OTC DAIHEN FD11-A20 Industrial Robot Mechanical Structure & Maintenance Parts Analysis
In the OTC DAIHEN automated laser welding, precision cutting, and medium-payload arc welding applications, the FD11-A20 Industrial Robot (equipped with a 20kg payload arm) is widely deployed in frontline manufacturing cells thanks to its extremely high dynamic trajectory motion rigidity and exceptional repeat positioning accuracy. Its lower heavy-duty axes (J1, J2, J3) are fully equipped with high-torque cycloidal gearboxes (high-rigidity, large-capacity design), while the upper wrist axes (J4, J5, J6) integrate lightweight harmonic gearboxes and highly flexible timing transmission belts.
After long cycles of high-speed, highly dynamic operation, the dedicated lubricating grease inside each joint’s gearbox (such as 100-0127 cycloidal grease and 2670-053 harmonic grease) will gradually degrade. Routine major overhauls, core motor replacement, belt tension compensation, and quick replacement of highly flexible internal bus cables are mandatory to maintain the equipment’s low backlash. Below is an exact model reference list of all official original factory parts for the FD11-A20 main body:
📷 Figure 1: OTC DAIHEN FD11-A20 Industrial Robot Axis Skeleton Mechanical Exploded View
2. FD11-A20 Core Electromechanical Parts Global Selection Matrix by Axis
To completely eliminate layout misalignment, we have integrated 8 scattered sub-tables into a single high-precision comprehensive master table. The first column “Image Ref.” has been enlarged and bolded for clarity. The equipment maintenance department should strictly cross-reference the circled symbols in Figure 1 for accurate verification:
| Image Ref. | Axis / Location | Official Part Number | Standard Part Name | Function & Quantitative Maintenance Notes |
|---|---|---|---|---|
| ① | J1 Axis (Rotating Base) |
W-L02152 | AC Servomotor | Core drive source controlling horizontal base rotation. |
| ② | W-L02715 | Cycloidal Gearbox | Rigid base reducer bearing the entire machine’s gravity. | |
| ③ | 100-0127 | Lubricating Grease (860ml) | High-wear-resistance, large-capacity liquid gearbox grease dedicated for J1 axis. | |
| ④ | J2 Axis (Lower Arm Pitch) |
W-L02654 | AC Servomotor | Provides high-dynamic main power for lower arm forward/backward pitch. |
| ⑤ | W-L02714 | Cycloidal Gearbox | Core high-torsion, large-capacity reducer for the lower arm joint. | |
| ⑥ | W-L02551 | Crossed Roller Bearing | Precision bearing carrying the combined axial and radial loads of the lower arm. | |
| ③ | 100-0127 | Lubricating Grease (690ml) | Specified grease volume injected into the J2 bearing pressure cavity. | |
| ⑦ | 100-1491 | Lubricating Grease (4ml) | Trace grease replenishment for specific mating surfaces or sealed bearings. | |
| ⑧ | J3 Axis (Upper Arm Pitch) |
W-L02641 | AC Servomotor | High-dynamic response motor providing upper arm up/down pitch. |
| ⑨ | W-L02713 | Cycloidal Gearbox | Precision cycloidal reducer driving the upper arm’s extension and retraction. | |
| ③ | 100-0127 | Lubricating Grease (345ml) | Specified grease volume for J3 bearing pressure cavity. | |
| ⑲ | L11710C06 | Protective Film | Dedicated industrial protective film protecting axis surfaces or seals. | |
| ⑥ | J4 Axis (Arm Rotation) |
W-L02551 | Crossed Roller Bearing | J4 rotary bearing, sharing the dynamic lateral turnover moment caused by the long cantilever. |
| ⑩ | W-L02151 | AC Servomotor | Main drive servo motor providing wrist rotation. | |
| ⑪ | W-L02113 | Harmonic Gearbox | High-precision, lightweight cup-shaped harmonic drive for the upper arm. | |
| ⑦ | 100-1491 | Lubricating Grease (4ml) | Trace grease for specific contact surfaces. | |
| ⑫ | 2670-053 | Lubricating Grease (5ml) | High-viscosity, anti-fatigue lubricating grease dedicated for harmonic flexsplines. | |
| ⑩ | J5 Axis (Wrist Pitch) |
W-L02151 | AC Servomotor | Drive source for wrist pitch angle. |
| ⑬ | W-L02114 | Harmonic Gearbox | Large transmission ratio reducer for wrist pitch. | |
| ⑭ | W-L02028 | Timing Belt (1) | J5 axis highly flexible synchronous power transmission toothed belt. | |
| ⑮ | 100-1516 | Sealant (10ml) | Original factory high-temperature anaerobic sealant to prevent wrist oil cavity leakage. | |
| ⑫ | 2670-053 | Lubricating Grease (5ml) | Ultra-fine lubricating grease dedicated for wrist harmonic drives. | |
| ⑩ | J6 Axis (Flange Rotation) |
W-L02151 | AC Servomotor | Controls the high-frequency rotation of the end welding torch or tool flange. |
| ⑯ | W-L02115 | Harmonic Gearbox | Extremely low backlash harmonic drive for the end axis. | |
