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Servo Motors

FANUC’s servo motors feature high reliability, easy maintenance and exceptional electrical efficiency. Our servo motors are designed and manufactured with a focus on the ultimate in performance, reliability and efficiency. Our powerful high-speed machining technology and energy efficiency functions vastly reduce cycle times while ensuring a high degree of accuracy and precision.


Types of FANUC Servo Motors

BETA i-B Series Servo Motors

FANUC produces four types of servo motors. Our BETA i-B Series servo motors offer a significant performance-to-cost ratio, making them ideal for entry-level machines.

FANUC’s BETA i-B Series servo motors are highly reliable motors ideal for feed axes of entry-level machines, positioning axes and peripheral units. This series’ pulsecoder and special magnetic pole shape, which minimizes cogging torque, and the latest SERVO HRV+ Control achieve extremely smooth motor rotation, enabling machining of very high precision and quality.

Our BETA i-B Series servo motors’ unique seal structure offers high-quality waterproofness. This feature helps businesses keep downtime to a minimum.

BETA i-B Series servo motors feature:

  • Medium inertia with quick acceleration
  • Available in two versions: F (ferrite magnet) and S (strong motor with neodymium magnets)
  • 200V or 400V input voltage
  • Torque output 0.2-40 Nm
  • Smooth rotation
  • Up to 6,000 rpm
  • High resolution βi Series encoder (1 million pulses per revolution standard, 4 million optional)
  • IP65 protection standard, with IP67 optional

ALPHA i-B Series Servo Motors

Our ALPHA i-B Series servo motors deliver ultra-smooth rotation and superior acceleration for compact high-speed and precision machines.

The FANUC ALPHA i-B Series servo motors offer exceptional performance, enabling high-speed, high-precision machining on machines of all sizes. This series’ excellent torque characteristics provide quick acceleration to high-speed range, helping decrease cycle time. ALPHA i-B Series servo motors’ pulsecoder, unique magnetic pole shape and SERVO HRV+ Control achieve tremendously smooth motor rotation for high-precision and high-quality machining.

As with our BETA i-B Series, our ALPHA i-B Series servo motors’ seal structure offers exceptional waterproofness, helping minimize downtime.

ALPHA i-B Series servo motors feature:

  • Supremely smooth feed
  • Two versions: F (ferrite magnet) and S (strong motor with neodymium magnets)
  • 200V or 400V input voltage
  • Torque output from 1–3,000 Nm
  • Speeds up to 6,000 rpm
  • High-resolution αi Series encoder (4 million pulses per revolution standard, 32 million optional)
  • IP65 protection standard, with IP67 optional

DiS-B Series Servo Motors

FANUC’s Direct Drive DiS-B Series servo motors are ideal for rotary tables and axes; they offer huge amounts of torque with an extremely smooth feed while achieving high speed, high precision and maintenance-free operation.

FANUC’s Direct Drive DiS-B Series synchronous, built-in torque servo motors are ideal for rotary tables and rotary axes for 5-axis machines. Rare-earth magnets help deliver high torque, and the motor ampilifer’s circuit design mitigates torque ripple. Our DiS-B Series servo motors can either be air-cooled or, for increased performance, oil- or water-cooled.

DiS-B Series servo motors feature:

  • Neodymium magnets to provide high torque
  • Available with 200V or 400V input voltage
  • Maximum torque from 35–10,000 Nm
  • Continuous torque from 15–4,500 Nm
  • High-speed models up to 3,000 rpm
  • Optimum magnetic circuit design provides low ripple
  • Maintenance-free direct drive

LiS-B Series Servo Motors

The Linear LiS-B Series servo motors work without force transmission mechanisms to simplify machine design and maintenance and provide massive amounts of thrust force.

FANUC’s LiS-B Series linear motors have set new standards for acceleration, precision and speed, delivering high gain and rigidity with excellent path accuracy. Unlike conventional drives, these motors work without any force transmission mechanisms, making machine design and maintenance easier (no ball screws, no backlash). The linear design enables rigid long-stroke axes, increased thrust force and multi-head configurations by arranging multiple coil sliders on a single magnet track.

LiS-B Series servo motors feature:

  • High rigidity allows higher speeds (4m/s) and higher acceleration (30G)
  • Any number of coil sliders can be installed on a single magnet plate track for multi-head configuration
  • Stroke length determined by number of magnet plates used and limited only by length of linear encoder selected; unlike conventional ball screw systems, adding length does not increase load inertia or reduce rigidity
  • Linear motors can be placed in series or parallel arrangements for maximum design flexibility; they can even be arranged opposing each other to counteract their magnetic attraction force
  • Water cooling allows for large continuous force from 100–7,750 N
  • High precision by applying linear scales with high resolution
  • Maintenance-free mechanism

Commonly Asked Questions about Servo Motors

  • What is a servo motor?

    A conventional servo motor converts electrical energy into rotational motion. It comprises stator windings and housing, permanent magnet rotor and laminates, pulse coder and end rear bell along with front and rear bearings.

    The stator windings and housing represent the electromagnetic part of the servo motor. Its C-face mounting secures it to the frame of a machine or load that is to be controlled. Its ferrous core, made of steel laminates, focuses the magnetic field produced when electrical current flows in the copper winding. Embedded in the stator laminates, the copper winding is a 3-phase winding in FANUC’s star configuration. For each revolution of output from a servo motor, the 3-phase input power must be cycled four times. Hence, FANUC servo motors are built in what’s referred to as quadrature.

    The motor rotor is the rotating part of the motor that is usually coupled to a ball screw. It is made of an output shaft that is centered in an iron mass constructed of steel laminates. The rotor is suspended by a pair of bearings holding the output shaft in the center of the stator. The rotor’s magnetic field is made of permanent magnets that are embedded in the rotor. Usually, four pairs of north-south magnets exist, making most FANUC servo motors 8-pole motors.

  • How Does a Servo Motor Work?

    To cause motion between the permanent and electromagnet magnets used in a typical servo motor, current must be applied to the electromagnet’s winding. This causes a magnetic field to be generated around the conductor carrying the current. The magnetic field generated by passing current through a conductor will change polarity, depending on the direction of the current flow. The magnetic field induced by the wire is not enough to cause the second magnet to move.

    To amplify the magnetic field, the wire is stacked upon itself multiple times. By doing so, the magnetic field is multiplied by the number of wires stacked in the coil. Additionally, the winding is mounted with an iron center, further focusing the generated magnetic field. When passing current through a coil of wire with an iron core center, a strong magnetic field is generated. Once we have a magnetic field generated by the electromagnet, the permanent magnet reacts to it. The amount of attracting or repelling force generated by the magnets matches the two magnets’ strength.

  • Where are servo motors used?

    Servo motors deliver superb acceleration and are valued for their first-rate performance, reliability and efficiency. Servo motors are used in any application requiring smoothness, precision, repeatability and dependability.

    Servo motors don’t just have special application in CNC machinery, robotics and automated manufacturing; these motors are used in antenna positioning devices, cameras, conveyor belts, door openers and in many other business and consumer products and applications. FANUC servo motors are used worldwide and have earned a reputation for their consistently high level of build quality, producing exceptional performance with extraordinary efficiency.

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