With the development of hydraulic technology, hydraulic transmission system is widely used in construction machinery. From a technical point of view, any kind of hydraulic transmission system should meet the requirements of design, simple structure, convenient use and high efficiency. Hydraulic system has a direct impact on the performance of hydraulic engineering machinery, this paper on the use of hydraulic steering system in the common fault diagnosis and exclusion to talk about some understanding and practice.

(1) steering heavy

1) if the steering wheel is heavy and steering without pressure, the steering wheel can be lower, oil viscosity is too large or check valve failure in the valve body. First check the oil level in the tank and hydraulic oil viscosity, if the oil level is lower than the standard height is added hydraulic oil, such as oil viscosity is too large should be replaced with proper viscosity of hydraulic oil, such as oil viscosity normal should disassemble steering device. If the valve body one-way valve ball is lost, into the new ball, if dirt stuck ball should be cleaned, if the check valve sealing strip and the steel ball contact undesirable application ball impact of the sealing is reliable.

2) if the steering wheel light or fast steering wheel heavy, it may be caused by insufficient oil supply. In the oil level height and viscosity suitable premise should check the hydraulic pump is normal, such as low hydraulic pump supply small or pressure should be repaired or replaced.?

3) if the no-load or light load to light and steering heavy for heavy load, may is valve block pressure relief valve below the working pressure of the overflow valve is dirt stuck or spring failure or damage to the sealing ring caused. Should first adjust the relief valve operating pressure, the adjustment is not effective when the decomposition of the relief valve, such as spring failure, seal ring damage should be replaced with new.

4) when the steering wheel when the hydraulic cylinder when the dynamic and irregular sound, it may be the steering system in the air or steering hydraulic cylinder leakage caused by too large. Should open the fuel tank cap to see if there is a bubble in the tank, if there is no leak in the oil tank, and then check the pipeline connection is intact, and the exclusion of the air in the system. If the hydraulic cylinder is still moving, it should check the sealing condition of the piston, replace the seal if necessary.

(2) steering failure

1) when the steering wheel is turned, if it can not automatically return to the neutral position, the pressure drop between the middle position is increased, which may be the steering device positioning spring piece elastic problem or broken. At this point, the steering gear can be decomposed to view the positioning spring pieces, such as the spring piece is in good condition as a result of insufficient elasticity, should be replaced; such as the spring break the piece should be replaced with a new spring piece, is strictly prohibited with other parts replacement.

2) when the steering wheel is turned, the pressure can be increased and even cannot be turned. It is possible that the steering gear drive pin is broken or deformed, and the opening of the transmission rod is broken or deformed. At this time can break down the steering gear to view the transmission pin and the transmission rod, such as transmission pin without breaking to see if its deformation, such as deformation should be replaced or corrected, the transmission rod opening if there is broken should be new.

3) if the steering wheel's rotation or the left and right swing, it is possible that the rotor and the transmission rod are arranged in a wrong position. At this time, the gear can be engaged with the tooth of the gear tooth and the tooth of the spline hole of the rotor on the driving rod to be engaged with the tooth of the spline hole of the rotor.

4) if the mechanical deviation or turn the steering wheel cylinder or slow moving, may is the safety valve of the ball is dirt stuck or the damage of the sealing ring. The steering gear, the safety valve and the sealing ring should be broken down.

(3) the steering wheel can not be automatically back

1) will shift to the crown chakra, engine running at low speed, rotation direction of the disc if the rotation resistance, when the engine flameout, his hands gripping the steering wheel push and pull, if there is no any gap feeling and pull very laborious, explain to the top of the column axial die spool or the steering column and the valve core is not concentric, should be re assembly and adjustment.

2) adjusted if the steering disc are not automatically back in May is the positioning spring pieces are broken or drive pin deformation, should disassemble steering device were examined, such as positioning spring deformation, elastic weakened or broken should be replaced, the drive pin deformation should be corrected or replaced, must not be allowed to replaced by other parts. (4) steering gear oil leakage

1) look at the oil spill traces can be found in the oil spill site. Such as the oil spill site is the tightness of the valve body, a swash plate, a stator and a rear cover combined surface can be used to check the hand joint bolt, if the bolts are loose and tighten no oil leakage fault in this. If the bolt can not loose all the bolts on the rear cover, and then tighten the cross sequence, such as the oil spill does not indicate that the combination of bolts did not tighten in accordance with the provisions of the order.

2) if the bolt according to the prescribed tightening sequence still leak, in conjunction with dirt or joint uneven surface or seal hardening, aging, damage to the surface. At that time, decomposition of steering gear. As with the surface dirt should be cleaned, check the limit bolt gasket, such as uneven should be removed or replaced.?

(5) no manpower steering

1) first check the steering system of the connection pipe is not broken, the joints are loose, if there is a leak in the pipeline rupture or joints loose, should replace the tubing, tighten the joint.

2) if the pipeline well, then the steering hydraulic cylinder tubing joints loose, turning left and right steering wheel, tubing joints without oil outflow, if there is no outflow of oil piping system of the blockage, or the rotor and the stator with axial and radial clearance exceeds the limit, a valve core and a valve cover and the valve body between the radial gap is larger than the allowable range. At that time, remove steering gear and decomposition. Inspection of the components of the clearance and binding surface, such as clearance more than the provisions should be chrome plating polishing repair, such as the surface of a minor scratch