Views: 0 Author: Site Editor Publish Time: 2026-03-11 Origin: Site
In modern industrial production, the rotary joint serves as a crucial component for connecting fixed pipelines with rotating equipment, and is responsible for transporting various fluid media. Whether it is a CNC machine, packaging machinery, or heavy engineering equipment, none of them can do without this "joint"-like precision component. When faced with a wide variety of rotary joints on the market, how can you choose the most suitable product for your equipment? This article will guide you to understand the basic classification of rotary joints and focus on introducing the selection key points of multi-path rotary joints.
I. Basic Classification of Rotating Connectors
Rotating connectors can generally be classified into three types based on the number of pathways:
Single-path rotary joint
The single-path rotary joint is the "basic model" in the family of rotary joints, only supporting the flow of a single medium, which can be water, gas or oil. From the perspective of the flow direction, it can achieve unidirectional transmission as well as bidirectional circulation. The cooling system of ordinary lathes and the pneumatic control part of small winding equipment all rely on single-path rotary joints to transmit the medium.
Dual-Path Rotary Joint
The dual-path rotary joint enables the independent transmission of two different media. This feature plays a crucial role in certain industries. Take the paper drying cylinder as an example. During the paper drying process, steam needs to be introduced on one side to provide heat, while the other side needs to discharge the condensate. The dual-path rotary joint can perfectly handle this task.
Multi-path Rotary Joint
A multi-path rotary joint refers to a type of rotary joint that has three or more pathways and is capable of simultaneously introducing or outputting one or more types of media. This product integrates multiple channels such as hydraulic and pneumatic, and can achieve the synchronous transmission of various types of media in the same equipment. It is an ideal choice for modern complex working conditions.
II. Application Scenarios of Multi-Path Rotating Connectors
Multi-path rotating connectors are suitable for complex working conditions where multiple media need to be transmitted simultaneously. Here are several typical application fields:
Industrial machine processing center: The rotating table of the processing center needs to simultaneously convey hydraulic oil, coolant, and compressed air. Multi-path rotary joints can achieve the supply of multiple media on a single device.
Rotating worktable: For the worktable of heavy equipment, during the rotation process, continuous supply of hydraulic power and control signals is required.
Construction machinery: The rotating mechanisms of equipment such as hydraulic excavators and cranes need to transfer hydraulic oil while in rotation.
Wind power generation equipment: The relative rotation between the nacelle and the tower cylinder requires the transmission of various media such as hydraulic oil and lubricating oil.
III. Key Points for Selecting Multi-Path Rotating Connectors
To assist you in making an accurate selection of multi-path rotary joints, we have summarized the following five core selection steps:
Determine the number of channels and the type of medium
Firstly, you need to clarify how many types of media the equipment needs to transmit simultaneously. The number of channels usually ranges from 2 to 12, with common options including 2, 3, 4, 6, and 8 channels. At the same time, you need to confirm the type of medium, such as hydraulic oil, coolant, water, steam, air, etc., and pay attention to the compatibility between different media to prevent cross-contamination.
Verify key performance parameters
Pressure and rotational speed are the two most important parameters, and they are often mutually exclusive - the maximum working pressure allowed at high rotational speed will decrease. For example, for certain series, the maximum working pressure can reach 30 MPa when the rotational speed is below 10 RPM, but when the rotational speed increases, the allowed pressure needs to be adjusted accordingly. Additionally, you need to confirm the working temperature range of the medium to ensure it is within the tolerance range of the connection (such as -30℃ to 120℃).
Determine interface size and connection method
Based on the required medium flow rate, determine the diameter size of the interface (such as 1/4 inch, 1/2 inch, etc.). At the same time, it is necessary to clarify whether the connection between the joint and the equipment is by flange or by thread, and whether the inner tube is of the rotating type or the fixed type.
Consider the installation space and working environment
Does the shaft diameter of the rotating equipment and the installation space have any special restrictions? Are there any requirements for hollow holes? Is there any corrosive environment in the working environment and are there any explosion-proof requirements? All these factors affect the selection of the shell material. Common materials include aluminum alloy, steel, stainless steel, and brass.
Pay attention to the quality and service life of the sealing components
The sealing components are the core part of the rotary joint. For different grades of rotary joints, the material and service life of the sealing components vary significantly: for general-grade products, the maximum rotational speed is approximately 100 RPM, and the service life is about 6 million rotations; while for industrial-grade products, the rotational speed can reach 300 RPM, and the service life can reach 20 million rotations, using imported sealing components.
IV. General Principles for Selecting Rotating Connectors
Apart from the specific considerations for multi-path rotating connectors, the following general principles should also be followed during the selection process:
Clarify equipment requirements: Understand which type of rotary joint your equipment uses, what medium it is transporting, what is the import size, and what are the pressure, speed and temperature values.
Parameter maximum value ≠ recommended value: The pressure, speed and temperature indicated in the product manual are usually the maximum limits and cannot be used simultaneously. When making an actual selection, it is recommended to leave an appropriate margin of safety.
Select reliable suppliers: Examine the production qualifications, industry experience and after-sales service capabilities of the manufacturers to ensure that timely support can be obtained in case of any problems.
V. Installation and Maintenance Precautions
Proper installation and maintenance directly affect the service life of the rotary joint:
Pre-installation cleaning: Before installing the rotary joint, please remove any hard particles and other dirt from the pipes and the interior of the joint. The filtration accuracy is recommended to be no less than 10μm.
Using hose connection: A hose (preferably a metal hose) must be used to connect the rotary joint to the pipeline. Rigid connections are strictly prohibited to absorb vibrations and installation errors.
Ensure anti-turning fixation: Since the rotating joint will generate torque during rotation, a stopper rod or stopper plate must be installed to prevent the housing from rotating.
Regular maintenance: For those with an oiling device, please perform regular oiling to ensure reliable operation of the bearings; inspect the wear condition of the sealing surfaces and handle any leakage promptly.
Conclusion
The rotary joint, as the "arterial hub" of industrial fluid systems, is a core component that ensures production efficiency and safety and environmental protection. From the simple single-path joint to the powerful multi-path joint, the evolution of product technology reflects the continuous improvement of industrial manufacturing levels. When selecting, it is recommended that you choose the appropriate product based on specific working condition parameters (medium, pressure, temperature, rotational speed, etc.). Shandong Focus Machinery Co., Ltd. is the manufacturer of rotary joints and is a high-tech enterprise specializing in the research and production of rotary joints. The warranty period is one year. If there is leakage within one year, the internal sealing parts will be provided free of charge. The warranty period is one year. If there is leakage within one year, the internal sealing parts will be provided free of charge.
