Bulldozers can not turn to troubleshooting skills

A T140 bulldozer in the process of the gradual emergence of steering failure, and finally to the left almost can not turn to the right turn is also difficult, and in the steering engine speed was significantly reduced. It is determined that it is possible that the steering clutch can not be separated, resulting in the steering only when the brake is activated, the engine load is increased and the rotational speed is reduced.
T140 bulldozer steering clutch is wet, multi-chip, spring compression, hydraulic separation of the structure type, the clutch can not be separated should be steering hydraulic system failure. After testing, hydraulic system hydraulic normal, steering valve after the oil leakage. After the steering oil is turned from the steering valve, it shall enter the bearing housing through the tubing, and then enter the piston chamber through the connecting plate to push the piston to move, so that the clutch separation, infer this section of the oil may lead to leakage of the site and the reasons There is damage to the O-ring on the tubing, the rotating seal ring on the connecting plate is worn, the clutch piston seal ring is damaged, and the connecting bolt of the clutch and the connecting plate is loose.
When the clutch was dismantled, it was found that the large nut of the left fixed connecting plate was loosened and the connecting plate mounted on the spline end of the rear axle shaft was easily taken down and the mating surface of the connecting plate and the bearing Have been worn; the right side of the lighter than the left side of the light, and fixed connection plate of the big nut is not loose, the connection plate in the rear axle fixed on the axle, resulting in the removal of large nuts have to use the Rally to unload The bearing on the right side has been worn.
It is assumed that the bearing seat is fixed to the box. When the bulldozer is running, the rear axle shaft drives the connecting plate to rotate. For the left side, due to the loose connection of the connecting plate, the bearing is in contact with the inner surface of the bearing seat during rotation, Side is due to damage to the bearing after the bridge shaft radial run, driven by the connection plate also radial runout, contact with the bearing surface of the surface caused by wear and tear. It is precisely because the connecting plate and the bearing seat produces radial relative movement, while the wear and tear of the pressure oil leakage, resulting in can not turn.
In order to save money, it is decided to repair the wear plate and the bearing seat after wear, and the mating surface of the connecting plate will be cut a little smaller, so that the surface of the mating surface will be flattened. (The amount of cutting should be based on the surface without wear marks). After the car is finished, write down the shaft diameter (assuming D); the bearing seat with the diameter of the diameter of about 10mm, and then in the enlarged hole set a bushing, bushing diameter is less than D, And then the bushing diameter of the car to D +0.5 mm size, even if the connection plate and the bearing surface with a 0.5mm gap. Note: the left and right sides of the connection plate and the bearing seat to match the repair, not interchangeable, the connection plate on the two rotary seal ring has been used, there is a certain wear and tear, slightly reduced outer diameter, the test just Can be used to repair the connection plate and bearing with the installed capacity of the various parts are equipped with a good adjustment, the test machine that the two sides turned to work back to normal, indicating that the fault was excluded.
Disassembly Note:
(1) Remove the connecting plate and the drive wheel, the driven wheel and the final drive flange connecting bolts to turn the track, turn the edge of the split (available external drag bulldozers, the same assembly) Note that all the bolts when assembling To be evenly fastened, can not be missed.
(2) If the main drive bevel gear pair is working properly, it should not be removed at the same time on both sides of the bearing seat, so as not to support the rear axle shaft, the assembly has to adjust the meshing barrier, increase the workload, Side, repair the assembly and then split the other side.
(3) the installation must be connected to the big nut tightened, locked, to avoid loose and cause wear again.
(4) when the assembly should not bolt, wrench and other objects fall into the rear axle box, the first line of a rope can be tied to the wrench, the other end tied bolt, if the slide, can also be used to pull out the rope.