The use and structure principle of hot-mounted cross shaft universal coupling

Update:31-12-2021
Summary:

Universal coupling, as a type of coupling, uses the cha […]

Universal coupling, as a type of coupling, uses the characteristics of its mechanism to make the driving shaft and the driven shaft not on the same axis. When there is an angle between the axes, the connected two shafts can rotate continuously and can transmit rotation. Moment and movement. Compared with ordinary couplings, the important feature of universal couplings is that the universal coupling structure has greater angular compensation capability, compact structure, and good transmission efficiency.

With its own performance, the market sales volume is considerable, and there are many types of universal couplings on the market. So how to choose the right coupling? Among them, the cross-shaft universal coupling is a universal coupling with a large amount, and the bearings of this universal coupling are easily damaged parts. Generally speaking, the car will use the ball cage universal coupling. For agricultural machinery, industrial machinery and other sports machinery, universal couplings are used, and cross-shaft universal couplings are mostly used for hoisting universal couplings.

 

First, preparation before hot loading
Fill the matching part of the journal and the cross shaft universal joint with gasoline or kerosene and scrub it clean. If there is roughness or damage, you need to use oilstone or fine diamond gauze to solve it, of course, other methods can also be used to deal with it. Then use a micrometer to measure the inner diameter of the journal, and a micrometer to measure the inner diameter of the cross shaft universal coupling. When measuring the coupling, measure at least 3 points and repeat the measurement. If the processing result does not meet the requirements of the drawing, use a scraper or a half-round file to repair the inner hole.

 

 

Second, hot loading
After preparing for the work, start the hot-installation. It is required to be fast, so as to avoid the temperature drop before the hot-installation is completed, which leads to the shrinkage of the aperture of the cross-shaft universal coupling, which makes it difficult to install. Generally, hot-fitting cross shaft universal joint universal joint will heat the temperature to 250 ℃. The heating temperature should not be too fast, so as not to affect the uniformity of the coupling temperature. As for the heating time, it should be determined according to its expansion. In order to obtain a reasonable inner diameter of the coupling, a measuring stick of the same size can be made according to the measured heating expansion value, and the measuring stick can be heated until the measuring stick can be put into the inner diameter hole. Then carry out the hot-sleeve work.

The surface of the cross universal joint should be carburized and quenched or tempered. The hardness of the obtained surface is different depending on the method. Gas carburizing puts the workpiece into a closed carburizing furnace, and passes gas or liquid carburizing agent to obtain a high-carbon surface layer. Solid carburizing is to put the workpiece and solid carburizing agent (composed of charcoal and accelerator) in a sealed box, and heat it to the carburizing temperature in a heating furnace, and keep it for a period of time, so that the activated carbon universal coupling atoms can infiltrate This is also the carburizing method for the surface of the workpiece.

It is a general-purpose component of mechanical foundation, and it is suitable for two shafts whose axis is skewed and whose relative position changes frequently. The advantages of the cross-shaft universal coupling are large transmission torque, angular compensation capability, and compact structure.

 

Structure principle:
The cross piece on the main and driven shafts and the middle cross shaft are respectively connected by hinges. When there is an angular displacement between the two shafts, the shaft forks rotate around their respective fixed axes, so that the cross shaft can move in space.

 

Motion analysis:
When the angle between the two shafts is not zero, the actual rotation angle between the rotation angle of the driving shaft and the rotation angle of the driven shaft at any instant: Moving shaft 3 is the movement of point C on the driven shaft fork.