The subject of this paper is a two-carrier planetary gear train (PGT) which was developed for a specific purpose. This PGT may be used for applications in which a negative transmission ratio in the range -3…-143 is required. In this case, the mechanical and dimensional properties of the PGT have been analyzed for nominal negative transmission ratios of -30 and -40. All possible combinations of simple component PGT ideal torque ratios providing those transmission ratios were obtained. Only the combinations providing the minimum radial dimensions of the PGT assembly were selected. Subsequent analysis has shown that the PGT radial dimensions will be minimized when the ratio of the reference diameters of the planetary unit ring gears is close to unity, meaning that the PGT casing will be cylindrical rather than stepped. This paper also provides an overview of the DVOBRZ software package used to synthesize the different gearbox layouts for the required transmission ratio, combined with a basic introduction to single speed two-carrier PGTs for better understanding. The DVOBRZ software was used to select all the acceptable gearboxes were selected from the set of generated PGTs according to the criteria of minimum dimensions and acceptable efficiency range. This set of PGTs was checked for kinematic feasibility and construction concepts were created for feasible layouts.
The full pinion engagement planetary gear trains are comparatively little known especially when it comes to the load sharing between the planets. In this paper, an attempt has been made to compensate for the lack of statistical data by extending the lumped mass model with the Monte Carlo simulation, thus generating thousands of different combinations for the pinhole position errors. A normal distribution has been assumed for the random variables. The static load sharing factor and the mesh load factor have been determined for nine scenarios with different mathematical expectations and mean deviations.
The up-to-the-date electrical systems for beamsteering of the phased antenna arrays are widely used; however, possessing significant drawbacks, including high losses, electromagnetic interference, and high power consumption. To overcome these challenges, microwave photonic systems, both discrete and integrated, have demonstrated outstanding potential. In this context, we discuss the two primary methods for beamsteering, i.e., true time delay (TTD) and phase shift (PS). This paper provides simulation results for a four-channel photonic integrated circuit (PIC) for beamsteering based on the TTD method. The PIC design could be implemented on any fabrication platform. The results demonstrate the approach’s feasibility and its potential to improve the performance of phased array antenna systems.
Very few experimental studies of full pinion engagement planetary gear trains have been published; therefore, their behavior under load is little known. In this paper, the results from the experimental studies of the above-mentioned gear trains are presented, whereby the bending stresses in the planet pins are displayed both in time and frequency domains by means of fast Fourier transform (FFT). The experiments are conducted on a mechanical closed-loop test rig, which was designed especially for the experiments. The bending stresses in the pins are measured by strain gauges, which are mounted in a double half-bridge configuration, thus showing the stresses in two perpendicular planes. The torque applied is 200 Nm. The radial run-out errors of the planets are measured and their relation to the pin loads are analyzed.