ANCA Receives Patent for Motor Temperature Control Technique

ANCA CNC Machines has been granted a U.S. patent for motor temperature control (MTC), a technique that is said to improve the stability of precision machine tools.

ANCA’s patent is a way of maintaining motorized spindles at a constant temperature. According to the company, a significant problem in the use of precision machine tools is the impact of changes in temperature, particularly in the temperature of the spindle. Changes in temperature of the machine tool can be caused by changes in ambient temperature, coolant temperature, run time, spindle rpm and spindle load. ANCA’s solution is to actively control spindle temperature by varying the electrical losses in the motor element while simultaneously maintaining spindle motor speed and load. This is accomplished by using special firmware in the spindle drive amplifier.

A common approach to precision machining is to run the machine in a warmup cycle to bring all the elements of the machine to some level of thermal stability. Typically, this warmup cycle will take approximately half an hour. Using MTC, this time can reportedly be reduced to around five minutes.

ANCA manufactures a special machine, the GCX, for grinding skiving cutters used to manufacture internal and external gears of electric vehicles. Electric vehicles incorporate a high-speed gear box in their drivetrain. The accuracy of the components of this gear box will impact the lifetime, efficiency and noise of the electric vehicles. MTC is a key enabling technology for the GCX to produce cutters to AAA class. It is used to control the temperature of a dressing spindle which is used to create a high accuracy profile on the grinding wheel. MTC is also being used to control the main grinding spindle temperature during up to 12 hours of continuous grinding.