Fan motor bearing assembly

Claim 1

In a fan or like appliance of the kind comprising a stator mounted on a stationary support structure and concentric with a given axis, a fixed shaft mounted on the support structure in coaxial relation to the stator, a rotor positioned in coaxial relation to the stator, one encompassing the other, said rotor having a central bore encompassing said shaft, and a working load coupled in axial thrust-producing relation to the rotor, a bearing assembly for mounting the rotor on the shaft, comprising: a rotor bearing member mounted within said rotor bore and affixed to said rotor, said rotor bearing member having an axial opening larger than said shaft, through which said shaft projects, said rotor bearing member affording two oppositely facing rotor bearing surfaces each constitutinG a regular surface of rotation defined by rotation of an inclined line about said axis; a fixed stator bearing member, affixed to one end of said shaft and having a bearing surface engaging one of said rotor bearing surfaces; a floating stator bearing member, having an axial opening larger than said shaft, and having a bearing surface engaging the other rotor bearing surface; said bearing surfaces of said stator bearing members being complementary in configuration to the respective rotor bearing surfaces that they engage and at least one bearing surface of each mating pair comprising a self-lubricating surface; and resilient biasing means, extending between said support structure and said floating stator bearing member, for biasing said floating stator bearing member toward its associated rotor bearing surface in an axial direction corresponding to the direction of thrust from said working load to maintain both said stator bearing surfaces in engagement with said rotor bearing surfaces and thereby maintain said rotor and stator in accurate concentric alignment despite changes and imbalance in axial thrust, wear on the bearing surfaces, and thermal expansion; said biasing means being anchored to said support structure and to said floating stator bearing member to restrain said floating stator bearing against rotation.