Fluid Flow Control Valve
Description of Market Need:
Valves are necessary to operate pneumatic and hydraulic systems. Industrial valve market was valued at USD 67.5 billion in 2017 and is expected to reach USD 85.2 billion by 2023. A gap exists in the current advanced valve market as there are no electronically-controlled proportional flow control valves that are: small (<40 cm3), compact, lightweight (<30g), cost-effective (~$10 USD), robust, easily-customizable, fast (<70ms to fully close or open), that can support flows (>2.5 l/min and >0.2 Ml/min for water and air respectively) and pressures (>100 PSI or 0.7 MPa). The Compact Robotic Flow Control (CRFC) Valve, addressed here, was created to resolve these market shortcomings. It can be used in fluid applications in wearable assistive, rehabilitative, and augmenting technologies, robotics, aerospace and automotive industries, medical devices, pharmaceutical industry, pneumatic and hydraulic machines, agriculture, civil engineering, oil & gas, energy & power, water and wastewater treatment etc.
Description of Approach:
The CRFC Valve differs from valves currently on the market in its small size, lightweight, low cost, efficiency, and capability for proportional flow control. The CRFC Valve is a 3-way 3-position valve and utilizes a servo to implement a choking mechanism that proportionally lessens or widens the inlet opening of the latex tubing through which fluid flows.
The curved element attached to servo is used similarly to a cam mechanism, with two spherical cam followers (beads). The two tubes serving as the flow channels, allow for bi-directional fluid flow. Of the two tubes, at least one or both are closed at any given point in time. One tube serves as a fluid input for an attached system, and the other tube is the release tube.
The CRFC valve can be configured to open or close the fluid tubes by any degree between fully closed and fully open. The degree of opening can be directly controlled by the rotation angle of the servo motor. The servo increases or decreases tension in the strings constricting flow through the fluid tubes. With an increase in tension, the opening size becomes smaller, and with a decrease in tension, the opening gets larger. The fluid flow is linearly related to the size of the opening and is, therefore, proportional to the angle rotation of the servo.
This highly efficient and affordable valve currently uses low-cost materials such as a 3D-printed casing, thin surgical latex tubing, canvas fabric, and a micro servo. It has a total mass of 28 grams. The estimated average cost of the CRFC valve is around $10 USD. The CRFC Valve can be also easily customized for large range of various applications; it can be made of different materials, re-dimensioned, and utilize variety of servo motor units.
The CRFC Valve is lighter, smaller, more compact, more controllable, and less expensive than any other similar valve currently on the market. The CRFC Valve exhibits relatively fast response times with very little difference between water and air mediums.
The CRFC Valve can also work in junction with the Hydro Muscle system (see W14-030). When integrated, Hydro Muscles and the CRFC Valve may be utilized as modular building blocks for robots that can be rapidly assembled and utilized as either perform-alone or wearable robotic systems.
The only commercially available, electronically controlled valves in the same cost range as the CRFC valve that can support similar flows (>2.5 l/min and >0.2 Ml/min for water and air respectively) and pressures (>100 PSI or 0.7 MPa) are simple on-off solenoid valves. In difference, the CRFC valve’s servo motor finely controls orifice size in a continuous fashion. Still further, the CRFC valve occupies <40 cubic centimeters (~2.4 cubic inches) volume and has a mass of only 28 grams (~0.06lb); it takes up only 1/6th of the volume and 1/10th of the weight of the best on-off commercially available valve in the same cost range. Finally, the CRFC Valve exhibits relatively fast response times with very little difference between water and air mediums; the CRFC response time to fully close or to fully open are ~65 ms, which is comparable to response time of on-off valves priced roughly 10 times more than the CRFC valve.