A hydraulic rotary union is a device used to convey fluids (such as hydraulic oil, water, coolant, etc.). It is mainly applied to connect fluid passages between stationary pipelines and rotating components, ensuring continuous and leak-free fluid transmission during rotation.
The working principle of a hydraulic rotary union essentially establishes a stable and reliable fluid transfer path between stationary and rotating parts. Its core objective is to prevent hydraulic oil leakage and flow interruption while maintaining the pressure and flow rate required by the system, as its two connected parts (one stationary and one rotating) undergo relative rotation.
- Sealing Principle: Sealing is the "heart" of the rotary union. It consists of a stationary seal ring and a rotating seal ring, which perform sealing and lubrication during rotation. These rings are usually made of high-hardness, wear-resistant materials such as silicon carbide and cemented carbide.
- Rotation and Support Principle: To ensure smooth rotation of the sealing surfaces, a precision support system — bearings — is required. High-quality ball bearings and roller bearings are commonly adopted, undertaking two primary functions: radial support and axial positioning.
- Fluid Passage Principle: Annular oil grooves as well as axial and radial holes are machined inside the rotor and outer housing to keep the fluid passages connected, enabling continuous fluid transfer from stationary pipelines into the interior of the rotating shaft.
In summary, the hydraulic rotary union acts as a rotating bridge for fluids. Through precision mechanical structures (seals, bearings and oil grooves), it ingeniously resolves the conflict between stationary and moving components, allowing hydraulic power to transfer seamlessly across the rotating interface. Its performance directly depends on materials, machining accuracy and design rationality.
Haikun Transmission specializes in manufacturing customized rotary unions, multi-passage rotary unions, hydraulic rotary unions and other related products. Every unit undergoes rigorous pressure, service life and working condition simulation tests before delivery. We have become a trusted partner for many leading enterprises across various industries. We supply not only standard products but also commit to jointly developing innovative solutions with you to meet future challenges.
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