Air sampling pump operation precautions

Air sampling pump structure features:

The pump body includes a motor. The motor we use is an eccentric motor. The working principle of the eccentric motor is that the motor drives the eccentric to rotate, and the air diaphragm inside the pump is reciprocated by a mechanical device to compress the air in the fixed volume pump chamber. Stretching to form a vacuum (negative pressure), creating a pressure difference with the outside atmospheric pressure at the inlet of the pump. Under the effect of pressure difference, the gas is sucked into the pump chamber, and then discharged from the exhaust port. The flow rate of the inhaled gas depends on the motor speed. To control the speed, install a pressure sensor at the outlet pipe to sense the pressure of the trachea. The rotating shaft of the motor drives the eccentric to rotate at a constant speed. The greater the eccentricity is, the larger the stroke of the pump is, and the more gas is pumped each time, the larger the starting torque is. Therefore, the right motor and eccentric distance must be found to achieve the minimum flow velocity. With the highest flow rate. According to the parameters of the motor, speed, torque, voltage select the motor. The model of the motor we use is 236661, 20W and 4660rpm at 12V. The eccentric distance used for the eccentric is 0.8mm, 1.0mm, 1.5mm, 1.6mm, 2.5mm.

In order to avoid that the motor rotates too fast, it is possible to idling. Turn the shaft of the motor into a gap and fix the rotating shaft on the eccentric wheel to ensure that the motor drives the eccentric wheel to rotate together, and then fix the bearing that drives the pump diaphragm up and down on both sides. On the eccentric.

Air sampling pump operation Note:

(1) When mounting the bearing, be careful to hold it flat, press it, and then find a platform. When the bearing is mounted on the eccentric, it is necessary to pay attention to the bearing is placed against, to find a good position, but also leveling, so that the center of the two bearings (in a straight line). There are screws from the side to stay out, in the above, the following is the two relative bearings, then you should use the vernier caliper to measure the total diameter, and then measure the radius of the two sides, to see if the center of the bearing is not found, adjust well Finally, use plastic to fix the bearing.

(2) When placing the eccentric on the rod of the motor (to put the bearing rod on both sides), you can see that the rod has a sloping table, and then align the table with the self-screw on the eccentric. Screw it in and fix it.

(3) The center is accurate, and then put the flat cover on both sides to the bearing rod, pay attention to flatten it again, and attach the eccentric wheel, so the bearing rod is moving back and forth, so don't put it on Under the pressure, it is easy to make the center of the two bearings deviate. All the black sheets on the two heads must be mounted on the bearing, and then be fixed on the bearing with a head support. Both ends are fixed in this way to prevent the rotation axis of the motor from being Pressed and damaged the motor.

(4) Above the flat cover, put the adhesive film and the aluminum platform. After screwing it in, place the edge of the film along the edge of the mold so as to avoid pressing or sealing.

Then install the air outlet and top cover. Air sampling pump Note:

(1) The inlet and outlet caps are equipped with two small membranes, one for air intake and one for air outlet. Press the middle of the air outlet. Press it flat and press it tightly. There should be no support, otherwise it will leak. Re-buffering film, pay attention to the size of the cavity, do not anti-anti. The buffer membrane should also be pressed from the middle, and it should be tight and not leaking.

(2) The evacuation side chamber is larger than the exhaust side, and the shell is also covered with a membrane. This chamber and membrane of the shell act as a buffering function. Once the pumping or exhausting is temporarily blocked, when it is not open, it will Can help buffer (that is, let the pressure alarm have a range, not fixed, change the value to alarm, and its buffer can be compensated in the subsequent suction or exhaust).

The lids on both sides are the same, but the isolation layer is not the same. At one end there is a long exhaust port and a short exhaust port; the other end is not. Pay attention to the isolation layer and the cover when installing, because it must be aligned and re-aligned. Otherwise, it will not achieve the effect of isolation. Before closing, make sure that there are two black rubber gaskets on both sides. In the absence of this rubber washer, it is easy to spring open, so after hanging the screw, press the side of the washer tightly by hand and then tighten the screw.

Tighten the screws evenly, and finally tighten them to see if the screwed cover is flat and there is still a leak. But note that it is best not to screw it back and twist it back, which can easily cause air leakage.

(3) Sealing the lid and the barrier layer: Careful attention must be paid to the seal.

The sealing film on the lid first goes up the middle rib, then goes up to the ribs on both sides of it. After that, the upper and lower ribs are perpendicular to the center, and it is also in line with the principle of rushing from the middle to both sides.

The membranes of the isolation layer are two small rectangular membranes, one surface deep (as small as possible, no flash film, to avoid air leakage), one light, are fixed by three rods. First put the film on the rod, then use a word screwdriver to press both sides of the rod from the middle to both sides, let the film cover in, then follow the thick middle of the pressure, and then look in the light to see if there is no fit. A tight place (pressure changes at the same time).