US2391670A - Heat dissipating system for bearings - Google Patents

Description

Dec. 25, 1945. T. J. BAY ETAL HEAT DISSIPATING SYSTEM FOR BEARINGS Filed May 18, 1942 mamas JBcz Mornfs g A TT INVENTOR.

atented ii Thomas 3. Bay and Morris R. Machol, Washington, D. 0.

Application May 18, 1942, Serial No. 443,484

4 @laims.

This invention relates to bearings and it has a particular relation to cooling means therefor.

In most bearings there is a space or air gap, small though it may be, between the babbitt metal and the metal of the bearing housing which presents an eflective barrier to the transfer of heat from the former to the latter. This impediment to the passage of heat is particularly noticeable in railway car bearings in which even though the babbitt metal is cast in a bronze backing member an air gap exists between this member and the steel bearing wedge and also between the wedge and the housing or journal box. Inasmuch as a large proportion of the heat generated by friction between the journal and the bearing and between the journal and the waste must be dissipated by this route over-heating and hot boxes are a frequent occurrence.

The principal object of the present invention is toassist in the transfer of heat from a bearing by short circuiting the air gaps above described by means of one or more conductors of relatively high thermal conductivity thermally bonded at one end to the babbitt metal of the hearing or to the backing member if the babbitt is cast therein and also thermally bonded at its other end to the housing or other metallic member located remote thereto and capable of readily dissipating heat transferred thereto. This member may, in the case of railway car bearings, be a portion of the journal box located in the air stream, or in an electric motor,. this member may be the motor casing. In certain other installations the heat may b transferred through such a conductor to a portion of a ship or building located a. considerable distance from the bearing and having the necessary heat dissipating characteristics.

With these and other objects in view, as well as other advantages that may be incident to the use of the improvements, th invention consists in the parts and combinations thereof hereinafter set forth and claimed, with the understanding that the several necessary elements constituting the same may be varied in proportion and arrangement without departing from the nature and scope of the invention, as defined in the appended claims.

In order to make the invention more clearly understood, there ar shown in the accompanying drawing means for carrying the invention into practical use, without limiting the improvements in their useful application to the particular construction, which, for the purpose of explanation, have been made the subject of illustration.

In the accompanying drawing:

Fig. 1 is a perspective view of a railway car bearing showing a heat conductor connected at one end with the bearing back and at its other end with the Journal box at a point located in the air flow;

Fig, 2 is a fragmentary transverse sectional view on a larger scale showing the heat conductor thermally bonded at its inner end to the babbitt metal;

Fig. 3 is a similar view showing the inner. end of th heat conductor thermally bonded to the bearing back;

Fig. e is an enlarged fragmentary sectional view showing one method of thermally bonding the outer end of the heat conductor to the bear ing housing or other heat dissipating or absorbing element; and

Fig. 5 is a view partly in elevation and partly in section of a bearing of conventional type wherein the inner end of the heat conductor is embedded in the babbitt metal and its other end thermally bonded to a. heat absorbing or dissipat ing element located remote to the bearing.

Referring to the drawing, and particularly to Fig. 1 thereof, a railway carbearing is shown as comprising a bearing housing or journal box it equipped with the usual dust plate 5 i which surrounds the axle or shaft 52 adjacent to the axle journal I3 and which functions as a heat dissipating 'means. Supported by the journal 53 is a backing member M of bronze or bronze alloy to the inner faceof which a shaft-engaging bushing of babbitt i5 is thermally united by casting. This member is held in position by a steel wedge lfiwhich bears directly upon the journal box it. It will be noted from an inspection of Figs. 2 and 3 that there is an air gap ll between the backing member l4 and the wedge l6 and also an air gap 58 between the wedge'and the journal box it. In some instances there may also be an air gap l9 between the babbitt metal I5 and the backing member l4. These air gaps, small as they are,

present a serious barrier to the transfer of heat to the journal box for dissipation thereby.

According to the present invention, this diiiiculty is overcome by short circuiting or by-passing the air gap or gaps by means of a member 20 having a high coefilcient of thermal conductivity and herein shown as consisting of a stranded wire cable of copperor other suitable metal.

As illustrated in Fig. 2, the conductor 20 passes through an opening 2| drilled in the backing member 54 and its inner end is frayed and embedded in the 'babbitt metal iii to provide a thermal bond therewith. In forming this type ing surface of the babbitt so as to allow for con-' siderable wear before exposing or contacting the strands of the conductor. The outer end of the conductor 20 extends into an aperture 23 drilled in the Journal box it, part of which is located in the air stream and is thermally bonded therein by soldering, brazing or welding, as indicated at 24, In forming this connection the surface of the aperture 23 and the end of the conductor are tinned or otherwise suitably prepared, and the end of the conductor inserted in the aperture. The strands of the conductor are then spread into intimate contact with the wall of the aperture by a center punch or drift pin and a wedge 25 of solder then driven in the opening thus formed, as shown in Fig. 4. The conductor and surrounding area of the journal box is then heated in any suitable'manner, such as by a blow torch,-until the solder is melted and forms I a thorough bond between the strands of the cable and the wall of the journal box.

In some installations it may be found to be more convenient and practical, particularl in replacement'jobs, to thermally bond the inner end of the conductor 20 in a socket 26 drilled in the backing member I, as shown in Fig. 3.

In Fig. there is illustrated diagrammatically a conventional bearing in which a babbitt liner 28 is cast into dovetailed slots 29. In this form of the invention a stranded conductor 30 passes through an opening iii in the bearing cap 32 and its inner end frayed and the several strands thereof tinned and bent into one of the adjacent slots after which the babbitt metal is cast in position so as to embed the strands of the conductor therein. Also, in this figure the conductor is shown as being thermally bonded, as at 33, to a heat dissipating metallic means or either initially or when it may become necessary to reline the hearing, or at any intermediate time.

It will be understood that the above description and accompanying drawing comprehend only the general and preferred embodiment of the invention and that various changes in construction, proportion and arrangement of the parts may be made within the scope of the appended claims without sacrificing any of the advantages of the invention.

The invention described herein may be manufactured and used by or 'for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

What is claimed is:

l. A bearing structure including a backing member, a bushing member thermally united with said backing member for frictional contact with a shaft, heat dissipating means spaced from for frictional contact with a shaft, and means members.

element 34 located at a point spacedfrom the bearing. This element may be the casing of an electric motor, the wall or roof of a. buildin or the hull or bulkhead of a ship according to the nature of the installation. Also, in some instances, the outer end of the conductor 30 may be secured to a separate water cooled device or it may be immersed in a cooling element.

From the foregoing ,it will be appreciated that a very effective means is provided for augmenting the cooling of a bearing and one that may beincorporated at little expense in a bearing 3.- A bearing structure including a bearing housing, a backing member in said housing and having an air gap therebetween, a bushing member thermally united with said backing member for frictional contact with a shaft, and a flexible cable having a relatively high coeflicient of thermal conductivity arranged to bridge said air gap thermally bonded at one end to said housing and at its other end to said bushing member.

4. A bearing structure including a bearing housing, a backing member insaid housing and

Images