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B-204-A-99-056 Kollmorgen

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The Kollmorgen B-204-A-99-056 is part of the Goldline B and BH Motors series and has a continuous stall torque of 4.47 Newton-meters. This motor features a back EMF constant of 100.5 Vrms per kRPM and operates with a DC resistance of 9.46 ohms. It has a torque constant of 1.66 Newton-meters per Arms and accommodates 4 poles.

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Product Description:

The B-204-A-99-056 is a brushless servo motor built by Kollmorgen as part of the Goldline B and BH Motors series. Intended for closed-loop motion axes, the unit converts drive current into controlled shaft torque and speed for pick-and-place modules, conveyors, and other positioning stages within industrial automation systems. This permanent-magnet motor is commonly paired with Servostar and AKD drives, creating a matched electromechanical package for repeated production duty. Its brushless design also supports accurate response with low maintenance because there are no brushes to wear during normal operation.

A continuous stall torque of 4.47 N-m is the sustained load the shaft can hold without motion when current is regulated at rated temperature. The torque constant of 1.66 N-m/Arms translates drive current into rotational force, which helps the drive produce predictable torque output. A back-EMF constant of 100.5 Vrms/kRPM shows the voltage generated per thousand revolutions and is useful when matching motor speed to the available drive bus voltage. Electrical behavior is influenced by the phase resistance of 9.46 ohms and the winding inductance of 133 mH, which affect current ripple, transient response, and heat generation. At 25 °C, the motor can withstand a momentary stall torque of 4.7 N-m, giving a small margin above the continuous value for intermittent duty.

The rotor’s mass moment of 0.000173 kg·m² supports rapid speed changes, and when combined with the four-pole magnetic structure it allows a calculated theoretical acceleration of 79200 rad/s² at peak current. That low inertia can be helpful in systems that start, stop, and reverse frequently during short indexing moves. Drive bus limits must remain below 250 Vrms line to line, which is the maximum voltage the insulation system can tolerate. Static friction is specified at 0.1 N-m, so the control loop can overcome stiction with only a small torque offset. Heat produced during operation leaves the frame through a thermal path rated at 0.74 °C/W, allowing continuous running in ambient air up to 40 °C without additional cooling.

Ambient Temp
40 °C
Back Emf Constant
100.5 Vrms/kRPM
Continuous Stall Torque
4.47 N-m
Dc Resistance
9.46 ohms
Inductance
133 mH
Max Line-to-line Volts
250 Vrms
Max Theoretical Accel
79200 rad/s²
Number Of Poles
4
Rotor Inertia
0.000173 kg-m²
Stall Torque At 25 C
4.7 N-m
Static Friction
0.1 N-m
Thermal Resistance
0.74 °C/W
Torque Constant
1.66 N-m/Arms
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Frequently Asked Questions about B-204-A-99-056:

Q: What is the continuous stall torque of the B-204-A-99-056 motor?

A: The B-204-A-99-056 provides a continuous stall torque of 4.47 N-m for reliable performance under load.

Q: What is the maximum ambient temperature for reliable operation of the B-204-A-99-056?

A: This model operates at ambient temperatures up to 40 °C.

Q: What is the back EMF constant of the B-204-A-99-056 servo motor?

A: The back EMF constant for this model is 100.5 Vrms per kRPM.

Q: What is the highest line-to-line voltage the B-204-A-99-056 can handle?

A: The maximum allowable line-to-line voltage for the B-204-A-99-056 is 250 Vrms.

Q: What is the rotor inertia value of the B-204-A-99-056?

A: This motor features a rotor inertia of 0.000173 kg-m², supporting fast response in dynamic applications.


Internal Product Review

  • ‘‘The B-204-A-99-056 is a Kollmorgen Goldline B and BH motor with 4.47 N-m continuous stall torque and a 1.66 N-m/Arms torque constant. A 100.5 Vrms/kRPM back EMF constant paired with 133 mH inductance supports stable, controlled servo performance. Strong torque output and predictable electrical behavior make the motor a very capable choice for demanding motion applications.’’

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