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What is a Gearbox Housing (Gearbox Casing)

Jiaming CaiJuly 6, 2023

DONCEN MOTOR is a professional micro gearbox factory in China. In this article, we take an in-depth look at the material properties, production techniques and main roles of gearbox housings.

What is Gearbox Housing?

Doncen Gearbox

The gearbox housing is the outer casing that contains and protects the internal components of a gearbox, including gears, bearings, and shafts. It’s akin to the skeleton in a human body — providing a structure for the rest of the components to operate in unison.

Material of Gearbox Housing

When discussing the construction of the gearbox housing, the first thing to consider is the material used. This choice of material significantly impacts the overall performance and durability of the gearbox. The most common materials used for gearbox housings include alloys, zinc alloys and ABS.

Different gearbox materials will have different effects on the performance of the gearbox. DONCEN MOTOR focuses on the design of the gearbox housing, and can choose the appropriate material according to the different needs of customers. wedo have an analysis of three common gearbox housing materials.

Aluminum Alloy:


  • Lightweight: Aluminum alloys are lighter than many other metals, which can contribute to reducing the total weight of a system.
  • Corrosion Resistance: Aluminum forms a protective oxide layer naturally, which helps it resist corrosion, especially important in harsh environments.
  • Heat Dissipation: Aluminum alloys are excellent conductors of heat, which is beneficial for components that generate a lot of heat like motors and gearboxes.
  • Strength: Despite being lightweight, aluminum alloys are strong and can withstand substantial loads.


  • Cost: Aluminum alloys are typically more expensive than other common materials used for gearboxes.
  • Wear: Without proper surface treatments, aluminum can wear quickly under high-load or high-speed conditions.

Zinc Alloy:


  • Strength: Zinc alloys are very strong and tough, which makes them ideal for heavy-duty applications.
  • Precision: Zinc alloys can be cast with very high precision, which is beneficial for complex gearbox designs.


  • Weight: Zinc alloys are heavier than aluminum and plastics, which might not be ideal for applications where weight is a concern.
  • Corrosion: Zinc alloys can corrode over time if not properly treated or maintained.

ABS (Acrylonitrile Butadiene Styrene) Plastic:


  • Cost-effective: ABS is typically cheaper than metal counterparts, making it a cost-effective choice for housing.
  • Lightweight: ABS is lighter than metals, which can be advantageous in certain applications.
  • Flexibility: ABS can be molded into complex shapes and sizes, allowing for more design flexibility.


  • Heat Resistance: ABS may not handle heat as well as metal options. High temperatures can lead to deformation or even melting.
  • Strength: While ABS is reasonably strong for a plastic, it’s not as strong or durable as metal options, especially under high load or stress conditions.

Note: The choice of material for the gearbox housing largely depends on the specific requirements of the application, such as load capacity, operating conditions, and desired lifespan.

Manufacturing of Gearbox Housing

The design and production of a gearbox housing is an intricate process that requires a deep understanding of materials and manufacturing methods. There are primarily three methods of producing gearbox housings – aluminum die-casting, CNC machining, and plastic molding. Let’s take a detailed look at each.

Aluminum Die-Casting

The die-casting process involves injecting molten aluminum under high pressure into a steel die or mold. It’s an effective method for producing complex shapes that require a high degree of precision and consistency.

The benefits of using aluminum for gearbox housing include high strength, excellent thermal conductivity, and corrosion resistance. It’s also lightweight, which can contribute to improved efficiency and reduced energy usage in applications like planetary gear motors.

In the die-casting process, the aluminum is heated until it turns into a liquid. It is then forced into the die under high pressure. Once the aluminum cools and solidifies, the die is opened to remove the casting. The result is a highly precise, durable, and uniform part with excellent surface finish.

CNC Machining

CNC (Computer Numerical Control) machining involves the use of computer-controlled machines to cut, mill, and shape a solid block of material. In the case of gearbox housings, this can be a metal such as aluminum or a plastic.

CNC machining is highly versatile, capable of producing a wide range of shapes and designs. It offers excellent precision and consistency, and it’s ideal for producing small to medium quantities of parts.

In CNC machining, a 3D model of the gearbox housing is first created using CAD (Computer-Aided Design) software. This model is then used to control the CNC machine, which cuts and shapes the material to match the design. The result is a highly accurate part with excellent surface quality.

Plastic Molding

Plastic molding involves shaping plastic by heating it until it becomes soft, then forcing it into a mold where it cools and solidifies. For gearbox housings, this process offers the benefits of low cost, light weight, and excellent insulation properties. Moreover, plastics can be molded into complex shapes with high precision.

There are several types of plastic molding, but the most common for gearbox housings is injection molding. In this process, the plastic is first heated until it becomes liquid. It is then injected into a mold under high pressure. Once the plastic cools and solidifies, the mold is opened to remove the part.

Injection-molded plastic gearbox housings are common in applications where weight and cost are significant factors, such as small DC motors.

Each of these manufacturing methods offers unique benefits and is suited to different applications and requirements. At Doncen Motor, we have expertise in all these methods and can advise on the best approach for any given application. To learn more, please visit our catalog or contact our team directly.

What is the main functions of Gearbox Housing?

As a protection device for the gearbox, the gearbox casing is crucial to the entire gearbox system.

