Enclosure and acoustic damping

Purpose

• Reduce airborne noise emissions

• Contain flood coolant

• Provide operator protection

• Do not participate in the mechanical force loop

Enclosure construction

• Fully enclosed machine housing

• Construction from outside to inside:

  • MDF outer panels (mass)

  • automotive interior acoustic foam

  • thin inner sheet-metal liner

Inner liner

• Sheet metal sealed against coolant ingress

• Acts as washable and durable inner surface

• Treated with viscoelastic damping tape (e.g. 3M)

• Purpose:

  • suppress panel ringing

  • reduce tonal noise radiation

Acoustic strategy

• Mass-spring-mass principle:

  • MDF (mass)

  • foam (spring / absorber)

  • sheet metal (inner mass)

• Avoidance of large undamped flat panels

• No reliance on active noise cancellation

Mechanical integration

• Enclosure mechanically decoupled from machine frame where possible

• Enclosure does not contribute to stiffness or damping of the force loop

• Enclosure panels removable for service

Openings and airflow

• Openings minimized

• Any required airflow paths:

  • acoustically baffled

  • not line-of-sight for noise propagation

Design constraints

• Enclosure designed for apartment-compatible operation

• Noise reduction prioritized over cosmetic appearance