Search results for "Torque"
showing 10 items of 373 documents
Field‐circuit analysis of construction modifications of a torus‐type PMDC motor
2003
This paper presents the field‐circuit analysis of a disc‐type torus DC motor with permanent magnets. Calculations of the magnetic field are carried out using the finite element method (FEM) in the 3D space. The integral quantities like the ripple‐cogging torque, back electromotive force, flux linkage, self and mutual inductances of the winding are analyzed. The electromagnetic torque is comparatively determined from the Maxwell stress tensor and co‐energy methods. Based on the 3D magnetic field calculations, the lumped‐parameter model of the tested motor is constructed, taking into account an electronic power converter as well. For comparison, various permanent magnet widths and teeth thick…
Different Permanent-Magnet Structures and their Influence on the Torque of Small DC Motors
1995
The design of permanent-magnet DC micromotors implies solving a number of problems. A few of them belong to all DC micromotors, i.e. size and number of rotor slots, width of air gap, external stator and internal rotor diameter, ratio of length to rotor diameter etc.1. One problem, certainly not the lowest in importance is, however, specific2, i.e. the choice of the most convenient permanent magnet for prescribed specifications of the micromotor. To date the progress in the production of permanent magnets has made it possible to work out different structures of motors and, for each structure, the most suitable permanent magnet for specified applications. Rare-earth permanent magnets and, in …
Modeling and simulation of a VCM micromotor and its potential applications
2013
This paper presents the modeling and simulation of a VCM electrostatic micromotor with a new FEM analysis and implementation method, in order to determine the electrical parameters of the model and the generated electrostatic torque. Both the modeling and the simulation have been achieved using several software programs. In particular, the geometric model created with AUTOCAD has been imported to the FEMM program for the finite-element-method analysis. Then, with the LUA and MATLAB simulation programs, the parameters of the model and the related electrostatic torque have been calculated. The results obtained from this work have been compared with those reported in other scientific papers, s…
Finite-element performance comparison of IPMSMs with unsymmetrical double-layer windings
2017
This paper presents a comparison of the performances between IPMSMs (Interior Permanent Magnet Synchronous Machine) with a symmetrical and with two different types of unsymmetrical windings. The aim is to demonstrate that the adoption of slightly unsymmetrical windings does not significantly affect the performances of the machines, both in terms of cogging torque and torque/load angle characteristics, providing also the advantage of a higher possibility of choice in terms of slot number/poles ratio. More in particular, an IPMSM model (named IPMSM-1) derived from a commercial geometry equipped with a symmetrical winding is analyzed by using a Finite Element Method (FEM) approach. The simulat…
On the use of a powder rheometer to characterize the powder flowability at low consolidation with torque resistances
2017
The Anton Paar Powder Cell was used to measure the torque necessary to rotate an impeller in beds of glass beads, sand and alumina powders aerated between no aeration to the minimum for fluidization. Measured torque values depend on the material tested, on the air flow rate applied, on the impeller depth and on the height of the impeller blade. The effect of the impeller depth is linear for low impeller depth and is less than linear at high depth values. A model was developed for the interpretation of the experimental results based on the idea that the material is shearing on the surface described by the impeller rotation. The model allows to estimate an effectiveness of the impeller in the…
Assistive robotic walker parameter identification for estimation of human thrust without force sensors
2017
In this paper we propose a parameter identification procedure for the wheel-motor dynamic of a robotic walker, i.e. a commercial trolley for elderly people endowed with cognitive, sensing and guidance capabilities. The objective of the wheel-motor dynamic model is to generate a suitable time reference to be used in an estimation algorithm. The ultimate goal of the estimation algorithm is to retrieve the thrust, i.e. torque and force, that the older adult user of the robotic walker applies to the platform. These quantities are of paramount importance in order to adopt intelligent and comfortable walker guidance algorithms. The novelty of this approach is the avoidance of additional costly se…
Spin Pumping and Torque Statistics in the Quantum Noise Limit
2016
We analyze the statistics of charge and energy currents and spin torque in a metallic nanomagnet coupled to a large magnetic metal via a tunnel contact. We derive a Keldysh action for the tunnel barrier, describing the stochastic currents in the presence of a magnetization precessing with the rate $\Omega$. In contrast to some earlier approaches, we include the geometric phases that affect the counting statistics. We illustrate the use of the action by deriving spintronic fluctuation relations, the quantum limit of pumped current noise, and consider the fluctuations in two specific cases: the situation with a stable precession of magnetization driven by spin transfer torque, and the torque-…
Current signature based fault diagnosis of field-oriented and direct torque-controlled induction motor drives
2017
In this article, the operation of three-phase squirrel-cage induction motors is analysed under faulty conditions in closed loop with state-of-the-art controllers, namely, the field-oriented control...
Virtual simulation of an osseointegrated trans-humeral prosthesis: A falling scenario
2018
Abstract Introduction Traditional prosthetic solutions expose the amputee to numerous problems that limit his ability to safely perform the normal activities of daily life. In order to eliminate the problems related to the use of the traditional prosthesis with socket, a new technique was developed for fixing the prosthesis to the amputees based on the principle of osseointegration. The aim of this paper is to study and analyze the stress distribution on the interface between a trans-humeral osseointegrated prosthetic implant and the residual bone, identifying the most stressed areas and thus foreseeing possible failure phenomena of the entire prosthetic system and, after, to compare the st…
Design of RC joints equipped with hybrid trussed beams and friction dampers
2021
Abstract The challenge of this research consists in the first attempt to apply a dissipative friction connection to beam-to-column joints with semi-prefabricated Hybrid Steel-Trussed Concrete Beams (HSTCB) and RC pillars cast in-situ. Nowadays, HSTCBs are widely adopted in civil and industrial buildings and, therefore, it is required to evaluate their compliance with the capacity design criteria and their seismic energy dissipation capability. However, the design of the reinforcement of such beams usually lead to the adoption of large amount of steel within the panel zone which becomes potentially vulnerable to the effects of seismic cyclic actions and dramatically reduce the dissipation ca…