Magnetic couplings are used to transmit rotational and/or linear motion without direct contact and we have significant experience in designing:
Rotary couplings
Linear couplings
Hysteresis couplings
Eddy current couplings
Rotary couplings are principally used to eliminate the use of seals in rotating and reciprocating machines, such as seal-less pumps and pistons. Use of magnetic couplers improves the reliability and safety aspects of such machines because seals are prone to deterioration over time and cause leaks.
Rotary magnetic couplers used in these applications are designed in two configurations - co-axial and face-to-face.
In the co-axial configuration, the two halves of the coupler are mounted co-axially with each other and nested one within the other. The outer member is typically connected to the motor and the inner member to the driven system, for example, the pump in a seal-less pump. A cup-shaped stationary member, mounted to the pump body, resides between the driver and follower and separates the fluids on the pump side from the environment on the motor side. Materials for the barrier cup and exposed surfaces of the follower are chosen to survive continuous contact with the fluids being pumped. The thickness of the barrier is designed to withstand any pressure differential without significant deformation.
Face-to-face type couplings are used where axial length is at premium and some misalignment needs to be tolerated. The two pancake-shaped parts comprising this type of coupler have magnets mounted on the near faces. The separation barrier in this case can be as simple as a flat wall. One aspect of face-to-face type couplings is considerable attraction between the two members.
Linear and rotary magnetic couplings, and hybrids of the two, also find application in vacuum technology where position or motion must be transmitted across a vacuum barrier. An added consideration in these applications is stiffness of the coupling; minimizing the lag between driver and follower.
Linear magnetic couplings, following similar principles, allow precise control of robotics inside vacuum systems. These couplers are used in the semiconductor industry to position objects within a clean chamber. Elimination of seals and reduction of the number of components inside the chamber improves contamination control and enhances system reliability.
