The Snake Spring Coupling is a highly efficient and versatile mechanical component designed to connect two rotating shafts while accommodating misalignment and reducing vibration. Its name derives from its defining component: a wave-shaped, serpentine spring that provides a unique combination of strength and flexibility. This coupling is not merely a connector but a sophisticated device that manages the complex realities of mechanical power systems, including misalignment, vibration, and shock loads.
Construction
The Snake Spring Coupling consists of two hubs, a center element (snake spring), and a series of spring elements. The hubs are typically made of high-strength steel, machined to provide precise dimensions and surface finish. The center element, also known as the snake spring, is made of a special alloy (often 60Si2MnA alloy spring steel) with excellent flexibility and fatigue resistance. The inner ring of each half-coupling is processed with trapezoidal tooth grooves, and the snake-shaped spring is embedded in these grooves on both sides to form meshing. An outer shell seals the spring and stores lubricating grease to prevent dust from entering.
Working Principle
The coupling operates on a simple yet effective principle: torque is transmitted from the driving hub to the spring element. As the driving hub rotates, its teeth engage with the curves of the snake spring, compressing it. This force is then transmitted through the spring to the teeth of the driven hub, setting it into motion. The spring flexes as it engages and disengages with the lobes of the hubs, transmitting power smoothly while accommodating misalignments.
The snake spring acts as a flexible connection, compensating for three primary types of shaft misalignment:
Angular misalignment: where the shafts meet at an angle
Parallel misalignment: where the shafts are offset but parallel
Axial misalignment: where shafts move slightly inward or outward along their axis
Key Features and Advantages
1. High Misalignment Capacity
The snake spring design enables the coupling to tolerate significant misalignment without compromising performance. It can compensate for axial deviations (≤10mm), radial deviations (≤0.5mm), and angular deviations (≤1.5°).
2. Excellent Vibration Damping
The spring elements absorb and dissipate vibrations, resulting in smoother operations and reduced noise levels. The shock absorption effect is better than that of elastic column pin couplings, and it can absorb more than 50% of vibration impact.
3. High Torque Transmission
The snake spring efficiently transmits torque while providing flexibility and damping capabilities. The transmission torque range is wide (100-1,000,000 N·m), and the transmission efficiency reaches up to 99.47%. The short-term overload capacity is 2-3 times the rated torque, ensuring safe and reliable operation.
4. Compact and Lightweight Design
Snake spring couplings are designed to be lightweight and compact, making them ideal for space-constrained applications. The whole machine has few parts, small size, and light weight.
5. Long Service Life
With proper maintenance, snake spring couplings can have a long service life due to their robust construction and high-quality materials. The spring is designed for high-cycle fatigue resistance, with a lifespan of over 10,000 hours under normal conditions.
6. Simple Installation and Maintenance
The modular design allows for easy assembly and disassembly without needing to move the connected machinery. During disassembly and assembly, there is no need to move the shaft system, making maintenance convenient.
