Angular displacement

About: Angular displacement is a research topic. Over the lifetime, 5102 publications have been published within this topic receiving 46081 citations. The topic is also known as: rotational displacement.

Hand wheel actuator having stationary hub

Abstract: A hand wheel actuator having a stationary hub is provided by a housing supporting a first shaft via bearings such that it is rotatable about its own axis. The first shaft has an upper end configured for attaching a hand wheel. The actuator also includes a position sensor for detecting an angular displacement of the first shaft from a selected origin and producing a signal indicative of the angular displacement and an electric motor in operative communication with the first shaft for providing feedback to a driver. A steering post is maintained in a fixed position with respect to the housing for maintaining the hub in a fixed position centrally of the hand wheel, so that the hub faces the driver when the hand wheel is operated. The steering post extends along an axis of rotation of the hand wheel and through the first shaft, which is fixed to the hand wheel and rotates therewith.

Flutter analysis of a two-dimensional airfoil with cubic non-linear restoring force

Abstract: Flutter analysis of a two-dimensional airfoil with a cubic nonlinear restoring force in the pitch degree of freedom is investigated. The structural dynamic equations of motion are integrated by a time marching finite difference scheme. Flutter is determined from conditions which give rise to either a divergent or limit-amplitude solution. Case studies using various airfoil parameters and coefficients of the non-linear term in the restoring force are carried out. The effect of initial conditions is studied by varying the displacement from equilibrium of the pitch angle at the start of the airfoil motion. For a soft spring, an increase in the initial angular displacement can induce flutter to occur below the linear flutter speed. Factors that have stabilizing and destabilizing effects are investigated. For a hard spring, divergent flutter is not encountered. Instead, the oscillations maintain a self-limited amplitude which is independent of initial angular displacement. The effects of airfoil parameters on the amplitudes of heave and pitch motions are studied.

Systems and methods for fabricating displacement scales

Abstract: Methods and systems for forming a displacement scale comprising TIR prisms on a substrate are described. A system for forming the displacement scale includes one or more rollers having a pattern of total internal reflection (TIR) prism features in negative relief. As the rollers are rotated, the scale is formed on the substrate. The rollers may also include pattern features in negative relief. Rotation of the rollers simultaneously forms the displacement scale and the pattern features on the substrate. The TIR prism features of the displacement scale may be oriented to provide measurement of one or more of lateral displacement, longitudinal displacement and angular displacement.

Detection of angular location of unbalance of a rotor and positioning of the location to a predetermined angular position

Abstract: In a dynamic balancing machine for measuring amount and angular location of unbalance of a rotor piece during rotating the rotor piece by a drive motor, in order to position automatically the unbalance angular location to a predetermined angular position on bearings at a time of detection of the unbalance, a preset counter is used for providing a signal to stop the drive motor. Angular pulses each of which indicates rotation of the test rotor piece over a unit angular extent are generated by a rotary encoder, and phase indicating pulses are formed from the vibration signal from a vibration velocity pickup. After constant rotation of the drive motor, motor speed is reduced by a motor speed reduction signal, and, thereafter, the preset counter begins to count the angular pulses in response to presence of one pulse of the phase indicating pulses. When the preset counter counts up to a number preset therein, the drive motor stops, then the unbalance location is positioned to an angular position which is determined by the number in the preset counter and the unit angular extent. An automatic marking device is fixedly disposed at the predetermined stop angular position and is driven after the motor stops. Thus, it is correctly and automatically performed to mark the unbalance location onto the test rotor piece.