초록 ▼

A seal section for a submersible well pump assembly has a housing for connection between a pump and a motor. A central radial bearing support rotatably supports a drive shaft and defines upper and lower chambers in the housing. A well fluid passageway leads from an exterior portion of the housing to

A seal section for a submersible well pump assembly has a housing for connection between a pump and a motor. A central radial bearing support rotatably supports a drive shaft and defines upper and lower chambers in the housing. A well fluid passageway leads from an exterior portion of the housing to the upper chamber. Upper and lower isolation tubes extend around the shaft within the upper and lower chambers, defining an annular passage for fluid communication with lubricant contained in the motor. A bladder surrounds the upper isolation tube for separating lubricant from well fluid in the upper chamber. A labyrinth tube within the bladder has an upper end in fluid communication with a labyrinth port leading through the upper isolation tube and a lower end in fluid communication with the lower chamber.

대표청구항 ▼

The invention claimed is: 1. A seal section for a submersible well pump assembly, comprising: a housing for connection between a pump and a motor of a submersible well pump assembly; a rotatable shaft extending through housing for transmitting rotational motion from the motor to the pump; a central

The invention claimed is: 1. A seal section for a submersible well pump assembly, comprising: a housing for connection between a pump and a motor of a submersible well pump assembly; a rotatable shaft extending through housing for transmitting rotational motion from the motor to the pump; a central radial bearing support that rotatably supports the shaft and which defines upper and lower chambers in the housing; a well fluid passageway leading from an exterior portion of the housing to the upper chamber; upper and lower isolation tubes extending around the shaft within the upper and lower chambers, respectively, each of the isolation tubes having an inner diameter larger than the shaft, defining an annular passage for fluid communication with lubricant contained in the motor; a bladder surrounding the upper isolation tube in the upper chamber for separating lubricant within the bladder from well fluid in the upper chamber on the exterior of the bladder; and a labyrinth tube within the bladder and having an upper end in fluid communication with a labyrinth port leading through the upper isolation tube near its upper end to the annular passage, the labyrinth tube having a lower end in fluid communication with the lower chamber. 2. The seal section according to claim 1, further comprising: upper and lower adapters for connection to the pump and to the motor, respectively; a thrust bearing assembly mounted in the housing below the lower chamber above the lower adapter; and the housing comprises a single cylindrical sleeve extending from the lower adapter to the upper adapter. 3. The seal section according to claim 1, further comprising: a bladder communication port in a sidewall of the upper isolation tube within the bladder for communicating lubricant in the annular passage with the interior of the bladder. 4. The seal section according to claim 1, further comprising: an upper adapter secured to an upper end of the housing for connection to the pump, the upper adapter having a shaft passage through which the shaft extends; a seal base stationarily mounted in the shaft passage of the upper adapter; a spring-biased rotary seal member connected to the shaft and in rotational, sliding engagement with the seal base; and an oil seal mounted between the shaft and the upper adapter below the seal base for preventing any well fluid that leaks past the seal base from flowing downward into the annular passage in the upper isolation tube. 5. The seal section according to claim 1, further comprising: an upper adapter secured to an upper end of the housing for connection to the pump, the upper adapter having a shaft passage through which the shaft extends; a bladder retainer between an upper end of the bladder and the upper isolation tube for sealingly securing the upper end of the bladder to an upper end of the upper isolation tube; and wherein the bladder retainer stabs sealingly into a lower end of the shaft passage in the upper adapter. 6. A seal section for a submersible well pump assembly, comprising: upper and lower adapters for connection to a pump and to a motor, respectively of a submersible well pump assembly; a single continuous sleeve extending from the lower to the upper adapter; a rotatable shaft extending through the upper and lower adapters and the sleeve for transmitting rotational motion from the motor to the pump; a thrust bearing assembly mounted in the sleeve above the lower adapter for adsorbing downthrust on the shaft; a lower radial bearing support that rotatably supports the shaft above the thrust bearing, the lower radial bearing support having a seal that seals to an inner diameter of the sleeve, the lower radial bearing support having a maximum outer diameter less than the inner diameter of the sleeve so that the entire lower radial bearing support fits within the sleeve; a central radial bearing support that rotatably supports the shaft above the lower radial bearing support, the central radial bearing support having a seal that seals to the inner diameter of the