The Transactions of the Korean Institute of Electrical Engineers D (대한전기학회논문지:시스템및제어부문D)

The Korean Institute of Electrical Engineers (대한전기학회)
권호 표지

Characteristics of the Sealing Pressure of a Magnetic Fluid Shaft Seal for Intra-Cardiac Axial Flow Blood Pumps

심장 내 이식형 축류 혈액 펌프용 자성 유체 축봉의 내압 특성

  • 김동욱 (순천향대학교 정보기술공학부) ;
  • Published : 2002.10.01
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Abstract

One of the key technologic requirements for rotary blood pumps is the sealing of the motor shaft. A mechanical seal, a journal bearing, magnetic coupling, and magnetic suspension have been developed, but they have drawbacks such as wear, thrombus formation, and power consumption. A magnetic fluid seal is durable, simple, and non power consumptive. Long-term experiments confirmed these advantages. The seal body was composed of a Nd-Fe-B magnet and two pole pieces; the seal was formed by injecting magnetic fluid into the gap (50${\mu}m$) between the pole pieces and the motor shaft. To contain the ferro-fluid in the seal and to minimize the possibility of magnetic fluid making contact with blood, a shield with a small cavity was attached to the pole piece. While submerged in blood, the sealing pressure of the seal was measured and found to be 31kPa with magnetic fluid LS-40 (saturated magnetization, 24.3 KA/m) at a motor speed of 10,000 rpm and 53kPa under static conditions(0mmHg). The specially designed magnetic fluid seal for keeping liquids out is useful for axial flow blood pumps. The magnetic fluid seal was incorporated into an intra-cardiac axial flow blood pump.

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References

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