4379184 Original Excavator Boom Cylinder Liner Parts Pin Bushing for EX2500-5 EX2600E-6LD

Part number 4379184 is a specialized part number for Hitachi's original excavator bushing. The bushing is a key wear-resistant and guiding component at the hinge points of the front-end working devices of excavators (such as the boom, arm, and bucket). It is embedded in the ear plate of the connecting hole and cooperates with the pin shaft to form a sliding bearing pair, which can withstand huge radial loads and impacts, while reducing direct friction between metals and protecting the ear plate hole from wear. As an original standard component, it is usually compatible with key connection parts such as boom boom, boom bucket, and connecting rod bucket of multiple hydraulic excavators in Hitachi ZX series (such as ZX130, ZX200, ZX250, ZX350, etc.) and EX series (such as EX120, EX200, EX300, etc.). In the aftermarket, this part is often referred to as a "shaft sleeve," "wear-resistant sleeve," or "copper sleeve" based on its installation position.

The bushing is the core wear-resistant component of the hinge point of the excavator working device. Its core function is to act as an intermediate wear-resistant layer between the pin shaft and the structural component (ear plate), transferring the sliding friction between the two to the lining itself, effectively protecting the higher priced pin shaft and structural component body, and extending the overall service life; At the same time, it can also absorb some impact vibrations, ensuring smooth and accurate movement of the connecting parts. As an original Hitachi component, it is usually made of special materials with high strength and wear resistance. Common materials include copper alloy or alloy steel. It is usually designed with oil storage tanks or lubrication holes inside, which facilitate the addition of lubricating grease to form an oil film and reduce the friction coefficient.

The maintenance core of this bushing lies in regular lubrication, clearance inspection, and preventive replacement. Regular lubrication: It is necessary to strictly follow the provisions of the equipment maintenance manual (usually every 8-50 working hours), and add the specified type of lithium based grease to the lubrication channel of the liner through the grease nipple until the old grease is squeezed out from the edge of the sealing ring, ensuring that a complete oil film is formed on the friction surface. The lifespan of the bushing is directly related to the adequacy of lubrication, the cleanliness of the lubricating grease, and the integrity of the pin surface. When replacing the bushing, it is necessary to synchronously check and replace the corresponding pin shaft and dust seal as appropriate to ensure the fitting accuracy of the entire hinge pair.