| 摘要 |
A tractor comprises a tractor module ( 10 ) coupled at opposite ends to a cleaning or inspection module ( 11 ) and a power generation module ( 12 ), the three modules being arranged in line within a pipeline ( 14 ) such that traction elements ( 15 ) on the tractor module ( 10 ) engage the wall of the pipeline ( 14 ). In operation within a pipeline along which fluid is flowing in the direction ( 16 ), drive is imparted to the power generation module ( 12 ) by the fluid flow, and the tractor module ( 10 ) is driven in the direction ( 17 ) by the power generation module ( 12 ) by way of a drive shaft ( 21 ) and appropriate step-down gearing (not shown). A speed governor is used to control the rotational speed of the drive shaft ( 21 ) such that the tractor speed is not directly related to the speed of the fluid flow, and is preferably substantially independent of the speed of the fluid flow. A tractor travelling at a constant and/or controlled speed is found to achieve better cleaining, or to enable more efficient inspections, than a tractor which is propelled along the pipeline at the rate of fluid flow in the pipeline.
|
