Mechanical hydraulic system leakage reasons and maintenance
Hydraulic transmission system has small volume, light weight, than the big power, smooth operation, but stepless speed regulation and other advantages, in all kinds of crane widely used. But hydraulic transmission system transmission efficiency of less than other transmission system, easy generation fault and the failure analysis and ruled out more difficult. Therefore, the use of personnel required to have a basic knowledge of the hydraulic system.
Engineering mechanical hydraulic system there are two main leakage, fixed seal leakage and sports seal leakage, fixed seal leakage of the main parts including crock bottom, the joint of the tube fittings etc, sports seal mainly include oil cylinder piston rod parts, multi-channel stem and other parts. From the oil leakage can also be divided into the external leakage and internal leakage and external leakage is mainly refers to the hydraulic oil leaking into the environment from the system, internal leakage is because the high and low voltage side of the existence of the pressure difference and seal failure and other reasons, make the hydraulic oil in the internal system is composed of high voltage side to low voltage side.
Three, influence the causes for the leakage of:
(1) the choice of seals
The reliability of the hydraulic system, to a great extent, depends on the hydraulic system design and seals of the seal of the choice, because design sealing structure choose not reasonable, then choose not orthodox, in design do not consider the hydraulic oil and sealing material compatible type, load conditions, and extreme pressure, working speed, temperature change size, etc. These are in different degree directly or indirectly caused to hydraulic system leaks. In addition, due to the use of mechanical engineering environment with dust and impurities, so in the design, the choice of appropriate to dust seal, avoid dust and dirt into the system damage sealing, oil pollution, which causes the leakage.
(2) other design reason
Design into the movement of the geometry precision and surface roughness is not comprehensive in the design and no connection parts of the strength check, these will be in the work of the mechanical leakage.
(2) manufacturing and assembly factors
(1) manufacturing factors:
All of the hydraulic components and the sealing parts have strict dimension tolerance, surface treatment, surface smoothness and geometrical tolerance requirements, etc. If in the manufacturing process super bad, for example: oil cylinder piston radius, seal groove depth, width, with seals or size of holes or because of the processing problem of tolerance and cause lost round, itself has the burr or hollow point, chromium plated fall off, seals will have deformation, scratch, killed or pressure and fraudulent phenomenon happens that it loses sealing function.
(2) assembly factors:
Hydraulic components in the assembly should put an end to savage operation, if excessive force will make parts deformation, especially with tongbang etc of cylinder block and seal beating flange; Before assembly parts to a careful examination, assembly should dip in a little part of the hydraulic oil, gently pushing, when cleaning application diesel, especially the sealing ring, dustproof circle, o-ring, rubber components, if use gasoline makes its aging lose elasticity, and lose sealing function.
(3) the oil pollution and parts of damage
(1) gas pollution
At atmospheric pressure, hydraulic oil can be dissolved in around 10% of the air, and in the hydraulic system under high pressure, in the oil will dissolve more in the air or gas. Air bubbles formed in the oil, if hydraulic support in the process of operation in a very short time, pressure between high and low voltage in rapid transformation can make the bubbles in the high temperature high pressure produced in low voltage side burst, if hydraulic system components of the surface has sunken point and damage, hydraulic oil will be high speed to wear of the surface elements surface acceleration, leakage.
(2) particle pollution
The hydraulic oil cylinder as some engineering mechanical hydraulic system's main actuators, because working process bare outer environment directly and piston rod in contact, although in orientation set and sealed with dust circle, but also unavoidably will dust, dirt into hydraulic system, accelerate the sealing parts and the piston rod and scratch and wear, and cause leakage, particle pollution for hydraulic components damage the fastest factors.
(3) parts damage
Seal is by oil resistant rubber and materials, the use of for a long time, chap, aging happened damage can cause system leaks. If parts in the process of operation by the collision and damage, the predictable seal components, and cause leakage.