Conventional pumps or compressors, particularly those which are employed in oxygen concentrators, exhibit a number of disadvantages. These pumps tend to be relatively large, heavy, noisy and inefficient. For example, a typically rotary compressor requires a rotor and other parts which add to the complexity, weight, noise and expense of the system. An unwieldy pump presents a particular problem for patients who require a concentrator because it severely limits the patient's mobility. Known oxygen concentrator compressors also typically require a 60 cycle alternating current power supply which may not be available in many countries. Moreover, the speed required by a conventional pump uses undesirable amounts of electricity and generates undesirably large amounts of heat. And, there is a certain degree of risk presented from potential sparks around high concentrations of oxygen. Conventional concentrators also require relatively complicated timing and valve connections, thereby further increasing their expense and their risk of malfunction.
A number of linear electromagnetic pumps are known for use in the respirator art. However, these devices still do not provide optimal efficiency. Virtually all require fairly sophisticated electromagnetic drives. Certain of these devices also require springs, cranks, crank arms and bobbins to develop compression. Such structure adds to the weight, complexity and unreliability of these systems. Moreover, excessive heat generation and electrical inefficiency again tend to be problems.