OTC DAIHEN FD-V8L Extended-Arm Robot Mechanical Structure & Core Parts Analysis
In the OTC DAIHEN automated welding product line, the FD-V8L is a special industrial robot featuring a 2.0-meter ultra-long reach and external cable routing architecture. Compared to the standard arm, its ultra-long forward reach greatly expands the processing envelope, making it ideal for deep cavity welding of large construction machinery, automotive chassis, or complex box structures. To resist the extreme physical overturning moment caused by the long lever arm, its lower base (J1-J3 axes) utilizes high-rigidity cycloidal gearboxes (RV gearboxes); while the wrist (J4-J6 axes) integrates compact harmonic gearboxes and high-load crossed roller bearings.
An extended reach means the torque borne by the gearboxes is much more severe, and the transmission belts are more prone to fatigue stretching. When performing routine robot overhauls (such as replacing cycloidal gearbox grease, calibrating belt tension, or extracting/replacing the L11751B00 internal highly flexible cable), please strictly follow the official factory exploded view and the parts list for each axis below. Never mix different models of grease or motors:
📷 Figure 1: OTC DAIHEN FD-V8L Extended-Arm Industrial Robot Complete Mechanical Exploded View
2. FD-V8L Core Parts Reference Table by Axis
For the convenience of the workshop equipment department, we have consolidated the power units, reduction units, and cable accessories of the J1 to J6 axes from scattered tables into a comprehensive global matrix table. Please carefully cross-reference the circled numbers (①-⑱) 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 Gearbox | High-rigidity, large-capacity base main reducer. | |
| ③ | 100-0624 | Lubricating Grease | Liquid anti-friction grease dedicated for cycloidal/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 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 cycloidal/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 | L10725F | Cycloidal Gearbox | Heavy-duty reducer driving the extension of the upper arm. | |
| ③ | 100-0624 | Lubricating Grease | Liquid anti-friction grease dedicated for cycloidal/RV gearboxes. | |
| J4 Axis (Arm Rotation) |
⑦ | W-L02151 | AC Servomotor | Provides main power for arm axial rotation. |
| ⑧ | W-L02113 | Harmonic Gearbox | Compact flexspline harmonic reducer. | |
| ⑨ | W-L02551 | Crossed Roller Bearing | Precision rotary bearing carrying lateral turnover and dynamic torque. | |
| ⑩ | 2670-053 | Lubricating Grease | Flexible high-viscosity lubricating grease dedicated for harmonic gearboxes. | |
| ⑪ | 100-1491 | Lubricating Grease | Supplemental grease for crossed roller bearing and local gear cavities. | |
| J5 Axis (Wrist Pitch) |
⑫ | W-L02148 | AC Servomotor | Controls the up/down pitch angle of the welding torch. |
| ⑬ | W-L01949 | Harmonic Gearbox | High-precision harmonic reducer for the wrist. | |
| ⑭ | W-L01945 | Timing Belt (J5) | Toothed transmission synchronous belt connecting motor and gearbox. | |
| ⑮ | 100-1516 | Sealant | Original factory high-temperature anaerobic sealant for leakage prevention. | |
| ⑩ | 2670-053 | Lubricating Grease | Dedicated flexspline lubricating grease for harmonic gearboxes. | |
| J6 Axis (Flange Rotation) |
⑫ | W-L02148 | AC Servomotor | Controls the high-torque, high-speed rotation of the end welding torch flange. |
| ⑯ | W-L02270 | Harmonic Gearbox | Zero-backlash harmonic drive for end flange. | |
| ⑰ | W-L01946 | Timing Belt (J6) | End axis synchronous toothed transmission belt. | |
| ⑮ | 100-1516 | Sealant | Anti-oil leakage sealant for end cover. | |
| ⑩ | 2670-053 | Lubricating Grease | Dedicated anti-friction grease for end high-frequency friction pair. | |
| Cables & Accessories (Global) |
— | L11751B00 | Cable Assembly (1) | Highly flexible main axis wiring harness assembly from the rear of the rack to the upper arm. |
| — | L11751D00 | Cable Assembly (2) | Dedicated flying leads for J5 and J6 axis communication inside the upper arm. | |
| — | L10460B00 | J5, J6 Axis Unit Assembly | Wrist mechanical housing and power train comprehensive assembly. | |
| ⑱ | 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-V8L Extended-Arm Robot Overhaul & Maintenance Red Card Warnings:
- Extended-Arm Model Gearbox Grease Replacement (Forced Pressure Release to Prevent Oil Burst): Because the V8L model has a lever arm extended to 2.0 meters, the cycloidal gearboxes of its base and lower arm (J1-J3 axes) endure physical leverage torque far exceeding standard models, easily accumulating high temperature and high pressure inside the cavity during operation. When injecting new grease (e.g., 100-0624), you must absolutely open both the inlet and outlet ports simultaneously, and let each axis of the robot run continuously without load at 30% low speed for 20-30 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.
- Long-Arm End “Whiplash Effect” & J5/J6 Axis Belt Abnormal Fatigue: When a long-arm robot executes high-speed emergency stops over large spans between points, the front end will generate a slight vibration margin (whiplash effect). This external force will react directly on the timing belts of the J5/J6 axes (
W-L01945/W-L01946). When replacing belts during maintenance, never blindly apply pressure based on feel; a professional sonic tension meter must be used to accurately adjust them to the Hz frequency baseline specified in the official maintenance manual. Being too loose will inevitably lead to tooth jumping and crashes, while being too tight will crush the precision bearings. - Encoder Battery (W-L01399) Live Hot-Swap Rule: The No. ⑱ battery pack located inside the base maintains the spatial absolute position coordinate system of the robot’s 6 axes. Never unplug the old battery connector while the main power to the control cabinet is disconnected! Once unplugged during a power outage, all encoder origin memory will instantly clear to zero. When replacing the
W-L01399battery, the control system must remain powered on, and the new battery must be plugged in immediately after removing the old one.
🛠️ Get Real-Time Quotes for FD-V8L Robot Motors, Gearboxes & Cables
The health of a large extended-arm industrial robot’s “skeleton and muscles” directly determines the safety of the machining process and the precision of the weld seam. Simply provide the required official part numbers (e.g., W-L02788 Motor, L10725F Gearbox, 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 Cycloidal/Harmonic grease for routine maintenance or internal highly flexible cable assemblies for a complete overhaul, feel free to contact us directly: