Fanuc AC Servo Motor A06B-0223-B000 A06B0223B000 AO6B-O223-BOOO

Part Number: A06B-0223-B000

Also Searched As: A06B0223B000, Fanuc A06B-0223-B000, FANUC A06B0223B000

Motor Model: αiF 4/5000

Classification: Fanuc Alpha iF Series AC Brushless Servo Motor — 4 Nm Stall Torque, 5,000 rpm, Taper Shaft with Key, No Brake, Absolute A1000 Pulse Coder, IP65

The Fanuc A06B-0223-B000 is an αiF 4/5000 AC servo motor — a capable mid-range motor from Fanuc's alpha iF series that shows up on a remarkably wide variety of Fanuc-controlled machine tools. With 4 Nm stall torque, a 5,000 rpm rated speed, and a taper shaft with key as standard, this motor covers the performance requirements of light-to-medium CNC feed axes across small and medium-format machining centres, turning centres, and drilling machines.

Three things define its configuration. The taper shaft delivers the precise, self-centring interface that machine tool servo coupling requires. The Alpha i A1000 absolute pulse coder at 1,000,000 pulses per revolution means the machine knows exactly where it is the instant power comes on — no homing cycle needed. And the B000 suffix confirms no electromagnetic brake, which is the correct choice for horizontal axes that hold position through Fanuc servo lock at rest.

The αiF designation places this motor in a specific category within Fanuc's servo motor lineup. The "4" in the model name is the stall torque in Newton-metres — the maximum torque the motor sustains at zero speed before reaching thermal limits. The "5000" is the rated speed in rpm. Together, they define the motor's working envelope.

Four Newton-metres of stall torque handles the low-speed, high-load phases of a machining cycle — deep drilling passes, heavy facing cuts, sustained feed under cutting load. On a 4mm pitch ball screw at 90% efficiency, 4 Nm sustains approximately 5.6 kN of axial force at low speeds. That's a realistic budget for small-to-medium machining centre feed axes carrying moderate table and workpiece mass.

The 5,000 rpm rated speed is where this motor distinguishes itself from the 4,000 rpm motors that dominate the mid-range αiS family. At 5,000 rpm on a 4mm pitch ball screw, the axis moves at 20 m/min in direct coupling — fast enough to make rapid traverse genuinely rapid on a compact machine. For smaller machines where cycle time is a competitive concern and axis travel is short, that traversal speed has production value.

This combination — 4 Nm sustained force capability, 5,000 rpm traversal speed, 1.4 kW rated output — fits the performance requirements of a broad population of CNC machine tool feed axes. It is not a coincidence that the A06B-0223 series appears on such a wide variety of equipment.

The taper shaft on the A06B-0223-B000 is the standard Fanuc shaft configuration for machine tool servo axes, and understanding what it delivers helps explain why it is specified as the default rather than a straight shaft.

A taper shaft is a precisely ground cone, matched to a corresponding bore in the coupling hub or ball-screw coupling assembly. When the hub is pulled onto the taper with a draw bolt through the shaft-end thread, the taper geometry centres the hub automatically — the motor and driven shaft axes align to a tight geometric tolerance without adjustment. The key in the shaft keyway then transmits torque mechanically, independently of the axial clamping force.

This matters for two practical reasons. First, accurate shaft alignment at installation reduces radial load on the motor's front bearing and avoids introducing backlash into the axis. Second, when the motor is removed for service and reinstalled — or replaced with a fresh unit — the taper ensures the replacement seats identically to the original without shimming or alignment verification. For a machine tool manufacturer designing a motor mount, taper shaft standardisation means the same coupling hub works across all motors in the αiS/αiF family at a given frame size.

The included key is essential. Without it, all torque transmission would depend on taper clamping friction alone, which is not adequate under the cyclic reversal and shock loads a machining axis experiences. The key-and-taper combination is mechanically robust across the full operating life of the motor.

The B000 designation means this motor carries no electromagnetic brake. Position at rest is maintained by the Fanuc αi servo amplifier's servo lock — the position loop remains active, the A1000 pulse coder continuously monitors shaft angle at 1,000,000 counts per revolution, and the amplifier delivers corrective current to hold zero following error.

On horizontal axes — the X and Y table drives, saddle feeds, and carriage axes that make up the majority of machine tool servo applications — this is entirely adequate. The servo lock hold is tight, the axis does not drift, and the machine coordinate remains valid across any rest period while power is on.

