3088071 Genuine Excavator Swing Device Sleeve Sleeves for ZX330

Part number 3088071 is a key bushing or sleeve for Hitachi's original rotary device. According to the Hitachi excavator parts system, it is mainly suitable for the slewing mechanism of medium and large hydraulic excavators such as Hitachi ZX200, ZX240, ZX330 series, and may be used for supporting the transmission shaft of the slewing motor or the planetary carrier shaft sleeve of the slewing reducer. The original part number is 3088071, which should be used as the reference for procurement. Due to the precise internal structure of the rotary device, there are differences in size, material, and fitting tolerances among different types of sleeves, and there is usually no universal substitute part number

This sleeve is a key friction pair component in the rotating device that bears radial loads and provides lubrication. Its core function is to serve as a wear-resistant lining between the shaft and the housing, supporting the rotary transmission shaft or gear shaft, reducing direct friction between metals, and guiding lubricating oil to form an oil film. As an original component, it is usually made of high-strength wear-resistant materials such as tin bronze, bimetallic composite materials, or alloy steel coated with anti friction coatings on the surface. After precision machining and heat treatment, it has high hardness, low friction coefficient, and excellent anti bite performance.

The maintenance core of this sleeve is to ensure sufficient lubrication, regular inspection of clearances, and preventive replacement. When replacing, be sure to thoroughly clean the installation holes and shaft necks to ensure that there are no burrs or impurities. When installing a new sleeve, special tools should be used or the sleeve should be smoothly pressed in by freezing method (cooling and shrinking the sleeve), and direct tapping is strictly prohibited to prevent deformation. After installation, it is necessary to immediately add sufficient lubricating oil and run at low speed without load for a period of time to fully establish the oil film.