Dry Rolling Bearings

Analysis of Dry Rolling Bearing Technology

1. Product Introduction

Dry Rolling Bearing is a rolling bearing that does not require external lubrication and relies on solid lubricating materials or surface treatment technology to achieve low-friction operation. Its core features include

Lubrication-free design: self-lubricating coating, composite materials, or special heat treatment processes are used to avoid reliance on grease or lubricating oil.

Low-friction performance: friction resistance and wear are reduced by optimizing the surface of the raceway and rolling element.

Extreme environment resistance: suitable for scenes with high temperature, vacuum, strong corrosion, or high cleanliness requirements.

Typical structural types:

Solid lubricating coated bearings: MoS₂, PTFE, or DLC (diamond-like carbon) coating is sprayed on the surface of the raceway or rolling element.

Ceramic hybrid bearings: Si₃N₄ or ZrO₂ ceramic balls are used with steel or stainless steel cages.

Self-lubricating bearings: solid lubricants (such as graphite) are embedded in the cage and slowly released during operation.

2. Product application analysis

(1) Industrial machinery

Food packaging equipment: avoid lubricant contamination and meet FDA/NSF certification requirements.

Textile machinery: reduce fiber adsorption and reduce maintenance frequency.

(2) Transportation

Electric vehicle motor bearings: reduce the impact of grease aging and improve high temperature stability.

Aerospace: suitable for vacuum or extreme temperature environments (such as satellite deployment mechanisms).

(3) Energy and heavy industry

Wind turbine yaw system: salt spray corrosion resistance and maintenance-free design.

Steel continuous casting equipment: stable operation in high temperature environment (up to 400°C or above).

(4) Medical and semiconductor

Medical robots: no particle shedding, meet clean room standards (ISO Class 5+).

Wafer handling robot: ultra-high precision, avoid lubricant volatilization contamination.

3. Summary

Advantages Limitations
✔ Maintenance-free, lower operating costs ✖ High initial cost
✔ Resistant to high temperature, vacuum, and corrosive environments ✖ High-speed performance is slightly inferior to oil lubrication
✔ No pollution, suitable for clean scenes ✖ Targeted selection is required (PV value)
Application scenario priority:

Recommended use: extreme environments, oil-free requirements, and long-term maintenance-free occasions.

Use with caution: ultra-high speed (>10,000 rpm), frequent impact load conditions.

4. FAQ (Frequently Asked Questions)

Q1: What is the life of dry friction bearings?
A1: The life depends on the load and speed, usually 60%~80% of oil-lubricated bearings, but it can be significantly better than traditional bearings in high temperature/oil-free environments.

Q2: Is a running-in period required?
A2: Some coated bearings require a short-term running-in (<50 hours) to form a stable transfer film, and ceramic bearings can be used directly.

Q3: Can it replace all lubricated bearings?
A3: No, the working conditions need to be evaluated (for example, oil lubrication is still recommended for high speed and heavy load).

Q4: How to clean dry friction bearings?

A4: Use lint-free cloth or ultrasonic cleaning (to avoid strong solvents damaging the coating).

Q5: What is the maximum tolerable temperature?

A5: Ordinary coated bearings are about 250℃, and ceramic bearings can reach 800℃ (high temperature resistant cages are required).

5. Selection suggestions

Step 1: Identify the environment (temperature, medium, cleanliness).

Step 2: Calculate the PV value (pressure × speed) and match the bearing load capacity.

Step 3: Select coating/material (such as MoS₂ is suitable for vacuum, PTFE is resistant to chemical corrosion).

Example: Semiconductor equipment can choose DLC coated bearings, and wind power equipment should use ceramic hybrid bearings.\