What Are the Different Types of Palm Couplings?

Palm couplings, also known as flexible couplings, are mechanical devices used to connect two shafts in order to transmit torque and accommodate misalignment between them. There are several types of palm couplings available, each with its own design and application. Here are some of the common types:
Jaw Couplings:
Jaw couplings are among the most popular and widely used flexible couplings. They consist of two metal hubs with concave jaws that engage with an elastomeric spider or insert placed between them. The elastomeric spider absorbs shock, handles misalignment, and transmits torque between the hubs.
Tire Couplings:
Tire couplings, also known as Tyre couplings, use an elastomeric tire-shaped element to connect two hubs. They provide high torsional flexibility and are commonly used in various industrial applications.
Grid Couplings:
Grid couplings use a flexible grid element made of metal or synthetic material to transmit torque between the hubs. They offer good shock absorption, misalignment tolerance, and are often used in demanding applications.
Bellows Couplings:
Bellows couplings consist of two hubs and a thin-walled metal bellows. They are highly flexible and suitable for applications requiring precise positioning and minimal backlash.
Oldham Couplings:
Oldham couplings utilize three parts: two hubs and a center block with slots that fit together. These couplings accommodate axial, radial, and angular misalignment while maintaining constant velocity transmission.
Disc Couplings:
Disc couplings employ a series of thin, flexible metal discs that are stacked alternately and bolted between two hubs. They provide high torsional stiffness and can handle misalignment.
Universal Joints (U-Joints):
Universal joints, often called U-joints, consist of a cross-shaped yoke connected to two shafts with needle bearings. They allow for angular misalignment and are often used in drivetrains and steering systems.
Rigid Couplings:
While not flexible like other palm couplings, rigid couplings provide a solid and stiff connection between two shafts, ensuring accurate shaft alignment. They are used when misalignment is minimal or unwanted.
Pin and Bush Couplings:
Pin and bush couplings consist of two hubs with pins that engage with bushings. They are simple and cost-effective but offer limited misalignment tolerance compared to other types.
Magnetic Couplings:
Magnetic couplings use magnets to transmit torque through a non-contact mechanism. They are commonly used in applications where leak-proof seals are required, such as pumps handling hazardous fluids.
The choice of palm coupling depends on the specific requirements of the application, including torque transmission, misalignment tolerance, speed, and environmental conditions. Different couplings offer varying degrees of flexibility and rigidity to suit the needs of different industries and machinery.