Table of Contents
|Safety & Ergonomics||3||Capacity to prevent work-related injury|
|Cost||2||Upfront Purchase/Installation Cost (capital investment)|
|Transportability||2||Ease of Motion|
|Current Capability||1||Compatibility with current facilities|
|Scale||3||Impact of installation, no monuments allowed|
|Guidance||2||Ability to remain inline|
|Flexibility||3||Capacity for systems integration|
|Maintenance||2||Operational Cost, Frequency of Repairs, Repair Costs|
|Returnability||2||Ability to return empty fixture to beginning of the line|
|Ease of Use||3||Minimize worker frustration, encourage proper use of the system|
House of QualityHow our specifications map to our customer needs
Concept Development (generation, improvement, selection)
Moving the Compressor
Propelling the Compressor
Lifting the Compressor
Design #1: Caster System (MSD I)
During MSD I, the team focused on designing a caster system that would be easy to construct and very flexible. A systems level and preliminary detailed design were completed. A tabletop prototype was also built and presented. This was the first design generated because our recommendation to use air bearings was not approved until finals week of MSD I.
Initial Cart Design
Once weight and CG parameters were established, the cart was designed to be 90" wide and 18" high. Singularity functions from Shigley's Mechanical Engineering Design were used to size a beam with a factor of safety over 2.
Cart CAD Models and Description
The original risk assessment and mitigation plan at the systems design level:
Based on direction received from Dresser-Rand, RIT faculty, and our guide, the risk assessment from the systems design level has been revised to include more technical risks related to specific solution(s) chosen to pursue. Please click the link below for the latest version:
Caster System Design Review
See the Detailed Design page for further design of the caster system.
Design #2: Air Bearing System (MSD II)
Air bearings were approved Week 11 of MSD I, leading the team to a new design path. The goals of this design work will be a systems and detailed level design with the possibility of a prototype, time permitting.
Free SystemThe Free System describes a modular slave frame similar to the original caster system. The slave frame remains fixed to the compressor, but is not rigidly connected to the floor at any point. This slave frame is simply a structural frame to hold the compressor at working height. An air pallet must be used to translate the compressor and frame.
Free System Walkthrough
- Step 1: Compressor Frame is loaded onto Free slave frame system.
- Step 2: Air pallet is slid under the Free slave frame system using integrated casters.
- Step 3: Air pallet inflates allowing free movement
- Step 4: Air pallet is moved to next station
- Step 5: Air pallet is deflated and removed from under Free slave frame.
- Step 6: Repeat as necessary
The Fixed System is a modified version of the previously mentioned Free System. The main difference in this design is that the vertical “legs” are now fixed to the floor at each station, reducing the system frame to singular horizontal beams. Like the Free System, the Fixed System is simply a structural frame to hold the compressor at working height – an air pallet is still required to move the compressor from station to station.
Step 1: Horizontal beams are placed on the loading station
Step 2: Compressor frame loaded is onto and fixed to horizontal beams
Step 3: Air pallet is slid into the fixture using integrated free rolling casters
Step 4: Inflation of the air pallet lifts the horizontal beams and compressor frame free of the fixture, allowing movement to the next station.
Air Pallet Research
After meeting at Dresser Rand with a representative from Airfloat, the concept of a slave pallet system was proposed. This system incorporates only one air pallet for all compressors on the line. The air pallet would only provide the movement between stations and would not accompany each compressor throughout the line as our previous caster design would. The 'slave' pallet would then be a secondary system that would support the compressor and move with it through the line.
Both the above designs incorporated this 'slave' pallet idea. After receiving some information from Airfloat with regards to the sizing of the air pallets we decided to model our design based on a pallet width of 40 inches. This makes our 'slave' system, consisting of two beams across the width of the pallet and underneath the compressor supported by sunken posts when at rest, totaling a width of 50 inches.
Air Pallet System Design Review
Location: Dresser-Rand, Painted Post
- Design decision for air bearing free frame or fixed frame system
- Layout decision for U-shape or straight-line with finer details
FeedbackAfter talking through the pros and cons of both the fixed and free slave frame systems, DR recommended our efforts be put into finalizing the fixed system on a systems design level. The free system was discouraged, however the presentation of multiple options was appreciated.
See the Detailed Design page for further design of the air pallet system.