| ⑰ | W-L02029 | Timing Belt (2) | J6 axis synchronous transmission toothed belt for high-cycle, fast start-stop operations. | |
| ⑮ | 100-1516 | Sealant (10ml) | Anti-oil leakage sealant for end cover. | |
| ⑫ | 2670-053 | Lubricating Grease (5ml) | Dedicated anti-friction grease for end high-flexspline friction pair. | |
| ⑲ | Cables & Accessories (Global System) |
W-L02722 / W-L01399C | Battery (3-Cell Pack) | Backup lithium battery pack maintaining the spatial coordinate memory of core absolute encoders. |
| — | L11710F00 | Cable Assembly (1) | Highly flexible main cable bus routing from the rear of the base rack through to the inside of the upper arm. | |
| — | L10485G00 | Cable Assembly (2) | Encoder feedback cables specifically for J5 and J6 axis motors at the front of the upper arm. | |
| — | L11440R00 | Cable Assembly (4) | Dedicated high-voltage power supply line for J2 axis AC servo motor. | |
| — | L11440G00 | Cable Assembly (5) | High-sensitivity encoder signal feedback shielded cable for J2 axis motor. | |
| — | L10485B00 | J5, J6 Axis Unit Assembly | Entire wrist end mechanical housing and core joint assembly. |
* Note: Items with an “Image Ref.” of “—” in the table represent wiring harnesses and power cables hidden inside the main body, which cannot be visually indicated in the external skeleton exploded view. Please perform disassembly and replacement according to the original factory manual.
💡 FD11-A20 20kg Heavy-Payload Robot Mechanical Overhaul & Maintenance Red Card Warnings:
- Gearbox Grease Replacement under 20kg High Inertia (Forced Pressure Release Process): The FD11-A20 frequently carries complex heavy fixtures at high speeds, generating extremely high frictional heat inside the heavy-duty cycloidal gearboxes (RV-level structure) of the J1-J3 axes. When injecting the dedicated
100-0127grease, you must simultaneously open the lower inlet and outlet ports, and let the robot run continuously without load at low speed for 25 minutes after injection to execute a “thorough pressure release”. If the oil plug is forcibly sealed while high-pressure gas remains inside, the violently expanding air pressure during operation will instantly burst the elastic oil seal inside the servo motor, causing massive grease backflow into the motor coils and directly burning out the entire motor. - Live Hot-Swap Red Line for 3-Cell Absolute Battery Pack (W-L02722): The No. ⑲ 3-cell large-capacity battery pack is responsible for maintaining the spatial zero coordinates of the absolute encoders for each axis. Whenever replacing this battery, never unplug the old battery connector while the main power to the control cabinet is disconnected! Once unplugged in a powered-off state, because there are no internal capacitors to sustain it, the robot’s 6 axes will completely lose all mechanical zero points within a second, causing all original machining programs to fail due to coordinate disorder. The correct procedure is: keep the entire machine powered on (screen normally lit) for live hot-swapping, and complete the physical replacement within 10 minutes.
- J5 / J6 Timing Belt Tension Frequency Measurement: Wrist pitch and flange rotation (J5/J6 axes) rely on original factory timing belts (
W-L02028/W-L02029) for driving. Because the 20kg model has large terminal inertia, the belts are prone to slight fatigue elongation under long-term high-frequency movements, causing micro trajectory drift in the end welding or cutting torch. When tightening during routine maintenance or replacing with new belts, never rely solely on experience to press them; a professional sonic tension meter must be used to strictly measure their Hz frequency, precisely locking them within the tension bandwidth specified in the original factory maintenance manual. Being too loose easily leads to tooth jumping, while being too tight easily cracks the spindle.
🛠️ Get Real-Time Quotes for FD11-A20 Robot Joint Motors, Precision Gearboxes & Cables
The precision of a heavy-payload industrial robot’s “electromechanical transmission system” directly determines the yield rate of continuous automated trajectory operations. Simply provide your required official part numbers (e.g., W-L02152 Motor, W-L02722 3-Cell Battery, K5439 series wire feed consumables, etc.), and our spare parts system will quickly match and output an authentic factory-price quote for you. Whether you need consumables for various maintenance cycles or highly flexible long-axis internal cable assemblies for complete overhauls, feel free to contact us anytime:


