ingångskraft

Ingångskraft is the force that is applied to the input side of a mechanical system or structure, initiating motion, deformation, or energy transfer. It is the driving force entering a mechanism, as opposed to the force that acts on the output side.

In mechanical systems, ingångskraft relates to other forces through the system’s geometry and dynamics. In a lever, the input force F_in applied at a distance r_in produces a input torque τ_in = F_in · r_in. The output torque τ_out depends on the load and the lever arms, with an ideal mechanical advantage given by r_in/r_out, which also relates the output force F_out to the input force by F_out = F_in · (r_in/r_out). In rotating gear systems, input torque and output torque are linked by gear ratios; the corresponding forces depend on the geometry of the gears and the radii involved.

Examples of ingångskraft in practice include a hydraulic cylinder where the input force is F_in = P · A, with P the fluid pressure and A the piston area, and an electric motor-driven actuator where electrical energy is converted into mechanical input force. In dynamic analyses, ingångskraft is often the driving variable in Newton’s second law (m a = F_in − F_load − damping), determining acceleration and motion of the system.

In control engineering and system modeling, ingångskraft is treated as an input signal that governs the behavior of the system, and it can be related to input power, P_in = F_in · v_in, in cases where velocity and direction are aligned. Overall, ingångskraft is a fundamental concept for understanding how external forces drive mechanical and electromechanical systems.