In modern industrial systems, rotary joints play an important role in transferring fluids between stationary pipelines and rotating equipment. Depending on installation method and functional design, different types of rotary joints are used to meet specific application requirements. Among them, embedded rotary joints and hydraulic multi-channel joints are often compared due to their use in complex fluid transmission systems. Although both are designed to enable fluid transfer during rotation, their structure, working principles, and application focus differ significantly.
An embedded rotary joint has its housing inserted into the roller and secured to the shaft end with a split flange. Only the disconnection point is visible externally after impact; the housing is embedded inside the roller and rotates with it, hence the name "embedded rotary joint." The parts of the embedded rotary joint are made of corrosion-resistant materials. This type of rotary joint is suitable for water-based media. Compared to multi-channel rotary joints, embedded rotary joints come in single-channel and double-channel types, each further divided into end-face sealing and outer-diameter sealing structures.
In contrast, hydraulic multi-channel joints are defined primarily by their functional capability rather than their installation position. A hydraulic multi-channel joint is designed to transmit multiple independent hydraulic circuits through a single rotary interface. Each channel operates separately and can carry different pressures or flow rates. These joints are widely used in systems that require simultaneous control of multiple hydraulic functions, such as construction machinery, wind power equipment, injection molding machines, and industrial robots.
From a structural perspective, embedded rotary joints usually focus on compactness and integration. Their internal channels are often limited in number and are carefully arranged to match the geometry of the rotating shaft. Maintenance access can be relatively restricted, as disassembly may require partial dismantling of the equipment. As a result, embedded rotary joints typically emphasize durability and long service intervals to reduce maintenance frequency.
Hydraulic multi-channel joints, on the other hand, prioritize channel independence and sealing reliability. Internally, they contain multiple concentric or parallel flow paths, each equipped with its own sealing system. This allows different hydraulic circuits to operate without interference. Because of the higher complexity, these joints are often larger in size compared with embedded designs, but they provide greater flexibility in system design and hydraulic control.
Another key difference lies in operating conditions. Embedded rotary joints are often used for moderate pressure and speed applications, where stable operation and compact installation are more important than extreme performance. Hydraulic multi-channel joints are commonly designed to handle high pressure, dynamic load changes, and demanding working cycles. Their sealing systems and materials are selected to withstand hydraulic shock, pressure fluctuations, and long-term continuous operation.
In terms of application scenarios, embedded rotary joints are ideal for precision equipment where space saving, structural integration, and aesthetics are important. Hydraulic multi-channel joints are better suited for heavy-duty machinery that requires multiple hydraulic signals or power transmission through rotation. While some designs may combine both concepts, their core design priorities remain different.
In summary, the main differences between embedded rotary joints and hydraulic multi-channel joints lie in installation method, structural focus, functional complexity, operating conditions, and application fields. Embedded rotary joints emphasize compact integration and space efficiency, while hydraulic multi-channel joints focus on multi-circuit hydraulic transmission and high-performance sealing. Understanding these differences helps engineers select the most suitable solution for reliable and efficient fluid transfer in rotating systems.