Hydraulic cylinders are designed to generate longitudinal force and handle the longitudinal load. But many of these cylinders are also impacted severely by the transverse load. The engineering rule of thumb says that about 10-15% of the hydraulic force is always applied as transverse load, even in the most ideal situation.
The mechanical impact of this load can be reduced by using a variety of techniques but radial load still exists and occurs, causing excessive wear of internal guide components (bearing components) in the glands and on the piston heads of the cylinders.
Enter: Hydraulic Wear Rings
The use of internal guiding components or “wear rings” can dramatically reduce the impact of radial load, especially in horizontal and long-stroke applications. These rings can ensure that sliding components of the cylinders are properly supported against radial loads and move properly guided in a longitudinal direction.
A correctly designed bearing system in combination with the proper non-metallic wear ring material can prolong the lifetime of the seal components, improving both the reliability and service life of the cylinders.
The functions of guide components in hydraulic cylinders include:
- Act as a linear (longitudinal) guide for the moving metallic components in the cylinders
- Provide radial support of the metallic components
- Protect seal components against excessive mechanical radial force/load and deformation
- Protect seal components against uneven wear out
- Position moving metallic components in a concentric location, maintaining clearances/radial gaps
- Protect seal components against the radial load-caused momentum
Wear Ring Choices
Traditionally ferrous and non-ferrous metallic guide components were used as bushings for rods/rams and piston heads. The typical ferrous bearing material was gray cast iron (various grades), while non-ferrous was bearing bronze (various grades). However, these guide types have been found to be problematic and costly over the long term.
High-performance non-metallic wear rings such as Chesterton 16K and 17K are the best choice to protect seal components against excessive radial force, mechanical damage, and transverse load momentum in the cylinders.
To learn more about techniques for reducing cylinder load, the benefits of non-metallic bearing bands, and the strength and weaknesses of various bearing band materials, download our free ebook:
Free E-Book: Benefits of Non-Metallic Hydraulic Wear Rings on Heavy Duty Hydraulic Cylinders and Presses
