1 import generic low-noise motor bearing grease
Bearing the import industry, the largest such application of grease, with the total fat content of 70%. Since this type of grease used in fiber is soft, easy filter to do the lithium soap thickener, use mineral oil as base oil, it is easy to meet the medium and low value of imported bearings reduce vibration requirements. Another advantage is a good pumping, plus fat, whether mechanical or hand-painted resin, are simple and easy. Moreover, the grease of the low price, can greatly reduce the cost of imported bearings. However, due to the use of mineral base oil, so that such grease rust and corrosion protection in a number of other physical and chemical indicators greatly reduced. Such as the bearing life can only import up to 200 hours, starting and running torque test at -20 ℃ have difficulties. Type of grease temperature is generally -20 ~ 120 ℃, when used in high temperature above 150 ℃, the base oil will be rapid evaporation, loss and serious phenomenon, greatly reducing the service life of bearings.
(2) high temperature bearing grease imports
Currently, the use of increasingly sophisticated equipment bearing imported fine, and promoting imports bearing grease used must have the following properties:
(1) and imported bearings with the same operational life, try to extend the maintenance cycle, reduce downtime, improve labor productivity.
(2) dn> 5 × 105 to ensure that the motor speed under low temperature, do not dump oil, thereby reducing power consumption, protect the motor.
(3) the impurity content under control in a certain standard, the maximum noise reduction equipment for environmental pollution.
(4) working conditions in the ultra-low temperature starting and operation to ensure that imported bearings of flexibility, to ensure minimum power output.
Foreign companies to use high purity grease synthetic oil and special chemical additives, in the high cleanliness of the environment and equipment developed and produced a low-temperature high-speed bearings with grease. The disadvantage of this type of grease is used in more than 150 ℃, with a sharp temperature drop of its life, anti-impact ability to load and weak, should be avoided in large-scale use of imported bearings, lubrication and to prevent the border produce sintering.
3 low-noise high-temperature long-life grease bearings
In the high-temperature grease used in high speed environments should have the following characteristics:
(1) at high temperatures without loss, that is, the temperature at about 180 ℃ to maintain a certain consistency, not softening.
(2) oil leak less. When the grease in the bearings to withstand repeated high-frequency cut-and-large centrifugal force, the lubricant can not promptly thrown back into the raceway.
(3) have a certain type of high-temperature grease life at high temperatures with good oxidation resistance, thereby prolonging the import of the life of bearings and related equipment.
(4) has a certain quiet effect, due to high temperature grease hardness of the fiber is generally larger, so the imported bearing noise test is far less than in the quiet performance of lithium-based grease.
High-temperature long-life grease is generally divided into two types of lithium complex grease, the high-temperature performance is better, but because of its low molecular weight thickening agent in crystalline acid added to increase the hardness of the larger fibers in the Bearing vibration performance is poor in performance. However, by controlling the degree of polymerization, molecular weight distribution of a class to get the resultant, resultant of such special methods of oil dispersed in the base, then made another noise performance and excellent high temperature performance of the same grease.
This grease is greater than the average drop point 250 ℃, with temperature up to about 200 ℃, the thickener does not contain **l ions in the crystal, fiber stiffness smaller, very good noise performance. Also, because of its basic chemical composition with the thermal coupling between the effect of reducing the high-temperature grease. This high-speed low-noise high-temperature grease does not contain anything that can cause catalytic oxidation of the **l ion and, rich in nitrogen and oxygen atoms of the thickening agent is an anti-oxides, so the bearings are better life and sound quality .