Cross is the mainly component of Universal joint. It can transmit large torque at low friction. Universal joint cross with journal pegs and bearing cases as outer ring are hot forged and machined. They are later carburized in furnace so that increased ruggedness and wear resisitance are obtained. Parts are finally ground to designed size under severe tolerance. Oil seal as well as dust cover are also in use to protect internal journal area from intrusion of foreign material. Variety of grades and materials are selected to repond to extreme conditions such as very hot / very cold temperatures.
Like other closed die forgings, universal joint cross starts from the developing of forging mold/dies. The mold/dies is machined from tool steel, and will be heat treated so that it will extend the serving life of dies under hot tempering and can withstand high impact. Depond on the sizes of universal joint cross, mold of larger universal joint cross is always more expensive.
To obtain good precision, and reduce machining cost, such universal Joint crosses are hot precision forged in closed dies. According to the types of universal joint crosses, forging presses selected mostly range from 160 tons to 400 tons. Of course, for larger type, heavier forging press will be applied.
CFS Steel Forging can supply custom universal joint cross forgings in any desired material specification. Currently, more widely used material grade is 40Cr.
Main process of forging universal joint cross is: Choosing round bars in equal size, and cutting them by sawing machine into required length, then heat to a certain temperature. Next is to deliver the heated bar by conveyor belt to the forging press, and place it under forging dies and press for several seconds. In this step, we will see the rough shape of universal joint cross. Then, remove the flash under trimming dies by punching machine. Finally, polishing them into shot blasting machine with 0.3-0.5mm steel ball under 15-20 minutes. Now, the forged universal joint cross is completed.
Of course, for further assembly, machining will be operated on these forged universal joint crosses.
Any purchasing demand on forging and machining universal joint cross, pls contact us!