Patent ID: 6149418
Filing Date: 2000-11-21
Classification: B29C

Abstract:
An injection molding machine having a drive system comprising:a. first and second electric motors each having a housing and an output shaft extending axially from a drive end of the housing, wherein the motors are oriented in spaced relationship with each other and have their respective drive ends in opposed relationship with the axes of their respective output shafts disposed coaxially;b. a motor coupling member extending between and coupling together the output shafts of the first and second motors so that the motor output shafts rotate together in the same direction of rotation and at the same rotational speed;c. a motor control for controlling the speed and torque of the first and second motors, the motor control including a first motor drive circuit coupled with the first motor for operating the first motor output shaft to rotate in a predetermined direction of rotation, and a second motor drive circuit coupled with the second motor for operating the second motor output shaft to rotate in the same predetermined direction of rotation as that of the first motor output shaft, to provide at the motor coupling member a combined output torque that is the sum of the output torques of the first and second motors, wherein the second motor drive circuit includes an inverter for shifting the phase of drive current supplied to the second motor relative to the phase of drive current supplied to the first motor.