Method for braking a loom

摘要

A driving apparatus (30, 50) for a loom (10) includes a main shaft (14) that transmits a rotational force to devices included in the loom (10), an alternating-current motor (16), a speed-reducing mechanism for transmitting rotation of the motor (16) to the main shaft (14) while reducing a rotational speed of the motor (16) at a predetermined ratio, an electromagnetic brake (24) that applies a braking torque to the main shaft (14) when an excitation current is supplied thereto, a drive circuit (34) that supplies alternating-current power to the motor (16), and a brake circuit (36) that supplies the excitation current to the electromagnetic brake (24). When the loom (10) stops, the drive circuit (34) outputs an alternating-current voltage at a frequency corresponding to a synchronous speed lower than the actual rotational speed of the motor (16), so that the motor (16) generates a braking torque in a direction opposite to the rotating direction. In addition, the brake circuit (36) outputs the excitation current to stop the main shaft (14).