Numerical values-425-15-19250

Functions and Effects

1. Core Sealing Functions

Hydraulic Pressure Seal: Forms a dynamic seal in the gearbox clutch assembly, preventing high-pressure hydraulic oil leakage and ensuring smooth and reliable shifting.

Cavity Isolation: Separates different pressure chambers in the gearbox, preventing shifting failure or delay caused by oil leakage.

Contamination Prevention: Prevents external impurities from entering the gearbox, protecting precision hydraulic components and bearings.

2. Application Scenarios

Power Shift System: Used for clutch piston sealing in the power shift gearbox of D275/D61/D63 bulldozers.

Hydraulic Control System: Ensures precise hydraulic oil transmission between valve bodies and cylinders, enabling rapid and smooth shifting between gears.

Lubrication System: Prevents lubricating oil leakage, maintains a good lubrication environment inside the gearbox, and reduces friction and wear.

Product Superiority

1. Innovative Structural Design

Three-Layer Composite Structure:

Inner Layer: High-density PTFE (polytetrafluoroethylene) main sealing ring, providing extremely low friction coefficient and excellent wear resistance.

Middle Layer: High-performance NBR rubber elastomer, providing constant preload and sealing compensation.

Outer Layer: Metal support ring, enhancing structural stability and preventing high-pressure deformation.

Floating Seal Design: Allows for slight floating in hydraulic oil, automatically adapting to minor shaft diameter deviations and vibrations, extending service life by over 30%.

Double Sealing Lips: The main lip handles high-pressure sealing, while the secondary lip provides dust and dirt protection, offering double protection.

2. Superior Material Performance

PTFE Main Sealing Layer:

Friction coefficient < 0.05, significantly reducing power loss and improving transmission efficiency.

Temperature range -55℃ to +260℃, adapting to extreme working conditions.

Anti-aging, corrosion-resistant, and extremely chemically stable.

NBR Elastomer:

Excellent elastic recovery, ensuring good sealing performance even after long-term use.

Resistant to hydraulic oil corrosion, perfectly compatible with Komatsu hydraulic oil.

Resistant to compression deformation, extending service life. 50% Metal Support Ring: Made of special heat-treated spring steel with a tensile strength ≥1200MPa. Precise opening gap design provides stable tension and prevents rotational seizure.

3. Reliability and Maintenance Advantages:

Extra-long service life: ≥8000 hours under normal operating conditions, 2-3 times that of ordinary aftermarket parts.

Maintenance-free design: Long-term reliability after one installation, reducing downtime for maintenance.

Precise original factory fit: Designed specifically for D275/D61/D63 series gearboxes, perfectly matching the original factory sealing groove.

Easy replacement: Can be replaced individually without disassembling the entire gearbox, reducing maintenance time by 40%.

Installation Points

Cleaning: Thoroughly clean the sealing groove and shaft surface before installation, ensuring no oil, metal shavings, or other impurities remain.

Lubrication: Apply a dedicated hydraulic system grease (containing MoS₂) to the sealing lip to reduce initial friction.

Correct Installation: Use a dedicated tool to press the seal in smoothly, avoiding folding or deformation of the sealing lip.

Direction Confirmation: Ensure the arrow mark on the sealing ring points towards the hydraulic oil source (pressure side).

Clearance Check: After installation, check the axial clearance to be ≤0.15mm to ensure no movement.

Tending

1. Routine Inspection: Visually inspect the transmission housing and seals for any fluid leaks before each start-up.

2. Regular Maintenance:

Check the transmission fluid level and quality every 250 hours, topping up or replacing as needed.

Check the condition of the sealing rings every 1000 hours, especially after high-temperature, high-load conditions.

Preventive Replacement: It is recommended to perform preventative replacement every 4000 hours or 1 year (whichever comes first) to avoid sudden malfunctions.

Troubleshooting: If abnormal shifting or unstable oil pressure is detected, immediately check the sealing rings and replace them if necessary.

Summarize

The sealing ring 425-15-19250 serves as the "valve of the heart" in Komatsu's D275/D61/D63 series bulldozer transmission system. Its three-layer composite structure ensures exceptional sealing performance under high-pressure, high-speed, and high-temperature conditions. Choosing the original factory sealing ring not only guarantees efficient and stable operation of the bulldozer but also significantly reduces maintenance frequency and total cost of ownership. As a critical component, it enhances equipment reliability and extends service life.