The working principle and selection conditions of universal coupling

With the continuous development of social science and technology, the technology of universal joints is also constantly improving, and universal joints are widely used in various fields. Universal couplings include cross shaft type, ball cage type, ball fork type, concave and convex type, ball pin type, ball hinge type, ball hinge plunger type, three pin type, three ball pin type, hinge rod type, etc. The most commonly used type is the cross shaft type, followed by the ball cage type. In practical applications, it can be divided into heavy, medium, light and small according to the torque transmitted. In order to select a coupling suitable for the prime mover from the many universal joints, it is necessary to have a deep understanding of the operating conditions and external influences.

The working principle of the universal joint is as follows:
1. The universal coupling utilizes the characteristics of its mechanism, so that the two shafts are not on the same axis, and when there is an angle between the axes, the connected two shafts can be rotated continuously, and the torque and motion can be transmitted reliably.

2. The biggest feature of the universal coupling is that its structure has large angular compensation ability, compact structure and high transmission efficiency. Different structural types of universal joints have different angles between the two axes.

3. Mechanical parts used to connect two shafts in different mechanisms to rotate together to transmit torque. In high-speed and heavy-load power transmission, some couplings also have buffers to reduce vibration and improve the dynamic performance of the shaft system. effect.

4. The coupling is composed of two halves, which are respectively connected with the driving shaft and the driven shaft. Generally, the power machine is mostly connected with the working machine by means of the coupling.

5. The cross-shaft universal coupling is a universal coupling with a large amount, and the bearing is the wearing part of the cross-shaft universal coupling. The main difference between several large cross-shaft universal couplings It depends on the change of bearing seat and cross head to form different structural forms.

Prerequisites and conditions for purchasing universal joints:
1. Whether there is a transmission device between the prime mover and the universal coupling. If there is a transmission ratio, it will be output by several shafts after passing through the intermediate transmission device, that is, whether there is a power split. Consider the type, power and speed of the prime mover.

2. The type of prime mover and the load type of the cross shaft universal coupling need to be considered: one-way constant load, pulsating load or two-way alternating load. How is the installation status of the universal joint? Horizontal, vertical or inclined installation. Try to make the shaft angle less than 3 degrees. If you need to install it obliquely, you should determine the horizontal and vertical angles.

3. Considering the working environment of the prime mover, whether it is affected by harsh environmental conditions such as high temperature, dust, water spray, chemical corrosion, etc., select the corresponding type of universal coupling according to different use environments.

4. It is necessary to know the connection form and specific installation size required at both ends of the universal coupling, and whether there are special requirements such as installation brackets.

5. What is the rotational speed of the cross shaft universal coupling itself? Whether dynamic balancing is required. Need dynamic balance or balance, which level of balance quality is needed.

6. Is there any restriction on the installation location. What is the specific installation length, and whether it needs to be expanded or contracted. When expansion and contraction is required, how much does the universal joint extend outward in the shortest state? For universal couplings that do not require expansion and contraction, the compensation of axial dimensional errors must be considered, and the position of the compensation in the system must be determined. Through the understanding of the above prerequisites, the specifications of the universal joint shaft are gradually determined, and which structural form is finally selected.