OTC DAIHEN FD-B6L Extended-Arm Through-Arm Robot Mechanical Structure & Core Parts Analysis
In the OTC DAIHEN automated welding equipment line, the FD-B6L is a highly technical special industrial robot. It combines two major features: a 2.0-meter ultra-long working radius and coaxial cable through-arm (hollow routing) design. Not only can it reach deep inside large box structures for welding, but it also completely prevents interference between the external welding torch cable and the workpiece during long-arm operations. Its lower base (J1-J3 axes) utilizes high-strength RV gearboxes to withstand the massive overturning moment caused by the extended lever arm, while the wrist section (J4-J6 axes) integrates hollow harmonic gearboxes and a dedicated inner ring guide assembly for the cables.
This extreme structure poses the highest requirements for assembly and maintenance precision. When performing routine overhauls (such as replenishing 100-0624 cycloidal grease, reapplying the exclusive 100-0942 liquid gasket, or extracting/replacing the L11751D00 long-axis communication cable), please strictly follow the official factory exploded view and the parts list for each axis below. Never use the wrong grease or blindly disassemble the wrist by force:
📷 Figure 1: OTC DAIHEN FD-B6L Industrial Robot Complete Mechanical Parts Configuration Diagram
2. FD-B6L Core Parts Reference Table by Axis
For the convenience of the workshop equipment department, we have consolidated the power units, reduction units, and special cable accessories of the J1 to J6 axes into a comprehensive global matrix table. Please carefully cross-reference the circled numbers (①-⑲) in Figure 1:
| Axis / Location | Image Ref. | Official Part Number | Standard Part Name | Function & Maintenance Notes |
|---|---|---|---|---|
| J1 Axis (Rotating Base) |
① | W-L02788 | AC Servomotor | Provides main power for wide-range horizontal base rotation. |
| ② | W-L02116 | Cycloidal/RV Gearbox | High-rigidity, large-capacity base main reducer. | |
| ③ | 100-0624 | Lubricating Grease | Liquid anti-friction grease dedicated for RV gearboxes. | |
| J2 Axis (Lower Arm Pitch) |
④ | W-L02152 | AC Servomotor | Provides high-torque main power for lower arm forward/backward pitch. |
| ⑤ | W-L02117 | Cycloidal/RV Gearbox | Core reducer bearing the extreme gravity overturning moment of the 2.0m extended arm. | |
| ③ | 100-0624 | Lubricating Grease | Liquid anti-friction grease dedicated for RV gearboxes. | |
| J3 Axis (Upper Arm Pitch) |
① | W-L02788 | AC Servomotor | Provides main power for upper arm up/down pitch (same as J1 motor). |
| ⑥ | L10725F00 | Cycloidal/RV Gearbox | Heavy-duty reducer driving the extension of the upper arm. | |
| ③ | 100-0624 | Lubricating Grease | Liquid anti-friction grease dedicated for RV gearboxes. | |
| J4 Axis (Arm Rotation) |
⑦ | W-L02789 | AC Servomotor | Provides main power for arm axial rotation. |
| ⑧ | W-L02784 | Harmonic Gearbox | Hollow through-cable harmonic reducer. | |
| ⑨ | W-L02794 | Timing Belt | First-stage toothed transmission synchronous belt. | |
| ⑩ | L11761N00 | Inner Ring Guide ASSY | Dedicated internal guide kit for through-arm routing to prevent cable shearing. | |
| ⑪ | 2670-052 | Lubricating Grease | Flexible high-viscosity lubricating grease dedicated for harmonic gearboxes. | |
| ⑫ | 100-1491 | Lubricating Grease | Dedicated anti-friction grease for local contact surfaces or gear cavities. | |
| J5 Axis (Wrist Pitch) |
⑬ | W-L02790 | AC Servomotor | High-speed motor controlling the up/down pitch of the wrist. |
| ⑭ | L11700Y00 | Harmonic Gearbox | High-precision hollow harmonic reducer for the wrist. | |
| ⑮ | W-L02801 | Timing Belt (J5) | Dedicated toothed transmission belt for wrist pitch mechanism. | |
| ⑯ | 100-0942 | Liquid Gasket | Original factory liquid silicone for sealing end covers against oil leakage. | |
| ⑪ | 2670-052 | Lubricating Grease | Dedicated flexspline lubricating grease for harmonic gearboxes. | |
| ⑫ | 100-1491 | Lubricating Grease | Specified anti-friction oil for contact surface replenishment. | |
| J6 Axis (Flange Rotation) |
⑬ | W-L02790 | AC Servomotor | Controls the high-torque, high-speed rotation of the end flange. |
| ⑰ | L11700L00 | Harmonic Gearbox | Zero-backlash hollow harmonic drive for end flange. | |
| ⑱ | W-L02802 | Timing Belt (J6) | End axis high-speed rotation synchronous toothed transmission belt. | |
