RSK-WS Precision Universal shaft Double type Large-Angle Torque Transmission

Large-Angle Torque Transmission Capability

Outstanding Heavy-Load Capacity

Strong Combined Misalignment Compensation

High Transmission Efficiency

A Precision Universal shaft  (U-joint) is a high-quality mechanical coupling that transmits rotational power between non-aligned shafts, allowing for movement and varying angles, commonly used in vehicles and machinery for smooth, reliable torque transfer where straight connections aren't possible, featuring tight tolerances, durable materials (like hardened alloy steel with needle bearings), and advanced sealing for long life and consistent performance, unlike standard U-joints that might have speed variations at high angles. 

Key Characteristics

Angle Compensation: Connects shafts at intersecting, non-parallel angles, crucial for suspensions or machinery articulation.

High Precision: Manufactured to strict tolerances for smooth operation, minimizing vibrations and power loss, notes Partsource and Belden Universal.

Durable Components: Uses hardened alloy steel crosses, heat-treated needle bearings, and robust seals for enhanced strength and lubrication distribution, explains Partsource and Belden Universal.

Corrosion Protection: Often features protective coatings (like MICRO SHIELD™) for rust resistance, adds Partsource

How it Works (Basic U-Joint)

Structure: An X-shaped pivot (cross) connects two yokes (one on each shaft).

Motion: The cross allows the shafts to pivot, transmitting rotation even when angled, like a gimbal.

Potential Speed Fluctuation: A single U-joint can cause the output shaft to speed up and slow down (non-constant velocity) if the angle is significant, notes Wikipedia and WM Berg.

Precision Solution: Precision joints minimize this fluctuation, ensuring smoother power delivery compared to standard ones, especially in critical applications

Common Applications

Automotive: Driveshafts in rear-wheel-drive (RWD) and four-wheel-drive (4WD) vehicles, connecting transmission to differentials.

Industrial Machinery: Connecting rotating parts in automation, robotics, and other heavy equipment where angles change

The RSK-WS type coupling typically features a double universal joint arrangement to achieve constant or near-constant velocity transmission. Its main components include:

Two Cross Shaft Assemblies: The core components. Each assembly consists of:

Cross Shaft (Spider): Forged from high-strength alloy steel, it is the main load-bearing component

Needle Roller Bearings: Installed on the four journals of the cross shaft to reduce friction

Bearing Caps / Seals: Secure the bearings and provide protection against dust and water

Two Yokes (Flange Yokes or Weld Yokes): Connect to the cross shaft assemblies

One Intermediate Shaft (Drive Shaft): Connects the yokes at both ends via splines or flanges

Spline Sliding Sleeve (Slip Tube): A defining feature of the RSK-WS type. The intermediate shaft is usually designed with external splines that engage with an internal splined sliding sleeve. This allows the drive shaft to slide axially while transmitting torque, compensating for axial displacement caused by thermal expansion/contraction or installation.

Sliding Bearings or Lubrication Fittings (Grease Nipples): Ensure lubrication of the spline assembly.

 Key Characteristics:

1.Large-Angle Torque Transmission Capability:

A single joint can achieve a working angle of 15° - 25° or even more, suitable for connecting equipment with non-collinear axes or equipment whose working position changes.

2.Outstanding Heavy-Load Capacity:

Utilizes high-strength alloy steel and large-sized needle roller bearings. Its robust construction makes it one of the most reliable mechanical solutions for transmitting extremely high torque (up to millions of Newton-meters). Widely used in metallurgical rolling mills, mining machinery, etc.

3.Strong Combined Misalignment Compensation:

Angular Compensation: Achieved via the cross shaft articulation.

Axial Compensation: Achieves large-distance axial movement (up to several hundred millimeters) through the spline sliding sleeve, a key advantage of the WS type.

Radial Compensation: Possesses a degree of adaptability.

4.High Transmission Efficiency:

Reliable Structure, Long Service Life:

Mature design with all load-bearing parts being metallic. Offers a long service life when properly maintained.

Primary Application Fields

The WS type is a classic "Mainstay of Heavy Industry" coupling, suitable for:

Metallurgical Industry: Main and auxiliary drives for steel rolling mills (blooming mills, section mills, plate mills).

Lifting and Transportation: Boom luffing mechanisms of large port pedestal cranes, ship loaders/unloaders.

Mining Machinery: Drive systems for excavators, crushers, ball mills.

Construction Machinery: Drive sections of large crawler cranes, tunnel boring machines.

Paper Machinery, Marine Deck Machinery, and other applications requiring large-angle, high-torque transmission.