Correct selection of star coupling and precautions during maintenance

Published: 2018-08-25

The star coupling is a mechanical part used to connect two shafts (the driving shaft and the driven shaft) in different mechanisms so that they can rotate together to transmit torque.In the high-speed and heavy-duty power transmission, some star couplings also have the function of buffering, damping and improving the dynamic performance of the shafting.The star coupling is composed of two halves, which are respectively connected with the driving shaft and the driven shaft.The general power machine is mostly connected with the working machine by means of a star coupling.Therefore, sometimes in the process of installing the star coupling, we must pay attention to the deviation in the process of connecting the shaft to the shaft.The star coupling is composed of two halves, which are respectively connected with the driving shaft and the driven shaft.The general power machine is mostly connected with the working machine by means of a star coupling.Therefore, sometimes in the process of installing the star coupling, we must also pay attention to the deviation in the process of connecting the shaft to the shaft. It has a beautiful surface and good performance. It does not need to go through the surface treatment such as coloring, but the inherent surface performance is used. A kind of steel in many aspects, usually called stainless steel.High-alloy steels such as 13 chromium steel and 18-chromium nickel steel are representative of performance.From a metallographic point of view, because stainless steel contains chromium, a very thin chromium film is formed on the surface. This film isolates the role of oxygen intruding into the steel.

The star coupling has a simple structure (composed of four pieces), convenient assembly and disassembly, no need to move the connected two shafts when disassembling, compact size, light weight, compensation capability, low requirements for installation accuracy, longer work and longer life The advantages of long, low cost, etc., are widely used in various important structural parts in quenching and tempering treatment, especially those connecting rods, bolts, gears and shafts that work under alternating loads.The rectangular spline is characterized by high centering accuracy and good centering stability.For the taper hole to facilitate the installation and disassembly relative to the ordinary shaft, the key link star coupling is a mechanical part used to connect two shafts (the driving shaft and the driven shaft) in different mechanisms so that they can rotate together to transmit torque.In the high-speed and heavy-duty power transmission, some star couplings also have the function of buffering, damping and improving the dynamic performance of the shafting.

The correct choice of star coupling

1. The performance and working environment of the star coupling.Star couplings usually made of metal elements that do not require lubrication are better; star couplings that require lubrication are easily affected by the degree of lubrication and may pollute the environment.Star couplings containing non-metallic components such as rubber are more sensitive to temperature, corrosive media and strong light, and are prone to aging.

2. The size and nature of the torque to be transmitted and the requirements for the buffer and vibration reduction function.For example, for high-power and heavy-duty transmissions, toothed star couplings can be used; for transmissions that require severe impact loads or shaft torsional vibrations, tire-type star couplings and other highly elastic star couplings can be used. Shaft.

3. The magnitude and direction of the relative displacement of the two axes.When it is difficult to keep the two shafts in strict alignment after installation and adjustment, or when the two shafts will have a large additional relative displacement during the working process, a flexible star coupling should be used.

4. The manufacture, installation, maintenance and cost of star couplings.Under the premise of meeting the convenience of performance, a star coupling that is convenient for assembly and disassembly, simple maintenance, and low cost should be selected.

5. The working speed of the star coupling and the centrifugal force caused by it.For high-speed transmission shafts, star couplings with high balance accuracy, such as diaphragm star couplings, should be used, and eccentric slider star couplings should not be used.

Deviation description of star coupling

1. The star coupling can transmit torque and rotation angle, and can absorb shaft installation deviation. When the installation deviation exceeds the allowable value, it may cause vibration or shorten the life of the star coupling, so deviation adjustment is required appropriate.

2. There are three kinds of shaft deviation: one is radial deviation, that is, the two shafts are parallel but the lines are no longer on the same straight line. The deviation produced at this time is called radial deviation; the other is angular deviation, that is, the two shafts form one with each other. The deviation caused by the angle; the third type is the axial deviation, that is, the deviation caused by the reciprocating micro movement of the two axes.

3. The allowable value of large deviations listed in each product refers to the case where only one deviation exists, and when two or more deviations exist at the same time, the allowable value should be less than 1/2 of the large deviation in each specification table.

4. Deviations do not only occur in the assembly of the equipment. Factors such as vibration, thermal expansion, and bearing wear during the working process will cause deviations.Therefore, it is recommended to adjust the axial deviation to less than 1/3 of the maximum value.

Matters needing attention in overhaul of star coupling

1. The basic requirements for its inspection: the connection must be stable, the connecting bolts and connecting keys must not be loosened, and the radial and end surface jumps in the transmission should not be obvious when visually inspected. When using the instrument to check, it cannot be greater than.

2. Gear-type stability inspection: It needs to be removed for inspection when the transmission noise increases or the product is overhauled.

3. Elastic inspection: When the rubber ring and the leather pad are damaged, they need to be replaced as soon as possible. If the pin still has a hole to be destroyed and vibration occurs, it is necessary to drill a hole at an angle of the half body rotation. , Replace the standard new pin, it is not possible to expand the original hole with a new pin.

4. There are problems such as the sealing of the lubricating series oil, the deterioration of the oil, and the leakage of the oil.When the above situation occurs, the seal and oil need to be replaced. When the oil is lacking, it needs to be replenished as soon as possible.