The advantages of elastic couplings compared with other couplings

Published: 2020-10-31

The elastic coupling has general shock absorption and certain two-axis offset compensation capabilities. It should be used in situations where the forward and reverse rotations are changeable and frequent starting.Flexible couplingIt is suitable for coaxial transmission shaft system. It uses the cross-sectional shear strength of nylon rod to transmit torque and has a certain ability to compensate shaft deviation.The pin in the elastic coupling shaft is in shearing and squeezing state when working, and its strength condition is to calculate the shear strength of the elastic pin cross section and the squeezing strength of the pin and the pin hole wall.

The elastic coupling is made of several non-metallic elastic material pins, which are placed in the flange holes of the two halves of the coupling, and the two halves of the coupling are connected by the pins. The coupling has a simple structure and is easy to manufacture. It is more convenient to assemble, disassemble and replace the elastic element without moving the two couplings.The material of the elastic element (column pin) is generally selected from nylon, which has the ability to compensate the deviation of the two axes in a small amount. The elastic part is sheared when working, and the working reliability is extremely poor. It is only suitable for the medium-speed transmission shaft system with very low requirements. For working conditions with high reliability requirements, such as the transmission shaft system of the lifting mechanism of a hoisting machine cannot be selected.

The diaphragm coupling is composed of at least one diaphragm and two shaft sleeves. The diaphragm is fastened to the shaft sleeve with a pin and generally will not loosen or cause backlash between the diaphragm and the shaft sleeve.Some manufacturers provide two diaphragms, and some provide three diaphragms, with one or two rigid elements in the middle, and the two sides are connected to the shaft sleeve.The characteristic of the diaphragm coupling is a bit like a bellows coupling, in fact the way the coupling transmits torque is similar.

The diaphragm itself is very thin, so when the relative displacement load is generated, the diaphragm coupling is easy to bend, so it can withstand up to 1.5 degrees of deviation, and at the same time produce a lower bearing load in the servo system.Diaphragm couplings are often used in servo systems. Diaphragms have good torque rigidity, but are slightly inferior to bellows couplings.The diaphragm coupling is very delicate and can be easily damaged if it is misused or improperly installed in use.Therefore, it is very necessary to ensure that the deviation is within the tolerance range of the normal operation of the coupling.In the newly designed transmission system, seven types of shaft holes that meet the requirements should be selected to improve versatility and interchangeability. The length of the shaft hole is in accordance with the requirements of the bearing coupling product standard.

Compared with other couplings, the elastic coupling is stable and reliable, with good vibration reduction, buffering and electrical insulation properties; simple structure, small radial size, light weight, small moment of inertia, suitable for medium and high speed occasions; elastic coupling The shaft unit has large axial, radial and angular compensation capabilities; the high-strength polyurethane elastic element is wear-resistant and oil-resistant, has a large load-bearing capacity, long service life, and is reliable; the elastic coupling does not require lubrication, requires less maintenance, and can be continuous Long-term operation.

The elastic coupling is fixed by positioning screws, and the gap between the two positioning screws is 90° to lock the shaft of the fixed coupling. In the traditional fixing method, because the front end of the screw contacts the shaft, it may cause damage or damage to the shaft. Difficult to disassemble.The clamping screw fixation is to use the tightening force of the hexagon socket bolt to shrink the slit and clamp the shaft tightly.This method is convenient to fix and disassemble, and will not cause damage to the shaft, so it is a very common fixing method.Keyway type fixing is suitable for high-torque transmission. To prevent axial sliding, it is usually used together with set screw fixing and clamping screw fixing.

The elastic coupling has the properties of compensating the relative deviation of the two shafts, cushioning, shock absorption, and abrasion resistance. It is suitable for general occasions. The elastic coupling is made of polyurethane plastic and the working temperature is -35~+80 degrees.The polyurethane elastomer is limited by the convex claw block, which can avoid internal deformation caused by impact and external deformation caused by centrifugal force; the large concave surface of the convex claw makes the surface pressure on the involute tooth very small, even if the tooth is overloaded , The teeth will not wear or deform.Shock and vibration, ambient temperature and humidity range, presence of oils, solvents, corrosive liquids, steam, sand, dust, salt water and radiation.