Kollmorgen 6SM71M-3000 servo current voltage

Description

Kollmorgen 6SM71M-3000 servo current voltage

“Holding torque” and the corresponding rated current are leading specifications for selection in the ratings tables for all motors. Holding torque is often used as a figure of merit when comparing motors. It specifies the maximum external torque that can be applied to a stopped motor with rated current applied without causing the motor to rotate continuously. When the motor begins to rotate the torque available is often referred to as “pullout torque.” Pullout torque ratings correspond to values shown in performance speed/torque curves. At starting speeds the pullout torque is typically 20-30% lower than the motor’s rated holding torque.

Stepper drives amplify and send DC current and voltage into the motor windings. Kollmorgen stepper motors are used with a variety of drives available from Kollmorgen and other manufacturers. These drives typically have a broad range of voltage and current ratings. A motor’s performance is highly dependent on the current and voltage supplied by a drive. For even finer resolution and smoother operation, micro-stepping drives divide each step into many increments by controlling the magnitude of the current in each winding.

The terms full-step, half-step and “microstep” are commonly used in the discussion of step motors. A 1.8° step motor, for example, has 200 discrete positions in a full 360° revolution. Since 360° divided by 200 equals 1.8°, the motor shaft will advance 1.8° each time the motor is given a digital command to take one step. This is known as a full-step. The term “half-step” indicates a 0.9° step angle (half of a full 1.8° step). This is achieved with a switching technique that alternately applies positive current, no current, and negative current to each winding in succession.

The term “microstep” refers to a more sophisticated form of control which goes beyond the simple switching of power between phase A and phase B of the motor windings, and takes control of the amount of current being sent to the individual windings. Microstepping permits the shaft to be positioned at places other than the 1.8° or 0.9° locations provided by the full-step and half-step methods. Microstepping positions occur between these two angular points in the rotation of the rotor. The most commonly used microstep increments are 1/5, 1/10, 1/16, 1/32, 1/125 and 1/250 of a full step. A major benefit of microstepping is that it reduces the amplitude of the resonance that occurs when the motor is operated at its natural frequency or at sub-harmonics of that frequency. The improved step response and reduced amplitude of the natural resonances result from the finer step angle.