Design of grease lubrication system

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Design of grease lubrication systems A grease (dry oil) lubrication system is a lubrication system that uses grease as the lubricant. 1. Classification of centralized grease (dry oil) lubrication systems: In various mechanical devices, in addition to the method of individual, dispersed lubrication (that is, manually adding grease to the lubrication points using grease guns or applicators on a regular basis), for large machines with numerous lubrication points, or in cases where it is not possible to stop the machine to add grease, or where manual greasing is dangerous or difficult (such as in situations with many lubrication points at high temperatures, making it impossible to reach those points quickly enough), a centralized dry oil lubrication system must be used to apply grease regularly for lubrication. This lubrication system is generally a fully consumptive system that is not recycled. A centralized grease lubrication system uses appropriate pump pressure to deliver grease to the lubrication points at regular intervals and in fixed quantities, thereby ensuring a reliable and sufficient oil film between all the friction surfaces of the equipment and maintaining its proper operation over time. Generally, pumps equipped with large containers (such as grease cartridges) are placed near the lubrication points. A pump is used to pressurize the grease coming from the container, forcing it through the delivery pipelines into the dosing devices in the system (such as dose valves, etc.). Then, the amount of lubricant required is measured in this device, and it is pressed into the lubrication points in sequence to provide lubrication. 1) Manual dry oil centralized lubrication system: In single machines with a small number of lubrication points and that do not require frequent lubrication using thin oil, manual dry oil lubrication stations are widely used for applying grease. 2) Automatic dry oil centralized lubrication system: The automatic dry oil centralized lubrication system consists of an automatic (pneumatic or electric) dry oil lubrication station, two oil feeders connected by oil delivery lines, relevant electrical devices, control and measurement instruments, etc. It is divided into 4 types. (1) Direct system: The direct system uses the pump’s stroke to directly control the amount of grease supplied. Its main control elements are cams and reciprocating pistons. This pump can lubricate more than 12 lubrication points per stroke. However, the manufacturing of such pumps is more complex than that of the valves in indirect systems. (2) Outflow (end-flow) type automatic dry oil centralized lubrication system. The outflow type automatic dry oil centralized lubrication system can supply more lubrication points and cover a wider range of locations, especially in machines with an elongated shape (such as the roller tables in steel rolling equipment). (3) Circular (loop-type) automatic dry oil centralized lubrication system. The circular automatic dry oil centralized lubrication system consists of an electric dry oil station equipped with a hydraulic directional control valve, main oil supply pipes that form the oil supply loop, and oil feeders. It belongs to dual-line fat supply. This type of ring-shaped centralized dry oil lubrication system is generally used in areas where machines are densely packed and there are a large number of lubrication points. (4) Pneumatic dry oil centralized lubrication system: The pneumatic dry oil centralized lubrication system mainly consists of a pneumatic dry oil station, main oil delivery pipes, oil feeders, etc. It can be arranged in a flow-through configuration or a circular configuration as needed. 2. Design of the dry oil centralized lubrication system 1) Design steps (1) Calculate the amount of grease required, and select the type and size of the grease feeder. (2) Determine the lubrication schedule – the lubrication interval or the operating cycle time of the dry oil station (the time the oil pump is in operation plus the downtime). This is usually determined by the characteristics of the friction surfaces and the working conditions (such as operating temperature, dust levels, exposure to corrosive substances, etc.). (3) Selecting the type, size, and quantity of lubrication stations: When choosing lubrication stations, the following factors should be considered: a. The number of lubrication points. b. Distribution of machine lubrication points. c. The total volume of grease, including the total volume of the grease feeder and the total volume of the pipes. d. The extension length of the pipeline (main fat transport pipe). 2) Determination of the capacity of the automatic dry oil centralized lubrication station. 3) Calculate the pressure loss in the fat transfer pipeline