Performance of Magnetic-Superconductor Non-Contact Harmonic Drive for Cryogenic Space Applications Articles uri icon

authors

  • PEREZ DIAZ, JOSE LUIS
  • DIEZ JIMENEZ, EFREN
  • VALIENTE BLANCO, IGNACIO
  • CRISTACHE, CRISTIAN
  • ALVAREZ VALENZUELA, MARCO ANTONIO
  • SANCHEZ GARCIA-CASARRUBIOS, JUAN
  • FERDEGHINI, CARLO
  • CANEPA, FABIO
  • Hornig, Wolfgang
  • CARBONE, GIUSEPPE
  • PLECHÁCEK, JAN
  • AMORIM, ANTONIO
  • Frederico, Tiago
  • Gordo, Paulo
  • Abreu, Jorge
  • SANZ, VIOLETA
  • RUIZ NAVAS, ELISA MARIA
  • MARTINEZ ROJAS, JUAN ANTONIO

publication date

  • July 2015

start page

  • 138

end page

  • 156

issue

  • 3

volume

  • 3

International Standard Serial Number (ISSN)

  • 2075-1702

Electronic International Standard Serial Number (EISSN)

  • 2075-1702

abstract

  • Harmonic drives are profusely used in aerospace mainly because of their compactness and large reduction ratio. However, their use in cryogenic environments is still a challenge. Lubrication and fatigue are non-trivial issues under these conditions. The objective of the Magnetic-Superconductor Cryogenic Non-contact Harmonic Drive (MAGDRIVE) project, funded by the EU Space FP7, is to design, build, and test a new concept of MAGDRIVE. Non-contact interactions among magnets, soft magnetic materials, and superconductors are efficiently used to provide a high reduction ratio gear that smoothly and naturally operates at cryogenic environments. The limiting elements of conventional harmonic drives (teeth, flexspline, and ball bearings) are substituted by contactless mechanical components (magnetic gear and superconducting magnetic bearings). The absence of contact between moving parts prevents wear, lubricants are no longer required, and the operational lifetime is greatly increased. This is the first mechanical reducer in mechanical engineering history without any contact between moving parts. In this paper, the test results of a −1:20 inverse reduction ratio MAGDRIVE prototype are reported. In these tests, successful operation at 40 K and 10−3 Pa was demonstrated for more than 1.5 million input cycles. A maximum torque of 3 N·m and an efficiency of 80% were demonstrated. The maximum tested input speed was 3000 rpm, six times the previous existing record for harmonic drives at cryogenic temperatures.

keywords

  • magdrive; harmonic drive; magnetic gear; cryogenics; space mechanism; contactless device; superconducting magnetic bearings