The no-brake configuration also keeps installation cleaner. There is no 24V DC brake circuit to wire in the panel, no brake relay to specify and mount, no brake release timing to programme into the CNC startup sequence, and no brake disc wear to monitor over the motor's service life. On a machine with eight or ten servo axes, those simplifications add up.

When a machine axis has a gravitational load component — a vertical Z-axis carrying spindle head mass, an inclined feed with a weight component along the axis direction — servo lock is not adequate at servo-off. Those applications require a braked motor variant. Within the A06B-0223 series, the B400 (straight smooth shaft, 24V brake) and B500 (straight keyed shaft, 24V brake) carry electromagnetic brakes for vertical axis applications. The B000 is the correct and preferred specification for horizontal axes.

The encoder fitted to the A06B-0223-B000 is the Alpha i A1000 — Fanuc's serial absolute encoder at 1,000,000 pulses per revolution. The "A" prefix is what matters: this is an absolute encoder, not an incremental one.

• Absolute means no homing: Every time the Fanuc CNC powers up, the αi servo amplifier reads the A1000's position data immediately. The encoder retains its multi-turn count through power-off events, backed by a battery in the servo amplifier or CNC cabinet battery unit. The CNC establishes the machine coordinate of every axis at power-up without any axis movement. On a machine with multiple servo axes, this eliminates a potentially lengthy homing sequence and gets the machine into production in seconds rather than minutes.
• One million pulses per revolution: At 1,000,000 counts per revolution on a 4mm pitch ball screw, each encoder count corresponds to 4 nanometres of linear displacement. The Fanuc servo's position loop closes at this resolution — fine enough for the sub-micron positional repeatability that precision CNC machining centres advertise. The velocity feedback loop uses the same fine resolution to produce smooth, ripple-free speed output at any feed rate from the slowest finishing pass to maximum rapid traverse.
• Battery backup: The multi-turn absolute counter is maintained through power-off by a backup battery in the Fanuc αi servo amplifier. Replace it when the Fanuc CNC displays a battery alarm. A fully discharged battery resets the multi-turn count and requires a reference-return cycle before the machine can resume production — a disruption that a timely battery replacement prevents entirely.

The B000 is the clean baseline — taper shaft, no brake, absolute encoder. It is the right motor for the horizontal axis applications that most Fanuc machine tools have in the majority of their axes.

The A06B-0223-B000 operates with Fanuc αi series servo amplifiers (αiSV) — the αiSV 4 or αiSV 8 depending on the machine's axis configuration and peak current requirements. The A1000 pulse coder communicates over Fanuc's standard αi serial encoder protocol, supported by all αi-generation amplifiers.

Compatible CNC platforms: Fanuc Series 0i-D, 0i-F, 15i, 16i, 18i, 21i, 30i-A, 30i-B, 31i-A, 31i-B, and 32i.

The motor is not compatible with older first-generation α or αC series amplifiers that use a different encoder interface, nor with Fanuc β series drives.

When fitting the A06B-0223-B000 as a replacement, verify the CNC axis parameters are set to the αiF 4/5000 motor type from Fanuc's servo parameter database. Incorrect motor type parameters produce unstable servo performance or amplifier faults on startup.

• Small and medium CNC machining centre feed axes: X and Y table and saddle drives on vertical machining centres ranging from compact benchtop mills to medium-format machines with tables up to 500 × 400 mm. The 4 Nm stall torque handles reasonable table mass and cutting loads; the 5,000 rpm rated speed provides fast rapid traverse on these typically short-axis machines.
• CNC turning centre carriage and cross-slide axes: Z-axis carriage drives and X-axis cross-slide drives on compact CNC turning centres where the taper shaft interface connects directly to the ball-screw coupling, and the 5,000 rpm rating provides rapid traverse across the workpiece diameter range.
• CNC drilling and tapping machine axes: X-Y positioning axes on CNC drilling centres and tapping machines where speed between hole locations drives cycle time. The 5,000 rpm motor traverses at maximum speed on short-pitch ball screws, reducing the inter-hole positioning time that accumulates across a full workpiece.
• Fanuc robot axis drives: Select Fanuc robot joints and positioning axes using αi series amplifiers specify αiF series motors. The taper shaft interface and A1000 absolute encoder suit robot applications where accurate position retention through power-off events is a functional requirement.
• General Fanuc αi platform automation: Any Fanuc αi amplifier-equipped automation system requiring 4 Nm servo force at up to 5,000 rpm, with a taper shaft output, absolute position feedback, and established Fanuc parameter database support.