LiuGong genuine bushing spare parts, quality assurance

Bushing

Bushing

Genuine

Aftermarket Parts

Material

20CrMnTi or Copper Alloy

45 Steel

Heat Treatment Process

20CrMnTi: Normalizing + Surface Carburizing ; Copper Alloy : No heat treatment required

Heating and Quenching

Carburized Layer Thickness

1.6mm( Copper alloy does not require carburizing )

0.8mm

Drawing Design

Designed according to the overall machine installation requirements

General Market

Dimension Control

Strictly according to drawing requirements

No drawing requirements

Surface Roughness

Grinding Machine Processing

Simple Processing

Lubrication Method

Some use graphite lubrication ( No need to grease )

Need to grease daily Oil

Kingpin Bushing

Key factors determining pin and bushing

1. Material :  The genuine LiuGong excavator pin uses 40CrMo or 40Cr material, the bushing uses 20CrMnTi or copper alloy material, which has high strength and hardness, and good toughness and hardenability, and is not easy to deform or crack ;
2. Process :  Unlike the simple heating and quenching process of general aftermarket products, LiuGong's original pin and bushing have different heat treatment processes depending on the material used. ， Designed different heat treatment processes ；

3. 40Cr、40CrMo ( pin ):  Tempering Treatment + Surface quenching, using the tempering process in tempering treatment to eliminate the internal stress of the material, greatly improves the material of the pin, improves the strength, plasticity and toughness of the pin, making it less prone to deformation ;

4. 20CrMnTi ( Bushing ):  Normalizing + Surface carburizing treatment ; Using the normalizing process, not only improves the strength of the material, but also significantly improves the toughness of the material, reducing the tendency of the bushing to crack. Surface carburizing treatment improves the surface hardness and wear resistance of the material. In each heat treatment process, the heat treatment temperature and time are strictly controlled to ensure the comprehensive performance of the product. ;
5. 5. Size Standard : LiuGong genuine pins and bushings have strict size and precision requirements. During production, they are strictly produced according to the design requirements of the drawings. Before leaving the factory, they undergo strict testing to ensure that each product perfectly matches the corresponding machine. However, the kingpins and bushings circulating on the market cannot be produced according to LiuGong's drawings, and there are no requirements for size and precision, so it is easy to cause problems such as inability to install and misalignment of oil ports.

Hazards caused by using aftermarket, low-quality pins and bushings

• Poor raw materials and imperfect heat treatment process lead to poor quality of pins and bushings, easy breakage and rapid wear;

• Incorrect dimensions, installation deviation ;  Incorrect oil port position, unable to lubricate normally ;

• The surface is too rough, increasing the wear of the contact surface, and accelerating the wear of the pin ；

Pin

Advantages of LiuGong OEM kingpins compared to aftermarket kingpins and bushings

Kingpin            Genuine                     Aftermarket Parts

Material            40CrMo or 40Cr           45 Steel, 40Cr

LiuGong genuine pin has a thick heat treatment layer, which is more wear-resistant

LiuGong genuine pin: Smooth surface, not easy to wear

Aftermarket parts: Rough surface, easy to rust, thin heat treatment layer, easy to wear

Heat Treatment Process      Tempering Treatment Treatment + Surface Quenching         Heating and Quenching

Heat Treatment Layer Thickness    8mm                    3-4mm

Drawing Design         Designed according to the overall machine installation requirements      General Market

Dimension Control         Strictly according to drawing requirements          No drawing requirements

Surface Roughness       Grinding Machine Processing                  Simple Processing