Design of Gerotor Pump and Influence on Oil Supply System for Hybrid Transmission

Electric continuously variable transmission (E-CVT) is a vital part of the automobile in order to enhance the power coupling. The oil pump is an important power source component in the hybrid transmission system. Its efficiency exerts a significant impact on the efficiency of the oil supply system and even the hybrid transmission system. In this study, a gerotor pump is designed in line with the requirements of a certain type of hybrid electric vehicle. A Non-dominated Sorting Genetic Algorithm II (NSGA-II) genetic algorithm was employed to optimize the rotor tooth profile. The proportional-derivative (PD) control of the oil supply system was realized to lower the functional error of the oil supply system based on the AMESim simulation platform. In addition, the prototype test was performed to verify the rationality of the design.

A simple approach for air-gap permeance calculations in double excitation synchronous motor modelling with reluctance network

This article proposes an easy-to-use approximation for air-gap permeance calculations in a reluctance network. An extension of the overlap area between the stator and its corresponding rotor tooth to a position where the permeance becomes zero is also proposed. The advantage of this method is the simplification of conventional complex reluctance calculations while maintaining high accuracy. The proposed approach is applied to a double excitation synchronous motor, which usually requires a 3D simulation tool for the calculations. The validation of the accuracy of the proposed method on the flux linkage, back EMF, and electromagnetic torque are accomplished by comparison with those obtained from a conventional method and experimental data. The results of the comparison recommend the use of the proposed method for different electrical motor geometries.

Study on the effects of tooth profile design parameters of rotor to performance of vacuum pump

The vacuum pump usually used traditional curves such as the circular, cycloidal curves and their combinations to construct tooth profile. However, to increase efficiency and design flexibility for the vacuum pump, a novel rotor tooth profile for Roots rotor of vacuum pumps is proposed. Which is named “CEIEC” tooth profile and orderly composed of five significant segments, a circular arc for tooth tip, an epicycloid curve with variable extension, an involute, an enveloped epicycloid curve and a conjugated circular arc for tooth root. A numerical example is presented to evaluate the performance indices for proposed vacuum pump, including the hermeticity coefficients of the rotor mesh gap and tip gap.

Justification of optimal design and technological parameters of needle discs of the combined working body

The aim of the research is to improve soil tillage quality using combined working bodies in surface cultivation. There are various designs of combined tillage units including passive cultivators and active rotor-tooth working bodies cultivating land. However, an analysis of design and technological parameters of modern cultivators shows that they have a cumbersome design, required much metal and their quality indicators do not meet soil cultivation requirements. The article presents results of the studies on the influence of geometric and technological parameters of an additional battery of needle discs on land tillage quality. Using the research results, the land tillage has been improved and combined working bodies have been developed.

Refining the Torque Calculation Models in Designing Salient-Pole Inductor Motors

The article suggests a procedure for designing salient-pole inductor motors with developed tooth structures on the rotor and stator, which is supplemented by nonlinear calculation of a fragmentary magnetic circuit model with subsequently refining the saturation coefficient. The calculation is carried out using the semigraphical method before and after displacement of the rotor from the position of maximum air gap permeance by half the rotor tooth division with respect to teeth on the stator pole extension. Owing to introducing a weakly branched nonlinear magnetic circuit model into the design algorithm, in became possible to elaborate detail designs of motors for important electric drives of automatic systems, which confirmed their declared characteristics. It is noted that demagnetization of the magnetic circuit ferromagnetic areas, which is determined by calculation on the nonlinear model after turning the rotor by half the tooth division from the coaxial position, is the criterion of the correctly selected tooth area geometric parameters and electromagnetic loads.

Research on multi-objective optimization of switched flux motor based on improved NSGA-II algorithm

In order to optimize the local search efficiency of multi-objective parameters of flux switching permanent motor based on traditional NSGA-II algorithm, an improved NSGA-II (iNSGA-II) algorithm is proposed, with an anti-redundant mutation operator and forward comparison operation designed for quick identification of non-dominated individuals. In the initial stage of the iNSGA-II algorithm, half of the individual populations were randomly generated, while the other half was generated according to feature distribution information. Taking the flux switching permanent motor stator/rotor gap, permanent magnets width, stator tooth width, rotor tooth width and other parameters as optimization variables, the flux switching permanent motor maximum output shaft torque and minimum torque ripple are taken as optimization objectives, thus a multi-objective optimization model is established. Real number coding was adopted for obtaining the Pareto optimal solution of flux switching permanent motor structure parameters. The results showed that the iNSGA-II algorithm is better than the traditional NSGA-II on convergence. A 1.8L TOYOTA PRIUS model was selected as the prototype vehicle. By using the optimized parameters, a joint optimization simulation model was established by calling ADVISOR’s back-office function. The simulation results showed that the entire vehicle’s 100-km acceleration time is under 8 s and the battery’s SOC value maintains at 0.5–0.7 in the entire cycle, implying that the iNSGA-II algorithm optimizes the flux switching permanent motor design and is suitable for the initial design and optimizing calculation of the flux switching permanent motor.