1. Working principle of hydraulic transmission Hydraulic transmission principle: oil is used as the working medium, and power is transmitted through the pressure inside the oil.
（1）Execution part - converts the oil pressure energy input by the hydraulic pump into mechanical energy that drives the working mechanism. For example: various hydraulic cylinders and hydraulic motors.
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（2）Power part - converts the mechanical energy of the prime mover into the pressure energy (potential energy) of the oil. For example: various hydraulic pumps.
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（3）Auxiliary part - connects the first three parts together to form a system, which plays the roles of oil storage, filtration, measurement and sealing. For example: soft and hard pipelines, joints, fuel tanks, oil filters, accumulators, seals and display instruments, etc.
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（4）Control section - used to control and regulate the pressure, flow and flow direction of oil. For example: various pressure control valves, flow control valves.
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2. Working principle of hydraulic cylinder:
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First understand the five most basic components:
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（1） Exhaust device
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（2）buffer device
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（3）Pistons and piston rods
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（4）Sealing device
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（5）Cylinder barrel and cylinder head
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? ? The working principle of each type of cylinder is similar. Take a manual jack as an example. Its original work (the jack is actually the simplest oil cylinder) is to manually pressurize the cylinder (hydraulic hand pump) to allow hydraulic oil to enter through a single valve. At this time, the hydraulic oil entering the cylinder cannot go back due to the single valve, forcing the cylinder rod upward. Then, the hydraulic oil continues to enter the hydraulic cylinder during work, and it continues to rise in this way. When it wants to fall, open the hydraulic valve. , allowing the hydraulic oil to return to the tank.
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