| ⑪ | 100-1516 | Sealant | Original factory high-temperature anaerobic sealant to prevent end cover leakage. | |
| ⑫ | 2670-053 | Lubricating Grease | Dedicated anti-friction grease for end high-frequency friction pair. | |
| Cables & Accessories (Global) |
— | L11751D00 | Cable Assembly (1) | Highly flexible main axis cable from the rear of the rack to the upper end of the extended arm. |
| — | L11761D00 | Cable Assembly (2) | Dedicated flying leads for J5 and J6 axis motors communication inside the upper arm. | |
| — | L11761E00 | Cable Assembly (3) | Auxiliary flexible cables for J5 and J6 axes inside the upper arm. | |
| — | L11700B00 | J5, J6 Axis Unit Assembly | Hollow mechanical housing assembly for the wrist. | |
| — | L10485Q00 | Power Cable Assembly 1 | High-voltage servo power supply line inside J1 axis. | |
| — | L10485S00 | Power Cable Assembly 2 | Servo main power supply long line from J2 to the upper arm. | |
| ⑲ | W-L01399 | Battery (Encoder) | Backup lithium battery pack maintaining the mechanical zero coordinates of the encoders. |
* Note: Items with an “Image Ref.” of “—” in the table represent wiring harness kits or assemblies hidden inside the main body, which cannot be visually indicated in the external skeleton exploded view. Please perform overall disassembly and replacement according to the original factory manual.
💡 FD-B6L 2.0m Extended Through-Arm Robot Overhaul & Maintenance Red Card Warnings:
- Gearbox Grease Replacement Under Ultra-Long Lever Arm (Forced Pressure Release to Prevent Oil Burst): The B6L model has a lever arm of 2.0 meters, and the cycloidal gearboxes of its base and lower arm endure massive leverage torque, easily accumulating high temperature and high pressure inside the cavity. When injecting new grease (e.g., 100-0624) into the J1-J3 axes, you must absolutely open both the inlet and outlet ports simultaneously, and let each axis of the robot run continuously without load at 20%-30% low speed for 30 minutes after injection to thoroughly “release pressure”. If the oil plug is forcibly sealed without fully exhausting the high-pressure air inside the cavity, the rapidly expanding air will instantly burst the servo motor’s internal skeleton oil seal, causing massive grease backflow and completely burning out the motor coils.
- Through-Arm Cable Interference & Inner Ring Guide (L11761N00) Fragmentation: As a through-arm model, the thick welding torch coaxial cable must pass through the hollow cavity of the J4 axis. If the twist angle is set improperly when extracting and replacing the wire feed hose, the robot will fatally pull the internal cable during large-angle deflections, instantly shredding the extremely fragile Inner Ring Guide ASSY (L11761N00). Once this part breaks, metal debris will fall directly into the harmonic gearbox flexspline, causing the high-value core assembly to be ruined.
- J5 Liquid Gasket (100-0942) Application Taboos: The joint surface of the J5 axis gearbox uses an extremely high-standard
100-0942liquid gasket. When disassembling and reassembling, the use of off-brand silicone as a substitute or excessive application is strictly prohibited. Squeezed-out residual glue will directly contaminate the adjacent timing belt (W-L02801), causing severe slipping during high-speed swings and emergency stops of the extended arm, directly triggering permanent deviation of the welding torch TCP (Tool Center Point). - Encoder Battery (W-L01399) Live Hot-Swap Rule: The No. ⑲ battery located inside the base maintains the spatial absolute coordinate memory of the 6 axes. Never unplug the old battery connector while the main power to the control cabinet is disconnected! When replacing the
W-L01399battery, the control cabinet must remain powered on, and the new battery must be rapidly plugged in immediately after removing the old one.
🛠️ Get Real-Time Quotes for FD-B6L Robot Motors, Gearboxes & Through-Arm Cables
The health of an extended through-arm robot’s “skeleton, transmission, and sealing system” directly determines the safety of deep cavity machining and weld seam precision. Simply provide the required official part numbers (e.g., W-L02788 Motor, L11761N00 Guide, W-L01399 Battery), and our automated spare parts system will quickly match and output an accurate, ready-to-ship quote for you. Whether you need original factory liquid sealant for routine maintenance or long-axis communication internal lines dedicated for a wrist overhaul, feel free to contact us directly: