Model Breakdown:

• BH = Product Family (Frameless Brushless Servo Motor)
• 828 = Outer Diameter: 82mm / Inner Diameter: 28mm
• E = Electrical Length Code (Medium Torque Variant)
• 43 = Stack Length: 43mm
• B3 = Winding Configuration (Specific Kv/Torque Constant)
• E1 = Feedback Option: Multi-turn Absolute Encoder (BiSS-C / EnDat 2.2)

Technical Specifications:

Functional Features:

• Zero-backlash direct drive — motor mounts directly into the load.
• Hollow shaft design allows passage of cables, shafts, or cooling lines through the center.
• Multi-turn absolute encoder retains position after power-off — no homing required.
• High torque density: 41 Nm/L — among the highest in its class.
• Low cogging torque (< 1% of rated torque) for smooth low-speed operation.
• Corrosion-resistant laminations with N42SH neodymium magnets.

Working Principle:
The motor operates on the three-phase brushless DC (BLDC) / sinusoidal commutation principle. The stator contains 12 slots with 10 poles (or similar configuration). The rotor carries permanent magnets. The drive sends sinusoidal currents to the stator windings, creating a rotating magnetic field that interacts with the rotor magnets, producing torque. The absolute encoder mounted on the shaft provides real-time position feedback to the servo drive for closed-loop control.

Structural Features:

• Stator: Silicon steel laminations, epoxy-potted for vibration resistance.
• Rotor: Carbon-fiber retained sleeve with N42SH NdFeB magnets.
• Bearings: Not included — customer selects bearing set (typically angular contact ball bearings).
• Mounting: Press-fit into custom housing (OD) or clamped (ID).
• Shaft: Hollow bore — no output shaft (frameless design).

Material Composition:

• Stator Core: M19 silicon steel laminations (0.2mm thickness)
• Windings: Class H enamel copper wire (200°C rating)
• Magnets: N42SH Neodymium-Iron-Boron (NdFeB)
• Rotor Sleeve: Carbon fiber composite / Inconel 718 (varies by variant)
• Housing: No housing — frameless

Advantages:

• Eliminates mechanical transmission losses (gears, belts, couplings).
• Zero backlash — critical for precision positioning.
• Highest torque-to-inertia ratio in the 82mm frame class.
• Compact form factor saves machine envelope space.
• Absolute feedback enables instant-on operation.

Applicable Industries:

• Semiconductor wafer handling
• Robotic joints (6-axis and collaborative robots)
• Gimbal and antenna positioning
• Medical imaging (CT/MRI gantries)
• Aerospace actuation
• Optical gimbal systems

Installation Requirements:

• Press-fit stator OD into housing bore: interference fit of 0.01–0.03mm.
• Use torque-controlled press — maximum press force: 3 kN.
• Install angular contact ball bearings (e.g., 7005CD/P4A) on both sides.
• Preload bearings to 15–25 N axial preload.
• Ensure encoder cable exits through the hollow bore — minimum bend radius 30mm.
• Seal the motor from contaminants using custom labyrinth seal or O-ring.

Usage Precautions:

• Do not drop or impact the motor — magnet fracture risk.
• Do not exceed max speed of 6,000 RPM — centrifugal force can delaminate rotor.
• Ensure adequate cooling — continuous operation above 4,000 RPM requires forced air or liquid cooling.
• Demagnetization risk above 150°C rotor temperature — monitor with thermal sensor.
• Handle with ESD precautions — encoder electronics are sensitive.