Sinbo Precision High Precision Bushing Machining Case Aviation Hydraulic System Thin Wall Bushing Parts Manufacturing

Sinbo Precision is an expert in precision mechanical processing, specializing in the manufacturing of high-precision bushing parts. The following case study showcases the company's technical capabilities and quality control in bushing machining.

An aviation manufacturer required a batch of high-precision bushing parts for aircraft hydraulic systems. The bushings were made of tin bronze, with a wall thickness of only 2mm, a coaxiality tolerance of 0.025mm, high surface roughness requirements (Ra ≤1.6μm), and excellent wear and corrosion resistance.

• Thin-Wall Structure Prone to Deformation: The bushing wall thickness was only 2mm, making it susceptible to deformation during machining due to cutting forces or clamping pressures.

• High-Precision Requirements: The coaxiality tolerance between the inner hole and outer circle was 0.025mm, demanding high dimensional accuracy.

• Material Machining Difficulty: The tin bronze material is relatively soft, prone to cutting vibrations that affect surface quality.

Sinbo Precision achieved high-quality machining through the following technical measures:

1. Process Design:

   • Adopted a "one-time clamping turning" process to reduce repeated positioning errors and ensure coaxiality between the inner hole and outer circle.

   • Separated rough and finish machining, leaving a 0.5mm allowance for roughing and allowing sufficient cooling before finishing to avoid thermal deformation.

2. Special Tooling Design:

   • Used segmented soft jaws and mandrels for clamping to increase contact area and reduce thin-wall part deformation.

   • For inner keyway machining, employed a broaching process to ensure dimensional and symmetry requirements.

3. CNC Machining Technology:

   • Utilized high-precision CNC lathes (such as Sinbo's self-developed fully automatic CNC lathes) for machining, improving accuracy by 2 times compared to conventional equipment.

   • Selected 10° internal groove tools to avoid interference with the inner hole wall.

4. Quality Control:

   • Used gantry-type CMMs to inspect dimensions and coaxiality, ensuring compliance with aviation standards (e.g., AS9100).

   • Applied grinding and polishing for surface treatment to achieve Ra1.6μm roughness requirements.

• The bushing parts fully met design requirements, with coaxiality controlled within 0.025mm and surface roughness reaching Ra1.6μm.

• Machining efficiency increased by 1.5 times, thanks to Sinbo Precision's optimized CNC equipment and process innovations.

• The client used the bushings in hydraulic systems for Airbus A320 and domestically produced C919 aircraft, reporting stable and reliable performance.

• Technical Expertise: Possesses 33 high-precision CNC machining centers and AS9100 aviation quality certification.

• Innovative Processes: Self-developed CNC lathes improve machining accuracy and production efficiency.

• Customization Capability: Supports OEM and ODM services, able to adjust materials, dimensions, and surface treatments according to customer needs.