Water lubricated line shaft bearing and lubrication system for a geothermal production pump

摘要

Disclosed is a water lubricated line shaft bearing assembly (10) for a geothermal production pump. The assembly has an outer annular steel shell and an inner layer made of low friction material attached to the outer shell. The inner layer has a non-uniform thickness which is formed with wall portions of increased thickness defining a plurality of shaft engaging portions and has wall portions of reduced thickness defining a plurality of lubricant passages. The shaft engaging portions are capable of being journalled on a line shaft (31) adapted to drive a downhole geothermal production pump. The steel shell is engageable with an inner wall of a lubrication tube (38) vertically extending through a water column (35) through which pumped geothermal fluid (37) is delivered. Lubrication water (39) bled from the pumped geothermal fluid is used to supply lubrication water through the lubricant passages. The steel shell has sufficient compressive strength to withstand the stress imposed by the high rotational speed of the line shaft of the geothermal production pump. The low friction material of the inner liner allows solid debris present or entrained in the lubrication water to slide over the inner line. Solid debris is prevented from accumulating due to the presence of the passages through which the lubrication water flows.