Processing apparatus

A processing apparatus comprising:

• a processing unit configured to process a workpiece;
• a control unit configured to control the processing unit;
• and
• a temperature detecting unit;
• the processing unit including:
• a processing tool configured to process the workpiece, and
• a spindle assembly including a spindle having the processing tool mounted on a distal end of the spindle and a spindle housing through which the spindle is inserted, the spindle housing having an air bearing configured to support the spindle by air,
• a cooling fluid passage being formed in the spindle housing, the cooling fluid passage surrounding the air bearing and cooling the spindle assembly, the cooling fluid passage having one end connected to a cooling fluid supply source and having another end communicating with a cooling fluid outlet of the spindle housing,
• the temperature detecting unit detecting a temperature of the spindle housing,
• the control unit determining whether a state of cooling of the spindle assembly is normal or abnormal on a basis of the temperature detected by the temperature detecting unit,
• wherein the control unit determines that the state of cooling of the spindle assembly is abnormal when the temperature of the spindle housing being detected by the temperature detecting unit is equal to or higher than a first predetermined value;
• and wherein the control unit determines that the state of cooling of the spindle assembly is abnormal when the temperature of the spindle housing being detected by the temperature detecting unit is equal to or lower than a second predetermined value, the second predetermined value being lower than the first predetermined value;
• and wherein the control unit determines that the state of cooling of the spindle assembly is abnormal when a change in the temperature of the spindle housing being detected by the temperature detecting unit in a fixed time is equal to or more than a third predetermined value the third predetermined value being a predetermined value of the change in temperature of the spindle housing in the fixed time;
• and
• the control unit temporarily stopping operation of the processing unit in response to a determination that the state of cooling of the spindle assembly is abnormal, and the control unit continuing operation of the processing unit in response to a determination that the state of cooling of the spindle assembly is not abnormal.