China
Africa
Explore chapters and articles related to this topic
AC Machines
Published in Zeki Uğurata Kocabiyikoğlu, Electromechanical Energy Conversion, 2020
Slip rings are conductors that allow the coil to rotate while applying or receiving AC voltage and the brushes are continuously in contact with the rings. This simple single turn machine shown in Figure 7.1 can be operated as a motor or as a generator. If we rotate the coil, we will generate AC voltage from the terminals (brushes) and if we apply an AC voltage through the brushes, we will cause a torque which will rotate the coil. However, this single-loop machine can only be used for laboratory purposes because the amount of energy generated (or consumed) is and have to be quite small. The AC voltage generated by this simple electrical machine depends directly on the number of turns in the armature (the loop), the strength of the magnetic field (a permanent magnet in this case), and the speed of rotation (velocity) of the armature.
Rotary Transformer Design
Published in Colonel Wm. T. McLyman, Transformer and Inductor Design Handbook, 2017
There are many requirements to transfer signals and power across rotary interfaces. Most things that use slip rings or brushes can be replaced with a rotary transformer. Science instruments, antennas and solar arrays are elements needing rotary power transfer for certain spacecraft (S/C) configurations, such as a spin, stabilized (S/C). Delivery of signals and power has mainly been done by slip rings. There are problems in using slip rings for long life and high reliability: contact wear, noise, and contamination. Contact wear will lead to a conductive path to ground. This conductive path will generate noise and upset the original designed common-mode noise rejection. A simple slip ring assembly and a rotary transformer are shown in Figure 19-1. High data rates and poor slip ring life forced the Galileo (S/C) to replace the signal interface with rotary transformers. The use of a rotary transformer to transfer power on the Galileo (S/C) was contemplated, but it was thought the impact on the (S/C) delivery was too great. The rotary transformers on the Galileo (S/C) lasted the life of the spacecraft, from 1989 to 2003 without a glitch.
Structure of Measuring Systems
Published in Francis S. Tse, Ivan E. Morse, Measurement and Instrumentation in Engineering, 2018
An example of inherent insensitivity by means of a structural change in a strain measurement is shown in Fig. 3-50, in which a non-noise generating component is substituted for a noise-generating component. Signal from the strain gage on a rotating shaft is brought out by means of a pair of slip rings. A slip ring is a metallic ring on a shaft to transfer the signal from a rotating member to the stationary instrument. The ring is insulated from the shaft. A ballast circuit is used for the measurement, as shown in Fig. 3-50b. The circuit is unsatisfactory because of the unpredictable contact resistance at the brushes. The signal can be completely masked by the brush noise (see Prob. 1-4).
Effect of Elastic Contact Force on Tribological Characteristics of Current-carrying Roll Rings in Rotating Conductive Joints
Published in Tribology Transactions, 2023
Tianhua Chen, Chenfei Song, Zili Liu, Li Wang, Chao Sun, Xianjuan Pang, Yongzhen Zhang
With the rapid development of industry, the demand for high-power rotary connectors has increased. High-power electric transmission, as a method of power distribution, has a universal application in many electromechanical systems, including artificial space stations, satellites, radars, and wind generators (1). Traditional electric transmission devices in rotating parts mostly adopt sliding contacts, such as slip rings, which have high transmission efficiency and simple structural components. However, owing to their sliding contact characteristics, some disadvantages, such as high friction force, serious wear damage, and debris, lower the working performance and service life of the slip rings. Researchers have invented rolling electrical contact products based on the inherent advantages of tribological rolling contacts. These contact products typically have a structure comprising an inner raceway, an outer raceway, and elastic rings assembled between raceways (2–4). Compared to traditional slip rings, rolling rings have many advantages, including low noise, low resistance, long working life, and reliable performance.