Aluminum Alloy Wheel Hub (ZL270LF)

Shandong Zonxin Auto Parts Co., Ltd. pioneered the application of ZL270LF aluminum alloy material for manufacturing commercial vehicle wheel hubs. Through optimized design, the product achieves lightweight, high strength, excellent heat dissipation, and strong resistance to thermal fade. This product has entered mass production and sales with favorable market feedback.

1) Material

A new lightweight, high‑strength cast aluminum alloy ZL270LF replaces QT450 (cast iron) material.
ZL270LF aluminum alloy overcomes the shortcomings of traditional cast aluminum alloys—low elongation and inability to be forged or extruded, poor fluidity, and performance decline after casting. It is a new high‑strength material that integrates the advantages of cast aluminum alloys and wrought (deformable) aluminum alloys. The material is castable, forgeable, and extrudable, breaking the boundary between cast and wrought aluminum alloys. This development is domestically pioneering and internationally advanced.

2) Structure

Based on the existing structure, two additional rows of reinforcing cooling ribs were added to improve ventilation and surface cooling efficiency, fully resolving the hub overheating issue during operation. The design has obtained 1 national utility model patent and 6 national industrial design patents.

3) Process

Low‑pressure aluminum alloy casting blank → T6 solution treatment → rough machining → finish machining → surface treatment

4) Assembly

Parts cleaning → servo detection of bearing height difference → hub‑bearing clearance inspection → hub preheating → pressing in bearing outer ring → pressing in oil seal and ABS tone ring → assemble spacer → measure and inspect bearing running clearance → final installation.

Due to the difference in thermal expansion coefficients between aluminum alloy and steel parts, the fit dimensions between the bearing and the hub bore are significantly affected by temperature. After verifying the machining tolerances for the hub inner bore, a special pressing process was adopted to address bearing walk problems under large interference fits. The production line is equipped with high‑precision displacement sensors with a reciprocating precision error ≤ 0.015 mm, allowing precise control of hub running clearance. Compared with traditional processes, this method reduces hub running clearance by 60% and increases service life by 300%.

5)Temperature Performance Parameters

Using the ZL270LF aluminum alloy hub, the wheel-end temperature rises only 30°C above the ambient temperature, which is significantly better than the 60°C rise of traditional hubs, achieving a 50% reduction in wheel-end temperature. This greatly reduces the safety risks caused by wheel-end overheating and completely eliminates the problem of wheel-end fires.

6) Weight

The ZL270LF aluminum alloy disc hub reduces weight by 10.5 kg compared with the QT450 disc hub (a 43% reduction); for a three‑axle semi‑trailer, the total vehicle weight reduction is 63 kg. The ZL270LF aluminum alloy drum hub reduces weight by 12.7 kg compared with the QT450 drum hub (a 56% reduction); for a three‑axle semi‑trailer, the total vehicle weight reduction is 76.2 kg.

7) Product Benefits

Assuming a semi‑trailer transport cost of approximately RMB 0.35 per ton‑km, a daily driving distance of about 450 km, and an annual utilization of about 300 days, a three‑axle semi‑trailer equipped with aluminum alloy hubs (reducing vehicle weight by 76.2 kg per vehicle) can achieve additional income of approximately RMB 3,600 per year.