In the realm of motion control systems, reliability stands as a cornerstone for optimal performance and longevity. A critical component often susceptible to failure is cabling, making integrated designs inherently advantageous. ClearPath Servo Motors And Drives exemplify this principle, significantly minimizing cabling complexities by integrating the motor, encoder, drive, and controller into a unified system. This design not only reduces potential points of failure but also enhances the overall ruggedness of the system. Beyond integration, ClearPath incorporates numerous design features meticulously engineered to elevate quality and reliability across every facet of its operation. This commitment to excellence allows for the provision of an industry-leading warranty, underscoring the confidence in the durability and dependability of ClearPath products.
Motor Design for Superior Reliability
Every element within ClearPath servo motors is carefully selected and engineered, utilizing premium materials and advanced manufacturing techniques to ensure lasting performance.
From fully sintered rare-earth magnets to Class H temperature-rated wire insulation and permanently sealed, extra-large bearings, no detail is overlooked. The motors feature anodized or electrophoretically-coated finishes, eschewing less durable painted or raw surfaces. The internal construction showcases a dedication to quality, contributing to the enhanced reliability ClearPath is known for.
Pressed and Laced End Turns Enhance Thermal Performance and Quiet Operation
Winding end-turns in ClearPath motors are tightly pressed and laced, creating a dense copper mass that significantly improves thermal performance. This robust construction minimizes wire vibration during current changes, resulting in quieter operation and preventing insulation abrasion and failure over time.
Powerful Rare-Earth Magnets Maximize Motor Performance
ClearPath servo motors utilize sintered neodymium iron boron (NdFeB) magnets, formed into solid bricks, in contrast to “bonded” magnets which mix NdFeB powder with plastic resin. Sintered magnets offer superior power density, providing approximately four times the power of similarly sized AC induction motors that rely on electromagnets.
Precision Machined Shafts Withstand Higher Side Loads
The shaft design in ClearPath servo motors incorporates a smoothly radiused diameter transition. This feature mitigates internal stress concentrations that are common in motor shafts with abrupt diameter changes, thereby preventing shaft breakage under side-loading conditions and improving overall reliability.
Overlapping Coils for Enhanced Smoothness and Power Delivery
ClearPath servo motor stators employ an advanced overlapping, alternate-slot fill pattern with two coil sections per slot, unlike simpler one-coil-per-tooth stators. This sophisticated design minimizes torque ripple, cogging, and detent torque, leading to improved electrical responsiveness and increased power output for smoother and more efficient servo operation.
Compression-Fit Housing Facilitates Effective Motor Cooling
The aluminum housing of ClearPath servo motors features a compression fit around the stator, providing an efficient heat transfer pathway. This design allows heat to be conducted away from the motor and into the mounting surface, which typically acts as a heat sink. Effective heat dissipation increases continuous power output capabilities and enhances the long-term reliability of the servo motor.
Individually Custom-Balanced Rotors Minimize Vibration and Fatigue
Each ClearPath rotor is individually balanced using custom-made brass weights, offering greater precision and security compared to common balancing putty. The brass weights are securely held captive by the shaft, preventing them from detaching, a common issue with balancing putty, thus reducing vibration and extending component life.
Precision Fit Components and Optional Shaft Seal for Environmental Protection
Beyond the inherent protection of ClearPath’s tight mechanical design, an optional dynamic shaft seal is available for added defense against dust and water splashes. This high-quality shaft seal features spring tension, a Viton® lip for minimal compression set and high temperature resistance, a PTFE coating for low friction and wear, and a metal outer case with a Viton® outer coating for enhanced structural rigidity and sealing performance.
Drive and Motor Protection Features
While robust design and construction contribute to longevity, ClearPath servo motors also incorporate protective features to prevent damage from common operational mishaps. These safeguards are designed to protect against issues such as reversed wiring, short circuits, voltage overloads, and mechanical jams, ensuring resilience in demanding applications.
ClearPath servo drives include comprehensive protection mechanisms:
- Input Protection: Control inputs are optically isolated and protected against reverse polarity wiring and overvoltage conditions up to 30V DC.
- Output Protection: Digital outputs are designed to withstand sustained or repetitive short circuits and accidental reverse polarity wiring (up to 1 amp reverse current).
- Operational Protection: ClearPath servo motors safeguard against various operational issues:
- A built-in thermal sensor maintains safe operating temperatures for electronics and motor windings, ensuring they remain well below their 200ºC rating.
- Protective shutdown is triggered if the motor cannot accurately follow motion commands, such as in the event of mechanical jams or excessive speed settings.
- In cases of average torque load exceeding motor capability, ClearPath will safely shut down to prevent motor burnout.
In all shutdown scenarios, ClearPath servo drives employ dynamic braking to bring moving loads to a controlled stop, preventing potential mechanical damage compared to systems that freewheel upon shutdown.
Production Quality and Warranty
Every ClearPath servo motor undergoes rigorous in-line and post-production testing to guarantee exceptional quality. Tests include:
- Electromagnetic performance evaluation
- Magnet field strength measurement
- Encoder integrity verification
- Rotor balance assessment
- Commutation sensor accuracy check
- Critical mechanical tolerances inspection
- Insulation system (hipot) testing
- Full functional performance test
- Highly Accelerated Stress Screening (HASS) to exceed published specifications
This comprehensive testing regime ensures each servo motor meets stringent quality standards before leaving the factory.
Unsurpassed Warranty
ClearPath servo motors and drives are backed by a comprehensive three-year warranty, guaranteeing freedom from defects in material and workmanship. This industry-leading warranty reflects the commitment to quality and the confidence in the long-term reliability of ClearPath servo systems, making them a dependable choice for demanding motion control applications.
