1. Definition and Overview
A Snake Spring Coupling is a type of flexible shaft coupling designed to transmit torque between two shafts while accommodating misalignment and absorbing shock and vibration. Its name derives from its unique, serpentine-like spring element, which is its core functional component. This design offers an exceptional balance of flexibility and torsional rigidity.
2. Primary Function and Purpose
The main purposes of a Snake Spring Coupling are:
Torque Transmission: To efficiently transmit rotational power from a driver shaft (e.g., a motor) to a driven shaft (e.g., a pump or gearbox).
Misalignment Compensation: To accommodate various types of misalignment between connected shafts, including:
Angular Misalignment: Shafts at an angle to each other.
Parallel Misalignment: Shafts with offset but parallel axes.
Axial Misplacement: Shafts moving slightly towards or away from each other during operation.
Vibration Damping: To absorb and dampen torsional vibrations and shock loads, protecting connected equipment from damage.
Electrical Isolation: To provide a degree of electrical insulation between components, preventing circulating currents.
3. Key Components and Design
The coupling typically consists of two main parts:
Two Hubs: Made of aluminum or stainless steel, these are mounted onto the shaft ends (usually via setscrews or clamps). The hubs have lobed profiles on their outer edges.
Snake Spring: A single, continuous, hexagonal-shaped spring steel wire wound into a serpentine pattern. This spring neatly nests into the spaces between the lobes of the two hubs, forming the flexible connection.
4. Advantages and Characteristics
High Flexibility: The spring design allows for significant misalignment capacity.
Zero Backlash: Provides precise positional accuracy and repeatability, making it suitable for motion control applications.
Maintenance-Free: Requires no lubrication and is designed for long service life.
Torsionally Stiff: Offers high torque transmission relative to its size with minimal wind-up, ensuring accurate timing between shafts.
Easy Installation: The "snap-in" design of the spring allows for quick assembly and disassembly without moving the connected machinery.
5. Common Applications
Snake Spring Couplings are widely used in industries requiring precision and reliability, such as:
Motion Control: CNC machines, robotics, servo drives, and automated assembly systems.
General Industrial Machinery: Pumps, compressors, conveyors, and mixers.
Aerospace and Defense: Actuator systems and instrumentation drives.
Printing and Packaging Equipment.
