Retrofit Improved Powered Adjusting Mechanism

Goal

  • Improve reliability of a roll positioning mechanism by replacing dual coordinated servo motors with toothed belts with a single AC motor and a cross-machine synchronizing shaft. Fit entire new system in same space as original device.

Features

  • Retrofit designed to fit in existing crowded machine with only minor drilled and tapped holes to be added. No significant machine disassembly or rework required.
  • New cross-machine synchronizing shaft designed to pass through 2 existing holes in heavy 3” thick machine side frames originally used for power cables.
  • Simple conventional TENV AC motor drives a reducer that is shaft mounted on synchronizing shaft.
  • (2) shaft mounted right angle gear drives added to change direction of axis rotation and double as shaft supports.
  • Original toothed belt drives utilized with added belt tensioner for easier set-up.

Starting Point

The existing machine was about 15 years old and was in production. No dimensioned drawings for it were available.

Scope of Work

Field measurements were made to allow lay-out of the drive assembly and detailing and pre-manufacture of the required mounting brackets, etc. A 3-D Solid Works model was created of only the relevant parts of the existing machine. The new parts were modeled and manufactured for field installation.

Chill Roll retrofit Coating line.

Goal

  • An existing coating line for pre-preg cloth experienced material sticking to rolls downstream from a partial cure oven.  Chilled path rolls were proposed to cool the web to solidify the coating and prevent material sticking to rolls.

Starting Point

  • An existing tenter frame machine was to serve as mounting base for new rolls.   No drawings existed for the machine frame which was a radiused steel weldment.
  • Two rolls were to be mounted at the web exit elevation of the tenter to maximize roll wrap and cooling effectiveness.
  • One roll was to be mounted from overhead steel work to support the web after it traveled through an additional thermal process.

Features

  • Rolls and support brackets had to be sturdy to withstand factory environment and resist high tensions and aggressive cleaning methods.
  • Rolls supported in piloted flanged bearings allow roll removal and reinstallation without losing precision alignment.
  • Minimal shut down time could be accepted for installation.

Scope of work

  • AMD measured existing machine and created a 3-D model of only the relevant parts for the support structure and the adjacent downstream machinery.  The required web path was added to the model as were all new components such as rolls, bearings, and support structure.  A track mounted movable access ladder was also included in the model to ensure continued functionality after chill rolls were added.
  • New rolls were ordered per the design and custom brackets fabricated to fit to the existing machinery frame contour and over head steel work.
  • During 2 shifts the old machine frame was prepped, the new brackets were installed, aligned and welded securely.  Rolls were installed with new rotary unions, bearings, SS braided flexible hoses, and fluid temperature thermometers.

Calendar roll nip modification

Goal

  • Increase machine stiffness with suitable reinforcement.
  • Prevent roll lifting under load.
  • Provide repeatable precision roll gap adjustment.

Starting Point

A customer built calendar roll for casting a rubber sheet kept lifting under load.  Original closing mechanism was pneumatic but had been mechanically locked due to insufficient closing force.  Also repeatability of gap settings was unsatisfactory.  The existing machine needed stiffening and a precision calibrated gap adjusting stop added.  No drawings existed for the unit.  No quantifiable data existed as to actual loads.

Features

  • Precision high stiffness “wedge”  style adjustable stop retro-fitted.
    • Wedge has proprietary non-stick low wear plating to provide:
      • Long life
      • Lower adjusting effort
      • Prevent material build up & caking
  • Dial indicator added for repeatable and accurate gap setting.
  • A quick opening mechanical latch for closing the roll onto an adjustable stop.

Scope of work

Measure all relevant dimensions to allow design of retrofit parts. Estimate actual loads to ensure adequate stiffness. Design reinforcements to change load path and eliminate effect of frame distortion on roll gap. Design adjustable stop with high stiffness, high accuracy and easy repeatability.  Install retrofit without removing equipment from plant. On site work performed in only 1 shift.

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