AC Motor (Constant Speed Motor) Specifications

Description of Specification Items

Output Power

The amount of work that can be performed by a motor in a given period of time. It can be used as criteria for motor capability.

Rating

Indicates the amount of time the unit can be operated continuously at rated output power (torque). With a continuous rating, a motor can operate continuously.

Current

Indicates the current sent into the motor when the motor is producing the rated torque.

Starting Torque

Indicates the amount of torque that the motor exerts at the moment of startup, which can start up with a frictional load smaller than this value.

Rated Torque

Indicates the amount of torque generated when the motor is running at top efficiency.
Though the maximum torque is far greater, rated torque should, from the standpoint of utility, be the highest torque.

Rated Speed

Indicates the rotation speed used by a motor when the motor is producing the rated torque.

Permissible Torque of Gearhead Output Shaft

Indicates the magnitude of load torque that can be driven by the gearhead output shaft.

Electromagnetic Brake Static Friction Torque (Motor shaft)

Indicates the static friction torque of an electromagnetic brake (power off activated type), representing the magnitude of the holding torque at the motor output shaft.

Permissible Inertia J

When a high inertia (J) is connected to a gearhead, high torque is exerted instantaneously on the gearhead when starting in frequent, intermittent operations (or when stopped by an electromagnetic brake, or when stopped by a brake pack, etc.). Excessive impact loads may result in damage to the gearhead and motor.
The permissible inertia for three-phase motors is the value when reversing after a stop.
The lifetime is 2,000,000 cycles when operating permissible inertia using electromagnetic brake motors, brake packs, and speed control motors with instantaneous stop.

Gearhead Maximum Permissible Torque

Output torque of the gearhead increases in proportion to the increase in the gear ratio.
However, the size of the load torque applied to the gearhead is saturated at a certain gear ratio because of the gear material and other conditions. This torque is called the maximum permissible torque.
The maximum permissible torque of typical gearheads is shown in the figure to the right.