I. Components of a Parallel Robot
A parallel robot (also known as a delta robot or spider robot) consists of the following main components:
| Component Category | Specific Parts |
|---|---|
| Mechanical structure | Base frame (static platform), moving platform (end-effector platform), drive arms (active arms), forearm links (passive arms), spherical joints / ball joints, universal joints |
| Drive & actuation | Servo motors (one per arm), servo drives / amplifiers, precision reducers / gearboxes (low-backlash, e.g., harmonic or planetary) |
| End-effector / tooling | Tool mounting flange, suction cups / vacuum grippers, pneumatic or electric grippers, vacuum generator (venturi), custom fingers / jaws |
| Control & sensing | Motion controller (runs inverse kinematics), teach pendant / programming interface, encoders (position/velocity feedback), vision system (camera + processor) (optional), part presence sensors |
| Electrical & auxiliary | Electrical control cabinet (houses controller, drives, PLC, power supplies), cable & hose management (cable carriers, connectors), safety equipment (light curtains, E-stops, fencing) |
II. How Often Should Components Be Replaced?
Replacement intervals depend on operating hours, load, environment, and maintenance quality. The following are typical guidelines for a parallel robot operating 2 shifts (16 hours/day) under normal conditions:
| Component | Typical Replacement Interval | Примітки |
|---|---|---|
| Spherical joints (ball joints) | 8,000 – 12,000 hours (~1.5 – 2.5 years) | Most wear‑prone part; inspect every 3–6 months for play. |
| Forearm links (passive arms) | Only replace if damaged (crack, bend) | Carbon fiber arms are durable unless impacted. |
| Synchronous belts (if used) | 10,000 – 15,000 hours (~2 – 3 years) | Inspect for cracks, wear, or loosening. |
| Servo motors | 30,000 – 50,000 hours (~5 – 8 years) | Replace bearings if noisy; motors often last the robot’s life. |
| Gearboxes / reducers | 15,000 – 25,000 hours (~3 – 5 years) | Backlash increases over time; replace when positioning accuracy degrades. |
| Vacuum cups / suction pads | 3 – 12 months | Depends on part abrasiveness and oil exposure; inspect weekly. |
| Gripper jaws / fingers | 6 – 24 months | Wear from friction with parts; replace when grip becomes unreliable. |
| Encoders | Rarely replaced (often with motor) | Failure is uncommon; replace only if faulty. |
| Cables (motor power, encoder, air tubing) | 15,000 – 25,000 hours (~3 – 5 years) | Flexing cables in cable carrier wear over time; inspect for cracks. |
| Springs (if used in end-effector) | 500,000 – 1,000,000 cycles (~1 – 3 years) | Replace when spring force weakens or when part drops. |
| Main controller battery (for memory backup) | 1 – 3 years (or per manufacturer) | Replace before battery low alarm to avoid losing parameters. |
III. Factors That Shorten Replacement Intervals
| Factor | Effect |
|---|---|
| Heavy payload (near max capacity) | Accelerates wear on joints, motors, and gearboxes. |
| High acceleration / cycle rate | Increases stress on spherical joints and belts. |
| Dusty or abrasive environment | Wears joints and bearings faster. |
| Corrosive atmosphere (chemicals, moisture) | Reduces life of metal parts and bearings. |
| Poor lubrication (if applicable) | Increases friction and wear. |
| Insufficient maintenance (no cleaning/inspection) | Leads to unexpected failures. |
IV. Recommended Maintenance Schedule
| Частота | Actions |
|---|---|
| Daily / per shift | Visual inspection; clean end‑effector; check for loose screws. |
| Weekly | Check spherical joints for play; inspect belts for tension; clean sensor lenses. |
| Monthly | Grease / lubricate moving joints (follow manufacturer spec); check cable carrier for wear. |
| Quarterly | Measure backlash in gearboxes; check motor temperature; verify positioning repeatability. |
| Yearly | Replace worn vacuum cups; replace battery in controller; perform full system calibration. |
V. Summary Table (Quick Reference)
| Component | Typical Life | When to Replace |
|---|---|---|
| Spherical joints | 8k–12k hours | Play, looseness, or noise |
| Synchronous belts | 10k–15k hours | Cracks, wear, slipping |
| Gearboxes | 15k–25k hours | Backlash > spec |
| Servo motors | 30k–50k hours | Bearing noise, encoder failure |
| Vacuum cups | 3–12 months | Hardened, cracked, or poor suction |
| Cables | 15k–25k hours | Cracked insulation, intermittent signals |
| Controller battery | 1–3 years | Low battery alarm |

