Universal Joint Cross Forging
The universal joint, also referred to as the UJ, is widely used in a range of machines and automobiles. It’s especially used in heavy-duty applications where uniform motion between several rotating shafts is needed. The joint is used to connect rigid shafts that are inclined to each other. That’s why they are widely used in automobiles, where motion uniformity is a crucial factor to consider. Because of the designs’ nature, these joints are widely used in shafts that transmit rotary motion.
The universal joint cross, or UJ cross, is one of the most complex joints and machine parts to manufacture. Unlike the typical parts, they have a complex 3D geometry feature that makes their production quite tricky. But with modern forging technology, the design and production process has been improved. Hot forging is one of the most popular forging technology for forming these parts.
The universal joint cross is now being hot forged. Hot forging is a forging process that works on a workpiece that has been heated. In most cases, the heating goes to 75 percent of the melting temperature. This temperature is also known as the crystallization temperature. At this temperature, the metal is also already having plastic deformation. This makes it easy to press the material to form the required shape and size.
But the process of producing the universal joint cross is a bit different from most of the hot-forged machine parts. From the types of forging to the materials used, these joints are unique. There are also various types of the universal joint cross, and each of them has a unique forging process. But the most common is the universal joint cross with journal pegs and bearing cases.
From the hot forging of the material, you need to machine, carburize in the furnace, and ground the parts to get the required size, among many other steps. To elaborate further, we have put down the process of forging these joints below:
For starters, a universal joint cross is produced under closed die forging. So, the first step to the production of these parts is developing the mold or the dies. The quality of the die matters because of two main things- the high impact of compression force and the high heat. So the metal forming the mold must be hard enough to withstand these conditions.
The second step is choosing the round bars of equal size. Cut them into the required length and heat them to almost their crystallization temperature before placing them to the forging press. Place heated cylinders under the forging mold and press for several seconds. At this point, what you will be having is the rough shape of the universal joint cross.
From this step, you need to carburize the joint in the furnace to increase its ruggedness and wear resistance. Before you can ground the parts, add some oil seal and dust cover to protect the internal journal from foreign materials. That’s another way of enhancing universal joint cross lifespan and reducing the rate of wear and tear. Finally, polish the part, and the universal joint cross is complete and ready for use.
There are several crucial factors that you need to consider when hot forging a universal joint cross. One of them is the material. Depending on the application of the UJ cross, you need a material that can withstand the condition. Similarly, you need a material that will withstand the forging process. With the tons of compression force and melting temperatures, the material must withstand such conditions.
The choice of the machine is also an important factor to consider. Depending on the material you are forming, you need a machine that will produce the required compression force. If the material forms at 40 tons, then the machine should be capable of producing that force.
Last but not least is the finishing work. The finishing that you have carried out determines several things, including the joint’s lifespan and effectiveness. The finishing should protect the joint from wear and tear problems such as rusting.
At Hot Forging China, we use forging technology to produce complex hot forged universal joint cross. We produce all types of universal joints at an affordable cost while still delivering the highest quality. Contact us today for mass production if you need large quantities of UJ cross and other types of joints.