Deep Groove Ball Bearings |
Structure of deep groove ball bearing basically include inner ring, outer ring, roller elements and cages. Seal rigns and dust shields are designed to prevent foreign matters like dust or oils from entering. The main purpose of lubricant used is to achieve the reduction of friction and damage of roller elements. |
Rivet type cage It is a kind of cage made by strip steels in high precision, turned into spherical pockets through profiling and fixed with rivets, usually applied to small and medium deep groove ball bearings. |
Crank jaw type cage It is a kind of cage made by strip steels in high precision, turned into spherical pockets through profiling and caulked by crank jaw and two pairs of retainers, usually applied to miniature deep groove ball bearings. |
Cage with synthetic resin material Synthetic resin cage is made by combination of several materials, including nylon PA66 with glass fiber. It has self-lubricating and low noise features, usually used for bearings with extremely low noise. |
Steel Code |
Chemical composition% | ||||||||
Gcr15
SAE52100 DIN 100 Cr6 JIS SUJ2 |
C | Si | Mn | P | S | Cr | Mo | Cu | Ni |
0.95-1.05 | 0.15-0.35 | 0.25-0.45 | <0.025 | <0.025 | 1.40-1.65 | - | <0.25 | <0.30 |
Steel code |
Chemical Composition% | ||||||
JISG 3141
SPCC |
C | Si | Mn | P | S | Ni | Cr |
<0.12 | - | <0.5 | <0.04 | <0.045 | - | - |
Type |
ASTM D1418 Name | Temperature Range |
Hardness
(Shore A) |
Features | Restriction |
Nitrile butaduene rubber | NBR | -40ºC~120ºC | 40-90 |
Low compression
High ductility High corrosion resistance superior oil resistance |
Unsuitable for high temperature conditions;
No exposure to the sun and corrosion of chemicals |
Silicon rubber |
MQ/PMQ
VMQ/PVMP |
-70ºC~200ºC | 25-80 |
High temperature resistance
Desiccation resistance Sunshine resistance aging resistance to ozone |
Poor surface abrasion performance and crack resistance, higher wear resistance |
Hydrogenated
(nitrile-butadiene rubber) |
HNBR/NEM | -35ºC~65ºC | 50-90 |
Heat resistance
High ductility Chemical resistance |
Unsuitable for high temperature conditions and shall avoid exposure to the sun and corrosion of chemicals |
Fluororubber | FKM/FPM | -28ºC~200ºC | 50-95 |
High temperature resistance
Significant chemical resistance corrosion resistance to petroleum products |
It is not suitable for working conditions of low temperature. |
ACM rubber | ACM Rubber | -18ºC~175ºC | 40-90 |
Stronger resistance to hot oil
Sunlight and ozone Higher crack resistance |
poor waterproof performance;
unsuitable for working condition of ultra-low temperature |
Warning:flurorubber is safe and harmless under normal working condition of below 200ºC, but it will give off smoke if the temperature exceeds the ultimate temperature of 300ºC that is equivalent to flame for cutting steel tubes. Inhalation of the smoke is harmful to human bodies including eyes. In addition, the smoke should be avoided to contact skin. |
Grease lubrication |
Lipid lubricants are much easier to use than oil lubricants. Due to its ciscosity,grease is more durable and only needs simple sealing equipment to contain. Grease is hard to be changed, beacause the usual approach of it is to press grease into device to make fresh grease squeeze used grease out. General speaking, grease with low viscosity primary oil is more suitable for high speed operations at low temperature, while grease with high viscosity primary oil is suitable for heavy load. |
Oil lubrication | Oil lubrication is more suitbale for applications under conditions of high speed and high temperature, effectively taking the heat generated in operation of bearings away. Viscosity of oil determines the effects of oil lubrication. Low viscosity will lead to inadequate formation of oil film, while high viscosity will increase viscous drag and temperature. In general, the higher rotational speed is the lower viscosity of lubricant oil will be; the larger load is, the higher viscosity of lubricant oil will be. |
Primary oil | In grease, primary oil accounts for 75-96%. In mass fraction, the performance of grease mainly relies on the nature of primary oil. Particularly when it is with cold flow property and at high temperature, its service life is bound up with primary oil. Grease with low viscosity primary oil is usually applicable to low temperature and low load, while lubrication grease with high viscosity primary oil is applied to high temperature and high load. Primary oil used in grease includes mineral oil and synthetic oil. The commonly used synthetic primary oils contain lipid oil, sythetic hydrocarbon oil, perfluoropolyether, silicon oil and PPO, etc. |
Thickener | Thickener generally accounts for 4~20% in mass fraction. Its functions are to suspend primaty oil, reduce the flow of primaty oil, and increase adhesion of oil to friction surface. Thickener has two categories: metallic soap base and non-metallic soap base. Critical operating temperature, mechanical stability, water resistance and other properties of grease are determined by thickener, for example, sodium soap base can react with water to form a kind of latex, which can not be applied to running bearing in the atomsphere of high temperature. |
Additive | In grease, primary oil accounts for 0.5~10%. In mass fraction, which is used for the improvement of operating performance and life of grease. Accordign to the classification by function, it can be divided into thickener(strong adhesion), antioxidant, extreme-pressure additive, corrosion inhibitor,etc. |