Externally pressurized gas bearing spindle assembly
AssigneeNtn Corporation
InventorsYoshio Fujikawa, Takayuki Itoh
Life of this patent
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Abstract
A compact externally pressurized gas bearing spindle assembly can increase the degree of vacuum in a vacuum chamber. In a spindle assembly wherein a rotary shaft is provided in a housing through a bearing gap, and compressed gas is introduced into the bearing gap to support the rotary shaft in a non-contact manner relative to the housing, an exhaust gas suction device for sucking gas discharged from the bearing gap is provided inside the housing or the rotary shaft. The bearing gap near the outside of the housing is smaller than the other bearing gap. Near the bearing gap near the outside of the housing, a non-contact seal gap is formed to prevent leakage of compressed gas into the vacuum chamber in a non-contact manner.
Claims12
A spindle assembly comprising a housing, and a rotary shaft rotatably mounted in said housing through a bearing gap, wherein two externally pressurized gas bearings for supporting said rotary shaft at least in an axial direction through a bearing gap in a non-contact manner are provided in said housing, wherein said two externally pressurized gas bearings respectively have bearing gaps, wherein said bearing gaps include a first bearing gap and a second bearing gap, said first bearing gap being nearer to the outside of said housing than said second bearing gap and being smaller than said second bearing gap, and wherein a non-contact seal gap is formed near the externally pressurized gas bearing nearer to the outside of said housing to prevent exhaust gas from said externally pressurized gas bearings from leaking to the outside of said housing.
Dependencies are inferred from the claim text.