Cooler Motor Shaft

In an Electric Power Steering (EPS) system, the motor shaft plays a crucial role. One end connects to the motor, and the other connects to the reduction mechanism. The motor's speed and torque are transmitted entirely through this shaft. If the cooler motor shaft is not strong enough or is out of balance, the steering wheel can feel rough, vibrate, or produce noise.

We have been producing hardware for 20 years, from stamping molds to auto parts. One principle guides us: critical components must be made as a single piece, not assembled from multiple parts. Our cooler motor shaft is cold-forged in one piece, eliminating assembly errors. Power transmission is direct and precise, like a "hard connection".

For example, we supply motor shafts to a leading motor company in China. They require the product to maintain coaxiality ≤ 0.02 mm even after 100,000 forward-reverse cycles. Our cold-forged shafts meet this requirement, and batch stability reduces the need for inspecting every incoming unit.

This shaft is not turned on a lathe; it is formed by "squeezing" the metal into shape under high pressure. We use 20# or 45# steel and cold forge it in one shot using 200–500 ton presses with precision molds.

Cutting severs the metal's internal fiber structure, like cutting a rope - strength is reduced. Cold forging allows the metal fibers to flow continuously along the shaft, with no breaks from end to end. The benefits are:

• Torsional strength increases 20–30%: Handles sudden acceleration and steering shocks better than machined shafts.

• Precision reaches IT8–IT9 grade: Critical features like journals and splines are formed in one step, requiring minimal machining before assembly.

• Coaxiality controlled within 0.02 mm: Essential for stable high-speed operation.

Material utilization exceeds 90%, with almost all raw material incorporated into the finished part and only minimal flash trimmed. This reduces costs and demonstrates our commitment to environmental responsibility.