A new mechanism for boring of non-circular hole and its control method

For boring of non-circular hole the boring bar must be applied with a contactless force to take a micro displacement radially. A compound deformable body is built and connected to the machine spindle. One end of the compound deformable body is a flexure-hinged elastic body and the other is a electromagnetic rotor, around the rotor is a 8-poles stator with eight actuation coils. The electromagnetic force between the rotor and stator can be changed by changing the currents in the coils. With the linearization of the magnetic force near the quiescent operating point, the linear relationship between the magnetic force and control current can be established, and the synchronizing control method of the electromagnetic force can be acquired. Theoretical analysis show that the rotor can get a ideal micro displacement when the actuation currents satisfy certain amplitude and phase angle conditions. Simulation tests indicate that a magnetic force rotating with the rotor synchronously can be generated, and the micro displacement between the rotor and stator is almost proportional to the control current. It is feasible for the proposed mechanism to supply a controllable micro displacement to the boring bar.