What happens when a sliding bearing works is sliding friction; the magnitude of the sliding friction force mainly depends on the manufacturing accuracy; and the magnitude of the sliding bearing friction force mainly depends on the material of the sliding surface of the bearing. General working surfaces of sliding bearings have a self-lubricating function; sliding bearings are divided into non-metal sliding bearings and metal sliding bearings according to their materials.
Non-metallic sliding bearings are mainly plastic bearings. Plastic bearings are generally made of engineering plastics with better performance; more professional manufacturers generally have engineering plastics self-lubricating modification technology, through fibers, special lubricants, glass beads Wait for the self-lubricating enhancement modification of engineering plastics to achieve a certain performance, and then use modified plastics to process self-lubricating plastic bearings through injection molding.
Three-layer composite bearings are most commonly used in metal sliding bearings at the beginning of the 21st century. Such bearings generally use carbon steel plates as the substrate. A sintering technique is used to sinter a layer of spherical copper powder on the steel plate, and then on the copper powder layer. The upper layer is sintered with a PTFE lubricant of about 0.03mm; the middle layer of spherical copper powder is mainly used to enhance the bonding strength between the steel plate and PTFE. Of course, it also plays a certain bearing and lubricating function during work.
The contact angle should not be too large or too small. If the contact angle is too small, it will increase the pressure of the sliding bearing. In severe cases, it will cause large deformation of the sliding bearing, accelerate the wear and shorten the service life. If the contact angle is too large, it will affect the formation of the oil film and fail to obtain good liquid lubrication.
Experimental research shows that the limit of the contact angle of the plain bearing is 120 °. When the sliding bearing wears to this contact angle, the liquid lubrication is destroyed. Therefore, under the premise of not affecting the pressure condition of the sliding bearing, the smaller the contact angle, the better. From the theoretical analysis of the frictional distance, when the contact angle is 60 °, the friction torque is the smallest. Therefore, it is recommended that for sliding bearings with a rotation speed higher than 500r / min, the contact angle should be 60 ° and the sliding bearings with a rotation speed lower than 500r / min The contact angle can be 90 ° or 60 °.
