# US 2020/0399972 A1 · Wellhead sealing device of sucker-rod pumping machine

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- Number: US 2020/0399972 A1
- Document ID: US20200399972A1
- Status: Published application
- Kind: A1
- Application number: 17/007,414
- Filed: 2020-08-31
- Published: 2020-12-24
- Earliest claimed: 2016-01-08
- Inventors: Licheng YU; Kao SI
- Web page: https://patentgrep.com/patent/US20200399972A1

## CPC

- E21B 33/06: Blow-out preventers {, i.e. apparatus closing around a drill pipe, e.g. annular blow-out preventers (rotating blow-out preventers E21B33/085)}
- E21B 33/03: Well heads; Setting-up thereof
- E21B 33/04: Casing heads; Suspending casings or tubings in well heads
- E21B 33/085: {Rotatable packing means, e.g. rotating blow-out preventers}
- E21B 43/126: {Adaptations of down-hole pump systems powered by drives outside the borehole, e.g. by a rotary or oscillating drive (powered by fluid E21B43/129)}
- E21B 43/127: {Adaptations of walking-beam pump systems}
- F16J 15/002: {comprising at least two sealings in succession (F16J15/162, F16J15/40 take precedence)}
- F16J 15/187: {Self-aligning stuffing-boxes}
- F16N 15/00: Lubrication with substances other than oil or grease; Lubrication characterised by the use of particular lubricants in particular apparatus or conditions (F16N17/00 takes precedence; lubricating compositions, selection of particular substances as lubricants in general C10M)
- F16N 11/04: Spring-loaded devices
- E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- F16J: PISTONS {(specially adapted for dampers F16F9/32)}; CYLINDERS; SEALINGS
- F16N: LUBRICATING

## 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.

## Claims

### Claim 1

A polished rod sealing device for an oil pumping machine, comprising a built-in stuffing box, wherein the built-in stuffing box is arranged inside an oil pipe enlargement press cap and can be used to seal the polished rod of the oil pumping machine.

### Claim 2 (depends on 1)

The polished rod sealing device for an oil pumping machine according to claim 1, wherein comprising: an oil pipe enlargement base, an oil pipe enlargement press cap, a built-in stuffing box, a first flexible connection unit, and a second flexible connection unit, wherein the built-in stuffing box is built into the oil pipe, the bottom of the built-in stuffing box is connected to the oil pipe enlargement base by the first flexible connection unit, the top of the built-in stuffing box is connected to the oil pipe enlargement press cap by the second flexible connection unit, and the oil pipe enlargement press cap is connected with the oil pipe enlargement base by a threaded connection.

### Claim 3 (depends on 1)

The polished rod sealing device for an oil pumping machine according to claim 1, wherein the built-in stuffing box comprises: a stuffing box body, a press ring, a press ring liner, a gasket and a gasket liner.

### Claim 4 (depends on 3)

The polished rod sealing device for an oil pumping machine according to claim 3, wherein the built-in stuffing box is mounted in the oil pipe, the stuffing box body of the built-in stuffing box doesn't contact with the oil pipe enlargement press cap, and there is a space enough for radial movement between the stuffing box body of the built-in stuffing box and the oil pipe enlargement press cap; during the operation of the oil pumping machine, the built-in stuffing box moves along with the polished rod and produces corresponding radial displacement and angular displacement under the driving effect of the polished rod, so that the stuffing box body, a sealing packing, and the polished rod are coaxial dynamically, and thereby eccentric wear of the sealing packing resulted from the polished rod is prevented.

### Claim 5 (depends on 1)

The polished rod sealing device for an oil pumping machine according to claim 1, further comprising: a solid lubricator, which is arranged at the top of the oil pipe enlargement press cap and has a solid lubricating material storage chamber, and a solid lubricating material stored in the solid lubricator comprises but is not limited to solid lubricant, polished rod preservative and sealing packing healant.

### Claim 6 (depends on 5)

The polished rod sealing device for an oil pumping machine according to claim 5, wherein the solid lubricator comprises: the oil pipe enlargement press cap, a top cover, a handle, holding slide plates, a snap ring, a pushing column, and a pushing ring, and is provided with a baffle plate and fastening bolts for assembling the holding slide plates.