The three leakage of diesel engine, especially the leakage of engine oil, is a common phenomenon. It not only seriously affects the appearance of the machine clean, increase oil consumption, speed up the wear of parts, but also prone to burning tile, holding shafts and other major mechanical accidents. Oil leakage can be divided into two categories, one is the dynamic contact surface leakage, the other is the static joint leakage.
I. the oil leakage on the moving contact surface
1., the dynamic contact surface seal is mainly the oil seal function, the oil seal itself quality is good or bad, directly affects the oil seal to be good or bad. Therefore, the installation of the oil seal, rubber lip edge should be strictly checked, not allowed to incomplete, aging or incision defects. When tapping the oil seal, it should be applied evenly at the shoulder of the skeleton with the outer diameter, so as to guarantee the assembly quality.
2. diesel engine in operation, high-speed rotating shaft oil seal and static constant contact, friction, and wear speed and axle surface roughness, hardness, shaft seal surface eccentricity has a close relationship, therefore, installation of oil seal shaft neck surface roughness of 1.6 ~ 1.4, hardness HRC45-60 the eccentricity of the sealing surface, generally not more than 0.025mm axis, with the increase of rotational speed, eccentricity allows but also reduce, otherwise easy to produce oil.
The size of the 3. shaft and the oil seal will affect the sealing performance of the oil seal. If the shaft size is too large, although it can guarantee the sealing, but easy to make oil seals produce early wear, greatly shorten the service life.
4., the installation of Baotou North Ben heavy truck parts, oil seals must pay attention to cleanliness. The service life of the oil seal is closely related to the oil leakage. If the installation is mixed with mechanical impurities, it will enter the surface of the oil seal and the shaft neck, causing abrasive wear, and accelerating the wear rate of the journal and oil seal. In addition, impurities are mixed between the shaft neck and the surface of the oil seal, so that the oil seal is not easy to seal, and the oil leakage is easy to occur.
5. installation of Baotou North Ben heavy truck parts oil seal must pay attention to installation method, otherwise easy to cause oil seal center line and shaft center line not coincide phenomenon, or damage oil seal, the result of oil leakage. Therefore, when the oil seal is installed, it should try to adjust the sealing seat to keep concentric with the bearing and the shaft. This requires that the installation tools and methods be taken into account.
6., keep the oil circuit unblocked, is an important measure to prevent oil leakage. If the oil circuit is too small or blocked, the oil seal oil accumulation of too much pressure, but also easy to cause the oil seal oil leakage, therefore must pay attention to the usual maintenance: (1) maintenance must pay attention to clean, is strictly prohibited in the outdoor maintenance dusty, also prohibit cleaning machines internal parts with cotton yarn, avoid cotton the head clogging oil passage. (2) on time maintenance lubrication system, timely cleaning oil thick and fine filter; when changing oil, should carefully clean the lubrication circuit. (3) when the oil pressure is found to be too high, the cause should be found out and removed in time. In addition, often keep crankcase ventilation open, to prevent Baotou North Ben heavy truck parts crankcase pressure increases, gas channeling, and therefore must be timely maintenance.
For a single cylinder diesel engine, a negative pressure valve can be installed to keep the crankcase from negative pressure or zero pressure and to prevent positive pressure. The negative pressure valve effectively solves the leakage problem, reduces the oil leakage phenomenon, and reduces the oil consumption. As the negative pressure valve window has oil and gas discharge, in the shell inside the reed, the backplane and baffle are oil, dirt easy to stick above, so the negative pressure valve should pay attention to maintenance. The maintenance cycle shall normally depend on the actual situation. The diesel engine maintenance cycle with fixed operation and clean environment may be longer. Under the condition of more dust, the maintenance cycle should be shorter. In the maintenance of negative pressure valve, it should be dismantled, decentralized, clean in the Chai Shan or kerosene rinse, cleaning should not be too much to pull the reed, nor can metal stamping, prevent deformation and warpage of the reed and lose function.

Two 、 static joint surface oil leakage
Reasons for oil leakage on static joint surface and preventive measures are as follows:
1., the quality of the static joint itself is mainly determined by the accuracy of the processing equipment itself and the storage and transportation conditions. If the equipment of high precision, static joint surface flatness, roughness can reach the design requirements of drawing, and in the process of storage to prevent bump, not difficult to achieve the static bonding surface is completely sealed. But because some manufacturers of equipment precision and technology level is still relatively low, storage conditions and management level can not completely guarantee no scratches import pump.
2., maintenance operation, poor technical skills. At present most of the agricultural locomotive is the household business, so in order to self-study, because the repair technology level can not keep up, such problems often occur in the study, especially when dismantling the machine does not pay attention to the method, lack of special tools, parts deformation, or even damage. Due to deformation of parts, causing oil spills. At present, the general disassembly method uses the main bearing seat cover mounting bolt to screw into the main bearing seat cover, and the main bearing cover cover is pushed out in the screw hole of the diagonal disassembly and assembly. It is difficult to achieve the synchronization of the two bolts during the assembly and disassembly, which is the main reason for the deformation of the main bearing housing. The preventive measures are: (1) synchronous operation method should be taken in the demolition process, such as two people at the same time, as far as possible uniform screw bolts; (2) where conditions as far as possible the use of puller, in order to solve the synchronization problem fundamentally.
3. purchase or homemade paper pad quality does not meet the requirements, such as the thickness is not enough, or improper storage, fold deformation, or the assembly does not pay attention to cleaning, stained with dust and impurities, these are the leakage reason.
4., using sealing adhesive, can seal, leak proof, fastening and plugging the role of the gap, to prevent leakage of oil purposes.
5., the oil pressure is too high, but also cause static oil leakage on the joint surface, the reasons and preventive measures are the same as the oil seal.