Space-rated motors

MACCON can provide all types of electric motors and electro-magnetic designs for use in space:

  • Servo motors
  • Torquer and limited-angle torquer motors
  • Stepper motors
  • Reluctance motors (without magnets)
  • Hollow-shaft and thin-ring designs
  • Linear motors and voice-coil actuators
  • Rotary and linear solenoids
  • Motors, complete with housings, gear-boxes and bearings
    (lubrication to space standards)

Typically these motors are PM-BLDC 3- phase, multi-pole, brushless designs with inner rotors. However we also supply outer rotor motors and other technologies.

Contact us (Contact form) to discuss your needs with an experienced engineer!

MACCON motors and actuators for cryogenic temperatures

Most space programs require special motor designs, processes and materials. For these projects, classical industrial motor design approaches are not suitable. The individual design approaches, the material choice and manufacturing processes need to be qualified unless they are already verified by space heritage. To achieve long life and reliability, conservative and proven designs as well as the best possible quality levels of material and workmanship must be used. Further design requirements can be summarized as high efficiency, minimization of losses and heat dissipation by suitable a design architecture in order to reduce the influence of thermal stress on each component. Furthermore, special attention is needed, if a wide thermal operational range is required. In some extreme cases, temperature ranges for cryogenic applications are required. In such applications operating temperatures from around 70K up to a higher level of ambient conditions have to be managed. Therefore, the whole motor design has to be adapted to these extreme conditions by using special design rules. One example of a design rule for motors for cryogenic applications, is that the local coupling and contacting between individual motor phases in the stator winding must be minimized. This rule must be adhered to within the active part of the stator winding, but also within the end-turns, in order to minimize mechanical stress caused by unequal thermal expansion of the copper wiring, as well as to mitigate the effects of stress caused by the high vibration levels typical during a launch event. Furthermore, the choice of the lamination insulation varnish, as well as the wire and slot insulation material must be adapted to these harsh ambient conditions. In addition, the wire impregnating resin material and further stator components must be adjusted to these extreme requirements. For the rotor design special criteria must also be employed. The main issues of a cryogenically specified rotor design are the rotor architecture and the selected, high remanent magnet materials. A design with embedded rotor magnets may be the safest solution with regard to the mechanical stability and the protection of the magnets against demagnetization by strong stator fields. However, this approach is not conducive to maximizing the torque-to-volume ratio i.e. the torque density. A rotor design with surface-mounted magnets has a higher torque density than a design with embedded magnets. However, there are significant risks for the secure mechanical attachment of the magnets to the rotor hub due to thermal expansion stresses, not to mention centrifugal forces at high speed operation.

Please consult the scientific whitepaper on the above right for a detailed description of this technology.

MACCON engineering services around space-rated motors

In the following, we provide a list of typical engineering services which MACCON provides during the course of a space-rated motor project:

Motor-related services:

  • Photo documentation of rotor and stator for each manufacturing step
  • 3D measurement of each rotor and stator stack before manufacturing
  • Detailed Manufacturing Card
  • Minimum 5 key inspection points
  • Detailed Incoming and Outgoing inspections including photo documentation

Project management services

  • CIDL, ABCL
  • Control and Verification document, Compliance Matrix
  • DML and DPL
  • Manufacturing Flow Chart
  • CoC, User Manual
  • NCRs, RFC, RFD, RFW
  • KOM, PDR/CDR, MRR, TRR, DRB
  • Regular visits at Motor Manufacturer
  • Supplier management
  • Quality assurance
  • Regular conference calls
  • End Item Data Package

Detailed functional and performance testing services

  • Measurement of dimensions
  • Resistance and inductance measurement
  • Back-EMF measurement
  • Cogging torque measurement
  • Torque constant measurement
  • Operating point measurement
  • Test Procedure and Test Report

Thermal vacuum testing services

  • No-load motor operation under vacuum at a specified temperature
  • Stall torque under vacuum at a specified temperature
  • Temperature rise under vacuum at a specified temperature during stall torque test
  • TV Test Report

Vibration testing

  • Sine vibration rotor/stator in x, y and z axis
  • Random vibration rotor/stator in x, y and z axis
  • Vibration Test Report

Bake-out services

  • e.g. 72 hours under vacuum at 80┬░C

Feel free to contact us (Contact form) to discuss your needs with an experienced MACCON engineer!