Modular OD/ID Grinding Machine with Bearings Preloaded by Inclined Iron Core Linear Electric Motor

摘要

A fundamentally precise and simple linear motion axis design is used as the basis for a modular two-axis 1D/OD grinding machine, where the attractive force from the linear motor is used to preload a carriage supported by six rigidly-attached porous carbon air bearings. The air bearings are assembled by vacuuming the pads to two orthogonal planes, positioning the carriage above the pads, and then injecting epoxy between the bearings and the carriage. Because the motor magnet attractive force is typically five times the axial force generated by the motor, the system is inherently stable even in the presence of large externally applied moments that might otherwise induce large pitch, yaw, or roll errors. In addition, a granite surface plate is used as the machine base, and it is supported on a steel frame with equal modulus, so that viscoelastic material between the two yields a critically damped system.