Technical Specifications:

Holding Brake Specifications:

• Type: Spring-Applied, Electrically Released (Fail-Safe)
• Holding Torque: 36 Nm
• Release Time: ≤ 40 ms
• Engagement Time: ≤ 20 ms
• Brake Voltage: 24 V DC
• Brake Current: 0.6 A (Holding)
• Safety Rating: Per EN 61800-5-2 (STO — Safe Torque Off Compatible)

Encoder Specifications:

• Type: Incremental Optical Encoder, Multi-Turn Capable (with Battery Backup Option)
• Resolution: 2048 PPR / 8192 Edges (×4)
• Output: HTL, RS-422 Differential (Line Driver)
• Supply Voltage: 5 V DC ±5%
• Maximum Frequency: 300 kHz

Functional Features:

• High Power Density — 4.0 kW continuous power in compact BM4 housing
• Forced Air Cooling (IC416) — Maintains full torque at all speeds up to nmax
• Fail-Safe Holding Brake — Mechanical position lock without power, STO-compatible
• Robust Shaft Design — Oversized shaft diameter (Ø28 mm) for high radial loads
• Multi-Turn Encoder Option — Absolute position retention after power loss (with battery)
• High Overload Capacity — 300% peak torque for 0.5 seconds
• Low Torque Ripple — < 2% of rated torque (cogging-free design)

Structure & Material Composition:

• Stator: Grain-Oriented Silicon Steel, 0.35 mm Laminations, Vacuum-Impregnated (VPI)
• Rotor: NdFeB Magnets, Grade N42SH, Carbon Fiber Sleeve (High-Speed Retention)
• Housing: Aluminum Alloy Die-Cast (ADC12), Black Anodized, RAL 9005
• Brake Assembly: Cast Iron Brake Disc, Spring Steel Brake Pads
• Shaft: Alloy Steel (42CrMo4 / 1.7225), Hardened to 58-62 HRC, Keyway DIN 6885-1
• Bearings: Cylindrical Roller Bearings (NU207 ECP) + Angular Contact Ball Bearing (7207 BEP)
• Connector: M23 19-Pin Connector, IP67 Rated

Working Principle:
The BM4773 is a high-power synchronous servo motor. Three-phase AC power (or DC bus via inverter) energizes the stator windings, producing a rotating magnetic field that drives the NdFeB permanent magnet rotor. The incremental encoder provides high-resolution position feedback for closed-loop vector control. The holding brake mechanically clamps the shaft via spring force when de-energized. Forced air cooling (external fan or blower) is required to dissipate heat at continuous rated power. The servo drive executes FOC (Field Oriented Control) with automatic flux weakening above rated speed.

Applicable Industries:

• Heavy-Duty CNC Machine Axes
• Press and Stamping Machines
• Large Injection Molding Machines
• Printing Press Drives
• Steel Mill Equipment
• Wind Turbine Pitch Control
• Marine Propulsion (Auxiliary)

Installation Requirements:

• Mounting: Flange Mount (B5), 8 Mounting Holes, 190 mm Bolt Circle Diameter
• Cooling: Mandatory Forced Air Cooling — Minimum 15 m/s Airflow at Rated Load
• Ambient Temperature: -10°C to +40°C (Derating Required Above 35°C)
• Shaft Alignment: ≤ 0.03 mm Radial, ≤ 0.02° Angular
• Bolt Torque (M10): 80 Nm
• Brake Wiring: Shielded Cable, Maximum 50 m Length

Usage Precautions:

• Forced air cooling is mandatory — do not operate without cooling fan at rated load
• Brake release signal must be verified before enabling drive output
• Maximum continuous operating temperature (winding): 155°C (Class F)
• Do not exceed 300% peak torque for more than 0.5 seconds
• Bearing relubrication interval: 15,000 hours (sealed, maintenance-free design)
• Vibration limit: 3 m/s² RMS (exceeding this voids bearing warranty)