Frameless Motor Mounting Practices: Bonding with Structural Adhesives

Embedded Motion Technology - Frameless  Mounting Considerations

• The benefits of Improved System Performance, Reduced Maintenance, Smaller Mechanical Footprint, Higher System Efficiency are understood
• Customer still has a key question in mind …  
• I like the frameless design concept but how do I mount the motor components into my machine?

Mechanical Mounting Considerations

• Customer’s own bearings
• Customer’s shafting / drivetrain
• Bearing precision and machining tolerances are dependent more on customer machine requirements than frameless motor mounting requirements
• Run-out more dependent on customer requirements
• Air gap of 0.015” – 0.075” (0.38 mm – 1.9 mm) each side   of rotor needed for frameless motor 
• Mounting; Bonding, Clamping, and Shrink fit options discussed in some detail in the KBM Selection Guide

Radial Running Clearance – “AirGap”

KBM-43X03 Mounting Example Bonding 1

KBM-43X03 Mounting Example Bonding 2

KBM-43X03 Mounting Example Bonding 3

KBM-43X03 Mounting Example Bonding 4

KBM-43X03 Mounting Example Bonding 5

• Recommended for KBM Frame size 118XX and smaller
• Recommended Structural Epoxy:
  • 3M Scotchweld 2214
  • Hysol EA934NA
• Design Recommendations
  • Cylindrical cup shape customer housing
  • Locating shoulder for precise location
  • Lead in chamfer to aid in assembly operation
  • Maintain clearance over potted winding surfaces > 2 mm
  • Slip fit with housing of 0.1-0.2 mm over stator OD max
  • Adhesive grooves with extra slip fit gap of 0.13-0.26 mm
  • Parts will “self-center” during cure by orienting in vertical axis
  • Maximum Cure temperature of 155 C to prevent insulation damage
• Please Note that:
  • Adhesive manufacture guidelines should be followed
  • Other adhesives can be used
  • Customer ultimately responsible for proper design of:
  • Housing dimensions accounting for thermal effects
  • Proper surface preparation and application of adhesive

KBM-43X03 Mounting Example Bonding 6

KBM-43X03 Mounting Example Bonding 7

KBM-43X03 Mounting Example Bonding 8

Mounting Considerations

Bonding with Structural Adhesives

• Bearing precision and machining tolerances are dependent more on customer machine requirements than frameless motor mounting requirements
• Structural adhesives represent a cost-effective, industry proven, and mechanically sound approach to frameless motor mounting
• Several mounting options; Bonding, Clamping, and Shrink fit options are discussed in some detail in the KBM Selection Guide