Research And Analysis Of Single Row Four-point Contact Slewing Bearing In High Temperature Condition

Slewing bearing is also known as wheel bearings,rotating support or swing support. It is a new gradually rising mechanical part in nearly four decades in the world. It is one of mechanical basic components used between the two parts which need relative rotation and at the same time need to bear axial force, radial force and overturning moment. Its basic function is to carry power transmission and drive to achieve relative rotation between the two parts of machinery and equipments. The domestic market of rotary bearing is mainly used in the construction machinery industry. The largest amount is single row four point contact ball slewing bearing, accounting for more than 95% of the total market share, and the raceway diameter lies between 500～1500 mm accounts the most, which have a small processing difficulty, a huge market and low equipment cost. As the continuous development of construction machinery, wind power industry, heavy vehicles, metallurgical machinery, oil industry, military and other fields, swing bearing is widely used and need to have more performance, one of which is high temperature properties, which means that the bearing raceway, cage, seals and lubricants can withstand a high temperature, and can keep its performance quality.Due to bearing alternating pressure and temperature changes, the high temperature slewing bearing product for a particular occasion will produce fatigue, creep and interaction mutually. To ensure the product’s mechanical properties and life, it should need higher requirements on choosing materials, machinery processing, heat treatment process, the corresponding tooling equipment and testing instruments. Aginsr QWA1312.45, the external gear type single row four-point slewing bearing, based on the analysis of carrying case at room temperature firstly, This paper focuses on slewing ring bearing properties at high temperatures. The thermal stress analysis about rotary bearing respectively at high temperature environment of 180℃ and 300℃ is made at first, and find some questions when the rotary bearing work at a high temperature of 300℃.Then analyzed several different materials slewing bearing and find the same problems, so This paper proposes some structural improvement methods for slewing bearings working under high temperature. Then this paper finds the rotary support structure parameters of best carrying capability under high temperature environment analyzed by orthogonal test method to reduce the slewing bearing raceway contact stress. Finally this paper carrys creep analysis on slewing bearing working at long-term high temperature environment and explores the possibility of slewing bearing working long hours at a high temperature occur creep damage, and get the safe time during which working in high temperature creep damage does not occur.Through the above analysis and research this paper carrys on theoretical research and exploration for the development of the new slewing ring suitable for high temperature conditions (frequency furnace, hot metal ladle furnace subcontracting, etc.).