(1) selection of gear oil
Viscosity grade and selection. Industrial gear oil viscosity classification is in accordance with gb3141-82 "industrial smooth oil viscosity classification" norms, by gear pitch linear speed and gear raw materials and external stress size.
(2) quality grade selection. First, determine the quality level according to the contact stress of the tooth surface, can be selected according to table 1. Generally speaking, the quality grade should be high not low, high grade oil can be used for low occasions, on the contrary is not appropriate.
(3) my company forklift drive axle used by the gear oil. Standard mobile gear oil (MD gx-90) is used in imported forklifts, which meets the requirements of API quality classification gl-4. It is a multi-purpose gear oil with good anticorrosion and rust resistance. It is suitable for curved gears, manual transmission and high-speed passenger and truck.
Domestic forklifts all use 220# medium load gear oil (gl-4), which improves extreme pressure abrasion resistance on the basis of anti-oxygen and anti-rust industrial gear oil, and is suitable for gear with medium load. Such as gear contact stress of 500-1100n2 closed cylindrical gear, helical gear and herringbone gear transmission device.
(2) matters needing attention when using gear oil
(1) pay attention to avoid mixing with water impurities
(2) to choose the appropriate viscosity grade of oil according to the environment temperature, ensure the smooth requirements of high and low temperature operating conditions. If our company is located in the south, winter, summer temperature difference is not as big as the north, and the low temperature moment is not too long, the temperature is not too low. Therefore, our company's forklift has winter and summer use the same brand of gear oil.
(3) in use should often check how much oil. Too much oil will result in high internal pressure and oil leakage, resulting in damage to the semi-shaft oil seal, brake failure, too little oil will make the gear bearing smooth bad, wear and tear of the parts.
(4) to check the performance index of gear oil and pollution, such as overspending to replace. When changing the oil, clean the gear box and then inject new oil.
2, gear oil performance indicators and pollution measurement
(1) determination of water content
Qualitative analysis and quantitative measurement can be used together, usually expressed as a percentage. Replace oil with new oil if the water content exceeds 0.2%.
(2) determination of viscosity
The kinematic viscosity of oil at 40oC and 100oC can be detected. When the viscosity change rate exceeds plus or minus 10% to 15% of the viscosity of the new oil, it is necessary to consider replacing the new oil and to find out the reasons for the viscosity change. If the smooth oil used is MD gx-90, the new oil should be replaced when the kinematic viscosity at 40oC is lower than 153mm2/s or higher than 220mm2/s, and the reason for the viscosity change should be found out. If the smooth oil used is medium load gear oil gl-4, the new oil should be replaced when its 40oC kinematic viscosity is lower than 168.3mm2/s or higher than 286mm2/s, and the reasons for viscosity change should be found out.
(3) determination of solid particles and pollutants
The composition and content of solid particles and pollutants in oil can be determined by spectroscopic analysis and ferrospectroscopic analysis. Replace the oil at the back of the steel particles with more than 10% microns or greater microns in iron spectrum analysis. In the case of spectral analysis, if the Fe content of two successive samples under the additional capacity of smooth oil is close to or exceeds 1000ppm, the smooth oil shall be replaced.
Abnormal oil indicates the existence of faults
Because drive axle gear stains are less polluted and sampling is more difficult, our company has less detection, but because our company has less detection, but because my company and guangzhou machine tool research institute a few years ago in cooperation with the development of "equipment oil condition monitoring" project, we sample sent to guangzhou machine tool research institute for testing. In January 20, 1998 in B727 forklift inspection sample, was in 40 oc the kinematic viscosity of just 67.4 / s, on April 13, 1998, send the sample of the kinematic viscosity of 40 oc as long as 50.2 was/s, and the concentration of Fe, Cu element has a downward trend, and the differential gear oil MD Gx - 90 of its 40 oc kinematic viscosity was normal for 180-200 / s, this may clarify a transmission oil (MD1310, 40 oc kinematic viscosity of 36.8 was/s) into the differential. Detection of the differential gear oil of B718 forklift truck, a similar situation occurred. I tore down the two forklifts and found that the seal ring (transmission frame oil seal) between the transmission and the differential was damaged, which caused the transmission oil to jump into the differential.
The above examples illustrate that oil monitoring can predict machine faults, should cause us enough attention.