Maintenance

date：2019-11-20   

&The maintenance of the screw drilling tools can be divided into field maintenance and workshop maintenance. In principle, every time the drilling tools run into the well, they need to be overhauled. Before the maintenance of the screw drilling tool, the structure of the screw drilling tool shall be fully understood and disassembled in accordance with the order and requirements; the shell (except the connection between the bypass valve and the motor) and the main internal connection parts of the screw drilling tool shall be coated with anaerobic rubber, before the shackle, it shall be heated to 300 ℃ with a blowtorch before disassembly, and then the thread shall be cleaned at the same time. When the lower thread of the stator is disassembled, attention shall be paid to protecting the stator rubber to prevent the rubber from heating and aging. During assembly, all internal and external threads need to be washed with alkyd diluent or acetone first, and then coated with anaerobic adhesive to tighten to prevent tripping.
&On site maintenance: < br / > &1. After removing the drill bit, flush the drilling tool by-pass valve body with clean water, and move up and down the movable valve core without blocking.
&2. Flush the screw drill with clean water from the internal thread of the spindle joint, and then level it; if it is not used for a long time, it is recommended to inject a small amount of mineral oil into the drill to prevent corrosion and sunlight. Do not inject diesel oil.
&The content of workshop maintenance includes the following items: & nbsp; < br / > &Inspection of axial displacement of thrust bearing &Nbsp; & nbsp; & nbsp; & nbsp; a) lift the drilling tool vertically and measure the clearance between the lower end face of the lower bearing housing and the transmission shaft, ll; < br / > &Nbsp; & nbsp; & nbsp; & nbsp; b) put the drilling tool upright on the ground, compress the thrust bearing with the weight of the drilling tool itself, and measure the clearance dimension L2 between the lower end face of the lower bearing shell and the transmission; < br / > &Calculate the axial displacement of thrust bearing: l = L1-L2: when the displacement l exceeds the specified range (see the table below), the thrust bearing shall be replaced.
&3. Maintenance of motor assembly < br / > &After disassembling the motor and cleaning, check the rotor and stator.
&No obvious cracks, degumming and other defects are allowed in the stator rubber, and there shall be no rust, bruise and thread damage at both ends of the stator.
&The rotor surface shall be smooth without erosion, corrosion, coating peeling, groove and other damages, otherwise it shall be replaced.
&After inspection, install the rotor into the stator, lift the motor and fill it with clean water for static sealing test. The leakage of drilling tools with diameter above 165 shall be less than 13L / min, and that of drilling tools with diameter below 165 shall be less than 7L / min, and the motor shall be replaced if it exceeds this requirement. After the experiment, pull out the rotor, dry the water, grease the rotor surface and install it into the stator for assembly. If possible, ground hydraulic motor test or complete machine test shall be carried out.
&4. Maintenance of cardan shaft: < br / > &Petal type cardan shaft: the supporting part shall not be deformed and excessively worn, and the petal gap shall not exceed a certain range and the defects affecting the strength exist. When the petal gap exceeds the value in the table below, it shall be replaced in principle.
Model of screw drill

Flap gap (mm)
5（7）（9）LZ95/102	6
5LZ120	6
5LZ165/5(9)172	10
5(9)LZ197/203	12
5LZ215	12
5(9)LZ44	12

5. Radial bearing: < br / > &In principle, the radial bearing shall be replaced with a new one in case of any crack, falling off of cemented carbide block or clearance of more than 1mm.
&In principle, the surface of the main shaft shall be free of serious defects after use. In principle, it shall be used after re inspection.