  1. Protection: The gearbox housing provides a protective enclosure for the internal components of the gearbox, shielding them from external contaminants such as dust and moisture. This can effectively prolong the working life of the gearbox.
  2. Support: The gearbox housing also provides structural support for the gearbox components, maintaining their proper alignment and ensuring smooth operation.
  3. Heat Dissipation: The gearbox housing also plays a role in managing heat within the gearbox. Materials like aluminum, known for their thermal conductivity, can help dissipate heat generated during operation, preventing overheating and ensuring optimal performance.
  4. Noise Reduction: The housing also plays a crucial role in reducing noise generated by the operation of the gearbox.

In sum, the gearbox housing is a vital component of the gearbox system. Its design and material selection significantly influence the performance, durability, and overall effectiveness of the gearbox. Consequently, understanding the intricacies of gearbox housing is crucial for engineers in the field.

The Challenges of Designing and Manufacturing Gearbox Housing

Designing and manufacturing a gearbox housing is not a simple task. It requires an in-depth understanding of engineering principles, materials science, and the specific requirements of the application. Let’s explore some of the challenges faced in this process.

Designing for Specific Applications

One of the most significant challenges in designing a gearbox housing is meeting the specific requirements of the application. Different applications have different demands – for instance, a solar tracker motor may need a different kind of housing compared to a motor used in an electric valve.

Designers have to consider several factors, such as the operating environment, load capacity, speed requirements, and other mechanical and electrical specifications of the application. All these factors will influence the choice of material, the design of the housing, and the manufacturing process.

Material Selection

Choosing the right material for the gearbox housing can be tricky. As discussed in the previous section, the choice of material greatly affects the properties of the housing, including its strength, weight, heat dissipation capacity, and noise reduction capabilities. Designers need to balance these properties to achieve the best performance.

Moreover, other factors such as cost, availability of materials, and environmental considerations can also affect the choice of material. For instance, although aluminum might be a good choice in terms of weight and heat dissipation, it might not be the most cost-effective option.

Manufacturing Processes

The manufacturing process of the gearbox housing can also pose challenges. The most common method, casting, requires high precision to ensure the accuracy of the final product. Any deviation from the intended dimensions can result in misalignment of the internal components, leading to inefficient operation or even failure of the gearbox.

Moreover, different materials require different casting conditions. For example, cast iron requires higher temperatures than aluminum, and these conditions need to be carefully controlled to ensure the quality of the final product.

Ensuring Durability and Longevity

Lastly, the gearbox housing must be designed and manufactured to withstand the test of time. It should be durable enough to handle the stresses imposed by the operation of the gearbox and resistant to wear and tear.

Achieving this requires careful design, choice of suitable materials, and high-quality manufacturing processes. One must also consider maintenance requirements, as regular lubrication and inspection can significantly enhance the lifespan of the gearbox housing.

Overcoming the Challenges

Designing and manufacturing a gearbox housing may seem daunting, but these challenges can be overcome with a sound understanding of the principles of engineering, materials science, and manufacturing processes.

For instance, computer-aided design (CAD) software can be used to create accurate 3D models of the housing, allowing designers to assess its performance before manufacturing. Furthermore, modern manufacturing technologies, such as CNC machining and 3D printing, can provide high precision and flexibility in the production process.

In the end, it’s all about finding the right balance – between the requirements of the application, the properties of the material, and the capabilities of the manufacturing process. With the right approach, it’s possible to design and manufacture a gearbox housing that meets the highest standards of performance and durability.

Future Trends and the Evolution of Gearbox Housing Design

The gearbox housing field is continually evolving, influenced by the drive towards increased efficiency, environmental considerations, and the integration of new materials and technologies. Understanding these trends will be vital for any business in the industry to stay competitive.

Advanced Materials and Manufacturing Processes

As we’ve noted before, the choice of materials for gearbox housing construction is critical. It influences not just the immediate performance characteristics of the device, such as strength, weight, and heat dissipation, but also broader issues such as cost and sustainability.

Future trends point towards the increased usage of advanced materials like composites and high-performance alloys. These materials can offer significant advantages, including high strength-to-weight ratios, excellent thermal properties, and resistance to environmental conditions. For instance, in an electric hydraulic crimping tool motor, a composite material housing could offer significant weight savings without compromising strength or performance.

Moreover, the manufacturing processes will continue to evolve. 3D printing, or additive manufacturing, is one such promising technology. It can produce complex shapes with high precision, using less material than traditional methods and allowing for more efficient designs.

Greater Integration of Electronics

The future of gearbox housings will also see more integration of electronics, sensors, and control systems. These can provide real-time monitoring and control of the gearbox’s performance, improving efficiency, reliability, and lifespan.

For instance, temperature sensors could help manage thermal loads, while vibration sensors could detect the early signs of mechanical issues. Incorporating these into the gearbox housing design will require new approaches and considerations.

Environmental Considerations and Sustainability

Environmental considerations are becoming increasingly important in all areas of manufacturing, and gearbox housing design is no exception. Reducing energy usage and waste, increasing recycling and reuse, and minimizing the environmental impact of materials and processes are all key goals.

Materials choice will play a significant role here. For example, choosing recyclable materials like aluminum over non-recyclable ones can significantly reduce the environmental impact of the product. Similarly, manufacturing processes that use less energy or produce less waste, such as additive manufacturing, can also contribute to these goals.


The future of gearbox housing design promises to be exciting, with new materials, technologies, and approaches changing the way we think about these critical components. It will require a mix of engineering skill, creativity, and an understanding of these emerging trends.

Whether it’s the incorporation of advanced materials, the integration of electronics and sensors, or the drive towards sustainability, there’s no doubt that the gearbox housing field is set to see significant changes in the years to come.

For more information on the latest trends in gearbox housing design, please visit our catalog or get in touch with our team at Doncen Motor, your trusted provider for professional gearbox solutions.

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