MSD I Action Items
Action Item 1: Lubrication System Redesign
Upon completion of MSD I, our team received feedback from our technical support at Dresser Rand pertaining to the oil flow rate of our lubrication system. He recommended recalculation of our oil flow rate based on desired test bearing pressure as the current value seemed low compared to what is seen in the field.
The recalculation indeed revealed a higher flow rate and as a result, it was recommended we consider the use of a gear pump as opposed to the staging pump included in our initial system design. This change may also require a back pressure valve to be included as well.
The lubrication system has been redesigned to ensure it can operate over a broad range of conditions. The pressure setting has been increased to 0-150 psi (MSD1 system only allowed up to 30 psi), the flow rate has been increased to ~1.5 GPM (at 50 psi benchmark), the routing system has been hardened to allow for more severe testing (>150 psi if relief valve is changed out), and important sensors have been added (pressure and flow) to collect important test data. The new system is a significantly stronger system that will be able to support both static loading tests and severe duty dynamic testing.
Action Item 2: Single Axis Mechanical Loading System Design
Upon completion of MSD I, it was determined that the Dynamic Loading System would be completed in a later phase of the project due to personnel and cost issues. In the meantime, a Static Loading System would be constructed in its place. The Static Loading System is to maintain the same load range as the future Dynamic Loading System.
Initially, a two axis pneumatic loading system was proposed to provide static loads with the option of staging (time based step load profiles). However, since this load application system will only serve temporarily and then be discarded, it was determined that the team would pursue a single axis mechanical loading system.
A hanging weight lever arm static loading system was chosen for its simplicity in concept, analysis, and design. Analysis of the system is available in the link above.
Action Item 3: Test Bearing Housing Redesign
After the MSD I Gate Review, the team had some growing concerns pertaining to the three piece test bearing housing. The housing had been designed with the intent of fostering quick bearing change-out. However, it was determined that the stack up could create "slop" as a result of improper assembly or manufacturing. As a result, the team opted to explore a single piece test bearing housing option.
For the reasons indicated in the above PUGH Analysis, the single piece test block will be pursued.
The new test block design has several key advantages over the two part housing for static testing. The seamless housing means that there is a perfect surface to install oil-seals which will keep dirt out and oil in, protecting the bearing, test rig, and surrounding equipment. Additionally the single piece design allows for more accurate readings due to decreased slop or pre-loads that occur in multi-component assemblies. Finally for the current iteration of the project the single piece housing will not cause bearing placement, replacement, or removal times to increase significantly.