In the world of precision bearing manufacturing, there are always some processes that seem insignificant but determine whether the product can achieve the expected performance and lifespan. The ultra-precision process is precisely such a procedure. It is not as efficient and conspicuous as assembly processes, nor does it obviously change material properties like heat treatment. Instead, it acts as the final gatekeeper, quietly determining the ultimate quality of the parts.

Bearing superfinishing, also known as superfinishing grinding, is a micro-grinding process. For high-precision bearings, both the rolling surfaces of the rings and the working surfaces of the rolling elements usually need to undergo superfinishing processing. Superfinishing involves various processing equipment and different processing principles. To meet the requirements of geometric accuracy and surface quality, it is necessary to comprehensively consider the equipment, tooling, oilstones, grinding fluids, and even the state of the bearing parts in the grinding process. The main functions of the ultra-precision process are as follows:

It can effectively reduce the waviness. During the superfinishing process, to ensure that the oilstone always acts on the wave peaks and does not come into contact with the wave troughs, the arc of contact between the oilstone and the workpiece is greater than or equal to the wavelength of the waviness on the workpiece surface. As a result, the contact pressure on the wave peaks is relatively large, and the protruding peaks are removed, thereby reducing the waviness.

Improve the groove shape error of the raceways of ball bearings. Superfinishing can effectively improve the groove shape error of the raceway by about 30%.

It can generate compressive stress on the surface to be ultra-finely ground. During the superfinishing process, cold plastic deformation mainly occurs, which leads to the formation of residual compressive stress on the workpiece surface after superfinishing.

It can increase the contact area of the working surface of the ring. After superfinishing, the contact and support area of the working surface of the ring can be increased from 15% to 40% after grinding to 80% to 95%.

In fact, it's not just bearings. In fields such as automobiles, aerospace, and medical devices, parts often need to go through multiple processing procedures before they can be formed. After drilling, boring and grinding, the shape and size of the hole generally meet the requirements. However, to truly achieve strict tolerances and surface quality, a superfinishing process is still needed to complete the final correction step.

The principle of superfinishing technology is to use tools with abrasives to perform reciprocating and rotational movements on the inner wall of the hole to perform micro-cutting on the surface. This method removes a very small amount of material, but it can significantly improve the geometric accuracy and surface quality of the holes. Compared with ordinary grinding, superfinishing has a lower removal rate but higher precision. Due to the slight cutting and low heat generation, the workpiece is less likely to deform due to heat, thus enabling very strict dimensional tolerances to be achieved. This is also why parts with extremely high precision requirements, such as bearing raceways, engine cylinders, hydraulic systems and medical implants, all cannot do without this process. For instance, in engine manufacturing, the cylinder is already very smooth after boring, but without ultra-precision processing, the fit between the piston rings and the cylinder wall is not ideal.

Through superfinishing, uniform cross-mesh patterns can be formed on the cylinder wall, which not only ensures the smooth sliding of the piston but also effectively maintains the lubricating oil film, reducing friction and wear. In the aerospace industry, the manufacturing and maintenance of engine parts, hydraulic systems, fasteners and even bearings all rely on ultra-precision processes to ensure reliability. As for the medical field, even the slightest roughness on the surface of surgical instruments and implants may affect their functions and even trigger rejection reactions. The ultra-precision process enables these products to meet strict geometric accuracy and surface quality requirements, thereby ensuring safe use. In addition to high precision, another notable feature of ultra-precision technology is its strong adaptability. It is almost applicable to all common materials, from cast iron and low-carbon steel to aluminum, copper and composite materials. As long as the parameters are adjusted, the ideal effect can be achieved. Even very small parts can achieve stable surfaces and dimensions through superfinishing. Most modern ultra-precision machine tools have achieved automatic control and can operate continuously for a long time without affecting quality. This means that ultra-precision technology not only represents accuracy but also takes efficiency into account. For enterprises engaged in mass manufacturing, it is an important guarantee for reducing costs and increasing production capacity. The ultra-precision process is supported by a complete set of machine tools and tools.

Horizontal machine tools are suitable for processing long shafts, rods or pipe parts. Vertical machine tools are more suitable for parts with extremely high requirements for precision and consistency, such as complex parts in the automotive and aerospace industries. In terms of tools, super-fine grinding stones are the most crucial part. Diamond grinding stones are suitable for high-hardness materials, while silicon carbide grinding stones are more suitable for soft metals such as aluminum and brass. Lubricating oil is also indispensable. It not only reduces friction and heat but also removes chips, helping to achieve a smoother surface.

Ultimately, the value of ultra-precision craftsmanship lies in making parts more perfect. It offers a longer lifespan for bearing products, stable power output for engines, reliable safety guarantees for aircraft, consistency for mold manufacturing, and functionality and lifespan for medical devices. Without ultra-precision craftsmanship, the parts may still be usable, but they may not be stable or durable. With ultra-precision craftsmanship, parts can truly reach their ideal state. On the track of precision manufacturing, ultra-precision craftsmanship is the "last gatekeeper", silently safeguarding the quality bottom line of every part.