **. cooling the shaft 9, the air stream also cools the bearing shield 18, whilst the radially emerging air, in addition, cools the front plate 11. The guide plate 10 is cooled by the incoming as well as by the outgoing air stream. The blade wheel 15 is made from thermally conductive material so that by conduction it can transfer heat from the shaft 9 in radial direction to the outside. Figure 2 shows an arrangement in which a motor, with the exception of a blower 8 cooling the housing, on the shaft end 7, corresponds with that shown in Figure 1. The corresponding parts are designated by the same reference numerals. The motor shaft is coupled through a coupling means 20 with a shaft 9, the right-hand end of which is located in surroundings adjacent to a source of heat having a high temperature. This may apply to a heated roller 19 in the textile industry, with a heating unit 23. With a view to a critical speed, larger rollers may require a shaft 9 having a larger diameter. This shaft 9 is journalled with the aid of bearings 21 and 22 which might be damaged by the high temperature. As in Figure 1, the shaft 9 is cooled by an air stream produced by a blade wheel 15 and guide plate 10. Thus the bearings 21 and 22 are protected from an excessively high temperature. WHAT WE CLAIM IS:

1. Apparatus for use adjacent to a source of heat. including a stationary front plate having a front face for facing the source, and a rotary shaft passing through the front plate so that a first portion of the shaft is then heated by the source. while a second portion of the shaft extends from a rear face of the front plate. the first and second shaft portions being supported solely by bearings which. considered from the front plate. are beyond the second shaft portion. the apparatus ilso including means for directing a cooling air stcam in an axial direction in contact with the second shaft portion towards the rear face of the front plate and then radially outwards from the second shaft portion in contact with the rear face of the front plate.

2. Apparatus Iccoldil1y to claim 1. characterised in that said means are formed bv a blade wheel rotating together with ihe second shaft portion and leaving free axial openings and by a stationary radially directed guide plate.

3. Apparatus according to claim 2. char- acterised in that the hlade wheel is made from thermally conductive material.

4. Apparatus according to iny of clams 1 to 3. characterised in that said second shaft portion is part of the shaft of in electric motor.

5. Apparatus according to any of claims I to 3. characterised in thnt the first shift portion carries a roller. oncl the second shaft portion extends into a bearing housing.

6. Apparatus according to claim 1, substantially as described and illustrated by Figure 1 or Figure 2 of the accompanying drawing.