Some methods for Bridge crane parts maintenance

- Jul 14, 2018-

First, the removal of crane parts

(1) Disassemble and inspect hooks, shafts, beams, pulleys, bearings and clean and lubricate. Hooks, beams, pulley shafts, cracks are not allowed, the threaded parts should not be loose, the bearings are intact, the pulleys are turned, and the threads are retracted. Those with knife marks or cracks should be replaced;

(2) Check the wear condition of the dangerous section, and the wear of the dangerous section exceeds 10% of the original height and should be replaced;

(3) Test of hooks, after overhaul, the hooks shall be tested and tested, and suspended at 1.25 times the rated load for 10 minutes. The elastic opening of the hooks shall not exceed 0.25% of the size of the hooks. There shall be no permanent deformation after unloading. And cracks;

(4) Inspection of the board hook. After the board hook is riveted, the gap between the board and the board should not exceed 0.3mm.

Second, the maintenance of the wire rope of the crane parts

(1) Broken wire inspection: 1 wire breakage exceeding 10% of the total number of wires shall be scrapped according to the standard;

(2) Radial wear amount: If the radial wear of the steel wire exceeds 40% of the original diameter, the entire steel wire rope shall be scrapped;

(3) Deformation inspection: the diameter of the wire rope is reduced to 70% of the rope diameter, the rope core is exposed, and the strander should be scrapped for new steel wire;

(4) Lubrication of steel wire rope: Before cleaning, first clean with wire brush, kerosene, etc., and saturate with steel wire rope (Q/SY1152-65) or synthetic graphite calcium-based lubrication (SYA1405-65).

Third, the bridge crane parts of the pulley repair

(1) Disassemble and inspect the pulley block, check the crack, the pulley shaft must not have cracks, the journal should not wear the original diameter of 30%, and the conical degree should not exceed 5%. If it exceeds this value, it should be replaced;

(2) Inspection and repair of the pulley groove, check the groove shape of the pulley with the sample plate, the radial wear should not exceed 30% of the wall thickness, otherwise it should be scrapped. Those who can't exceed the standard can repair it. After the overhaul, the sample should be checked. The bottom and lateral clearance should not exceed 0.5mm. The deviation between the center line of the wheel groove and the center line of the pulley should not exceed 0.2mm. The deviation should not be greater than 1mm;

(3) Inspection of the shaft hole, after overhaul, the shaft hole is allowed to have a defect of not more than 0.25CM2, and the depth should not exceed 4mm;

(4) After assembly and assembly, it should be able to rotate flexibly by hand, and the lateral swing should not exceed D/1000. The nominal diameter of the D-pulley.

Fourth, the crane repair of the drum

(1) Reel rope groove, if the rope groove wear exceeds 2mm, it should be re-made. After overhaul, the rope groove should meet the requirements of the drawings, but the wall thickness of the reel should not be less than 81% of the original thickness;

(2) The surface of the reel, there should be no crack on the surface of the reel, there should be no obvious roundness, and the platen screw should not be loose;

(3) Reel shaft, there shall be no cracks on the reel shaft, and the drawings shall be met after overhaul. When the wear exceeds 5% of the nominal diameter, new parts shall be replaced;

(4) Assembly and installation, the center line of the reel shaft and the support surface of the small frame should be parallel, the deviation should not be larger than 1mm/m, and the deviation of the center line of the two shaft ends after the reel installation should be no more than 0.15mm.

Five, crane parts wheel repair

(1) When the wheel tread wears and the wheel tread wear exceeds 15% of the original thickness, the new part should be replaced. If it does not exceed this value, it can be re-made and heat-treated. The wheel diameter should be within the tolerance range, the surface quenching hardness HB300~500, the thickness of the quenching layer with the wheel diameter greater than Φ400mm should be greater than 20mm; when less than Φ400mm, the quenching layer thickness should not be less than 15mm;

(2) The deviation of the diameter of two mutually matching wheels, the deviation of the active wheel diameter should not exceed 0.1% of the nominal diameter, the driven wheel should not exceed 0.2%, and the diameter deviation of the electric hoist wheel should not exceed 1% of the nominal diameter. The moving wheel should not exceed 0.2%; the diameter deviation of the electric hoist wheel should not exceed 1% of the nominal diameter;

(3) Flange wear and breakage, deformation: the rim wear amount up to 50% of the original thickness or the fracture area exceeding 30mm2 should be scrapped, and the rim thickness bending deformation up to 20% of the original thickness should be scrapped;

(4) Wheel crack: When the wheel finds a crack, it should be scrapped;

(5) Ellipsis of the tread: the ellipse of the wheel tread should be 1mm and should be scrapped;

(6) Wheel group assembly: The installed bridge crane wheel assembly should be flexible to the hand. Several wheels mounted on the same balance frame are in the same vertical plane with a tolerance of 1 mm.

Sixth, the wheel axle and bearing maintenance of crane parts

(1) Inspection of the journal: The ellipticity and conicality of the journal after overhaul shall not exceed 0.03 mm;

(2) Overhaul of crack: Check the shaft with magnetic or ultrasonic flaw detector, there shall be no crack on the shaft, and the scratch depth shall not exceed 0.03mm;

(3) Overhaul of rolling bearings: An axial gap in the range of 0.03~0.18mm is allowed between the inner and outer rings of the tapered roller bearing. The bearing gland adjustment gap should be within the range of 0.5~1.5mm.Kiwicrane company supply end truck,wheel,drive motor,power system and some other crane components for overhead crane.