Substrate treating apparatus and rotating assembly

An apparatus for treating a substrate, the apparatus comprising:

• a support unit including a support plate configured to support the substrate and a rotary drive member configured to rotate the support plate;
• and
• a lower fluid dispensing unit configured to dispense a fluid onto a lower surface of the substrate supported on the support plate,
• wherein the rotary drive member includes:
• a hollow shaft coupled with the support plate;
• and
• an actuator configured to rotate the hollow shaft,
• wherein the lower fluid dispensing unit includes:
• a fixed shaft having an interior space and provided in the hollow shaft;
• and
• a fluid dispensing tube configured to dispense the fluid and provided in the interior space, and
• wherein an air-flow generation part is formed on an inner surface of the hollow shaft to generate a downward air flow in a space between the hollow shaft and the fixed shaft when the hollow shaft rotates.

A rotating assembly comprising:

• a body;
• a hollow shaft coupled to the body to rotate the body;
• and
• an insert provided in the hollow shaft and located to be spaced apart from the hollow shaft, the insert being fixed in position when the hollow shaft rotates,
• wherein an air-flow generation part is formed on an outer surface of the insert to generate a downward air flow in a space between the hollow shaft and the insert when the hollow shaft rotates.

A rotating assembly comprising:

• a body;
• a hollow shaft coupled to the body to rotate the body;
• and
• an insert provided in the hollow shaft and located to be spaced apart from the hollow shaft, the insert being fixed in position when the hollow shaft rotates,
• wherein an air-flow generation part is formed on an inner surface of the hollow shaft to generate a downward air flow in a space between the hollow shaft and the insert when the hollow shaft rotates, and
• wherein the air-flow generation part has a helical shape.