Couplings are also called couplings. A mechanical component used to firmly couple the driving shaft and the driven shaft in different mechanisms to rotate together and transmit motion and torque. Sometimes it is also used to connect shafts and other parts (such as gears, pulleys, etc.). It is often composed of two halves, respectively connected by keys or tight fits, fastened at the ends of the two shafts, and then connected by some means. The coupling can also compensate for the offset between the two shafts due to manufacturing and installation, deformation during work, or thermal expansion (including axial offset, radial offset, angular offset or comprehensive offset); And ease the impact, absorb vibration.
Most of the commonly used couplings have been standardized or standardized. Generally, it is only necessary to correctly select the type of coupling and determine the type and size of the coupling. If necessary, the load capacity check calculation can be carried out on the vulnerable and weak links; when the speed is high, the centrifugal force on the outer edge and the deformation of the elastic element can also be checked, and the balance check can be carried out.
Couplings can be divided into two categories: flexible couplings and rigid couplings.
Among the couplings, there is a part that is flexible and deformable. When connecting two rotational axes, some misalignment of the two rotational axes is allowed, ie a dynamically deformable coupling. The use of flexible couplings will reduce the accuracy requirements of alignment, facilitate testing, and have good shock absorption in the case of unstable rotational speed. But it has a disadvantage, because its material is rubber, nylon, etc., so its strength is low, its life is short, its bearing capacity is small, it is not resistant to high and low temperatures, and it is only suitable for low temperature occasions.
Plum blossom coupling
The plum blossom coupling is a widely used coupling, also known as the claw coupling, which consists of two metal claw discs and an elastic body. The two metal claw plates are usually 45 steel, but aluminum alloys are also useful where load sensitivity is required. Its elastomer is usually composed of engineering plastics or rubber. The lifetime of the elastomer is the lifetime of the coupling. The lifetime of the elastomer is 10 years. Since the elastic body has the function of cushioning and reducing vibration, it is widely used in the case of strong vibration. The limit temperature of the elastomer determines the service temperature of the coupling, usually -35 to +80 degrees.
Elastic column coupling
An elastic post coupling is a pin made of some non-metallic elastic material that is placed in the flange holes of the coupling halves. Through this pin, two half-couplers can be connected. The structure of the coupling is simple and easy to manufacture. It is convenient to install, remove and replace the elastic element without moving the two couplings.
Spring-loaded couplings transmit motion by welding or connecting corrugated thin-walled tubing directly to the coupling halves. The spring coupling has the advantages of simple structure, small size, convenient processing and installation, and high transmission precision. They are mainly used in small power precision machinery and control mechanisms that require compact structure and high transmission accuracy.
Universal joint coupling
The universal joint coupling uses the characteristics of its mechanism so that the two shafts are not on the same axis, and there is an angle between the shafts. It enables continuous rotation of two axes and reliably transmits torque and motion. The biggest feature of the universal joint coupling is that its structure has a large angle compensation capability and a compact structure, but compared with other couplings, its transmission efficiency is not very good. The angle between the two shafts of universal joint couplings of different structural types is different, usually between 5-45.
Rigid coupling, as the name suggests, a rigid coupling is actually a torsionally rigid coupling. Even under load, there is no cornering clearance. Rigid couplings are rigid to transmit torque even in the presence of load-producing misalignments. Rigid couplings are required to connect two shafts in strict alignment without relative misalignment, so they are less commonly used in motor test systems. Of course, if the relative displacement can be successfully controlled (alignment accuracy is high enough), rigid coupling can also play an excellent role in the application. Especially small size rigid couplings have the advantages of light weight, ultra-low inertia and high sensitivity. In practical applications, rigid couplings have the advantages of being maintenance-free, super oil-resistant and corrosion-resistant.
Several sets of diaphragms (stainless steel plates) are interleaved with the two coupling halves by bolts. Each set of diaphragms consists of multiple components, which are divided into connecting rods and entire diaphragms of different shapes. Membrane coupling compensates the relative displacement of the two axes through the elastic deformation of the diaphragm. It is a high performance elastic coupling with strong metal elements. It does not require lubrication, has a compact structure, high strength, long service life, no rotation gap, and is not affected by temperature and oil pollution. It has the characteristics of acid resistance, alkali resistance and corrosion resistance, suitable for high performance. Shaft transmission has working conditions of high temperature, high speed and corrosive medium. In terms of structural features, it has an insurance link. When the actual load exceeds the predetermined load, the diaphragm will break, cutting off motion and power transmission, thereby protecting the rest of the machine from damage and playing a role of safety protection.