Universal Cross Joint Couplings

The universal cross joint coupling is mainly composed of two fork shaped joints and a cross shaft, connected by rolling bearings. Its working principle is based on the Hooke hinge principle, which can achieve equal angular velocity continuous rotation in the presence of an angle between two axes (usually 5 ° -45 °) or non coaxial working conditions. This design enables it to have angular compensation capability of over 25 ° and axial displacement adaptability, effectively solving the problem of shaft misalignment caused by installation errors, shaft load deformation, temperature changes, and other factors.

There are various structural types of cross universal couplings, which can be classified into heavy, medium, light, and small according to the transmitted torque:

1. Cross axis universal joint: The most common types include SWP type (split fork) and SWC type (integral fork). The SWP type is suitable for heavy-duty equipment with a turning diameter of 1200mm, while the SWC type can cover a turning diameter of 1600mm and a torque transmission distance of over 30 meters. It is commonly used in steel rolling machinery and heavy-duty transportation equipment.
   

2. Ball cage universal joint: Compared to cross shaft type, it can provide smoother transmission and is suitable for high-speed applications.
   

3. SWC-BH standard telescopic welding type: adopting an integral fork head design, it has the ability to compensate for 15 ° -25 ° axis bending angles, with a transmission efficiency of up to 98-99.8%, especially suitable for heavy-duty equipment shaft transmission with axial, radial, and angular displacement.
   

4. WSH type sliding bearing type: adopting a sliding bearing structure, there are various models including standard telescopic welding type, long telescopic welding type, etc. The rotation diameter covers 100 to 670mm, and the nominal torque range is 1.25 to 1250kN.

The universal cross joint coupling has several significant advantages:

1. Large angle compensation capability: The axis angle can reach 15 ° -25 ° (SWC type), and the SWP type can reach about 10 °, which can effectively compensate for the axis deviation generated during installation and use.
   

2. High load-bearing capacity: Compared with other types of couplings with the same rotational diameter, it can transmit greater torque, making it particularly suitable for mechanical equipment with limited rotational diameter.
   

3. Efficient transmission: The transmission efficiency can reach 98-99.8%, and the energy-saving effect is significant in high-power transmission.
   

4. Smooth operation: compact and reasonable structure, low noise, small vibration, long service life.
   

5. Convenient maintenance: easy to install and disassemble, most models adopt standardized design, easy to replace and maintain.

When choosing a universal cross joint coupling, the following factors should be considered:

1. Transmission torque size: Select a coupling with appropriate torque capacity according to equipment requirements, and consider possible impact loads.
   

2. Speed range: Different types of couplings have their applicable speed ranges, and for high-speed applications, it is necessary to choose a type with high balance accuracy.
   

3. Two axis relative displacement: Select the appropriate compensation model based on the expected axial, radial, and angular displacement.
   

4. Work environment: Consider the impact of environmental factors such as temperature, humidity, dust, and corrosive media on the coupling material and lubrication.

Special attention should be paid during installation:

1. Ensure that the centerlines of the two welded fork bearing holes in the middle are on the same plane, with a permissible deviation of no more than 1 °
   

2. The spline part should slide freely and the joint rotation should be flexible
   

3. Clean all parts and remove burrs before installation
   

4. Clean the threads and apply special adhesive before tightening the bolts
   

5. During the initial operation (about 200 hours), it is important to focus on checking for loose bolts

Cross universal couplings are widely used in various industrial fields:

1. Metallurgical machinery: equipment such as rolling mills and cooling beds, capable of withstanding high torque and high speed.
   

2. Heavy machinery: Conveyor systems and crushers for mining machinery, transmission systems for construction machinery.
   

3. Petrochemical industry: shaft connections for various pumps and compressors.
   

4. Transportation: locomotive and vehicle transmission system, ship propulsion system.
   

5. Other industries: lifting and transportation machinery, papermaking machinery, rubber machinery, etc.

As a key component in the mechanical transmission system, the performance of the universal cross joint coupling directly affects the reliability and efficiency of the entire equipment operation. The correct selection, installation, and maintenance of cross universal couplings are of great significance for ensuring long-term stable operation of equipment. With the advancement of materials science and manufacturing technology, cross universal couplings will play a more important role in a wider range of fields in the future.