4452970 Original Excavator Spring Disc Gasket for ZX670-5B ZX870-5B ZX890-5A

Part number 4452970 is the official part number for Hitachi's original Belleville washer. This component is a cone-shaped annular elastic washer that utilizes its axial deformation to provide strong nonlinear elastic force. It is mainly used inside core assemblies such as hydraulic pumps/motors and rotary reducers to apply and maintain precise axial preload force on bearings, gears, or friction plate groups to eliminate axial clearance, compensate for thermal expansion and wear, and prevent loose connections. As an original standard component, it is commonly found inside the key transmission parts of large excavators in the Hitachi ZX series (such as ZX200, ZX330) and EX series.

This original disc spring washer is a high-precision, high load elastic component. Its core function is to provide axial elasticity and deflection far greater than ordinary flat washers in a limited installation space through elastic deformation of the conical section, thereby achieving stable pre tightening, reliable anti loosening, and effective gap compensation. As an original component, it is usually made of high-quality spring steel through precision stamping, heat treatment, and surface rust prevention treatment, with extremely high fatigue strength, stable elastic modulus, and good corrosion resistance. Its key dimensions and load deformation characteristics have been precisely calculated and tested to ensure the precise pre tightening force required by the design can be generated after installation in the assembly. It is a key basic component to ensure the smooth, low-noise, and long-life operation of the transmission system.

The maintenance core of this disc spring washer lies in preventive inspection, standardized disassembly and assembly, and absolute prohibition of repeated use. Inspection timing: Usually, this component is only disassembled and inspected when the relevant assembly (such as hydraulic pump, rotary motor) is undergoing major repairs or when there is axial abnormal noise or looseness. Inspection content: After disassembly, it is necessary to check for permanent deformation (collapse), cracks, rust or severe wear, and measure its free height to compare with the standard value in the maintenance manual or new parts. If the height loss exceeds the standard, it must be replaced. Installation specifications: The disc spring washer is a disposable component and must not be reinstalled after disassembly.