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The automotive engine gear housing, cast from aluminum alloy and serving as a precision cover for the timing drive system, is manufactured through an integrated process combining high-pressure die casting and precision machining, combining lightweight construction, high rigidity, and optimized NVH performance. The housing integrates multi-axis mounting reference surfaces and sealing grooves to ensure the precise positioning of critical rotating components such as the crankshaft and camshaft. The aluminum alloy matrix’s excellent vibration isolation and damping properties effectively attenuate noise radiated from gear meshing, creating a quiet cabin environment. The dense casting structure endows the housing with exceptional pressure-bearing and impact-resistant capabilities, allowing it to withstand alternating loads and thermal cycling stresses with ease. The surface undergoes multiple protective treatments, making it resistant to corrosion from fuel, oil, and coolant, and ensuring a long-lasting and reliable protective barrier for the drivetrain through precision engineering.
Product Name: Aluminum Alloy Cast Automotive Engine Gear Housing
Installation Location: Timing gear housing and chain compartment at the front and rear of the engine
Product usage scenarios
1. High-reliability, heavy-duty applications in commercial vehicles
Product Name: High-Strength Die-Cast Aluminum Alloy Timing Gear Housing
Installation Location: Front-end gear drive system of medium- and heavy-duty diesel engines
Designed to meet the demands of all-weather, heavy-duty commercial vehicle operations, this product is die-cast from a high-copper-content aluminum-silicon alloy. The housing is reinforced with thickened walls around the main bearing bore, enabling it to easily withstand the high reaction forces from the idler pulley, tensioner pulley, and hydraulic pump. The integrated sealing surface is precision-machined with flatness controlled to within 0.05 mm. Combined with oil-resistant fluororubber gaskets, this ensures a reliable, lifetime seal and eliminates the risk of leaks. The housing surface undergoes an electrically conductive oxidation treatment followed by a corrosion-resistant coating, passing a 1,000-hour salt spray test. It withstands harsh road conditions such as muddy water and de-icing agents, ensuring trouble-free operation for one million kilometers.
2. Quiet Chain Drive Applications in Passenger Cars
Product Name: Low-Noise, Integrated Die-Cast Aluminum Alloy Timing Chain Cover
Installation Location: Timing Chain Drive System for Small-Displacement Turbocharged Engines
Designed specifically for quiet operation and compact layout in passenger cars, the housing is made of a high-strength, heat-treatment-free AlSi10MnMg alloy, with wall thickness reduced to 2.5 mm while maintaining excellent structural rigidity. The interior cavity integrates mounting slots for the chain guide and oil flow ribs, simplifying the assembly process. The high internal damping characteristics of the aluminum alloy matrix significantly attenuate high-frequency noise generated by chain meshing. Combined with a topologically optimized rib layout, the modal frequencies of the entire cover are shifted away from common rotational speed excitation, resulting in an NVH performance improvement of 30% or more. The lightweight design directly reduces the load on the front end of the engine, contributing to lower overall vehicle fuel consumption.
3. Scenarios Specific to New Energy Hybrid Vehicles
Product Name: Integrated Assembly of Timing Gear Housing and Front Cover for Hybrid Vehicles
Installation Location: Front-end accessory drive system of the hybrid engine
To accommodate the frequent start-stop cycles and dual-mode operation of hybrid engines, the housing is manufactured using a vacuum die-casting process and incorporates mounting holes for front-end accessory brackets, achieving a lightweight, integrated design that combines multiple components into one. The structure has undergone enhanced simulation to withstand the instantaneous impact of the electric motor’s assist torque; localized thickening and a network of reinforcing ribs ensure fatigue life under high loads. The housing’s rapid heat conduction properties allow it to quickly follow the thermal engine’s temperature rise, preventing abnormal noise caused by excessive clearance during cold starts, and perfectly matching the hybrid system’s requirement for smooth power delivery.
