Couplings are also called couplings.It is a mechanical component used to firmly connect 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, which are connected by a key or tight fit, respectively, and fastened to the ends of the two shafts, and then the two halves are connected in some way.The coupling can also compensate for the deviation between the two shafts due to inaccurate manufacturing equipment, deformation or thermal contraction during operation, etc. (including axial deviation, radial deviation, angular deviation or comprehensive deviation) ); As well as alleviate impact and absorb vibration.
Most of the commonly used couplings have been standardized or standardized. Under normal circumstances, it is only necessary to correctly select the type of coupling, and confirm the type and size of the coupling.When necessary, it can check the load capacity of the vulnerable thin links; check the centripetal force of the outer edge and the deformation of the elastic element when the speed is high, and perform the balance check.
What are the classifications of couplings
Couplings can be divided into two categories: flexible couplings and rigid couplings.
XNUMX. Rigid coupling
Rigid couplings are justified. In practice, rigid couplings are a way to change rigid couplings.Even if the load is received, there is no turning clearance.Even if there is a bias that generates the load, the rigid coupling is still rigid to transmit torque.Rigid couplings need to be used for strict alignment and connection of two shafts without relative misalignment, so they are less 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 the small size rigid coupling has the advantages of light weight, ultra-low inertia and high flexibility.In practical applications, rigid couplings have the advantages of maintenance-free, super oil and corrosion resistance.
XNUMX. Flexible coupling
Among the couplings, one part is flexible and deformable.When connecting two rotating shafts, a certain misalignment of the two rotating shafts is allowed, that is, a dynamically deformable coupling.The use of flexible couplings will reduce the accuracy requirements for alignment, facilitate testing, and have good shock absorption under conditions of unstable speed.But it has a defect. Because its materials are rubber, nylon, etc., its strength is low, its life is short, its load capacity is small, it is not resistant to high and low temperatures, and it is only suitable for low temperature places.
1. Plum blossom coupling
The quincunx coupling is a commonly used coupling, also called a claw coupling, which consists of two metal claw discs and an elastic body.The two metal claws are usually 45 steel, but aluminum alloys are also useful in situations where load flexibility is required.The elastomer is usually composed of engineering plastics or rubber.The life of the elastomer is the life of the coupling.The life of the elastomer is 10 years.Since the elastic body has the function of buffering and reducing vibration, it is commonly used in severe vibration conditions.The limit temperature of the elastomer determines the operating temperature of the coupling, which is usually -35 to +80 degrees.
2. Elastic column coupling
The elastic column coupling is a pin made of some non-metallic elastic materials, which is placed in the flange holes of the two halves of the coupling.Through this pin, two half couplers can be connected.The structure of the coupling is simple and easy to manufacture.Without moving the two couplings, it is convenient to disassemble and replace the elastic element.
3. Spring coupling
The spring coupling is welded or the corrugated thin-walled tube is directly connected to the two halves of the coupling to transmit motion.The spring type coupling has simple structure, small size, convenient processing device and high transmission accuracy.They are mainly used for small power precision machinery and control mechanisms that require compact construction and high transmission accuracy.
4. Universal joint coupling
The universal joint coupling uses the characteristics of its mechanism, so that the two shafts are not on the same shaft, and there is an angle between the shafts.It can complete the continuous rotation of the two shafts and transmit torque and movement firmly.The greater feature of the universal joint coupling is that its structure has a large angle compensation ability 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 construction types is different, usually between 5-45.
XNUMX. Membrane coupling
Several sets of barriers (stainless steel plates) are interwoven with two half couplings through bolts.Each group of barriers is composed of multiple components, which are divided into connecting rods and entire barriers of different shapes.The membrane is coupled through the elastic deformation of the membrane to compensate the relative displacement of the two shafts.It is a high-performance flexible coupling with solid metal elements.It does not require smoothness, 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 and is suitable for high performance.The shafting transmission has working conditions of 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 barrier will break, cutting off the movement and power transmission, so as to protect the other parts of the machine from damage and play a safe maintenance role.