Structural principle of rotary joint

The structure of a rotary joint consists of three main parts, namely the rotating part, the resting part, and the sealing part. The rotating department is connected to the rotating chamber, and the resting department is connected to the resting chamber, with a complete fluid channel between these two departments;

The sealing department seals the fluid to prevent leakage of fluid channels and mixing between fluids. Therefore, the design requirements for rotary joints should focus on easy processing and manufacturing, small size, light weight, safe and reliable use, easy reversal, and long service life. But a hydraulic system with high filtering accuracy is required, with impurity particle size not exceeding 10um; due to the small amount of open space, high precision requirements are placed on the parts. Ensure that the sealed open space is evenly distributed and not messy. The key components of the rotary joint are the core shaft and the fixed shell. The core shaft is connected to the external expansion and contraction cylinder by bolts and rotates with it. The fixed shell is fixed and does not move, while the core shaft and the fixed shell are ground and free in cooperation, providing a non-contact seal. Pressure oil enters from the working oil port of the housing hole, passes through the sealing surface into the corresponding channel of the core shaft, and finally flows into the oil chamber at one end of the expansion and contraction cylinder, while the pressure oil in the oil chamber at the other end returns to its original port through the other end of the core shaft. Using deep groove ball bearings as connecting components, due to the bearing clearance being smaller than the clearance between the core shaft and the fixed housing, the clearance between the core shaft and the fixed housing is ensured to a certain extent, ensuring that there is clearance between the core shaft and the fixed housing at all times, making the structure of the rotary joint more fair.