A new kind of friction-reducing and repairing additive containing nano-scale copper and rare earth compounds were prepared by means of synthesis and compounding methods. The performance of the said additive was invest...A new kind of friction-reducing and repairing additive containing nano-scale copper and rare earth compounds were prepared by means of synthesis and compounding methods. The performance of the said additive was investigated by engine bench test, and was compared to the performance of similar domestic and imported additives. The deterioration of lube oils containing additives over different time intervals was studied by means of plasma spectrometry and mass spectrometry, and the effect of additive package on engine power was also studied. Test results have revealed that the synthetic additive package can provide good anti-wear performance to the tribo-pairs. In particular, after 300 hour application of the said additive package the connection rod shaft and copper sleeve showed 'zero wear' to achieve the in situ dynamic repairing of tribo-pairs. Application of the said synthetic additive can effectively improve the engine power performance and extend the engine service life.展开更多
Because the applications of single-anchor leg mooring yoke systems(SYSs)are rarely studied in the offshore industry,the design of such systems features some uncertainties.This paper investigated the effect of eccentri...Because the applications of single-anchor leg mooring yoke systems(SYSs)are rarely studied in the offshore industry,the design of such systems features some uncertainties.This paper investigated the effect of eccentricity on the wear of the topside axial bearing of a SYS.The eccentricity of the topside was verified by on-site inspection,and the axial bearing wear was found to be far more serious than the original design.The contact status between the axial bearing and flange surface was studied on the basis of the actual topside load by using nonlinear finite element analysis.Wear tests of the topside bearing under uniform and eccentric loads were also performed to study the effect of eccentric loads on the wear rate.The key parameters obtained from numerical simulations and experimentation were used to calculate the wear depth via a simplified linear wear model based on the product of the pressure and sliding distance.Results showed that eccentric loads are the main factor responsible for the excessive wear of topside axial bearings.展开更多
The use of asbestos material is being avoided to manufacture the brake pads as it is harmful and toxic in nature. Further it leads to various health issues like asbestosis, mesothelioma and lung cancers. These brake p...The use of asbestos material is being avoided to manufacture the brake pads as it is harmful and toxic in nature. Further it leads to various health issues like asbestosis, mesothelioma and lung cancers. These brake pads can be replaced by natural fibers like Palm kernel (0-50%), Nile roses (0-15%) and Wheat (0-10%) with additives like aluminum oxide (5%-20%) and graphite powder (10%-35%). Phenolic resin of 35% is utilized as a binder. Particulated Nile roses are used to increase the friction coefficient and wheat powder is used to reduce the wear rate. Aluminum oxide and graphite are abrasive in nature. This helps to make brake pads with high friction co-efficient and less wear rate with low noise pollution. The wear of the proposed composites have been investigated at different speeds. Various tests like wear on pin-ondisc apparatus, hardness on the Rockwell hardness apparatus and oil absorption test have been conducted. Phenolic resin produces good bonding nature to fiber. Thus, Fibers found to have performed palatably among all commercial brake pads. The objective of the research indicates that Palm kernal shell could be a conceivable alternative for asbestos in friction coating materials.展开更多
文摘A new kind of friction-reducing and repairing additive containing nano-scale copper and rare earth compounds were prepared by means of synthesis and compounding methods. The performance of the said additive was investigated by engine bench test, and was compared to the performance of similar domestic and imported additives. The deterioration of lube oils containing additives over different time intervals was studied by means of plasma spectrometry and mass spectrometry, and the effect of additive package on engine power was also studied. Test results have revealed that the synthetic additive package can provide good anti-wear performance to the tribo-pairs. In particular, after 300 hour application of the said additive package the connection rod shaft and copper sleeve showed 'zero wear' to achieve the in situ dynamic repairing of tribo-pairs. Application of the said synthetic additive can effectively improve the engine power performance and extend the engine service life.
基金supported by the Project of China Offshore Oil Engineering Company(Tianjin)CCL2014CFD。
文摘Because the applications of single-anchor leg mooring yoke systems(SYSs)are rarely studied in the offshore industry,the design of such systems features some uncertainties.This paper investigated the effect of eccentricity on the wear of the topside axial bearing of a SYS.The eccentricity of the topside was verified by on-site inspection,and the axial bearing wear was found to be far more serious than the original design.The contact status between the axial bearing and flange surface was studied on the basis of the actual topside load by using nonlinear finite element analysis.Wear tests of the topside bearing under uniform and eccentric loads were also performed to study the effect of eccentric loads on the wear rate.The key parameters obtained from numerical simulations and experimentation were used to calculate the wear depth via a simplified linear wear model based on the product of the pressure and sliding distance.Results showed that eccentric loads are the main factor responsible for the excessive wear of topside axial bearings.
文摘The use of asbestos material is being avoided to manufacture the brake pads as it is harmful and toxic in nature. Further it leads to various health issues like asbestosis, mesothelioma and lung cancers. These brake pads can be replaced by natural fibers like Palm kernel (0-50%), Nile roses (0-15%) and Wheat (0-10%) with additives like aluminum oxide (5%-20%) and graphite powder (10%-35%). Phenolic resin of 35% is utilized as a binder. Particulated Nile roses are used to increase the friction coefficient and wheat powder is used to reduce the wear rate. Aluminum oxide and graphite are abrasive in nature. This helps to make brake pads with high friction co-efficient and less wear rate with low noise pollution. The wear of the proposed composites have been investigated at different speeds. Various tests like wear on pin-ondisc apparatus, hardness on the Rockwell hardness apparatus and oil absorption test have been conducted. Phenolic resin produces good bonding nature to fiber. Thus, Fibers found to have performed palatably among all commercial brake pads. The objective of the research indicates that Palm kernal shell could be a conceivable alternative for asbestos in friction coating materials.
