MTWB 6804 Decoder Bearing is a precision sensor-integrated ball bearing engineered for AC induction motor speed and direction feedback in electric vehicles, forklifts, material handling equipment, agricultural machinery, and industrial motion control systems. Unlike standard deep groove ball bearings, the decoder bearing integrates a magnetic encoder ring with the bearing's rotating inner ring, working in conjunction with a Hall-effect sensor to generate incremental quadrature signals proportional to rotational speed and direction.
Key Search Terms: 6804 decoder bearing, sensor bearing 20x32x7mm, motor speed feedback bearing, Hall effect encoder bearing, AC motor decoder unit, MTWB sensor bearing.
Parameter Value
Bearing Designation 6804 Decoder Bearing
Bore Diameter (d) 20 mm (0.7874 in)
Outer Diameter (D) 32 mm (1.2598 in)
Width (B) 7 mm (0.2756 in)
Radius (r min) 0.5 mm
Dynamic Load Rating (Cr) 900 lbs (approx. 4.0 kN)
Static Load Rating (C0r) 555 lbs (approx. 2.47 kN)
Weight 0.019 kg (0.042 lbs)
Bearing Type Single-row deep groove ball bearing with integrated encoder
Encoder Type Magnetic ring encoder (ferrite or rare-earth magnet)
Sensor Compatibility Hall-effect sensor, incremental output (A/B channels)
Signal Output Quadrature square wave, frequency proportional to rotational speed
Speed Range Up to 24,000 RPM (model dependent)
Operating Temperature −40°C to +150°C (standard); up to 350°C available on request
Precision Grade P6 (ABEC 3) standard; P5 / P4 available on request
Noise Level ZV3 (ultra-low noise grade)
Lubrication Low-noise grease, sealed for life
Sealing 2RS (double rubber seals) or ZZ (metal shields) available
The dimensional data is based on standard 6804 deep groove ball bearing geometry: 20 mm × 32 mm × 7 mm, with a dynamic load capacity of 900 lbs and static load capacity of 555 lbs. MTWB further refines the raceway geometry and surface finish to optimize the decoder function while maintaining the load-carrying capability of the base bearing.
1. Integrated Speed & Direction Sensing
The decoder ring is precision-mounted on the bearing inner ring, creating a stable magnetic field pattern that rotates with the shaft. The stationary Hall-effect sensor detects the field variations and outputs a two-channel quadrature signal (A/B channels, 90° phase shift), enabling the control system to determine both rotational speed and direction without additional mechanical components.
2. Enhanced EMI/EMC Immunity
The encoder unit is designed to resist electromagnetic interference from motor windings and power electronics. Shielded encoder housing and optimized sensor placement ensure reliable signal output even in high-current switching environments typical of AC induction motor drives.
3. Ultra-Low Noise Operation (ZV3 Grade)
MTWB applies superfinished raceway surfaces and tightly controlled geometric tolerances to achieve ZV3 noise rating. This is critical for decoder applications in passenger electric vehicles and indoor material handling equipment where acoustic comfort is a requirement.
4. High-Speed Capability
The 6804 decoder bearing supports rotational speeds up to 24,000 RPM (open configuration), making it suitable for high-speed motor shafts in EV traction motors and compact industrial drives.
5. Robust Sealing & Contamination Protection
Standard 2RS double rubber seals prevent ingress of dust, moisture, and metal particles that could disrupt the magnetic encoder signal or damage the bearing. ZZ metal shields are also available for lower-torque applications.
6. Compact & Lightweight
At 0.019 kg per unit, the 6804 decoder bearing minimizes rotating mass on the motor shaft, contributing to faster dynamic response and reduced energy consumption.
Industry Typical Application
Electric Vehicles Traction motor speed feedback, wheel hub motor sensing
Material Handling Forklift drive motor control, conveyor speed monitoring
Agricultural Machinery Seeder motor feedback, harvester drive control
Industrial Automation Servo motor feedback, robotic arm joint sensing
Small Electric Vehicles Golf cart motor control, personal mobility devices
HVAC & Pumps Variable-frequency drive motor speed feedback
Medical Equipment Precision motor positioning and speed regulation
Decoder bearings are specifically used as feedback sensors in AC induction motor control systems. The integrated encoder allows the frequency converter to accurately control stator frequency and slip, enabling maximum torque production across the full speed range.
1. 30+ Years of Customized Bearing Engineering
MTWB (Mighty Way Industrial Limited) has been a specialized manufacturer of micro-size, low-noise ball bearings and flanged thin-section bearings since 2015, with bearing customization expertise accumulated over three decades of engineering practice. The 6804 Decoder Bearing benefits from this deep application knowledge.
2. 51 Active Patents — 10 Product Innovation Patents
MTWB holds 51 active patents, including 10 product innovation patents. The decoder bearing design leverages proprietary raceway geometry optimization and encoder mounting techniques developed in-house.
3. In-House Encoder Integration Capability
Unlike trading companies that outsource encoder assembly, MTWB performs encoder ring magnetization, sensor alignment, and signal verification within its own production lines. This ensures consistent phase accuracy (± 5° electrical) and signal amplitude across every unit.
4. Custom Material Options
Beyond standard GCr15 bearing steel, MTWB offers martensitic stainless steel (SV30), ceramic, and specialty alloy options for decoder bearings operating in corrosive, high-temperature, or non-magnetic environments.
5. Rapid Prototyping for OEM Programs
MTWB's customization workflow — design, technical drawing, customer confirmation, sample making, to small-batch production — is specifically optimized for OE customers developing new motor platforms. Lead times are significantly shorter than international brand equivalents.
6. 100% Noise & Signal Testing
Every decoder bearing undergoes 100% noise inspection (ZV3 grade) and signal output verification before shipment, ensuring zero-defect delivery for motor control applications.
7. Global OEM Track Record
MTWB bearings are already successfully deployed by major OEMs and distributors in America and Europe for over a decade, with 100+ active OEM customers.
October 14,2026
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