sleeve, defining upper and lower chambers in the sleeve, the central radial bearing support having a maximum outer diameter less than the inner diameter of the sleeve so that the entire central radial bearing support fits within the sleeve; a well fluid passageway leading from an exterior portion of the sleeve to the upper chamber; and upper and lower isolation tubes extending around the shaft within the upper and lower chambers, respectively, each of the isolation tubes having an inner diameter larger than the shaft, defining an annular passage for fluid communication with lubricant contained in the motor, the upper isolation tube being connected between the central radial bearing support and the upper adapter, the lower isolation tube being connected between the central radial bearing support and the lower radial bearing support. 7. The seal section according to claim 6, further comprising: a bladder located within the upper chamber, the bladder having an upper end connected to the upper adapter and a lower end connected to the central radial bearing support; and a labyrinth tube having an upper end connected to a port in the upper isolation tube within the bladder and a lower end communicating with the lower chamber through a communication passage in the central radial bearing support. 8. The seal section according to claim 6, further comprising: a seal base stationarily mounted in a shaft passage of the upper adapter; a spring-biased rotary seal member connected to the shaft and in rotational, sliding engagement with the seal base; and an oil seal mounted between the shaft and the upper adapter within the shaft passage and below the seal base for preventing any well fluid that leaks past the seal base from flowing downward into the annular passage in the upper isolation tube. 9. The seal section according to claim 6, wherein the lower radial bearing support, central radial bearing support and upper and lower isolation tubes are insertable as a unit into the sleeve. 10. A seal section for a submersible well pump assembly, comprising: a housing for connection between a pump and a motor of a submersible well pump assembly; a rotatable shaft extending through housing for transmitting rotational motion from the motor to the pump; a central radial bearing support within the housing that rotatably supports the shaft and which defines upper and lower chambers in the housing; upper and lower isolation tubes extending around the shaft within the upper and lower chambers, respectively, each of the isolation tubes having an inner diameter larger than the shaft, defining an annular passage for fluid communication with lubricant contained in the motor; a bladder surrounding the upper isolation tube in the upper chamber; a bladder communication port in a sidewall of the upper isolation tube within the bladder for communicating lubricant in the annular passage with the interior of the bladder; and a labyrinth tube within the bladder and having an upper end in fluid communication with a labyrinth port in the sidewall of the upper isolation tube, the labyrinth tube having a lower end in fluid communication with the lower chamber. 11. The seal section according to claim 10, wherein the housing comprises a single sleeve. 12. The seal section according to claim 10, wherein the central radial bearing support is located entirely within the housing and has a seal on its outer diameter that sealingly engages an inner diameter of the housing. 13. The seal section according to claim 10, wherein the central radial bearing support has a labyrinth tube passage extending between the upper and lower chambers, and the lower end of the labyrinth tube extends sealingly into an upper end of the labyrinth tube passage. 14. The seal section according to claim 10, further comprising: a lower radial bearing support within the housing, the lower radial bearing support and the central radial bearing support each having a shaft passage through which the shaft extends; the lower isolation tube having lower and upper ends that sealingly engage the shaft passages in the lower radial bearing support and the central radial bearing support; and wherein the lower and central radial bearing supports, the lower and upper isolation tubes, and the bladder define a subassembly that is insertable as a unit into the housing. 15. The seal section according to claim 10, further comprising: an upper adapter that secures to an upper end of the housing for connecting the housing to the pump, the upper adapter having a shaft passage through which the shaft extends; a bladder retainer sealingly securing an upper end of the bladder to an upper end of the upper isolation tube; and wherein the bladder retainer stabs sealingly into a lower end of the shaft passage in the upper adapter. 16. The seal section according to claim 10, further comprising: an upper adapter that secures to an upper end of the housing for connecting the housing to the pump, the upper adapter having a shaft passage through which the shaft extends; a seal base stationarily mounted in the shaft passage of the upper adapter; a spring-biased rotary seal member connected to the shaft and in rotational, sliding engagement with the seal base; and an oil seal mounted between the shaft and the upper adapter within the shaft passage and below the seal base for preventing any well fluid that leaks past the seal base from flowing downward into the annular passage in the upper isolation tube.