Abstract: A polished rod sealing device for an oil pumping machine includes a built-in stuffing box. The built-in stuffing box is arranged inside oil pipe enlargement press cap and can seal the polished rod of the oil pumping machine. The sealing device maintains dynamic coaxiality between the polished rod and the stuffing box, and reduces eccentric wear of the sealing packing resulted from the polished rod. The sealing device also provides lubrication between the polished rod and the sealing packing.

Abstract: A polished rod sealing device for an oil pumping machine includes a built-in stuffing box. The built-in stuffing box is arranged inside oil pipe enlargement press cap and can seal the polished rod of the oil pumping machine. The sealing device maintains dynamic coaxiality between the polished rod and the stuffing box, and reduces eccentric wear of the sealing packing resulted from the polished rod. The sealing device also provides lubrication between the polished rod and the sealing packing.

Abstract: Provided is a wellhead sealing device of a sucker-rod pumping machine, including a flexible connection unit, and further including a blowout prevention unit, a closing unit, a declination rectification unit and a lubrication unit, wherein the flexible connection unit is arranged between a wellhead and a packing box, and includes a lower flexible sealing sleeve (37), a lower flexible sealing sleeve housing (12), a sealing steel ring (11) and an upper flexible sealing sleeve (10). Portions above the flexible connection unit follow integrally a polished rod (7) constantly to swing, such that a packing (9) is dynamically coaxial with the polished rod (7) and the problem of eccentric wear of the packing can be completely solved. Furthermore, the device can also solve the problems of static coaxiality and lubrication between the polished rod (7) and the packing (9), as well as the problem of blowout prevention when the polished rod (7) is broken off.

Abstract: Provided is a wellhead sealing device of a sucker-rod pumping machine, including a flexible connection unit, and further including a blowout prevention unit, a closing unit, a declination rectification unit and a lubrication unit, wherein the flexible connection unit is arranged between a wellhead and a packing box, and includes a lower flexible sealing sleeve (37), a lower flexible sealing sleeve housing (12), a sealing steel ring (11) and an upper flexible sealing sleeve (10). Portions above the flexible connection unit follow integrally a polished rod (7) constantly to swing, such that a packing (9) is dynamically coaxial with the polished rod (7) and the problem of eccentric wear of the packing can be completely solved. Furthermore, the device can also solve the problems of static coaxiality and lubrication between the polished rod (7) and the packing (9), as well as the problem of blowout prevention when the polished rod (7) is broken off.