The maximum permissible speed for the EP series bearings is shown in Fig. These values Is the limit load achieved when the bearing load is very small, the actual use of these speeds Degree is very difficult to achieve, because the bearing in the work inevitably bear labor As the load, when the bearing load increases when the allowable speed will be reduced. As the bearing speed and bearing operating temperature is inversely proportional to the relationship, so the bearings The maximum speed allowed by the different operating modes is also different.

EP series bearings are limited to the minimum and maximum operating temperature. Minimum Temperature refers to the critical temperature at which the bearing material will become brittle (Figure 10), the highest temperature used Temperature is the bearing wear resistance will not change the critical temperature, short-term operation of the most High temperature is the critical temperature at which the bearing material becomes soft (Figure 9). Such as bearings Often alternating in high temperature and low temperature, the bearing may be shedding phenomenon, So at this time must rely on the auxiliary device to ensure the normal operation of the bearing.

Although the EP series of plastic bearings is designed for dry friction applications, but its general grease and other lubricants are most of the good compatibility; in the bearing Start-up phase by adding lubricating media can improve the bearing's starting performance, thus shortening the bearing run-in period. And the bearing in the presence of a lubricating medium when the carrying capacity will be large Because of the external lubrication intervention in the case of a significant reduction in the friction coefficient of heat generated by the bearing temperature decreases, the bearing capacity will increase. Figure 14 says Out in a variety of lubrication medium under the PV correction factor y2;

As the bearing wear resistance by many factors, it is difficult to accurately Describe the wear or life of the bearing. Through numerous tests that affect the bearing Wear resistance or life of the factors: load, speed, movement, shaft material And roughness, ambient temperature and dust, external lubrication media category and so on. Bearing wear resistance generally increases with the load, speed, temperature and gradually decreased Low, when there is external lubrication medium, the bearing wear resistance will be doubled. Hengxing recommended the use of the shaft roughness Ra0.2 - Ra0.8, the shaft is too rough or Too smooth will lead to increased wear and tear, the shaft is too rough as scraper scratch Bearing the friction surface, the shaft is too smooth in the friction surface and the bearing surface of the glue Leading to increased wear. The EP series bearings for the shaft material are not particularly limited, but are not limited Kind of shaft material on the impact of bearing wear is different, it is recommended to use more Hengxing For the universal surface hard chrome plated shaft material, the hardness of the shaft is also not limited, But Hengxing recommended the use of HRC35 or more shaft material, in order to avoid bearing the initial work For the wear of the stage shaft.

Sliding bearings for outdoor equipment will often be exposed to a variety of harsh environments. Anti-UV properties are an important factor in the resistance of various bearing materials to UV-ray breakage index. EP series of plastic bearing anti-UV performance control chart shown in Figure 16.

EP series of plastic bearings are often used for chemical media contact occasions, at this time bearing anti-chemical corrosion performance is particularly important. As the chemical medium can be Can lead to changes in the composition of the bearing material, this change depends on the type of chemical medium, temperature, exposure time, and bearing load and movement Way, and sometimes the chemical medium as an effective lubricant which will extend the service life of the bearing. See Figure 16 for details.

■ Block hole: EP series plastic bearing with seat hole material None Particularly limited, but the hole at one end must be chamfered 25. To avoid bearing Scratch the outer diameter when pressing, pressing the ladder shaft should be used slowly Press, prohibit direct hit the end, so as not to affect the deformation of the bearing ruler Inch, EP series of internal diameter tolerance are pressed into the H7 standard Hole after the get.

■ The axis: EP series of plastic bearings with the axis of the material without special Do not limit, but Hengxing recommend the use of chrome-plated hard axis. To make the axis In the assembly process is more simple and does not damage the bearing friction surface, shaft The end face must be chamfered smooth transition. Another axis surface roughness The friction coefficient of the bearing has a greater impact, the shaft is too smooth friction surface Will produce crawling phenomenon or produce scream, the axis surface is too rough will Speed up the bearing wear. Hengxing recommended the use of shaft surface roughness Ra0.2-0.8. Bearing friction coefficient and surface roughness of the relationship shown in Figure Table 19.

Chart 17: Press-fit diagram

Chart 19: Relationship between friction coefficient u and shaft surface roughness Ra

EP series bearings with the tolerance in accordance with IS0 3547-1 standard design and manufacturing see Figure 18. Although the EP series of products designed for self-lubricating products, but in the equipment Timing on the friction surface coated with an appropriate amount of external lubricant (such as grease) will shorten the bearing of the run-in period and thus extend the service life of the bearing.

■ Adhesives : EP series plastic bearings generally do not need to use adhesive, High temperature adhesive, Hengxing suggested that the necessary testing of this situation.