Views: 41 Author: Site Editor Publish Time: 2024-06-02 Origin: Site
The cages of Rolling bearings have two structural designs: with cage and without cage. High-load, low-speed cylindrical roller bearings, deep groove ball bearings and thrust tapered roller bearings, CARB toroidal roller bearings generally adopt a cage-free design. Special bearings such as high-temperature bearings, high-speed turbojet bearings and other ball bearings also adopt a cage-free design.
Most rolling bearings are equipped with cages. The main functions of the cage are:
1. The cage separates the rolling elements at equal distances and is evenly distributed on the circumference of the raceway to prevent collision and friction between the rolling elements
2. Guide and drive the rolling elements to roll on the correct raceway;
3. The cage space can store grease;
4. In a separable bearing, the rolling element and a ring are combined together to prevent the rolling element from falling off.
Nylon cages, scientific name polyamide PA66
Polyamide 66 (PA66) is the most common material for injection molded nylon cages. This material has a good combination of strength and elasticity, whether or not it contains glass fibers. The mechanical properties of polymer materials, such as strength and elasticity, are temperature-dependent and are susceptible to aging. The factors that have the greatest influence on the aging process are temperature, time and the medium (lubricant) to which the polymer is exposed. Cage life decreases with increasing temperature and the aggressiveness of the lubricant.
The suitability of a polyamide cage for a specific application therefore depends on the operating conditions and life requirements. Lubricants are divided into "aggressive" and "mild", which is reflected in the "permissible operating temperature" of cages made of glass-fiber reinforced PA66 with various lubricants
Polyamides lose their elasticity at low temperatures. Therefore, cages made of glass-fiber reinforced PA66 should not be used in applications with continuous operating temperatures below –40 °C.
Polyamide 46
Glass-reinforced polyamide 46 (PA46) is the standard cage material for some small and medium-sized CARB toroidal roller bearings. The permissible operating temperature is 15 °C (25 °F) higher than glass-reinforced PA66.
Polyetheretherketone
Glass-reinforced polyetheretherketone (PEEK) is better suited than PA66 and PA46 for demanding conditions such as high speeds, chemical resistance or high temperatures. The superior properties of PEEK provide an excellent combination of strength and flexibility, a high operating temperature range, and high chemical and wear resistance. Due to these outstanding properties, PEEK cages are often used in hybrid and/or super-precision ball and cylindrical roller bearings. At temperatures up to 200 °C (390 °F), the material shows no signs of aging due to temperature or oil additives. However, the maximum temperature limit for high-speed use is 150 °C (300 °F) as this is the softening temperature of the polymer.
Nylon bearing cages have low vibration, low noise, low heat generation, high load-bearing capacity, and can improve the bearing's limit speed and life. They can usually work stably for a long time in the temperature range of -40℃+80℃, and are compatible with bearing lubricants. Nylon bearing cages are suitable for motors, machine tools, gear transmission shafts, pumps, compressors and other fields.
Now nylon cages are used more and more, so what are its advantages? The nylon cage of the bearing is a new generation of products that currently replace copper cages and iron cages. Compared with metal cages, it has many advantages:
1. it is light in weight and improves the flexibility of the bearing. If it is used in electrical appliances or power-consuming products, it has a great effect on energy saving.
2. it is light in weight, and the centrifugal force generated by the bearing itself during rotation is relatively small, which is more suitable for high-speed working conditions.
3. it has low noise and is the first choice for manufacturing silent bearings, especially for electrical appliances with high noise requirements. Nylon cages are the first choice.
4. it has low friction and can effectively extend the service life of the bearing. The friction between the nylon cage and the rolling element is lower than the friction between the metal cage and the steel ball, which greatly extends the service life of the bearing.
5. it is easy to manufacture, which greatly improves production efficiency and reduces production costs.
Although the nylon cage has so many advantages, it also has many disadvantages during the use of the bearing, mainly including: the compressive strength of the nylon cage is not as strong as the metal steel cage, and the load capacity is not high.
In short, metal cages and nylon cages of bearings have their own advantages and disadvantages. When choosing, you should choose according to the use requirements. For example, if you require low-noise electrical appliances, you should choose nylon cage bearings. For equipment with high temperature, large load, and large vibration, you should give priority to stamping steel cages or machined copper bearings. If nylon cage bearings need to be used in special working conditions such as high temperature and corrosion, please contact us.