It is necessary to make the journal and sliding bearings evenly and in fine contact, but also have a certain gap.
The contact angle refers to the center angle of the contact between the journal and the plain bearing. Contact angle can not be too big nor too small. The contact angle is too small will increase the sliding bearing pressure, serious will make the sliding bearing a greater deformation, accelerated wear and shorten the service life; contact angle is too large, will affect the formation of oil film, not a good liquid lubrication.
The experimental study shows that the limit of the contact angle of the sliding bearing is 120 °. When the sliding bearing wears into this contact angle, the liquid lubrication is destroyed. So no longer affect the sliding bearing under pressure conditions, the contact angle is as small as possible. From the theoretical analysis of the friction force, when the contact angle is 60 °, the friction torque is the smallest, so it is suggested that the sliding bearing with speed higher than 500r / min has a contact angle of 60 ° and a speed of less than 500r / min, The contact angle can be 90 ° or 60 °.
Contact point
The actual contact of the journal with the surface of the sliding bearing can be expressed by the actual number of contacts per unit area. The more contact points, the more detailed, the more uniform, said the sliding bearing scraping the better, on the contrary, it means that the sliding bearing scraping research is not good. Generally speaking, the more fine the contact point, the greater the difficulty of scraping research. Production should be based on the performance of sliding bearings and working conditions to determine the contact point.
The so-called scraper, that is, after the tires of the tires and the assembly of the shaft Shouban developed (the axis to be coated with toner), with a triangular scraper scraped on the tile attached to the pink, with the research with scraping until the tile Attached to the area of ​​more than 85% of the whole tile surface, complete scratch. The presence of the inserts on the tiles is the micro-tank of the tiles that store the lubricating oil.