Precision Bearings Supporting the Next Generation of Electric Compressors

As hybrid and electric vehicles (EVs) continue to gain popularity, their internal systems are evolving rapidly to support higher efficiency and reliability. One critical area of advancement is thermal management — not only for cabin comfort but also for maintaining the optimal operating temperature of lithium-ion batteries and onboard electronics. Within these systems, electric compressors play an increasingly vital role, and at the heart of their performance are high-precision ball bearings.

The Shift from Engine-Driven to Electrified Compressors

In conventional vehicles, air-conditioning compressors were typically powered by the engine through a belt-driven swash plate mechanism. As the industry moves toward electrification, however, these designs are being replaced by scroll-type compressors powered by electric motors.

This transition brings several engineering challenges. Scroll compressors require higher efficiency, quieter operation, and reduced vibration — all while maintaining compactness and reliability under continuous use. These demands have placed new requirements on the components that enable smooth, low-friction motion inside the compressor, particularly the bearings.

How Car Air Conditioners Work — and Why Compressors Matter

Automotive air conditioners regulate cabin temperature year-round and play a key safety role through defrosting and dehumidification. Their operation relies on the refrigeration cycle, a repeating sequence of four stages: compression, condensation, expansion, and evaporation.

• The compressor compresses the refrigerant into a high-pressure, high-temperature gas.
• The condenser releases heat, turning the gas into a high-pressure liquid.
• The expansion valve reduces the refrigerant pressure, lowering its temperature.
• The evaporator absorbs heat from the cabin air, cooling it before it circulates back inside.

Among these stages, the compressor has a defining influence on system efficiency — its precision and performance determine how effectively the entire cycle operates.

Electric Compressors and Vehicle Electrification

Unlike belt-driven compressors, electric compressors are powered directly by the vehicle’s battery, allowing continuous operation even when the engine is off — an essential feature for hybrid and fully electric vehicles. Beyond cabin air conditioning, electric compressors also manage the temperature of battery packs and power electronics, ensuring reliable operation under various driving conditions.

As EV systems grow more complex, these compressors have become key to vehicle safety and efficiency. However, their motor-driven design introduces new demands for mechanical precision and reduced energy loss.

The Role of Ball Bearings in Scroll-Type Compressors

Scroll compressors consist of two interlocking spiral components — a fixed scroll and an orbital scroll — that compress refrigerant smoothly and continuously. For this system to operate efficiently, the gap between the two scrolls must remain extremely small. Any deviation can cause energy loss or mechanical wear.

High-precision ball bearings are used to support the orbital scroll, ensuring stable rotation with minimal friction. These bearings must perform reliably under varying loads and speeds while maintaining tight tolerances. To further stabilize the motion of the orbital scroll, retainer rings — derived from bearing components — are used to prevent unwanted spinning. This ensures consistent compression and minimizes vibration.

Advancing Bearing Design for Electric Compressors

To meet the demands of next-generation compressors, our bearing lineup has expanded to include additional sizes optimized for electric compressor applications. Through ultra-precision machining, the grooves that guide the bearing balls have been refined to achieve smoother surfaces and greater roundness.

These design improvements minimize rotational torque, enabling smooth, efficient movement and contributing to the overall compression efficiency of the system. Likewise, the precision of the retainer rings helps maintain alignment of the orbital scroll during operation, supporting stable, long-term performance.

Supporting the Future of Automotive Efficiency

As automotive electrification continues to accelerate, components such as bearings and retainer rings play an increasingly important role in achieving energy-efficient, low-noise, and durable compressor systems.

Through continuous improvement in precision manufacturing and materials engineering, these small but essential components are helping make modern electric compressors — and the vehicles they power — more efficient and reliable than ever before.