What is the working principle of hydraulic universal testing machine?

Working principle of hydraulic universal testing machine: the hydraulic oil in the oil tank drives the high-pressure gear pump to enter the oil circuit through the motor, flows through the check valve, 10μ high-pressure oil filter, differential valve group and oil delivery valve, and enters the oil cylinder. By manually controlling the opening of the oil delivery valve, the flow into the oil cylinder is controlled to meet the loading requirements. After the test is completed, open the oil return valve to unload and return to the cylinder.

1. Main engine: The main engine consists of a supportable structure with adjustable height (consisting of a frame, a screw and a movable beam), a task cylinder, a piston, a task table, a polished rod and an upper beam. Its task principle is that the high-pressure oil pump supplies oil to the task cylinder. After the piston moves, the task table and the upper beam move laterally, and the task table and the upper beam move upward, so as to carry out experimental stretching or shrinking experiments. The adjustment of experimental space is mainly to make the movable beam rise and fall by the driving mechanism.

2. Piston of the task cylinder of universal testing machine: The piston of the task cylinder and the piston are the main parts of the main engine. The oil cylinder is fixed on the machine base, and there is a ball head between the piston and the task table. When returning, the piston will return by its own weight. The sealing of pressure oil is based on the oil film between the cylinder and the piston, and is guided by the inner and outer surfaces of the cylinder. Due to the self-positioning effect of the ball head, the friction between the cylinder and the piston caused by the lateral force is reduced.

3. Moving beam and driving mechanism: the moving beam is supported on the lead screw through the driving nut, and the lead screw can rotate in both directions, and the lead screw completes its transformation through the driving mechanism installed on the base. The driving mechanism consists of a reduction motor, a sprocket and a chain, and the reduction motor is driven by the sprocket and the chain to rotate synchronously through two lead screws.