Rotary table device

A rotary table device comprising:

• a rotary table;
• a case supporting the rotary table rotatably around a rotation axis;
• a center shaft erected toward the rotary table in a position of the case corresponding to the rotation axis;
• a housing fixed to the case and spaced apart from the center shaft to surround the center shaft, the housing including an inner peripheral surface having a circular cross section over a predetermined range along the rotation axis;
• a center sleeve disposed outside the center shaft and inside the housing, the center sleeve being fixed to the rotary table, the center sleeve including an outer peripheral surface having a circular cross section corresponding to the inner peripheral surface, and the outer peripheral surface being configured to rotate concentrically with the inner peripheral surface;
• a rotary encoder disposed on the center shaft and the rotary table, the rotary encoder being configured to detect a rotation angle of the rotary table;
• a plurality of recesses formed in at least one of the inner peripheral surface and the outer peripheral surface to form a flow path of a fluid;
• a plurality of O-rings disposed to be sandwiched between the inner peripheral surface and the outer peripheral surface to prevent a leakage of the fluid from the plurality of recesses;
• an in-housing fluid flow path formed inside the housing and each communicating with the plurality of recesses;
• a plurality of in-sleeve fluid flow paths formed inside the center sleeve and each communicating with the plurality of recesses to supply the fluid into the flow path provided in the rotary table;
• and
• a gap is formed between an outer surface of the center shaft and an inner surface of the center sleeve along an entire length of the center sleeve.