The invention provides a device and method for measuring a small
diameter of a Monod drilling tool / pump
stator liner inner chamber, belonging to the technical field of measurement of the small
diameter of a Monod drilling tool / pump
stator liner inner chamber for
oil drilling. The device for measuring the small
diameter provided by the invention comprises a spring, a floating support, a probe, a fixed
pulley, an inner-diameter measuring rod, a pull wire, a pull wire control gate, a fixed support, a shell, a digital display
measuring instrument and the like; when the device is used for measuring the small diameter, the pull wire control gate is pulled tightly so that the floating support is contracted; the device is placed in the liner inner chamber; the pull wire control gate is released; two support points of the fixed support with the length between one lead and two leads of a
stator and a
support point of the floating support are used for supporting and locating; the probe senses the measuring, and transmits the sense to the digital display
measuring instrument via the inner-diameter measuring rod; and the digital display
measuring instrument is used for measuring and storing the small diameter data of the stator liner. The technology provided by the invention is accurate in locating, high in measuring precision, convenient in use, and capable of improving the matching precision of the Monod drilling tool / pump stator and rotor, thereby promoting the scientific design and use of a Monod drilling tool / pump.