Zero maintenance challenge: How can ultra-high speed bearings achieve lubrication-free?

1. Embedded design of solid lubricants
Substrate selection: Ultra-high speed integrated bearings use high-strength alloys (such as stainless steel, nickel-based alloys) or ceramics (silicon nitride) as bearing skeletons to ensure the structural stability of the bearings at high temperatures.
Distribution of solid lubricants: Solid lubricants such as graphite (temperature resistance 600°C) and molybdenum disulfide (MoS₂, temperature resistance 400°C) are evenly dispersed in the metal matrix as nano-scale particles to form a "lubricant warehouse".
Self-lubricating mechanism: When the bearing is running, the friction heat releases the lubricating particles in the matrix, forming a layered protective film on the surface of the raceway and rolling element (friction coefficient as low as 0.05-0.12), and the bearing continuously releases new lubricant during wear to achieve self-replenishment.

2. Surface engineering and material innovation
Mirror-grade raceway polishing: The surface roughness of ultra-high-speed integrated bearings is controlled at Ra≤0.05μm, reducing the friction resistance caused by micro-protrusions.
Diamond-like carbon coating (DLC): DLC coating is deposited on the bearing raceway, with a hardness of HV 2000–4000 and a friction coefficient as low as 0.01, which significantly reduces the wear rate.
Application of ceramic hybrid bearings——
Silicon nitride (Si₃N₄) rolling elements: 60% lighter than steel, low thermal expansion coefficient, small high-speed centrifugal deformation, and low affinity with metal surfaces, reducing adhesive wear.

3. Update of sealing system
The bearing adopts a multi-stage stepped sealing groove design with a clearance controlled at 5–20μm, which not only blocks external dust/water vapor, but also prevents high-speed airflow from carrying away lubricating particles.
Metal corrugated spring + PTFE composite seal: The corrugated spring provides constant radial pressure, and the PTFE lip adapts to the thermal deformation of the shaft to achieve dynamic sealing (temperature resistance 250℃).

4. Thermal management strategy
Hollow roller/ball: fill with helium to accelerate heat conduction; or design internal flow channels to guide airflow to dissipate heat.
Thermal matching material combination: such as ceramic ball + Invar cage, the thermal expansion coefficient is close to avoid high temperature jamming.
Cooling air flow coordination: eddy current cooling channel is integrated in the bearing seat, and a small amount of dry air (0.1-0.5L/min) is introduced to reduce the temperature and assist the distribution of solid lubricants.