The structural principle of the hydraulic diaphragm metering pump is composed of an electric motor transmission mechanism, a hydraulic system, etc.
transmission mechanism
1. The stroke adjustment mechanism consists of a crankshaft, an eccentric wheel, an adjusting nut, an adjusting screw, an adjusting handwheel (handle), a dial (pointer), and a ruler. The relative stroke of the plunger is achieved by changing the eccentricity.
2. The motor power is transmitted to the worm gear and worm wheel to achieve deceleration rotation, which drives the crankshaft and connecting rod mechanism to make reciprocating motion and drives the plunger to generate hydraulic pressure.
hydraulic system
The plunger at the hydraulic end of the hydraulic diaphragm metering pump is driven by the reciprocating motion of the crank connecting rod mechanism at the transmission end. The plunger moves back and forth in the hydraulic chamber, causing pressure changes in the hydraulic oil and causing hydraulic diaphragm type deflection displacement to transport the medium. The relative stability of the hydraulic oil volume in the hydraulic chamber is maintained by the three width function.
2. The hydraulic system of the hydraulic diaphragm metering pump consists of a plunger, cylinder body, cylinder head, inlet and outlet widths, hydraulic diaphragm type, and three widths (i.e., relief overload width, limit width, compensation width). In work, hydraulic oil and medium are separated by a diaphragm, so hydraulic diaphragm metering pumps have the advantage of no leakage.
3. The overload width automatically discharges the gas entering the hydraulic chamber from the hydraulic oil, ensuring smooth operation and avoiding overpressure caused by excessive hydraulic oil or blocked discharge pipelines, thus achieving the purpose of protection. The limit compensation device is driven by a hydraulic diaphragm to open the limit width, and the oil volume is replenished at any time according to the vacuum degree in the hydraulic chamber to ensure that the hydraulic oil in the hydraulic chamber is full.
assembly drawing

Pump installation
1. The pump should be installed on mixed soil at a height of 300-500 millimeters above the ground, and the pump should be calibrated horizontally; When installing multiple pumps, attention should be paid to using the phase to phase coupling of the pump as the calibration reference, and the concentricity deviation should not exceed 0.15 millimeters (elastic coupling), and the steel coupling should be within 0.05 millimeters;
2. Install the pump on a sturdy foundation 200-300 dishes above the medicine tank and install it horizontally.
3. There should be no sharp bends (not greater than 90 °) on the suction and discharge pipelines, and bending and resistance increasing components in the pipelines should be minimized as much as possible.
4. Do not install the pump and medicine tank in areas directly exposed to sunlight.
5. If the medicine tank needs to be replenished with medication and maintained for inspection, please place it in a spacious area.
6. Do not install in areas that are prone to moisture or corrosive gases.
7. The temperature around the pump installation should be between -20~+40 ℃, and it should be used at an altitude of 1000M or below.
Pipeline installation
1. The diameter of the suction pipe should not be less than the suction wide diameter of the pump, and the length of the suction pipe should be shortened as much as possible, usually 2-3 meters; If it is necessary to increase the length, it should be appropriately lengthened, but the length should not exceed 5 meters (but the suction time of the liquid during startup is relatively prolonged).
2. The pipeline connected to the suction and discharge flange cannot be forcibly combined to increase the load on the pump, and the weight of the pipeline and the flange should not be borne by the pump and the suction and discharge flange. After the installation of the pipeline, the pipe fittings should be supported and fixed properly.
The increase in pipeline flux caused by special liquids
To ensure the safe operation of the pump and the safety of the pipeline system, a safety buffer should be installed on the discharge pipeline. If it is necessary to reduce the pulse of the transported liquid, a buffer can be installed near the pump discharge pipeline.
2. For the transportation of suspensions and media that are prone to sedimentation, wide doors and tees should be added near the suction and discharge of the pump, so that the cylinder can be flushed without disconnecting the pipeline when the pump is stopped.
Installation specifications
Other technical requirements for pump installation shall comply with the relevant provisions of the "Construction and Acceptance Specification for Mechanical Equipment Installation Work" TJ231 (V) -78- Pump Installation.