Study on Lubrication Mode of Triple Gear Oil Pump Bearing
At present, there are several lubrication methods for three-gear oil pumps: use high-pressure leakage oil for lubrication; high-pressure lubrication that supplies continuous or pulsed oil to the bearing; high-pressure lubrication that uses the reduction of the trapped oil volume to supply pulsed oil to the bearing
Under normal circumstances, the bearing lubrication mode selection is correct or not determines the triple gear oil pump bearing conditions and life, so this is also a very important part of the gear pump design. At present, the lubrication methods of three-gear oil pumps are as follows: use high-pressure leakage oil for lubrication; high-pressure lubrication that supplies continuous or pulsed oil to the bearing; high-pressure lubrication that uses the reduction of the trapped oil volume to supply pulse oil to the bearing; direct introduction of high-pressure oil The bearing in the bearing hole realizes high-pressure lubrication; the vacuum oil suction and low-pressure self-priming lubrication formed when the trapped oil volume is expanded; spiral drain or suction type low pressure lubrication and use auxiliary pump oil supply for low pressure lubrication.
The former lubrication method is generally used in rolling bearings and other lubrication methods that require low oil cleanliness and low working oil temperature. The second to fourth lubrication methods use high-pressure oil for lubrication, which loses part of the high-pressure oil and reduces The volumetric efficiency of the gear oil pump, the latter two lubrication methods, one of which reduces the bearing surface carrying capacity, and the other is not adopted due to complex structure and high cost. Using the vacuum oil suction low-pressure self-priming lubrication formed when the trapped oil volume is expanded, due to its simple structure, low manufacturing cost and high comprehensive performance, it is widely used in the lubrication of the rolling and sliding bearings of the triple gear oil pump.
Using the vacuum oil suction low pressure self-priming lubrication formed when the trapped oil volume is expanded, a larger oil passage is connected to the low pressure area outside the bearing, so that the pressure outside the bearing is the same as the low pressure area. Due to the use of DU bearings, it is necessary to design a lubricating oil groove axially on the non-bearing surface of the inner hole of the bearing, and form a lubricating oil groove on the inner chamfer of the inner hole of the side plate, so as to achieve the purpose of smooth passage of lubricating oil and stable oil storage.
The low-pressure area on the inner side of the side plate is designed with a rectangular slender groove and is connected with the lubricating oil groove of the two bearing holes. When the gear rotates, due to the expansion of the trapped oil volume, a vacuum is formed at the rectangular groove first, thus an instantaneous pressure difference is generated at both ends of the bearing, so that a small part of the oil in the low pressure area enters the axial oil groove of the bearing hole along the designed oil path. At this time, the oil can lubricate and cool the bearing well, and then the oil passes through the oil collecting groove and the rectangular long groove in turn, and fills the enlarged interdental volume, in this way, a complete lubrication system can be formed.
This lubrication method used by the triple gear oil pump has many advantages: because the oil temperature in the low pressure area is relatively low, the more conducive to the formation of the pressure-bearing oil film of the sliding bearing, and the low-temperature oil can take away most of the bearing heat, which is excellent The bearing lubrication and cooling effect. It can be seen that compared with other lubrication methods, this lubrication method not only has a simple structure and low loss, but also increases the volumetric efficiency of the three-gear oil pump.