How to select grease?

Lubrication of the bearing work and life have important influence, this to you a brief introduction to select principle of grease. Grease made out of base oil, thickener and additive, different types and with different number of grease properties vary widely, allowing the rotation of the limit, when the choice is important to note. The performance of the grease is mainly composed of base oil, low viscosity of base oil is suitable for low temperature, high speed, high viscosity is suitable for high temperature, high load. Thickener and relationship with lubrication performance, thickening agent, water resistance to the water resistance of the grease. In principle, the son of different grease cannot be mixed, and even the same thickening agent of grease, will also bring bad influence each other on the basis of different additives. Choose bearing grease should consider the following factors: 1, the working temperature, rotating speed and load bearing lubricant viscosity had a great influence on the oil film thickness, the lower the viscosity of lubricating oil, the oil film bearing capacity, oil film is easy to broken. In order to form need oil film thickness, lubricant must have fixed viscosity under the working temperature. And lubricant viscosity is by the rise of temperature, therefore, the working temperature is high, should choose high lubricant viscosity, low working temperature should be chosen when low viscosity of lubricant. For grease lubrication, grease drop point said fat high and low temperature performance, high working temperature should be chosen when high dropping point of lubricating grease. , using temperature should be lower than drop point 10 ~ 20 ℃, the use of synthetic grease temperature should be lower than 20 ~ 30 ℃ drop point. Working at high temperature, should choose good viscosity-temperature and high temperature oxidation resistance of good fat; Work at low temperature, should choose the low temperature liquid grease. Within the bearing lubricant can produce viscous friction in the bearing operation. Under the same speed, the greater the viscosity, the greater the friction, the higher the temperature rise, it will make work lubricant viscosity drops. Speed is high, therefore, should choose low viscosity lubricating oil or grease base oil viscosity is small. Bearing load of the influence of oil film thickness, the greater the load, the smaller the oil film thickness, so the light load time choose the lubricant with low viscosity; Heavy load of high viscosity, and with ep additives. 2, environmental conditions, working in a damp environment bearing should choose anti-corrosion performance of the grease. Mechanical working in humid environment, and going to stay a long time, will stay after the bearing surface because of cooling and formation of condensation water, to prevent rust, should choose not bibulous calcium base grease. When bearing the surrounding dust, and sealed with curved road, hope also plays a role of sealing grease, should choose smaller penetration of grease. When bearing medium has a strong chemical action, should choose grease with anticorrosion additive. 3, use of grease lubrication performance of bearing operation, when the friction don't hours, or demand under the low temperature starting friction torque hours, should be chosen by the synthetic base oil of low viscosity and similar penetration bigger grease. For low noise motor bearing, should choose the filtered stearic or high viscosity base oil and grease to minimize bearing noise. 4, the service life of the life of the grease grease depends not only on the performance of the grease itself, also with external conditions such as temperature, speed, vibration, load, environment and so on. Used in time in the sealed bearing lubrication, grease should be greater than the life of a bearing fatigue life. In no bearing lubrication grease filling device applications, the life of the grease should be used in the whole machinery of overhaul. 5, grease filling grease filling amount for bearing box design, space volume, different rotating speed and different grease. Filling quantity indicators for bearing and bearing housing space volume and 30 ~ 60%. Rotation speed is high, to reduce the temperature rise and decrease fill. Too much grease filling, high temperature, easy to soften grease leakage or performance degradation caused by oxidation metamorphism, such as grease. 6, the requirement of intermiscibility if two incompatible but a mixture of grease, will change the performance of the grease, so in principle, different number of grease can not mix. In the hard to avoid a mixture of different kinds of grease, at least the same categories of thickening agent, similar grease base oil. When added grease, should be added with grease. Tags: bearing grease