Customer Objective
Cascon was approached by a leading supplier to the aerospace industry and U.S. space flight programs with a compelling challenge: the development of a pump to circulate ultra-low viscosity, high density heat transfer fluid in a cooling system for manned space flight applications. The customer’s development objectives for the pump called on Cascon to:
- Moderate costs by employing applicable commercial design strategies
- Design the pump for close integration with the overall system design
- Engineer the design for durability to withstand heavy shock and vibration loads
- Ensure reliability for the duration of an extended operational lifespan
Cascon Solution
The first step in any Cascon custom design and development effort is a clear understanding of the customer’s requirements. Experience gained over hundreds of design cycles has helped us develop a flexible and comprehensive requirements management system. The nearly 150 separate requirements for this critical application were tracked for clarity of understanding and compliance verification through the design and prototype phases of the program.
When this project began, neither Cascon nor the customer had experience with the unique heat transfer fluid, and there was little public domain data available on its tribiological properties. In an effort to ascend the steep learning curve, we commissioned an inexpensive 5,000 hour test using four existing Cascon pump models with design similarities to the customer’s specification.
Given its importance to the success of the project, Cascon worked to secure a brushless DC drive motor capable of withstanding extreme vibration and shock loads. Working through established relationships with trusted suppliers, we sourced a custom motor, constructed primarily with components and processes drawn from a commercial manufacturing line. This budget-friendly sourcing solution was then finalized with the introduction of traceability and process control parameters to satisfy the client’s strict requirements for manned space flight applications.
Cascon completed preliminary design review (PDR) and critical design review (CDR) presentations and reports to eliminate potential oversights, and to document any potential risks prior to prototype manufacture. We then manufactured prototype pumps for testing, analysis, and verification against project requirements and cost objectives.
Following the prototype phase, the first flight build was completed with minor design adjustments to accommodate requirement revisions, and to incorporate final improvements. The pump is slated for its first crewed spacecraft flight test in late 2019.
Pump Features
- Integrated design: Custom flange for direct manifold mounting, with an integrated inlet filter to conserve space and provide easy access.
- Precision stellite gerotor pump element: Reliable gerotor performance reduces weight while ensuring durability.
- Hybrid ceramic ball bearings: Precision design for reliable performance.
- High reliability 28 volt brushless DC motor: Tested technology ensures reliable operation under the most demanding circumstances.
- Durable HED sensor board: Designed to perform through continuous shock, vibration, heat and atmospheric changes.
Select Performance Parameters
Operating Voltage | 22 - 34 |
Pump Speed, Maximum (rpm) | 7,500 |
Fluid Type | Fluorinated Heat Transfer Fluids (e.g., Galden) |
Fluid Kinematic Viscosity (cSt) | <1 |
Rated Flow at Maximum Speed (gpm) | 1.5 |
Rated Pressure (psid) | 50 |
Shock and Vibration Environment | Severe |
Duty Cycle | Continuous, variable speed |
Operating Life Target (hours over 10 years) | 75,000 |
Size (in) | 2.78 sq. flange x 7.4 L |
Weight (lb) | ~2.5 |