Shaft Couplings

Shaft couplings are used to join or connect two shafts in such a way that when both the shafts rotate, they act as one unit and transmit power from one shaft to the other. Shaft couplings are classified as four types.
  1. Rigid Couplings
  2. Flexible Couplings
  3. Disengaging Couplings
  4. Non-aligned Couplings
In this post, I am going to give an idea about each type and few examples. 

RIGID COUPLINGS: Rigid shaft couplings are used for connecting shafts having collinear axes. These are further sub-classified into muff or sleeve couplings and flanged couplings.

1. Sleeve or Muff Couplings
    a. Butt Muff Coupling
    b. Half-lap Muff Coupling
    c. Split Muff Coupling
2. Flanged Couplings
    a. Flanged Coupling with Detachable Flanges
    b. Solid Flanged Coupling

FLEXIBLE COUPLINGS: Perfect alignment of two shafts is impossible to achieve and difficult to maintain, because of inevitable bearing wear and other reasons. To overcome the trouble, flexible couplings are employed. These permit relative rotation or variation in the alignment of shaft axes within certain limits. The following are the types of flexible couplings:

1. Bushed-Pin type Flanged Coupling
2. Compression Coupling

DISENGAGING COUPLINGS: Disengaging couplings are used when power transmission from one shaft to another is intermittent. With this, the shafts can be engaged or disengaged as and when required, even during rotation. A dis-engaging coupling in general consists of one part firmly fixed to the driving shaft and another one mounted with provision for sliding over the driven shaft. The part that is mounted on the driven shaft, can be made to slide at will to engage or disengage from the rotating driving shaft. The following are the examples of dis-engaging couplings.

1. Claw Coupling
2. Cone Coupling

NON-ALIGNED COUPLINGS: Non-aligned couplings are used to transmit power between two shafts which are not coaxial. The following are the examples of non-aligned couplings

1. Universal Coupling or Hooke's Joint
2. Oldham Coupling
3. Cushion Coupling

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