When learning about hydraulic-system power ratings, students should wear their gym clothes to class. The 1-HumanPower trainer from the Fluid Power Training Institute (FPTI) is a one-speed stationary bike apparatus, built to perform four tasks with various force requirements. Since students are the primary power source, completion of a task depends on his or her ability to maintain the necessary pedal speed.
As the student pedals, they move a belt drive that drives a fixed displacement pump. Pedaling faster increases fluid flow in the pump. Four solenoid directional-control valves control the actuators to complete four tasks: a double-acting, single-rod boom cylinder lifts and lowers a weight; a double-acting, single-rod boom cylinder extends and retracts the weight; a bidirectional fixed-displacement hydraulic motor drives a winch to lift the weight; and a bidirectional fixed displacement motor enables full crane rotation.
As students perform a specific task, they observe an instrument panel, consisting of an analog flow meter, pressure gauge, and digital tachometer, that indicates pump speed. The 1-HumanPower also comes with an all-digital panel upon request.
While viewing changes in pressure, pump speed, and fluid flow on the instrument panel, students can also observe their pedaling speeds upon use of a heavier weight and in different stages of the operations. The 1-HumanPower is also designed with different cylinder diameters. As a result, students are able to observe the relationship between cylinder cross-sectional area and pressure while pedaling.
The trainer’s various features allow students to physically experience the relationship between power ratings and force/pressure requirements. “Since the student is the prime mover, he or she can literally see how changes in pump speed affect actuator speed and feel how changes in flow and/or pressure affect horsepower; or in this case, human power,” says Rory McLaren of FRTI.
To find out more about the 1-HumanPower Trainer, call (801) 908-5456 or email [email protected]i.org.