Thrust bearing device

DETAILED DESCRIPTION In view of the above-described problems of the prior art, it is an object of the present invention to provide a thrust bearing device for an electric motor which is designed so that components, particularly those on the stationary side, are unified so as to achieve a marked reduction in the production cost without adversely affecting the performance heretofore achieved in the prior art.
In order to solve the problems stated above, the present invention provides a thrust bearing device for an electric motor lubricated by liquid within a motor casing which comprises a rotary disk directly or indirectly fixed on a primary shaft of the motor and a sliding shoe member having sliding surfaces slidably in contact with a sliding surface of the rotary disk.
The sliding shoe member is made of metal and is provided with a plurality of segmented shoes unitarily connected to a common base through respective ribs.
The sliding shoe member is fixed to a motor bracket with a gap having a predetermined configuration provided between the retaining surface of the motor bracket and the bottom surface of the common base of the sliding shoe member at each of the portions thereof which respectively correspond to the shoes.
By virtue of the above-described arrangement, when a load is applied to the thrust bearing device, the shoes are deformed elastically and a liquid film having a wedge shape is formed between the rotary disk and the shoes.
Hence, a high load bearing capacity can be expected of this device, as in the case of a conventional thrust bearing device employing a tilting pad system.
At the same time, the gap that is present between the common base of the sliding shoe member and the motor bracket absorbs the deflection caused by the inevitable manufacturing tolerances on the sliding surface of the disk and the top surface of the bracket, thereby preventing local contact of the sliding surfaces of the shoes of the sliding shoe member, and thus enabling the sliding mode of the shoes to be kept uniform