Patent ID: 7458728

Claim:
A rotary apparatus comprising: a non-rotary part, a rotary shaft rotatable relative to the non-rotary part, a rotary member provided between the rotary shaft and the non-rotary part, an inside bearing provided between the rotary shaft and the rotary member, and an outside bearing provided between the rotary member and the non-rotary part, wherein the inside bearing comprises a first inside bearing and a second inside bearing which are spaced to each other along a direction of a central axis of the rotary shaft, wherein the outside bearing comprises a first outside bearing and a second outside bearing, which are, spaced each other along the direction of the central axis of the rotary shaft, wherein an outer ring of the first inside bearing and an inner ring of the first outside bearing are fixed on the rotary member, wherein an outer ring of the second inside bearing and an inner ring of the second outside bearing are fixed on the rotary member, wherein an inner ring of the first inside bearing and an inner ring of the second inside bearing are fixed on the rotary shaft, wherein an outer ring of the first outside bearing and an outer ring of the second outside bearing are fixed on the non-rotary part, wherein the first inside bearing, the first outside bearing, the second inside bearing, and the second outside bearing are interlocked such that the outer ring of the first outside bearing and the outer ring of the second outside bearing move along the direction of the central axis of the rotary shaft, and the rotary member slightly moves along the direction of the central axis, such that at least two of the first inside bearing, the first outside bearing, the second inside bearing, and the second outside bearing receive preloads, respectively, with a linkage relationship.