Product Specifications
| Parameter Categories | Key Indicators |
|---|---|
| material (that sth is made of) | ADC12 / AlSi9Cu3 / AlSi10MnMg / A380 (selected based on strength and operating conditions) |
| Molding process | Cold-chamber high-pressure die casting + 5-axis CNC precision machining |
| tensile strength | ≥280 MPa (bulk specimen) |
| yield strength | ≥180 MPa |
| elongation | ≥2.51 TP3T |
| intensity | Approximately 2.7 g/cm3 |
| Flatness (Sealing Surface) | ≤0.05 mm (over a 100 mm length) |
| Key Hole Tolerances | Levels IT6–IT7 |
| surface treatment | Conductive Anodizing / Hard Anodizing / Black Oil-Resistant Powder Coating |
| airtight | Dry airtightness test, leakage rate ≤ 5 cc/min @ 100 kPa |
| NVH Performance | First-order modal frequency of the housing ≥ 350 Hz (depending on the structure); damping ratio increased by 20% |
| Salt Spray Resistance | Neutral salt spray test: ≥720 hours (no blistering or rust) |
| Compatible Models | Three-cylinder, four-cylinder, and six-cylinder diesel and gasoline engines, with displacements ranging from 1.0L to 13L |
| weights | Typically 1.5 kg–8.0 kg (depending on the model size) |
| Cleanliness Requirements | Complies with ISO 16232; maximum particle size control is performed in accordance with OEM standards |
Product Advantages
- Integrated precision molding for greater reliability
The housing integrates mounting reference points, oil seal seat holes, sensor mounting positions, and sealing grooves, reducing the number of separate components and cumulative assembly errors. The number of sealing interfaces is reduced by 60%, thereby minimizing the risk of leakage from the design stage. - Outstanding NVH performance for a quieter ride
The high internal damping characteristics of the aluminum alloy, combined with a topologically optimized ribbed design, effectively attenuate gear/chain meshing vibrations, reducing housing-radiated noise by 3–5 dB(A) and providing critical support for the vehicle’s NVH compliance. - Efficient thermal management ensures consistent accuracy
The housing rapidly conducts heat and ensures uniform temperature distribution, preventing valve position drift caused by localized heat buildup, ensuring that the timing system maintains precise phase across the entire operating range, and extending the service life of the timing chain or belt. - Ultra-lightweight design, contributing to vehicle fuel efficiency
Compared to traditional cast iron solutions, this design reduces weight by 40% or more. The reduced weight per vehicle lowers the rotational inertia at the front end of the engine, directly contributing to improved fuel economy. - Long-lasting and corrosion-resistant, it stands the test of time
A dual-barrier system consisting of a conductive oxide base layer and a surface protective layer resists corrosion from complex media such as engine oil, coolant, and road salt spray, ensuring no corrosion-related failures throughout the entire product lifecycle.
Manufacturing & Services
Ningbo Hexin Molding Co., Ltd. has been deeply involved in the field of precision aluminum alloy casting for twenty years, specializing in providing one-stop solutions for automotive powertrains—from collaborative development to mass production and delivery.
Global Service Network
Our products are supplied in bulk to leading domestic and international automakers and Tier 1 suppliers. We are well-versed in standards such as ISO, GB, and JIS, and comply with environmental regulations including REACH, RoHS, and ELV, providing efficient and convenient localized support to customers worldwide.
End-to-End Manufacturing Capabilities
Equipped with the 800T–2000T series of cold-chamber die-casting cells, vacuum die-casting units, and five-axis precision machining centers, the facility is capable of forming and precision-machining complex thin-walled components such as gear housings, with an annual production capacity of 800,000 units.
High-Standard Process Control
The production facility is IATF 16949-certified and equipped with a full suite of testing capabilities, including industrial CT scanners, coordinate measuring machines, airtightness test benches, and a cleanliness laboratory. The process capability index (Cpk) for key characteristics is ≥1.67, and data is fully traceable throughout the entire process.
In-Depth Collaborative R&D
The company operates a joint engineering laboratory that provides engineering services such as mold flow analysis, structural topology optimization, casting process simulation (MAGMA), and NVH prediction. These services support customers throughout the entire development process—from clay modeling to SOP—thereby shortening product time-to-market.
Flexible Delivery Options
Deliveries can be categorized by raw parts, rough-machined parts, and fully machined finished parts. We support VMI consignment inventory and JIT just-in-time delivery to respond quickly to changes in customer demand.
