Explore the Lean Manufacturing Journey of Modern High-Performance Bearing shells

Bearing shells, also known as sliding bearings, are critical components in large rotating machinery such as engines, compressors, and turbines. They are used to support shafts and reduce friction. The processing flow may vary depending on the material (metal, bimetallic, Babbitt alloy, etc.) and the final form (thin-walled, thick-walled), but the core processes are similar.  

The entire shaft bearing processing flow can be broadly divided into three main stages:  

Stage 1: Raw Material Preparation  

1. Raw Material Selection and Inspection:  

Bimetallic composite plates are used. The base layer is typically made of low-carbon steel (e.g., 08Al, 10 steel) to provide strength and rigidity, while the friction layer (anti-friction layer) is made of Babbitt alloy (white alloy), copper-based alloy (e.g., lead bronze), or aluminum-based alloy.  

Incoming materials are inspected for chemical composition, metallographic structure, bonding strength (ultrasonic testing), and dimensions.  

2. Blank Cutting and Stamping Forming:  

Blank Cutting: Large composite plates are punched into rectangular blanks of predetermined sizes using large presses and molds.  

Forming: The rectangular blanks are stamped and bent into semi-circular bearing shells using precision molds.  

3. Locating Lug Processing:  

A locating lug (also known as a positioning lip) is machined on the mating surface (also called the opening or split surface) of the bearing shell. This structure is crucial for ensuring precise positioning of the bearing when installed in the bearing housing and preventing rotation. 

Stage 2: Machining  

1. Rough Boring of Inner Hole and Width Cutting:  

Two semi-circular shells are clamped back-to-back using specialized fixtures to form a "dummy shaft."  

Rough boring of the inner hole is performed on a lathe or specialized machine, leaving allowance for finish machining.  

Simultaneously, the outer circle and both sides (width cutting) are machined to ensure total width and parallelism.  

2. Oil Hole Drilling and Oil Groove Cutting:  

Oil Hole Drilling: Lubricant inlet holes and holes leading to the inner surface are drilled at specified locations according to the drawing requirements.  

Oil Groove Cutting: Oil grooves (such as circumferential grooves, diagonal grooves, etc.) are milled on the inner surface using a milling machine or specialized oil groove machine. The shape, depth, and position of the oil grooves must be precise, as they affect oil film formation and load-bearing capacity.  

3. Finish Machining:  

Finish Boring of Inner Hole: This is the most critical finish machining step. A high-precision boring machine is used to process the inner hole of the assembled bearing to the final diameter, geometric accuracy (roundness, cylindricity), and extremely high surface roughness requirements (typically Ra < 0.8μm or even lower).  

Finish Grinding of Mating Surfaces: The two mating surfaces are precision-ground to ensure flatness and precise length dimensions. This dimension determines the "crush height" (or interference fit) of the bearing in the housing, which is critical for bearing fit and heat dissipation.  

Stage 3: Surface Treatment and Final Inspection  

1. Surface Treatment:  

Depending on design requirements, a very thin layer of soft metal, such as tin (Sn), indium (In), or lead-tin (Pb-Sn) alloy, may be plated on the inner surface. This plating layer improves run-in performance, acts as a corrosion barrier, and embeds fine impurities to protect the journal.  

For copper-based alloys, passivation treatment may be applied to prevent oxidation.  

2. Cleaning and Deburring:  

Cleaning agents (e.g., ultrasonic cleaning) are used to thoroughly remove metal chips and oil stains generated during processing.  

3. Final Inspection:  

Dimensional Inspection: Precision measuring tools (e.g., pneumatic gauges, coordinate measuring machines CMM) are used to inspect all critical dimensions, including inner diameter, wall thickness, width, and mating surface height.  

Appearance Inspection: Surfaces are checked for scratches, bumps, rust, and other defects.  

Nondestructive Testing: For Babbitt alloy bearings, ultrasonic testing is commonly used to ensure the alloy layer is firmly bonded to the steel back, with no delamination or porosity defects.  

4. Rust Prevention and Packaging:  

Anti-rust oil is applied to the processed surfaces, and anti-rust packaging film along with specialized packaging boxes are used to prevent rust during transportation and storage.  

Dafeng Mingyue Bearing Bush always adheres to technological innovation, crafting high-end products with exquisite craftsmanship, and providing reliable support for the development of high-end equipment manufacturing industry.