The actual working temperature of the idler shall be lower than dropping point 10-20 degrees centigrade. The use temperature of synthetic grease shall be below dropping point 20-30 centigrade.This is due to the selection of grease in accordance with the operating temperature of the sealed bearings, the main indicators should be drop point, oxidation stability and low temperature performance, drop point can generally be used to evaluate high temperature performance.So choosing good grease is very important for good quality conveyor rollers.
　Roller bearing load select grease, grease for heavy load should be selected penetration small. When working under high pressure, besides high penetration, it also has higher oil film strength and extreme pressure performance. When the grease is selected according to the environmental conditions, the calcium based grease is not soluble in water and is suitable for drying and less moisture.So good quality conveyor rollers is very important.
　The service life of the roller depends mainly on the performance of the bearing and sealing. If the bearing and sealing performance of the roller are good, the service life of the roller will be greatly prolonged. The test results show that the friction resistance of Yuezhantuo roller rotary bearing 1/4~1/8. Therefore, choosing good grease is very important for reducing the resistance of roller bearing.Good quality conveyor rollers is very important for a long use time.
　Improper selection of grease will cause damage to the bearing, which will lead to damage to the idler. MT821-2006 coal industry standard clearly requires the selection of 3# grease, the manufacturer must comply with. Otherwise, the roller will be damaged after a few hours running. What is emphasized here is that, for the idler bearings under -25 operating conditions, a special type of low temperature resistant aviation grease must be selected.
This is a rising trend in coal prices because of the arrival of the dog days and more hot.Last week, the country ushered in a large range of high temperatures, electricity demand increased, the country’s electricity generation is a new high, which also led to the continued supply of coal tight. And into mid late 7, high temperatures will continue, coal demand will increase.In the supply side is still tight circumstances, demand side impetus is expected to boost the market once again higher.
Over the past few days, the power supply level of the whole network has been rising continuously due to the influence of a large range of persistent high temperature weather. From July 11th to July 13th, the country’s electricity generating capacity reached a record high, up 7% from its peak last summer. Beijing, Tianjin, Hebei and other 12 provincial power grid load reached a record high.As coal demand has been strong, coal prices have risen steadily since mid June. With the continuous hot weather, coal prices are also expected to rise. Although the NDRC has stressed the need to increase the supply of coal, but with the arrival of the peak summer season, the demand for coal has increased, coal supply is still tight.