Date of Award

8-2016

Degree Type

Thesis

Degree Name

Master of Science in Agricultural and Biological Engineering

Department

Agricultural and Biological Engineering

First Advisor

John H. Lumkes

Committee Chair

John H. Lumkes

Committee Member 1

Gregory M. Shaver

Committee Member 2

Andrea Vacca

Abstract

Most valves available in the fluid power industry today are capable of achieving either a large flow rate or a quick response time; however, often they are unable to deliver both simultaneously. Commercially available valves that can produce both at the same time require complex geometries with multiple actuation stages and piloting pressures, making them expensive components. To establish their active usage in applications across the fluid power industry, a reduction in price for these components is paramount. The Energy Coupling Actuated Valve (ECAV) is capable of solving the large flow rates with fast actuation speeds trade-off by utilizing a new, high performance actuation system. The Energy Coupling Actuator (ECA) is an innovative actuation system that separates the kinetic energy source mass from the actuation mass. Intermittently coupling the actuator to a constantly rotating disk creates an energy transfer from the rotating disk’s kinetic energy to the normally stationary actuator. This intermittent coupling process is controlled by changing the magnetic field inside the actuator’s two coils. Magnetorheological (MR) fluid resides in a 0.5mm fluid gap between the spinning disk and the actuator, and when the magnetic flux builds across this gap, it causes the actuator to move rapidly in a translational movement. The MR fluid changes to a solid between the gap and frictionally binds the actuator to the disk, causing the actuator to move up or down, depending on which coil is actuated on the spinning disk. The liquid-solid conversion from the MR fluid occurs in less than one millisecond and is completely reversible. The shear strength of the fluid is proportional to the magnetic field strength inside the system. The actuator is connected to either a poppet or spool assembly for valve actuation, and the position is controlled through intermittently binding the actuator to the disk.

Two valve prototypes, one poppet and one spool type, were machined, and concept validation has been done in both simulation and experimentally. Experimental results show that the poppet reaches a 4mm displacement in 19.8ms opening and 17ms in closing under 33 L/min flow. The spool valve experimentally transitioned in 4.8ms at the same flow rate.

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