AUSTRALIA Patents Act COMPLETE SPECIFICATION (ORIGINAL) Class Int. Class Application Number: Lodged: Complete Specification Lodged: Accepted: Published: Priority Related Art: Name of Applicant: Aktiebolaget SKF Actual Inventor(s): Bernt Wikgren, Kjell Widlund, Mans Isacsson, Stellan Tuvesson Address for Service and Correspondence: PHILLIPS ORMONDE & FITZPATRICK Patent and Trade Mark Attorneys 367 Collins Street Melbourne 3000 AUSTRALIA Invention Title: A BEARING ASSEMBLY AND A TRAVELING GRATE EQUIPPED WITH SUCH BEARING ASSEMBLIES Our Ref: 798951 POF Code: 13790/1650 The following statement is a full description of this invention, including the best method of performing it known to applicant(s): -1- 2 The low rotational speeds used (2 to 3 rpm) also will give a difficult situation from a lubrication point of view, due to the bad lubricant film ratio. These problems mean that the earlier used bearing assemblies in this first zone will 5 have a mean service life so low as of about 4000 hours, whereas the mean service life of the bearings in the other zones are about 14000 hours, i.e. about three and a half times the life of the first zone bearings. It would be desirable to provide a bearing assembly with rolling bearing, 10 accommodating and misalignments and also axial shaft elongation without the drawbacks and difficulties of the earlier used solutions. According to the present invention, there is provided bearing assembly incorporating a bearing housing in which is provided at least one rolling bearing, a shaft sleeve for 15 mounting the assembly on a shaft journal, and sealing means sealing off the space between the bearing housing and the shaft sleeve, whereby the bearing assembly further incorporates a base plate, arranged to support the bearing housing in a manner allowing axial displacements and misalignments of the shaft journal to take place outside the bearing housing, wherein the bearing housing is equipped with slide ?0 members arranged to slide on at least one wear rail forming part of the base plate, and thereby being adapted to compensate said axial displacements and misalignment outside the bearing housing. The invention also relates to a traveling grate of the type specified, which is equipped 25 with such bearing assemblies. Hereinafter the invention will be further described with reference to a non-limiting embodiment, illustrated in the accompanying drawings. 30 Fig. 1 illustrates in a schematic view from above a portion of a traveling grate, Fig. 2 is a perspective view of a bearing assembly according to the invention, C:\pof\wordSPEC-79895I.doc 2A Fig. 3 is a cross section of the bearing assembly according to Fig. 2, shown along line B-B in Fig. 4, and Fig. 4 is longitudinal section of the bearing assembly according to Figs. 2 and 3, 5 shown along line A-A in Fig. 3. Fig. 1 illustrates schematically from above a portion of a grate belt 1, in the illustration having three rows of grate plates 2 and link plates 3, interconnecting the adjacent grate plates in each row, and allowing them to bend in relation to the adjacent grate o plates for C \poftord\SPEC-798951.doc 3 following the curvature of driving shaft and the reversing shaft (not shown). Between these driving and reversing shafts the grate plates are supported on continuous upper supporting shafts 4, which are supported in rolling bearings positioned in bearing assemblies 5, positioned on the outside of the oven wall 6. Although the illustration shows three rows of 5 grate plates 2 having three plates in each group, and four series of link plates 3, the grate belt normally has in each row fifteen grate plates, which are linked to each other by means of six link plates. The temperature on the surface of the bearings can be estimated to between 60 and 80 "C, whereas the temperature of the environment nearest to the bearings can be about 120 *C. The travel direction of the traveling grate is shown by the arrow A. 10 Fig. 2 shows in perspective a bearing assembly 5, comprising a bearing housing 7, which is resting in a substantially cradle-formed base plate 8, and in which is supported one end of a supporting shaft 4. The bearing housing 7 and the base plate 8 with bearings, seals and a shaft sleeve as a unit to the place where it shall be used, and there it is arrested to a stand 9. 15 As can be better seen in Fig. 4, which shows the bearing assembly 5 according to Fig. 2 in cross section, the end of the shaft 4 forms a shaft journal 4a of smaller diameter. In this embodiment, the shaft journal 4a is inserted in a shaft sleeve 10, preferably a SKF ConCentra SHL bushing, which has a low mounting height and which gives a fully 20 concentric locking. This shaft sleeve 10 is part of the bearing assembly unit 5 and the bearing assembly therefore can be easily pushed up on the shaft journal 4. On the shaft sleeve 10 there is, in this preferred embodiment, arranged two double row spherical roller bearings 1 Ia, I I b, which are equipped with integrated high temperature seals, and which are positioned in the bearing housing 7. The bearings I I a, I I b can be mounted either as 25 locating or non-locating bearings. Outside the bearings, there is on each side provided in the bearing housing 7 an outer seal 12, preferably in form of labyrinth seals with flocked washers. The bearings I la, 1 lb and the bearing assembly unit 5 are completely filled with a proper high temperature grease when the bearing assembly is delivered from the manufacturing site. 30 The inner bearing I I b is mounted abutting a shoulder in the bearing housing 7, and between the inner bearing 1 I b and the outer bearing I Ia is provided a guide ring 13, 4 keeping the two bearings spaced apart. The outer bearing 1 la is secured in position by means of a cover 14, which is affixed by means of bolts. For permitting axial displacements caused e.g. by thermal elongation of the long shaft and 5 also motions caused by misalignments due to deflections and the like, the bearing housing 7 is supported in the base plate 8 via wear plates 15, 16 and wear rails 17, as can be seen in Figs. 2 and 3. A plate 18 with a recess for one of the wear plates 15 is attached outside the wear rail 17 in such a manner that there is a small slit s between the plate 18 and the adjacent part of the bearing housing 7. 10 The cradle-formed base plate 8 has a center portion with a curved recess and raised side portions to which said wear rail 17 is/are fitted, whereas the bearing housing 7 has a substantially cylindrical main portion in which the at least one rolling bearing I la, I lb is arranged, and two flange portions projecting in opposite directions from the main portion, 15 said slide members 15, 16 being fitted to the bearing housing 7 in positions coinciding with the wear rail 17 Due to this arrangement it is not needed that shaft expansions and misalignments are taken up in the bearings, and it is therefore possible to use the illustrated and described bearing 20 assembly, wherein the bearing housing 7 with bearings I Ia, I I b, shaft sleeve 10, guide ring 13 and integrated seals can be provided as a closed unit, which has a sufficient internal volume of lubricant, and which is delivered together with the base plate 8 and wear plates 15, 16 and wear rail 17. 25 Any motions for which the bearing housing is subjected during operation are taken up as sliding motions between wear plates 15, 16 and wear rail 17, and the self-contained bearing housing unit 5 therefore can be easily handled and mounted also by personnel having no especial knowledge of mounting of bearings. 30 The use of the self-contained bearing assembly with the shaft sleeve 10 permits a very simple mounting and dismounting on a shaft journal. The sealing arrangements integrated in the bearings and also in the bearing housing gives a prolonged service life compared to 5 conventional designs, and this results in a substantial reduction of the lubrication grease needed. The invention is not limited to the bearing assembly as illustrated in the accompanying 5 drawings and described with reference thereto but modifications and variants are possible within the scope of the attached claims. Although described in connection with a traveling grate, the bearing assembly as claimed, is not at all limited to such a use, but it is also useful in other applications where similar 10 demands are at hand.