Teach You How To Choose A Coupling (2)

The last article <Teach You How To Choose A Coupling (1) > talked about 1| coupling type and 2 | coupling function, next we continue to talk about 3 | coupling selection and 4 | coupling selection considerations. Hope it can help you.

3|Coupling Selection

Coupling selection should be based on magnitude of transmitted load, speed of shaft, mounting accuracy of two components being joined, and characteristics of various types of couplings.

Following aspects are usually considered when making specific choices:

1. Amount and nature of torque to be delivered and requirements for buffer damping. For example, for heavy-power heavy-duty transmissions, gear couplings are available; for severe impact loads or transmissions that require shafting torsional vibration, high-elastic couplings such as tire couplings are available.

2. Working speed of coupling and centrifugal force caused. For high-speed transmission shafts, couplings with high balance accuracy, such as diaphragm couplings, should be used, and it is not suitable to use eccentric slider couplings.

3. Magnitude and direction of the relative displacement of two shafts. Flexible couplings should be used when it is difficult to maintain a strictly accurate alignment of the two axes after installation adjustment, or when the two axes will produce a large additional relative displacement during operation; when radial displacement is large, optional slider coupling can be selected; universal coupling can be selected for joint with large angular displacement or intersecting two shafts.

4. Coupling reliability and working environment. In general, couplings made of metal components that do not require lubrication are relatively reliable; couplings that require lubrication are susceptible to the degree of lubrication and may pollute the environment. Couplings containing non-metallic components such as rubber are sensitive to temperature, corrosive media and strong light, are also prone to aging.

5. Coupling manufacturing, installation, maintenance and cost. Under the premise of satisfying performance of use, coupling with convenient assembly and disassembly, simple maintenance and low cost should be selected. For example, the rigid coupling is not only simple in structure, but also easy to assemble and disassemble, can be used for low-speed, rigid drive shaft. General non-metallic elastic component couplings (such as elastic sleeve pin couplings, elastic pin couplings, plum-shaped elastic couplings, etc.), because of their good comprehensive ability, are widely used in general medium and small power transmission.

4|Coupling Selection Considerations

At present, industrial industry generally has the improper selection of couplings. For example, gear couplings are widely used in shafting transmissions of metallurgical machinery and heavy machinery. In metallurgical machinery and heavy machinery low-speed heavy-duty shafting transmission, impact, vibration and two-axis offset are quite prominent disadvantages. Only flexible coupling with good damping and cushioning effect can improve working state of transmission system. Toothed coupling is a rigid, movable coupling for both drum and straight teeth.

Because it does not have function of damping and buffering and there are still a series of shortcomings such as regular lubrication, complicated manufacturing process and high cost, drum type gear coupling should be meshed (point contact) due to manufacturing error. The existence of all teeth is impossible to engage and bearing capacity is a theoretical value. When choosing a coupling, designer should choose coupling from perspective of shaft drive system and avoid simply selecting coupling from main and driven end connections.

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