Physics Investigatory Project Class 113/13/2021
The power loss also increases if the load pressures vary a lot.The fluid is controlled directly or automatically by control valves and distributed through hoses and tubes.In normal cases, hydraulic ratios are combined with a mechanical force or torque ratio for optimum machine designs such as boom movements and trackdrives for an excavator.
If the force exerted on C1 is 10 lbf, the force exerted by C2 is 1000 lbf because C2 is a hundred times larger in area ( S r ) as C1. The downside to this is that you have to move C1 a hundred inches to move C2 one inch. The most common use for this is the classical hydraulic jack where a pumping cylinder with a small diameter is connected to the lifting cylinder with a large diameter. This combination is actually the same type of force multiplication as the cylinder example (1) just that the linear force in this case is a rotary force, defined as torque. The path taken by hydraulic fluid is called a hydraulic circuit of which there are several types. ![]() The flow is returned to tank through the control valves open center; that is, when the control valve is centered, it provides an open return path to tank and the fluid is not pumped to a high pressure. Otherwise, if the control valve is actuated it routes fluid to and from an actuator and tank. The fluids pressure will rise to meet any resistance, since the pump has a constant output. If the pressure rises too high, fluid returns to tank through a pressure relief valve. Physics Investigatory Project Class 11 Series This TypeMultiple control valves may be stacked in series This type of circuit can use inexpensive, constant displacement pumps. The pumps vary their flow rate, pumping very little hydraulic fluid until the operator actuates a valve. The valves spool therefore doesnt need an open center return path to tank. Multiple valves can be connected in a parallel arrangement and system pressure is equal for all valves. Pump pressure always equals the pressure setting for the pump regulator. Pump delivers flow according to required sum of flow to the consumers. The CP-system generates large power losses if the machine works with large variations in load pressure and the average system pressure is much lower than the pressure setting for the pump regulator. New hydraulic functions can easily be added and the system is quick in response. Same basic configuration as standard CP-system but the pump is unloaded to a low stand-by pressure when all valves are in neutral position. Not so fast response as standard CP but pump lifetime is prolonged. The LS-system also requires additional logical valves and compensator valves in the directional valves, thus it is technically more complex and more expensive than the CP-system. The LS-system generates a constant power loss related to the regulating pressure drop for the pump regulator.
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