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With the continuous improvement in automation, conveying equipment has been widely used. Conveying equipment can be classified according to the type of its main working components into: chain conveyors, belt conveyors, pneumatic conveyors, screw conveyors, etc. Among all these conveying devices, chain conveyors come in a wide variety of types and specifications, and are the most widely used. 1. Drive unit: Chain conveyor equipment generally operates at relatively low speeds, but it has high transmission torque and high transmission power. Therefore, the drive device is usually composed of a motor reduction unit. The conveyor chain is driven and objects are transported by rotating the drive shaft of the conveying equipment through a driving mechanism. The support for the drive shaft generally uses double-row self-aligning ball bearing housings (except for angle-drive suspension conveyors). Since the self-aligning ball bearing housing has an automatic alignment function, it ensures the normal operation of the conveyor even when there is a certain amount of coaxiality error between the two supports, and the double-row bearings guarantee that it has sufficient load-bearing capacity. The connection between the main shaft and the sprocket is achieved using a key. The drive device must also be equipped with safety protection mechanisms. The traditional form of such mechanisms is a safety pin, which breaks under overload conditions, but its restoration requires time and effort. A relatively advanced safety device at present is one that features an elastic base equipped with an electrical limit switch; when the torque output by the reducer exceeds the allowable level, the elastic base comes into contact with the electrical limit switch, which then activates to cut power to the main motor promptly. Once the fault is resolved, it can reset automatically. When the total length of the equipment is large and the load is high, causing excessive tension in the chain if driven by a single drive unit, an auxiliary drive unit can be installed in the middle of the equipment, with the two drive units connected to each other using a hydraulic coupling. When the load exceeds the capacity of the main drive unit, the auxiliary drive unit is activated. When the load is within the capacity range of the main drive unit, the auxiliary drive unit stops automatically. Due to differences in motor characteristics, it is not possible to ensure that the speeds of the two motors are exactly the same; therefore, the two drive units should not be designed to operate simultaneously for extended periods, as this could result in additional stress on the chain due to differing output speeds of the drive units (this design is commonly used for the drive units of long-distance suspension conveyors) ； When designing a drive system, it is necessary to calculate parameters such as traction force, torque, and power, and based on these calculations, select the appropriate motors, gearboxes, frequency converters, chains, bearing housings, drive shafts, and safety devices. 2. Tensioning device: Chain conveyor equipment uses chains as the main carrying element. Due to the relatively large allowable length tolerance of chains, wear during use can also cause the pitch of the chains to increase. Therefore, chain conveyor equipment must be equipped with a tensioning device. The tensioning stroke of the tensioner is related to the pitch of the working chain and the length of the conveyor line. The design principle for the amount of tension is to ensure that it can accommodate both the allowable tolerance in chain length and the permissible wear-induced elongation equivalent to two chain links. This guarantees that after the chain has worn down by this amount, two links can be removed while still allowing the conveyor to operate normally, thereby extending its service life. The structures of tensioning devices include screw tensioning mechanisms (such as belt or chain conveyors), spring tensioning mechanisms, and weight-driven tensioning mechanisms (such as suspension conveyors). Since the chain tension in chain conveyor equipment is usually high, when using a spiral tensioning mechanism, it is essential to ensure that the tensioning screw is subjected to compressive stress rather than tensile stress, in order to meet the requirements regarding its strength and stiffness. This is especially important when the shaft support of the tensioning mechanism is made of cast iron. The support for its shaft generally uses a double-row self-aligning ball bearing with sliding seats. This type of bearing seat is chosen because it can move along the tension track to meet the tensioning requirements; at the same time, the self-aligning bearing ensures that the conveyor can operate properly even when there is a certain amount of coaxiality error between the two supports. When the conveying equipment uses a double-chain or multiple-chain structure, since the lengths of the various chains cannot be identical, the connection between the sprocket on the driven shaft and the shaft must not rely on keys; instead, the sprocket should be able to move along the shaft in order to reduce the additional tension exerted on the chains. 3. The main body of the conveyor line: The frame is usually constructed by welding steel sections together. Chain conveyor equipment uses a chain as its main working component; the chain serves as the load-bearing element, and since it is a flexible component, the chain in the load-bearing area must be supported by guide rails so that it can function as a rigid structure for bearing loads ； When there are sagging chains at the edges of a structure, due to the significant weight of these chains, it is necessary to design support tracks for those edges in order to reduce the tension at the edges, extend the service life of the chains, and decrease the power requirements of the driving mechanism. Additionally, this is done to prevent interference between the chains and the frame during operation ； Support tracks are often made of wear-resistant and friction-reducing materials with sufficient strength. Due to the polygon effect of chain drives, when chain drives need to be used in stages within a structure (such as in power roller conveyors), the number of teeth on the sprockets at each stage should be the same, so that the transmission ratio between them is 1, thereby preventing crawling. When a machine is composed of two units with roughly identical structures, each unit should be driven by its own drive mechanism; the two units should not be driven by a single drive mechanism, to avoid significant crawling in the machine’s operation due to the polygonal effect of the chains (for example, the upper and lower conveyors in a bridge-type automobile assembly line are both driven by their own separate drive mechanisms). To meet different production rhythms, the operation mode of conveying equipment can be designed as synchronous or asynchronous. By synchronous operation, it is meant that the conveying equipment runs at a certain speed and in a fixed rhythm within a specific speed range ； Asynchronous means that the workpieces on the conveying equipment can be stopped and reset on the conveyor belt according to the requirements of each workstation. When the conveying method is asynchronous, the structural designs of the stopping device and the releasing device after stopping vary; they can be purely mechanical, or they can combine pneumatic or hydraulic systems with electrical components. Regardless of the structural design used, it must be reasonable and reliable, and it must meet the requirements of the product assembly process. This represents a challenge in the design of conveying equipment and constitutes a core technology. 3. Selection of chain specification: For precision roller chains, **standards specify power curves; during design, one can refer to mechanical design manuals and select the appropriate chain specification based on the operating speed and the power transmitted by the chain, in accordance with those power curves. For the selection of chain specifications in other forms, the empirical comparison method is still used at present. The general selection principle nowadays is that the breaking load of the chain should be 5 to 7 times the calculated service load of the chain; for suspension chains, the breaking load should be 7 to 10 times the calculated service load of the chain. 4. Electrical Control: For synchronous conveyors with relatively simple operation requirements, conventional electrical control systems are typically used. The functions of such control systems include speed adjustment, drive protection, overload protection, and limit protection. Asynchronous conveyors are generally controlled by PLCs for process control; when they have multiple control points due to functions such as system grouping, addressing, transmission, protection, and monitoring, computer control is used. When a workshop has multiple conveying devices to form an automated production line, its control is more complex than that of asynchronous conveying devices; in addition to transporting workpieces, it also has various management functions, and computer-based central programming is usually employed. In short, the control system for a chain conveyor should be determined based on the specific operating conditions of the conveyor. There are a wide variety of structural types for chain conveyor equipment, and each one has its own particularities. The control system must be adapted to the functions of the assembly line; this is the main technical issue that needs to be addressed ； The design and selection of reducers, motors, chains, bearing housings, etc., as well as the strength verification calculations for the driving and driven shafts, are the main tasks during the design process ； The drive unit, driven unit, and the main structure of the conveyor belt constitute the core of conveying equipment ； The chain is a key component of the assembly line.