What types of chains are there?

What types of chains are there?

As core components for mechanical transmission and load-bearing, chains have long been used in various fields, including industrial production, transportation, and daily life. The requirements for chain strength, precision, and corrosion resistance vary greatly across different scenarios, leading to a wide variety of chain types. This article will systematically review mainstream chain types based on application scenarios and structural characteristics, analyzing their core features and applicable areas, providing a comprehensive selection guide for foreign trade buyers, engineers, and industry practitioners.

1. Classification by Transmission Function: The “Power Link” of Industrial Transmission

Transmission chains are key to transmitting power in mechanical systems. They achieve motion and power transmission through the meshing of chains and sprockets, and are widely used in equipment such as machine tools, automobiles, and agricultural machinery. Based on their structure and application, they can be divided into the following categories:

1. Roller Chain
The roller chain is currently the most widely used transmission chain in the industrial sector. Its structure consists of inner and outer link plates, pins, bushings, and rollers. The presence of rollers changes the meshing between the chain and sprocket from sliding friction to rolling friction, significantly reducing wear and energy loss.

Key Features: High transmission efficiency (typically 95%-98%), strong load-bearing capacity, and excellent adaptability. They can operate stably in multi-axis transmissions and harsh environments (such as dust and oil).

Applications: Low- to medium-speed, high-load transmission systems such as motorcycle engines, conveying machinery, agricultural harvesters, and mining equipment.

Critical Selection: Choose a chain number based on the transmitted power, speed, and center distance (e.g., 08A, 10A in the ISO standard; larger chain numbers indicate larger chain pitches and greater load-bearing capacity).

2. Bushing Chain

Bushing chains have a similar structure to roller chains, but lack rollers; the bushings contact the sprocket teeth directly. Due to the larger sliding friction area, their transmission efficiency is slightly lower than roller chains, but they offer lower manufacturing costs and a simpler structure. Core Features: Low cost, easy maintenance, and suitable for light-load, low-speed transmission applications.
Applications: Small conveyors, household appliances (such as washing machine transmissions), light agricultural machinery, etc.

3. Silent Chain

A silent chain, also known as a toothed chain, consists of a series of toothed plates connected by pins. The teeth of the plates precisely mesh with the teeth of the sprockets. Compared to roller chains, toothed chains produce significantly lower noise, offer higher transmission accuracy, and can achieve high speeds.
Core Features: Smooth transmission, low noise, low impact vibration, and high transmission accuracy. Maximum speeds can reach over 4000 rpm.
Applications: Precision machine tool spindle drives, automotive engine timing systems, textile machinery, and other equipment with high noise and precision requirements.

II. Classification by Conveying Function: The “Conveyor Corridor” of Material Handling

Conveyor chains are designed specifically for material handling and must be able to continuously convey and carry materials. They are typically used in conjunction with conveyor belts, conveyor tracks, and other devices. Depending on the material form and environment being conveyed, they can be divided into the following main types:

1. Plate Chain

A plate chain consists of a chain and a carrier plate, which is connected to the chain via pins or bolts to form a continuous conveying surface. Depending on the structure of the carrier plate, it can be categorized into various types, including flat plate, baffle, and side guide.

Key Features: High load capacity, a smooth conveying surface, and the ability to transport a variety of materials, including bulk, granular, and boxed materials. It is also easy to clean.

Applications: Automated production lines, food processing conveying (such as cookie baking lines), warehousing and logistics sorting systems, and mining material handling.

2. Wire Mesh Chain
Wire mesh chains are constructed from a mesh structure of woven metal wires, which are then connected to chains to form a conveyor. They offer excellent air permeability, are lightweight, and resist material accumulation.

Key Features: Excellent air permeability, heat dissipation, and low conveying resistance, enabling simultaneous drying and cooling of materials.

Applications: Food drying lines (such as instant noodle frying conveyor), electronic component drying, and aseptic conveying in the pharmaceutical industry.

3. Overhead Chain
Overhead chains are installed on overhead tracks, with hooks or load frames suspended from them. They enable aerial conveying and transfer of materials, effectively saving floor space.

