4462858 Original Excavator back-up ring for EX1900-6

The original support ring part number 4462858 is a key sealing guide component for the hydraulic system of the Hitachi EX1900-6 ultra large hydraulic excavator. It is mainly suitable for models such as EX1900-6, EX1900-6LD, EX1900E-6, etc., and is used for guiding and supporting the piston or piston rod of the boom, stick, bucket cylinder or walking motor to prevent direct contact wear of metal parts. This universal number is its only original factory identification. When ordering, the complete model number, serial number, and hydraulic cylinder identification code of the equipment must be provided to ensure accurate matching of size and material.

This product belongs to high-strength engineering plastic guide rings (support rings), usually made of polyoxymethylene (POM) or phenolic sandwich composite materials, with excellent wear resistance, low friction coefficient, and corrosion resistance. Its working temperature range covers -60 ℃ to 220 ℃, and can withstand pressure ≤ 62 MPa. It is suitable for working media such as hydraulic oil and emulsion. The standard hardness is about 95A ± 5, which has the functions of absorbing radial loads, reducing vibration noise, and dust prevention. The structural design is mostly L-shaped or T-shaped cross-section to adapt to the oil cylinder groove, ensuring stable guidance and sealing protection under EX1900-6 heavy-duty operation.

Regular inspection: Check the support ring for cracks, deformation, or abnormal wear every 500 hours of work, especially when the oil cylinder frequently extends and retracts. Cleaning and lubrication: Thoroughly clean the inner wall and grooves of the oil cylinder during disassembly and maintenance. Before installation, apply an appropriate amount of hydraulic oil or grease on the surface of the support ring to reduce initial friction. Installation precautions: Special tools should be used during installation to avoid violent impacts and ensure that the ring body is flat and embedded in the groove without distortion. Timing of replacement: When the support ring experiences severe wear (thickness reduction of more than 30%), hardening, cracking, or loss of elasticity, it must be replaced in a timely manner. In harsh working conditions such as mines, it is recommended to perform preventive replacement of the support rings of key oil cylinders every 3000-4000 working hours to ensure the sealing and reliability of the hydraulic system.