Turntable Bearing tooth making process and Forging Material Selection

The Material Selection of turntable slewing bearing forging should be based on the use occasion, importance, process conditions and equipment capacity of the manufacturer as well as the cost level.

Firstly, the turntable slewing bearing requires the mechanical, physical and chemical properties of steel to meet the requirements of use, so as to ensure the service life of the product. The working condition of the turntable slewing bearing  is generally worse, and it has to bear high axial load, overturning moment and radial load.

Secondly, turntable slewing bearing requires steel with good processing and heat treatment process performance. In the process of processing, billet rolling, casting, forging, cutting and so on should be easy to carry out in many heat treatments. Its tendency of overheating, deformation, cracking and decarbonization should be small, and it should have better hardenability, proper hardenability and high tempering stability.

So the turntable slewing bearing rings, are generally made of 50Mn steel. According to the hardness requirements of users, normalized 50Mn or tempered 50Mn steel can be selected. Generally speaking, tempered 50Mn steel has higher hardness, better wear resistance and a slightly higher price than normalized 50Mn steel.If the user needs higher hardness and wear resistance, 42CrMo steel can be selected with higher cost.

The key of Turntable Bearing tooth making process is tooth surface machining. At present, the main methods of tooth making are cutter cutting and grinding wheel grinding.The former because of high machining efficiency, high machining precision, it is the current optical release of tooth surface processing method.

There are two main reasons for the early failure of turntable slewing bearings, one is broken teeth; the other is raceway damage. Among them, broken teeth are the main reason, accounting for more than 90%, and the vast majority occurred within six months after shipped. This not only seriously plagued the product quality reputation of the turntable slewing bearing manufacturer, but also adversely affected the market of the main engine factory. Therefore, solving this problem seriously is the common goal and responsibility of the turntable slewing bearing manufacturer and the main engine factory, and further cooperation between the two parties.

In order to improve the service life the turntable slewing bearing, we have focused on the tooth making process.Now we have 1 pc CNC gear cutting machine,1 pc High speed gear milling machine, 8pcs Gear hobbing machine,7pcs Gear shaping machine. In 2022,we will have 167pcs production equipment in new plant with annual production capacity of turntable slewing bearing 70000pcs/year.