Key Features: High space utilization and flexible conveying paths (capable of turning and lifting), making them suitable for long-distance, three-dimensional material transport.

Applications: Automotive parts assembly lines (such as body painting conveyor), garment hanging production systems, and three-dimensional conveying in warehousing and logistics.

III. Classification by Special Application: “Specialized Weapons” for Extreme Environments

In some specialized working conditions, ordinary chains are insufficient. Therefore, specialized chains with special properties such as corrosion resistance, high temperature resistance, and high strength have emerged. These chains primarily include:

1. Stainless Steel Chain

Stainless steel chains are made of stainless steel materials such as 304 and 316. They offer excellent corrosion resistance, oxidation resistance, and hygienic properties, making them ideal for harsh environments such as those involving humidity, acidity, and alkalinity.

Key Features: Strong corrosion resistance, rust resistance, and a smooth, easy-to-clean surface, meeting the hygienic requirements of industries such as food and pharmaceuticals.

Applications: Food processing equipment, chemical conveying systems, marine engineering equipment, and medical devices.

2. High-Temperature Resistant Chain

High-Temperature Resistant Chains are made of high-temperature-resistant materials (such as heat-resistant steel) and are equipped with high-temperature grease. They can operate stably in environments exceeding 300°C, and some specialized models can withstand temperatures exceeding 800°C. Core Features: High-temperature oxidation resistance, strong resistance to thermal deformation, and stable lubrication.
Applications: High-temperature operating environments such as the metallurgical industry (e.g., billet conveying), glass manufacturing equipment, and incinerator feed systems.

3. Lifting Chain
Lifting chains are core load-bearing components of lifting equipment and require extremely high strength and toughness. They are typically made of high-strength alloy steel and undergo quenching and tempering to ensure safe load-bearing.
Core Features: High tensile strength, good toughness, and a high safety factor (typically no less than 4). Surface treatments such as blackening and galvanizing are often used to prevent rust.
Applications: Cranes, forklifts, and lifting equipment used for lifting and transporting heavy objects.

IV. Classification by Chain Structure: “Differentiation” of Basic Forms

In addition to classification by function, chains can also be categorized based on their structural differences, which directly impact their performance and applicable scenarios:

1. Single-strand vs. Multi-strand Chains

Single-strand chains consist of a single set of links and are simple in structure, suitable for transmission and conveying of medium and low loads. Multi-strand chains consist of multiple sets of single-strand chains connected by pins, and their load-bearing capacity increases with the number of strands (typically limited to four to avoid uneven load distribution).

Applications: Single-strand chains are used for small equipment, while multi-strand chains are used for industrial transmission of high loads (such as large compressors).

2. Short-pitch vs. Long-pitch Chains

Pitch is a core parameter of a chain, referring to the distance between the centers of two adjacent pins. Short-pitch chains (pitch ≤ 25.4mm) offer high transmission accuracy and high speed, making them suitable for precision transmission. Long-pitch chains (pitch ≥ 50.8mm) offer high load-bearing capacity, suitable for low-speed, high-load conveying.

V. Key Considerations for Chain Selection

After understanding chain types, accurate selection is crucial to ensuring stable equipment operation. Focus on the following four key points:

Operating Parameters: Clarify key parameters such as transmitted power, rotational speed, conveying speed, and load capacity to match the chain’s load capacity and transmission efficiency.

Environmental Conditions: Select specialized chains such as stainless steel or high-temperature-resistant chains based on the presence of corrosion, high temperatures, dust, and humidity.

Installation Space: Determine the chain pitch, number of rows, and length based on the equipment’s installation dimensions and center distance.

Maintenance Requirements: Consider the ease of maintenance required for the application scenario. For example, in the food industry, easy-to-clean mesh chains or stainless steel chains are preferred.

Conclusion

Chain classification is not absolute; chains may overlap under different classifications (for example, a stainless steel leaf chain can be classified as both a stainless steel chain and a conveyor chain). In practical applications, a comprehensive assessment based on specific needs is necessary.