| 摘要 |
A high torque motor drive, for rotating turntables, moving optical pickups in CD players, and other applications, employs two motors, drivingly connected in parallel. The outputs of motors used in compact machines are characterized by torque ripple curves in which torque peaks occur at predictable rotational phase angles of the motor's rotor. In the present invention, the rotors of the motors are interconnected by the drive train in such a way that the torque ripples cancel each other out. In a preferred embodiment of the invention, the torque ripple curve has torque peaks that occur every 60 degrees of angular displacement of the rotor. The rotors of the two motors are drivingly interconnected to maintain a one-to-one relationship between the rotor angular positions. The stators of the motors are positioned so that the torque peaks of one of the two motors occurs at a time different from those of the other motor. At least partial cancellation of the torque peaks is achieved. If only partial cancellation occurs, the result is that the drive cogs at a frequency that is twice that of a single motor. In addition, the stopping resolution for the drive of the invention is lower than in a system that employs one motor. Thus a CD player's optical pickup positioning resolution can be substantially increased. Smooth drive output is also achieved, which is a benefit for rotating a CD's turntable. Moreover, high torque is available in a compact unitary configuration. <MATH> |
