The structure of the pressure gauge; the spring tube pr […]
The structure of the pressure gauge; the spring tube pressure gauge is mainly composed of a support with a threaded joint, a spring tube, a tie rod, an adjustment screw, a sector gear, a pinion gear, a hairspring, a pointer, an upper and lower splint, a dial, a watch case, a cover, etc. . The role of the tie rod is to transfer the displacement of the free end of the spring tube to the sector gear. The role of the sector gear is to convert the linear displacement into an angular displacement and transmit it to the pinion gear.
The function of the pinion gear is to drive the coaxial pointer to rotate, indicating the measured pressure value on the dial. The function of the hairspring is to keep the sector gear and the pinion gear in one-way tooth profile contact, eliminate the contact gap between the two gears, and reduce the back and forth. If it is poor, the adjustment screw changes the position of the adjustment screw to change the length of the short arm of the sector gear to achieve the purpose of changing the transmission ratio.
The working principle of the pressure gauge; the spring tube pressure gauge is also called the Bourdon tube pressure gauge. The free end of the spring in the pressure gauge is closed, and it drives the sector gear to rotate through the pull rod. During pressure measurement, the spring tube is deformed under the action of the measured pressure, so the free end of the spring tube is displaced, and the displacement is proportional to the magnitude of the measured pressure.
Deflect the pointer and indicate the pressure value on the dial. If there is atmosphere in the case, the pressure measured by the pressure gauge is positive or negative; if the case is sealed and evacuated, the pressure measured by the pressure gauge is Absolute pressure. When the spring tube pressure gauge is equipped with an isolation device, it can still measure the pressure of high temperature or corrosive, viscous, easily crystallized and dusty media.
In the elastic pressure measuring instruments with high accuracy (such as above 0.25 grade), the elastic element is mostly made of constant elastic alloy or quartz glass. The shaft hole of the transmission mechanism is inlaid with a jewel bearing or a rolling bearing. The scale of the dial is long, some Digital display is also possible.