Unveiling the Manufacturing Process of Funei Precision’s Bearing Housings: The Technological Secrets Behind Its Premium Quality

In the field of mechanical manufacturing, bearing housings serve as critical foundational components that support rotating parts; their machining quality directly impacts the operational accuracy and service life of the entire machine. Leveraging a unique process flow and precision machining technologies, Funeng Precision has developed high‑precision bearing housings for a specific model. This article delves into the complete manufacturing process of Funeng Precision’s bearing housings, uncovering the technical secrets of precision machining and illustrating the transformation from raw blanks to finished products.

▶ Process Origin: High-Quality Blank Casting

▼Conventional Lathe: In the initial stage, rough machining is performed on a Φ80×200 bar stock, followed by drilling through-holes and turning external cylindrical steps.

By employing a strategy of “rough‑finishing separation” combined with “precision correction and head‑turning,” IT7‑grade dimensional accuracy and Ra 3.2 surface finish are achieved on a conventional lathe. Key control points—clamping‑induced deformation suppression and toolpath optimization—highlight the process potential of traditional machine tools.

▶ Datum Surface Machining: Laying the Foundation for Precision

▼CNC Lathe: The half‑open is rough, and the internal bore has been roughed out to the proper depth.

This process fully leverages the high performance of Hardinge CNC lathes, achieving precise machining of the internal bores and external diameters at both ends of complex workpieces through a meticulously designed clamping scheme, staged precision alignment, an efficient rough‑machining strategy, and a rigorously organized sequence of operations. Its key features lie in the accurate establishment and transfer of datums, the rational division of labor between roughing and finishing operations coupled with seamless integration, and the thorough exploitation of the machine tool’s full precision potential—hallmarks that vividly underscore Fune Precision Manufacturing’s technical excellence.

▶ Five-axis simultaneous machining: Enhanced quality and precision

▼CNC five-axis machining center: The internal thread milling process is consistent, ensuring compliance.

This process employs a closed-loop technical workflow—comprising precision clamping and alignment, five-axis simultaneous machining, and in-process quality monitoring—to address challenges such as maintaining thread consistency across multiple specifications and controlling deformation in thin-walled components. Compared with conventional three-axis machining, it reduces cycle time by 40%, lowers the scrap rate from 5% to 0.3%, and achieves thread‑fit accuracy meeting the GB/T 197‑2018 Grade 6H standard.

▶ Precision quenching: sharply enhances hardness and toughness.

Vacuum heat‑treatment equipment is employed, with rigorous control of the heat‑treatment process, humidity, and holding time, to minimize part distortion and ensure that the parts meet the required hardness specifications.

▶ Turning and finish milling: micron-level correction control

▼CNC Lathe: Finish turning, machining the inner bore and outer diameter, with step dimensions accurately set.

This process description illustrates the use of a high-precision CNC lathe and precision fixtures, combined with rigorous datum‑based clamping, stepwise precision alignment, meticulous allowance control, and cutting‑edge vibration‑damping tooling, to achieve precise machining of both inner and outer diameters at both ends of shaft‑type components, ensure accurate overall length, and accurately dimension stepped features. It particularly addresses vibration issues in internal bore machining, guaranteeing a high‑quality surface finish free of scratches. The distinctive features of this process are encapsulated in five key aspects—“datum consistency,” “micron‑level correction control,” “rigid constraint,” “precise allowance management,” and “active vibration suppression”—which together represent the hallmark of Funeng’s precision turning operations.

▶ Precision Grinding: Phase-Based Datum Optimization

▼ Internal and External Cylindrical Grinder: The neck‑machining datum A, with the outer diameter exposed, ensures cylindricity and a reliable positioning datum.

This process, through high-rigidity clamping, staged datum optimization, and integrated multi‑axis machining, has achieved the following on long‑shaft components:

1. Critical dimension accuracy: IT6 for holes, IT5 for external diameters.

2. Geometric Tolerances: Cylindricity ≤ 0.005 mm, Coaxiality ≤ 0.01 mm

3. Surface roughness Ra ≤ 0.4 μm

It embodies Funa’s core philosophy in precision grinding: “establishing the datum first, balancing rigidity with flexibility, and achieving composite efficiency.”

▶ Precision operation: Ensure torque meets specifications.

▼Fitter: Deburr, clean the threads, and remove water residues with a tap.

Use a file, an oilstone, or a dedicated deburring tool to remove flash and burrs from the edges of bearing housings, hole openings, and other areas, ensuring a smooth contact surface to prevent scratching mating parts or compromising sealing during assembly. For through‑hole threads, employ straight‑flute taps to quickly clear debris. Residual water can lead to thread corrosion; when cleaning with a tap, use compressed air to blow out any remaining moisture or rinse with anhydrous ethanol to thoroughly remove water and electrolyte residues.

▶ Programmatic Measurement: Micron-Level Precision

▼ZEISS Coordinate Measuring Machine: Using a measurement system, geometric parameters such as hole diameter, center-to-center distance, flatness, perpendicularity, and cylindricity, as well as the distribution of mounting hole locations, are inspected.

Equipped with high-resolution grating scales and precision probes, the system achieves μm‑level measurement accuracy, meeting the stringent dimensional and geometric tolerances—such as flatness, coaxiality, and positional accuracy—required for bearing housings. The measurement system allows flexible adjustment of probe angles to prevent interference, enabling the inspection of deep holes and concealed features. Finally, it generates a CMM inspection report to ensure rigorous quality control of the product.