Topic
Mechanical efficiency
About: Mechanical efficiency is a research topic. Over the lifetime, 523 publications have been published within this topic receiving 5943 citations. The topic is also known as: efficiency.
Papers published on a yearly basis
Papers
TL;DR: In this article, a computational model is proposed for the prediction of friction-related mechanical efficiency losses of parallel-axis gear pairs, which incorporates a gear load distribution model, a friction model, and a mechanical efficiency formulation to predict the instantaneous mechanical efficiency of a gear pair under typical operating, surface, and lubrication conditions.
Abstract: A computational model is proposed for the prediction of friction-related mechanical efficiency losses of parallel-axis gear pairs. The model incorporates a gear load distribution model, a friction model, and a mechanical efficiency formulation to predict the instantaneous mechanical efficiency of a gear pair under typical operating, surface, and lubrication conditions. The friction model uses a new friction coefficient formula obtained by using a validated non-Newtonian thermal elastohydrodynamic lubrication (EHL) model in conjunction with a multiple linear regression analysis. The load and friction coefficient, distribution predictions are used to compute instantaneous torque/ power losses and the mechanical efficiency of a gear pair at any given rotational position. Efficiency measurements from gear pairs having various gear designs and surface treatments are compared to model predictions. Mechanical efficiency predictions are shown to be within 0.1% of the measured values, indicating that the proposed efficiency model is accurate. Results of a parametric study are presented at the end to highlight the influence of key basic gear geometric parameters, tooth modifications, operating conditions, surface finish, and lubricant properties on mechanical efficiency losses.
316 citations
TL;DR: In this article, the authors proposed an on-line energy efficiency monitoring system for CNC machine tools without using any torque sensor or dynamometer, which leads to a decreased implementation cost.
256 citations
1 Nov 2004
TL;DR: In this paper, a gearless wheel motor drive system specifically designed for fuel cell electric and hybrid electric vehicle propulsion application is presented, which includes a liquid-cooled axial flux permanent-magnet machine designed to meet the direct drive requirements.
Abstract: This paper presents a gearless wheel motor drive system specifically designed for fuel cell electric and hybrid electric vehicle propulsion application. The system includes a liquid-cooled axial flux permanent-magnet machine designed to meet the direct-drive requirements. The machine design implements techniques to increase the machine inductance in order to improve machine constant power range and high-speed efficiency. The implemented technique reduces machine spin loss to further improve efficiency. The machine design also optimizes the placement of magnets in the rotor to reduce cogging and ripple torque. An original cooling system arrangement based on the use of high thermal conductivity epoxy joining machine stator and liquid-cooled aluminum casing allows the very effective removal of machine power loss. Design details and experimental results are presented
238 citations
7 Nov 2002
TL;DR: In this paper, a linear permanent magnet synchronous machine is compared to the transverse flux machine in a basic design study for a wave energy converter, and the latter machine is identified as offering the best potential.
Abstract: Wave power devices traditionally use conventional rotary electrical machines for power conversion. However hydraulic systems or air turbines are required to convert the low reciprocating motion of the wave device to rotation at 1500 rpm. The concept of a direct drive system is introduced, in which a reciprocating electrical machine is driven at the same speed as the device. A linear permanent magnet synchronous machine is compared to the transverse flux machine in a basic design study for this application. The latter machine is identified as offering the best potential. Electromagnetic and electric circuit models are developed to investigate the performance of the transverse flux machine in a wave energy converter. Measures are suggested to optimise the performance of the machine.
225 citations
1 Mar 1997
TL;DR: In this article, the authors compared the performance predictions made using a new model of the brushless doubly-fed machine with measurements made on a laboratory test machine, and the agreement between measurement and prediction was shown to be very good.
Abstract: The paper compares the performance predictions made using a new model of the brushless doubly-fed machine with measurements made on a laboratory test machine. The agreement between measurement and prediction is shown to be very good. The synchronous behaviour of the machine is shown to be very similar to that of a DC-excited synchronous machine, with the shaft torque determining the input power and the power factor being controlled by the voltage applied to one of the windings. The effect of magnetic saturation is discussed, and operating limits based on maximum flux and current limits are investigated.
137 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2021 | 11 |
| 2020 | 21 |
| 2019 | 32 |
| 2018 | 21 |
| 2017 | 36 |
| 2016 | 37 |