Effect of the forces of one-way magnetic attraction on the reliability of the bearing unit of the traction switched reluctance motor

The subject of the research is a traction switched reluctance motor with an uneven air gap. The main purpose of the work is to determine the forces of one-way magnetic attraction, evaluate and analyze these forces, develop measures to reduce the forces to an acceptable value. In the article, the forces of disbalancement and the forces of one-way magnetic attraction are considered in the relationship. The finite element method was used to determine the main parameters of the switched reluctance motor. The studies were carried out for two idealized variants of the location of the rotor rotation axis. In the first case, the axis of rotation is combined with the axis of symmetry of the stator. The second option considers the case of displacement of the axis of rotation together with the axis of symmetry of the rotor. It is determined that the resulting force of one-way magnetic attraction with an uneven air gap reaches significant values and significantly exceeds the permissible values. An algorithm for calculating the characteristics of a switched reluctance motor is proposed, which takes into account the tolerances for the manufacture of its design elements. The algorithm allows you to adjust the requirements for the bearings used, ensure the required level of reliability of the traction switched reluctance motor (SRM) and predict the level of vibration and noise.

Magnetic Nanoparticle-Containing Supports as Carriers of Immobilized Enzymes: Key Factors Influencing the Biocatalyst Performance

In this short review (Perspective), we identify key features of the performance of biocatalysts developed by the immobilization of enzymes on the supports containing magnetic nanoparticles (NPs), analyzing the scientific literature for the last five years. A clear advantage of magnetic supports is their easy separation due to the magnetic attraction between magnetic NPs and an external magnetic field, facilitating the biocatalyst reuse. This allows for savings of materials and energy in the biocatalytic process. Commonly, magnetic NPs are isolated from enzymes either by polymers, silica, or some other protective layer. However, in those cases when iron oxide NPs are in close proximity to the enzyme, the biocatalyst may display a fascinating behavior, allowing for synergy of the performance due to the enzyme-like properties shown in iron oxides. Another important parameter which is discussed in this review is the magnetic support porosity, especially in hierarchical porous supports. In the case of comparatively large pores, which can freely accommodate enzyme molecules without jeopardizing their conformation, the enzyme surface ordering may create an optimal crowding on the support, enhancing the biocatalytic performance. Other factors such as surface-modifying agents or special enzyme reactor designs can be also influential in the performance of magnetic NP based immobilized enzymes.

The role of thermal diffusion, particle clusters, hydrodynamic and magnetic forces on the flow behaviour of magneto-polymer composites

In this paper, we study the shear-induced flow of magneto-polymer composites, consisting of dispersions of magnetic particles in solutions of polymers, as a competition between the colloidal forces amid particles and their bulk transport induced by the hydrodynamic forces. For this aim, we analyse the role of different experimental parameters. Firstly, by using only solutions of a well-known anionic polymer (sodium alginate), we provoke a moderate hindering of particle movement, but keeping the liquid-like state of the samples. On the contrary, a gel-like behaviour is conferred to the samples when a cationic polymer (chitosan) is additionally added, which further reduces the particle movement. We analyse the effect of an applied magnetic field, which is opposed to particle transport by hydrodynamic forces, by inducing magnetic attraction between the particles. We perform the analysis under both stationary and oscillatory shear. We show that by using dimensionless numbers the differences between samples and experimental conditions are emphasized. In all cases, as expected, the transport of particles driven by bulk hydrodynamic forces dominates at high values of the shear rate. This article is part of the theme issue ‘Transport phenomena in complex systems (part 1)’.

Unexpected magnetic attraction: Evidence for an organized energy field in the human body

Introduction & Background: In recent months unexpected reports have surfaced claiming the presence of magnetic attraction in the shoulder regions of subjects who had recently received the COVID-19 vaccination. Purpose: To determine if such claims are legitimate or spurious. Methods: A prospective observational study was performed utilizing standard neodymium magnets and non-magnetized paper clips in a rigorously standardized application protocol. Magnets and paper clips were applied over various regions of both deltoid muscles. The attraction score was calculated by adding one point for each pole of the magnet that attached to each arm over the deltoid muscle for a maximum score of 4. Likewise, three sizes of paper clips were tested with a maximum score of 6. The field score was calculated by adding the magnet score to the paper clip score for a maximum score of 10 points

Study for a Wall-Climbing Robot Magnetic Attraction Force of An Electronically Controlled Permanent Magnet

With the advancement in science and technology, a wall-climbing robot attached to the ship's outer surface is increasingly replacing humans in the rust removal. The magnetic force is not just the adsorption force but also the moving resistance force, which is currently the technological bottleneck in wall-climbing robotics based on magnetic adsorption. This paper proposes a novel wall-climbing robot based on electrically controlled permanent magnet technology to solve this problem. An electrically controlled permanent magnetic wall-climbing robot is proposed to realize the function of magnetization and demagnetization by changing the pulse current. The results of the experiments reveal that the magnetizing force is adequately adsorbed on the ship's outer surface. The magnetic attraction force is close to 0 N during demagnetization, meaning that the system is fully unloaded, as predicted by the theoretical analysis.

Switched reluctance traction motor with improved indicators of the reliability of bearing units for an electric rolling stoсk

Aim: Establishment of preconditions for the introduction of a switched reluctance motor into the system of traction drive of an electric rolling stock by improving the performance of the bearing unit. Methods: Calculations were carried out using the finite element method. Results: It was found that the calculated values ​​of force of a one-way magnetic attraction applied to the bearing unit are tens of times higher than the permissible values. The result is accelerated wear and failure of the bearings. An algorithm is proposed which takes into account the influence of one-way magnetic attraction forces in an uneven air gap. Conclusion: The algorithm makes it possible to change the production cycle and improve the consumer quality of the switched reluctance traction motor.

A novel series-parallel hybrid robot for climbing transmission tower

Purpose The purpose of this paper is to describe the design and development of a novel series-parallel robot, which aims to climb on the transmission tower. Design methodology approach This study introduces a hybrid robot, which consists of adsorption and two 3-degree of freedom (DOF) translation parallel legs connected by a body linkage. The DOF of the legs ensures that the robot can move on the climbing plane, also contribute to a compact design of the robot. An electromagnet is used to adsorb onto the transmission tower, simplifying the overall structure. Based on the robot design, this paper further defines its climbing gait and adopt the 6th B-spline curves for climbing trajectory planning under different working environments. Findings The developed prototype that implements the design of the robot, which was used in simulation and experiments, showing that the robot is capable of climbing in the test environments with the planned climbing gait. Originality value The hybrid robot is able to climb under varying degrees of inclinations and cross the obstacles, and the magnetic attraction can ensure stable climbing.